xattr support for btrfs
Josef Bacik [Fri, 16 Nov 2007 16:45:54 +0000 (11:45 -0500)]
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile
fs/btrfs/acl.c [new file with mode: 0644]
fs/btrfs/ctree.h
fs/btrfs/dir-item.c
fs/btrfs/inode.c
fs/btrfs/print-tree.c
fs/btrfs/super.c
fs/btrfs/xattr.c [new file with mode: 0644]
fs/btrfs/xattr.h [new file with mode: 0644]

index 551743b..d5804c5 100644 (file)
@@ -5,7 +5,7 @@ obj-m  := btrfs.o
 btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
           hash.o file-item.o inode-item.o inode-map.o disk-io.o \
           transaction.o bit-radix.o inode.o file.o tree-defrag.o \
-          extent_map.o sysfs.o struct-funcs.o
+          extent_map.o sysfs.o struct-funcs.o xattr.o acl.o
 
 #btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 #        root-tree.o dir-item.o hash.o file-item.o inode-item.o \
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
new file mode 100644 (file)
index 0000000..aee9f06
--- /dev/null
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2007 Red Hat.  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 v2 as published by the Free Software Foundation.
+ *
+ * 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/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include "ctree.h"
+#include "xattr.h"
+
+static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
+                                     void *value, size_t size)
+{
+       return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
+                              value, size);
+}
+
+static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
+                                     const void *value, size_t size, int flags)
+{
+       return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
+                              value, size, flags);
+}
+
+static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
+                                      void *value, size_t size)
+{
+       return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+                              name, value, size);
+}
+
+static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
+                                      const void *value, size_t size, int flags)
+{
+       return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+                              name, value, size, flags);
+}
+
+struct xattr_handler btrfs_xattr_acl_default_handler = {
+       .prefix = POSIX_ACL_XATTR_DEFAULT,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_acl_default_get,
+       .set    = btrfs_xattr_acl_default_set,
+};
+
+struct xattr_handler btrfs_xattr_acl_access_handler = {
+       .prefix = POSIX_ACL_XATTR_ACCESS,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_acl_access_get,
+       .set    = btrfs_xattr_acl_access_set,
+};
index 030d21d..27cadae 100644 (file)
@@ -63,7 +63,8 @@ extern struct kmem_cache *btrfs_path_cachep;
 #define BTRFS_FT_FIFO          5
 #define BTRFS_FT_SOCK          6
 #define BTRFS_FT_SYMLINK       7
-#define BTRFS_FT_MAX           8
+#define BTRFS_FT_XATTR         8
+#define BTRFS_FT_MAX           9
 
 /*
  * the key defines the order in the tree, and so it also defines (optimal)
@@ -226,7 +227,7 @@ struct btrfs_inode_item {
 
 struct btrfs_dir_item {
        struct btrfs_disk_key location;
-       __le16 flags;
+       __le16 data_len;
        __le16 name_len;
        u8 type;
 } __attribute__ ((__packed__));
@@ -367,7 +368,7 @@ struct btrfs_root {
  * the FS
  */
 #define BTRFS_INODE_ITEM_KEY           1
-
+#define BTRFS_XATTR_ITEM_KEY           2
 /* reserve 2-15 close to the inode for later flexibility */
 
 /*
@@ -621,7 +622,7 @@ static inline void btrfs_set_item_key(struct extent_buffer *eb,
 }
 
 /* struct btrfs_dir_item */
-BTRFS_SETGET_FUNCS(dir_flags, struct btrfs_dir_item, flags, 16);
+BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
 BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
 
@@ -962,6 +963,15 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct btrfs_path *path,
                              struct btrfs_dir_item *di);
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root, const char *name,
+                           u16 name_len, const void *data, u16 data_len,
+                           u64 dir);
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+                                         struct btrfs_root *root,
+                                         struct btrfs_path *path, u64 dir,
+                                         const char *name, u16 name_len,
+                                         int mod);
 /* inode-map.c */
 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
                             struct btrfs_root *fs_root,
@@ -1039,4 +1049,8 @@ int btrfs_sysfs_add_root(struct btrfs_root *root);
 void btrfs_sysfs_del_root(struct btrfs_root *root);
 void btrfs_sysfs_del_super(struct btrfs_fs_info *root);
 
