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 struct dentry
*dentry
= file
->f_path
.dentry
;
85 mutex_lock(&dentry
->d_inode
->i_mutex
);
88 offset
+= file
->f_pos
;
93 mutex_unlock(&dentry
->d_inode
->i_mutex
);
96 if (offset
!= file
->f_pos
) {
98 if (file
->f_pos
>= 2) {
100 struct dentry
*cursor
= file
->private_data
;
101 loff_t n
= file
->f_pos
- 2;
103 spin_lock(&dcache_lock
);
104 spin_lock(&dentry
->d_lock
);
105 /* d_lock not required for cursor */
106 list_del(&cursor
->d_u
.d_child
);
107 p
= dentry
->d_subdirs
.next
;
108 while (n
&& p
!= &dentry
->d_subdirs
) {
110 next
= list_entry(p
, struct dentry
, d_u
.d_child
);
111 spin_lock_nested(&next
->d_lock
, DENTRY_D_LOCK_NESTED
);
112 if (simple_positive(next
))
114 spin_unlock(&next
->d_lock
);
117 list_add_tail(&cursor
->d_u
.d_child
, p
);
118 spin_unlock(&dentry
->d_lock
);
119 spin_unlock(&dcache_lock
);
122 mutex_unlock(&dentry
->d_inode
->i_mutex
);
126 /* Relationship between i_mode and the DT_xxx types */
127 static inline unsigned char dt_type(struct inode
*inode
)
129 return (inode
->i_mode
>> 12) & 15;
133 * Directory is locked and all positive dentries in it are safe, since
134 * for ramfs-type trees they can't go away without unlink() or rmdir(),
135 * both impossible due to the lock on directory.
138 int dcache_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
140 struct dentry
*dentry
= filp
->f_path
.dentry
;
141 struct dentry
*cursor
= filp
->private_data
;
142 struct list_head
*p
, *q
= &cursor
->d_u
.d_child
;
148 ino
= dentry
->d_inode
->i_ino
;
149 if (filldir(dirent
, ".", 1, i
, ino
, DT_DIR
) < 0)
155 ino
= parent_ino(dentry
);
156 if (filldir(dirent
, "..", 2, i
, ino
, DT_DIR
) < 0)
162 spin_lock(&dcache_lock
);
163 spin_lock(&dentry
->d_lock
);
164 if (filp
->f_pos
== 2)
165 list_move(q
, &dentry
->d_subdirs
);
167 for (p
=q
->next
; p
!= &dentry
->d_subdirs
; p
=p
->next
) {
169 next
= list_entry(p
, struct dentry
, d_u
.d_child
);
170 spin_lock_nested(&next
->d_lock
, DENTRY_D_LOCK_NESTED
);
171 if (!simple_positive(next
)) {
172 spin_unlock(&next
->d_lock
);
176 spin_unlock(&next
->d_lock
);
177 spin_unlock(&dentry
->d_lock
);
178 spin_unlock(&dcache_lock
);
179 if (filldir(dirent
, next
->d_name
.name
,
180 next
->d_name
.len
, filp
->f_pos
,
181 next
->d_inode
->i_ino
,
182 dt_type(next
->d_inode
)) < 0)
184 spin_lock(&dcache_lock
);
185 spin_lock(&dentry
->d_lock
);
186 spin_lock_nested(&next
->d_lock
, DENTRY_D_LOCK_NESTED
);
187 /* next is still alive */
189 spin_unlock(&next
->d_lock
);
193 spin_unlock(&dentry
->d_lock
);
194 spin_unlock(&dcache_lock
);
199 ssize_t
generic_read_dir(struct file
*filp
, char __user
*buf
, size_t siz
, loff_t
*ppos
)
204 const struct file_operations simple_dir_operations
= {
205 .open
= dcache_dir_open
,
206 .release
= dcache_dir_close
,
207 .llseek
= dcache_dir_lseek
,
208 .read
= generic_read_dir
,
209 .readdir
= dcache_readdir
,
213 const struct inode_operations simple_dir_inode_operations
= {
214 .lookup
= simple_lookup
,
217 static const struct super_operations simple_super_operations
= {
218 .statfs
= simple_statfs
,
222 * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
223 * will never be mountable)
225 struct dentry
*mount_pseudo(struct file_system_type
*fs_type
, char *name
,
226 const struct super_operations
*ops
, unsigned long magic
)
228 struct super_block
*s
= sget(fs_type
, NULL
, set_anon_super
, NULL
);
229 struct dentry
*dentry
;
231 struct qstr d_name
= {.name
= name
, .len
= strlen(name
)};
236 s
->s_flags
= MS_NOUSER
;
237 s
->s_maxbytes
= MAX_LFS_FILESIZE
;
238 s
->s_blocksize
= PAGE_SIZE
;
239 s
->s_blocksize_bits
= PAGE_SHIFT
;
241 s
->s_op
= ops
? ops
: &simple_super_operations
;
247 * since this is the first inode, make it number 1. New inodes created
248 * after this must take care not to collide with it (by passing
249 * max_reserved of 1 to iunique).
