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 static inline int simple_positive(struct dentry
*dentry
)
21 return dentry
->d_inode
&& !d_unhashed(dentry
);
24 int simple_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
27 struct inode
*inode
= dentry
->d_inode
;
28 generic_fillattr(inode
, stat
);
29 stat
->blocks
= inode
->i_mapping
->nrpages
<< (PAGE_CACHE_SHIFT
- 9);
33 int simple_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
35 buf
->f_type
= dentry
->d_sb
->s_magic
;
36 buf
->f_bsize
= PAGE_CACHE_SIZE
;
37 buf
->f_namelen
= NAME_MAX
;
42 * Retaining negative dentries for an in-memory filesystem just wastes
43 * memory and lookup time: arrange for them to be deleted immediately.
45 static int simple_delete_dentry(const struct dentry
*dentry
)
51 * Lookup the data. This is trivial - if the dentry didn't already
52 * exist, we know it is negative. Set d_op to delete negative dentries.
54 struct dentry
*simple_lookup(struct inode
*dir
, struct dentry
*dentry
, struct nameidata
*nd
)
56 static const struct dentry_operations simple_dentry_operations
= {
57 .d_delete
= simple_delete_dentry
,
60 if (dentry
->d_name
.len
> NAME_MAX
)
61 return ERR_PTR(-ENAMETOOLONG
);
62 dentry
->d_op
= &simple_dentry_operations
;
67 int dcache_dir_open(struct inode
*inode
, struct file
*file
)
69 static struct qstr cursor_name
= {.len
= 1, .name
= "."};
71 file
->private_data
= d_alloc(file
->f_path
.dentry
, &cursor_name
);
73 return file
->private_data
? 0 : -ENOMEM
;
76 int dcache_dir_close(struct inode
*inode
, struct file
*file
)
78 dput(file
->private_data
);
82 loff_t
dcache_dir_lseek(struct file
*file
, loff_t offset
, int origin
)
84 mutex_lock(&file
->f_path
.dentry
->d_inode
->i_mutex
);
87 offset
+= file
->f_pos
;
92 mutex_unlock(&file
->f_path
.dentry
->d_inode
->i_mutex
);
95 if (offset
!= file
->f_pos
) {
97 if (file
->f_pos
>= 2) {
99 struct dentry
*cursor
= file
->private_data
;
100 loff_t n
= file
->f_pos
- 2;
102 spin_lock(&dcache_lock
);
103 list_del(&cursor
->d_u
.d_child
);
104 p
= file
->f_path
.dentry
->d_subdirs
.next
;
105 while (n
&& p
!= &file
->f_path
.dentry
->d_subdirs
) {
107 next
= list_entry(p
, struct dentry
, d_u
.d_child
);
108 spin_lock(&next
->d_lock
);
109 if (simple_positive(next
))
111 spin_unlock(&next
->d_lock
);
114 list_add_tail(&cursor
->d_u
.d_child
, p
);
115 spin_unlock(&dcache_lock
);
118 mutex_unlock(&file
->f_path
.dentry
->d_inode
->i_mutex
);
122 /* Relationship between i_mode and the DT_xxx types */
123 static inline unsigned char dt_type(struct inode
*inode
)
125 return (inode
->i_mode
>> 12) & 15;
129 * Directory is locked and all positive dentries in it are safe, since
130 * for ramfs-type trees they can't go away without unlink() or rmdir(),
131 * both impossible due to the lock on directory.