+/* xattr.c */
+ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
+int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct inode *inode);
 #endif
index 514a1dc..ddbe12a 100644 (file)
@@ -43,8 +43,6 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
                        return ERR_PTR(-EEXIST);
                ret = btrfs_extend_item(trans, root, path, data_size);
                WARN_ON(ret > 0);
-               if (ret)
-                       return ERR_PTR(ret);
        }
        if (ret < 0)
                return ERR_PTR(ret);
@@ -57,6 +55,57 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
        return (struct btrfs_dir_item *)ptr;
 }
 
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root, const char *name,
+                           u16 name_len, const void *data, u16 data_len,
+                           u64 dir)
+{
+       int ret = 0;
+       struct btrfs_path *path;
+       struct btrfs_dir_item *dir_item;
+       unsigned long name_ptr, data_ptr;
+       struct btrfs_key key, location;
+       struct btrfs_disk_key disk_key;
+       struct extent_buffer *leaf;
+       u32 data_size;
+
+       key.objectid = dir;
+       btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+       ret = btrfs_name_hash(name, name_len, &key.offset);
+       BUG_ON(ret);
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       data_size = sizeof(*dir_item) + name_len + data_len;
+       dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+                                       name, name_len);
+       /*
+        * FIXME: at some point we should handle xattr's that are larger than
+        * what we can fit in our leaf.  We set location to NULL b/c we arent
+        * pointing at anything else, that will change if we store the xattr
+        * data in a separate inode.
+        */
+       BUG_ON(IS_ERR(dir_item));
+       memset(&location, 0, sizeof(location));
+
+       leaf = path->nodes[0];
+       btrfs_cpu_key_to_disk(&disk_key, &location);
+       btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+       btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
+       btrfs_set_dir_name_len(leaf, dir_item, name_len);
+       btrfs_set_dir_data_len(leaf, dir_item, data_len);
+       name_ptr = (unsigned long)(dir_item + 1);
+       data_ptr = (unsigned long)((char *)name_ptr + name_len);
+
+       write_extent_buffer(leaf, name, name_ptr, name_len);
+       write_extent_buffer(leaf, data, data_ptr, data_len);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+
+       btrfs_free_path(path);
+       return ret;
+}
+
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
                          *root, const char *name, int name_len, u64 dir,
                          struct btrfs_key *location, u8 type)
@@ -90,7 +139,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
        btrfs_cpu_key_to_disk(&disk_key, location);
        btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
        btrfs_set_dir_type(leaf, dir_item, type);
-       btrfs_set_dir_flags(leaf, dir_item, 0);
+       btrfs_set_dir_data_len(leaf, dir_item, 0);
        btrfs_set_dir_name_len(leaf, dir_item, name_len);
        name_ptr = (unsigned long)(dir_item + 1);
 
