3 * Library for filesystems writers.
6 #include <linux/module.h>
7 #include <linux/pagemap.h>
8 #include <linux/slab.h>
9 #include <linux/mount.h>
10 #include <linux/vfs.h>
11 #include <linux/quotaops.h>
12 #include <linux/mutex.h>
13 #include <linux/exportfs.h>
14 #include <linux/writeback.h>
15 #include <linux/buffer_head.h>
17 #include <asm/uaccess.h>
19 int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
22 struct inode *inode = dentry->d_inode;
23 generic_fillattr(inode, stat);
24 stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9);
28 int simple_statfs(struct dentry *dentry, struct kstatfs *buf)
30 buf->f_type = dentry->d_sb->s_magic;
31 buf->f_bsize = PAGE_CACHE_SIZE;
32 buf->f_namelen = NAME_MAX;
37 * Retaining negative dentries for an in-memory filesystem just wastes
38 * memory and lookup time: arrange for them to be deleted immediately.
40 static int simple_delete_dentry(struct dentry *dentry)
46 * Lookup the data. This is trivial - if the dentry didn't already
47 * exist, we know it is negative. Set d_op to delete negative dentries.
49 struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
51 static const struct dentry_operations simple_dentry_operations = {
52 .d_delete = simple_delete_dentry,
55 if (dentry->d_name.len > NAME_MAX)
56 return ERR_PTR(-ENAMETOOLONG);
57 dentry->d_op = &simple_dentry_operations;
62 int dcache_dir_open(struct inode *inode, struct file *file)
64 static struct qstr cursor_name = {.len = 1, .name = "."};
66 file->private_data = d_alloc(file->f_path.dentry, &cursor_name);
68 return file->private_data ? 0 : -ENOMEM;
71 int dcache_dir_close(struct inode *inode, struct file *file)
73 dput(file->private_data);
77 loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
79 mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
82 offset += file->f_pos;
87 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
90 if (offset != file->f_pos) {
92 if (file->f_pos >= 2) {
94 struct dentry *cursor = file->private_data;
95 loff_t n = file->f_pos - 2;
97 spin_lock(&dcache_lock);
98 list_del(&cursor->d_u.d_child);
99 p = file->f_path.dentry->d_subdirs.next;
100 while (n && p != &file->f_path.dentry->d_subdirs) {
102 next = list_entry(p, struct dentry, d_u.d_child);
103 if (!d_unhashed(next) && next->d_inode)
107 list_add_tail(&cursor->d_u.d_child, p);
108 spin_unlock(&dcache_lock);
111 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
115 /* Relationship between i_mode and the DT_xxx types */
116 static inline unsigned char dt_type(struct inode *inode)
118 return (inode->i_mode >> 12) & 15;
122 * Directory is locked and all positive dentries in it are safe, since
123 * for ramfs-type trees they can't go away without unlink() or rmdir(),
124 * both impossible due to the lock on directory.
127 int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
129 struct dentry *dentry = filp->f_path.dentry;
130 struct dentry *cursor = filp->private_data;
131 struct list_head *p, *q = &cursor->d_u.d_child;
137 ino = dentry->d_inode->i_ino;
138 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
144 ino = parent_ino(dentry);
145 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
151 spin_lock(&dcache_lock);
152 if (filp->f_pos == 2)
153 list_move(q, &dentry->d_subdirs);
155 for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
157 next = list_entry(p, struct dentry, d_u.d_child);
158 if (d_unhashed(next) || !next->d_inode)
161 spin_unlock(&dcache_lock);
162 if (filldir(dirent, next->d_name.name,
163 next->d_name.len, filp->f_pos,
164 next->d_inode->i_ino,
165 dt_type(next->d_inode)) < 0)
167 spin_lock(&dcache_lock);
168 /* next is still alive */
173 spin_unlock(&dcache_lock);
178 ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos)
183 const struct file_operations simple_dir_operations = {
184 .open = dcache_dir_open,
185 .release = dcache_dir_close,
186 .llseek = dcache_dir_lseek,
187 .read = generic_read_dir,
188 .readdir = dcache_readdir,
192 const struct inode_operations simple_dir_inode_operations = {
193 .lookup = simple_lookup,
196 static const struct super_operations simple_super_operations = {
197 .statfs = simple_statfs,
201 * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
202 * will never be mountable)
204 int get_sb_pseudo(struct file_system_type *fs_type, char *name,
205 const struct super_operations *ops, unsigned long magic,
206 struct vfsmount *mnt)
208 struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
209 struct dentry *dentry;
211 struct qstr d_name = {.name = name, .len = strlen(name)};
216 s->s_flags = MS_NOUSER;
217 s->s_maxbytes = MAX_LFS_FILESIZE;
218 s->s_blocksize = PAGE_SIZE;
219 s->s_blocksize_bits = PAGE_SHIFT;
221 s->s_op = ops ? ops : &simple_super_operations;
227 * since this is the first inode, make it number 1. New inodes created
228 * after this must take care not to collide with it (by passing
229 * max_reserved of 1 to iunique).
