* Library for filesystems writers.
*/
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/pagemap.h>
+#include <linux/slab.h>
#include <linux/mount.h>
#include <linux/vfs.h>
+#include <linux/quotaops.h>
#include <linux/mutex.h>
#include <linux/exportfs.h>
#include <linux/writeback.h>
-#include <linux/buffer_head.h>
+#include <linux/buffer_head.h> /* sync_mapping_buffers */
#include <asm/uaccess.h>
+#include "internal.h"
+
+static inline int simple_positive(struct dentry *dentry)
+{
+ return dentry->d_inode && !d_unhashed(dentry);
+}
+
int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
* Retaining negative dentries for an in-memory filesystem just wastes
* memory and lookup time: arrange for them to be deleted immediately.
*/
-static int simple_delete_dentry(struct dentry *dentry)
+static int simple_delete_dentry(const struct dentry *dentry)
{
return 1;
}
* Lookup the data. This is trivial - if the dentry didn't already
* exist, we know it is negative. Set d_op to delete negative dentries.
*/
-struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
static const struct dentry_operations simple_dentry_operations = {
.d_delete = simple_delete_dentry,
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
- dentry->d_op = &simple_dentry_operations;
+ d_set_d_op(dentry, &simple_dentry_operations);
d_add(dentry, NULL);
return NULL;
}
-int simple_sync_file(struct file * file, struct dentry *dentry, int datasync)
-{
- return 0;
-}
-
int dcache_dir_open(struct inode *inode, struct file *file)
{
- static struct qstr cursor_name = {.len = 1, .name = "."};
+ static struct qstr cursor_name = QSTR_INIT(".", 1);
file->private_data = d_alloc(file->f_path.dentry, &cursor_name);
return 0;
}
-loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
+loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence)
{
- mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
- switch (origin) {
+ struct dentry *dentry = file->f_path.dentry;
+ mutex_lock(&dentry->d_inode->i_mutex);
+ switch (whence) {
case 1:
offset += file->f_pos;
case 0:
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
struct dentry *cursor = file->private_data;
loff_t n = file->f_pos - 2;
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
+ /* d_lock not required for cursor */
list_del(&cursor->d_u.d_child);
- p = file->f_path.dentry->d_subdirs.next;
- while (n && p != &file->f_path.dentry->d_subdirs) {
+ p = dentry->d_subdirs.next;
+ while (n && p != &dentry->d_subdirs) {
struct dentry *next;
next = list_entry(p, struct dentry, d_u.d_child);
- if (!d_unhashed(next) && next->d_inode)
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ if (simple_positive(next))
n--;
+ spin_unlock(&next->d_lock);
p = p->next;
}
list_add_tail(&cursor->d_u.d_child, p);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
}
}
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return offset;
}
i++;
/* fallthrough */
default:
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (filp->f_pos == 2)
list_move(q, &dentry->d_subdirs);
for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
struct dentry *next;
next = list_entry(p, struct dentry, d_u.d_child);
- if (d_unhashed(next) || !next->d_inode)
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ if (!simple_positive(next)) {
+ spin_unlock(&next->d_lock);
continue;
+ }
- spin_unlock(&dcache_lock);
+ spin_unlock(&next->d_lock);
+ spin_unlock(&dentry->d_lock);
if (filldir(dirent, next->d_name.name,
next->d_name.len, filp->f_pos,
next->d_inode->i_ino,
dt_type(next->d_inode)) < 0)
return 0;
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
/* next is still alive */
list_move(q, p);
+ spin_unlock(&next->d_lock);
p = q;
filp->f_pos++;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
}
return 0;
}
.llseek = dcache_dir_lseek,
.read = generic_read_dir,
.readdir = dcache_readdir,
- .fsync = simple_sync_file,
+ .fsync = noop_fsync,
};
const struct inode_operations simple_dir_inode_operations = {
* Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
* will never be mountable)
*/
-int get_sb_pseudo(struct file_system_type *fs_type, char *name,
- const struct super_operations *ops, unsigned long magic,
- struct vfsmount *mnt)
+struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name,
+ const struct super_operations *ops,
+ const struct dentry_operations *dops, unsigned long magic)
{
- struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
+ struct super_block *s;
struct dentry *dentry;
struct inode *root;