@@ -117,7 +166,7 @@ second_insert:
        btrfs_cpu_key_to_disk(&disk_key, location);
        btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
        btrfs_set_dir_type(leaf, dir_item, type);
-       btrfs_set_dir_flags(leaf, dir_item, 0);
+       btrfs_set_dir_data_len(leaf, dir_item, 0);
        btrfs_set_dir_name_len(leaf, dir_item, name_len);
        name_ptr = (unsigned long)(dir_item + 1);
        write_extent_buffer(leaf, name, name_ptr, name_len);
@@ -194,6 +243,43 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
        return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+                                         struct btrfs_root *root,
+                                         struct btrfs_path *path, u64 dir,
+                                         const char *name, u16 name_len,
+                                         int mod)
+{
+       int ret;
+       struct btrfs_key key;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+       struct btrfs_key found_key;
+       struct extent_buffer *leaf;
+
+       key.objectid = dir;
+       btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+       ret = btrfs_name_hash(name, name_len, &key.offset);
+       BUG_ON(ret);
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0) {
+               if (path->slots[0] == 0)
+                       return NULL;
+               path->slots[0]--;
+       }
+
+       leaf = path->nodes[0];
+       btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+       if (found_key.objectid != dir ||
+           btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
+           found_key.offset != key.offset)
+               return NULL;
+
+       return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
                              struct btrfs_path *path,
                              const char *name, int name_len)
@@ -210,7 +296,8 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
        total_len = btrfs_item_size_nr(leaf, path->slots[0]);
        while(cur < total_len) {
                this_len = sizeof(*dir_item) +
-                       btrfs_dir_name_len(leaf, dir_item);
+                       btrfs_dir_name_len(leaf, dir_item) +
+                       btrfs_dir_data_len(leaf, dir_item);
                name_ptr = (unsigned long)(dir_item + 1);
 
                if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
@@ -236,7 +323,8 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
        int ret = 0;
 
        leaf = path->nodes[0];
-       sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di);
+       sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
+               btrfs_dir_data_len(leaf, di);
        item_len = btrfs_item_size_nr(leaf, path->slots[0]);
        if (sub_item_len == item_len) {
                ret = btrfs_del_item(trans, root, path);
index d6d3246..37f8e03 100644 (file)
@@ -32,6 +32,7 @@
 #include <linux/compat.h>
 #include <linux/bit_spinlock.h>
 #include <linux/version.h>
+#include <linux/xattr.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -841,6 +842,9 @@ void btrfs_delete_inode(struct inode *inode)
        ret = btrfs_truncate_in_trans(trans, root, inode);
        if (ret)
                goto no_delete_lock;
+       ret = btrfs_delete_xattrs(trans, root, inode);
+       if (ret)
+               goto no_delete_lock;
        ret = btrfs_free_inode(trans, root, inode);
        if (ret)
                goto no_delete_lock;
@@ -1110,7 +1114,8 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
                        if (over)
                                goto nopos;
-                       di_len = btrfs_dir_name_len(leaf, di) + sizeof(*di);
+                       di_len = btrfs_dir_name_len(leaf, di) +
+                               btrfs_dir_data_len(leaf, di) +sizeof(*di);
                        di_cur += di_len;
                        di = (struct btrfs_dir_item *)((char *)di + di_len);
                }
@@ -2519,6 +2524,10 @@ static struct inode_operations btrfs_dir_inode_operations = {
        .symlink        = btrfs_symlink,
        .setattr        = btrfs_setattr,
        .mknod          = btrfs_mknod,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
+       .listxattr      = btrfs_listxattr,
+       .removexattr    = generic_removexattr,
 };
 
 static struct inode_operations btrfs_dir_ro_inode_operations = {
@@ -2567,6 +2576,10 @@ static struct inode_operations btrfs_file_inode_operations = {
        .truncate       = btrfs_truncate,
        .getattr        = btrfs_getattr,
        .setattr        = btrfs_setattr,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
+       .listxattr      = btrfs_listxattr,
+       .removexattr    = generic_removexattr,
 };
 
 static struct inode_operations btrfs_special_inode_operations = {
index 9f8696c..030324f 100644 (file)
@@ -58,9 +58,8 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
                case BTRFS_DIR_ITEM_KEY:
                        di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
                        btrfs_dir_item_key_to_cpu(l, di, &found_key);
-                       printk("\t\tdir oid %llu flags %u type %u\n",
+                       printk("\t\tdir oid %llu type %u\n",
                                (unsigned long long)found_key.objectid,
-                               btrfs_dir_flags(l, di),
                                btrfs_dir_type(l, di));
                        break;
                case BTRFS_ROOT_ITEM_KEY:
index f94aa1f..c46bc39 100644 (file)
@@ -40,6 +40,7 @@
 #include "btrfs_inode.h"
 #include "ioctl.h"
 #include "print-tree.h"
+#include "xattr.h"
 