232 root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
233 root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME;
234 dentry = d_alloc(NULL, &d_name);
240 dentry->d_parent = dentry;
241 d_instantiate(dentry, root);
243 s->s_flags |= MS_ACTIVE;
244 simple_set_mnt(mnt, s);
248 deactivate_locked_super(s);
252 int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
254 struct inode *inode = old_dentry->d_inode;
256 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
258 atomic_inc(&inode->i_count);
260 d_instantiate(dentry, inode);
264 static inline int simple_positive(struct dentry *dentry)
266 return dentry->d_inode && !d_unhashed(dentry);
269 int simple_empty(struct dentry *dentry)
271 struct dentry *child;
274 spin_lock(&dcache_lock);
275 list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
276 if (simple_positive(child))
280 spin_unlock(&dcache_lock);
284 int simple_unlink(struct inode *dir, struct dentry *dentry)
286 struct inode *inode = dentry->d_inode;
288 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
294 int simple_rmdir(struct inode *dir, struct dentry *dentry)
296 if (!simple_empty(dentry))
299 drop_nlink(dentry->d_inode);
300 simple_unlink(dir, dentry);
305 int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
306 struct inode *new_dir, struct dentry *new_dentry)
308 struct inode *inode = old_dentry->d_inode;
309 int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode);
311 if (!simple_empty(new_dentry))
314 if (new_dentry->d_inode) {
315 simple_unlink(new_dir, new_dentry);
318 } else if (they_are_dirs) {
323 old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime =
324 new_dir->i_mtime = inode->i_ctime = CURRENT_TIME;
330 * simple_setsize - handle core mm and vfs requirements for file size change
332 * @newsize: new file size
334 * Returns 0 on success, -error on failure.
336 * simple_setsize must be called with inode_mutex held.
338 * simple_setsize will check that the requested new size is OK (see
339 * inode_newsize_ok), and then will perform the necessary i_size update
340 * and pagecache truncation (if necessary). It will be typically be called
341 * from the filesystem's setattr function when ATTR_SIZE is passed in.
343 * The inode itself must have correct permissions and attributes to allow
344 * i_size to be changed, this function then just checks that the new size
345 * requested is valid.
347 * In the case of simple in-memory filesystems with inodes stored solely
348 * in the inode cache, and file data in the pagecache, nothing more needs
349 * to be done to satisfy a truncate request. Filesystems with on-disk
350 * blocks for example will need to free them in the case of truncate, in
351 * that case it may be easier not to use simple_setsize (but each of its
352 * components will likely be required at some point to update pagecache
355 int simple_setsize(struct inode *inode, loff_t newsize)
360 error = inode_newsize_ok(inode, newsize);
364 oldsize = inode->i_size;
365 i_size_write(inode, newsize);
366 truncate_pagecache(inode, oldsize, newsize);
370 EXPORT_SYMBOL(simple_setsize);
373 * simple_setattr - setattr for simple in-memory filesystem
375 * @iattr: iattr structure
377 * Returns 0 on success, -error on failure.
379 * simple_setattr implements setattr for an in-memory filesystem which
380 * does not store its own file data or metadata (eg. uses the page cache
381 * and inode cache as its data store).
383 int simple_setattr(struct dentry *dentry, struct iattr *iattr)
385 struct inode *inode = dentry->d_inode;
388 error = inode_change_ok(inode, iattr);
392 if (iattr->ia_valid & ATTR_SIZE) {
393 error = simple_setsize(inode, iattr->ia_size);
398 generic_setattr(inode, iattr);
402 EXPORT_SYMBOL(simple_setattr);
404 int simple_readpage(struct file *file, struct page *page)
406 clear_highpage(page);
407 flush_dcache_page(page);
408 SetPageUptodate(page);
413 int simple_write_begin(struct file *file, struct address_space *mapping,
414 loff_t pos, unsigned len, unsigned flags,
415 struct page **pagep, void **fsdata)
420 index = pos >> PAGE_CACHE_SHIFT;
422 page = grab_cache_page_write_begin(mapping, index, flags);
428 if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
429 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
431 zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE);
437 * simple_write_end - .write_end helper for non-block-device FSes
438 * @available: See .write_end of address_space_operations
447 * simple_write_end does the minimum needed for updating a page after writing is
448 * done. It has the same API signature as the .write_end of
449 * address_space_operations vector. So it can just be set onto .write_end for
450 * FSes that don't need any other processing. i_mutex is assumed to be held.