134 int dcache_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
136 struct dentry
*dentry
= filp
->f_path
.dentry
;
137 struct dentry
*cursor
= filp
->private_data
;
138 struct list_head
*p
, *q
= &cursor
->d_u
.d_child
;
144 ino
= dentry
->d_inode
->i_ino
;
145 if (filldir(dirent
, ".", 1, i
, ino
, DT_DIR
) < 0)
151 ino
= parent_ino(dentry
);
152 if (filldir(dirent
, "..", 2, i
, ino
, DT_DIR
) < 0)
158 spin_lock(&dcache_lock
);
159 if (filp
->f_pos
== 2)
160 list_move(q
, &dentry
->d_subdirs
);
162 for (p
=q
->next
; p
!= &dentry
->d_subdirs
; p
=p
->next
) {
164 next
= list_entry(p
, struct dentry
, d_u
.d_child
);
165 spin_lock_nested(&next
->d_lock
, DENTRY_D_LOCK_NESTED
);
166 if (!simple_positive(next
)) {
167 spin_unlock(&next
->d_lock
);
171 spin_unlock(&next
->d_lock
);
172 spin_unlock(&dcache_lock
);
173 if (filldir(dirent
, next
->d_name
.name
,
174 next
->d_name
.len
, filp
->f_pos
,
175 next
->d_inode
->i_ino
,
176 dt_type(next
->d_inode
)) < 0)
178 spin_lock(&dcache_lock
);
179 /* next is still alive */
184 spin_unlock(&dcache_lock
);
189 ssize_t
generic_read_dir(struct file
*filp
, char __user
*buf
, size_t siz
, loff_t
*ppos
)
194 const struct file_operations simple_dir_operations
= {
195 .open
= dcache_dir_open
,
196 .release
= dcache_dir_close
,
197 .llseek
= dcache_dir_lseek
,
198 .read
= generic_read_dir
,
199 .readdir
= dcache_readdir
,
203 const struct inode_operations simple_dir_inode_operations
= {
204 .lookup
= simple_lookup
,
207 static const struct super_operations simple_super_operations
= {
208 .statfs
= simple_statfs
,
212 * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
213 * will never be mountable)
215 struct dentry
*mount_pseudo(struct file_system_type
*fs_type
, char *name
,
216 const struct super_operations
*ops
, unsigned long magic
)
218 struct super_block
*s
= sget(fs_type
, NULL
, set_anon_super
, NULL
);
219 struct dentry
*dentry
;
221 struct qstr d_name
= {.name
= name
, .len
= strlen(name
)};
226 s
->s_flags
= MS_NOUSER
;
227 s
->s_maxbytes
= MAX_LFS_FILESIZE
;
228 s
->s_blocksize
= PAGE_SIZE
;
229 s
->s_blocksize_bits
= PAGE_SHIFT
;
231 s
->s_op
= ops
? ops
: &simple_super_operations
;
237 * since this is the first inode, make it number 1. New inodes created
238 * after this must take care not to collide with it (by passing
239 * max_reserved of 1 to iunique).
242 root
->i_mode
= S_IFDIR
| S_IRUSR
| S_IWUSR
;
243 root
->i_atime
= root
->i_mtime
= root
->i_ctime
= CURRENT_TIME
;
244 dentry
= d_alloc(NULL
, &d_name
);
250 dentry
->d_parent
= dentry
;
251 d_instantiate(dentry
, root
);
253 s
->s_flags
|= MS_ACTIVE
;
254 return dget(s
->s_root
);
257 deactivate_locked_super(s
);
258 return ERR_PTR(-ENOMEM
);
261 int simple_link(struct dentry
*old_dentry
, struct inode
*dir
, struct dentry
*dentry
)
263 struct inode
*inode
= old_dentry
->d_inode
;
265 inode
->i_ctime
= dir
->i_ctime
= dir
->i_mtime
= CURRENT_TIME
;
269 d_instantiate(dentry
, inode
);
273 int simple_empty(struct dentry
*dentry
)
275 struct dentry
*child
;
278 spin_lock(&dcache_lock
);
279 list_for_each_entry(child
, &dentry
->d_subdirs
, d_u
.d_child
) {
280 spin_lock_nested(&child
->d_lock
, DENTRY_D_LOCK_NESTED
);
281 if (simple_positive(child
)) {
282 spin_unlock(&child
->d_lock
);
285 spin_unlock(&child
->d_lock
);
289 spin_unlock(&dcache_lock
);
293 int simple_unlink(struct inode
*dir
, struct dentry
*dentry
)
295 struct inode
*inode
= dentry
->d_inode
;
297 inode
->i_ctime
= dir
->i_ctime
= dir
->i_mtime