 #define BTRFS_SUPER_MAGIC 0x9123683E
 
@@ -106,6 +107,7 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
        sb->s_maxbytes = MAX_LFS_FILESIZE;
        sb->s_magic = BTRFS_SUPER_MAGIC;
        sb->s_op = &btrfs_super_ops;
+       sb->s_xattr = btrfs_xattr_handlers;
        sb->s_time_gran = 1;
 
        tree_root = open_ctree(sb);
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
new file mode 100644 (file)
index 0000000..f4ac5e0
--- /dev/null
@@ -0,0 +1,497 @@
+/*
+ * Copyright (C) 2007 Red Hat.  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 v2 as published by the Free Software Foundation.
+ *
+ * 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/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/rwsem.h>
+#include <linux/xattr.h>
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "transaction.h"
+#include "xattr.h"
+#include "disk-io.h"
+
+static struct xattr_handler *btrfs_xattr_handler_map[] = {
+       [BTRFS_XATTR_INDEX_USER]                = &btrfs_xattr_user_handler,
+       [BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS]    = &btrfs_xattr_acl_access_handler,
+       [BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT]   = &btrfs_xattr_acl_default_handler,
+       [BTRFS_XATTR_INDEX_TRUSTED]             = &btrfs_xattr_trusted_handler,
+       [BTRFS_XATTR_INDEX_SECURITY]            = &btrfs_xattr_security_handler,
+       [BTRFS_XATTR_INDEX_SYSTEM]              = &btrfs_xattr_system_handler,
+};
+
+struct xattr_handler *btrfs_xattr_handlers[] = {
+       &btrfs_xattr_user_handler,
+       &btrfs_xattr_acl_access_handler,
+       &btrfs_xattr_acl_default_handler,
+       &btrfs_xattr_trusted_handler,
+       &btrfs_xattr_security_handler,
+       &btrfs_xattr_system_handler,
+       NULL,
+};
+
+/*
+ * @param name - the xattr name
+ * @return - the xattr_handler for the xattr, NULL if its not found
+ *
+ * use this with listxattr where we don't already know the type of xattr we
+ * have
+ */
+static struct xattr_handler *find_btrfs_xattr_handler(struct extent_buffer *l,
+                                                     unsigned long name_ptr,
+                                                     u16 name_len)
+{
+       struct xattr_handler *handler = NULL;
+       int i = 0;
+
+       for (handler = btrfs_xattr_handlers[i]; handler != NULL; i++,
+            handler = btrfs_xattr_handlers[i]) {
+               u16 prefix_len = strlen(handler->prefix);
+
+               if (name_len < prefix_len)
+                       continue;
+
+               if (memcmp_extent_buffer(l, handler->prefix, name_ptr,
+                                        prefix_len) == 0)
+                       break;
+       }
+
+       return handler;
+}
+
+/*
+ * @param name_index - the index for the xattr handler
+ * @return the xattr_handler if we found it, NULL otherwise
+ *
+ * use this if we know the type of the xattr already
+ */
+static struct xattr_handler *btrfs_xattr_handler(int name_index)
+{
+       struct xattr_handler *handler = NULL;
+
+       if (name_index >= 0 &&
+           name_index < ARRAY_SIZE(btrfs_xattr_handler_map))
+               handler = btrfs_xattr_handler_map[name_index];
+
+       return handler;
+}
+
+static inline char *get_name(const char *name, int name_index)
+{
+       char *ret = NULL;
+       struct xattr_handler *handler = btrfs_xattr_handler(name_index);
+       int prefix_len;
+
+       if (!handler)
+               return ret;
+
+       prefix_len = strlen(handler->prefix);
+
+       ret = kmalloc(strlen(name) + prefix_len + 1, GFP_KERNEL);
+       if (!ret)
+               return ret;
+
+       memcpy(ret, handler->prefix, prefix_len);
+       memcpy(ret+prefix_len, name, strlen(name));
+       ret[prefix_len + strlen(name)] = '\0';
+
+       return ret;
+}
+
+size_t btrfs_xattr_generic_list(struct inode *inode, char *list,
+                               size_t list_size, const char *name,
+                               size_t name_len)
+{
+       if (list && (name_len+1) <= list_size) {
+               memcpy(list, name, name_len);
+               list[name_len] = '\0';
+       } else
+               return -ERANGE;
+
+       return name_len+1;
+}
+
+ssize_t btrfs_xattr_get(struct inode *inode, int name_index,
+                       const char *attr_name, void *buffer, size_t size)
+{
+       struct btrfs_dir_item *di;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_path *path;
+       struct extent_buffer *leaf;