451 * Block based filesystems should use generic_write_end().
452 * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
453 * is not called, so a filesystem that actually does store data in .write_inode
454 * should extend on what's done here with a call to mark_inode_dirty() in the
455 * case that i_size has changed.
457 int simple_write_end(struct file *file, struct address_space *mapping,
458 loff_t pos, unsigned len, unsigned copied,
459 struct page *page, void *fsdata)
461 struct inode *inode = page->mapping->host;
462 loff_t last_pos = pos + copied;
464 /* zero the stale part of the page if we did a short copy */
466 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
468 zero_user(page, from + copied, len - copied);
471 if (!PageUptodate(page))
472 SetPageUptodate(page);
474 * No need to use i_size_read() here, the i_size
475 * cannot change under us because we hold the i_mutex.
477 if (last_pos > inode->i_size)
478 i_size_write(inode, last_pos);
480 set_page_dirty(page);
482 page_cache_release(page);
488 * the inodes created here are not hashed. If you use iunique to generate
489 * unique inode values later for this filesystem, then you must take care
490 * to pass it an appropriate max_reserved value to avoid collisions.
492 int simple_fill_super(struct super_block *s, unsigned long magic,
493 struct tree_descr *files)
497 struct dentry *dentry;
500 s->s_blocksize = PAGE_CACHE_SIZE;
501 s->s_blocksize_bits = PAGE_CACHE_SHIFT;
503 s->s_op = &simple_super_operations;
506 inode = new_inode(s);
510 * because the root inode is 1, the files array must not contain an
514 inode->i_mode = S_IFDIR | 0755;
515 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
516 inode->i_op = &simple_dir_inode_operations;
517 inode->i_fop = &simple_dir_operations;
519 root = d_alloc_root(inode);
524 for (i = 0; !files->name || files->name[0]; i++, files++) {
528 /* warn if it tries to conflict with the root inode */
529 if (unlikely(i == 1))
530 printk(KERN_WARNING "%s: %s passed in a files array"
531 "with an index of 1!\n", __func__,
534 dentry = d_alloc_name(root, files->name);
537 inode = new_inode(s);
540 inode->i_mode = S_IFREG | files->mode;
541 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
542 inode->i_fop = files->ops;
544 d_add(dentry, inode);
554 static DEFINE_SPINLOCK(pin_fs_lock);
556 int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count)
558 struct vfsmount *mnt = NULL;
559 spin_lock(&pin_fs_lock);
560 if (unlikely(!*mount)) {
561 spin_unlock(&pin_fs_lock);
562 mnt = vfs_kern_mount(type, 0, type->name, NULL);
565 spin_lock(&pin_fs_lock);
571 spin_unlock(&pin_fs_lock);
576 void simple_release_fs(struct vfsmount **mount, int *count)
578 struct vfsmount *mnt;
579 spin_lock(&pin_fs_lock);
583 spin_unlock(&pin_fs_lock);
588 * simple_read_from_buffer - copy data from the buffer to user space
589 * @to: the user space buffer to read to
590 * @count: the maximum number of bytes to read
591 * @ppos: the current position in the buffer
592 * @from: the buffer to read from
593 * @available: the size of the buffer
595 * The simple_read_from_buffer() function reads up to @count bytes from the
596 * buffer @from at offset @ppos into the user space address starting at @to.
598 * On success, the number of bytes read is returned and the offset @ppos is
599 * advanced by this number, or negative value is returned on error.
601 ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
602 const void *from, size_t available)
609 if (pos >= available || !count)
611 if (count > available - pos)
612 count = available - pos;
613 ret = copy_to_user(to, from + pos, count);
622 * simple_write_to_buffer - copy data from user space to the buffer
623 * @to: the buffer to write to
624 * @available: the size of the buffer
625 * @ppos: the current position in the buffer
626 * @from: the user space buffer to read from
627 * @count: the maximum number of bytes to read
629 * The simple_write_to_buffer() function reads up to @count bytes from the user
630 * space address starting at @from into the buffer @to at offset @ppos.
632 * On success, the number of bytes written is returned and the offset @ppos is
633 * advanced by this number, or negative value is returned on error.