= CURRENT_TIME
;
303 int simple_rmdir(struct inode
*dir
, struct dentry
*dentry
)
305 if (!simple_empty(dentry
))
308 drop_nlink(dentry
->d_inode
);
309 simple_unlink(dir
, dentry
);
314 int simple_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
315 struct inode
*new_dir
, struct dentry
*new_dentry
)
317 struct inode
*inode
= old_dentry
->d_inode
;
318 int they_are_dirs
= S_ISDIR(old_dentry
->d_inode
->i_mode
);
320 if (!simple_empty(new_dentry
))
323 if (new_dentry
->d_inode
) {
324 simple_unlink(new_dir
, new_dentry
);
327 } else if (they_are_dirs
) {
332 old_dir
->i_ctime
= old_dir
->i_mtime
= new_dir
->i_ctime
=
333 new_dir
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
339 * simple_setattr - setattr for simple filesystem
341 * @iattr: iattr structure
343 * Returns 0 on success, -error on failure.
345 * simple_setattr is a simple ->setattr implementation without a proper
346 * implementation of size changes.
348 * It can either be used for in-memory filesystems or special files
349 * on simple regular filesystems. Anything that needs to change on-disk
350 * or wire state on size changes needs its own setattr method.
352 int simple_setattr(struct dentry
*dentry
, struct iattr
*iattr
)
354 struct inode
*inode
= dentry
->d_inode
;
357 WARN_ON_ONCE(inode
->i_op
->truncate
);
359 error
= inode_change_ok(inode
, iattr
);
363 if (iattr
->ia_valid
& ATTR_SIZE
)
364 truncate_setsize(inode
, iattr
->ia_size
);
365 setattr_copy(inode
, iattr
);
366 mark_inode_dirty(inode
);
369 EXPORT_SYMBOL(simple_setattr
);
371 int simple_readpage(struct file
*file
, struct page
*page
)
373 clear_highpage(page
);
374 flush_dcache_page(page
);
375 SetPageUptodate(page
);
380 int simple_write_begin(struct file
*file
, struct address_space
*mapping
,
381 loff_t pos
, unsigned len
, unsigned flags
,
382 struct page
**pagep
, void **fsdata
)
387 index
= pos
>> PAGE_CACHE_SHIFT
;
389 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
395 if (!PageUptodate(page
) && (len
!= PAGE_CACHE_SIZE
)) {
396 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
398 zero_user_segments(page
, 0, from
, from
+ len
, PAGE_CACHE_SIZE
);
404 * simple_write_end - .write_end helper for non-block-device FSes
405 * @available: See .write_end of address_space_operations
414 * simple_write_end does the minimum needed for updating a page after writing is
415 * done. It has the same API signature as the .write_end of
416 * address_space_operations vector. So it can just be set onto .write_end for
417 * FSes that don't need any other processing. i_mutex is assumed to be held.
418 * Block based filesystems should use generic_write_end().
419 * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
420 * is not called, so a filesystem that actually does store data in .write_inode
421 * should extend on what's done here with a call to mark_inode_dirty() in the
422 * case that i_size has changed.
424 int simple_write_end(struct file
*file
, struct address_space
*mapping
,
425 loff_t pos
, unsigned len
, unsigned copied
,
426 struct page
*page
, void *fsdata
)
428 struct inode
*inode
= page
->mapping
->host
;
429 loff_t last_pos
= pos
+ copied
;
431 /* zero the stale part of the page if we did a short copy */
433 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
435 zero_user(page
, from
+ copied
, len
- copied
);
438 if (!PageUptodate(page
))
439 SetPageUptodate(page
);
441 * No need to use i_size_read() here, the i_size
442 * cannot change under us because we hold the i_mutex.
