- description of the CIFS filesystem
coda.txt
- description of the CODA filesystem.
+configfs/
+ - directory containing configfs documentation and example code.
cramfs.txt
- info on the cram filesystem for small storage (ROMs etc)
devfs/
- directory containing devfs documentation.
+dlmfs.txt
+ - info on the userspace interface to the OCFS2 DLM.
ext2.txt
- info, mount options and specifications for the Ext2 filesystem.
hpfs.txt
- info and mount options for the NTFS filesystem (Windows NT).
proc.txt
- info on Linux's /proc filesystem.
+ocfs2.txt
+ - info and mount options for the OCFS2 clustered filesystem.
romfs.txt
- Description of the ROMFS filesystem.
smbfs.txt
--- /dev/null
+
+configfs - Userspace-driven kernel object configuation.
+
+Joel Becker <joel.becker@oracle.com>
+
+Updated: 31 March 2005
+
+Copyright (c) 2005 Oracle Corporation,
+ Joel Becker <joel.becker@oracle.com>
+
+
+[What is configfs?]
+
+configfs is a ram-based filesystem that provides the converse of
+sysfs's functionality. Where sysfs is a filesystem-based view of
+kernel objects, configfs is a filesystem-based manager of kernel
+objects, or config_items.
+
+With sysfs, an object is created in kernel (for example, when a device
+is discovered) and it is registered with sysfs. Its attributes then
+appear in sysfs, allowing userspace to read the attributes via
+readdir(3)/read(2). It may allow some attributes to be modified via
+write(2). The important point is that the object is created and
+destroyed in kernel, the kernel controls the lifecycle of the sysfs
+representation, and sysfs is merely a window on all this.
+
+A configfs config_item is created via an explicit userspace operation:
+mkdir(2). It is destroyed via rmdir(2). The attributes appear at
+mkdir(2) time, and can be read or modified via read(2) and write(2).
+As with sysfs, readdir(3) queries the list of items and/or attributes.
+symlink(2) can be used to group items together. Unlike sysfs, the
+lifetime of the representation is completely driven by userspace. The
+kernel modules backing the items must respond to this.
+
+Both sysfs and configfs can and should exist together on the same
+system. One is not a replacement for the other.
+
+[Using configfs]
+
+configfs can be compiled as a module or into the kernel. You can access
+it by doing
+
+ mount -t configfs none /config
+
+The configfs tree will be empty unless client modules are also loaded.
+These are modules that register their item types with configfs as
+subsystems. Once a client subsystem is loaded, it will appear as a
+subdirectory (or more than one) under /config. Like sysfs, the
+configfs tree is always there, whether mounted on /config or not.
+
+An item is created via mkdir(2). The item's attributes will also
+appear at this time. readdir(3) can determine what the attributes are,
+read(2) can query their default values, and write(2) can store new
+values. Like sysfs, attributes should be ASCII text files, preferably
+with only one value per file. The same efficiency caveats from sysfs
+apply. Don't mix more than one attribute in one attribute file.
+
+Like sysfs, configfs expects write(2) to store the entire buffer at
+once. When writing to configfs attributes, userspace processes should
+first read the entire file, modify the portions they wish to change, and
+then write the entire buffer back. Attribute files have a maximum size
+of one page (PAGE_SIZE, 4096 on i386).
+
+When an item needs to be destroyed, remove it with rmdir(2). An
+item cannot be destroyed if any other item has a link to it (via
+symlink(2)). Links can be removed via unlink(2).
+
+[Configuring FakeNBD: an Example]
+
+Imagine there's a Network Block Device (NBD) driver that allows you to
+access remote block devices. Call it FakeNBD. FakeNBD uses configfs
+for its configuration. Obviously, there will be a nice program that
+sysadmins use to configure FakeNBD, but somehow that program has to tell
+the driver about it. Here's where configfs comes in.
+
+When the FakeNBD driver is loaded, it registers itself with configfs.
+readdir(3) sees this just fine:
+
+ # ls /config
+ fakenbd
+
+A fakenbd connection can be created with mkdir(2). The name is
+arbitrary, but likely the tool will make some use of the name. Perhaps
+it is a uuid or a disk name:
+
+ # mkdir /config/fakenbd/disk1
+ # ls /config/fakenbd/disk1
+ target device rw
+
+The target attribute contains the IP address of the server FakeNBD will
+connect to. The device attribute is the device on the server.
+Predictably, the rw attribute determines whether the connection is
+read-only or read-write.
+
+ # echo 10.0.0.1 > /config/fakenbd/disk1/target
+ # echo /dev/sda1 > /config/fakenbd/disk1/device
+ # echo 1 > /config/fakenbd/disk1/rw
+
+That's it. That's all there is. Now the device is configured, via the
+shell no less.
+
+[Coding With configfs]
+
+Every object in configfs is a config_item. A config_item reflects an
+object in the subsystem. It has attributes that match values on that
+object. configfs handles the filesystem representation of that object
+and its attributes, allowing the subsystem to ignore all but the
+basic show/store interaction.
+
+Items are created and destroyed inside a config_group. A group is a
+collection of items that share the same attributes and operations.
+Items are created by mkdir(2) and removed by rmdir(2), but configfs
+handles that. The group has a set of operations to perform these tasks
+
+A subsystem is the top level of a client module. During initialization,
+the client module registers the subsystem with configfs, the subsystem
+appears as a directory at the top of the configfs filesystem. A
+subsystem is also a config_group, and can do everything a config_group
+can.
+
+[struct config_item]
+
+ struct config_item {
+ char *ci_name;
+ char ci_namebuf[UOBJ_NAME_LEN];
+ struct kref ci_kref;
+ struct list_head ci_entry;
+ struct config_item *ci_parent;
+ struct config_group *ci_group;
+ struct config_item_type *ci_type;
+ struct dentry *ci_dentry;
+ };
+
+ void config_item_init(struct config_item *);
+ void config_item_init_type_name(struct config_item *,
+ const char *name,
+ struct config_item_type *type);
+ struct config_item *config_item_get(struct config_item *);
+ void config_item_put(struct config_item *);
+
+Generally, struct config_item is embedded in a container structure, a
+structure that actually represents what the subsystem is doing. The
+config_item portion of that structure is how the object interacts with
+configfs.
+
+Whether statically defined in a source file or created by a parent
+config_group, a config_item must have one of the _init() functions
+called on it. This initializes the reference count and sets up the
+appropriate fields.
+
+All users of a config_item should have a reference on it via
+config_item_get(), and drop the reference when they are done via
+config_item_put().
+
+By itself, a config_item cannot do much more than appear in configfs.
+Usually a subsystem wants the item to display and/or store attributes,
+among other things. For that, it needs a type.
+
+[struct config_item_type]
+
+ struct configfs_item_operations {
+ void (*release)(struct config_item *);
+ ssize_t (*show_attribute)(struct config_item *,
+ struct configfs_attribute *,
+ char *);
+ ssize_t (*store_attribute)(struct config_item *,
+ struct configfs_attribute *,
+ const char *, size_t);
+ int (*allow_link)(struct config_item *src,
+ struct config_item *target);
+ int (*drop_link)(struct config_item *src,
+ struct config_item *target);
+ };
+
+ struct config_item_type {
+ struct module *ct_owner;
+ struct configfs_item_operations *ct_item_ops;
+ struct configfs_group_operations *ct_group_ops;
+ struct configfs_attribute **ct_attrs;
+ };
+
+The most basic function of a config_item_type is to define what
+operations can be performed on a config_item. All items that have been
+allocated dynamically will need to provide the ct_item_ops->release()
+method. This method is called when the config_item's reference count
+reaches zero. Items that wish to display an attribute need to provide
+the ct_item_ops->show_attribute() method. Similarly, storing a new
+attribute value uses the store_attribute() method.
+
+[struct configfs_attribute]
+
+ struct configfs_attribute {
+ char *ca_name;
+ struct module *ca_owner;
+ mode_t ca_mode;
+ };
+
+When a config_item wants an attribute to appear as a file in the item's
+configfs directory, it must define a configfs_attribute describing it.
+It then adds the attribute to the NULL-terminated array
+config_item_type->ct_attrs. When the item appears in configfs, the
+attribute file will appear with the configfs_attribute->ca_name
+filename. configfs_attribute->ca_mode specifies the file permissions.
+
+If an attribute is readable and the config_item provides a
+ct_item_ops->show_attribute() method, that method will be called
+whenever userspace asks for a read(2) on the attribute. The converse
+will happen for write(2).
+
+[struct config_group]
+
+A config_item cannot live in a vaccum. The only way one can be created
+is via mkdir(2) on a config_group. This will trigger creation of a
+child item.
+
+ struct config_group {
+ struct config_item cg_item;
+ struct list_head cg_children;
+ struct configfs_subsystem *cg_subsys;
+ struct config_group **default_groups;
+ };
+
+ void config_group_init(struct config_group *group);
+ void config_group_init_type_name(struct config_group *group,
+ const char *name,
+ struct config_item_type *type);
+
+
+The config_group structure contains a config_item. Properly configuring
+that item means that a group can behave as an item in its own right.
+However, it can do more: it can create child items or groups. This is
+accomplished via the group operations specified on the group's
+config_item_type.
+
+ struct configfs_group_operations {
+ struct config_item *(*make_item)(struct config_group *group,
+ const char *name);
+ struct config_group *(*make_group)(struct config_group *group,
+ const char *name);
+ int (*commit_item)(struct config_item *item);
+ void (*drop_item)(struct config_group *group,
+ struct config_item *item);
+ };
+
+A group creates child items by providing the
+ct_group_ops->make_item() method. If provided, this method is called from mkdir(2) in the group's directory. The subsystem allocates a new
+config_item (or more likely, its container structure), initializes it,
+and returns it to configfs. Configfs will then populate the filesystem
+tree to reflect the new item.
+
+If the subsystem wants the child to be a group itself, the subsystem
+provides ct_group_ops->make_group(). Everything else behaves the same,
+using the group _init() functions on the group.
+
+Finally, when userspace calls rmdir(2) on the item or group,
+ct_group_ops->drop_item() is called. As a config_group is also a
+config_item, it is not necessary for a seperate drop_group() method.
+The subsystem must config_item_put() the reference that was initialized
+upon item allocation. If a subsystem has no work to do, it may omit
+the ct_group_ops->drop_item() method, and configfs will call
+config_item_put() on the item on behalf of the subsystem.
+
+IMPORTANT: drop_item() is void, and as such cannot fail. When rmdir(2)
+is called, configfs WILL remove the item from the filesystem tree
+(assuming that it has no children to keep it busy). The subsystem is
+responsible for responding to this. If the subsystem has references to
+the item in other threads, the memory is safe. It may take some time
+for the item to actually disappear from the subsystem's usage. But it
+is gone from configfs.
+
+A config_group cannot be removed while it still has child items. This
+is implemented in the configfs rmdir(2) code. ->drop_item() will not be
+called, as the item has not been dropped. rmdir(2) will fail, as the
+directory is not empty.
+
+[struct configfs_subsystem]
+
+A subsystem must register itself, ususally at module_init time. This
+tells configfs to make the subsystem appear in the file tree.
+
+ struct configfs_subsystem {
+ struct config_group su_group;
+ struct semaphore su_sem;
+ };
+
+ int configfs_register_subsystem(struct configfs_subsystem *subsys);
+ void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
+
+ A subsystem consists of a toplevel config_group and a semaphore.
+The group is where child config_items are created. For a subsystem,
+this group is usually defined statically. Before calling
+configfs_register_subsystem(), the subsystem must have initialized the
+group via the usual group _init() functions, and it must also have
+initialized the semaphore.
+ When the register call returns, the subsystem is live, and it
+will be visible via configfs. At that point, mkdir(2) can be called and
+the subsystem must be ready for it.
+
+[An Example]
+
+The best example of these basic concepts is the simple_children
+subsystem/group and the simple_child item in configfs_example.c It
+shows a trivial object displaying and storing an attribute, and a simple
+group creating and destroying these children.
+
+[Hierarchy Navigation and the Subsystem Semaphore]
+
+There is an extra bonus that configfs provides. The config_groups and
+config_items are arranged in a hierarchy due to the fact that they
+appear in a filesystem. A subsystem is NEVER to touch the filesystem
+parts, but the subsystem might be interested in this hierarchy. For
+this reason, the hierarchy is mirrored via the config_group->cg_children
+and config_item->ci_parent structure members.
+
+A subsystem can navigate the cg_children list and the ci_parent pointer
+to see the tree created by the subsystem. This can race with configfs'
+management of the hierarchy, so configfs uses the subsystem semaphore to
+protect modifications. Whenever a subsystem wants to navigate the
+hierarchy, it must do so under the protection of the subsystem
+semaphore.
+
+A subsystem will be prevented from acquiring the semaphore while a newly
+allocated item has not been linked into this hierarchy. Similarly, it
+will not be able to acquire the semaphore while a dropping item has not
+yet been unlinked. This means that an item's ci_parent pointer will
+never be NULL while the item is in configfs, and that an item will only
+be in its parent's cg_children list for the same duration. This allows
+a subsystem to trust ci_parent and cg_children while they hold the
+semaphore.
+
+[Item Aggregation Via symlink(2)]
+
+configfs provides a simple group via the group->item parent/child
+relationship. Often, however, a larger environment requires aggregation
+outside of the parent/child connection. This is implemented via
+symlink(2).
+
+A config_item may provide the ct_item_ops->allow_link() and
+ct_item_ops->drop_link() methods. If the ->allow_link() method exists,
+symlink(2) may be called with the config_item as the source of the link.
+These links are only allowed between configfs config_items. Any
+symlink(2) attempt outside the configfs filesystem will be denied.
+
+When symlink(2) is called, the source config_item's ->allow_link()
+method is called with itself and a target item. If the source item
+allows linking to target item, it returns 0. A source item may wish to
+reject a link if it only wants links to a certain type of object (say,
+in its own subsystem).
+
+When unlink(2) is called on the symbolic link, the source item is
+notified via the ->drop_link() method. Like the ->drop_item() method,
+this is a void function and cannot return failure. The subsystem is
+responsible for responding to the change.
+
+A config_item cannot be removed while it links to any other item, nor
+can it be removed while an item links to it. Dangling symlinks are not
+allowed in configfs.
+
+[Automatically Created Subgroups]
+
+A new config_group may want to have two types of child config_items.
+While this could be codified by magic names in ->make_item(), it is much
+more explicit to have a method whereby userspace sees this divergence.
+
+Rather than have a group where some items behave differently than
+others, configfs provides a method whereby one or many subgroups are
+automatically created inside the parent at its creation. Thus,
+mkdir("parent) results in "parent", "parent/subgroup1", up through
+"parent/subgroupN". Items of type 1 can now be created in
+"parent/subgroup1", and items of type N can be created in
+"parent/subgroupN".
+
+These automatic subgroups, or default groups, do not preclude other
+children of the parent group. If ct_group_ops->make_group() exists,
+other child groups can be created on the parent group directly.
+
+A configfs subsystem specifies default groups by filling in the
+NULL-terminated array default_groups on the config_group structure.
+Each group in that array is populated in the configfs tree at the same
+time as the parent group. Similarly, they are removed at the same time
+as the parent. No extra notification is provided. When a ->drop_item()
+method call notifies the subsystem the parent group is going away, it
+also means every default group child associated with that parent group.
+
+As a consequence of this, default_groups cannot be removed directly via
+rmdir(2). They also are not considered when rmdir(2) on the parent
+group is checking for children.
+
+[Committable Items]
+
+NOTE: Committable items are currently unimplemented.
+
+Some config_items cannot have a valid initial state. That is, no
+default values can be specified for the item's attributes such that the
+item can do its work. Userspace must configure one or more attributes,
+after which the subsystem can start whatever entity this item
+represents.
+
+Consider the FakeNBD device from above. Without a target address *and*
+a target device, the subsystem has no idea what block device to import.
+The simple example assumes that the subsystem merely waits until all the
+appropriate attributes are configured, and then connects. This will,
+indeed, work, but now every attribute store must check if the attributes
+are initialized. Every attribute store must fire off the connection if
+that condition is met.
+
+Far better would be an explicit action notifying the subsystem that the
+config_item is ready to go. More importantly, an explicit action allows
+the subsystem to provide feedback as to whether the attibutes are
+initialized in a way that makes sense. configfs provides this as
+committable items.
+
+configfs still uses only normal filesystem operations. An item is
+committed via rename(2). The item is moved from a directory where it
+can be modified to a directory where it cannot.
+
+Any group that provides the ct_group_ops->commit_item() method has
+committable items. When this group appears in configfs, mkdir(2) will
+not work directly in the group. Instead, the group will have two
+subdirectories: "live" and "pending". The "live" directory does not
+support mkdir(2) or rmdir(2) either. It only allows rename(2). The
+"pending" directory does allow mkdir(2) and rmdir(2). An item is
+created in the "pending" directory. Its attributes can be modified at
+will. Userspace commits the item by renaming it into the "live"
+directory. At this point, the subsystem recieves the ->commit_item()
+callback. If all required attributes are filled to satisfaction, the
+method returns zero and the item is moved to the "live" directory.
+
+As rmdir(2) does not work in the "live" directory, an item must be
+shutdown, or "uncommitted". Again, this is done via rename(2), this
+time from the "live" directory back to the "pending" one. The subsystem
+is notified by the ct_group_ops->uncommit_object() method.
+
+
--- /dev/null
+/*
+ * vim: noexpandtab ts=8 sts=0 sw=8:
+ *
+ * configfs_example.c - This file is a demonstration module containing
+ * a number of configfs subsystems.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+
+
+
+/*
+ * 01-childless
+ *
+ * This first example is a childless subsystem. It cannot create
+ * any config_items. It just has attributes.
+ *
+ * Note that we are enclosing the configfs_subsystem inside a container.
+ * This is not necessary if a subsystem has no attributes directly
+ * on the subsystem. See the next example, 02-simple-children, for
+ * such a subsystem.
+ */
+
+struct childless {
+ struct configfs_subsystem subsys;
+ int showme;
+ int storeme;
+};
+
+struct childless_attribute {
+ struct configfs_attribute attr;
+ ssize_t (*show)(struct childless *, char *);
+ ssize_t (*store)(struct childless *, const char *, size_t);
+};
+
+static inline struct childless *to_childless(struct config_item *item)
+{
+ return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL;
+}
+
+static ssize_t childless_showme_read(struct childless *childless,
+ char *page)
+{
+ ssize_t pos;
+
+ pos = sprintf(page, "%d\n", childless->showme);
+ childless->showme++;
+
+ return pos;
+}
+
+static ssize_t childless_storeme_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page, "%d\n", childless->storeme);
+}
+
+static ssize_t childless_storeme_write(struct childless *childless,
+ const char *page,
+ size_t count)
+{
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ childless->storeme = tmp;
+
+ return count;
+}
+
+static ssize_t childless_description_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page,
+"[01-childless]\n"
+"\n"
+"The childless subsystem is the simplest possible subsystem in\n"
+"configfs. It does not support the creation of child config_items.\n"
+"It only has a few attributes. In fact, it isn't much different\n"
+"than a directory in /proc.\n");
+}
+
+static struct childless_attribute childless_attr_showme = {
+ .attr = { .ca_owner = THIS_MODULE, .ca_name = "showme", .ca_mode = S_IRUGO },
+ .show = childless_showme_read,
+};
+static struct childless_attribute childless_attr_storeme = {
+ .attr = { .ca_owner = THIS_MODULE, .ca_name = "storeme", .ca_mode = S_IRUGO | S_IWUSR },
+ .show = childless_storeme_read,
+ .store = childless_storeme_write,
+};
+static struct childless_attribute childless_attr_description = {
+ .attr = { .ca_owner = THIS_MODULE, .ca_name = "description", .ca_mode = S_IRUGO },
+ .show = childless_description_read,
+};
+
+static struct configfs_attribute *childless_attrs[] = {
+ &childless_attr_showme.attr,
+ &childless_attr_storeme.attr,
+ &childless_attr_description.attr,
+ NULL,
+};
+
+static ssize_t childless_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ struct childless *childless = to_childless(item);
+ struct childless_attribute *childless_attr =
+ container_of(attr, struct childless_attribute, attr);
+ ssize_t ret = 0;
+
+ if (childless_attr->show)
+ ret = childless_attr->show(childless, page);
+ return ret;
+}
+
+static ssize_t childless_attr_store(struct config_item *item,
+ struct configfs_attribute *attr,
+ const char *page, size_t count)
+{
+ struct childless *childless = to_childless(item);
+ struct childless_attribute *childless_attr =
+ container_of(attr, struct childless_attribute, attr);
+ ssize_t ret = -EINVAL;
+
+ if (childless_attr->store)
+ ret = childless_attr->store(childless, page, count);
+ return ret;
+}
+
+static struct configfs_item_operations childless_item_ops = {
+ .show_attribute = childless_attr_show,
+ .store_attribute = childless_attr_store,
+};
+
+static struct config_item_type childless_type = {
+ .ct_item_ops = &childless_item_ops,
+ .ct_attrs = childless_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct childless childless_subsys = {
+ .subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "01-childless",
+ .ci_type = &childless_type,
+ },
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 02-simple-children
+ *
+ * This example merely has a simple one-attribute child. Note that
+ * there is no extra attribute structure, as the child's attribute is
+ * known from the get-go. Also, there is no container for the
+ * subsystem, as it has no attributes of its own.
+ */
+
+struct simple_child {
+ struct config_item item;
+ int storeme;
+};
+
+static inline struct simple_child *to_simple_child(struct config_item *item)
+{
+ return item ? container_of(item, struct simple_child, item) : NULL;
+}
+
+static struct configfs_attribute simple_child_attr_storeme = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "storeme",
+ .ca_mode = S_IRUGO | S_IWUSR,
+};
+
+static struct configfs_attribute *simple_child_attrs[] = {
+ &simple_child_attr_storeme,
+ NULL,
+};
+
+static ssize_t simple_child_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ ssize_t count;
+ struct simple_child *simple_child = to_simple_child(item);
+
+ count = sprintf(page, "%d\n", simple_child->storeme);
+
+ return count;
+}
+
+static ssize_t simple_child_attr_store(struct config_item *item,
+ struct configfs_attribute *attr,
+ const char *page, size_t count)
+{
+ struct simple_child *simple_child = to_simple_child(item);
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ simple_child->storeme = tmp;
+
+ return count;
+}
+
+static void simple_child_release(struct config_item *item)
+{
+ kfree(to_simple_child(item));
+}
+
+static struct configfs_item_operations simple_child_item_ops = {
+ .release = simple_child_release,
+ .show_attribute = simple_child_attr_show,
+ .store_attribute = simple_child_attr_store,
+};
+
+static struct config_item_type simple_child_type = {
+ .ct_item_ops = &simple_child_item_ops,
+ .ct_attrs = simple_child_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+
+static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
+{
+ struct simple_child *simple_child;
+
+ simple_child = kmalloc(sizeof(struct simple_child), GFP_KERNEL);
+ if (!simple_child)
+ return NULL;
+
+ memset(simple_child, 0, sizeof(struct simple_child));
+
+ config_item_init_type_name(&simple_child->item, name,
+ &simple_child_type);
+
+ simple_child->storeme = 0;
+
+ return &simple_child->item;
+}
+
+static struct configfs_attribute simple_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *simple_children_attrs[] = {
+ &simple_children_attr_description,
+ NULL,
+};
+
+static ssize_t simple_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[02-simple-children]\n"
+"\n"
+"This subsystem allows the creation of child config_items. These\n"
+"items have only one attribute that is readable and writeable.\n");
+}
+
+static struct configfs_item_operations simple_children_item_ops = {
+ .show_attribute = simple_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations simple_children_group_ops = {
+ .make_item = simple_children_make_item,
+};
+
+static struct config_item_type simple_children_type = {
+ .ct_item_ops = &simple_children_item_ops,
+ .ct_group_ops = &simple_children_group_ops,
+ .ct_attrs = simple_children_attrs,
+};
+
+static struct configfs_subsystem simple_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "02-simple-children",
+ .ci_type = &simple_children_type,
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 03-group-children
+ *
+ * This example reuses the simple_children group from above. However,
+ * the simple_children group is not the subsystem itself, it is a
+ * child of the subsystem. Creation of a group in the subsystem creates
+ * a new simple_children group. That group can then have simple_child
+ * children of its own.
+ */
+
+struct simple_children {
+ struct config_group group;
+};
+
+static struct config_group *group_children_make_group(struct config_group *group, const char *name)
+{
+ struct simple_children *simple_children;
+
+ simple_children = kmalloc(sizeof(struct simple_children),
+ GFP_KERNEL);
+ if (!simple_children)
+ return NULL;
+
+ memset(simple_children, 0, sizeof(struct simple_children));
+
+ config_group_init_type_name(&simple_children->group, name,
+ &simple_children_type);
+
+ return &simple_children->group;
+}
+
+static struct configfs_attribute group_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *group_children_attrs[] = {
+ &group_children_attr_description,
+ NULL,
+};
+
+static ssize_t group_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[03-group-children]\n"
+"\n"
+"This subsystem allows the creation of child config_groups. These\n"
+"groups are like the subsystem simple-children.\n");
+}
+
+static struct configfs_item_operations group_children_item_ops = {
+ .show_attribute = group_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations group_children_group_ops = {
+ .make_group = group_children_make_group,
+};
+
+static struct config_item_type group_children_type = {
+ .ct_item_ops = &group_children_item_ops,
+ .ct_group_ops = &group_children_group_ops,
+ .ct_attrs = group_children_attrs,
+};
+
+static struct configfs_subsystem group_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "03-group-children",
+ .ci_type = &group_children_type,
+ },
+ },
+};
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * We're now done with our subsystem definitions.
+ * For convenience in this module, here's a list of them all. It
+ * allows the init function to easily register them. Most modules
+ * will only have one subsystem, and will only call register_subsystem
+ * on it directly.
+ */
+static struct configfs_subsystem *example_subsys[] = {
+ &childless_subsys.subsys,
+ &simple_children_subsys,
+ &group_children_subsys,
+ NULL,
+};
+
+static int __init configfs_example_init(void)
+{
+ int ret;
+ int i;
+ struct configfs_subsystem *subsys;
+
+ for (i = 0; example_subsys[i]; i++) {
+ subsys = example_subsys[i];
+
+ config_group_init(&subsys->su_group);
+ init_MUTEX(&subsys->su_sem);
+ ret = configfs_register_subsystem(subsys);
+ if (ret) {
+ printk(KERN_ERR "Error %d while registering subsystem %s\n",
+ ret,
+ subsys->su_group.cg_item.ci_namebuf);
+ goto out_unregister;
+ }
+ }
+
+ return 0;
+
+out_unregister:
+ for (; i >= 0; i--) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+
+ return ret;
+}
+
+static void __exit configfs_example_exit(void)
+{
+ int i;
+
+ for (i = 0; example_subsys[i]; i++) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+}
+
+module_init(configfs_example_init);
+module_exit(configfs_example_exit);
+MODULE_LICENSE("GPL");
--- /dev/null
+dlmfs
+==================
+A minimal DLM userspace interface implemented via a virtual file
+system.