635 ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
636 const void __user *from, size_t count)
643 if (pos >= available || !count)
645 if (count > available - pos)
646 count = available - pos;
647 res = copy_from_user(to + pos, from, count);
656 * memory_read_from_buffer - copy data from the buffer
657 * @to: the kernel space buffer to read to
658 * @count: the maximum number of bytes to read
659 * @ppos: the current position in the buffer
660 * @from: the buffer to read from
661 * @available: the size of the buffer
663 * The memory_read_from_buffer() function reads up to @count bytes from the
664 * buffer @from at offset @ppos into the kernel space address starting at @to.
666 * On success, the number of bytes read is returned and the offset @ppos is
667 * advanced by this number, or negative value is returned on error.
669 ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
670 const void *from, size_t available)
676 if (pos >= available)
678 if (count > available - pos)
679 count = available - pos;
680 memcpy(to, from + pos, count);
687 * Transaction based IO.
688 * The file expects a single write which triggers the transaction, and then
689 * possibly a read which collects the result - which is stored in a
693 void simple_transaction_set(struct file *file, size_t n)
695 struct simple_transaction_argresp *ar = file->private_data;
697 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT);
700 * The barrier ensures that ar->size will really remain zero until
701 * ar->data is ready for reading.
707 char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
709 struct simple_transaction_argresp *ar;
710 static DEFINE_SPINLOCK(simple_transaction_lock);
712 if (size > SIMPLE_TRANSACTION_LIMIT - 1)
713 return ERR_PTR(-EFBIG);
715 ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
717 return ERR_PTR(-ENOMEM);
719 spin_lock(&simple_transaction_lock);
721 /* only one write allowed per open */
722 if (file->private_data) {
723 spin_unlock(&simple_transaction_lock);
724 free_page((unsigned long)ar);
725 return ERR_PTR(-EBUSY);
728 file->private_data = ar;
730 spin_unlock(&simple_transaction_lock);
732 if (copy_from_user(ar->data, buf, size))
733 return ERR_PTR(-EFAULT);
738 ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
740 struct simple_transaction_argresp *ar = file->private_data;
744 return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
747 int simple_transaction_release(struct inode *inode, struct file *file)
749 free_page((unsigned long)file->private_data);
753 /* Simple attribute files */
756 int (*get)(void *, u64 *);
757 int (*set)(void *, u64);
758 char get_buf[24]; /* enough to store a u64 and "\n\0" */
761 const char *fmt; /* format for read operation */
762 struct mutex mutex; /* protects access to these buffers */
765 /* simple_attr_open is called by an actual attribute open file operation
766 * to set the attribute specific access operations. */
767 int simple_attr_open(struct inode *inode, struct file *file,
768 int (*get)(void *, u64 *), int (*set)(void *, u64),
771 struct simple_attr *attr;
773 attr = kmalloc(sizeof(*attr), GFP_KERNEL);
779 attr->data = inode->i_private;
781 mutex_init(&attr->mutex);
783 file->private_data = attr;
785 return nonseekable_open(inode, file);
788 int simple_attr_release(struct inode *inode, struct file *file)
790 kfree(file->private_data);
794 /* read from the buffer that is filled with the get function */
795 ssize_t simple_attr_read(struct file *file, char __user *buf,
796 size_t len, loff_t *ppos)
798 struct simple_attr *attr;
802 attr = file->private_data;
807 ret = mutex_lock_interruptible(&attr->mutex);
811 if (*ppos) { /* continued read */
812 size = strlen(attr->get_buf);
813 } else { /* first read */
815 ret = attr->get(attr->data, &val);
819 size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
820 attr->fmt, (unsigned long long)val);
823 ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
825 mutex_unlock(&attr->mutex);
829 /* interpret the buffer as a number to call the set function with */
830 ssize_t simple_attr_write(struct file *file, const char __user *buf,
831 size_t len, loff_t *ppos)
833 struct simple_attr *attr;
838 attr = file->private_data;
842 ret = mutex_lock_interruptible(&attr->mutex);
847 size = min(sizeof(attr->set_buf) - 1, len);
848 if (copy_from_user(attr->set_buf, buf, size))
851 attr->set_buf[size] = '\0';
852 val = simple_strtol(attr->set_buf, NULL, 0);
853 ret = attr->set(attr->data, val);
855 ret = len; /* on success, claim we got the whole input */
857 mutex_unlock(&attr->mutex);
862 * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
863 * @sb: filesystem to do the file handle conversion on
864 * @fid: file handle to convert
865 * @fh_len: length of the file handle in bytes
866 * @fh_type: type of file handle
867 * @get_inode: filesystem callback to retrieve inode
869 * This function decodes @fid as long as it has one of the well-known
870 * Linux filehandle types and calls @get_inode on it to retrieve the
871 * inode for the object specified in the file handle.