+       struct xattr_handler *handler = btrfs_xattr_handler(name_index);
+       int ret = 0;
+       unsigned long data_ptr;
+       char *name;
+
+       if (!handler)
+               return -EOPNOTSUPP;
+
+       /* just in case... */
+       if (*attr_name == '\0')
+               return -EINVAL;
+
+       name = get_name(attr_name, name_index);
+       if (!name)
+               return -ENOMEM;
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               kfree(name);
+               return -ENOMEM;
+       }
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       /* lookup the xattr by name */
+       di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
+                               strlen(name), 0);
+       if (!di || IS_ERR(di)) {
+               ret = -ENODATA;
+               goto out;
+       }
+
+       leaf = path->nodes[0];
+       /* if size is 0, that means we want the size of the attr */
+       if (!size) {
+               ret = btrfs_dir_data_len(leaf, di);
+               goto out;
+       }
+
+       /* now get the data out of our dir_item */
+       if (btrfs_dir_data_len(leaf, di) > size) {
+               ret = -ERANGE;
+               goto out;
+       }
+       data_ptr = (unsigned long)((char *)(di + 1) +
+                                  btrfs_dir_name_len(leaf, di));
+       read_extent_buffer(leaf, buffer, data_ptr,
+                          btrfs_dir_name_len(leaf, di));
+       ret = btrfs_dir_data_len(leaf, di);
+
+out:
+       mutex_unlock(&root->fs_info->fs_mutex);
+       kfree(name);
+       btrfs_free_path(path);
+       return ret;
+}
+
+int btrfs_xattr_set(struct inode *inode, int name_index,
+                   const char *attr_name, const void *value, size_t size,
+                   int flags)
+{
+       struct btrfs_dir_item *di;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_path *path;
+       struct xattr_handler *handler = btrfs_xattr_handler(name_index);
+       char *name;
+       int ret = 0, mod = 0;
+
+       if (!handler)
+               return -EOPNOTSUPP;
+
+       /* just in case... */
+       if (*attr_name == '\0')
+               return -EINVAL;
+
+       name = get_name(attr_name, name_index);
+       if (!name)
+               return -ENOMEM;
+
+       path = btrfs_alloc_path();
+       if (!path) {
+               kfree(name);
+               return -ENOMEM;
+       }
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, inode);
+
+       /* first lets see if we already have this xattr */
+       di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
+                               strlen(name), -1);
+       if (IS_ERR(di)) {
+               ret = PTR_ERR(di);
+               goto out;
+       }
+
+       /* ok we already have this xattr, lets remove it */
+       if (di) {
+               /* if we want create only exit */
+               if (flags & XATTR_CREATE) {
+                       ret = -EEXIST;
+                       goto out;
+               }
+
+               ret = btrfs_delete_one_dir_name(trans, root, path, di);
+               if (ret)
+                       goto out;
+               btrfs_release_path(root, path);
+
+               /* if we don't have a value then we are removing the xattr */
+               if (!value) {
+                       mod = 1;
+                       goto out;
+               }
+       } else if (flags & XATTR_REPLACE) {
+               /* we couldn't find the attr to replace, so error out */
+               ret = -ENODATA;
+               goto out;
+       }
+
+       /* ok we have to create a completely new xattr */
+       ret = btrfs_insert_xattr_item(trans, root, name, strlen(name),
+                                     value, size, inode->i_ino);
+       if (ret)
+               goto out;
+       mod = 1;
+
+out:
+       if (mod) {
+               inode->i_ctime = CURRENT_TIME;
+               ret = btrfs_update_inode(trans, root, inode);
+       }
+
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       kfree(name);
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+       struct btrfs_key key, found_key;
+       struct inode *inode = dentry->d_inode;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_path *path;
+       struct btrfs_item *item;
+       struct extent_buffer *leaf;
+       struct btrfs_dir_item *di;
+       struct xattr_handler *handler;
+       int ret = 0, slot, advance;
+       size_t total_size = 0, size_left = size, written;
+       unsigned long name_ptr;
+       char *name;
+       u32 nritems;