252 root
->i_mode
= S_IFDIR
| S_IRUSR
| S_IWUSR
;
253 root
->i_atime
= root
->i_mtime
= root
->i_ctime
= CURRENT_TIME
;
254 dentry
= d_alloc(NULL
, &d_name
);
260 dentry
->d_parent
= dentry
;
261 d_instantiate(dentry
, root
);
263 s
->s_flags
|= MS_ACTIVE
;
264 return dget(s
->s_root
);
267 deactivate_locked_super(s
);
268 return ERR_PTR(-ENOMEM
);
271 int simple_link(struct dentry
*old_dentry
, struct inode
*dir
, struct dentry
*dentry
)
273 struct inode
*inode
= old_dentry
->d_inode
;
275 inode
->i_ctime
= dir
->i_ctime
= dir
->i_mtime
= CURRENT_TIME
;
279 d_instantiate(dentry
, inode
);
283 int simple_empty(struct dentry
*dentry
)
285 struct dentry
*child
;
288 spin_lock(&dcache_lock
);
289 spin_lock(&dentry
->d_lock
);
290 list_for_each_entry(child
, &dentry
->d_subdirs
, d_u
.d_child
) {
291 spin_lock_nested(&child
->d_lock
, DENTRY_D_LOCK_NESTED
);
292 if (simple_positive(child
)) {
293 spin_unlock(&child
->d_lock
);
296 spin_unlock(&child
->d_lock
);
300 spin_unlock(&dentry
->d_lock
);
301 spin_unlock(&dcache_lock
);
305 int simple_unlink(struct inode
*dir
, struct dentry
*dentry
)
307 struct inode
*inode
= dentry
->d_inode
;
309 inode
->i_ctime
= dir
->i_ctime
= dir
->i_mtime
= CURRENT_TIME
;
315 int simple_rmdir(struct inode
*dir
, struct dentry
*dentry
)
317 if (!simple_empty(dentry
))
320 drop_nlink(dentry
->d_inode
);
321 simple_unlink(dir
, dentry
);
326 int simple_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
327 struct inode
*new_dir
, struct dentry
*new_dentry
)
329 struct inode
*inode
= old_dentry
->d_inode
;
330 int they_are_dirs
= S_ISDIR(old_dentry
->d_inode
->i_mode
);
332 if (!simple_empty(new_dentry
))
335 if (new_dentry
->d_inode
) {
336 simple_unlink(new_dir
, new_dentry
);
339 } else if (they_are_dirs
) {
344 old_dir
->i_ctime
= old_dir
->i_mtime
= new_dir
->i_ctime
=
345 new_dir
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
351 * simple_setattr - setattr for simple filesystem
353 * @iattr: iattr structure
355 * Returns 0 on success, -error on failure.
357 * simple_setattr is a simple ->setattr implementation without a proper
358 * implementation of size changes.
360 * It can either be used for in-memory filesystems or special files
361 * on simple regular filesystems. Anything that needs to change on-disk
362 * or wire state on size changes needs its own setattr method.
