4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * super.c contains code to handle: - mount structures
8 * - filesystem drivers list
10 * - umount system call
13 * GK 2/5/95 - Changed to support mounting the root fs via NFS
15 * Added kerneld support: Jacques Gelinas and Bjorn Ekwall
16 * Added change_root: Werner Almesberger & Hans Lermen, Feb '96
17 * Added options to /proc/mounts:
18 * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
19 * Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
20 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/smp_lock.h>
27 #include <linux/acct.h>
28 #include <linux/blkdev.h>
29 #include <linux/quotaops.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/security.h>
33 #include <linux/syscalls.h>
34 #include <linux/vfs.h>
35 #include <linux/writeback.h> /* for the emergency remount stuff */
36 #include <linux/idr.h>
37 #include <linux/kobject.h>
38 #include <linux/mutex.h>
39 #include <linux/file.h>
40 #include <linux/backing-dev.h>
41 #include <asm/uaccess.h>
45 LIST_HEAD(super_blocks
);
46 DEFINE_SPINLOCK(sb_lock
);
49 * alloc_super - create new superblock
50 * @type: filesystem type superblock should belong to
52 * Allocates and initializes a new &struct super_block. alloc_super()
53 * returns a pointer new superblock or %NULL if allocation had failed.
55 static struct super_block
*alloc_super(struct file_system_type
*type
)
57 struct super_block
*s
= kzalloc(sizeof(struct super_block
), GFP_USER
);
58 static const struct super_operations default_op
;
61 if (security_sb_alloc(s
)) {
66 INIT_LIST_HEAD(&s
->s_files
);
67 INIT_LIST_HEAD(&s
->s_instances
);
68 INIT_HLIST_HEAD(&s
->s_anon
);
69 INIT_LIST_HEAD(&s
->s_inodes
);
70 INIT_LIST_HEAD(&s
->s_dentry_lru
);
71 init_rwsem(&s
->s_umount
);
72 mutex_init(&s
->s_lock
);
73 lockdep_set_class(&s
->s_umount
, &type
->s_umount_key
);
75 * The locking rules for s_lock are up to the
76 * filesystem. For example ext3fs has different
77 * lock ordering than usbfs:
79 lockdep_set_class(&s
->s_lock
, &type
->s_lock_key
);
81 * sget() can have s_umount recursion.
83 * When it cannot find a suitable sb, it allocates a new
84 * one (this one), and tries again to find a suitable old
87 * In case that succeeds, it will acquire the s_umount
88 * lock of the old one. Since these are clearly distrinct
89 * locks, and this object isn't exposed yet, there's no
92 * Annotate this by putting this lock in a different
95 down_write_nested(&s
->s_umount
, SINGLE_DEPTH_NESTING
);
97 atomic_set(&s
->s_active
, 1);
98 mutex_init(&s
->s_vfs_rename_mutex
);
99 mutex_init(&s
->s_dquot
.dqio_mutex
);
100 mutex_init(&s
->s_dquot
.dqonoff_mutex
);
101 init_rwsem(&s
->s_dquot
.dqptr_sem
);
102 init_waitqueue_head(&s
->s_wait_unfrozen
);
103 s
->s_maxbytes
= MAX_NON_LFS
;
104 s
->dq_op
= sb_dquot_ops
;
105 s
->s_qcop
= sb_quotactl_ops
;
106 s
->s_op
= &default_op
;
107 s
->s_time_gran
= 1000000000;
114 * destroy_super - frees a superblock
115 * @s: superblock to free
117 * Frees a superblock.
119 static inline void destroy_super(struct super_block
*s
)
127 /* Superblock refcounting */
130 * Drop a superblock's refcount. The caller must hold sb_lock.
132 void __put_super(struct super_block
*sb
)
134 if (!--sb
->s_count
) {
135 list_del_init(&sb
->s_list
);
141 * put_super - drop a temporary reference to superblock
142 * @sb: superblock in question
144 * Drops a temporary reference, frees superblock if there's no
147 void put_super(struct super_block
*sb
)
151 spin_unlock(&sb_lock
);
156 * deactivate_locked_super - drop an active reference to superblock
157 * @s: superblock to deactivate
159 * Drops an active reference to superblock, converting it into a temprory
160 * one if there is no other active references left. In that case we
161 * tell fs driver to shut it down and drop the temporary reference we
164 * Caller holds exclusive lock on superblock; that lock is released.