- struct qstr d_name = {.name = name, .len = strlen(name)};
+ struct qstr d_name = QSTR_INIT(name, strlen(name));
+ s = sget(fs_type, NULL, set_anon_super, MS_NOUSER, NULL);
if (IS_ERR(s))
- return PTR_ERR(s);
+ return ERR_CAST(s);
- s->s_flags = MS_NOUSER;
s->s_maxbytes = MAX_LFS_FILESIZE;
s->s_blocksize = PAGE_SIZE;
s->s_blocksize_bits = PAGE_SHIFT;
root->i_ino = 1;
root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME;
- dentry = d_alloc(NULL, &d_name);
+ dentry = __d_alloc(s, &d_name);
if (!dentry) {
iput(root);
goto Enomem;
}
- dentry->d_sb = s;
- dentry->d_parent = dentry;
d_instantiate(dentry, root);
s->s_root = dentry;
+ s->s_d_op = dops;
s->s_flags |= MS_ACTIVE;
- simple_set_mnt(mnt, s);
- return 0;
+ return dget(s->s_root);
Enomem:
deactivate_locked_super(s);
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
+}
+
+int simple_open(struct inode *inode, struct file *file)
+{
+ if (inode->i_private)
+ file->private_data = inode->i_private;
+ return 0;
}
int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
inc_nlink(inode);
- atomic_inc(&inode->i_count);
+ ihold(inode);
dget(dentry);
d_instantiate(dentry, inode);
return 0;
}
-static inline int simple_positive(struct dentry *dentry)
-{
- return dentry->d_inode && !d_unhashed(dentry);
-}
-
int simple_empty(struct dentry *dentry)
{
struct dentry *child;
int ret = 0;
- spin_lock(&dcache_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
- if (simple_positive(child))
+ spin_lock(&dentry->d_lock);
+ list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) {
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
+ if (simple_positive(child)) {
+ spin_unlock(&child->d_lock);
goto out;
+ }
+ spin_unlock(&child->d_lock);
+ }
ret = 1;
out:
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
return ret;
}
if (new_dentry->d_inode) {
simple_unlink(new_dir, new_dentry);
- if (they_are_dirs)
+ if (they_are_dirs) {
+ drop_nlink(new_dentry->d_inode);
drop_nlink(old_dir);
+ }
} else if (they_are_dirs) {
drop_nlink(old_dir);
inc_nlink(new_dir);
return 0;
}
+/**
+ * simple_setattr - setattr for simple filesystem
+ * @dentry: dentry
+ * @iattr: iattr structure
+ *
+ * Returns 0 on success, -error on failure.
+ *
+ * simple_setattr is a simple ->setattr implementation without a proper
+ * implementation of size changes.
+ *
+ * It can either be used for in-memory filesystems or special files
+ * on simple regular filesystems. Anything that needs to change on-disk
+ * or wire state on size changes needs its own setattr method.
+ */
+int simple_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+
+ if (iattr->ia_valid & ATTR_SIZE)
+ truncate_setsize(inode, iattr->ia_size);
+ setattr_copy(inode, iattr);
+ mark_inode_dirty(inode);
+ return 0;
+}
+EXPORT_SYMBOL(simple_setattr);
+
int simple_readpage(struct file *file, struct page *page)
{
clear_highpage(page);
return 0;
}
-int simple_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- if (!PageUptodate(page)) {
- if (to - from != PAGE_CACHE_SIZE)
- zero_user_segments(page,
- 0, from,
- to, PAGE_CACHE_SIZE);
- }
- return 0;
-}
-
int simple_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
struct page *page;
pgoff_t index;
- unsigned from;
index = pos >> PAGE_CACHE_SHIFT;
- from = pos & (PAGE_CACHE_SIZE - 1);
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
*pagep = page;
- return simple_prepare_write(file, page, from, from+len);
-}
+ if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
-static int simple_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- struct inode *inode = page->mapping->host;
- loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
-
- if (!PageUptodate(page))
- SetPageUptodate(page);
- /*
- * No need to use i_size_read() here, the i_size
- * cannot change under us because we hold the i_mutex.
- */
- if (pos > inode->i_size)
- i_size_write(inode, pos);
- set_page_dirty(page);
+ zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE);
+ }
return 0;
}
+/**
+ * simple_write_end - .write_end helper for non-block-device FSes
+ * @available: See .write_end of address_space_operations
+ * @file: "
+ * @mapping: "
+ * @pos: "
+ * @len: "
+ * @copied: "
+ * @page: "
+ * @fsdata: "
+ *
+ * simple_write_end does the minimum needed for updating a page after writing is
+ * done. It has the same API signature as the .write_end of
+ * address_space_operations vector. So it can just be set onto .write_end for
+ * FSes that don't need any other processing. i_mutex is assumed to be held.