444 if (last_pos
> inode
->i_size
)
445 i_size_write(inode
, last_pos
);
447 set_page_dirty(page
);
449 page_cache_release(page
);
455 * the inodes created here are not hashed. If you use iunique to generate
456 * unique inode values later for this filesystem, then you must take care
457 * to pass it an appropriate max_reserved value to avoid collisions.
459 int simple_fill_super(struct super_block
*s
, unsigned long magic
,
460 struct tree_descr
*files
)
464 struct dentry
*dentry
;
467 s
->s_blocksize
= PAGE_CACHE_SIZE
;
468 s
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
470 s
->s_op
= &simple_super_operations
;
473 inode
= new_inode(s
);
477 * because the root inode is 1, the files array must not contain an
481 inode
->i_mode
= S_IFDIR
| 0755;
482 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
483 inode
->i_op
= &simple_dir_inode_operations
;
484 inode
->i_fop
= &simple_dir_operations
;
486 root
= d_alloc_root(inode
);
491 for (i
= 0; !files
->name
|| files
->name
[0]; i
++, files
++) {
495 /* warn if it tries to conflict with the root inode */
496 if (unlikely(i
== 1))
497 printk(KERN_WARNING
"%s: %s passed in a files array"
498 "with an index of 1!\n", __func__
,
501 dentry
= d_alloc_name(root
, files
->name
);
504 inode
= new_inode(s
);
507 inode
->i_mode
= S_IFREG
| files
->mode
;
508 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
509 inode
->i_fop
= files
->ops
;
511 d_add(dentry
, inode
);
521 static DEFINE_SPINLOCK(pin_fs_lock
);
523 int simple_pin_fs(struct file_system_type
*type
, struct vfsmount
**mount
, int *count
)
525 struct vfsmount
*mnt
= NULL
;
526 spin_lock(&pin_fs_lock
);
527 if (unlikely(!*mount
)) {
528 spin_unlock(&pin_fs_lock
);
529 mnt
= vfs_kern_mount(type
, 0, type
->name
, NULL
);
532 spin_lock(&pin_fs_lock
);
538 spin_unlock(&pin_fs_lock
);
543 void simple_release_fs(struct vfsmount
**mount
, int *count
)
545 struct vfsmount
*mnt
;
546 spin_lock(&pin_fs_lock
);
550 spin_unlock(&pin_fs_lock
);
555 * simple_read_from_buffer - copy data from the buffer to user space
556 * @to: the user space buffer to read to
557 * @count: the maximum number of bytes to read
558 * @ppos: the current position in the buffer
559 * @from: the buffer to read from
560 * @available: the size of the buffer
562 * The simple_read_from_buffer() function reads up to @count bytes from the
563 * buffer @from at offset @ppos into the user space address starting at @to.
565 * On success, the number of bytes read is returned and the offset @ppos is
566 * advanced by this number, or negative value is returned on error.
568 ssize_t
simple_read_from_buffer(void __user
*to
, size_t count
, loff_t
*ppos
,
569 const void *from
, size_t available
)
576 if (pos
>= available
|| !count
)
578 if (count
> available
- pos
)
579 count
= available
- pos
;
580 ret
= copy_to_user(to
, from
+ pos
, count
);
589 * simple_write_to_buffer - copy data from user space to the buffer
590 * @to: the buffer to write to
591 * @available: the size of the buffer
592 * @ppos: the current position in the buffer
593 * @from: the user space buffer to read from
594 * @count: the maximum number of bytes to read
596 * The simple_write_to_buffer() function reads up to @count bytes from the user
597 * space address starting at @from into the buffer @to at offset @ppos.
599 * On success, the number of bytes written is returned and the offset @ppos is
600 * advanced by this number, or negative value is returned on error.