364 int simple_setattr(struct dentry
*dentry
, struct iattr
*iattr
)
366 struct inode
*inode
= dentry
->d_inode
;
369 WARN_ON_ONCE(inode
->i_op
->truncate
);
371 error
= inode_change_ok(inode
, iattr
);
375 if (iattr
->ia_valid
& ATTR_SIZE
)
376 truncate_setsize(inode
, iattr
->ia_size
);
377 setattr_copy(inode
, iattr
);
378 mark_inode_dirty(inode
);
381 EXPORT_SYMBOL(simple_setattr
);
383 int simple_readpage(struct file
*file
, struct page
*page
)
385 clear_highpage(page
);
386 flush_dcache_page(page
);
387 SetPageUptodate(page
);
392 int simple_write_begin(struct file
*file
, struct address_space
*mapping
,
393 loff_t pos
, unsigned len
, unsigned flags
,
394 struct page
**pagep
, void **fsdata
)
399 index
= pos
>> PAGE_CACHE_SHIFT
;
401 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
407 if (!PageUptodate(page
) && (len
!= PAGE_CACHE_SIZE
)) {
408 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
410 zero_user_segments(page
, 0, from
, from
+ len
, PAGE_CACHE_SIZE
);
416 * simple_write_end - .write_end helper for non-block-device FSes
417 * @available: See .write_end of address_space_operations
426 * simple_write_end does the minimum needed for updating a page after writing is
427 * done. It has the same API signature as the .write_end of
428 * address_space_operations vector. So it can just be set onto .write_end for
429 * FSes that don't need any other processing. i_mutex is assumed to be held.
430 * Block based filesystems should use generic_write_end().
431 * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
432 * is not called, so a filesystem that actually does store data in .write_inode
433 * should extend on what's done here with a call to mark_inode_dirty() in the
434 * case that i_size has changed.
436 int simple_write_end(struct file
*file
, struct address_space
*mapping
,
437 loff_t pos
, unsigned len
, unsigned copied
,
438 struct page
*page
, void *fsdata
)
440 struct inode
*inode
= page
->mapping
->host
;
441 loff_t last_pos
= pos
+ copied
;
443 /* zero the stale part of the page if we did a short copy */
445 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
447 zero_user(page
, from
+ copied
, len
- copied
);
450 if (!PageUptodate(page
))
451 SetPageUptodate(page
);
453 * No need to use i_size_read() here, the i_size
454 * cannot change under us because we hold the i_mutex.
456 if (last_pos
> inode
->i_size
)
457 i_size_write(inode
, last_pos
);
459 set_page_dirty(page
);
461 page_cache_release(page
);
467 * the inodes created here are not hashed. If you use iunique to generate
468 * unique inode values later for this filesystem, then you must take care
469 * to pass it an appropriate max_reserved value to avoid collisions.
471 int simple_fill_super(struct super_block
*s
, unsigned long magic
,
472 struct tree_descr
*files
)
476 struct dentry
*dentry
;
479 s
->s_blocksize
= PAGE_CACHE_SIZE
;
480 s
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
482 s
->s_op
= &simple_super_operations
;
485 inode
= new_inode(s
);
489 * because the root inode is 1, the files array must not contain an
493 inode
->i_mode
= S_IFDIR
| 0755;
494 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
495 inode
->i_op
= &simple_dir_inode_operations
;
496 inode
->i_fop
= &simple_dir_operations
;
498 root
= d_alloc_root(inode
);
503 for (i
= 0; !files
->name
|| files
->name
[0]; i
++, files
++) {
507 /* warn if it tries to conflict with the root inode */
508 if (unlikely(i
== 1))
509 printk(KERN_WARNING
"%s: %s passed in a files array"
510 "with an index of 1!\n", __func__
,
513 dentry
= d_alloc_name(root
, files
->name
);
516 inode
= new_inode(s
);
519 inode
->i_mode
= S_IFREG
| files
->mode
;
520 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
521 inode
->i_fop
= files
->ops
;
523 d_add(dentry
, inode
);
533 static DEFINE_SPINLOCK(pin_fs_lock
);
535 int simple_pin_fs(struct file_system_type
*type
, struct vfsmount
**mount
, int *count
)
537 struct vfsmount
*mnt
= NULL
;
538 spin_lock(&pin_fs_lock
);
539 if (unlikely(!*mount
)) {
540 spin_unlock(&pin_fs_lock
);
541 mnt
= vfs_kern_mount(type
, 0, type
->name
, NULL
);
544 spin_lock(&pin_fs_lock
);
550 spin_unlock(&pin_fs_lock
);
555 void simple_release_fs(struct vfsmount
**mount
, int *count
)
557 struct vfsmount
*mnt
;
558 spin_lock(&pin_fs_lock
);
562 spin_unlock(&pin_fs_lock
);
567 * simple_read_from_buffer - copy data from the buffer to user space
568 * @to: the user space buffer to read to
569 * @count: the maximum number of bytes to read
570 * @ppos: the current position in the buffer
571 * @from: the buffer to read from
572 * @available: the size of the buffer
574 * The simple_read_from_buffer() function reads up to @count bytes from the
575 * buffer @from at offset @ppos into the user space address starting at @to.