+
+dlmfs is built with OCFS2 as it requires most of its infrastructure.
+
+Project web page: http://oss.oracle.com/projects/ocfs2
+Tools web page: http://oss.oracle.com/projects/ocfs2-tools
+OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
+
+All code copyright 2005 Oracle except when otherwise noted.
+
+CREDITS
+=======
+
+Some code taken from ramfs which is Copyright (C) 2000 Linus Torvalds
+and Transmeta Corp.
+
+Mark Fasheh <mark.fasheh@oracle.com>
+
+Caveats
+=======
+- Right now it only works with the OCFS2 DLM, though support for other
+ DLM implementations should not be a major issue.
+
+Mount options
+=============
+None
+
+Usage
+=====
+
+If you're just interested in OCFS2, then please see ocfs2.txt. The
+rest of this document will be geared towards those who want to use
+dlmfs for easy to setup and easy to use clustered locking in
+userspace.
+
+Setup
+=====
+
+dlmfs requires that the OCFS2 cluster infrastructure be in
+place. Please download ocfs2-tools from the above url and configure a
+cluster.
+
+You'll want to start heartbeating on a volume which all the nodes in
+your lockspace can access. The easiest way to do this is via
+ocfs2_hb_ctl (distributed with ocfs2-tools). Right now it requires
+that an OCFS2 file system be in place so that it can automatically
+find it's heartbeat area, though it will eventually support heartbeat
+against raw disks.
+
+Please see the ocfs2_hb_ctl and mkfs.ocfs2 manual pages distributed
+with ocfs2-tools.
+
+Once you're heartbeating, DLM lock 'domains' can be easily created /
+destroyed and locks within them accessed.
+
+Locking
+=======
+
+Users may access dlmfs via standard file system calls, or they can use
+'libo2dlm' (distributed with ocfs2-tools) which abstracts the file
+system calls and presents a more traditional locking api.
+
+dlmfs handles lock caching automatically for the user, so a lock
+request for an already acquired lock will not generate another DLM
+call. Userspace programs are assumed to handle their own local
+locking.
+
+Two levels of locks are supported - Shared Read, and Exlcusive.
+Also supported is a Trylock operation.
+
+For information on the libo2dlm interface, please see o2dlm.h,
+distributed with ocfs2-tools.
+
+Lock value blocks can be read and written to a resource via read(2)
+and write(2) against the fd obtained via your open(2) call. The
+maximum currently supported LVB length is 64 bytes (though that is an
+OCFS2 DLM limitation). Through this mechanism, users of dlmfs can share
+small amounts of data amongst their nodes.
+
+mkdir(2) signals dlmfs to join a domain (which will have the same name
+as the resulting directory)
+
+rmdir(2) signals dlmfs to leave the domain
+
+Locks for a given domain are represented by regular inodes inside the
+domain directory. Locking against them is done via the open(2) system
+call.
+
+The open(2) call will not return until your lock has been granted or
+an error has occurred, unless it has been instructed to do a trylock
+operation. If the lock succeeds, you'll get an fd.
+
+open(2) with O_CREAT to ensure the resource inode is created - dlmfs does
+not automatically create inodes for existing lock resources.
+
+Open Flag Lock Request Type
+--------- -----------------
+O_RDONLY Shared Read
+O_RDWR Exclusive
+
+Open Flag Resulting Locking Behavior
+--------- --------------------------
+O_NONBLOCK Trylock operation
+
+You must provide exactly one of O_RDONLY or O_RDWR.
+
+If O_NONBLOCK is also provided and the trylock operation was valid but
+could not lock the resource then open(2) will return ETXTBUSY.
+
+close(2) drops the lock associated with your fd.
+
+Modes passed to mkdir(2) or open(2) are adhered to locally. Chown is
+supported locally as well. This means you can use them to restrict
+access to the resources via dlmfs on your local node only.
+
+The resource LVB may be read from the fd in either Shared Read or
+Exclusive modes via the read(2) system call. It can be written via
+write(2) only when open in Exclusive mode.
+
+Once written, an LVB will be visible to other nodes who obtain Read
+Only or higher level locks on the resource.
+
+See Also
+========
+http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf
+
+For more information on the VMS distributed locking API.
--- /dev/null
+OCFS2 filesystem
+==================
+OCFS2 is a general purpose extent based shared disk cluster file
+system with many similarities to ext3. It supports 64 bit inode
+numbers, and has automatically extending metadata groups which may
+also make it attractive for non-clustered use.
+
+You'll want to install the ocfs2-tools package in order to at least
+get "mount.ocfs2" and "ocfs2_hb_ctl".
+
+Project web page: http://oss.oracle.com/projects/ocfs2
+Tools web page: http://oss.oracle.com/projects/ocfs2-tools
+OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
+
+All code copyright 2005 Oracle except when otherwise noted.
+
+CREDITS:
+Lots of code taken from ext3 and other projects.
+
+Authors in alphabetical order:
+Joel Becker <joel.becker@oracle.com>
+Zach Brown <zach.brown@oracle.com>
+Mark Fasheh <mark.fasheh@oracle.com>
+Kurt Hackel <kurt.hackel@oracle.com>
+Sunil Mushran <sunil.mushran@oracle.com>
+Manish Singh <manish.singh@oracle.com>
+
+Caveats
+=======
+Features which OCFS2 does not support yet:
+ - sparse files
+ - extended attributes
+ - shared writeable mmap
+ - loopback is supported, but data written will not
+ be cluster coherent.
+ - quotas
+ - cluster aware flock
+ - Directory change notification (F_NOTIFY)
+ - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
+ - POSIX ACLs
+ - readpages / writepages (not user visible)
+
+Mount options
+=============
+
+OCFS2 supports the following mount options:
+(*) == default
+
+barrier=1 This enables/disables barriers. barrier=0 disables it,
+ barrier=1 enables it.
+errors=remount-ro(*) Remount the filesystem read-only on an error.
+errors=panic Panic and halt the machine if an error occurs.
+intr (*) Allow signals to interrupt cluster operations.
+nointr Do not allow signals to interrupt cluster
+ operations.
T: git kernel.org:/pub/scm/linux/kernel/git/sfrench/cifs-2.6.git
S: Supported
+CONFIGFS
+P: Joel Becker
+M: Joel Becker <joel.becker@oracle.com>
+S: Supported
+
CIRRUS LOGIC GENERIC FBDEV DRIVER
P: Jeff Garzik
M: jgarzik@pobox.com
L: linux-nvidia@lists.surfsouth.com
S: Maintained
+ORACLE CLUSTER FILESYSTEM 2 (OCFS2)
+P: Mark Fasheh
+M: mark.fasheh@oracle.com
+P: Kurt Hackel
+M: kurt.hackel@oracle.com
+L: ocfs2-devel@oss.oracle.com
+W: http://oss.oracle.com/projects/ocfs2/
+S: Supported
+
OLYMPIC NETWORK DRIVER
P: Peter De Shrijver
M: p2@ace.ulyssis.student.kuleuven.ac.be
struct address_space_operations *aops = mapping->a_ops;
pgoff_t index;
unsigned offset, bv_offs;
- int len, ret = 0;
+ int len, ret;
down(&mapping->host->i_sem);
index = pos >> PAGE_CACHE_SHIFT;
page = grab_cache_page(mapping, index);
if (unlikely(!page))
goto fail;
- if (unlikely(aops->prepare_write(file, page, offset,
- offset + size)))
+ ret = aops->prepare_write(file, page, offset,
+ offset + size);
+ if (unlikely(ret)) {
+ if (ret == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ continue;
+ }
goto unlock;
+ }
transfer_result = lo_do_transfer(lo, WRITE, page, offset,
bvec->bv_page, bv_offs, size, IV);
if (unlikely(transfer_result)) {
kunmap_atomic(kaddr, KM_USER0);
}
flush_dcache_page(page);
- if (unlikely(aops->commit_write(file, page, offset,
- offset + size)))
+ ret = aops->commit_write(file, page, offset,
+ offset + size);
+ if (unlikely(ret)) {
+ if (ret == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ continue;
+ }
goto unlock;
+ }
if (unlikely(transfer_result))
goto unlock;
bv_offs += size;
unlock_page(page);
page_cache_release(page);
}
+ ret = 0;
out:
up(&mapping->host->i_sem);
return ret;
/*
* ->writepage to the the blockdev's mapping has to redirty the page so that the
- * VM doesn't go and steal it. We return WRITEPAGE_ACTIVATE so that the VM
+ * VM doesn't go and steal it. We return AOP_WRITEPAGE_ACTIVATE so that the VM
* won't try to (pointlessly) write the page again for a while.
*
* Really, these pages should not be on the LRU at all.
make_page_uptodate(page);
SetPageDirty(page);
if (wbc->for_reclaim)
- return WRITEPAGE_ACTIVATE;
+ return AOP_WRITEPAGE_ACTIVATE;
unlock_page(page);
return 0;
}
config EXT3_FS
tristate "Ext3 journalling file system support"
+ select JBD
help
This is the journaling version of the Second extended file system
(often called ext3), the de facto standard Linux file system
extended attributes for file security labels, say N.
config JBD
-# CONFIG_JBD could be its own option (even modular), but until there are
-# other users than ext3, we will simply make it be the same as CONFIG_EXT3_FS
-# dep_tristate ' Journal Block Device support (JBD for ext3)' CONFIG_JBD $CONFIG_EXT3_FS
tristate
- default EXT3_FS
help
This is a generic journaling layer for block devices. It is
- currently used by the ext3 file system, but it could also be used to
- add journal support to other file systems or block devices such as
- RAID or LVM.
+ currently used by the ext3 and OCFS2 file systems, but it could
+ also be used to add journal support to other file systems or block
+ devices such as RAID or LVM.
- If you are using the ext3 file system, you need to say Y here. If
- you are not using ext3 then you will probably want to say N.
+ If you are using the ext3 or OCFS2 file systems, you need to
+ say Y here. If you are not using ext3 OCFS2 then you will probably
+ want to say N.
To compile this device as a module, choose M here: the module will be
- called jbd. If you are compiling ext3 into the kernel, you cannot
- compile this code as a module.
+ called jbd. If you are compiling ext3 or OCFS2 into the kernel,
+ you cannot compile this code as a module.
config JBD_DEBUG
bool "JBD (ext3) debugging support"
source "fs/xfs/Kconfig"
+config OCFS2_FS
+ tristate "OCFS2 file system support (EXPERIMENTAL)"
+ depends on NET && EXPERIMENTAL
+ select CONFIGFS_FS
+ select JBD
+ select CRC32
+ select INET
+ help
+ OCFS2 is a general purpose extent based shared disk cluster file
+ system with many similarities to ext3. It supports 64 bit inode
+ numbers, and has automatically extending metadata groups which may
+ also make it attractive for non-clustered use.
+
+ You'll want to install the ocfs2-tools package in order to at least
+ get "mount.ocfs2".
+
+ Project web page: http://oss.oracle.com/projects/ocfs2
+ Tools web page: http://oss.oracle.com/projects/ocfs2-tools
+ OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
+
+ Note: Features which OCFS2 does not support yet:
+ - extended attributes
+ - shared writeable mmap
+ - loopback is supported, but data written will not
+ be cluster coherent.
+ - quotas
+ - cluster aware flock
+ - Directory change notification (F_NOTIFY)
+ - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
+ - POSIX ACLs
+ - readpages / writepages (not user visible)
+
config MINIX_FS
tristate "Minix fs support"
help
If unsure, say N.
+config CONFIGFS_FS
+ tristate "Userspace-driven configuration filesystem (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ configfs is a ram-based filesystem that provides the converse
+ of sysfs's functionality. Where sysfs is a filesystem-based
+ view of kernel objects, configfs is a filesystem-based manager
+ of kernel objects, or config_items.
+
+ Both sysfs and configfs can and should exist together on the
+ same system. One is not a replacement for the other.
+
+ If unsure, say N.
+
endmenu
menu "Miscellaneous filesystems"
obj-$(CONFIG_HOSTFS) += hostfs/
obj-$(CONFIG_HPPFS) += hppfs/
obj-$(CONFIG_DEBUG_FS) += debugfs/
+obj-$(CONFIG_CONFIGFS_FS) += configfs/
+obj-$(CONFIG_OCFS2_FS) += ocfs2/
--- /dev/null
+#
+# Makefile for the configfs virtual filesystem
+#
+
+obj-$(CONFIG_CONFIGFS_FS) += configfs.o
+
+configfs-objs := inode.o file.o dir.o symlink.o mount.o item.o
--- /dev/null
+/* -*- mode: c; c-basic-offset:8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * configfs_internal.h - Internal stuff for configfs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/list.h>
+
+struct configfs_dirent {
+ atomic_t s_count;
+ struct list_head s_sibling;
+ struct list_head s_children;
+ struct list_head s_links;
+ void * s_element;
+ int s_type;
+ umode_t s_mode;
+ struct dentry * s_dentry;
+};
+
+#define CONFIGFS_ROOT 0x0001
+#define CONFIGFS_DIR 0x0002
+#define CONFIGFS_ITEM_ATTR 0x0004
+#define CONFIGFS_ITEM_LINK 0x0020
+#define CONFIGFS_USET_DIR 0x0040
+#define CONFIGFS_USET_DEFAULT 0x0080
+#define CONFIGFS_USET_DROPPING 0x0100
+#define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR)
+
+extern struct vfsmount * configfs_mount;
+
+extern int configfs_is_root(struct config_item *item);
+
+extern struct inode * configfs_new_inode(mode_t mode);
+extern int configfs_create(struct dentry *, int mode, int (*init)(struct inode *));
+
+extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
+extern int configfs_make_dirent(struct configfs_dirent *,
+ struct dentry *, void *, umode_t, int);
+
+extern int configfs_add_file(struct dentry *, const struct configfs_attribute *, int);
+extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
+
+extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
+extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
+
+extern int configfs_pin_fs(void);
+extern void configfs_release_fs(void);
+
+extern struct rw_semaphore configfs_rename_sem;
+extern struct super_block * configfs_sb;
+extern struct file_operations configfs_dir_operations;
+extern struct file_operations configfs_file_operations;
+extern struct file_operations bin_fops;
+extern struct inode_operations configfs_dir_inode_operations;
+extern struct inode_operations configfs_symlink_inode_operations;
+
+extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname);
+extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
+
+struct configfs_symlink {
+ struct list_head sl_list;
+ struct config_item *sl_target;
+};
+
+extern int configfs_create_link(struct configfs_symlink *sl,
+ struct dentry *parent,
+ struct dentry *dentry);
+
+static inline struct config_item * to_item(struct dentry * dentry)
+{
+ struct configfs_dirent * sd = dentry->d_fsdata;
+ return ((struct config_item *) sd->s_element);
+}
+
+static inline struct configfs_attribute * to_attr(struct dentry * dentry)
+{
+ struct configfs_dirent * sd = dentry->d_fsdata;
+ return ((struct configfs_attribute *) sd->s_element);
+}
+
+static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
+{
+ struct config_item * item = NULL;
+
+ spin_lock(&dcache_lock);
+ if (!d_unhashed(dentry)) {
+ struct configfs_dirent * sd = dentry->d_fsdata;
+ if (sd->s_type & CONFIGFS_ITEM_LINK) {
+ struct configfs_symlink * sl = sd->s_element;
+ item = config_item_get(sl->sl_target);
+ } else
+ item = config_item_get(sd->s_element);
+ }
+ spin_unlock(&dcache_lock);
+
+ return item;
+}
+
+static inline void release_configfs_dirent(struct configfs_dirent * sd)
+{
+ if (!(sd->s_type & CONFIGFS_ROOT))
+ kfree(sd);
+}
+
+static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
+{
+ if (sd) {
+ WARN_ON(!atomic_read(&sd->s_count));
+ atomic_inc(&sd->s_count);
+ }
+ return sd;
+}
+
+static inline void configfs_put(struct configfs_dirent * sd)
+{
+ WARN_ON(!atomic_read(&sd->s_count));
+ if (atomic_dec_and_test(&sd->s_count))
+ release_configfs_dirent(sd);
+}
+
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * dir.c - Operations for configfs directories.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#undef DEBUG
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+DECLARE_RWSEM(configfs_rename_sem);
+
+static void configfs_d_iput(struct dentry * dentry,
+ struct inode * inode)
+{
+ struct configfs_dirent * sd = dentry->d_fsdata;
+
+ if (sd) {
+ BUG_ON(sd->s_dentry != dentry);
+ sd->s_dentry = NULL;
+ configfs_put(sd);
+ }
+ iput(inode);
+}
+
+/*
+ * We _must_ delete our dentries on last dput, as the chain-to-parent
+ * behavior is required to clear the parents of default_groups.
+ */
+static int configfs_d_delete(struct dentry *dentry)
+{
+ return 1;
+}
+
+static struct dentry_operations configfs_dentry_ops = {
+ .d_iput = configfs_d_iput,
+ /* simple_delete_dentry() isn't exported */
+ .d_delete = configfs_d_delete,
+};
+
+/*
+ * Allocates a new configfs_dirent and links it to the parent configfs_dirent
+ */
+static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd,
+ void * element)
+{
+ struct configfs_dirent * sd;
+
+ sd = kmalloc(sizeof(*sd), GFP_KERNEL);
+ if (!sd)
+ return NULL;
+
+ memset(sd, 0, sizeof(*sd));
+ atomic_set(&sd->s_count, 1);
+ INIT_LIST_HEAD(&sd->s_links);
+ INIT_LIST_HEAD(&sd->s_children);
+ list_add(&sd->s_sibling, &parent_sd->s_children);
+ sd->s_element = element;
+
+ return sd;
+}
+
+int configfs_make_dirent(struct configfs_dirent * parent_sd,
+ struct dentry * dentry, void * element,
+ umode_t mode, int type)
+{
+ struct configfs_dirent * sd;
+
+ sd = configfs_new_dirent(parent_sd, element);
+ if (!sd)
+ return -ENOMEM;
+
+ sd->s_mode = mode;
+ sd->s_type = type;
+ sd->s_dentry = dentry;
+ if (dentry) {
+ dentry->d_fsdata = configfs_get(sd);
+ dentry->d_op = &configfs_dentry_ops;
+ }
+
+ return 0;
+}
+
+static int init_dir(struct inode * inode)
+{
+ inode->i_op = &configfs_dir_inode_operations;
+ inode->i_fop = &configfs_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inode->i_nlink++;
+ return 0;
+}
+
+static int init_file(struct inode * inode)
+{
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &configfs_file_operations;
+ return 0;
+}
+
+static int init_symlink(struct inode * inode)
+{
+ inode->i_op = &configfs_symlink_inode_operations;
+ return 0;
+}
+
+static int create_dir(struct config_item * k, struct dentry * p,
+ struct dentry * d)
+{
+ int error;
+ umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+
+ error = configfs_create(d, mode, init_dir);
+ if (!error) {
+ error = configfs_make_dirent(p->d_fsdata, d, k, mode,
+ CONFIGFS_DIR);
+ if (!error) {
+ p->d_inode->i_nlink++;
+ (d)->d_op = &configfs_dentry_ops;
+ }
+ }
+ return error;
+}
+
+
+/**
+ * configfs_create_dir - create a directory for an config_item.
+ * @item: config_itemwe're creating directory for.
+ * @dentry: config_item's dentry.
+ */
+
+static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
+{
+ struct dentry * parent;
+ int error = 0;
+
+ BUG_ON(!item);
+
+ if (item->ci_parent)
+ parent = item->ci_parent->ci_dentry;
+ else if (configfs_mount && configfs_mount->mnt_sb)
+ parent = configfs_mount->mnt_sb->s_root;
+ else
+ return -EFAULT;
+
+ error = create_dir(item,parent,dentry);
+ if (!error)
+ item->ci_dentry = dentry;
+ return error;
+}
+
+int configfs_create_link(struct configfs_symlink *sl,
+ struct dentry *parent,
+ struct dentry *dentry)
+{
+ int err = 0;
+ umode_t mode = S_IFLNK | S_IRWXUGO;
+
+ err = configfs_create(dentry, mode, init_symlink);
+ if (!err) {
+ err = configfs_make_dirent(parent->d_fsdata, dentry, sl,
+ mode, CONFIGFS_ITEM_LINK);
+ if (!err)
+ dentry->d_op = &configfs_dentry_ops;
+ }
+ return err;
+}
+
+static void remove_dir(struct dentry * d)
+{
+ struct dentry * parent = dget(d->d_parent);
+ struct configfs_dirent * sd;
+
+ sd = d->d_fsdata;
+ list_del_init(&sd->s_sibling);
+ configfs_put(sd);
+ if (d->d_inode)
+ simple_rmdir(parent->d_inode,d);
+
+ pr_debug(" o %s removing done (%d)\n",d->d_name.name,
+ atomic_read(&d->d_count));
+
+ dput(parent);
+}
+
+/**
+ * configfs_remove_dir - remove an config_item's directory.
+ * @item: config_item we're removing.
+ *
+ * The only thing special about this is that we remove any files in
+ * the directory before we remove the directory, and we've inlined
+ * what used to be configfs_rmdir() below, instead of calling separately.
+ */
+
+static void configfs_remove_dir(struct config_item * item)
+{
+ struct dentry * dentry = dget(item->ci_dentry);
+
+ if (!dentry)
+ return;
+
+ remove_dir(dentry);
+ /**
+ * Drop reference from dget() on entrance.
+ */
+ dput(dentry);
+}
+
+
+/* attaches attribute's configfs_dirent to the dentry corresponding to the
+ * attribute file
+ */
+static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
+{
+ struct configfs_attribute * attr = sd->s_element;
+ int error;
+
+ error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
+ if (error)
+ return error;
+
+ dentry->d_op = &configfs_dentry_ops;
+ dentry->d_fsdata = configfs_get(sd);
+ sd->s_dentry = dentry;
+ d_rehash(dentry);
+
+ return 0;
+}
+
+static struct dentry * configfs_lookup(struct inode *dir,
+ struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
+ struct configfs_dirent * sd;
+ int found = 0;
+ int err = 0;
+
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (sd->s_type & CONFIGFS_NOT_PINNED) {
+ const unsigned char * name = configfs_get_name(sd);
+
+ if (strcmp(name, dentry->d_name.name))
+ continue;
+
+ found = 1;
+ err = configfs_attach_attr(sd, dentry);
+ break;
+ }
+ }
+
+ if (!found) {
+ /*
+ * If it doesn't exist and it isn't a NOT_PINNED item,
+ * it must be negative.
+ */
+ return simple_lookup(dir, dentry, nd);
+ }
+
+ return ERR_PTR(err);
+}
+
+/*
+ * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
+ * attributes and are removed by rmdir(). We recurse, taking i_sem
+ * on all children that are candidates for default detach. If the
+ * result is clean, then configfs_detach_group() will handle dropping
+ * i_sem. If there is an error, the caller will clean up the i_sem
+ * holders via configfs_detach_rollback().
+ */
+static int configfs_detach_prep(struct dentry *dentry)
+{
+ struct configfs_dirent *parent_sd = dentry->d_fsdata;
+ struct configfs_dirent *sd;
+ int ret;
+
+ ret = -EBUSY;
+ if (!list_empty(&parent_sd->s_links))
+ goto out;
+
+ ret = 0;
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (sd->s_type & CONFIGFS_NOT_PINNED)
+ continue;
+ if (sd->s_type & CONFIGFS_USET_DEFAULT) {
+ down(&sd->s_dentry->d_inode->i_sem);
+ /* Mark that we've taken i_sem */
+ sd->s_type |= CONFIGFS_USET_DROPPING;
+
+ ret = configfs_detach_prep(sd->s_dentry);
+ if (!ret)
+ continue;
+ } else
+ ret = -ENOTEMPTY;
+
+ break;
+ }
+
+out:
+ return ret;
+}
+
+/*
+ * Walk the tree, dropping i_sem wherever CONFIGFS_USET_DROPPING is
+ * set.
+ */
+static void configfs_detach_rollback(struct dentry *dentry)
+{
+ struct configfs_dirent *parent_sd = dentry->d_fsdata;
+ struct configfs_dirent *sd;
+
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (sd->s_type & CONFIGFS_USET_DEFAULT) {
+ configfs_detach_rollback(sd->s_dentry);
+
+ if (sd->s_type & CONFIGFS_USET_DROPPING) {
+ sd->s_type &= ~CONFIGFS_USET_DROPPING;
+ up(&sd->s_dentry->d_inode->i_sem);
+ }
+ }
+ }
+}
+
+static void detach_attrs(struct config_item * item)
+{
+ struct dentry * dentry = dget(item->ci_dentry);
+ struct configfs_dirent * parent_sd;
+ struct configfs_dirent * sd, * tmp;
+
+ if (!dentry)
+ return;
+
+ pr_debug("configfs %s: dropping attrs for dir\n",
+ dentry->d_name.name);
+
+ parent_sd = dentry->d_fsdata;
+ list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
+ if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED))
+ continue;
+ list_del_init(&sd->s_sibling);
+ configfs_drop_dentry(sd, dentry);
+ configfs_put(sd);
+ }
+
+ /**
+ * Drop reference from dget() on entrance.
+ */
+ dput(dentry);
+}
+
+static int populate_attrs(struct config_item *item)
+{
+ struct config_item_type *t = item->ci_type;
+ struct configfs_attribute *attr;
+ int error = 0;
+ int i;
+
+ if (!t)
+ return -EINVAL;
+ if (t->ct_attrs) {
+ for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
+ if ((error = configfs_create_file(item, attr)))
+ break;
+ }
+ }
+
+ if (error)
+ detach_attrs(item);
+
+ return error;
+}
+
+static int configfs_attach_group(struct config_item *parent_item,
+ struct config_item *item,
+ struct dentry *dentry);
+static void configfs_detach_group(struct config_item *item);
+
+static void detach_groups(struct config_group *group)
+{
+ struct dentry * dentry = dget(group->cg_item.ci_dentry);
+ struct dentry *child;
+ struct configfs_dirent *parent_sd;
+ struct configfs_dirent *sd, *tmp;
+
+ if (!dentry)
+ return;
+
+ parent_sd = dentry->d_fsdata;
+ list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
+ if (!sd->s_element ||
+ !(sd->s_type & CONFIGFS_USET_DEFAULT))
+ continue;
+
+ child = sd->s_dentry;
+
+ configfs_detach_group(sd->s_element);
+ child->d_inode->i_flags |= S_DEAD;
+
+ /*
+ * From rmdir/unregister, a configfs_detach_prep() pass
+ * has taken our i_sem for us. Drop it.