602 ssize_t
simple_write_to_buffer(void *to
, size_t available
, loff_t
*ppos
,
603 const void __user
*from
, size_t count
)
610 if (pos
>= available
|| !count
)
612 if (count
> available
- pos
)
613 count
= available
- pos
;
614 res
= copy_from_user(to
+ pos
, from
, count
);
623 * memory_read_from_buffer - copy data from the buffer
624 * @to: the kernel space buffer to read to
625 * @count: the maximum number of bytes to read
626 * @ppos: the current position in the buffer
627 * @from: the buffer to read from
628 * @available: the size of the buffer
630 * The memory_read_from_buffer() function reads up to @count bytes from the
631 * buffer @from at offset @ppos into the kernel space address starting at @to.
633 * On success, the number of bytes read is returned and the offset @ppos is
634 * advanced by this number, or negative value is returned on error.
636 ssize_t
memory_read_from_buffer(void *to
, size_t count
, loff_t
*ppos
,
637 const void *from
, size_t available
)
643 if (pos
>= available
)
645 if (count
> available
- pos
)
646 count
= available
- pos
;
647 memcpy(to
, from
+ pos
, count
);
654 * Transaction based IO.
655 * The file expects a single write which triggers the transaction, and then
656 * possibly a read which collects the result - which is stored in a
660 void simple_transaction_set(struct file
*file
, size_t n
)
662 struct simple_transaction_argresp
*ar
= file
->private_data
;
664 BUG_ON(n
> SIMPLE_TRANSACTION_LIMIT
);
667 * The barrier ensures that ar->size will really remain zero until
668 * ar->data is ready for reading.
674 char *simple_transaction_get(struct file
*file
, const char __user
*buf
, size_t size
)
676 struct simple_transaction_argresp
*ar
;
677 static DEFINE_SPINLOCK(simple_transaction_lock
);
679 if (size
> SIMPLE_TRANSACTION_LIMIT
- 1)
680 return ERR_PTR(-EFBIG
);
682 ar
= (struct simple_transaction_argresp
*)get_zeroed_page(GFP_KERNEL
);
684 return ERR_PTR(-ENOMEM
);
686 spin_lock(&simple_transaction_lock
);
688 /* only one write allowed per open */
689 if (file
->private_data
) {
690 spin_unlock(&simple_transaction_lock
);
691 free_page((unsigned long)ar
);
692 return ERR_PTR(-EBUSY
);
695 file
->private_data
= ar
;
697 spin_unlock(&simple_transaction_lock
);
699 if (copy_from_user(ar
->data
, buf
, size
))
700 return ERR_PTR(-EFAULT
);
705 ssize_t
simple_transaction_read(struct file
*file
, char __user
*buf
, size_t size
, loff_t
*pos
)
707 struct simple_transaction_argresp
*ar
= file
->private_data
;
711 return simple_read_from_buffer(buf
, size
, pos
, ar
->data
, ar
->size
);
714 int simple_transaction_release(struct inode
*inode
, struct file
*file
)
716 free_page((unsigned long)file
->private_data
);
720 /* Simple attribute files */
723 int (*get
)(void *, u64
*);
724 int (*set
)(void *, u64
);
725 char get_buf
[24]; /* enough to store a u64 and "\n\0" */
728 const char *fmt
; /* format for read operation */
729 struct mutex mutex
; /* protects access to these buffers */
732 /* simple_attr_open is called by an actual attribute open file operation
733 * to set the attribute specific access operations. */
734 int simple_attr_open(struct inode
*inode
, struct file
*file
,
735 int (*get
)(void *, u64
*), int (*set
)(void *, u64
),
738 struct simple_attr
*attr
;
740 attr
= kmalloc(sizeof(*attr
), GFP_KERNEL
);
746 attr
->data
= inode
->i_private
;
748 mutex_init(&attr
->mutex
);
750 file
->private_data
= attr
;
752 return nonseekable_open(inode
, file
);
755 int simple_attr_release(struct inode