873 struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid,
874 int fh_len, int fh_type, struct inode *(*get_inode)
875 (struct super_block *sb, u64 ino, u32 gen))
877 struct inode *inode = NULL;
883 case FILEID_INO32_GEN:
884 case FILEID_INO32_GEN_PARENT:
885 inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
889 return d_obtain_alias(inode);
891 EXPORT_SYMBOL_GPL(generic_fh_to_dentry);
894 * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
895 * @sb: filesystem to do the file handle conversion on
896 * @fid: file handle to convert
897 * @fh_len: length of the file handle in bytes
898 * @fh_type: type of file handle
899 * @get_inode: filesystem callback to retrieve inode
901 * This function decodes @fid as long as it has one of the well-known
902 * Linux filehandle types and calls @get_inode on it to retrieve the
903 * inode for the _parent_ object specified in the file handle if it
904 * is specified in the file handle, or NULL otherwise.
906 struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid,
907 int fh_len, int fh_type, struct inode *(*get_inode)
908 (struct super_block *sb, u64 ino, u32 gen))
910 struct inode *inode = NULL;
916 case FILEID_INO32_GEN_PARENT:
917 inode = get_inode(sb, fid->i32.parent_ino,
918 (fh_len > 3 ? fid->i32.parent_gen : 0));
922 return d_obtain_alias(inode);
924 EXPORT_SYMBOL_GPL(generic_fh_to_parent);
927 * generic_file_fsync - generic fsync implementation for simple filesystems
928 * @file: file to synchronize
929 * @datasync: only synchronize essential metadata if true
931 * This is a generic implementation of the fsync method for simple
932 * filesystems which track all non-inode metadata in the buffers list
933 * hanging off the address_space structure.
935 int generic_file_fsync(struct file *file, int datasync)
937 struct writeback_control wbc = {
938 .sync_mode = WB_SYNC_ALL,
939 .nr_to_write = 0, /* metadata-only; caller takes care of data */
941 struct inode *inode = file->f_mapping->host;
945 ret = sync_mapping_buffers(inode->i_mapping);
946 if (!(inode->i_state & I_DIRTY))
948 if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
951 err = sync_inode(inode, &wbc);
956 EXPORT_SYMBOL(generic_file_fsync);
959 * No-op implementation of ->fsync for in-memory filesystems.
961 int noop_fsync(struct file *file, int datasync)
966 EXPORT_SYMBOL(dcache_dir_close);
967 EXPORT_SYMBOL(dcache_dir_lseek);
968 EXPORT_SYMBOL(dcache_dir_open);
969 EXPORT_SYMBOL(dcache_readdir);
970 EXPORT_SYMBOL(generic_read_dir);
971 EXPORT_SYMBOL(get_sb_pseudo);
972 EXPORT_SYMBOL(simple_write_begin);
973 EXPORT_SYMBOL(simple_write_end);
974 EXPORT_SYMBOL(simple_dir_inode_operations);
975 EXPORT_SYMBOL(simple_dir_operations);
976 EXPORT_SYMBOL(simple_empty);
977 EXPORT_SYMBOL(simple_fill_super);
978 EXPORT_SYMBOL(simple_getattr);
979 EXPORT_SYMBOL(simple_link);
980 EXPORT_SYMBOL(simple_lookup);
981 EXPORT_SYMBOL(simple_pin_fs);
982 EXPORT_SYMBOL(simple_readpage);
983 EXPORT_SYMBOL(simple_release_fs);
984 EXPORT_SYMBOL(simple_rename);
985 EXPORT_SYMBOL(simple_rmdir);
986 EXPORT_SYMBOL(simple_statfs);
987 EXPORT_SYMBOL(noop_fsync);
988 EXPORT_SYMBOL(simple_unlink);
989 EXPORT_SYMBOL(simple_read_from_buffer);
990 EXPORT_SYMBOL(simple_write_to_buffer);
991 EXPORT_SYMBOL(memory_read_from_buffer);
992 EXPORT_SYMBOL(simple_transaction_set);
993 EXPORT_SYMBOL(simple_transaction_get);
994 EXPORT_SYMBOL(simple_transaction_read);
995 EXPORT_SYMBOL(simple_transaction_release);
996 EXPORT_SYMBOL_GPL(simple_attr_open);
997 EXPORT_SYMBOL_GPL(simple_attr_release);
998 EXPORT_SYMBOL_GPL(simple_attr_read);
999 EXPORT_SYMBOL_GPL(simple_attr_write);