+ * Block based filesystems should use generic_write_end().
+ * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
+ * is not called, so a filesystem that actually does store data in .write_inode
+ * should extend on what's done here with a call to mark_inode_dirty() in the
+ * case that i_size has changed.
+ */
int simple_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
- unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+ struct inode *inode = page->mapping->host;
+ loff_t last_pos = pos + copied;
/* zero the stale part of the page if we did a short copy */
if (copied < len) {
- void *kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + from + copied, 0, len - copied);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+
+ zero_user(page, from + copied, len - copied);
}
- simple_commit_write(file, page, from, from+copied);
+ if (!PageUptodate(page))
+ SetPageUptodate(page);
+ /*
+ * No need to use i_size_read() here, the i_size
+ * cannot change under us because we hold the i_mutex.
+ */
+ if (last_pos > inode->i_size)
+ i_size_write(inode, last_pos);
+ set_page_dirty(page);
unlock_page(page);
page_cache_release(page);
* unique inode values later for this filesystem, then you must take care
* to pass it an appropriate max_reserved value to avoid collisions.
*/
-int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
+int simple_fill_super(struct super_block *s, unsigned long magic,
+ struct tree_descr *files)
{
struct inode *inode;
struct dentry *root;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
- inode->i_nlink = 2;
- root = d_alloc_root(inode);
- if (!root) {
- iput(inode);
+ set_nlink(inode, 2);
+ root = d_make_root(inode);
+ if (!root)
return -ENOMEM;
- }
for (i = 0; !files->name || files->name[0]; i++, files++) {
if (!files->name)
continue;
if (!dentry)
goto out;
inode = new_inode(s);
- if (!inode)
+ if (!inode) {
+ dput(dentry);
goto out;
+ }
inode->i_mode = S_IFREG | files->mode;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_fop = files->ops;
return 0;
out:
d_genocide(root);
+ shrink_dcache_parent(root);
dput(root);
return -ENOMEM;
}
spin_lock(&pin_fs_lock);
if (unlikely(!*mount)) {
spin_unlock(&pin_fs_lock);
- mnt = vfs_kern_mount(type, 0, type->name, NULL);
+ mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, NULL);
if (IS_ERR(mnt))
return PTR_ERR(mnt);
spin_lock(&pin_fs_lock);
return count;
}
+/**
+ * simple_write_to_buffer - copy data from user space to the buffer
+ * @to: the buffer to write to
+ * @available: the size of the buffer
+ * @ppos: the current position in the buffer
+ * @from: the user space buffer to read from
+ * @count: the maximum number of bytes to read
+ *
+ * The simple_write_to_buffer() function reads up to @count bytes from the user
+ * space address starting at @from into the buffer @to at offset @ppos.
+ *
+ * On success, the number of bytes written is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
+ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+ const void __user *from, size_t count)
+{
+ loff_t pos = *ppos;
+ size_t res;
+
+ if (pos < 0)
+ return -EINVAL;
+ if (pos >= available || !count)
+ return 0;
+ if (count > available - pos)
+ count = available - pos;
+ res = copy_from_user(to + pos, from, count);
+ if (res == count)
+ return -EFAULT;
+ count -= res;
+ *ppos = pos + count;
+ return count;
+}
+
/**
* memory_read_from_buffer - copy data from the buffer
* @to: the kernel space buffer to read to
if (copy_from_user(attr->set_buf, buf, size))
goto out;
- ret = len; /* claim we got the whole input */
attr->set_buf[size] = '\0';
- val = simple_strtol(attr->set_buf, NULL, 0);
- attr->set(attr->data, val);
+ val = simple_strtoll(attr->set_buf, NULL, 0);
+ ret = attr->set(attr->data, val);
+ if (ret == 0)
+ ret = len; /* on success, claim we got the whole input */
out:
mutex_unlock(&attr->mutex);
return ret;
EXPORT_SYMBOL_GPL(generic_fh_to_dentry);
/**
- * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
+ * generic_fh_to_parent - generic helper for the fh_to_parent export operation
* @sb: filesystem to do the file handle conversion on
* @fid: file handle to convert
* @fh_len: length of the file handle in bytes
}
EXPORT_SYMBOL_GPL(generic_fh_to_parent);
-int simple_fsync(struct file *file, struct dentry *dentry, int datasync)
+/**
+ * generic_file_fsync - generic fsync implementation for simple filesystems
+ * @file: file to synchronize
+ * @datasync: only synchronize essential metadata if true
+ *
+ * This is a generic implementation of the fsync method for simple
+ * filesystems which track all non-inode metadata in the buffers list
+ * hanging off the address_space structure.