577 * On success, the number of bytes read is returned and the offset @ppos is
578 * advanced by this number, or negative value is returned on error.
580 ssize_t
simple_read_from_buffer(void __user
*to
, size_t count
, loff_t
*ppos
,
581 const void *from
, size_t available
)
588 if (pos
>= available
|| !count
)
590 if (count
> available
- pos
)
591 count
= available
- pos
;
592 ret
= copy_to_user(to
, from
+ pos
, count
);
601 * simple_write_to_buffer - copy data from user space to the buffer
602 * @to: the buffer to write to
603 * @available: the size of the buffer
604 * @ppos: the current position in the buffer
605 * @from: the user space buffer to read from
606 * @count: the maximum number of bytes to read
608 * The simple_write_to_buffer() function reads up to @count bytes from the user
609 * space address starting at @from into the buffer @to at offset @ppos.
611 * On success, the number of bytes written is returned and the offset @ppos is
612 * advanced by this number, or negative value is returned on error.
614 ssize_t
simple_write_to_buffer(void *to
, size_t available
, loff_t
*ppos
,
615 const void __user
*from
, size_t count
)
622 if (pos
>= available
|| !count
)
624 if (count
> available
- pos
)
625 count
= available
- pos
;
626 res
= copy_from_user(to
+ pos
, from
, count
);
635 * memory_read_from_buffer - copy data from the buffer
636 * @to: the kernel space buffer to read to
637 * @count: the maximum number of bytes to read
638 * @ppos: the current position in the buffer
639 * @from: the buffer to read from
640 * @available: the size of the buffer
642 * The memory_read_from_buffer() function reads up to @count bytes from the
643 * buffer @from at offset @ppos into the kernel space address starting at @to.
645 * On success, the number of bytes read is returned and the offset @ppos is
646 * advanced by this number, or negative value is returned on error.
648 ssize_t
memory_read_from_buffer(void *to
, size_t count
, loff_t
*ppos
,
649 const void *from
, size_t available
)
655 if (pos
>= available
)
657 if (count
> available
- pos
)
658 count
= available
- pos
;
659 memcpy(to
, from
+ pos
, count
);
666 * Transaction based IO.
667 * The file expects a single write which triggers the transaction, and then
668 * possibly a read which collects the result - which is stored in a
672 void simple_transaction_set(struct file
*file
, size_t n
)
674 struct simple_transaction_argresp
*ar
= file
->private_data
;
676 BUG_ON(n
> SIMPLE_TRANSACTION_LIMIT
);
679 * The barrier ensures that ar->size will really remain zero until
680 * ar->data is ready for reading.
686 char *simple_transaction_get(struct file
*file
, const char __user
*buf
, size_t size
)
688 struct simple_transaction_argresp
*ar
;
689 static DEFINE_SPINLOCK(simple_transaction_lock
);
691 if (size
> SIMPLE_TRANSACTION_LIMIT
- 1)
692 return ERR_PTR(-EFBIG
);
694 ar
= (struct simple_transaction_argresp
*)get_zeroed_page(GFP_KERNEL
);
696 return ERR_PTR(-ENOMEM
);
698 spin_lock(&simple_transaction_lock
);
700 /* only one write allowed per open */
701 if (file
->private_data
) {
702 spin_unlock(&simple_transaction_lock
);
703 free_page((unsigned long)ar
);
704 return ERR_PTR(-EBUSY
);
707 file
->private_data
= ar
;
709 spin_unlock(&simple_transaction_lock
);
711 if (copy_from_user(ar
->data
, buf
, size
))
712 return ERR_PTR(-EFAULT
);
717 ssize_t
simple_transaction_read(struct file
*file
, char __user
*buf
, size_t size
, loff_t
*pos
)
719 struct simple_transaction_argresp
*ar
= file
->private_data
;
723 return simple_read_from_buffer(buf
, size
, pos
, ar
->data
, ar
->size
);
726 int simple_transaction_release(struct inode
*inode
, struct file
*file
)