+
+       /*
+        * ok we want all objects associated with this id.
+        * NOTE: we set key.offset = 0; because we want to start with the
+        * first xattr that we find and walk forward
+        */
+       key.objectid = inode->i_ino;
+       btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+       key.offset = 0;
+
+       path = btrfs_alloc_path();
+       path->reada = 2;
+       if (!path)
+               return -ENOMEM;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+
+       /* search for our xattrs */
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               goto err;
+       ret = 0;
+       advance = 0;
+       while (1) {
+               leaf = path->nodes[0];
+               nritems = btrfs_header_nritems(leaf);
+               slot = path->slots[0];
+
+               /* this is where we start walking through the path */
+               if (advance || slot >= nritems) {
+                       /*
+                        * if we've reached the last slot in this leaf we need
+                        * to go to the next leaf and reset everything
+                        */
+                       if (slot >= nritems-1) {
+                               ret = btrfs_next_leaf(root, path);
+                               if (ret)
+                                       break;
+                               leaf = path->nodes[0];
+                               nritems = btrfs_header_nritems(leaf);
+                               slot = path->slots[0];
+                       } else {
+                               /*
+                                * just walking through the slots on this leaf
+                                */
+                               slot++;
+                               path->slots[0]++;
+                       }
+               }
+               advance = 1;
+
+               item = btrfs_item_nr(leaf, slot);
+               btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+               /* check to make sure this item is what we want */
+               if (found_key.objectid != key.objectid)
+                       break;
+               if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
+                       break;
+
+               di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+
+               total_size += btrfs_dir_name_len(leaf, di)+1;
+
+               /* we are just looking for how big our buffer needs to be */
+               if (!size)
+                       continue;
+
+               /* find our handler for this xattr */
+               name_ptr = (unsigned long)(di + 1);
+               handler = find_btrfs_xattr_handler(leaf, name_ptr,
+                                                  btrfs_dir_name_len(leaf, di));
+               if (!handler) {
+                       printk(KERN_ERR "btrfs: unsupported xattr found\n");
+                       continue;
+               }
+
+               name = kmalloc(btrfs_dir_name_len(leaf, di), GFP_KERNEL);
+               read_extent_buffer(leaf, name, name_ptr,
+                                  btrfs_dir_name_len(leaf, di));
+
+               /* call the list function associated with this xattr */
+               written = handler->list(inode, buffer, size_left, name,
+                                       btrfs_dir_name_len(leaf, di));
+               kfree(name);
+
+               if (written < 0) {
+                       ret = -ERANGE;
+                       break;
+               }
+
+               size_left -= written;
+               buffer += written;
+       }
+       ret = total_size;
+
+err:
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+/*
+ * delete all the xattrs associated with the inode.  fs_mutex should be
+ * held when we come into here
+ */
+int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct inode *inode)
+{
+       struct btrfs_path *path;
+       struct btrfs_key key, found_key;
+       struct btrfs_item *item;
+       struct extent_buffer *leaf;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = inode->i_ino;
+       btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+       key.offset = (u64)-1;
+
+       while(1) {
+               /* look for our next xattr */
+               ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+               if (ret < 0)
+                       goto out;
+               BUG_ON(ret == 0);
+
+               if (path->slots[0] == 0)
+                       break;
+
+               path->slots[0]--;