+ * From mkdir/register cleanup, there is no sem held.
+ */
+ if (sd->s_type & CONFIGFS_USET_DROPPING)
+ up(&child->d_inode->i_sem);
+
+ d_delete(child);
+ dput(child);
+ }
+
+ /**
+ * Drop reference from dget() on entrance.
+ */
+ dput(dentry);
+}
+
+/*
+ * This fakes mkdir(2) on a default_groups[] entry. It
+ * creates a dentry, attachs it, and then does fixup
+ * on the sd->s_type.
+ *
+ * We could, perhaps, tweak our parent's ->mkdir for a minute and
+ * try using vfs_mkdir. Just a thought.
+ */
+static int create_default_group(struct config_group *parent_group,
+ struct config_group *group)
+{
+ int ret;
+ struct qstr name;
+ struct configfs_dirent *sd;
+ /* We trust the caller holds a reference to parent */
+ struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
+
+ if (!group->cg_item.ci_name)
+ group->cg_item.ci_name = group->cg_item.ci_namebuf;
+ name.name = group->cg_item.ci_name;
+ name.len = strlen(name.name);
+ name.hash = full_name_hash(name.name, name.len);
+
+ ret = -ENOMEM;
+ child = d_alloc(parent, &name);
+ if (child) {
+ d_add(child, NULL);
+
+ ret = configfs_attach_group(&parent_group->cg_item,
+ &group->cg_item, child);
+ if (!ret) {
+ sd = child->d_fsdata;
+ sd->s_type |= CONFIGFS_USET_DEFAULT;
+ } else {
+ d_delete(child);
+ dput(child);
+ }
+ }
+
+ return ret;
+}
+
+static int populate_groups(struct config_group *group)
+{
+ struct config_group *new_group;
+ struct dentry *dentry = group->cg_item.ci_dentry;
+ int ret = 0;
+ int i;
+
+ if (group && group->default_groups) {
+ /* FYI, we're faking mkdir here
+ * I'm not sure we need this semaphore, as we're called
+ * from our parent's mkdir. That holds our parent's
+ * i_sem, so afaik lookup cannot continue through our
+ * parent to find us, let alone mess with our tree.
+ * That said, taking our i_sem is closer to mkdir
+ * emulation, and shouldn't hurt. */
+ down(&dentry->d_inode->i_sem);
+
+ for (i = 0; group->default_groups[i]; i++) {
+ new_group = group->default_groups[i];
+
+ ret = create_default_group(group, new_group);
+ if (ret)
+ break;
+ }
+
+ up(&dentry->d_inode->i_sem);
+ }
+
+ if (ret)
+ detach_groups(group);
+
+ return ret;
+}
+
+/*
+ * All of link_obj/unlink_obj/link_group/unlink_group require that
+ * subsys->su_sem is held.
+ */
+
+static void unlink_obj(struct config_item *item)
+{
+ struct config_group *group;
+
+ group = item->ci_group;
+ if (group) {
+ list_del_init(&item->ci_entry);
+
+ item->ci_group = NULL;
+ item->ci_parent = NULL;
+ config_item_put(item);
+
+ config_group_put(group);
+ }
+}
+
+static void link_obj(struct config_item *parent_item, struct config_item *item)
+{
+ /* Parent seems redundant with group, but it makes certain
+ * traversals much nicer. */
+ item->ci_parent = parent_item;
+ item->ci_group = config_group_get(to_config_group(parent_item));
+ list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
+
+ config_item_get(item);
+}
+
+static void unlink_group(struct config_group *group)
+{
+ int i;
+ struct config_group *new_group;
+
+ if (group->default_groups) {
+ for (i = 0; group->default_groups[i]; i++) {
+ new_group = group->default_groups[i];
+ unlink_group(new_group);
+ }
+ }
+
+ group->cg_subsys = NULL;
+ unlink_obj(&group->cg_item);
+}
+
+static void link_group(struct config_group *parent_group, struct config_group *group)
+{
+ int i;
+ struct config_group *new_group;
+ struct configfs_subsystem *subsys = NULL; /* gcc is a turd */
+
+ link_obj(&parent_group->cg_item, &group->cg_item);
+
+ if (parent_group->cg_subsys)
+ subsys = parent_group->cg_subsys;
+ else if (configfs_is_root(&parent_group->cg_item))
+ subsys = to_configfs_subsystem(group);
+ else
+ BUG();
+ group->cg_subsys = subsys;
+
+ if (group->default_groups) {
+ for (i = 0; group->default_groups[i]; i++) {
+ new_group = group->default_groups[i];
+ link_group(group, new_group);
+ }
+ }
+}
+
+/*
+ * The goal is that configfs_attach_item() (and
+ * configfs_attach_group()) can be called from either the VFS or this
+ * module. That is, they assume that the items have been created,
+ * the dentry allocated, and the dcache is all ready to go.
+ *
+ * If they fail, they must clean up after themselves as if they
+ * had never been called. The caller (VFS or local function) will
+ * handle cleaning up the dcache bits.
+ *
+ * configfs_detach_group() and configfs_detach_item() behave similarly on
+ * the way out. They assume that the proper semaphores are held, they
+ * clean up the configfs items, and they expect their callers will
+ * handle the dcache bits.
+ */
+static int configfs_attach_item(struct config_item *parent_item,
+ struct config_item *item,
+ struct dentry *dentry)
+{
+ int ret;
+
+ ret = configfs_create_dir(item, dentry);
+ if (!ret) {
+ ret = populate_attrs(item);
+ if (ret) {
+ configfs_remove_dir(item);
+ d_delete(dentry);
+ }
+ }
+
+ return ret;
+}
+
+static void configfs_detach_item(struct config_item *item)
+{
+ detach_attrs(item);
+ configfs_remove_dir(item);
+}
+
+static int configfs_attach_group(struct config_item *parent_item,
+ struct config_item *item,
+ struct dentry *dentry)
+{
+ int ret;
+ struct configfs_dirent *sd;
+
+ ret = configfs_attach_item(parent_item, item, dentry);
+ if (!ret) {
+ sd = dentry->d_fsdata;
+ sd->s_type |= CONFIGFS_USET_DIR;
+
+ ret = populate_groups(to_config_group(item));
+ if (ret) {
+ configfs_detach_item(item);
+ d_delete(dentry);
+ }
+ }
+
+ return ret;
+}
+
+static void configfs_detach_group(struct config_item *item)
+{
+ detach_groups(to_config_group(item));
+ configfs_detach_item(item);
+}
+
+/*
+ * Drop the initial reference from make_item()/make_group()
+ * This function assumes that reference is held on item
+ * and that item holds a valid reference to the parent. Also, it
+ * assumes the caller has validated ci_type.
+ */
+static void client_drop_item(struct config_item *parent_item,
+ struct config_item *item)
+{
+ struct config_item_type *type;
+
+ type = parent_item->ci_type;
+ BUG_ON(!type);
+
+ if (type->ct_group_ops && type->ct_group_ops->drop_item)
+ type->ct_group_ops->drop_item(to_config_group(parent_item),
+ item);
+ else
+ config_item_put(item);
+}
+
+
+static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ int ret;
+ struct config_group *group;
+ struct config_item *item;
+ struct config_item *parent_item;
+ struct configfs_subsystem *subsys;
+ struct configfs_dirent *sd;
+ struct config_item_type *type;
+ struct module *owner;
+ char *name;
+
+ if (dentry->d_parent == configfs_sb->s_root)
+ return -EPERM;
+
+ sd = dentry->d_parent->d_fsdata;
+ if (!(sd->s_type & CONFIGFS_USET_DIR))
+ return -EPERM;
+
+ parent_item = configfs_get_config_item(dentry->d_parent);
+ type = parent_item->ci_type;
+ subsys = to_config_group(parent_item)->cg_subsys;
+ BUG_ON(!subsys);
+
+ if (!type || !type->ct_group_ops ||
+ (!type->ct_group_ops->make_group &&
+ !type->ct_group_ops->make_item)) {
+ config_item_put(parent_item);
+ return -EPERM; /* What lack-of-mkdir returns */
+ }
+
+ name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
+ if (!name) {
+ config_item_put(parent_item);
+ return -ENOMEM;
+ }
+ snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
+
+ down(&subsys->su_sem);
+ group = NULL;
+ item = NULL;
+ if (type->ct_group_ops->make_group) {
+ group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
+ if (group) {
+ link_group(to_config_group(parent_item), group);
+ item = &group->cg_item;
+ }
+ } else {
+ item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
+ if (item)
+ link_obj(parent_item, item);
+ }
+ up(&subsys->su_sem);
+
+ kfree(name);
+ if (!item) {
+ config_item_put(parent_item);
+ return -ENOMEM;
+ }
+
+ ret = -EINVAL;
+ type = item->ci_type;
+ if (type) {
+ owner = type->ct_owner;
+ if (try_module_get(owner)) {
+ if (group) {
+ ret = configfs_attach_group(parent_item,
+ item,
+ dentry);
+ } else {
+ ret = configfs_attach_item(parent_item,
+ item,
+ dentry);
+ }
+
+ if (ret) {
+ down(&subsys->su_sem);
+ if (group)
+ unlink_group(group);
+ else
+ unlink_obj(item);
+ client_drop_item(parent_item, item);
+ up(&subsys->su_sem);
+
+ config_item_put(parent_item);
+ module_put(owner);
+ }
+ }
+ }
+
+ return ret;
+}
+
+static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct config_item *parent_item;
+ struct config_item *item;
+ struct configfs_subsystem *subsys;
+ struct configfs_dirent *sd;
+ struct module *owner = NULL;
+ int ret;
+
+ if (dentry->d_parent == configfs_sb->s_root)
+ return -EPERM;
+
+ sd = dentry->d_fsdata;
+ if (sd->s_type & CONFIGFS_USET_DEFAULT)
+ return -EPERM;
+
+ parent_item = configfs_get_config_item(dentry->d_parent);
+ subsys = to_config_group(parent_item)->cg_subsys;
+ BUG_ON(!subsys);
+
+ if (!parent_item->ci_type) {
+ config_item_put(parent_item);
+ return -EINVAL;
+ }
+
+ ret = configfs_detach_prep(dentry);
+ if (ret) {
+ configfs_detach_rollback(dentry);
+ config_item_put(parent_item);
+ return ret;
+ }
+
+ item = configfs_get_config_item(dentry);
+
+ /* Drop reference from above, item already holds one. */
+ config_item_put(parent_item);
+
+ if (item->ci_type)
+ owner = item->ci_type->ct_owner;
+
+ if (sd->s_type & CONFIGFS_USET_DIR) {
+ configfs_detach_group(item);
+
+ down(&subsys->su_sem);
+ unlink_group(to_config_group(item));
+ } else {
+ configfs_detach_item(item);
+
+ down(&subsys->su_sem);
+ unlink_obj(item);
+ }
+
+ client_drop_item(parent_item, item);
+ up(&subsys->su_sem);
+
+ /* Drop our reference from above */
+ config_item_put(item);
+
+ module_put(owner);
+
+ return 0;
+}
+
+struct inode_operations configfs_dir_inode_operations = {
+ .mkdir = configfs_mkdir,
+ .rmdir = configfs_rmdir,
+ .symlink = configfs_symlink,
+ .unlink = configfs_unlink,
+ .lookup = configfs_lookup,
+};
+
+#if 0
+int configfs_rename_dir(struct config_item * item, const char *new_name)
+{
+ int error = 0;
+ struct dentry * new_dentry, * parent;
+
+ if (!strcmp(config_item_name(item), new_name))
+ return -EINVAL;
+
+ if (!item->parent)
+ return -EINVAL;
+
+ down_write(&configfs_rename_sem);
+ parent = item->parent->dentry;
+
+ down(&parent->d_inode->i_sem);
+
+ new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
+ if (!IS_ERR(new_dentry)) {
+ if (!new_dentry->d_inode) {
+ error = config_item_set_name(item, "%s", new_name);
+ if (!error) {
+ d_add(new_dentry, NULL);
+ d_move(item->dentry, new_dentry);
+ }
+ else
+ d_delete(new_dentry);
+ } else
+ error = -EEXIST;
+ dput(new_dentry);
+ }
+ up(&parent->d_inode->i_sem);
+ up_write(&configfs_rename_sem);
+
+ return error;
+}
+#endif
+
+static int configfs_dir_open(struct inode *inode, struct file *file)
+{
+ struct dentry * dentry = file->f_dentry;
+ struct configfs_dirent * parent_sd = dentry->d_fsdata;
+
+ down(&dentry->d_inode->i_sem);
+ file->private_data = configfs_new_dirent(parent_sd, NULL);
+ up(&dentry->d_inode->i_sem);
+
+ return file->private_data ? 0 : -ENOMEM;
+
+}
+
+static int configfs_dir_close(struct inode *inode, struct file *file)
+{
+ struct dentry * dentry = file->f_dentry;
+ struct configfs_dirent * cursor = file->private_data;
+
+ down(&dentry->d_inode->i_sem);
+ list_del_init(&cursor->s_sibling);
+ up(&dentry->d_inode->i_sem);
+
+ release_configfs_dirent(cursor);
+
+ return 0;
+}
+
+/* Relationship between s_mode and the DT_xxx types */
+static inline unsigned char dt_type(struct configfs_dirent *sd)
+{
+ return (sd->s_mode >> 12) & 15;
+}
+
+static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+ struct dentry *dentry = filp->f_dentry;
+ struct configfs_dirent * parent_sd = dentry->d_fsdata;
+ struct configfs_dirent *cursor = filp->private_data;
+ struct list_head *p, *q = &cursor->s_sibling;
+ ino_t ino;
+ int i = filp->f_pos;
+
+ switch (i) {
+ case 0:
+ ino = dentry->d_inode->i_ino;
+ if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
+ break;
+ filp->f_pos++;
+ i++;
+ /* fallthrough */
+ case 1:
+ ino = parent_ino(dentry);
+ if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
+ break;
+ filp->f_pos++;
+ i++;
+ /* fallthrough */
+ default:
+ if (filp->f_pos == 2) {
+ list_del(q);
+ list_add(q, &parent_sd->s_children);
+ }
+ for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
+ struct configfs_dirent *next;
+ const char * name;
+ int len;
+
+ next = list_entry(p, struct configfs_dirent,
+ s_sibling);
+ if (!next->s_element)
+ continue;
+
+ name = configfs_get_name(next);
+ len = strlen(name);
+ if (next->s_dentry)
+ ino = next->s_dentry->d_inode->i_ino;
+ else
+ ino = iunique(configfs_sb, 2);
+
+ if (filldir(dirent, name, len, filp->f_pos, ino,
+ dt_type(next)) < 0)
+ return 0;
+
+ list_del(q);
+ list_add(q, p);
+ p = q;
+ filp->f_pos++;
+ }
+ }
+ return 0;
+}
+
+static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
+{
+ struct dentry * dentry = file->f_dentry;
+
+ down(&dentry->d_inode->i_sem);
+ switch (origin) {
+ case 1:
+ offset += file->f_pos;
+ case 0:
+ if (offset >= 0)
+ break;
+ default:
+ up(&file->f_dentry->d_inode->i_sem);
+ return -EINVAL;
+ }
+ if (offset != file->f_pos) {
+ file->f_pos = offset;
+ if (file->f_pos >= 2) {
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_dirent *cursor = file->private_data;
+ struct list_head *p;
+ loff_t n = file->f_pos - 2;
+
+ list_del(&cursor->s_sibling);
+ p = sd->s_children.next;
+ while (n && p != &sd->s_children) {
+ struct configfs_dirent *next;
+ next = list_entry(p, struct configfs_dirent,
+ s_sibling);
+ if (next->s_element)
+ n--;
+ p = p->next;
+ }
+ list_add_tail(&cursor->s_sibling, p);
+ }
+ }
+ up(&dentry->d_inode->i_sem);
+ return offset;
+}
+
+struct file_operations configfs_dir_operations = {
+ .open = configfs_dir_open,
+ .release = configfs_dir_close,
+ .llseek = configfs_dir_lseek,
+ .read = generic_read_dir,
+ .readdir = configfs_readdir,
+};
+
+int configfs_register_subsystem(struct configfs_subsystem *subsys)
+{
+ int err;
+ struct config_group *group = &subsys->su_group;
+ struct qstr name;
+ struct dentry *dentry;
+ struct configfs_dirent *sd;
+
+ err = configfs_pin_fs();
+ if (err)
+ return err;
+
+ if (!group->cg_item.ci_name)
+ group->cg_item.ci_name = group->cg_item.ci_namebuf;
+
+ sd = configfs_sb->s_root->d_fsdata;
+ link_group(to_config_group(sd->s_element), group);
+
+ down(&configfs_sb->s_root->d_inode->i_sem);
+
+ name.name = group->cg_item.ci_name;
+ name.len = strlen(name.name);
+ name.hash = full_name_hash(name.name, name.len);
+
+ err = -ENOMEM;
+ dentry = d_alloc(configfs_sb->s_root, &name);
+ if (!dentry)
+ goto out_release;
+
+ d_add(dentry, NULL);
+
+ err = configfs_attach_group(sd->s_element, &group->cg_item,
+ dentry);
+ if (!err)
+ dentry = NULL;
+ else
+ d_delete(dentry);
+
+ up(&configfs_sb->s_root->d_inode->i_sem);
+
+ if (dentry) {
+ dput(dentry);
+out_release:
+ unlink_group(group);
+ configfs_release_fs();
+ }
+
+ return err;
+}
+
+void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
+{
+ struct config_group *group = &subsys->su_group;
+ struct dentry *dentry = group->cg_item.ci_dentry;
+
+ if (dentry->d_parent != configfs_sb->s_root) {
+ printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
+ return;
+ }
+
+ down(&configfs_sb->s_root->d_inode->i_sem);
+ down(&dentry->d_inode->i_sem);
+ if (configfs_detach_prep(dentry)) {
+ printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
+ }
+ configfs_detach_group(&group->cg_item);
+ dentry->d_inode->i_flags |= S_DEAD;
+ up(&dentry->d_inode->i_sem);
+
+ d_delete(dentry);
+
+ up(&configfs_sb->s_root->d_inode->i_sem);
+
+ dput(dentry);
+
+ unlink_group(group);
+ configfs_release_fs();
+}
+
+EXPORT_SYMBOL(configfs_register_subsystem);
+EXPORT_SYMBOL(configfs_unregister_subsystem);
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * file.c - operations for regular (text) files.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/dnotify.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <asm/semaphore.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+
+struct configfs_buffer {
+ size_t count;
+ loff_t pos;
+ char * page;
+ struct configfs_item_operations * ops;
+ struct semaphore sem;
+ int needs_read_fill;
+};
+
+
+/**
+ * fill_read_buffer - allocate and fill buffer from item.
+ * @dentry: dentry pointer.
+ * @buffer: data buffer for file.
+ *
+ * Allocate @buffer->page, if it hasn't been already, then call the
+ * config_item's show() method to fill the buffer with this attribute's
+ * data.
+ * This is called only once, on the file's first read.
+ */
+static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buffer)
+{
+ struct configfs_attribute * attr = to_attr(dentry);
+ struct config_item * item = to_item(dentry->d_parent);
+ struct configfs_item_operations * ops = buffer->ops;
+ int ret = 0;
+ ssize_t count;
+
+ if (!buffer->page)
+ buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
+ if (!buffer->page)
+ return -ENOMEM;
+
+ count = ops->show_attribute(item,attr,buffer->page);
+ buffer->needs_read_fill = 0;
+ BUG_ON(count > (ssize_t)PAGE_SIZE);
+ if (count >= 0)
+ buffer->count = count;
+ else
+ ret = count;
+ return ret;
+}
+
+
+/**
+ * flush_read_buffer - push buffer to userspace.
+ * @buffer: data buffer for file.
+ * @userbuf: user-passed buffer.
+ * @count: number of bytes requested.
+ * @ppos: file position.
+ *
+ * Copy the buffer we filled in fill_read_buffer() to userspace.
+ * This is done at the reader's leisure, copying and advancing
+ * the amount they specify each time.
+ * This may be called continuously until the buffer is empty.
+ */
+static int flush_read_buffer(struct configfs_buffer * buffer, char __user * buf,
+ size_t count, loff_t * ppos)
+{
+ int error;
+
+ if (*ppos > buffer->count)
+ return 0;
+
+ if (count > (buffer->count - *ppos))
+ count = buffer->count - *ppos;
+
+ error = copy_to_user(buf,buffer->page + *ppos,count);
+ if (!error)
+ *ppos += count;
+ return error ? -EFAULT : count;
+}
+
+/**
+ * configfs_read_file - read an attribute.
+ * @file: file pointer.
+ * @buf: buffer to fill.
+ * @count: number of bytes to read.
+ * @ppos: starting offset in file.
+ *
+ * Userspace wants to read an attribute file. The attribute descriptor
+ * is in the file's ->d_fsdata. The target item is in the directory's
+ * ->d_fsdata.
+ *
+ * We call fill_read_buffer() to allocate and fill the buffer from the
+ * item's show() method exactly once (if the read is happening from
+ * the beginning of the file). That should fill the entire buffer with
+ * all the data the item has to offer for that attribute.
+ * We then call flush_read_buffer() to copy the buffer to userspace
+ * in the increments specified.
+ */
+
+static ssize_t
+configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ struct configfs_buffer * buffer = file->private_data;
+ ssize_t retval = 0;
+
+ down(&buffer->sem);
+ if (buffer->needs_read_fill) {
+ if ((retval = fill_read_buffer(file->f_dentry,buffer)))
+ goto out;
+ }
+ pr_debug("%s: count = %d, ppos = %lld, buf = %s\n",
+ __FUNCTION__,count,*ppos,buffer->page);
+ retval = flush_read_buffer(buffer,buf,count,ppos);
+out:
+ up(&buffer->sem);
+ return retval;
+}
+
+
+/**
+ * fill_write_buffer - copy buffer from userspace.
+ * @buffer: data buffer for file.
+ * @userbuf: data from user.
+ * @count: number of bytes in @userbuf.
+ *
+ * Allocate @buffer->page if it hasn't been already, then
+ * copy the user-supplied buffer into it.
+ */
+
+static int
+fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count)
+{
+ int error;
+
+ if (!buffer->page)
+ buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buffer->page)
+ return -ENOMEM;
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+ error = copy_from_user(buffer->page,buf,count);
+ buffer->needs_read_fill = 1;
+ return error ? -EFAULT : count;
+}
+
+
+/**
+ * flush_write_buffer - push buffer to config_item.
+ * @file: file pointer.
+ * @buffer: data buffer for file.
+ *
+ * Get the correct pointers for the config_item and the attribute we're
+ * dealing with, then call the store() method for the attribute,
+ * passing the buffer that we acquired in fill_write_buffer().
+ */
+
+static int
+flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size_t count)
+{
+ struct configfs_attribute * attr = to_attr(dentry);
+ struct config_item * item = to_item(dentry->d_parent);
+ struct configfs_item_operations * ops = buffer->ops;
+
+ return ops->store_attribute(item,attr,buffer->page,count);
+}
+
+
+/**
+ * configfs_write_file - write an attribute.
+ * @file: file pointer
+ * @buf: data to write
+ * @count: number of bytes
+ * @ppos: starting offset
+ *
+ * Similar to configfs_read_file(), though working in the opposite direction.
+ * We allocate and fill the data from the user in fill_write_buffer(),
+ * then push it to the config_item in flush_write_buffer().
+ * There is no easy way for us to know if userspace is only doing a partial
+ * write, so we don't support them. We expect the entire buffer to come
+ * on the first write.
+ * Hint: if you're writing a value, first read the file, modify only the
+ * the value you're changing, then write entire buffer back.
+ */
+
+static ssize_t
+configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct configfs_buffer * buffer = file->private_data;
+
+ down(&buffer->sem);
+ count = fill_write_buffer(buffer,buf,count);
+ if (count > 0)
+ count = flush_write_buffer(file->f_dentry,buffer,count);
+ if (count > 0)
+ *ppos += count;
+ up(&buffer->sem);
+ return count;
+}
+
+static int check_perm(struct inode * inode, struct file * file)
+{
+ struct config_item *item = configfs_get_config_item(file->f_dentry->d_parent);
+ struct configfs_attribute * attr = to_attr(file->f_dentry);
+ struct configfs_buffer * buffer;
+ struct configfs_item_operations * ops = NULL;
+ int error = 0;
+
+ if (!item || !attr)
+ goto Einval;
+
+ /* Grab the module reference for this attribute if we have one */
+ if (!try_module_get(attr->ca_owner)) {
+ error = -ENODEV;
+ goto Done;
+ }
+
+ if (item->ci_type)
+ ops = item->ci_type->ct_item_ops;
+ else
+ goto Eaccess;
+
+ /* File needs write support.
+ * The inode's perms must say it's ok,
+ * and we must have a store method.
+ */
+ if (file->f_mode & FMODE_WRITE) {
+
+ if (!(inode->i_mode & S_IWUGO) || !ops->store_attribute)
+ goto Eaccess;
+
+ }
+
+ /* File needs read support.
+ * The inode's perms must say it's ok, and we there
+ * must be a show method for it.
+ */
+ if (file->f_mode & FMODE_READ) {
+ if (!(inode->i_mode & S_IRUGO) || !ops->show_attribute)
+ goto Eaccess;
+ }
+
+ /* No error? Great, allocate a buffer for the file, and store it
+ * it in file->private_data for easy access.
+ */
+ buffer = kmalloc(sizeof(struct configfs_buffer),GFP_KERNEL);
+ if (buffer) {
+ memset(buffer,0,sizeof(struct configfs_buffer));
+ init_MUTEX(&buffer->sem);
+ buffer->needs_read_fill = 1;
+ buffer->ops = ops;
+ file->private_data = buffer;
+ } else
+ error = -ENOMEM;
+ goto Done;
+
+ Einval:
+ error = -EINVAL;
+ goto Done;
+ Eaccess:
+ error = -EACCES;
+ module_put(attr->ca_owner);
+ Done:
+ if (error && item)
+ config_item_put(item);
+ return error;
+}
+
+static int configfs_open_file(struct inode * inode, struct file * filp)
+{
+ return check_perm(inode,filp);
+}
+
+static int configfs_release(struct inode * inode, struct file * filp)
+{
+ struct config_item * item = to_item(filp->f_dentry->d_parent);
+ struct configfs_attribute * attr = to_attr(filp->f_dentry);
+ struct module * owner = attr->ca_owner;
+ struct configfs_buffer * buffer = filp->private_data;
+
+ if (item)
+ config_item_put(item);
+ /* After this point, attr should not be accessed. */
+ module_put(owner);
+
+ if (buffer) {
+ if (buffer->page)
+ free_page((unsigned long)buffer->page);
+ kfree(buffer);
+ }
+ return 0;
+}
+
+struct file_operations configfs_file_operations = {
+ .read = configfs_read_file,
+ .write = configfs_write_file,
+ .llseek = generic_file_llseek,
+ .open = configfs_open_file,
+ .release = configfs_release,
+};
+
+
+int configfs_add_file(struct dentry * dir, const struct configfs_attribute * attr, int type)
+{
+ struct configfs_dirent * parent_sd = dir->d_fsdata;
+ umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG;
+ int error = 0;
+
+ down(&dir->d_inode->i_sem);
+ error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, type);
+ up(&dir->d_inode->i_sem);
+
+ return error;
+}
+
+
+/**
+ * configfs_create_file - create an attribute file for an item.