166 void deactivate_locked_super(struct super_block
*s
)
168 struct file_system_type
*fs
= s
->s_type
;
169 if (atomic_dec_and_test(&s
->s_active
)) {
175 up_write(&s
->s_umount
);
179 EXPORT_SYMBOL(deactivate_locked_super
);
182 * deactivate_super - drop an active reference to superblock
183 * @s: superblock to deactivate
185 * Variant of deactivate_locked_super(), except that superblock is *not*
186 * locked by caller. If we are going to drop the final active reference,
187 * lock will be acquired prior to that.
189 void deactivate_super(struct super_block
*s
)
191 if (!atomic_add_unless(&s
->s_active
, -1, 1)) {
192 down_write(&s
->s_umount
);
193 deactivate_locked_super(s
);
197 EXPORT_SYMBOL(deactivate_super
);
200 * grab_super - acquire an active reference
201 * @s: reference we are trying to make active
203 * Tries to acquire an active reference. grab_super() is used when we
204 * had just found a superblock in super_blocks or fs_type->fs_supers
205 * and want to turn it into a full-blown active reference. grab_super()
206 * is called with sb_lock held and drops it. Returns 1 in case of
207 * success, 0 if we had failed (superblock contents was already dead or
208 * dying when grab_super() had been called).
210 static int grab_super(struct super_block
*s
) __releases(sb_lock
)
212 if (atomic_inc_not_zero(&s
->s_active
)) {
213 spin_unlock(&sb_lock
);
214 down_write(&s
->s_umount
);
217 /* it's going away */
219 spin_unlock(&sb_lock
);
220 /* wait for it to die */
221 down_write(&s
->s_umount
);
222 up_write(&s
->s_umount
);
228 * Superblock locking. We really ought to get rid of these two.
230 void lock_super(struct super_block
* sb
)
233 mutex_lock(&sb
->s_lock
);
236 void unlock_super(struct super_block
* sb
)
239 mutex_unlock(&sb
->s_lock
);
242 EXPORT_SYMBOL(lock_super
);
243 EXPORT_SYMBOL(unlock_super
);
246 * generic_shutdown_super - common helper for ->kill_sb()
247 * @sb: superblock to kill
249 * generic_shutdown_super() does all fs-independent work on superblock
250 * shutdown. Typical ->kill_sb() should pick all fs-specific objects
251 * that need destruction out of superblock, call generic_shutdown_super()
252 * and release aforementioned objects. Note: dentries and inodes _are_
253 * taken care of and do not need specific handling.
255 * Upon calling this function, the filesystem may no longer alter or
256 * rearrange the set of dentries belonging to this super_block, nor may it
257 * change the attachments of dentries to inodes.