+               leaf = path->nodes[0];
+               item = btrfs_item_nr(leaf, path->slots[0]);
+               btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+               if (found_key.objectid != key.objectid)
+                       break;
+               if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
+                       break;
+
+               ret = btrfs_del_item(trans, root, path);
+               BUG_ON(ret);
+               btrfs_release_path(root, path);
+       }
+       ret = 0;
+out:
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+/*
+ * Handler functions
+ */
+#define BTRFS_XATTR_SETGET_FUNCS(name, index)                          \
+static int btrfs_xattr_##name##_get(struct inode *inode,               \
+                                   const char *name, void *value,      \
+                                   size_t size)                        \
+{                                                                      \
+       return btrfs_xattr_get(inode, index, name, value, size);        \
+}                                                                      \
+static int btrfs_xattr_##name##_set(struct inode *inode,               \
+                                   const char *name, const void *value,\
+                                   size_t size, int flags)             \
+{                                                                      \
+       return btrfs_xattr_set(inode, index, name, value, size, flags); \
+}                                                                      \
+
+BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY);
+BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM);
+BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER);
+BTRFS_XATTR_SETGET_FUNCS(trusted, BTRFS_XATTR_INDEX_TRUSTED);
+
+struct xattr_handler btrfs_xattr_security_handler = {
+       .prefix = XATTR_SECURITY_PREFIX,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_security_get,
+       .set    = btrfs_xattr_security_set,
+};
+
+struct xattr_handler btrfs_xattr_system_handler = {
+       .prefix = XATTR_SYSTEM_PREFIX,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_system_get,
+       .set    = btrfs_xattr_system_set,
+};
+
+struct xattr_handler btrfs_xattr_user_handler = {
+       .prefix = XATTR_USER_PREFIX,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_user_get,
+       .set    = btrfs_xattr_user_set,
+};
+
+struct xattr_handler btrfs_xattr_trusted_handler = {
+       .prefix = XATTR_USER_PREFIX,
+       .list   = btrfs_xattr_generic_list,
+       .get    = btrfs_xattr_trusted_get,
+       .set    = btrfs_xattr_trusted_set,
+};
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
new file mode 100644 (file)
index 0000000..b2e47e3
--- /dev/null
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2007 Red Hat.  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 v2 as published by the Free Software Foundation.
+ *
+ * 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 __XATTR__
+#define __XATTR__
+
+#include <linux/xattr.h>
+#include "ctree.h"
+
+/* Name indexes */
+enum {
+       BTRFS_XATTR_INDEX_USER,
+       BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+       BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+       BTRFS_XATTR_INDEX_TRUSTED,
+       BTRFS_XATTR_INDEX_SECURITY,
+       BTRFS_XATTR_INDEX_SYSTEM,
+       BTRFS_XATTR_INDEX_END,
+};
+
+extern struct xattr_handler btrfs_xattr_user_handler;
+extern struct xattr_handler btrfs_xattr_trusted_handler;
+extern struct xattr_handler btrfs_xattr_acl_access_handler;
+extern struct xattr_handler btrfs_xattr_acl_default_handler;
+extern struct xattr_handler btrfs_xattr_security_handler;
+extern struct xattr_handler btrfs_xattr_system_handler;
+
+extern struct xattr_handler *btrfs_xattr_handlers[];
+
+ssize_t btrfs_xattr_get(struct inode *inode, int name_index, const char *name,
+                       void *buffer, size_t size);
+int btrfs_xattr_set(struct inode *inode, int name_index, const char *name,
+                       const void *value, size_t size, int flags);
+
+/*
+ * the only reason this is public is for acl.c.  There may be a point where
+ * acl.c doesn't need it, and if thats the case we need to remove it and make
+ * it static in xattr.c
+ */
+size_t btrfs_xattr_generic_list(struct inode *inode, char *list,
+                               size_t list_size, const char *name,
+                               size_t name_len);
+#endif /* __XATTR__ */