+ * @item: item we're creating for.
+ * @attr: atrribute descriptor.
+ */
+
+int configfs_create_file(struct config_item * item, const struct configfs_attribute * attr)
+{
+ BUG_ON(!item || !item->ci_dentry || !attr);
+
+ return configfs_add_file(item->ci_dentry, attr,
+ CONFIGFS_ITEM_ATTR);
+}
+
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * inode.c - basic inode and dentry operations.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ *
+ * Please see Documentation/filesystems/configfs.txt for more information.
+ */
+
+#undef DEBUG
+
+#include <linux/pagemap.h>
+#include <linux/namei.h>
+#include <linux/backing-dev.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+extern struct super_block * configfs_sb;
+
+static struct address_space_operations configfs_aops = {
+ .readpage = simple_readpage,
+ .prepare_write = simple_prepare_write,
+ .commit_write = simple_commit_write
+};
+
+static struct backing_dev_info configfs_backing_dev_info = {
+ .ra_pages = 0, /* No readahead */
+ .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+};
+
+struct inode * configfs_new_inode(mode_t mode)
+{
+ struct inode * inode = new_inode(configfs_sb);
+ if (inode) {
+ inode->i_mode = mode;
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_mapping->a_ops = &configfs_aops;
+ inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
+ }
+ return inode;
+}
+
+int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
+{
+ int error = 0;
+ struct inode * inode = NULL;
+ if (dentry) {
+ if (!dentry->d_inode) {
+ if ((inode = configfs_new_inode(mode))) {
+ if (dentry->d_parent && dentry->d_parent->d_inode) {
+ struct inode *p_inode = dentry->d_parent->d_inode;
+ p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
+ }
+ goto Proceed;
+ }
+ else
+ error = -ENOMEM;
+ } else
+ error = -EEXIST;
+ } else
+ error = -ENOENT;
+ goto Done;
+
+ Proceed:
+ if (init)
+ error = init(inode);
+ if (!error) {
+ d_instantiate(dentry, inode);
+ if (S_ISDIR(mode) || S_ISLNK(mode))
+ dget(dentry); /* pin link and directory dentries in core */
+ } else
+ iput(inode);
+ Done:
+ return error;
+}
+
+/*
+ * Get the name for corresponding element represented by the given configfs_dirent
+ */
+const unsigned char * configfs_get_name(struct configfs_dirent *sd)
+{
+ struct attribute * attr;
+
+ if (!sd || !sd->s_element)
+ BUG();
+
+ /* These always have a dentry, so use that */
+ if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
+ return sd->s_dentry->d_name.name;
+
+ if (sd->s_type & CONFIGFS_ITEM_ATTR) {
+ attr = sd->s_element;
+ return attr->name;
+ }
+ return NULL;
+}
+
+
+/*
+ * Unhashes the dentry corresponding to given configfs_dirent
+ * Called with parent inode's i_sem held.
+ */
+void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
+{
+ struct dentry * dentry = sd->s_dentry;
+
+ if (dentry) {
+ spin_lock(&dcache_lock);
+ if (!(d_unhashed(dentry) && dentry->d_inode)) {
+ dget_locked(dentry);
+ __d_drop(dentry);
+ spin_unlock(&dcache_lock);
+ simple_unlink(parent->d_inode, dentry);
+ } else
+ spin_unlock(&dcache_lock);
+ }
+}
+
+void configfs_hash_and_remove(struct dentry * dir, const char * name)
+{
+ struct configfs_dirent * sd;
+ struct configfs_dirent * parent_sd = dir->d_fsdata;
+
+ down(&dir->d_inode->i_sem);
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (!sd->s_element)
+ continue;
+ if (!strcmp(configfs_get_name(sd), name)) {
+ list_del_init(&sd->s_sibling);
+ configfs_drop_dentry(sd, dir);
+ configfs_put(sd);
+ break;
+ }
+ }
+ up(&dir->d_inode->i_sem);
+}
+
+
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * item.c - library routines for handling generic config items
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on kobject:
+ * kobject is Copyright (c) 2002-2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ *
+ * Please see the file Documentation/filesystems/configfs.txt for
+ * critical information about using the config_item interface.
+ */
+
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+
+
+static inline struct config_item * to_item(struct list_head * entry)
+{
+ return container_of(entry,struct config_item,ci_entry);
+}
+
+/* Evil kernel */
+static void config_item_release(struct kref *kref);
+
+/**
+ * config_item_init - initialize item.
+ * @item: item in question.
+ */
+void config_item_init(struct config_item * item)
+{
+ kref_init(&item->ci_kref);
+ INIT_LIST_HEAD(&item->ci_entry);
+}
+
+/**
+ * config_item_set_name - Set the name of an item
+ * @item: item.
+ * @name: name.
+ *
+ * If strlen(name) >= CONFIGFS_ITEM_NAME_LEN, then use a
+ * dynamically allocated string that @item->ci_name points to.
+ * Otherwise, use the static @item->ci_namebuf array.
+ */
+
+int config_item_set_name(struct config_item * item, const char * fmt, ...)
+{
+ int error = 0;
+ int limit = CONFIGFS_ITEM_NAME_LEN;
+ int need;
+ va_list args;
+ char * name;
+
+ /*
+ * First, try the static array
+ */
+ va_start(args,fmt);
+ need = vsnprintf(item->ci_namebuf,limit,fmt,args);
+ va_end(args);
+ if (need < limit)
+ name = item->ci_namebuf;
+ else {
+ /*
+ * Need more space? Allocate it and try again
+ */
+ limit = need + 1;
+ name = kmalloc(limit,GFP_KERNEL);
+ if (!name) {
+ error = -ENOMEM;
+ goto Done;
+ }
+ va_start(args,fmt);
+ need = vsnprintf(name,limit,fmt,args);
+ va_end(args);
+
+ /* Still? Give up. */
+ if (need >= limit) {
+ kfree(name);
+ error = -EFAULT;
+ goto Done;
+ }
+ }
+
+ /* Free the old name, if necessary. */
+ if (item->ci_name && item->ci_name != item->ci_namebuf)
+ kfree(item->ci_name);
+
+ /* Now, set the new name */
+ item->ci_name = name;
+ Done:
+ return error;
+}
+
+EXPORT_SYMBOL(config_item_set_name);
+
+void config_item_init_type_name(struct config_item *item,
+ const char *name,
+ struct config_item_type *type)
+{
+ config_item_set_name(item, name);
+ item->ci_type = type;
+ config_item_init(item);
+}
+EXPORT_SYMBOL(config_item_init_type_name);
+
+void config_group_init_type_name(struct config_group *group, const char *name,
+ struct config_item_type *type)
+{
+ config_item_set_name(&group->cg_item, name);
+ group->cg_item.ci_type = type;
+ config_group_init(group);
+}
+EXPORT_SYMBOL(config_group_init_type_name);
+
+struct config_item * config_item_get(struct config_item * item)
+{
+ if (item)
+ kref_get(&item->ci_kref);
+ return item;
+}
+
+/**
+ * config_item_cleanup - free config_item resources.
+ * @item: item.
+ */
+
+void config_item_cleanup(struct config_item * item)
+{
+ struct config_item_type * t = item->ci_type;
+ struct config_group * s = item->ci_group;
+ struct config_item * parent = item->ci_parent;
+
+ pr_debug("config_item %s: cleaning up\n",config_item_name(item));
+ if (item->ci_name != item->ci_namebuf)
+ kfree(item->ci_name);
+ item->ci_name = NULL;
+ if (t && t->ct_item_ops && t->ct_item_ops->release)
+ t->ct_item_ops->release(item);
+ if (s)
+ config_group_put(s);
+ if (parent)
+ config_item_put(parent);
+}
+
+static void config_item_release(struct kref *kref)
+{
+ config_item_cleanup(container_of(kref, struct config_item, ci_kref));
+}
+
+/**
+ * config_item_put - decrement refcount for item.
+ * @item: item.
+ *
+ * Decrement the refcount, and if 0, call config_item_cleanup().
+ */
+void config_item_put(struct config_item * item)
+{
+ if (item)
+ kref_put(&item->ci_kref, config_item_release);
+}
+
+
+/**
+ * config_group_init - initialize a group for use
+ * @k: group
+ */
+
+void config_group_init(struct config_group *group)
+{
+ config_item_init(&group->cg_item);
+ INIT_LIST_HEAD(&group->cg_children);
+}
+
+
+/**
+ * config_group_find_obj - search for item in group.
+ * @group: group we're looking in.
+ * @name: item's name.
+ *
+ * Lock group via @group->cg_subsys, and iterate over @group->cg_list,
+ * looking for a matching config_item. If matching item is found
+ * take a reference and return the item.
+ */
+
+struct config_item * config_group_find_obj(struct config_group * group, const char * name)
+{
+ struct list_head * entry;
+ struct config_item * ret = NULL;
+
+ /* XXX LOCKING! */
+ list_for_each(entry,&group->cg_children) {
+ struct config_item * item = to_item(entry);
+ if (config_item_name(item) &&
+ !strcmp(config_item_name(item), name)) {
+ ret = config_item_get(item);
+ break;
+ }
+ }
+ return ret;
+}
+
+
+EXPORT_SYMBOL(config_item_init);
+EXPORT_SYMBOL(config_group_init);
+EXPORT_SYMBOL(config_item_get);
+EXPORT_SYMBOL(config_item_put);
+
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * mount.c - operations for initializing and mounting configfs.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+/* Random magic number */
+#define CONFIGFS_MAGIC 0x62656570
+
+struct vfsmount * configfs_mount = NULL;
+struct super_block * configfs_sb = NULL;
+static int configfs_mnt_count = 0;
+
+static struct super_operations configfs_ops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+};
+
+static struct config_group configfs_root_group = {
+ .cg_item = {
+ .ci_namebuf = "root",
+ .ci_name = configfs_root_group.cg_item.ci_namebuf,
+ },
+};
+
+int configfs_is_root(struct config_item *item)
+{
+ return item == &configfs_root_group.cg_item;
+}
+
+static struct configfs_dirent configfs_root = {
+ .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
+ .s_children = LIST_HEAD_INIT(configfs_root.s_children),
+ .s_element = &configfs_root_group.cg_item,
+ .s_type = CONFIGFS_ROOT,
+};
+
+static int configfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+ struct dentry *root;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = CONFIGFS_MAGIC;
+ sb->s_op = &configfs_ops;
+ configfs_sb = sb;
+
+ inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
+ if (inode) {
+ inode->i_op = &configfs_dir_inode_operations;
+ inode->i_fop = &configfs_dir_operations;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inode->i_nlink++;
+ } else {
+ pr_debug("configfs: could not get root inode\n");
+ return -ENOMEM;
+ }
+
+ root = d_alloc_root(inode);
+ if (!root) {
+ pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
+ iput(inode);
+ return -ENOMEM;
+ }
+ config_group_init(&configfs_root_group);
+ configfs_root_group.cg_item.ci_dentry = root;
+ root->d_fsdata = &configfs_root;
+ sb->s_root = root;
+ return 0;
+}
+
+static struct super_block *configfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return get_sb_single(fs_type, flags, data, configfs_fill_super);
+}
+
+static struct file_system_type configfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "configfs",
+ .get_sb = configfs_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+int configfs_pin_fs(void)
+{
+ return simple_pin_fs("configfs", &configfs_mount,
+ &configfs_mnt_count);
+}
+
+void configfs_release_fs(void)
+{
+ simple_release_fs(&configfs_mount, &configfs_mnt_count);
+}
+
+
+static decl_subsys(config, NULL, NULL);
+
+static int __init configfs_init(void)
+{
+ int err;
+
+ kset_set_kset_s(&config_subsys, kernel_subsys);
+ err = subsystem_register(&config_subsys);
+ if (err)
+ return err;
+
+ err = register_filesystem(&configfs_fs_type);
+ if (err) {
+ printk(KERN_ERR "configfs: Unable to register filesystem!\n");
+ subsystem_unregister(&config_subsys);
+ }
+
+ return err;
+}
+
+static void __exit configfs_exit(void)
+{
+ unregister_filesystem(&configfs_fs_type);
+ subsystem_unregister(&config_subsys);
+}
+
+MODULE_AUTHOR("Oracle");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.0.1");
+MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
+
+module_init(configfs_init);
+module_exit(configfs_exit);
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * symlink.c - operations for configfs symlinks.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/namei.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+static int item_depth(struct config_item * item)
+{
+ struct config_item * p = item;
+ int depth = 0;
+ do { depth++; } while ((p = p->ci_parent) && !configfs_is_root(p));
+ return depth;
+}
+
+static int item_path_length(struct config_item * item)
+{
+ struct config_item * p = item;
+ int length = 1;
+ do {
+ length += strlen(config_item_name(p)) + 1;
+ p = p->ci_parent;
+ } while (p && !configfs_is_root(p));
+ return length;
+}
+
+static void fill_item_path(struct config_item * item, char * buffer, int length)
+{
+ struct config_item * p;
+
+ --length;
+ for (p = item; p && !configfs_is_root(p); p = p->ci_parent) {
+ int cur = strlen(config_item_name(p));
+
+ /* back up enough to print this bus id with '/' */
+ length -= cur;
+ strncpy(buffer + length,config_item_name(p),cur);
+ *(buffer + --length) = '/';
+ }
+}
+
+static int create_link(struct config_item *parent_item,
+ struct config_item *item,
+ struct dentry *dentry)
+{
+ struct configfs_dirent *target_sd = item->ci_dentry->d_fsdata;
+ struct configfs_symlink *sl;
+ int ret;
+
+ ret = -ENOMEM;
+ sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL);
+ if (sl) {
+ sl->sl_target = config_item_get(item);
+ /* FIXME: needs a lock, I'd bet */
+ list_add(&sl->sl_list, &target_sd->s_links);
+ ret = configfs_create_link(sl, parent_item->ci_dentry,
+ dentry);
+ if (ret) {
+ list_del_init(&sl->sl_list);
+ config_item_put(item);
+ kfree(sl);
+ }
+ }
+
+ return ret;
+}
+
+
+static int get_target(const char *symname, struct nameidata *nd,
+ struct config_item **target)
+{
+ int ret;
+
+ ret = path_lookup(symname, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, nd);
+ if (!ret) {
+ if (nd->dentry->d_sb == configfs_sb) {
+ *target = configfs_get_config_item(nd->dentry);
+ if (!*target) {
+ ret = -ENOENT;
+ path_release(nd);
+ }
+ } else
+ ret = -EPERM;
+ }
+
+ return ret;
+}
+
+
+int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ int ret;
+ struct nameidata nd;
+ struct config_item *parent_item;
+ struct config_item *target_item;
+ struct config_item_type *type;
+
+ ret = -EPERM; /* What lack-of-symlink returns */
+ if (dentry->d_parent == configfs_sb->s_root)
+ goto out;
+
+ parent_item = configfs_get_config_item(dentry->d_parent);
+ type = parent_item->ci_type;
+
+ if (!type || !type->ct_item_ops ||
+ !type->ct_item_ops->allow_link)
+ goto out_put;
+
+ ret = get_target(symname, &nd, &target_item);
+ if (ret)
+ goto out_put;
+
+ ret = type->ct_item_ops->allow_link(parent_item, target_item);
+ if (!ret)
+ ret = create_link(parent_item, target_item, dentry);
+
+ config_item_put(target_item);
+ path_release(&nd);
+
+out_put:
+ config_item_put(parent_item);
+
+out:
+ return ret;
+}
+
+int configfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_symlink *sl;
+ struct config_item *parent_item;
+ struct config_item_type *type;
+ int ret;
+
+ ret = -EPERM; /* What lack-of-symlink returns */
+ if (!(sd->s_type & CONFIGFS_ITEM_LINK))
+ goto out;
+
+ if (dentry->d_parent == configfs_sb->s_root)
+ BUG();
+
+ sl = sd->s_element;
+
+ parent_item = configfs_get_config_item(dentry->d_parent);
+ type = parent_item->ci_type;
+
+ list_del_init(&sd->s_sibling);
+ configfs_drop_dentry(sd, dentry->d_parent);
+ dput(dentry);
+ configfs_put(sd);
+
+ /*
+ * drop_link() must be called before
+ * list_del_init(&sl->sl_list), so that the order of
+ * drop_link(this, target) and drop_item(target) is preserved.
+ */
+ if (type && type->ct_item_ops &&
+ type->ct_item_ops->drop_link)
+ type->ct_item_ops->drop_link(parent_item,
+ sl->sl_target);
+
+ /* FIXME: Needs lock */
+ list_del_init(&sl->sl_list);
+
+ /* Put reference from create_link() */
+ config_item_put(sl->sl_target);
+ kfree(sl);
+
+ config_item_put(parent_item);
+
+ ret = 0;
+
+out:
+ return ret;
+}
+
+static int configfs_get_target_path(struct config_item * item, struct config_item * target,
+ char *path)
+{
+ char * s;
+ int depth, size;
+
+ depth = item_depth(item);
+ size = item_path_length(target) + depth * 3 - 1;
+ if (size > PATH_MAX)
+ return -ENAMETOOLONG;
+
+ pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
+
+ for (s = path; depth--; s += 3)
+ strcpy(s,"../");
+
+ fill_item_path(target, path, size);
+ pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
+
+ return 0;
+}
+
+static int configfs_getlink(struct dentry *dentry, char * path)
+{
+ struct config_item *item, *target_item;
+ int error = 0;
+
+ item = configfs_get_config_item(dentry->d_parent);
+ if (!item)
+ return -EINVAL;
+
+ target_item = configfs_get_config_item(dentry);
+ if (!target_item) {
+ config_item_put(item);
+ return -EINVAL;
+ }
+
+ down_read(&configfs_rename_sem);
+ error = configfs_get_target_path(item, target_item, path);
+ up_read(&configfs_rename_sem);
+
+ config_item_put(item);
+ config_item_put(target_item);
+ return error;
+
+}
+
+static void *configfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ int error = -ENOMEM;
+ unsigned long page = get_zeroed_page(GFP_KERNEL);
+
+ if (page) {
+ error = configfs_getlink(dentry, (char *)page);
+ if (!error) {
+ nd_set_link(nd, (char *)page);
+ return (void *)page;
+ }
+ }
+
+ nd_set_link(nd, ERR_PTR(error));
+ return NULL;
+}
+
+static void configfs_put_link(struct dentry *dentry, struct nameidata *nd,
+ void *cookie)
+{
+ if (cookie) {
+ unsigned long page = (unsigned long)cookie;
+ free_page(page);
+ }
+}
+
+struct inode_operations configfs_symlink_inode_operations = {
+ .follow_link = configfs_follow_link,
+ .readlink = generic_readlink,
+ .put_link = configfs_put_link,
+};
+
&last_block_in_bio, &ret, wbc,
page->mapping->a_ops->writepage);
}
- if (unlikely(ret == WRITEPAGE_ACTIVATE))
+ if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE))
unlock_page(page);
if (ret || (--(wbc->nr_to_write) <= 0))
done = 1;
--- /dev/null
+EXTRA_CFLAGS += -Ifs/ocfs2
+
+EXTRA_CFLAGS += -DCATCH_BH_JBD_RACES
+
+obj-$(CONFIG_OCFS2_FS) += ocfs2.o
+
+ocfs2-objs := \
+ alloc.o \
+ aops.o \
+ buffer_head_io.o \
+ dcache.o \
+ dir.o \
+ dlmglue.o \
+ export.o \
+ extent_map.o \
+ file.o \
+ heartbeat.o \
+ inode.o \
+ journal.o \
+ localalloc.o \
+ mmap.o \
+ namei.o \
+ slot_map.o \
+ suballoc.o \
+ super.o \
+ symlink.o \
+ sysfile.o \
+ uptodate.o \
+ ver.o \
+ vote.o
+
+obj-$(CONFIG_OCFS2_FS) += cluster/
+obj-$(CONFIG_OCFS2_FS) += dlm/
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * alloc.c
+ *
+ * Extent allocs and frees
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+
+#define MLOG_MASK_PREFIX ML_DISK_ALLOC
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "inode.h"
+#include "journal.h"
+#include "localalloc.h"
+#include "suballoc.h"
+#include "sysfile.h"
+#include "file.h"
+#include "super.h"
+#include "uptodate.h"
+
+#include "buffer_head_io.h"
+
+static int ocfs2_extent_contig(struct inode *inode,
+ struct ocfs2_extent_rec *ext,
+ u64 blkno);
+
+static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ int wanted,
+ struct ocfs2_alloc_context *meta_ac,
+ struct buffer_head *bhs[]);
+
+static int ocfs2_add_branch(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct buffer_head *eb_bh,
+ struct buffer_head *last_eb_bh,
+ struct ocfs2_alloc_context *meta_ac);
+
+static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_alloc_context *meta_ac,
+ struct buffer_head **ret_new_eb_bh);
+
+static int ocfs2_do_insert_extent(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ u64 blkno,
+ u32 new_clusters);
+
+static int ocfs2_find_branch_target(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct buffer_head **target_bh);
+
+static int ocfs2_find_new_last_ext_blk(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct ocfs2_dinode *fe,
+ unsigned int new_i_clusters,
+ struct buffer_head *old_last_eb,
+ struct buffer_head **new_last_eb);
+
+static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc);
+
+static int ocfs2_extent_contig(struct inode *inode,
+ struct ocfs2_extent_rec *ext,
+ u64 blkno)
+{
+ return blkno == (le64_to_cpu(ext->e_blkno) +
+ ocfs2_clusters_to_blocks(inode->i_sb,
+ le32_to_cpu(ext->e_clusters)));
+}
+
+/*
+ * How many free extents have we got before we need more meta data?
+ */
+int ocfs2_num_free_extents(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct ocfs2_dinode *fe)
+{
+ int retval;
+ struct ocfs2_extent_list *el;
+ struct ocfs2_extent_block *eb;
+ struct buffer_head *eb_bh = NULL;
+
+ mlog_entry_void();
+
+ if (!OCFS2_IS_VALID_DINODE(fe)) {
+ OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
+ retval = -EIO;
+ goto bail;
+ }
+
+ if (fe->i_last_eb_blk) {
+ retval = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
+ &eb_bh, OCFS2_BH_CACHED, inode);
+ if (retval < 0) {
+ mlog_errno(retval);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) eb_bh->b_data;
+ el = &eb->h_list;
+ } else
+ el = &fe->id2.i_list;
+
+ BUG_ON(el->l_tree_depth != 0);
+
+ retval = le16_to_cpu(el->l_count) - le16_to_cpu(el->l_next_free_rec);
+bail:
+ if (eb_bh)
+ brelse(eb_bh);
+
+ mlog_exit(retval);
+ return retval;
+}
+
+/* expects array to already be allocated
+ *
+ * sets h_signature, h_blkno, h_suballoc_bit, h_suballoc_slot, and
+ * l_count for you
+ */
+static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ int wanted,
+ struct ocfs2_alloc_context *meta_ac,
+ struct buffer_head *bhs[])
+{
+ int count, status, i;
+ u16 suballoc_bit_start;
+ u32 num_got;
+ u64 first_blkno;
+ struct ocfs2_extent_block *eb;
+
+ mlog_entry_void();
+
+ count = 0;
+ while (count < wanted) {
+ status = ocfs2_claim_metadata(osb,
+ handle,
+ meta_ac,
+ wanted - count,
+ &suballoc_bit_start,
+ &num_got,
+ &first_blkno);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ for(i = count; i < (num_got + count); i++) {
+ bhs[i] = sb_getblk(osb->sb, first_blkno);
+ if (bhs[i] == NULL) {
+ status = -EIO;
+ mlog_errno(status);
+ goto bail;
+ }
+ ocfs2_set_new_buffer_uptodate(inode, bhs[i]);
+
+ status = ocfs2_journal_access(handle, inode, bhs[i],
+ OCFS2_JOURNAL_ACCESS_CREATE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ memset(bhs[i]->b_data, 0, osb->sb->s_blocksize);
+ eb = (struct ocfs2_extent_block *) bhs[i]->b_data;
+ /* Ok, setup the minimal stuff here. */
+ strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
+ eb->h_blkno = cpu_to_le64(first_blkno);
+ eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
+
+#ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
+ /* we always use slot zero's suballocator */
+ eb->h_suballoc_slot = 0;
+#else
+ eb->h_suballoc_slot = cpu_to_le16(osb->slot_num);
+#endif
+ eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
+ eb->h_list.l_count =
+ cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
+
+ suballoc_bit_start++;
+ first_blkno++;
+
+ /* We'll also be dirtied by the caller, so
+ * this isn't absolutely necessary. */
+ status = ocfs2_journal_dirty(handle, bhs[i]);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+ count += num_got;
+ }
+
+ status = 0;
+bail:
+ if (status < 0) {
+ for(i = 0; i < wanted; i++) {
+ if (bhs[i])
+ brelse(bhs[i]);
+ bhs[i] = NULL;
+ }
+ }
+ mlog_exit(status);
+ return status;
+}
+
+/*
+ * Add an entire tree branch to our inode. eb_bh is the extent block
+ * to start at, if we don't want to start the branch at the dinode
+ * structure.
+ *
+ * last_eb_bh is required as we have to update it's next_leaf pointer
+ * for the new last extent block.
+ *
+ * the new branch will be 'empty' in the sense that every block will
+ * contain a single record with e_clusters == 0.