728 free_page((unsigned long)file
->private_data
);
732 /* Simple attribute files */
735 int (*get
)(void *, u64
*);
736 int (*set
)(void *, u64
);
737 char get_buf
[24]; /* enough to store a u64 and "\n\0" */
740 const char *fmt
; /* format for read operation */
741 struct mutex mutex
; /* protects access to these buffers */
744 /* simple_attr_open is called by an actual attribute open file operation
745 * to set the attribute specific access operations. */
746 int simple_attr_open(struct inode
*inode
, struct file
*file
,
747 int (*get
)(void *, u64
*), int (*set
)(void *, u64
),
750 struct simple_attr
*attr
;
752 attr
= kmalloc(sizeof(*attr
), GFP_KERNEL
);
758 attr
->data
= inode
->i_private
;
760 mutex_init(&attr
->mutex
);
762 file
->private_data
= attr
;
764 return nonseekable_open(inode
, file
);
767 int simple_attr_release(struct inode
*inode
, struct file
*file
)
769 kfree(file
->private_data
);
773 /* read from the buffer that is filled with the get function */
774 ssize_t
simple_attr_read(struct file
*file
, char __user
*buf
,
775 size_t len
, loff_t
*ppos
)
777 struct simple_attr
*attr
;
781 attr
= file
->private_data
;
786 ret
= mutex_lock_interruptible(&attr
->mutex
);
790 if (*ppos
) { /* continued read */
791 size
= strlen(attr
->get_buf
);
792 } else { /* first read */
794 ret
= attr
->get(attr
->data
, &val
);
798 size
= scnprintf(attr
->get_buf
, sizeof(attr
->get_buf
),
799 attr
->fmt
, (unsigned long long)val
);
802 ret
= simple_read_from_buffer(buf
, len
, ppos
, attr
->get_buf
, size
);
804 mutex_unlock(&attr
->mutex
);
808 /* interpret the buffer as a number to call the set function with */
809 ssize_t
simple_attr_write(struct file
*file
, const char __user
*buf
,
810 size_t len
, loff_t
*ppos
)
812 struct simple_attr
*attr
;
817 attr
= file
->private_data
;
821 ret
= mutex_lock_interruptible(&attr
->mutex
);
826 size
= min(sizeof(attr
->set_buf
) - 1, len
);
827 if (copy_from_user(attr
->set_buf
, buf
, size
))
830 attr
->set_buf
[size
] = '\0';
831 val
= simple_strtol(attr
->set_buf
, NULL
, 0);
832 ret
= attr
->set(attr
->data
, val
);
834 ret
= len
; /* on success, claim we got the whole input */
836 mutex_unlock(&attr
->mutex
);
841 * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
842 * @sb: filesystem to do the file handle conversion on
843 * @fid: file handle to convert
844 * @fh_len: length of the file handle in bytes
845 * @fh_type: type of file handle
846 * @get_inode: filesystem callback to retrieve inode
848 * This function decodes @fid as long as it has one of the well-known
849 * Linux filehandle types and calls @get_inode on it to retrieve the
850 * inode for the object specified in the file handle.
852 struct dentry
*generic_fh_to_dentry(struct super_block
*sb
, struct fid
*fid
,
853 int fh_len
, int fh_type
, struct inode
*(*get_inode
)
854 (struct super_block
*sb
, u64 ino
, u32 gen
))
856 struct inode
*inode
= NULL
;
862 case FILEID_INO32_GEN
:
863 case FILEID_INO32_GEN_PARENT
:
864 inode
= get_inode(sb
, fid
->i32
.ino
, fid
->i32
.gen
);
868 return d_obtain_alias(inode
);
870 EXPORT_SYMBOL_GPL(generic_fh_to_dentry
);
873 * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
874 * @sb: filesystem to do the file handle conversion on
875 * @fid: file handle to convert
876 * @fh_len: length of the file handle in bytes
877 * @fh_type: type of file handle
878 * @get_inode: filesystem callback to retrieve inode
880 * This function decodes @fid as long as it has one of the well-known
881 * Linux filehandle types and calls @get_inode on it to retrieve the
882 * inode for the _parent_ object specified in the file handle if it
883 * is specified in the file handle, or NULL otherwise.