*inode
, struct file
*file
)
757 kfree(file
->private_data
);
761 /* read from the buffer that is filled with the get function */
762 ssize_t
simple_attr_read(struct file
*file
, char __user
*buf
,
763 size_t len
, loff_t
*ppos
)
765 struct simple_attr
*attr
;
769 attr
= file
->private_data
;
774 ret
= mutex_lock_interruptible(&attr
->mutex
);
778 if (*ppos
) { /* continued read */
779 size
= strlen(attr
->get_buf
);
780 } else { /* first read */
782 ret
= attr
->get(attr
->data
, &val
);
786 size
= scnprintf(attr
->get_buf
, sizeof(attr
->get_buf
),
787 attr
->fmt
, (unsigned long long)val
);
790 ret
= simple_read_from_buffer(buf
, len
, ppos
, attr
->get_buf
, size
);
792 mutex_unlock(&attr
->mutex
);
796 /* interpret the buffer as a number to call the set function with */
797 ssize_t
simple_attr_write(struct file
*file
, const char __user
*buf
,
798 size_t len
, loff_t
*ppos
)
800 struct simple_attr
*attr
;
805 attr
= file
->private_data
;
809 ret
= mutex_lock_interruptible(&attr
->mutex
);
814 size
= min(sizeof(attr
->set_buf
) - 1, len
);
815 if (copy_from_user(attr
->set_buf
, buf
, size
))
818 attr
->set_buf
[size
] = '\0';
819 val
= simple_strtol(attr
->set_buf
, NULL
, 0);
820 ret
= attr
->set(attr
->data
, val
);
822 ret
= len
; /* on success, claim we got the whole input */
824 mutex_unlock(&attr
->mutex
);
829 * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
830 * @sb: filesystem to do the file handle conversion on
831 * @fid: file handle to convert
832 * @fh_len: length of the file handle in bytes
833 * @fh_type: type of file handle
834 * @get_inode: filesystem callback to retrieve inode
836 * This function decodes @fid as long as it has one of the well-known
837 * Linux filehandle types and calls @get_inode on it to retrieve the
838 * inode for the object specified in the file handle.
840 struct dentry
*generic_fh_to_dentry(struct super_block
*sb
, struct fid
*fid
,
841 int fh_len
, int fh_type
, struct inode
*(*get_inode
)
842 (struct super_block
*sb
, u64 ino
, u32 gen
))
844 struct inode
*inode
= NULL
;
850 case FILEID_INO32_GEN
:
851 case FILEID_INO32_GEN_PARENT
:
852 inode
= get_inode(sb
, fid
->i32
.ino
, fid
->i32
.gen
);
856 return d_obtain_alias(inode
);
858 EXPORT_SYMBOL_GPL(generic_fh_to_dentry
);
861 * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
862 * @sb: filesystem to do the file handle conversion on
863 * @fid: file handle to convert
864 * @fh_len: length of the file handle in bytes
865 * @fh_type: type of file handle
866 * @get_inode: filesystem callback to retrieve inode
868 * This function decodes @fid as long as it has one of the well-known
869 * Linux filehandle types and calls @get_inode on it to retrieve the
870 * inode for the _parent_ object specified in the file handle if it
871 * is specified in the file handle, or NULL otherwise.
873 struct dentry
*generic_fh_to_parent(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_PARENT
:
884 inode
= get_inode(sb
, fid
->i32
.parent_ino
,
885 (fh_len
> 3 ? fid
->i32
.parent_gen
: 0));
889 return d_obtain_alias(inode
);
891 EXPORT_SYMBOL_GPL(generic_fh_to_parent
);
894 * generic_file_fsync - generic fsync implementation for simple filesystems
895 * @file: file to synchronize
896 * @datasync: only synchronize essential metadata if true
898 * This is a generic implementation of the fsync method for simple
899 * filesystems which track all non-inode metadata in the buffers list
900 * hanging off the address_space structure.