+ */
+static int ocfs2_add_branch(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct buffer_head *eb_bh,
+ struct buffer_head *last_eb_bh,
+ struct ocfs2_alloc_context *meta_ac)
+{
+ int status, new_blocks, i;
+ u64 next_blkno, new_last_eb_blk;
+ struct buffer_head *bh;
+ struct buffer_head **new_eb_bhs = NULL;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *eb_el;
+ struct ocfs2_extent_list *el;
+
+ mlog_entry_void();
+
+ BUG_ON(!last_eb_bh);
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+
+ if (eb_bh) {
+ eb = (struct ocfs2_extent_block *) eb_bh->b_data;
+ el = &eb->h_list;
+ } else
+ el = &fe->id2.i_list;
+
+ /* we never add a branch to a leaf. */
+ BUG_ON(!el->l_tree_depth);
+
+ new_blocks = le16_to_cpu(el->l_tree_depth);
+
+ /* allocate the number of new eb blocks we need */
+ new_eb_bhs = kcalloc(new_blocks, sizeof(struct buffer_head *),
+ GFP_KERNEL);
+ if (!new_eb_bhs) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = ocfs2_create_new_meta_bhs(osb, handle, inode, new_blocks,
+ meta_ac, new_eb_bhs);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* Note: new_eb_bhs[new_blocks - 1] is the guy which will be
+ * linked with the rest of the tree.
+ * conversly, new_eb_bhs[0] is the new bottommost leaf.
+ *
+ * when we leave the loop, new_last_eb_blk will point to the
+ * newest leaf, and next_blkno will point to the topmost extent
+ * block. */
+ next_blkno = new_last_eb_blk = 0;
+ for(i = 0; i < new_blocks; i++) {
+ bh = new_eb_bhs[i];
+ eb = (struct ocfs2_extent_block *) bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+ eb_el = &eb->h_list;
+
+ status = ocfs2_journal_access(handle, inode, bh,
+ OCFS2_JOURNAL_ACCESS_CREATE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ eb->h_next_leaf_blk = 0;
+ eb_el->l_tree_depth = cpu_to_le16(i);
+ eb_el->l_next_free_rec = cpu_to_le16(1);
+ eb_el->l_recs[0].e_cpos = fe->i_clusters;
+ eb_el->l_recs[0].e_blkno = cpu_to_le64(next_blkno);
+ eb_el->l_recs[0].e_clusters = cpu_to_le32(0);
+ if (!eb_el->l_tree_depth)
+ new_last_eb_blk = le64_to_cpu(eb->h_blkno);
+
+ status = ocfs2_journal_dirty(handle, bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ next_blkno = le64_to_cpu(eb->h_blkno);
+ }
+
+ /* This is a bit hairy. We want to update up to three blocks
+ * here without leaving any of them in an inconsistent state
+ * in case of error. We don't have to worry about
+ * journal_dirty erroring as it won't unless we've aborted the
+ * handle (in which case we would never be here) so reserving
+ * the write with journal_access is all we need to do. */
+ status = ocfs2_journal_access(handle, inode, last_eb_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ status = ocfs2_journal_access(handle, inode, fe_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ if (eb_bh) {
+ status = ocfs2_journal_access(handle, inode, eb_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+ /* Link the new branch into the rest of the tree (el will
+ * either be on the fe, or the extent block passed in. */
+ i = le16_to_cpu(el->l_next_free_rec);
+ el->l_recs[i].e_blkno = cpu_to_le64(next_blkno);
+ el->l_recs[i].e_cpos = fe->i_clusters;
+ el->l_recs[i].e_clusters = 0;
+ le16_add_cpu(&el->l_next_free_rec, 1);
+
+ /* fe needs a new last extent block pointer, as does the
+ * next_leaf on the previously last-extent-block. */
+ fe->i_last_eb_blk = cpu_to_le64(new_last_eb_blk);
+
+ eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+ eb->h_next_leaf_blk = cpu_to_le64(new_last_eb_blk);
+
+ status = ocfs2_journal_dirty(handle, last_eb_bh);
+ if (status < 0)
+ mlog_errno(status);
+ status = ocfs2_journal_dirty(handle, fe_bh);
+ if (status < 0)
+ mlog_errno(status);
+ if (eb_bh) {
+ status = ocfs2_journal_dirty(handle, eb_bh);
+ if (status < 0)
+ mlog_errno(status);
+ }
+
+ status = 0;
+bail:
+ if (new_eb_bhs) {
+ for (i = 0; i < new_blocks; i++)
+ if (new_eb_bhs[i])
+ brelse(new_eb_bhs[i]);
+ kfree(new_eb_bhs);
+ }
+
+ mlog_exit(status);
+ return status;
+}
+
+/*
+ * adds another level to the allocation tree.
+ * returns back the new extent block so you can add a branch to it
+ * after this call.
+ */
+static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_alloc_context *meta_ac,
+ struct buffer_head **ret_new_eb_bh)
+{
+ int status, i;
+ struct buffer_head *new_eb_bh = NULL;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *fe_el;
+ struct ocfs2_extent_list *eb_el;
+
+ mlog_entry_void();
+
+ status = ocfs2_create_new_meta_bhs(osb, handle, inode, 1, meta_ac,
+ &new_eb_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ eb = (struct ocfs2_extent_block *) new_eb_bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+
+ eb_el = &eb->h_list;
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+ fe_el = &fe->id2.i_list;
+
+ status = ocfs2_journal_access(handle, inode, new_eb_bh,
+ OCFS2_JOURNAL_ACCESS_CREATE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* copy the fe data into the new extent block */
+ eb_el->l_tree_depth = fe_el->l_tree_depth;
+ eb_el->l_next_free_rec = fe_el->l_next_free_rec;
+ for(i = 0; i < le16_to_cpu(fe_el->l_next_free_rec); i++) {
+ eb_el->l_recs[i].e_cpos = fe_el->l_recs[i].e_cpos;
+ eb_el->l_recs[i].e_clusters = fe_el->l_recs[i].e_clusters;
+ eb_el->l_recs[i].e_blkno = fe_el->l_recs[i].e_blkno;
+ }
+
+ status = ocfs2_journal_dirty(handle, new_eb_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = ocfs2_journal_access(handle, inode, fe_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* update fe now */
+ le16_add_cpu(&fe_el->l_tree_depth, 1);
+ fe_el->l_recs[0].e_cpos = 0;
+ fe_el->l_recs[0].e_blkno = eb->h_blkno;
+ fe_el->l_recs[0].e_clusters = fe->i_clusters;
+ for(i = 1; i < le16_to_cpu(fe_el->l_next_free_rec); i++) {
+ fe_el->l_recs[i].e_cpos = 0;
+ fe_el->l_recs[i].e_clusters = 0;
+ fe_el->l_recs[i].e_blkno = 0;
+ }
+ fe_el->l_next_free_rec = cpu_to_le16(1);
+
+ /* If this is our 1st tree depth shift, then last_eb_blk
+ * becomes the allocated extent block */
+ if (fe_el->l_tree_depth == cpu_to_le16(1))
+ fe->i_last_eb_blk = eb->h_blkno;
+
+ status = ocfs2_journal_dirty(handle, fe_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ *ret_new_eb_bh = new_eb_bh;
+ new_eb_bh = NULL;
+ status = 0;
+bail:
+ if (new_eb_bh)
+ brelse(new_eb_bh);
+
+ mlog_exit(status);
+ return status;
+}
+
+/*
+ * Expects the tree to already have room in the rightmost leaf for the
+ * extent. Updates all the extent blocks (and the dinode) on the way
+ * down.
+ */
+static int ocfs2_do_insert_extent(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ u64 start_blk,
+ u32 new_clusters)
+{
+ int status, i, num_bhs = 0;
+ u64 next_blkno;
+ u16 next_free;
+ struct buffer_head **eb_bhs = NULL;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+
+ mlog_entry_void();
+
+ status = ocfs2_journal_access(handle, inode, fe_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+ el = &fe->id2.i_list;
+ if (el->l_tree_depth) {
+ /* This is another operation where we want to be
+ * careful about our tree updates. An error here means
+ * none of the previous changes we made should roll
+ * forward. As a result, we have to record the buffers
+ * for this part of the tree in an array and reserve a
+ * journal write to them before making any changes. */
+ num_bhs = le16_to_cpu(fe->id2.i_list.l_tree_depth);
+ eb_bhs = kcalloc(num_bhs, sizeof(struct buffer_head *),
+ GFP_KERNEL);
+ if (!eb_bhs) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ i = 0;
+ while(el->l_tree_depth) {
+ next_free = le16_to_cpu(el->l_next_free_rec);
+ if (next_free == 0) {
+ ocfs2_error(inode->i_sb,
+ "Dinode %"MLFu64" has a bad "
+ "extent list",
+ OCFS2_I(inode)->ip_blkno);
+ status = -EIO;
+ goto bail;
+ }
+ next_blkno = le64_to_cpu(el->l_recs[next_free - 1].e_blkno);
+
+ BUG_ON(i >= num_bhs);
+ status = ocfs2_read_block(osb, next_blkno, &eb_bhs[i],
+ OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) eb_bhs[i]->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb,
+ eb);
+ status = -EIO;
+ goto bail;
+ }
+
+ status = ocfs2_journal_access(handle, inode, eb_bhs[i],
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ el = &eb->h_list;
+ i++;
+ /* When we leave this loop, eb_bhs[num_bhs - 1] will
+ * hold the bottom-most leaf extent block. */
+ }
+ BUG_ON(el->l_tree_depth);
+
+ el = &fe->id2.i_list;
+ /* If we have tree depth, then the fe update is
+ * trivial, and we want to switch el out for the
+ * bottom-most leaf in order to update it with the
+ * actual extent data below. */
+ next_free = le16_to_cpu(el->l_next_free_rec);
+ if (next_free == 0) {
+ ocfs2_error(inode->i_sb,
+ "Dinode %"MLFu64" has a bad "
+ "extent list",
+ OCFS2_I(inode)->ip_blkno);
+ status = -EIO;
+ goto bail;
+ }
+ le32_add_cpu(&el->l_recs[next_free - 1].e_clusters,
+ new_clusters);
+ /* (num_bhs - 1) to avoid the leaf */
+ for(i = 0; i < (num_bhs - 1); i++) {
+ eb = (struct ocfs2_extent_block *) eb_bhs[i]->b_data;
+ el = &eb->h_list;
+
+ /* finally, make our actual change to the
+ * intermediate extent blocks. */
+ next_free = le16_to_cpu(el->l_next_free_rec);
+ le32_add_cpu(&el->l_recs[next_free - 1].e_clusters,
+ new_clusters);
+
+ status = ocfs2_journal_dirty(handle, eb_bhs[i]);
+ if (status < 0)
+ mlog_errno(status);
+ }
+ BUG_ON(i != (num_bhs - 1));
+ /* note that the leaf block wasn't touched in
+ * the loop above */
+ eb = (struct ocfs2_extent_block *) eb_bhs[num_bhs - 1]->b_data;
+ el = &eb->h_list;
+ BUG_ON(el->l_tree_depth);
+ }
+
+ /* yay, we can finally add the actual extent now! */
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+ if (le16_to_cpu(el->l_next_free_rec) &&
+ ocfs2_extent_contig(inode, &el->l_recs[i], start_blk)) {
+ le32_add_cpu(&el->l_recs[i].e_clusters, new_clusters);
+ } else if (le16_to_cpu(el->l_next_free_rec) &&
+ (le32_to_cpu(el->l_recs[i].e_clusters) == 0)) {
+ /* having an empty extent at eof is legal. */
+ if (el->l_recs[i].e_cpos != fe->i_clusters) {
+ ocfs2_error(inode->i_sb,
+ "Dinode %"MLFu64" trailing extent is bad: "
+ "cpos (%u) != number of clusters (%u)",
+ le32_to_cpu(el->l_recs[i].e_cpos),
+ le32_to_cpu(fe->i_clusters));
+ status = -EIO;
+ goto bail;
+ }
+ el->l_recs[i].e_blkno = cpu_to_le64(start_blk);
+ el->l_recs[i].e_clusters = cpu_to_le32(new_clusters);
+ } else {
+ /* No contiguous record, or no empty record at eof, so
+ * we add a new one. */
+
+ BUG_ON(le16_to_cpu(el->l_next_free_rec) >=
+ le16_to_cpu(el->l_count));
+ i = le16_to_cpu(el->l_next_free_rec);
+
+ el->l_recs[i].e_blkno = cpu_to_le64(start_blk);
+ el->l_recs[i].e_clusters = cpu_to_le32(new_clusters);
+ el->l_recs[i].e_cpos = fe->i_clusters;
+ le16_add_cpu(&el->l_next_free_rec, 1);
+ }
+
+ /*
+ * extent_map errors are not fatal, so they are ignored outside
+ * of flushing the thing.
+ */
+ status = ocfs2_extent_map_append(inode, &el->l_recs[i],
+ new_clusters);
+ if (status) {
+ mlog_errno(status);
+ ocfs2_extent_map_drop(inode, le32_to_cpu(fe->i_clusters));
+ }
+
+ status = ocfs2_journal_dirty(handle, fe_bh);
+ if (status < 0)
+ mlog_errno(status);
+ if (fe->id2.i_list.l_tree_depth) {
+ status = ocfs2_journal_dirty(handle, eb_bhs[num_bhs - 1]);
+ if (status < 0)
+ mlog_errno(status);
+ }
+
+ status = 0;
+bail:
+ if (eb_bhs) {
+ for (i = 0; i < num_bhs; i++)
+ if (eb_bhs[i])
+ brelse(eb_bhs[i]);
+ kfree(eb_bhs);
+ }
+
+ mlog_exit(status);
+ return status;
+}
+
+/*
+ * Should only be called when there is no space left in any of the
+ * leaf nodes. What we want to do is find the lowest tree depth
+ * non-leaf extent block with room for new records. There are three
+ * valid results of this search:
+ *
+ * 1) a lowest extent block is found, then we pass it back in
+ * *lowest_eb_bh and return '0'
+ *
+ * 2) the search fails to find anything, but the dinode has room. We
+ * pass NULL back in *lowest_eb_bh, but still return '0'
+ *
+ * 3) the search fails to find anything AND the dinode is full, in
+ * which case we return > 0
+ *
+ * return status < 0 indicates an error.
+ */
+static int ocfs2_find_branch_target(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct buffer_head **target_bh)
+{
+ int status = 0, i;
+ u64 blkno;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+ struct buffer_head *bh = NULL;
+ struct buffer_head *lowest_bh = NULL;
+
+ mlog_entry_void();
+
+ *target_bh = NULL;
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+ el = &fe->id2.i_list;
+
+ while(le16_to_cpu(el->l_tree_depth) > 1) {
+ if (le16_to_cpu(el->l_next_free_rec) == 0) {
+ ocfs2_error(inode->i_sb, "Dinode %"MLFu64" has empty "
+ "extent list (next_free_rec == 0)",
+ OCFS2_I(inode)->ip_blkno);
+ status = -EIO;
+ goto bail;
+ }
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+ blkno = le64_to_cpu(el->l_recs[i].e_blkno);
+ if (!blkno) {
+ ocfs2_error(inode->i_sb, "Dinode %"MLFu64" has extent "
+ "list where extent # %d has no physical "
+ "block start",
+ OCFS2_I(inode)->ip_blkno, i);
+ status = -EIO;
+ goto bail;
+ }
+
+ if (bh) {
+ brelse(bh);
+ bh = NULL;
+ }
+
+ status = ocfs2_read_block(osb, blkno, &bh, OCFS2_BH_CACHED,
+ inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ eb = (struct ocfs2_extent_block *) bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+ el = &eb->h_list;
+
+ if (le16_to_cpu(el->l_next_free_rec) <
+ le16_to_cpu(el->l_count)) {
+ if (lowest_bh)
+ brelse(lowest_bh);
+ lowest_bh = bh;
+ get_bh(lowest_bh);
+ }
+ }
+
+ /* If we didn't find one and the fe doesn't have any room,
+ * then return '1' */
+ if (!lowest_bh
+ && (fe->id2.i_list.l_next_free_rec == fe->id2.i_list.l_count))
+ status = 1;
+
+ *target_bh = lowest_bh;
+bail:
+ if (bh)
+ brelse(bh);
+
+ mlog_exit(status);
+ return status;
+}
+
+/* the caller needs to update fe->i_clusters */
+int ocfs2_insert_extent(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ u64 start_blk,
+ u32 new_clusters,
+ struct ocfs2_alloc_context *meta_ac)
+{
+ int status, i, shift;
+ struct buffer_head *last_eb_bh = NULL;
+ struct buffer_head *bh = NULL;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+
+ mlog_entry_void();
+
+ mlog(0, "add %u clusters starting at block %"MLFu64" to "
+ "inode %"MLFu64"\n",
+ new_clusters, start_blk, OCFS2_I(inode)->ip_blkno);
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+ el = &fe->id2.i_list;
+
+ if (el->l_tree_depth) {
+ /* jump to end of tree */
+ status = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
+ &last_eb_bh, OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_exit(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+ el = &eb->h_list;
+ }
+
+ /* Can we allocate without adding/shifting tree bits? */
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+ if (le16_to_cpu(el->l_next_free_rec) == 0
+ || (le16_to_cpu(el->l_next_free_rec) < le16_to_cpu(el->l_count))
+ || le32_to_cpu(el->l_recs[i].e_clusters) == 0
+ || ocfs2_extent_contig(inode, &el->l_recs[i], start_blk))
+ goto out_add;
+
+ mlog(0, "ocfs2_allocate_extent: couldn't do a simple add, traversing "
+ "tree now.\n");
+
+ shift = ocfs2_find_branch_target(osb, inode, fe_bh, &bh);
+ if (shift < 0) {
+ status = shift;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* We traveled all the way to the bottom of the allocation tree
+ * and didn't find room for any more extents - we need to add
+ * another tree level */
+ if (shift) {
+ /* if we hit a leaf, we'd better be empty :) */
+ BUG_ON(le16_to_cpu(el->l_next_free_rec) !=
+ le16_to_cpu(el->l_count));
+ BUG_ON(bh);
+ mlog(0, "ocfs2_allocate_extent: need to shift tree depth "
+ "(current = %u)\n",
+ le16_to_cpu(fe->id2.i_list.l_tree_depth));
+
+ /* ocfs2_shift_tree_depth will return us a buffer with
+ * the new extent block (so we can pass that to
+ * ocfs2_add_branch). */
+ status = ocfs2_shift_tree_depth(osb, handle, inode, fe_bh,
+ meta_ac, &bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ /* Special case: we have room now if we shifted from
+ * tree_depth 0 */
+ if (fe->id2.i_list.l_tree_depth == cpu_to_le16(1))
+ goto out_add;
+ }
+
+ /* call ocfs2_add_branch to add the final part of the tree with
+ * the new data. */
+ mlog(0, "ocfs2_allocate_extent: add branch. bh = %p\n", bh);
+ status = ocfs2_add_branch(osb, handle, inode, fe_bh, bh, last_eb_bh,
+ meta_ac);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+out_add:
+ /* Finally, we can add clusters. */
+ status = ocfs2_do_insert_extent(osb, handle, inode, fe_bh,
+ start_blk, new_clusters);
+ if (status < 0)
+ mlog_errno(status);
+
+bail:
+ if (bh)
+ brelse(bh);
+
+ if (last_eb_bh)
+ brelse(last_eb_bh);
+
+ mlog_exit(status);
+ return status;
+}
+
+static inline int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
+{
+ struct buffer_head *tl_bh = osb->osb_tl_bh;
+ struct ocfs2_dinode *di;
+ struct ocfs2_truncate_log *tl;
+
+ di = (struct ocfs2_dinode *) tl_bh->b_data;
+ tl = &di->id2.i_dealloc;
+
+ mlog_bug_on_msg(le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count),
+ "slot %d, invalid truncate log parameters: used = "
+ "%u, count = %u\n", osb->slot_num,
+ le16_to_cpu(tl->tl_used), le16_to_cpu(tl->tl_count));
+ return le16_to_cpu(tl->tl_used) == le16_to_cpu(tl->tl_count);
+}
+
+static int ocfs2_truncate_log_can_coalesce(struct ocfs2_truncate_log *tl,
+ unsigned int new_start)
+{
+ unsigned int tail_index;
+ unsigned int current_tail;
+
+ /* No records, nothing to coalesce */
+ if (!le16_to_cpu(tl->tl_used))
+ return 0;
+
+ tail_index = le16_to_cpu(tl->tl_used) - 1;
+ current_tail = le32_to_cpu(tl->tl_recs[tail_index].t_start);
+ current_tail += le32_to_cpu(tl->tl_recs[tail_index].t_clusters);
+
+ return current_tail == new_start;
+}
+
+static int ocfs2_truncate_log_append(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ u64 start_blk,
+ unsigned int num_clusters)
+{
+ int status, index;
+ unsigned int start_cluster, tl_count;
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct buffer_head *tl_bh = osb->osb_tl_bh;
+ struct ocfs2_dinode *di;
+ struct ocfs2_truncate_log *tl;
+
+ mlog_entry("start_blk = %"MLFu64", num_clusters = %u\n", start_blk,
+ num_clusters);
+
+ BUG_ON(!down_trylock(&tl_inode->i_sem));
+
+ start_cluster = ocfs2_blocks_to_clusters(osb->sb, start_blk);
+
+ di = (struct ocfs2_dinode *) tl_bh->b_data;
+ tl = &di->id2.i_dealloc;
+ if (!OCFS2_IS_VALID_DINODE(di)) {
+ OCFS2_RO_ON_INVALID_DINODE(osb->sb, di);
+ status = -EIO;
+ goto bail;
+ }
+
+ tl_count = le16_to_cpu(tl->tl_count);
+ mlog_bug_on_msg(tl_count > ocfs2_truncate_recs_per_inode(osb->sb) ||
+ tl_count == 0,
+ "Truncate record count on #%"MLFu64" invalid ("
+ "wanted %u, actual %u\n", OCFS2_I(tl_inode)->ip_blkno,
+ ocfs2_truncate_recs_per_inode(osb->sb),
+ le16_to_cpu(tl->tl_count));
+
+ /* Caller should have known to flush before calling us. */
+ index = le16_to_cpu(tl->tl_used);
+ if (index >= tl_count) {
+ status = -ENOSPC;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = ocfs2_journal_access(handle, tl_inode, tl_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ mlog(0, "Log truncate of %u clusters starting at cluster %u to "
+ "%"MLFu64" (index = %d)\n", num_clusters, start_cluster,
+ OCFS2_I(tl_inode)->ip_blkno, index);
+
+ if (ocfs2_truncate_log_can_coalesce(tl, start_cluster)) {
+ /*
+ * Move index back to the record we are coalescing with.