+ */
+int generic_file_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
{
- struct writeback_control wbc = {
- .sync_mode = WB_SYNC_ALL,
- .nr_to_write = 0, /* metadata-only; caller takes care of data */
- };
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = file->f_mapping->host;
int err;
int ret;
+ err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (err)
+ return err;
+
+ mutex_lock(&inode->i_mutex);
ret = sync_mapping_buffers(inode->i_mapping);
if (!(inode->i_state & I_DIRTY))
- return ret;
+ goto out;
if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
- return ret;
+ goto out;
- err = sync_inode(inode, &wbc);
+ err = sync_inode_metadata(inode, 1);
if (ret == 0)
ret = err;
+out:
+ mutex_unlock(&inode->i_mutex);
return ret;
}
-EXPORT_SYMBOL(simple_fsync);
+EXPORT_SYMBOL(generic_file_fsync);
+
+/**
+ * generic_check_addressable - Check addressability of file system
+ * @blocksize_bits: log of file system block size
+ * @num_blocks: number of blocks in file system
+ *
+ * Determine whether a file system with @num_blocks blocks (and a
+ * block size of 2**@blocksize_bits) is addressable by the sector_t
+ * and page cache of the system. Return 0 if so and -EFBIG otherwise.
+ */
+int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks)
+{
+ u64 last_fs_block = num_blocks - 1;
+ u64 last_fs_page =
+ last_fs_block >> (PAGE_CACHE_SHIFT - blocksize_bits);
+
+ if (unlikely(num_blocks == 0))
+ return 0;
+
+ if ((blocksize_bits < 9) || (blocksize_bits > PAGE_CACHE_SHIFT))
+ return -EINVAL;
+
+ if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) ||
+ (last_fs_page > (pgoff_t)(~0ULL))) {
+ return -EFBIG;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(generic_check_addressable);
+
+/*
+ * No-op implementation of ->fsync for in-memory filesystems.
+ */
+int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ return 0;
+}
EXPORT_SYMBOL(dcache_dir_close);
EXPORT_SYMBOL(dcache_dir_lseek);
EXPORT_SYMBOL(dcache_dir_open);
EXPORT_SYMBOL(dcache_readdir);
EXPORT_SYMBOL(generic_read_dir);
-EXPORT_SYMBOL(get_sb_pseudo);
+EXPORT_SYMBOL(mount_pseudo);
EXPORT_SYMBOL(simple_write_begin);
EXPORT_SYMBOL(simple_write_end);
EXPORT_SYMBOL(simple_dir_inode_operations);
EXPORT_SYMBOL(simple_dir_operations);
EXPORT_SYMBOL(simple_empty);
-EXPORT_SYMBOL(d_alloc_name);
EXPORT_SYMBOL(simple_fill_super);
EXPORT_SYMBOL(simple_getattr);
+EXPORT_SYMBOL(simple_open);
EXPORT_SYMBOL(simple_link);
EXPORT_SYMBOL(simple_lookup);
EXPORT_SYMBOL(simple_pin_fs);
-EXPORT_UNUSED_SYMBOL(simple_prepare_write);
EXPORT_SYMBOL(simple_readpage);
EXPORT_SYMBOL(simple_release_fs);
EXPORT_SYMBOL(simple_rename);
EXPORT_SYMBOL(simple_rmdir);
EXPORT_SYMBOL(simple_statfs);
-EXPORT_SYMBOL(simple_sync_file);
+EXPORT_SYMBOL(noop_fsync);
EXPORT_SYMBOL(simple_unlink);
EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(simple_write_to_buffer);
EXPORT_SYMBOL(memory_read_from_buffer);
EXPORT_SYMBOL(simple_transaction_set);
EXPORT_SYMBOL(simple_transaction_get);
Code Review / linux-3.10.git / blobdiff