259 void generic_shutdown_super(struct super_block
*sb
)
261 const struct super_operations
*sop
= sb
->s_op
;
265 shrink_dcache_for_umount(sb
);
268 sb
->s_flags
&= ~MS_ACTIVE
;
270 /* bad name - it should be evict_inodes() */
271 invalidate_inodes(sb
);
276 /* Forget any remaining inodes */
277 if (invalidate_inodes(sb
)) {
278 printk("VFS: Busy inodes after unmount of %s. "
279 "Self-destruct in 5 seconds. Have a nice day...\n",
285 /* should be initialized for __put_super_and_need_restart() */
286 list_del_init(&sb
->s_instances
);
287 spin_unlock(&sb_lock
);
288 up_write(&sb
->s_umount
);
291 EXPORT_SYMBOL(generic_shutdown_super
);
294 * sget - find or create a superblock
295 * @type: filesystem type superblock should belong to
296 * @test: comparison callback
297 * @set: setup callback
298 * @data: argument to each of them
300 struct super_block
*sget(struct file_system_type
*type
,
301 int (*test
)(struct super_block
*,void *),
302 int (*set
)(struct super_block
*,void *),
305 struct super_block
*s
= NULL
;
306 struct super_block
*old
;
312 list_for_each_entry(old
, &type
->fs_supers
, s_instances
) {
313 if (!test(old
, data
))
315 if (!grab_super(old
))
318 up_write(&s
->s_umount
);
325 spin_unlock(&sb_lock
);
326 s
= alloc_super(type
);
328 return ERR_PTR(-ENOMEM
);
334 spin_unlock(&sb_lock
);
335 up_write(&s
->s_umount
);
340 strlcpy(s
->s_id
, type
->name
, sizeof(s
->s_id
));
341 list_add_tail(&s
->s_list
, &super_blocks
);
342 list_add(&s
->s_instances
, &type
->fs_supers
);
343 spin_unlock(&sb_lock
);
344 get_filesystem(type
);
350 void drop_super(struct super_block
*sb
)
352 up_read(&sb
->s_umount
);
356 EXPORT_SYMBOL(drop_super
);
359 * sync_supers - helper for periodic superblock writeback
361 * Call the write_super method if present on all dirty superblocks in
362 * the system. This is for the periodic writeback used by most older
363 * filesystems. For data integrity superblock writeback use
364 * sync_filesystems() instead.
366 * Note: check the dirty flag before waiting, so we don't
367 * hold up the sync while mounting a device. (The newly
368 * mounted device won't need syncing.)
370 void sync_supers(void)
372 struct super_block
*sb
, *n
;
375 list_for_each_entry_safe(sb
, n
, &super_blocks
, s_list
) {
376 if (list_empty(&sb
->s_instances
))
378 if (sb
->s_op
->write_super
&& sb
->s_dirt
) {
380 spin_unlock(&sb_lock
);
382 down_read(&sb
->s_umount
);
383 if (sb
->s_root
&& sb
->s_dirt
)
384 sb
->s_op
->write_super(sb
);
385 up_read(&sb
->s_umount
);
391 spin_unlock(&sb_lock
);
395 * iterate_supers - call function for all active superblocks
396 * @f: function to call
397 * @arg: argument to pass to it
399 * Scans the superblock list and calls given function, passing it
400 * locked superblock and given argument.
402 void iterate_supers(void (*f
)(struct super_block
*, void *), void *arg
)
404 struct super_block
*sb
, *n
;
407 list_for_each_entry_safe(sb
, n
, &super_blocks
, s_list
) {
408 if (list_empty(&sb
->s_instances
))
411 spin_unlock(&sb_lock
);
413 down_read(&sb
->s_umount
);
416 up_read(&sb
->s_umount
);
421 spin_unlock(&sb_lock
);
425 * get_super - get the superblock of a device
426 * @bdev: device to get the superblock for
428 * Scans the superblock list and finds the superblock of the file system
429 * mounted on the device given. %NULL is returned if no match is found.
432 struct super_block
*get_super(struct block_device
*bdev
)
434 struct super_block
*sb
;
441 list_for_each_entry(sb
, &super_blocks
, s_list
) {
442 if (list_empty(&sb
->s_instances
))
444 if (sb
->s_bdev
== bdev
) {
446 spin_unlock(&sb_lock
);
447 down_read(&sb
->s_umount
);
451 up_read(&sb
->s_umount
);
452 /* nope, got unmounted */
458 spin_unlock(&sb_lock
);
462 EXPORT_SYMBOL(get_super
);
465 * get_active_super - get an active reference to the superblock of a device
466 * @bdev: device to get the superblock for
468 * Scans the superblock list and finds the superblock of the file system
469 * mounted on the device given. Returns the superblock with an active
470 * reference and s_umount held exclusively or %NULL if none was found.