+ * ocfs2_truncate_log_can_coalesce() guarantees nonzero
+ */
+ index--;
+
+ num_clusters += le32_to_cpu(tl->tl_recs[index].t_clusters);
+ mlog(0, "Coalesce with index %u (start = %u, clusters = %u)\n",
+ index, le32_to_cpu(tl->tl_recs[index].t_start),
+ num_clusters);
+ } else {
+ tl->tl_recs[index].t_start = cpu_to_le32(start_cluster);
+ tl->tl_used = cpu_to_le16(index + 1);
+ }
+ tl->tl_recs[index].t_clusters = cpu_to_le32(num_clusters);
+
+ status = ocfs2_journal_dirty(handle, tl_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+bail:
+ mlog_exit(status);
+ return status;
+}
+
+static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *data_alloc_inode,
+ struct buffer_head *data_alloc_bh)
+{
+ int status = 0;
+ int i;
+ unsigned int num_clusters;
+ u64 start_blk;
+ struct ocfs2_truncate_rec rec;
+ struct ocfs2_dinode *di;
+ struct ocfs2_truncate_log *tl;
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct buffer_head *tl_bh = osb->osb_tl_bh;
+
+ mlog_entry_void();
+
+ di = (struct ocfs2_dinode *) tl_bh->b_data;
+ tl = &di->id2.i_dealloc;
+ i = le16_to_cpu(tl->tl_used) - 1;
+ while (i >= 0) {
+ /* Caller has given us at least enough credits to
+ * update the truncate log dinode */
+ status = ocfs2_journal_access(handle, tl_inode, tl_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ tl->tl_used = cpu_to_le16(i);
+
+ status = ocfs2_journal_dirty(handle, tl_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* TODO: Perhaps we can calculate the bulk of the
+ * credits up front rather than extending like
+ * this. */
+ status = ocfs2_extend_trans(handle,
+ OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ rec = tl->tl_recs[i];
+ start_blk = ocfs2_clusters_to_blocks(data_alloc_inode->i_sb,
+ le32_to_cpu(rec.t_start));
+ num_clusters = le32_to_cpu(rec.t_clusters);
+
+ /* if start_blk is not set, we ignore the record as
+ * invalid. */
+ if (start_blk) {
+ mlog(0, "free record %d, start = %u, clusters = %u\n",
+ i, le32_to_cpu(rec.t_start), num_clusters);
+
+ status = ocfs2_free_clusters(handle, data_alloc_inode,
+ data_alloc_bh, start_blk,
+ num_clusters);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+ i--;
+ }
+
+bail:
+ mlog_exit(status);
+ return status;
+}
+
+/* Expects you to already be holding tl_inode->i_sem */
+static int __ocfs2_flush_truncate_log(struct ocfs2_super *osb)
+{
+ int status;
+ unsigned int num_to_flush;
+ struct ocfs2_journal_handle *handle = NULL;
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct inode *data_alloc_inode = NULL;
+ struct buffer_head *tl_bh = osb->osb_tl_bh;
+ struct buffer_head *data_alloc_bh = NULL;
+ struct ocfs2_dinode *di;
+ struct ocfs2_truncate_log *tl;
+
+ mlog_entry_void();
+
+ BUG_ON(!down_trylock(&tl_inode->i_sem));
+
+ di = (struct ocfs2_dinode *) tl_bh->b_data;
+ tl = &di->id2.i_dealloc;
+ if (!OCFS2_IS_VALID_DINODE(di)) {
+ OCFS2_RO_ON_INVALID_DINODE(osb->sb, di);
+ status = -EIO;
+ goto bail;
+ }
+
+ num_to_flush = le16_to_cpu(tl->tl_used);
+ mlog(0, "Flush %u records from truncate log #%"MLFu64"\n",
+ num_to_flush, OCFS2_I(tl_inode)->ip_blkno);
+ if (!num_to_flush) {
+ status = 0;
+ goto bail;
+ }
+
+ handle = ocfs2_alloc_handle(osb);
+ if (!handle) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ data_alloc_inode = ocfs2_get_system_file_inode(osb,
+ GLOBAL_BITMAP_SYSTEM_INODE,
+ OCFS2_INVALID_SLOT);
+ if (!data_alloc_inode) {
+ status = -EINVAL;
+ mlog(ML_ERROR, "Could not get bitmap inode!\n");
+ goto bail;
+ }
+
+ ocfs2_handle_add_inode(handle, data_alloc_inode);
+ status = ocfs2_meta_lock(data_alloc_inode, handle, &data_alloc_bh, 1);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ handle = ocfs2_start_trans(osb, handle, OCFS2_TRUNCATE_LOG_UPDATE);
+ if (IS_ERR(handle)) {
+ status = PTR_ERR(handle);
+ handle = NULL;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = ocfs2_replay_truncate_records(osb, handle, data_alloc_inode,
+ data_alloc_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+bail:
+ if (handle)
+ ocfs2_commit_trans(handle);
+
+ if (data_alloc_inode)
+ iput(data_alloc_inode);
+
+ if (data_alloc_bh)
+ brelse(data_alloc_bh);
+
+ mlog_exit(status);
+ return status;
+}
+
+int ocfs2_flush_truncate_log(struct ocfs2_super *osb)
+{
+ int status;
+ struct inode *tl_inode = osb->osb_tl_inode;
+
+ down(&tl_inode->i_sem);
+ status = __ocfs2_flush_truncate_log(osb);
+ up(&tl_inode->i_sem);
+
+ return status;
+}
+
+static void ocfs2_truncate_log_worker(void *data)
+{
+ int status;
+ struct ocfs2_super *osb = data;
+
+ mlog_entry_void();
+
+ status = ocfs2_flush_truncate_log(osb);
+ if (status < 0)
+ mlog_errno(status);
+
+ mlog_exit(status);
+}
+
+#define OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL (2 * HZ)
+void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
+ int cancel)
+{
+ if (osb->osb_tl_inode) {
+ /* We want to push off log flushes while truncates are
+ * still running. */
+ if (cancel)
+ cancel_delayed_work(&osb->osb_truncate_log_wq);
+
+ queue_delayed_work(ocfs2_wq, &osb->osb_truncate_log_wq,
+ OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL);
+ }
+}
+
+static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
+ int slot_num,
+ struct inode **tl_inode,
+ struct buffer_head **tl_bh)
+{
+ int status;
+ struct inode *inode = NULL;
+ struct buffer_head *bh = NULL;
+
+ inode = ocfs2_get_system_file_inode(osb,
+ TRUNCATE_LOG_SYSTEM_INODE,
+ slot_num);
+ if (!inode) {
+ status = -EINVAL;
+ mlog(ML_ERROR, "Could not get load truncate log inode!\n");
+ goto bail;
+ }
+
+ status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &bh,
+ OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ iput(inode);
+ mlog_errno(status);
+ goto bail;
+ }
+
+ *tl_inode = inode;
+ *tl_bh = bh;
+bail:
+ mlog_exit(status);
+ return status;
+}
+
+/* called during the 1st stage of node recovery. we stamp a clean
+ * truncate log and pass back a copy for processing later. if the
+ * truncate log does not require processing, a *tl_copy is set to
+ * NULL. */
+int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
+ int slot_num,
+ struct ocfs2_dinode **tl_copy)
+{
+ int status;
+ struct inode *tl_inode = NULL;
+ struct buffer_head *tl_bh = NULL;
+ struct ocfs2_dinode *di;
+ struct ocfs2_truncate_log *tl;
+
+ *tl_copy = NULL;
+
+ mlog(0, "recover truncate log from slot %d\n", slot_num);
+
+ status = ocfs2_get_truncate_log_info(osb, slot_num, &tl_inode, &tl_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ di = (struct ocfs2_dinode *) tl_bh->b_data;
+ tl = &di->id2.i_dealloc;
+ if (!OCFS2_IS_VALID_DINODE(di)) {
+ OCFS2_RO_ON_INVALID_DINODE(tl_inode->i_sb, di);
+ status = -EIO;
+ goto bail;
+ }
+
+ if (le16_to_cpu(tl->tl_used)) {
+ mlog(0, "We'll have %u logs to recover\n",
+ le16_to_cpu(tl->tl_used));
+
+ *tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL);
+ if (!(*tl_copy)) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* Assuming the write-out below goes well, this copy
+ * will be passed back to recovery for processing. */
+ memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size);
+
+ /* All we need to do to clear the truncate log is set
+ * tl_used. */
+ tl->tl_used = 0;
+
+ status = ocfs2_write_block(osb, tl_bh, tl_inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+bail:
+ if (tl_inode)
+ iput(tl_inode);
+ if (tl_bh)
+ brelse(tl_bh);
+
+ if (status < 0 && (*tl_copy)) {
+ kfree(*tl_copy);
+ *tl_copy = NULL;
+ }
+
+ mlog_exit(status);
+ return status;
+}
+
+int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
+ struct ocfs2_dinode *tl_copy)
+{
+ int status = 0;
+ int i;
+ unsigned int clusters, num_recs, start_cluster;
+ u64 start_blk;
+ struct ocfs2_journal_handle *handle;
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct ocfs2_truncate_log *tl;
+
+ mlog_entry_void();
+
+ if (OCFS2_I(tl_inode)->ip_blkno == le64_to_cpu(tl_copy->i_blkno)) {
+ mlog(ML_ERROR, "Asked to recover my own truncate log!\n");
+ return -EINVAL;
+ }
+
+ tl = &tl_copy->id2.i_dealloc;
+ num_recs = le16_to_cpu(tl->tl_used);
+ mlog(0, "cleanup %u records from %"MLFu64"\n", num_recs,
+ tl_copy->i_blkno);
+
+ down(&tl_inode->i_sem);
+ for(i = 0; i < num_recs; i++) {
+ if (ocfs2_truncate_log_needs_flush(osb)) {
+ status = __ocfs2_flush_truncate_log(osb);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail_up;
+ }
+ }
+
+ handle = ocfs2_start_trans(osb, NULL,
+ OCFS2_TRUNCATE_LOG_UPDATE);
+ if (IS_ERR(handle)) {
+ status = PTR_ERR(handle);
+ mlog_errno(status);
+ goto bail_up;
+ }
+
+ clusters = le32_to_cpu(tl->tl_recs[i].t_clusters);
+ start_cluster = le32_to_cpu(tl->tl_recs[i].t_start);
+ start_blk = ocfs2_clusters_to_blocks(osb->sb, start_cluster);
+
+ status = ocfs2_truncate_log_append(osb, handle,
+ start_blk, clusters);
+ ocfs2_commit_trans(handle);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail_up;
+ }
+ }
+
+bail_up:
+ up(&tl_inode->i_sem);
+
+ mlog_exit(status);
+ return status;
+}
+
+void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb)
+{
+ int status;
+ struct inode *tl_inode = osb->osb_tl_inode;
+
+ mlog_entry_void();
+
+ if (tl_inode) {
+ cancel_delayed_work(&osb->osb_truncate_log_wq);
+ flush_workqueue(ocfs2_wq);
+
+ status = ocfs2_flush_truncate_log(osb);
+ if (status < 0)
+ mlog_errno(status);
+
+ brelse(osb->osb_tl_bh);
+ iput(osb->osb_tl_inode);
+ }
+
+ mlog_exit_void();
+}
+
+int ocfs2_truncate_log_init(struct ocfs2_super *osb)
+{
+ int status;
+ struct inode *tl_inode = NULL;
+ struct buffer_head *tl_bh = NULL;
+
+ mlog_entry_void();
+
+ status = ocfs2_get_truncate_log_info(osb,
+ osb->slot_num,
+ &tl_inode,
+ &tl_bh);
+ if (status < 0)
+ mlog_errno(status);
+
+ /* ocfs2_truncate_log_shutdown keys on the existence of
+ * osb->osb_tl_inode so we don't set any of the osb variables
+ * until we're sure all is well. */
+ INIT_WORK(&osb->osb_truncate_log_wq, ocfs2_truncate_log_worker, osb);
+ osb->osb_tl_bh = tl_bh;
+ osb->osb_tl_inode = tl_inode;
+
+ mlog_exit(status);
+ return status;
+}
+
+/* This function will figure out whether the currently last extent
+ * block will be deleted, and if it will, what the new last extent
+ * block will be so we can update his h_next_leaf_blk field, as well
+ * as the dinodes i_last_eb_blk */
+static int ocfs2_find_new_last_ext_blk(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct ocfs2_dinode *fe,
+ u32 new_i_clusters,
+ struct buffer_head *old_last_eb,
+ struct buffer_head **new_last_eb)
+{
+ int i, status = 0;
+ u64 block = 0;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+ struct buffer_head *bh = NULL;
+
+ *new_last_eb = NULL;
+
+ if (!OCFS2_IS_VALID_DINODE(fe)) {
+ OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
+ status = -EIO;
+ goto bail;
+ }
+
+ /* we have no tree, so of course, no last_eb. */
+ if (!fe->id2.i_list.l_tree_depth)
+ goto bail;
+
+ /* trunc to zero special case - this makes tree_depth = 0
+ * regardless of what it is. */
+ if (!new_i_clusters)
+ goto bail;
+
+ eb = (struct ocfs2_extent_block *) old_last_eb->b_data;
+ el = &(eb->h_list);
+ BUG_ON(!el->l_next_free_rec);
+
+ /* Make sure that this guy will actually be empty after we
+ * clear away the data. */
+ if (le32_to_cpu(el->l_recs[0].e_cpos) < new_i_clusters)
+ goto bail;
+
+ /* Ok, at this point, we know that last_eb will definitely
+ * change, so lets traverse the tree and find the second to
+ * last extent block. */
+ el = &(fe->id2.i_list);
+ /* go down the tree, */
+ do {
+ for(i = (le16_to_cpu(el->l_next_free_rec) - 1); i >= 0; i--) {
+ if (le32_to_cpu(el->l_recs[i].e_cpos) <
+ new_i_clusters) {
+ block = le64_to_cpu(el->l_recs[i].e_blkno);
+ break;
+ }
+ }
+ BUG_ON(i < 0);
+
+ if (bh) {
+ brelse(bh);
+ bh = NULL;
+ }
+
+ status = ocfs2_read_block(osb, block, &bh, OCFS2_BH_CACHED,
+ inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) bh->b_data;
+ el = &eb->h_list;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+ } while (el->l_tree_depth);
+
+ *new_last_eb = bh;
+ get_bh(*new_last_eb);
+ mlog(0, "returning block %"MLFu64"\n", le64_to_cpu(eb->h_blkno));
+bail:
+ if (bh)
+ brelse(bh);
+
+ return status;
+}
+
+static int ocfs2_do_truncate(struct ocfs2_super *osb,
+ unsigned int clusters_to_del,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct buffer_head *old_last_eb_bh,
+ struct ocfs2_journal_handle *handle,
+ struct ocfs2_truncate_context *tc)
+{
+ int status, i, depth;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_block *last_eb = NULL;
+ struct ocfs2_extent_list *el;
+ struct buffer_head *eb_bh = NULL;
+ struct buffer_head *last_eb_bh = NULL;
+ u64 next_eb = 0;
+ u64 delete_blk = 0;
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+
+ status = ocfs2_find_new_last_ext_blk(osb,
+ inode,
+ fe,
+ le32_to_cpu(fe->i_clusters) -
+ clusters_to_del,
+ old_last_eb_bh,
+ &last_eb_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ if (last_eb_bh)
+ last_eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+
+ status = ocfs2_journal_access(handle, inode, fe_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ el = &(fe->id2.i_list);
+
+ spin_lock(&OCFS2_I(inode)->ip_lock);
+ OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters) -
+ clusters_to_del;
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+ le32_add_cpu(&fe->i_clusters, -clusters_to_del);
+ fe->i_mtime = cpu_to_le64(CURRENT_TIME.tv_sec);
+ fe->i_mtime_nsec = cpu_to_le32(CURRENT_TIME.tv_nsec);
+
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+
+ BUG_ON(le32_to_cpu(el->l_recs[i].e_clusters) < clusters_to_del);
+ le32_add_cpu(&el->l_recs[i].e_clusters, -clusters_to_del);
+ /* tree depth zero, we can just delete the clusters, otherwise
+ * we need to record the offset of the next level extent block
+ * as we may overwrite it. */
+ if (!el->l_tree_depth)
+ delete_blk = le64_to_cpu(el->l_recs[i].e_blkno)
+ + ocfs2_clusters_to_blocks(osb->sb,
+ le32_to_cpu(el->l_recs[i].e_clusters));
+ else
+ next_eb = le64_to_cpu(el->l_recs[i].e_blkno);
+
+ if (!el->l_recs[i].e_clusters) {
+ /* if we deleted the whole extent record, then clear
+ * out the other fields and update the extent
+ * list. For depth > 0 trees, we've already recorded
+ * the extent block in 'next_eb' */
+ el->l_recs[i].e_cpos = 0;
+ el->l_recs[i].e_blkno = 0;
+ BUG_ON(!el->l_next_free_rec);
+ le16_add_cpu(&el->l_next_free_rec, -1);
+ }
+
+ depth = le16_to_cpu(el->l_tree_depth);
+ if (!fe->i_clusters) {
+ /* trunc to zero is a special case. */
+ el->l_tree_depth = 0;
+ fe->i_last_eb_blk = 0;
+ } else if (last_eb)
+ fe->i_last_eb_blk = last_eb->h_blkno;
+
+ status = ocfs2_journal_dirty(handle, fe_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ if (last_eb) {
+ /* If there will be a new last extent block, then by
+ * definition, there cannot be any leaves to the right of
+ * him. */
+ status = ocfs2_journal_access(handle, inode, last_eb_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ last_eb->h_next_leaf_blk = 0;
+ status = ocfs2_journal_dirty(handle, last_eb_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+ /* if our tree depth > 0, update all the tree blocks below us. */
+ while (depth) {
+ mlog(0, "traveling tree (depth = %d, next_eb = %"MLFu64")\n",
+ depth, next_eb);
+ status = ocfs2_read_block(osb, next_eb, &eb_bh,
+ OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *)eb_bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+ el = &(eb->h_list);
+
+ status = ocfs2_journal_access(handle, inode, eb_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
+ BUG_ON(depth != (le16_to_cpu(el->l_tree_depth) + 1));
+
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+
+ mlog(0, "extent block %"MLFu64", before: record %d: "
+ "(%u, %u, %"MLFu64"), next = %u\n",
+ le64_to_cpu(eb->h_blkno), i,
+ le32_to_cpu(el->l_recs[i].e_cpos),
+ le32_to_cpu(el->l_recs[i].e_clusters),
+ le64_to_cpu(el->l_recs[i].e_blkno),
+ le16_to_cpu(el->l_next_free_rec));
+
+ BUG_ON(le32_to_cpu(el->l_recs[i].e_clusters) < clusters_to_del);
+ le32_add_cpu(&el->l_recs[i].e_clusters, -clusters_to_del);
+
+ next_eb = le64_to_cpu(el->l_recs[i].e_blkno);
+ /* bottom-most block requires us to delete data.*/
+ if (!el->l_tree_depth)
+ delete_blk = le64_to_cpu(el->l_recs[i].e_blkno)
+ + ocfs2_clusters_to_blocks(osb->sb,
+ le32_to_cpu(el->l_recs[i].e_clusters));
+ if (!el->l_recs[i].e_clusters) {
+ el->l_recs[i].e_cpos = 0;
+ el->l_recs[i].e_blkno = 0;
+ BUG_ON(!el->l_next_free_rec);
+ le16_add_cpu(&el->l_next_free_rec, -1);
+ }
+ mlog(0, "extent block %"MLFu64", after: record %d: "
+ "(%u, %u, %"MLFu64"), next = %u\n",
+ le64_to_cpu(eb->h_blkno), i,
+ le32_to_cpu(el->l_recs[i].e_cpos),
+ le32_to_cpu(el->l_recs[i].e_clusters),
+ le64_to_cpu(el->l_recs[i].e_blkno),
+ le16_to_cpu(el->l_next_free_rec));
+
+ status = ocfs2_journal_dirty(handle, eb_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ if (!el->l_next_free_rec) {
+ mlog(0, "deleting this extent block.\n");
+
+ ocfs2_remove_from_cache(inode, eb_bh);
+
+ BUG_ON(eb->h_suballoc_slot);
+ BUG_ON(el->l_recs[0].e_clusters);
+ BUG_ON(el->l_recs[0].e_cpos);
+ BUG_ON(el->l_recs[0].e_blkno);
+ status = ocfs2_free_extent_block(handle,
+ tc->tc_ext_alloc_inode,
+ tc->tc_ext_alloc_bh,
+ eb);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+ brelse(eb_bh);
+ eb_bh = NULL;
+ depth--;
+ }
+
+ BUG_ON(!delete_blk);
+ status = ocfs2_truncate_log_append(osb, handle, delete_blk,
+ clusters_to_del);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ status = 0;
+bail:
+ if (!status)
+ ocfs2_extent_map_trunc(inode, le32_to_cpu(fe->i_clusters));
+ else
+ ocfs2_extent_map_drop(inode, 0);
+ mlog_exit(status);
+ return status;
+}
+
+/*
+ * It is expected, that by the time you call this function,
+ * inode->i_size and fe->i_size have been adjusted.
+ *
+ * WARNING: This will kfree the truncate context
+ */
+int ocfs2_commit_truncate(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_truncate_context *tc)
+{
+ int status, i, credits, tl_sem = 0;
+ u32 clusters_to_del, target_i_clusters;
+ u64 last_eb = 0;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+ struct buffer_head *last_eb_bh;
+ struct ocfs2_journal_handle *handle = NULL;
+ struct inode *tl_inode = osb->osb_tl_inode;
+
+ mlog_entry_void();
+
+ down_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ target_i_clusters = ocfs2_clusters_for_bytes(osb->sb,
+ i_size_read(inode));
+
+ last_eb_bh = tc->tc_last_eb_bh;
+ tc->tc_last_eb_bh = NULL;
+
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+
+ if (fe->id2.i_list.l_tree_depth) {
+ eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+ el = &eb->h_list;
+ } else
+ el = &fe->id2.i_list;
+ last_eb = le64_to_cpu(fe->i_last_eb_blk);
+start:
+ mlog(0, "ocfs2_commit_truncate: fe->i_clusters = %u, "
+ "last_eb = %"MLFu64", fe->i_last_eb_blk = %"MLFu64", "
+ "fe->id2.i_list.l_tree_depth = %u last_eb_bh = %p\n",
+ le32_to_cpu(fe->i_clusters), last_eb,
+ le64_to_cpu(fe->i_last_eb_blk),
+ le16_to_cpu(fe->id2.i_list.l_tree_depth), last_eb_bh);
+
+ if (last_eb != le64_to_cpu(fe->i_last_eb_blk)) {
+ mlog(0, "last_eb changed!\n");
+ BUG_ON(!fe->id2.i_list.l_tree_depth);
+ last_eb = le64_to_cpu(fe->i_last_eb_blk);
+ /* i_last_eb_blk may have changed, read it if
+ * necessary. We don't have to worry about the
+ * truncate to zero case here (where there becomes no
+ * last_eb) because we never loop back after our work
+ * is done. */
+ if (last_eb_bh) {
+ brelse(last_eb_bh);
+ last_eb_bh = NULL;
+ }
+
+ status = ocfs2_read_block(osb, last_eb,
+ &last_eb_bh, OCFS2_BH_CACHED,
+ inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+ status = -EIO;
+ goto bail;
+ }
+ el = &(eb->h_list);
+ }
+
+ /* by now, el will point to the extent list on the bottom most
+ * portion of this tree. */
+ i = le16_to_cpu(el->l_next_free_rec) - 1;
+ if (le32_to_cpu(el->l_recs[i].e_cpos) >= target_i_clusters)
+ clusters_to_del = le32_to_cpu(el->l_recs[i].e_clusters);
+ else
+ clusters_to_del = (le32_to_cpu(el->l_recs[i].e_clusters) +
+ le32_to_cpu(el->l_recs[i].e_cpos)) -
+ target_i_clusters;
+
+ mlog(0, "clusters_to_del = %u in this pass\n", clusters_to_del);
+
+ down(&tl_inode->i_sem);
+ tl_sem = 1;
+ /* ocfs2_truncate_log_needs_flush guarantees us at least one
+ * record is free for use. If there isn't any, we flush to get
+ * an empty truncate log. */
+ if (ocfs2_truncate_log_needs_flush(osb)) {
+ status = __ocfs2_flush_truncate_log(osb);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+ credits = ocfs2_calc_tree_trunc_credits(osb->sb, clusters_to_del,
+ fe, el);
+ handle = ocfs2_start_trans(osb, NULL, credits);
+ if (IS_ERR(handle)) {
+ status = PTR_ERR(handle);
+ handle = NULL;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+ status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
+ if (status < 0)
+ mlog_errno(status);
+
+ status = ocfs2_do_truncate(osb, clusters_to_del, inode, fe_bh,
+ last_eb_bh, handle, tc);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ up(&tl_inode->i_sem);
+ tl_sem = 0;
+
+ ocfs2_commit_trans(handle);
+ handle = NULL;
+
+ BUG_ON(le32_to_cpu(fe->i_clusters) < target_i_clusters);
+ if (le32_to_cpu(fe->i_clusters) > target_i_clusters)
+ goto start;
+bail:
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ocfs2_schedule_truncate_log_flush(osb, 1);
+
+ if (tl_sem)
+ up(&tl_inode->i_sem);
+
+ if (handle)
+ ocfs2_commit_trans(handle);
+
+ if (last_eb_bh)
+ brelse(last_eb_bh);
+
+ /* This will drop the ext_alloc cluster lock for us */
+ ocfs2_free_truncate_context(tc);
+
+ mlog_exit(status);
+ return status;
+}
+
+
+/*
+ * Expects the inode to already be locked. This will figure out which
+ * inodes need to be locked and will put them on the returned truncate
+ * context.
+ */
+int ocfs2_prepare_truncate(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_truncate_context **tc)
+{
+ int status, metadata_delete;
+ unsigned int new_i_clusters;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_extent_block *eb;
+ struct ocfs2_extent_list *el;
+ struct buffer_head *last_eb_bh = NULL;
+ struct inode *ext_alloc_inode = NULL;
+ struct buffer_head *ext_alloc_bh = NULL;
+
+ mlog_entry_void();
+
+ *tc = NULL;
+
+ new_i_clusters = ocfs2_clusters_for_bytes(osb->sb,
+ i_size_read(inode));
+ fe = (struct ocfs2_dinode *) fe_bh->b_data;
+
+ mlog(0, "fe->i_clusters = %u, new_i_clusters = %u, fe->i_size ="
+ "%"MLFu64"\n", fe->i_clusters, new_i_clusters, fe->i_size);
+
+ if (le32_to_cpu(fe->i_clusters) <= new_i_clusters) {
+ ocfs2_error(inode->i_sb, "Dinode %"MLFu64" has cluster count "
+ "%u and size %"MLFu64" whereas struct inode has "
+ "cluster count %u and size %llu which caused an "
+ "invalid truncate to %u clusters.",
+ le64_to_cpu(fe->i_blkno),
+ le32_to_cpu(fe->i_clusters),
+ le64_to_cpu(fe->i_size),
+ OCFS2_I(inode)->ip_clusters, i_size_read(inode),
+ new_i_clusters);
+ mlog_meta_lvb(ML_ERROR, &OCFS2_I(inode)->ip_meta_lockres);
+ status = -EIO;
+ goto bail;
+ }
+
+ *tc = kcalloc(1, sizeof(struct ocfs2_truncate_context), GFP_KERNEL);
+ if (!(*tc)) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ metadata_delete = 0;
+ if (fe->id2.i_list.l_tree_depth) {
+ /* If we have a tree, then the truncate may result in
+ * metadata deletes. Figure this out from the
+ * rightmost leaf block.*/
+ status = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
+ &last_eb_bh, OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+
+ brelse(last_eb_bh);
+ status = -EIO;
+ goto bail;
+ }
+ el = &(eb->h_list);
+ if (le32_to_cpu(el->l_recs[0].e_cpos) >= new_i_clusters)
+ metadata_delete = 1;
+ }
+
+ (*tc)->tc_last_eb_bh = last_eb_bh;
+
+ if (metadata_delete) {
+ mlog(0, "Will have to delete metadata for this trunc. "
+ "locking allocator.\n");
+ ext_alloc_inode = ocfs2_get_system_file_inode(osb, EXTENT_ALLOC_SYSTEM_INODE, 0);
+ if (!ext_alloc_inode) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ down(&ext_alloc_inode->i_sem);
+ (*tc)->tc_ext_alloc_inode = ext_alloc_inode;
+
+ status = ocfs2_meta_lock(ext_alloc_inode,
+ NULL,
+ &ext_alloc_bh,
+ 1);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ (*tc)->tc_ext_alloc_bh = ext_alloc_bh;
+ (*tc)->tc_ext_alloc_locked = 1;
+ }
+
+ status = 0;
+bail:
+ if (status < 0) {
+ if (*tc)
+ ocfs2_free_truncate_context(*tc);
+ *tc = NULL;
+ }
+ mlog_exit_void();
+ return status;
+}
+
+static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc)
+{
+ if (tc->tc_ext_alloc_inode) {
+ if (tc->tc_ext_alloc_locked)
+ ocfs2_meta_unlock(tc->tc_ext_alloc_inode, 1);
+
+ up(&tc->tc_ext_alloc_inode->i_sem);
+ iput(tc->tc_ext_alloc_inode);
+ }
+
+ if (tc->tc_ext_alloc_bh)
+ brelse(tc->tc_ext_alloc_bh);
+
+ if (tc->tc_last_eb_bh)
+ brelse(tc->tc_last_eb_bh);
+
+ kfree(tc);
+}
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * alloc.h
+ *
+ * Function prototypes
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef OCFS2_ALLOC_H
+#define OCFS2_ALLOC_H
+
+struct ocfs2_alloc_context;
+int ocfs2_insert_extent(struct ocfs2_super *osb,
+ struct ocfs2_journal_handle *handle,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ u64 blkno,
+ u32 new_clusters,
+ struct ocfs2_alloc_context *meta_ac);
+int ocfs2_num_free_extents(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct ocfs2_dinode *fe);
+/* how many new metadata chunks would an allocation need at maximum? */
+static inline int ocfs2_extend_meta_needed(struct ocfs2_dinode *fe)
+{
+ /*
+ * Rather than do all the work of determining how much we need
+ * (involves a ton of reads and locks), just ask for the
+ * maximal limit. That's a tree depth shift. So, one block for
+ * level of the tree (current l_tree_depth), one block for the
+ * new tree_depth==0 extent_block, and one block at the new
+ * top-of-the tree.