885 struct dentry
*generic_fh_to_parent(struct super_block
*sb
, struct fid
*fid
,
886 int fh_len
, int fh_type
, struct inode
*(*get_inode
)
887 (struct super_block
*sb
, u64 ino
, u32 gen
))
889 struct inode
*inode
= NULL
;
895 case FILEID_INO32_GEN_PARENT
:
896 inode
= get_inode(sb
, fid
->i32
.parent_ino
,
897 (fh_len
> 3 ? fid
->i32
.parent_gen
: 0));
901 return d_obtain_alias(inode
);
903 EXPORT_SYMBOL_GPL(generic_fh_to_parent
);
906 * generic_file_fsync - generic fsync implementation for simple filesystems
907 * @file: file to synchronize
908 * @datasync: only synchronize essential metadata if true
910 * This is a generic implementation of the fsync method for simple
911 * filesystems which track all non-inode metadata in the buffers list
912 * hanging off the address_space structure.
914 int generic_file_fsync(struct file
*file
, int datasync
)
916 struct inode
*inode
= file
->f_mapping
->host
;
920 ret
= sync_mapping_buffers(inode
->i_mapping
);
921 if (!(inode
->i_state
& I_DIRTY
))
923 if (datasync
&& !(inode
->i_state
& I_DIRTY_DATASYNC
))
926 err
= sync_inode_metadata(inode
, 1);
931 EXPORT_SYMBOL(generic_file_fsync
);
934 * generic_check_addressable - Check addressability of file system
935 * @blocksize_bits: log of file system block size
936 * @num_blocks: number of blocks in file system
938 * Determine whether a file system with @num_blocks blocks (and a
939 * block size of 2**@blocksize_bits) is addressable by the sector_t
940 * and page cache of the system. Return 0 if so and -EFBIG otherwise.
942 int generic_check_addressable(unsigned blocksize_bits
, u64 num_blocks
)
944 u64 last_fs_block
= num_blocks
- 1;
946 last_fs_block
>> (PAGE_CACHE_SHIFT
- blocksize_bits
);
948 if (unlikely(num_blocks
== 0))
951 if ((blocksize_bits
< 9) || (blocksize_bits
> PAGE_CACHE_SHIFT
))
954 if ((last_fs_block
> (sector_t
)(~0ULL) >> (blocksize_bits
- 9)) ||
955 (last_fs_page
> (pgoff_t
)(~0ULL))) {
960 EXPORT_SYMBOL(generic_check_addressable
);
963 * No-op implementation of ->fsync for in-memory filesystems.
965 int noop_fsync(struct file
*file
, int datasync
)
970 EXPORT_SYMBOL(dcache_dir_close
);
971 EXPORT_SYMBOL(dcache_dir_lseek
);
972 EXPORT_SYMBOL(dcache_dir_open
);
973 EXPORT_SYMBOL(dcache_readdir
);
974 EXPORT_SYMBOL(generic_read_dir
);
975 EXPORT_SYMBOL(mount_pseudo
);
976 EXPORT_SYMBOL(simple_write_begin
);
977 EXPORT_SYMBOL(simple_write_end
);
978 EXPORT_SYMBOL(simple_dir_inode_operations
);
979 EXPORT_SYMBOL(simple_dir_operations
);
980 EXPORT_SYMBOL(simple_empty
);
981 EXPORT_SYMBOL(simple_fill_super
);
982 EXPORT_SYMBOL(simple_getattr
);
983 EXPORT_SYMBOL(simple_link
);
984 EXPORT_SYMBOL(simple_lookup
);
985 EXPORT_SYMBOL(simple_pin_fs
);
986 EXPORT_SYMBOL(simple_readpage
);
987 EXPORT_SYMBOL(simple_release_fs
);
988 EXPORT_SYMBOL(simple_rename
);
989 EXPORT_SYMBOL(simple_rmdir
);
990 EXPORT_SYMBOL(simple_statfs
);
991 EXPORT_SYMBOL(noop_fsync
);
992 EXPORT_SYMBOL(simple_unlink
);
993 EXPORT_SYMBOL(simple_read_from_buffer
);
994 EXPORT_SYMBOL(simple_write_to_buffer
);
995 EXPORT_SYMBOL(memory_read_from_buffer
);
996 EXPORT_SYMBOL(simple_transaction_set
);
997 EXPORT_SYMBOL(simple_transaction_get
);
998 EXPORT_SYMBOL(simple_transaction_read
);
999 EXPORT_SYMBOL(simple_transaction_release
);
1000 EXPORT_SYMBOL_GPL(simple_attr_open
);
1001 EXPORT_SYMBOL_GPL(simple_attr_release
);
1002 EXPORT_SYMBOL_GPL(simple_attr_read
);
1003 EXPORT_SYMBOL_GPL(simple_attr_write
);