472 struct super_block
*get_active_super(struct block_device
*bdev
)
474 struct super_block
*sb
;
481 list_for_each_entry(sb
, &super_blocks
, s_list
) {
482 if (list_empty(&sb
->s_instances
))
484 if (sb
->s_bdev
== bdev
) {
485 if (grab_super(sb
)) /* drops sb_lock */
491 spin_unlock(&sb_lock
);
495 struct super_block
*user_get_super(dev_t dev
)
497 struct super_block
*sb
;
501 list_for_each_entry(sb
, &super_blocks
, s_list
) {
502 if (list_empty(&sb
->s_instances
))
504 if (sb
->s_dev
== dev
) {
506 spin_unlock(&sb_lock
);
507 down_read(&sb
->s_umount
);
511 up_read(&sb
->s_umount
);
512 /* nope, got unmounted */
518 spin_unlock(&sb_lock
);
522 SYSCALL_DEFINE2(ustat
, unsigned, dev
, struct ustat __user
*, ubuf
)
524 struct super_block
*s
;
529 s
= user_get_super(new_decode_dev(dev
));
532 err
= vfs_statfs(s
->s_root
, &sbuf
);
537 memset(&tmp
,0,sizeof(struct ustat
));
538 tmp
.f_tfree
= sbuf
.f_bfree
;
539 tmp
.f_tinode
= sbuf
.f_ffree
;
541 err
= copy_to_user(ubuf
,&tmp
,sizeof(struct ustat
)) ? -EFAULT
: 0;
547 * do_remount_sb - asks filesystem to change mount options.
548 * @sb: superblock in question
549 * @flags: numeric part of options
550 * @data: the rest of options
551 * @force: whether or not to force the change
553 * Alters the mount options of a mounted file system.
555 int do_remount_sb(struct super_block
*sb
, int flags
, void *data
, int force
)
558 int remount_rw
, remount_ro
;
560 if (sb
->s_frozen
!= SB_UNFROZEN
)
564 if (!(flags
& MS_RDONLY
) && bdev_read_only(sb
->s_bdev
))
568 if (flags
& MS_RDONLY
)
570 shrink_dcache_sb(sb
);
573 remount_ro
= (flags
& MS_RDONLY
) && !(sb
->s_flags
& MS_RDONLY
);
574 remount_rw
= !(flags
& MS_RDONLY
) && (sb
->s_flags
& MS_RDONLY
);
576 /* If we are remounting RDONLY and current sb is read/write,
577 make sure there are no rw files opened */
581 else if (!fs_may_remount_ro(sb
))
583 retval
= vfs_dq_off(sb
, 1);
584 if (retval
< 0 && retval
!= -ENOSYS
)
588 if (sb
->s_op
->remount_fs
) {
589 retval
= sb
->s_op
->remount_fs(sb
, &flags
, data
);
593 sb
->s_flags
= (sb
->s_flags
& ~MS_RMT_MASK
) | (flags
& MS_RMT_MASK
);
595 vfs_dq_quota_on_remount(sb
);
597 * Some filesystems modify their metadata via some other path than the
598 * bdev buffer cache (eg. use a private mapping, or directories in
599 * pagecache, etc). Also file data modifications go via their own
600 * mappings. So If we try to mount readonly then copy the filesystem
601 * from bdev, we could get stale data, so invalidate it to give a best
602 * effort at coherency.
604 if (remount_ro
&& sb
->s_bdev
)
605 invalidate_bdev(sb
->s_bdev
);
609 static void do_emergency_remount(struct work_struct
*work
)
611 struct super_block
*sb
, *n
;
614 list_for_each_entry_safe(sb
, n
, &super_blocks
, s_list
) {
615 if (list_empty(&sb
->s_instances
))
618 spin_unlock(&sb_lock
);
619 down_write(&sb
->s_umount
);
620 if (sb
->s_root
&& sb
->s_bdev
&& !(sb
->s_flags
& MS_RDONLY
)) {
622 * What lock protects sb->s_flags??