+ */
+ return le16_to_cpu(fe->id2.i_list.l_tree_depth) + 2;
+}
+
+int ocfs2_truncate_log_init(struct ocfs2_super *osb);
+void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
+void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
+ int cancel);
+int ocfs2_flush_truncate_log(struct ocfs2_super *osb);
+int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
+ int slot_num,
+ struct ocfs2_dinode **tl_copy);
+int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
+ struct ocfs2_dinode *tl_copy);
+
+struct ocfs2_truncate_context {
+ struct inode *tc_ext_alloc_inode;
+ struct buffer_head *tc_ext_alloc_bh;
+ int tc_ext_alloc_locked; /* is it cluster locked? */
+ /* these get destroyed once it's passed to ocfs2_commit_truncate. */
+ struct buffer_head *tc_last_eb_bh;
+};
+
+int ocfs2_prepare_truncate(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_truncate_context **tc);
+int ocfs2_commit_truncate(struct ocfs2_super *osb,
+ struct inode *inode,
+ struct buffer_head *fe_bh,
+ struct ocfs2_truncate_context *tc);
+
+#endif /* OCFS2_ALLOC_H */
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <asm/byteorder.h>
+
+#define MLOG_MASK_PREFIX ML_FILE_IO
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "aops.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "file.h"
+#include "inode.h"
+#include "journal.h"
+#include "super.h"
+#include "symlink.h"
+
+#include "buffer_head_io.h"
+
+static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int err = -EIO;
+ int status;
+ struct ocfs2_dinode *fe = NULL;
+ struct buffer_head *bh = NULL;
+ struct buffer_head *buffer_cache_bh = NULL;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ void *kaddr;
+
+ mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+ (unsigned long long)iblock, bh_result, create);
+
+ BUG_ON(ocfs2_inode_is_fast_symlink(inode));
+
+ if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
+ mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
+ (unsigned long long)iblock);
+ goto bail;
+ }
+
+ status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+ OCFS2_I(inode)->ip_blkno,
+ &bh, OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ fe = (struct ocfs2_dinode *) bh->b_data;
+
+ if (!OCFS2_IS_VALID_DINODE(fe)) {
+ mlog(ML_ERROR, "Invalid dinode #%"MLFu64": signature = %.*s\n",
+ fe->i_blkno, 7, fe->i_signature);
+ goto bail;
+ }
+
+ if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+ le32_to_cpu(fe->i_clusters))) {
+ mlog(ML_ERROR, "block offset is outside the allocated size: "
+ "%llu\n", (unsigned long long)iblock);
+ goto bail;
+ }
+
+ /* We don't use the page cache to create symlink data, so if
+ * need be, copy it over from the buffer cache. */
+ if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
+ u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
+ iblock;
+ buffer_cache_bh = sb_getblk(osb->sb, blkno);
+ if (!buffer_cache_bh) {
+ mlog(ML_ERROR, "couldn't getblock for symlink!\n");
+ goto bail;
+ }
+
+ /* we haven't locked out transactions, so a commit
+ * could've happened. Since we've got a reference on
+ * the bh, even if it commits while we're doing the
+ * copy, the data is still good. */
+ if (buffer_jbd(buffer_cache_bh)
+ && ocfs2_inode_is_new(inode)) {
+ kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
+ if (!kaddr) {
+ mlog(ML_ERROR, "couldn't kmap!\n");
+ goto bail;
+ }
+ memcpy(kaddr + (bh_result->b_size * iblock),
+ buffer_cache_bh->b_data,
+ bh_result->b_size);
+ kunmap_atomic(kaddr, KM_USER0);
+ set_buffer_uptodate(bh_result);
+ }
+ brelse(buffer_cache_bh);
+ }
+
+ map_bh(bh_result, inode->i_sb,
+ le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
+
+ err = 0;
+
+bail:
+ if (bh)
+ brelse(bh);
+
+ mlog_exit(err);
+ return err;
+}
+
+static int ocfs2_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int err = 0;
+ u64 p_blkno, past_eof;
+
+ mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+ (unsigned long long)iblock, bh_result, create);
+
+ if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
+ mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
+ inode, inode->i_ino);
+
+ if (S_ISLNK(inode->i_mode)) {
+ /* this always does I/O for some reason. */
+ err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
+ goto bail;
+ }
+
+ /* this can happen if another node truncs after our extend! */
+ spin_lock(&OCFS2_I(inode)->ip_lock);
+ if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+ OCFS2_I(inode)->ip_clusters))
+ err = -EIO;
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+ if (err)
+ goto bail;
+
+ err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+ NULL);
+ if (err) {
+ mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
+ "%"MLFu64", NULL)\n", err, inode,
+ (unsigned long long)iblock, p_blkno);
+ goto bail;
+ }
+
+ map_bh(bh_result, inode->i_sb, p_blkno);
+
+ if (bh_result->b_blocknr == 0) {
+ err = -EIO;
+ mlog(ML_ERROR, "iblock = %llu p_blkno = %"MLFu64" "
+ "blkno=(%"MLFu64")\n", (unsigned long long)iblock,
+ p_blkno, OCFS2_I(inode)->ip_blkno);
+ }
+
+ past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
+ mlog(0, "Inode %lu, past_eof = %"MLFu64"\n", inode->i_ino, past_eof);
+
+ if (create && (iblock >= past_eof))
+ set_buffer_new(bh_result);
+
+bail:
+ if (err < 0)
+ err = -EIO;
+
+ mlog_exit(err);
+ return err;
+}
+
+static int ocfs2_readpage(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
+ int ret, unlock = 1;
+
+ mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+ if (ret != 0) {
+ if (ret == AOP_TRUNCATED_PAGE)
+ unlock = 0;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ /*
+ * i_size might have just been updated as we grabed the meta lock. We
+ * might now be discovering a truncate that hit on another node.
+ * block_read_full_page->get_block freaks out if it is asked to read
+ * beyond the end of a file, so we check here. Callers
+ * (generic_file_read, fault->nopage) are clever enough to check i_size
+ * and notice that the page they just read isn't needed.
+ *
+ * XXX sys_readahead() seems to get that wrong?
+ */
+ if (start >= i_size_read(inode)) {
+ char *addr = kmap(page);
+ memset(addr, 0, PAGE_SIZE);
+ flush_dcache_page(page);
+ kunmap(page);
+ SetPageUptodate(page);
+ ret = 0;
+ goto out_alloc;
+ }
+
+ ret = ocfs2_data_lock_with_page(inode, 0, page);
+ if (ret != 0) {
+ if (ret == AOP_TRUNCATED_PAGE)
+ unlock = 0;
+ mlog_errno(ret);
+ goto out_alloc;
+ }
+
+ ret = block_read_full_page(page, ocfs2_get_block);
+ unlock = 0;
+
+ ocfs2_data_unlock(inode, 0);
+out_alloc:
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+ ocfs2_meta_unlock(inode, 0);
+out:
+ if (unlock)
+ unlock_page(page);
+ mlog_exit(ret);
+ return ret;
+}
+
+/* Note: Because we don't support holes, our allocation has
+ * already happened (allocation writes zeros to the file data)
+ * so we don't have to worry about ordered writes in
+ * ocfs2_writepage.
+ *
+ * ->writepage is called during the process of invalidating the page cache
+ * during blocked lock processing. It can't block on any cluster locks
+ * to during block mapping. It's relying on the fact that the block
+ * mapping can't have disappeared under the dirty pages that it is
+ * being asked to write back.
+ */
+static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+ int ret;
+
+ mlog_entry("(0x%p)\n", page);
+
+ ret = block_write_full_page(page, ocfs2_get_block, wbc);
+
+ mlog_exit(ret);
+
+ return ret;
+}
+
+/*
+ * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
+ * from loopback. It must be able to perform its own locking around
+ * ocfs2_get_block().
+ */
+int ocfs2_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ struct inode *inode = page->mapping->host;
+ int ret;
+
+ mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ret = block_prepare_write(page, from, to, ocfs2_get_block);
+
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ocfs2_meta_unlock(inode, 0);
+out:
+ mlog_exit(ret);
+ return ret;
+}
+
+/* Taken from ext3. We don't necessarily need the full blown
+ * functionality yet, but IMHO it's better to cut and paste the whole
+ * thing so we can avoid introducing our own bugs (and easily pick up
+ * their fixes when they happen) --Mark */
+static int walk_page_buffers( handle_t *handle,
+ struct buffer_head *head,
+ unsigned from,
+ unsigned to,
+ int *partial,
+ int (*fn)( handle_t *handle,
+ struct buffer_head *bh))
+{
+ struct buffer_head *bh;
+ unsigned block_start, block_end;
+ unsigned blocksize = head->b_size;
+ int err, ret = 0;
+ struct buffer_head *next;
+
+ for ( bh = head, block_start = 0;
+ ret == 0 && (bh != head || !block_start);
+ block_start = block_end, bh = next)
+ {
+ next = bh->b_this_page;
+ block_end = block_start + blocksize;
+ if (block_end <= from || block_start >= to) {
+ if (partial && !buffer_uptodate(bh))
+ *partial = 1;
+ continue;
+ }
+ err = (*fn)(handle, bh);
+ if (!ret)
+ ret = err;
+ }
+ return ret;
+}
+
+struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
+ struct page *page,
+ unsigned from,
+ unsigned to)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_journal_handle *handle = NULL;
+ int ret = 0;
+
+ handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
+ if (!handle) {
+ ret = -ENOMEM;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (ocfs2_should_order_data(inode)) {
+ ret = walk_page_buffers(handle->k_handle,
+ page_buffers(page),
+ from, to, NULL,
+ ocfs2_journal_dirty_data);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+out:
+ if (ret) {
+ if (handle)
+ ocfs2_commit_trans(handle);
+ handle = ERR_PTR(ret);
+ }
+ return handle;
+}
+
+static int ocfs2_commit_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ int ret, extending = 0, locklevel = 0;
+ loff_t new_i_size;
+ struct buffer_head *di_bh = NULL;
+ struct inode *inode = page->mapping->host;
+ struct ocfs2_journal_handle *handle = NULL;
+
+ mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+ /* NOTE: ocfs2_file_aio_write has ensured that it's safe for
+ * us to sample inode->i_size here without the metadata lock:
+ *
+ * 1) We're currently holding the inode alloc lock, so no
+ * nodes can change it underneath us.
+ *
+ * 2) We've had to take the metadata lock at least once
+ * already to check for extending writes, hence insuring
+ * that our current copy is also up to date.
+ */
+ new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ if (new_i_size > i_size_read(inode)) {
+ extending = 1;
+ locklevel = 1;
+ }
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_data_lock_with_page(inode, 1, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out_unlock_meta;
+ }
+
+ if (extending) {
+ handle = ocfs2_start_walk_page_trans(inode, page, from, to);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ handle = NULL;
+ goto out_unlock_data;
+ }
+
+ /* Mark our buffer early. We'd rather catch this error up here
+ * as opposed to after a successful commit_write which would
+ * require us to set back inode->i_size. */
+ ret = ocfs2_journal_access(handle, inode, di_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+ }
+
+ /* might update i_size */
+ ret = generic_commit_write(file, page, from, to);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ if (extending) {
+ loff_t size = (u64) i_size_read(inode);
+ struct ocfs2_dinode *di =
+ (struct ocfs2_dinode *)di_bh->b_data;
+
+ /* ocfs2_mark_inode_dirty is too heavy to use here. */
+ inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+ di->i_size = cpu_to_le64(size);
+ di->i_ctime = di->i_mtime =
+ cpu_to_le64(inode->i_mtime.tv_sec);
+ di->i_ctime_nsec = di->i_mtime_nsec =
+ cpu_to_le32(inode->i_mtime.tv_nsec);
+
+ ret = ocfs2_journal_dirty(handle, di_bh);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+ }
+
+ BUG_ON(extending && (i_size_read(inode) != new_i_size));
+
+out_commit:
+ if (handle)
+ ocfs2_commit_trans(handle);
+out_unlock_data:
+ ocfs2_data_unlock(inode, 1);
+out_unlock_meta:
+ ocfs2_meta_unlock(inode, locklevel);
+out:
+ if (di_bh)
+ brelse(di_bh);
+
+ mlog_exit(ret);
+ return ret;
+}
+
+static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
+{
+ sector_t status;
+ u64 p_blkno = 0;
+ int err = 0;
+ struct inode *inode = mapping->host;
+
+ mlog_entry("(block = %llu)\n", (unsigned long long)block);
+
+ /* We don't need to lock journal system files, since they aren't
+ * accessed concurrently from multiple nodes.
+ */
+ if (!INODE_JOURNAL(inode)) {
+ err = ocfs2_meta_lock(inode, NULL, NULL, 0);
+ if (err) {
+ if (err != -ENOENT)
+ mlog_errno(err);
+ goto bail;
+ }
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+ }
+
+ err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
+ NULL);
+
+ if (!INODE_JOURNAL(inode)) {
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+ ocfs2_meta_unlock(inode, 0);
+ }
+
+ if (err) {
+ mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
+ (unsigned long long)block);
+ mlog_errno(err);
+ goto bail;
+ }
+
+
+bail:
+ status = err ? 0 : p_blkno;
+
+ mlog_exit((int)status);
+
+ return status;
+}
+
+/*
+ * TODO: Make this into a generic get_blocks function.
+ *
+ * From do_direct_io in direct-io.c:
+ * "So what we do is to permit the ->get_blocks function to populate
+ * bh.b_size with the size of IO which is permitted at this offset and
+ * this i_blkbits."
+ *
+ * This function is called directly from get_more_blocks in direct-io.c.
+ *
+ * called like this: dio->get_blocks(dio->inode, fs_startblk,
+ * fs_count, map_bh, dio->rw == WRITE);
+ */
+static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
+ unsigned long max_blocks,
+ struct buffer_head *bh_result, int create)
+{
+ int ret;
+ u64 vbo_max; /* file offset, max_blocks from iblock */
+ u64 p_blkno;
+ int contig_blocks;
+ unsigned char blocksize_bits;
+
+ if (!inode || !bh_result) {
+ mlog(ML_ERROR, "inode or bh_result is null\n");
+ return -EIO;
+ }
+
+ blocksize_bits = inode->i_sb->s_blocksize_bits;
+
+ /* This function won't even be called if the request isn't all
+ * nicely aligned and of the right size, so there's no need
+ * for us to check any of that. */
+
+ vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;
+
+ spin_lock(&OCFS2_I(inode)->ip_lock);
+ if ((iblock + max_blocks) >
+ ocfs2_clusters_to_blocks(inode->i_sb,
+ OCFS2_I(inode)->ip_clusters)) {
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+ ret = -EIO;
+ goto bail;
+ }
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+
+ /* This figures out the size of the next contiguous block, and
+ * our logical offset */
+ ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+ &contig_blocks);
+ if (ret) {
+ mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
+ (unsigned long long)iblock);
+ ret = -EIO;
+ goto bail;
+ }
+
+ map_bh(bh_result, inode->i_sb, p_blkno);
+
+ /* make sure we don't map more than max_blocks blocks here as
+ that's all the kernel will handle at this point. */
+ if (max_blocks < contig_blocks)
+ contig_blocks = max_blocks;
+ bh_result->b_size = contig_blocks << blocksize_bits;
+bail:
+ return ret;
+}
+
+/*
+ * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
+ * particularly interested in the aio/dio case. Like the core uses
+ * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
+ * truncation on another.
+ */
+static void ocfs2_dio_end_io(struct kiocb *iocb,
+ loff_t offset,
+ ssize_t bytes,
+ void *private)
+{
+ struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
+
+ /* this io's submitter should not have unlocked this before we could */
+ BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
+ ocfs2_iocb_clear_rw_locked(iocb);
+ up_read(&inode->i_alloc_sem);
+ ocfs2_rw_unlock(inode, 0);
+}
+
+static ssize_t ocfs2_direct_IO(int rw,
+ struct kiocb *iocb,
+ const struct iovec *iov,
+ loff_t offset,
+ unsigned long nr_segs)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_dentry->d_inode->i_mapping->host;
+ int ret;
+
+ mlog_entry_void();
+ ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
+ inode->i_sb->s_bdev, iov, offset,
+ nr_segs,
+ ocfs2_direct_IO_get_blocks,
+ ocfs2_dio_end_io);
+ mlog_exit(ret);
+ return ret;
+}
+
+struct address_space_operations ocfs2_aops = {
+ .readpage = ocfs2_readpage,
+ .writepage = ocfs2_writepage,
+ .prepare_write = ocfs2_prepare_write,
+ .commit_write = ocfs2_commit_write,
+ .bmap = ocfs2_bmap,
+ .sync_page = block_sync_page,
+ .direct_IO = ocfs2_direct_IO
+};
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2002, 2004, 2005 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef OCFS2_AOPS_H
+#define OCFS2_AOPS_H
+
+int ocfs2_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to);
+
+struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
+ struct page *page,
+ unsigned from,
+ unsigned to);
+
+/* all ocfs2_dio_end_io()'s fault */
+#define ocfs2_iocb_is_rw_locked(iocb) \
+ test_bit(0, (unsigned long *)&iocb->private)
+#define ocfs2_iocb_set_rw_locked(iocb) \
+ set_bit(0, (unsigned long *)&iocb->private)
+#define ocfs2_iocb_clear_rw_locked(iocb) \
+ clear_bit(0, (unsigned long *)&iocb->private)
+
+#endif /* OCFS2_FILE_H */
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * io.c
+ *
+ * Buffer cache handling
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "inode.h"
+#include "journal.h"
+#include "uptodate.h"
+
+#include "buffer_head_io.h"
+
+int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
+ struct inode *inode)
+{
+ int ret = 0;
+
+ mlog_entry("(bh->b_blocknr = %llu, inode=%p)\n",
+ (unsigned long long)bh->b_blocknr, inode);
+
+ BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
+ BUG_ON(buffer_jbd(bh));
+
+ /* No need to check for a soft readonly file system here. non
+ * journalled writes are only ever done on system files which
+ * can get modified during recovery even if read-only. */
+ if (ocfs2_is_hard_readonly(osb)) {
+ ret = -EROFS;
+ goto out;
+ }
+
+ down(&OCFS2_I(inode)->ip_io_sem);
+
+ lock_buffer(bh);
+ set_buffer_uptodate(bh);
+
+ /* remove from dirty list before I/O. */
+ clear_buffer_dirty(bh);
+
+ get_bh(bh); /* for end_buffer_write_sync() */
+ bh->b_end_io = end_buffer_write_sync;
+ submit_bh(WRITE, bh);
+
+ wait_on_buffer(bh);
+
+ if (buffer_uptodate(bh)) {
+ ocfs2_set_buffer_uptodate(inode, bh);
+ } else {
+ /* We don't need to remove the clustered uptodate
+ * information for this bh as it's not marked locally
+ * uptodate. */
+ ret = -EIO;
+ brelse(bh);
+ }
+
+ up(&OCFS2_I(inode)->ip_io_sem);
+out:
+ mlog_exit(ret);
+ return ret;
+}
+
+int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
+ struct buffer_head *bhs[], int flags,
+ struct inode *inode)
+{
+ int status = 0;
+ struct super_block *sb;
+ int i, ignore_cache = 0;
+ struct buffer_head *bh;
+
+ mlog_entry("(block=(%"MLFu64"), nr=(%d), flags=%d, inode=%p)\n",
+ block, nr, flags, inode);
+
+ if (osb == NULL || osb->sb == NULL || bhs == NULL) {
+ status = -EINVAL;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ if (nr < 0) {
+ mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
+ status = -EINVAL;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ if (nr == 0) {
+ mlog(ML_BH_IO, "No buffers will be read!\n");
+ status = 0;
+ goto bail;
+ }
+
+ sb = osb->sb;
+
+ if (flags & OCFS2_BH_CACHED && !inode)
+ flags &= ~OCFS2_BH_CACHED;
+
+ if (inode)
+ down(&OCFS2_I(inode)->ip_io_sem);
+ for (i = 0 ; i < nr ; i++) {
+ if (bhs[i] == NULL) {
+ bhs[i] = sb_getblk(sb, block++);
+ if (bhs[i] == NULL) {
+ if (inode)
+ up(&OCFS2_I(inode)->ip_io_sem);
+ status = -EIO;
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+ bh = bhs[i];
+ ignore_cache = 0;
+
+ if (flags & OCFS2_BH_CACHED &&
+ !ocfs2_buffer_uptodate(inode, bh)) {
+ mlog(ML_UPTODATE,
+ "bh (%llu), inode %"MLFu64" not uptodate\n",
+ (unsigned long long)bh->b_blocknr,
+ OCFS2_I(inode)->ip_blkno);
+ ignore_cache = 1;
+ }
+
+ /* XXX: Can we ever get this and *not* have the cached
+ * flag set? */
+ if (buffer_jbd(bh)) {
+ if (!(flags & OCFS2_BH_CACHED) || ignore_cache)
+ mlog(ML_BH_IO, "trying to sync read a jbd "
+ "managed bh (blocknr = %llu)\n",
+ (unsigned long long)bh->b_blocknr);
+ continue;
+ }
+
+ if (!(flags & OCFS2_BH_CACHED) || ignore_cache) {
+ if (buffer_dirty(bh)) {
+ /* This should probably be a BUG, or
+ * at least return an error. */
+ mlog(ML_BH_IO, "asking me to sync read a dirty "
+ "buffer! (blocknr = %llu)\n",
+ (unsigned long long)bh->b_blocknr);
+ continue;
+ }
+
+ lock_buffer(bh);
+ if (buffer_jbd(bh)) {
+#ifdef CATCH_BH_JBD_RACES
+ mlog(ML_ERROR, "block %llu had the JBD bit set "
+ "while I was in lock_buffer!",
+ (unsigned long long)bh->b_blocknr);
+ BUG();
+#else
+ unlock_buffer(bh);
+ continue;
+#endif
+ }
+ clear_buffer_uptodate(bh);
+ get_bh(bh); /* for end_buffer_read_sync() */
+ bh->b_end_io = end_buffer_read_sync;
+ if (flags & OCFS2_BH_READAHEAD)
+ submit_bh(READA, bh);
+ else
+ submit_bh(READ, bh);
+ continue;
+ }
+ }
+
+ status = 0;
+
+ for (i = (nr - 1); i >= 0; i--) {
+ bh = bhs[i];
+
+ /* We know this can't have changed as we hold the
+ * inode sem. Avoid doing any work on the bh if the
+ * journal has it. */
+ if (!buffer_jbd(bh))
+ wait_on_buffer(bh);
+
+ if (!buffer_uptodate(bh)) {
+ /* Status won't be cleared from here on out,
+ * so we can safely record this and loop back
+ * to cleanup the other buffers. Don't need to
+ * remove the clustered uptodate information
+ * for this bh as it's not marked locally
+ * uptodate. */
+ status = -EIO;
+ brelse(bh);
+ bhs[i] = NULL;
+ continue;
+ }
+
+ if (inode)
+ ocfs2_set_buffer_uptodate(inode, bh);
+ }
+ if (inode)
+ up(&OCFS2_I(inode)->ip_io_sem);
+
+ mlog(ML_BH_IO, "block=(%"MLFu64"), nr=(%d), cached=%s\n", block, nr,
+ (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes");
+
+bail:
+
+ mlog_exit(status);
+ return status;
+}
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * ocfs2_buffer_head.h
+ *
+ * Buffer cache handling functions defined
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef OCFS2_BUFFER_HEAD_IO_H
+#define OCFS2_BUFFER_HEAD_IO_H
+
+#include <linux/buffer_head.h>
+
+void ocfs2_end_buffer_io_sync(struct buffer_head *bh,
+ int uptodate);
+
+static inline int ocfs2_read_block(struct ocfs2_super *osb,
+ u64 off,
+ struct buffer_head **bh,
+ int flags,
+ struct inode *inode);
+
+int ocfs2_write_block(struct ocfs2_super *osb,
+ struct buffer_head *bh,
+ struct inode *inode);
+int ocfs2_read_blocks(struct ocfs2_super *osb,
+ u64 block,
+ int nr,
+ struct buffer_head *bhs[],
+ int flags,
+ struct inode *inode);
+
+
+#define OCFS2_BH_CACHED 1
+#define OCFS2_BH_READAHEAD 8 /* use this to pass READA down to submit_bh */
+
+static inline int ocfs2_read_block(struct ocfs2_super * osb, u64 off,
+ struct buffer_head **bh, int flags,
+ struct inode *inode)
+{
+ int status = 0;
+
+ if (bh == NULL) {
+ printk("ocfs2: bh == NULL\n");
+ status = -EINVAL;
+ goto bail;
+ }
+
+ status = ocfs2_read_blocks(osb, off, 1, bh,
+ flags, inode);
+
+bail:
+ return status;
+}
+
+#endif /* OCFS2_BUFFER_HEAD_IO_H */
--- /dev/null
+obj-$(CONFIG_OCFS2_FS) += ocfs2_nodemanager.o
+
+ocfs2_nodemanager-objs := heartbeat.o masklog.o sys.o nodemanager.o \
+ quorum.o tcp.o ver.o
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2005 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef OCFS2_CLUSTER_ENDIAN_H
+#define OCFS2_CLUSTER_ENDIAN_H
+
+static inline void be32_add_cpu(__be32 *var, u32 val)
+{
+ *var = cpu_to_be32(be32_to_cpu(*var) + val);
+}
+
+#endif /* OCFS2_CLUSTER_ENDIAN_H */
--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2004, 2005 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/kthread.h>
+#include <linux/configfs.h>
+#include <linux/random.h>
+#include <linux/crc32.h>
+#include <linux/time.h>
+
+#include "heartbeat.h"
+#include "tcp.h"
+#include "nodemanager.h"
+#include "quorum.h"
+
+#include "masklog.h"
+
+
+/*
+ * The first heartbeat pass had one global thread that would serialize all hb
+ * callback calls. This global serializing sem should only be removed once
+ * we've made sure that all callees can deal with being called concurrently
+ * from multiple hb region threads.
+ */
+static DECLARE_RWSEM(o2hb_callback_sem);
+
+/*
+ * multiple hb threads are watching multiple regions. A node is live
+ * whenever any of the threads sees activity from the node in its region.
+ */
+static spinlock_t o2hb_live_lock = SPIN_LOCK_UNLOCKED;
+static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
+static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
+static LIST_HEAD(o2hb_node_events);
+static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
+
+static LIST_HEAD(o2hb_all_regions);
+
+static struct o2hb_callback {
+ struct list_head list;
+} o2hb_callbacks[O2HB_NUM_CB];
+
+static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
+
+#define O2HB_DEFAULT_BLOCK_BITS 9
+
+unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
+
+/* Only sets a new threshold if there are no active regions.