902 int generic_file_fsync(struct file
*file
, int datasync
)
904 struct inode
*inode
= file
->f_mapping
->host
;
908 ret
= sync_mapping_buffers(inode
->i_mapping
);
909 if (!(inode
->i_state
& I_DIRTY
))
911 if (datasync
&& !(inode
->i_state
& I_DIRTY_DATASYNC
))
914 err
= sync_inode_metadata(inode
, 1);
919 EXPORT_SYMBOL(generic_file_fsync
);
922 * generic_check_addressable - Check addressability of file system
923 * @blocksize_bits: log of file system block size
924 * @num_blocks: number of blocks in file system
926 * Determine whether a file system with @num_blocks blocks (and a
927 * block size of 2**@blocksize_bits) is addressable by the sector_t
928 * and page cache of the system. Return 0 if so and -EFBIG otherwise.
930 int generic_check_addressable(unsigned blocksize_bits
, u64 num_blocks
)
932 u64 last_fs_block
= num_blocks
- 1;
934 last_fs_block
>> (PAGE_CACHE_SHIFT
- blocksize_bits
);
936 if (unlikely(num_blocks
== 0))
939 if ((blocksize_bits
< 9) || (blocksize_bits
> PAGE_CACHE_SHIFT
))
942 if ((last_fs_block
> (sector_t
)(~0ULL) >> (blocksize_bits
- 9)) ||
943 (last_fs_page
> (pgoff_t
)(~0ULL))) {
948 EXPORT_SYMBOL(generic_check_addressable
);
951 * No-op implementation of ->fsync for in-memory filesystems.
953 int noop_fsync(struct file
*file
, int datasync
)
958 EXPORT_SYMBOL(dcache_dir_close
);
959 EXPORT_SYMBOL(dcache_dir_lseek
);
960 EXPORT_SYMBOL(dcache_dir_open
);
961 EXPORT_SYMBOL(dcache_readdir
);
962 EXPORT_SYMBOL(generic_read_dir
);
963 EXPORT_SYMBOL(mount_pseudo
);
964 EXPORT_SYMBOL(simple_write_begin
);
965 EXPORT_SYMBOL(simple_write_end
);
966 EXPORT_SYMBOL(simple_dir_inode_operations
);
967 EXPORT_SYMBOL(simple_dir_operations
);
968 EXPORT_SYMBOL(simple_empty
);
969 EXPORT_SYMBOL(simple_fill_super
);
970 EXPORT_SYMBOL(simple_getattr
);
971 EXPORT_SYMBOL(simple_link
);
972 EXPORT_SYMBOL(simple_lookup
);
973 EXPORT_SYMBOL(simple_pin_fs
);
974 EXPORT_SYMBOL(simple_readpage
);
975 EXPORT_SYMBOL(simple_release_fs
);
976 EXPORT_SYMBOL(simple_rename
);
977 EXPORT_SYMBOL(simple_rmdir
);
978 EXPORT_SYMBOL(simple_statfs
);
979 EXPORT_SYMBOL(noop_fsync
);
980 EXPORT_SYMBOL(simple_unlink
);
981 EXPORT_SYMBOL(simple_read_from_buffer
);
982 EXPORT_SYMBOL(simple_write_to_buffer
);
983 EXPORT_SYMBOL(memory_read_from_buffer
);
984 EXPORT_SYMBOL(simple_transaction_set
);
985 EXPORT_SYMBOL(simple_transaction_get
);
986 EXPORT_SYMBOL(simple_transaction_read
);
987 EXPORT_SYMBOL(simple_transaction_release
);
988 EXPORT_SYMBOL_GPL(simple_attr_open
);
989 EXPORT_SYMBOL_GPL(simple_attr_release
);
990 EXPORT_SYMBOL_GPL(simple_attr_read
);
991 EXPORT_SYMBOL_GPL(simple_attr_write
);