+ *
+ * No locking or otherwise interesting code is required for reading
+ * o2hb_dead_threshold as it can't change once regions are active and
+ * it's not interesting to anyone until then anyway. */
+static void o2hb_dead_threshold_set(unsigned int threshold)
+{
+ if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
+ spin_lock(&o2hb_live_lock);
+ if (list_empty(&o2hb_all_regions))
+ o2hb_dead_threshold = threshold;
+ spin_unlock(&o2hb_live_lock);
+ }
+}
+
+struct o2hb_node_event {
+ struct list_head hn_item;
+ enum o2hb_callback_type hn_event_type;
+ struct o2nm_node *hn_node;
+ int hn_node_num;
+};
+
+struct o2hb_disk_slot {
+ struct o2hb_disk_heartbeat_block *ds_raw_block;
+ u8 ds_node_num;
+ u64 ds_last_time;
+ u64 ds_last_generation;
+ u16 ds_equal_samples;
+ u16 ds_changed_samples;
+ struct list_head ds_live_item;
+};
+
+/* each thread owns a region.. when we're asked to tear down the region
+ * we ask the thread to stop, who cleans up the region */
+struct o2hb_region {
+ struct config_item hr_item;
+
+ struct list_head hr_all_item;
+ unsigned hr_unclean_stop:1;
+
+ /* protected by the hr_callback_sem */
+ struct task_struct *hr_task;
+
+ unsigned int hr_blocks;
+ unsigned long long hr_start_block;
+
+ unsigned int hr_block_bits;
+ unsigned int hr_block_bytes;
+
+ unsigned int hr_slots_per_page;
+ unsigned int hr_num_pages;
+
+ struct page **hr_slot_data;
+ struct block_device *hr_bdev;
+ struct o2hb_disk_slot *hr_slots;
+
+ /* let the person setting up hb wait for it to return until it
+ * has reached a 'steady' state. This will be fixed when we have
+ * a more complete api that doesn't lead to this sort of fragility. */
+ atomic_t hr_steady_iterations;
+
+ char hr_dev_name[BDEVNAME_SIZE];
+
+ unsigned int hr_timeout_ms;
+
+ /* randomized as the region goes up and down so that a node
+ * recognizes a node going up and down in one iteration */
+ u64 hr_generation;
+
+ struct work_struct hr_write_timeout_work;
+ unsigned long hr_last_timeout_start;
+
+ /* Used during o2hb_check_slot to hold a copy of the block
+ * being checked because we temporarily have to zero out the
+ * crc field. */
+ struct o2hb_disk_heartbeat_block *hr_tmp_block;
+};
+
+struct o2hb_bio_wait_ctxt {
+ atomic_t wc_num_reqs;
+ struct completion wc_io_complete;
+};
+
+static void o2hb_write_timeout(void *arg)
+{
+ struct o2hb_region *reg = arg;
+
+ mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
+ "milliseconds\n", reg->hr_dev_name,
+ jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
+ o2quo_disk_timeout();
+}
+
+static void o2hb_arm_write_timeout(struct o2hb_region *reg)
+{
+ mlog(0, "Queue write timeout for %u ms\n", O2HB_MAX_WRITE_TIMEOUT_MS);
+
+ cancel_delayed_work(®->hr_write_timeout_work);
+ reg->hr_last_timeout_start = jiffies;
+ schedule_delayed_work(®->hr_write_timeout_work,
+ msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
+}
+
+static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
+{
+ cancel_delayed_work(®->hr_write_timeout_work);
+ flush_scheduled_work();
+}
+
+static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc,
+ unsigned int num_ios)
+{
+ atomic_set(&wc->wc_num_reqs, num_ios);
+ init_completion(&wc->wc_io_complete);
+}
+
+/* Used in error paths too */
+static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
+ unsigned int num)
+{
+ /* sadly atomic_sub_and_test() isn't available on all platforms. The
+ * good news is that the fast path only completes one at a time */
+ while(num--) {
+ if (atomic_dec_and_test(&wc->wc_num_reqs)) {
+ BUG_ON(num > 0);
+ complete(&wc->wc_io_complete);
+ }
+ }
+}
+
+static void o2hb_wait_on_io(struct o2hb_region *reg,
+ struct o2hb_bio_wait_ctxt *wc)
+{
+ struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping;
+
+ blk_run_address_space(mapping);
+
+ wait_for_completion(&wc->wc_io_complete);
+}
+
+static int o2hb_bio_end_io(struct bio *bio,
+ unsigned int bytes_done,
+ int error)
+{
+ struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
+
+ if (error)
+ mlog(ML_ERROR, "IO Error %d\n", error);
+
+ if (bio->bi_size)
+ return 1;
+
+ o2hb_bio_wait_dec(wc, 1);
+ return 0;
+}
+
+/* Setup a Bio to cover I/O against num_slots slots starting at
+ * start_slot. */
+static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
+ struct o2hb_bio_wait_ctxt *wc,
+ unsigned int start_slot,
+ unsigned int num_slots)
+{
+ int i, nr_vecs, len, first_page, last_page;
+ unsigned int vec_len, vec_start;
+ unsigned int bits = reg->hr_block_bits;
+ unsigned int spp = reg->hr_slots_per_page;
+ struct bio *bio;
+ struct page *page;
+
+ nr_vecs = (num_slots + spp - 1) / spp;
+
+ /* Testing has shown this allocation to take long enough under
+ * GFP_KERNEL that the local node can get fenced. It would be
+ * nicest if we could pre-allocate these bios and avoid this
+ * all together. */
+ bio = bio_alloc(GFP_ATOMIC, nr_vecs);
+ if (!bio) {
+ mlog(ML_ERROR, "Could not alloc slots BIO!\n");
+ bio = ERR_PTR(-ENOMEM);
+ goto bail;
+ }
+
+ /* Must put everything in 512 byte sectors for the bio... */
+ bio->bi_sector = (reg->hr_start_block + start_slot) << (bits - 9);
+ bio->bi_bdev = reg->hr_bdev;
+ bio->bi_private = wc;
+ bio->bi_end_io = o2hb_bio_end_io;
+
+ first_page = start_slot / spp;
+ last_page = first_page + nr_vecs;
+ vec_start = (start_slot << bits) % PAGE_CACHE_SIZE;
+ for(i = first_page; i < last_page; i++) {
+ page = reg->hr_slot_data[i];
+
+ vec_len = PAGE_CACHE_SIZE;
+ /* last page might be short */
+ if (((i + 1) * spp) > (start_slot + num_slots))
+ vec_len = ((num_slots + start_slot) % spp) << bits;
+ vec_len -= vec_start;
+
+ mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
+ i, vec_len, vec_start);
+
+ len = bio_add_page(bio, page, vec_len, vec_start);
+ if (len != vec_len) {
+ bio_put(bio);
+ bio = ERR_PTR(-EIO);
+
+ mlog(ML_ERROR, "Error adding page to bio i = %d, "
+ "vec_len = %u, len = %d\n, start = %u\n",
+ i, vec_len, len, vec_start);
+ goto bail;
+ }
+
+ vec_start = 0;
+ }
+
+bail:
+ return bio;
+}
+
+/*
+ * Compute the maximum number of sectors the bdev can handle in one bio,
+ * as a power of two.
+ *
+ * Stolen from oracleasm, thanks Joel!
+ */
+static int compute_max_sectors(struct block_device *bdev)
+{
+ int max_pages, max_sectors, pow_two_sectors;
+
+ struct request_queue *q;
+
+ q = bdev_get_queue(bdev);
+ max_pages = q->max_sectors >> (PAGE_SHIFT - 9);
+ if (max_pages > BIO_MAX_PAGES)
+ max_pages = BIO_MAX_PAGES;
+ if (max_pages > q->max_phys_segments)
+ max_pages = q->max_phys_segments;
+ if (max_pages > q->max_hw_segments)
+ max_pages = q->max_hw_segments;
+ max_pages--; /* Handle I/Os that straddle a page */
+
+ max_sectors = max_pages << (PAGE_SHIFT - 9);
+
+ /* Why is fls() 1-based???? */
+ pow_two_sectors = 1 << (fls(max_sectors) - 1);
+
+ return pow_two_sectors;
+}
+
+static inline void o2hb_compute_request_limits(struct o2hb_region *reg,
+ unsigned int num_slots,
+ unsigned int *num_bios,
+ unsigned int *slots_per_bio)
+{
+ unsigned int max_sectors, io_sectors;
+
+ max_sectors = compute_max_sectors(reg->hr_bdev);
+
+ io_sectors = num_slots << (reg->hr_block_bits - 9);
+
+ *num_bios = (io_sectors + max_sectors - 1) / max_sectors;
+ *slots_per_bio = max_sectors >> (reg->hr_block_bits - 9);
+
+ mlog(ML_HB_BIO, "My io size is %u sectors for %u slots. This "
+ "device can handle %u sectors of I/O\n", io_sectors, num_slots,
+ max_sectors);
+ mlog(ML_HB_BIO, "Will need %u bios holding %u slots each\n",
+ *num_bios, *slots_per_bio);
+}
+
+static int o2hb_read_slots(struct o2hb_region *reg,
+ unsigned int max_slots)
+{
+ unsigned int num_bios, slots_per_bio, start_slot, num_slots;
+ int i, status;
+ struct o2hb_bio_wait_ctxt wc;
+ struct bio **bios;
+ struct bio *bio;
+
+ o2hb_compute_request_limits(reg, max_slots, &num_bios, &slots_per_bio);
+
+ bios = kcalloc(num_bios, sizeof(struct bio *), GFP_KERNEL);
+ if (!bios) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ return status;
+ }
+
+ o2hb_bio_wait_init(&wc, num_bios);
+
+ num_slots = slots_per_bio;
+ for(i = 0; i < num_bios; i++) {
+ start_slot = i * slots_per_bio;
+
+ /* adjust num_slots at last bio */
+ if (max_slots < (start_slot + num_slots))
+ num_slots = max_slots - start_slot;
+
+ bio = o2hb_setup_one_bio(reg, &wc, start_slot, num_slots);
+ if (IS_ERR(bio)) {
+ o2hb_bio_wait_dec(&wc, num_bios - i);
+
+ status = PTR_ERR(bio);
+ mlog_errno(status);
+ goto bail_and_wait;
+ }
+ bios[i] = bio;
+
+ submit_bio(READ, bio);
+ }
+
+ status = 0;
+
+bail_and_wait:
+ o2hb_wait_on_io(reg, &wc);
+
+ if (bios) {
+ for(i = 0; i < num_bios; i++)
+ if (bios[i])
+ bio_put(bios[i]);
+ kfree(bios);
+ }
+
+ return status;
+}
+
+static int o2hb_issue_node_write(struct o2hb_region *reg,
+ struct bio **write_bio,
+ struct o2hb_bio_wait_ctxt *write_wc)
+{
+ int status;
+ unsigned int slot;
+ struct bio *bio;
+
+ o2hb_bio_wait_init(write_wc, 1);
+
+ slot = o2nm_this_node();
+
+ bio = o2hb_setup_one_bio(reg, write_wc, slot, 1);
+ if (IS_ERR(bio)) {
+ status = PTR_ERR(bio);
+ mlog_errno(status);
+ goto bail;
+ }
+
+ submit_bio(WRITE, bio);
+
+ *write_bio = bio;
+ status = 0;
+bail:
+ return status;
+}
+
+static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
+ struct o2hb_disk_heartbeat_block *hb_block)
+{
+ __le32 old_cksum;
+ u32 ret;
+
+ /* We want to compute the block crc with a 0 value in the
+ * hb_cksum field. Save it off here and replace after the
+ * crc. */
+ old_cksum = hb_block->hb_cksum;
+ hb_block->hb_cksum = 0;
+
+ ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
+
+ hb_block->hb_cksum = old_cksum;
+
+ return ret;
+}
+
+static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
+{
+ mlog(ML_ERROR, "Dump slot information: seq = 0x%"MLFx64", node = %u, "
+ "cksum = 0x%x, generation 0x%"MLFx64"\n",
+ le64_to_cpu(hb_block->hb_seq), hb_block->hb_node,
+ le32_to_cpu(hb_block->hb_cksum),
+ le64_to_cpu(hb_block->hb_generation));
+}
+
+static int o2hb_verify_crc(struct o2hb_region *reg,
+ struct o2hb_disk_heartbeat_block *hb_block)
+{
+ u32 read, computed;
+
+ read = le32_to_cpu(hb_block->hb_cksum);
+ computed = o2hb_compute_block_crc_le(reg, hb_block);
+
+ return read == computed;
+}
+
+/* We want to make sure that nobody is heartbeating on top of us --
+ * this will help detect an invalid configuration. */
+static int o2hb_check_last_timestamp(struct o2hb_region *reg)
+{
+ int node_num, ret;
+ struct o2hb_disk_slot *slot;
+ struct o2hb_disk_heartbeat_block *hb_block;
+
+ node_num = o2nm_this_node();
+
+ ret = 1;
+ slot = ®->hr_slots[node_num];
+ /* Don't check on our 1st timestamp */
+ if (slot->ds_last_time) {
+ hb_block = slot->ds_raw_block;
+
+ if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static inline void o2hb_prepare_block(struct o2hb_region *reg,
+ u64 generation)
+{
+ int node_num;
+ u64 cputime;
+ struct o2hb_disk_slot *slot;
+ struct o2hb_disk_heartbeat_block *hb_block;
+
+ node_num = o2nm_this_node();
+ slot = ®->hr_slots[node_num];
+
+ hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
+ memset(hb_block, 0, reg->hr_block_bytes);
+ /* TODO: time stuff */
+ cputime = CURRENT_TIME.tv_sec;
+ if (!cputime)
+ cputime = 1;
+
+ hb_block->hb_seq = cpu_to_le64(cputime);
+ hb_block->hb_node = node_num;
+ hb_block->hb_generation = cpu_to_le64(generation);
+
+ /* This step must always happen last! */
+ hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
+ hb_block));
+
+ mlog(ML_HB_BIO, "our node generation = 0x%"MLFx64", cksum = 0x%x\n",
+ cpu_to_le64(generation), le32_to_cpu(hb_block->hb_cksum));
+}
+
+static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
+ struct o2nm_node *node,
+ int idx)
+{
+ struct list_head *iter;
+ struct o2hb_callback_func *f;
+
+ list_for_each(iter, &hbcall->list) {
+ f = list_entry(iter, struct o2hb_callback_func, hc_item);
+ mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
+ (f->hc_func)(node, idx, f->hc_data);
+ }
+}
+
+/* Will run the list in order until we process the passed event */
+static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
+{
+ int empty;
+ struct o2hb_callback *hbcall;
+ struct o2hb_node_event *event;
+
+ spin_lock(&o2hb_live_lock);
+ empty = list_empty(&queued_event->hn_item);
+ spin_unlock(&o2hb_live_lock);
+ if (empty)
+ return;
+
+ /* Holding callback sem assures we don't alter the callback
+ * lists when doing this, and serializes ourselves with other
+ * processes wanting callbacks. */
+ down_write(&o2hb_callback_sem);
+
+ spin_lock(&o2hb_live_lock);
+ while (!list_empty(&o2hb_node_events)
+ && !list_empty(&queued_event->hn_item)) {
+ event = list_entry(o2hb_node_events.next,
+ struct o2hb_node_event,
+ hn_item);
+ list_del_init(&event->hn_item);
+ spin_unlock(&o2hb_live_lock);
+
+ mlog(ML_HEARTBEAT, "Node %s event for %d\n",
+ event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
+ event->hn_node_num);
+
+ hbcall = hbcall_from_type(event->hn_event_type);
+
+ /* We should *never* have gotten on to the list with a
+ * bad type... This isn't something that we should try
+ * to recover from. */
+ BUG_ON(IS_ERR(hbcall));
+
+ o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
+
+ spin_lock(&o2hb_live_lock);
+ }
+ spin_unlock(&o2hb_live_lock);
+
+ up_write(&o2hb_callback_sem);
+}
+
+static void o2hb_queue_node_event(struct o2hb_node_event *event,
+ enum o2hb_callback_type type,
+ struct o2nm_node *node,
+ int node_num)
+{
+ assert_spin_locked(&o2hb_live_lock);
+
+ event->hn_event_type = type;
+ event->hn_node = node;
+ event->hn_node_num = node_num;
+
+ mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
+ type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
+
+ list_add_tail(&event->hn_item, &o2hb_node_events);
+}
+
+static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
+{
+ struct o2hb_node_event event =
+ { .hn_item = LIST_HEAD_INIT(event.hn_item), };
+ struct o2nm_node *node;
+
+ node = o2nm_get_node_by_num(slot->ds_node_num);
+ if (!node)
+ return;
+
+ spin_lock(&o2hb_live_lock);
+ if (!list_empty(&slot->ds_live_item)) {
+ mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
+ slot->ds_node_num);
+
+ list_del_init(&slot->ds_live_item);
+
+ if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
+ clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
+
+ o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
+ slot->ds_node_num);
+ }
+ }
+ spin_unlock(&o2hb_live_lock);
+
+ o2hb_run_event_list(&event);
+
+ o2nm_node_put(node);
+}
+
+static int o2hb_check_slot(struct o2hb_region *reg,
+ struct o2hb_disk_slot *slot)
+{
+ int changed = 0, gen_changed = 0;
+ struct o2hb_node_event event =
+ { .hn_item = LIST_HEAD_INIT(event.hn_item), };
+ struct o2nm_node *node;
+ struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
+ u64 cputime;
+
+ memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
+
+ /* Is this correct? Do we assume that the node doesn't exist
+ * if we're not configured for him? */
+ node = o2nm_get_node_by_num(slot->ds_node_num);
+ if (!node)
+ return 0;
+
+ if (!o2hb_verify_crc(reg, hb_block)) {
+ /* all paths from here will drop o2hb_live_lock for
+ * us. */
+ spin_lock(&o2hb_live_lock);
+
+ /* Don't print an error on the console in this case -
+ * a freshly formatted heartbeat area will not have a
+ * crc set on it. */
+ if (list_empty(&slot->ds_live_item))
+ goto out;
+
+ /* The node is live but pushed out a bad crc. We
+ * consider it a transient miss but don't populate any
+ * other values as they may be junk. */
+ mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
+ slot->ds_node_num, reg->hr_dev_name);
+ o2hb_dump_slot(hb_block);
+
+ slot->ds_equal_samples++;
+ goto fire_callbacks;
+ }
+
+ /* we don't care if these wrap.. the state transitions below
+ * clear at the right places */
+ cputime = le64_to_cpu(hb_block->hb_seq);
+ if (slot->ds_last_time != cputime)
+ slot->ds_changed_samples++;
+ else
+ slot->ds_equal_samples++;
+ slot->ds_last_time = cputime;
+
+ /* The node changed heartbeat generations. We assume this to
+ * mean it dropped off but came back before we timed out. We
+ * want to consider it down for the time being but don't want
+ * to lose any changed_samples state we might build up to
+ * considering it live again. */
+ if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
+ gen_changed = 1;
+ slot->ds_equal_samples = 0;
+ mlog(ML_HEARTBEAT, "Node %d changed generation (0x%"MLFx64" "
+ "to 0x%"MLFx64")\n", slot->ds_node_num,
+ slot->ds_last_generation,
+ le64_to_cpu(hb_block->hb_generation));
+ }
+
+ slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
+
+ mlog(ML_HEARTBEAT, "Slot %d gen 0x%"MLFx64" cksum 0x%x "
+ "seq %"MLFu64" last %"MLFu64" changed %u equal %u\n",
+ slot->ds_node_num, slot->ds_last_generation,
+ le32_to_cpu(hb_block->hb_cksum), le64_to_cpu(hb_block->hb_seq),
+ slot->ds_last_time, slot->ds_changed_samples,
+ slot->ds_equal_samples);
+
+ spin_lock(&o2hb_live_lock);
+
+fire_callbacks:
+ /* dead nodes only come to life after some number of
+ * changes at any time during their dead time */
+ if (list_empty(&slot->ds_live_item) &&
+ slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
+ mlog(ML_HEARTBEAT, "Node %d (id 0x%"MLFx64") joined my "
+ "region\n", slot->ds_node_num, slot->ds_last_generation);
+
+ /* first on the list generates a callback */
+ if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
+ set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
+
+ o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
+ slot->ds_node_num);
+
+ changed = 1;
+ }
+
+ list_add_tail(&slot->ds_live_item,
+ &o2hb_live_slots[slot->ds_node_num]);
+
+ slot->ds_equal_samples = 0;
+ goto out;
+ }
+
+ /* if the list is dead, we're done.. */
+ if (list_empty(&slot->ds_live_item))
+ goto out;
+
+ /* live nodes only go dead after enough consequtive missed
+ * samples.. reset the missed counter whenever we see
+ * activity */
+ if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
+ mlog(ML_HEARTBEAT, "Node %d left my region\n",
+ slot->ds_node_num);
+
+ /* last off the live_slot generates a callback */
+ list_del_init(&slot->ds_live_item);
+ if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
+ clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
+
+ o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
+ slot->ds_node_num);
+
+ changed = 1;
+ }
+
+ /* We don't clear this because the node is still
+ * actually writing new blocks. */
+ if (!gen_changed)
+ slot->ds_changed_samples = 0;
+ goto out;
+ }
+ if (slot->ds_changed_samples) {
+ slot->ds_changed_samples = 0;
+ slot->ds_equal_samples = 0;
+ }
+out:
+ spin_unlock(&o2hb_live_lock);
+
+ o2hb_run_event_list(&event);
+
+ o2nm_node_put(node);
+ return changed;
+}
+
+/* This could be faster if we just implmented a find_last_bit, but I
+ * don't think the circumstances warrant it. */
+static int o2hb_highest_node(unsigned long *nodes,
+ int numbits)
+{
+ int highest, node;
+
+ highest = numbits;
+ node = -1;
+ while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) {
+ if (node >= numbits)
+ break;
+
+ highest = node;
+ }
+
+ return highest;
+}
+
+static void o2hb_do_disk_heartbeat(struct o2hb_region *reg)
+{
+ int i, ret, highest_node, change = 0;
+ unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
+ struct bio *write_bio;
+ struct o2hb_bio_wait_ctxt write_wc;
+
+ if (o2nm_configured_node_map(configured_nodes, sizeof(configured_nodes)))
+ return;
+
+ highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
+ if (highest_node >= O2NM_MAX_NODES) {
+ mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n");
+ return;
+ }
+
+ /* No sense in reading the slots of nodes that don't exist
+ * yet. Of course, if the node definitions have holes in them
+ * then we're reading an empty slot anyway... Consider this
+ * best-effort. */
+ ret = o2hb_read_slots(reg, highest_node + 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ return;
+ }
+
+ /* With an up to date view of the slots, we can check that no
+ * other node has been improperly configured to heartbeat in
+ * our slot. */
+ if (!o2hb_check_last_timestamp(reg))
+ mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
+ "in our slot!\n", reg->hr_dev_name);
+
+ /* fill in the proper info for our next heartbeat */
+ o2hb_prepare_block(reg, reg->hr_generation);
+
+ /* And fire off the write. Note that we don't wait on this I/O
+ * until later. */
+ ret = o2hb_issue_node_write(reg, &write_bio, &write_wc);
+ if (ret < 0) {
+ mlog_errno(ret);
+ return;
+ }
+
+ i = -1;
+ while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
+
+ change |= o2hb_check_slot(reg, ®->hr_slots[i]);
+ }
+
+ /*
+ * We have to be sure we've advertised ourselves on disk
+ * before we can go to steady state. This ensures that
+ * people we find in our steady state have seen us.
+ */
+ o2hb_wait_on_io(reg, &write_wc);
+ bio_put(write_bio);
+ o2hb_arm_write_timeout(reg);
+
+ /* let the person who launched us know when things are steady */
+ if (!change && (atomic_read(®->hr_steady_iterations) != 0)) {
+ if (atomic_dec_and_test(®->hr_steady_iterations))
+ wake_up(&o2hb_steady_queue);
+ }
+}
+
+/* Subtract b from a, storing the result in a. a *must* have a larger
+ * value than b. */
+static void o2hb_tv_subtract(struct timeval *a,
+ struct timeval *b)
+{
+ /* just return 0 when a is after b */
+ if (a->tv_sec < b->tv_sec ||
+ (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) {
+ a->tv_sec = 0;
+ a->tv_usec = 0;
+ return;
+ }
+
+ a->tv_sec -= b->tv_sec;
+ a->tv_usec -= b->tv_usec;
+ while ( a->tv_usec < 0 ) {
+ a->tv_sec--;
+ a->tv_usec += 1000000;
+ }
+}
+
+static unsigned int o2hb_elapsed_msecs(struct timeval *start,
+ struct timeval *end)
+{
+ struct timeval res = *end;
+
+ o2hb_tv_subtract(&res, start);
+
+ return res.tv_sec * 1000 + res.tv_usec / 1000;
+}
+
+/*
+ * we ride the region ref that the region dir holds. before the region
+ * dir is removed and drops it ref it will wait to tear down this
+ * thread.
+ */
+static int o2hb_thread(void *data)
+{
+ int i, ret;
+ struct o2hb_region *reg = data;
+ struct bio *write_bio;
+ struct o2hb_bio_wait_ctxt write_wc;
+ struct timeval before_hb, after_hb;
+ unsigned int elapsed_msec;
+
+ mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
+
+ set_user_nice(current, -20);
+
+ while (!kthread_should_stop() && !reg->hr_unclean_stop) {
+ /* We track the time spent inside
+ * o2hb_do_disk_heartbeat so that we avoid more then
+ * hr_timeout_ms between disk writes. On busy systems
+ * this should result in a heartbeat which is less
+ * likely to time itself out. */
+ do_gettimeofday(&before_hb);
+
+ o2hb_do_disk_heartbeat(reg);
+
+ do_gettimeofday(&after_hb);
+ elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb);
+
+ mlog(0, "start = %lu.%lu, end = %lu.%lu, msec = %u\n",
+ before_hb.tv_sec, before_hb.tv_usec,
+ after_hb.tv_sec, after_hb.tv_usec, elapsed_msec);
+
+ if (elapsed_msec < reg->hr_timeout_ms) {
+ /* the kthread api has blocked signals for us so no
+ * need to record the return value. */
+ msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
+ }
+ }
+
+ o2hb_disarm_write_timeout(reg);
+
+ /* unclean stop is only used in very bad situation */
+ for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
+ o2hb_shutdown_slot(®->hr_slots[i]);
+
+ /* Explicit down notification - avoid forcing the other nodes
+ * to timeout on this region when we could just as easily
+ * write a clear generation - thus indicating to them that
+ * this node has left this region.
+ *
+ * XXX: Should we skip this on unclean_stop? */
+ o2hb_prepare_block(reg, 0);
+ ret = o2hb_issue_node_write(reg, &write_bio, &write_wc);
+ if (ret == 0) {
+ o2hb_wait_on_io(reg, &write_wc);
+ bio_put(write_bio);
+ } else {
+ mlog_errno(ret);
+ }
+
+ mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n");
+
+ return 0;
+}
+
+void o2hb_init(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
+ INIT_LIST_HEAD(&o2hb_callbacks[i].list);
+
+ for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
+ INIT_LIST_HEAD(&o2hb_live_slots[i]);
+
+ INIT_LIST_HEAD(&o2hb_node_events);
+
+ memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
+}
+
+/* if we're already in a callback then we're already serialized by the sem */
+static void o2hb_fill_node_map_from_callback(unsigned long *map,
+ unsigned bytes)
+{
+ BUG_ON(
projects / linux-2.6.git / commitdiff