624 do_remount_sb(sb
, MS_RDONLY
, NULL
, 1);
626 up_write(&sb
->s_umount
);
630 spin_unlock(&sb_lock
);
632 printk("Emergency Remount complete\n");
635 void emergency_remount(void)
637 struct work_struct
*work
;
639 work
= kmalloc(sizeof(*work
), GFP_ATOMIC
);
641 INIT_WORK(work
, do_emergency_remount
);
647 * Unnamed block devices are dummy devices used by virtual
648 * filesystems which don't use real block-devices. -- jrs
651 static DEFINE_IDA(unnamed_dev_ida
);
652 static DEFINE_SPINLOCK(unnamed_dev_lock
);/* protects the above */
653 static int unnamed_dev_start
= 0; /* don't bother trying below it */
655 int set_anon_super(struct super_block
*s
, void *data
)
661 if (ida_pre_get(&unnamed_dev_ida
, GFP_ATOMIC
) == 0)
663 spin_lock(&unnamed_dev_lock
);
664 error
= ida_get_new_above(&unnamed_dev_ida
, unnamed_dev_start
, &dev
);
666 unnamed_dev_start
= dev
+ 1;
667 spin_unlock(&unnamed_dev_lock
);
668 if (error
== -EAGAIN
)
669 /* We raced and lost with another CPU. */
674 if ((dev
& MAX_ID_MASK
) == (1 << MINORBITS
)) {
675 spin_lock(&unnamed_dev_lock
);
676 ida_remove(&unnamed_dev_ida
, dev
);
677 if (unnamed_dev_start
> dev
)
678 unnamed_dev_start
= dev
;
679 spin_unlock(&unnamed_dev_lock
);
682 s
->s_dev
= MKDEV(0, dev
& MINORMASK
);
683 s
->s_bdi
= &noop_backing_dev_info
;
687 EXPORT_SYMBOL(set_anon_super
);
689 void kill_anon_super(struct super_block
*sb
)
691 int slot
= MINOR(sb
->s_dev
);
693 generic_shutdown_super(sb
);
694 spin_lock(&unnamed_dev_lock
);
695 ida_remove(&unnamed_dev_ida
, slot
);
696 if (slot
< unnamed_dev_start
)
697 unnamed_dev_start
= slot
;
698 spin_unlock(&unnamed_dev_lock
);
701 EXPORT_SYMBOL(kill_anon_super
);
703 void kill_litter_super(struct super_block
*sb
)
706 d_genocide(sb
->s_root
);
710 EXPORT_SYMBOL(kill_litter_super
);
712 static int ns_test_super(struct super_block
*sb
, void *data
)
714 return sb
->s_fs_info
== data
;
717 static int ns_set_super(struct super_block
*sb
, void *data
)
719 sb
->s_fs_info
= data
;
720 return set_anon_super(sb
, NULL
);
723 int get_sb_ns(struct file_system_type
*fs_type
, int flags
, void *data
,
724 int (*fill_super
)(struct super_block
*, void *, int),
725 struct vfsmount
*mnt
)
727 struct super_block
*sb
;
729 sb
= sget(fs_type
, ns_test_super
, ns_set_super
, data
);
736 err
= fill_super(sb
, data
, flags
& MS_SILENT
? 1 : 0);
738 deactivate_locked_super(sb
);
742 sb
->s_flags
|= MS_ACTIVE
;
745 simple_set_mnt(mnt
, sb
);
749 EXPORT_SYMBOL(get_sb_ns
);
752 static int set_bdev_super(struct super_block
*s
, void *data
)
755 s
->s_dev
= s
->s_bdev
->bd_dev
;
758 * We set the bdi here to the queue backing, file systems can
759 * overwrite this in ->fill_super()
761 s
->s_bdi
= &bdev_get_queue(s
->s_bdev
)->backing_dev_info
;
765 static int test_bdev_super(struct super_block
*s
, void *data
)
767 return (void *)s
->s_bdev
== data
;
770 int get_sb_bdev(struct file_system_type
*fs_type
,
771 int flags
, const char *dev_name
, void *data
,
772 int (*fill_super
)(struct super_block
*, void *, int),
773 struct vfsmount
*mnt
)
775 struct block_device
*bdev
;
776 struct super_block
*s
;
777 fmode_t mode
= FMODE_READ
;
780 if (!(flags
& MS_RDONLY
))
783 bdev
= open_bdev_exclusive(dev_name
, mode
, fs_type
);
785 return PTR_ERR(bdev
);
788 * once the super is inserted into the list by sget, s_umount
789 * will protect the lockfs code from trying to start a snapshot
790 * while we are mounting
792 mutex_lock(&bdev
->bd_fsfreeze_mutex
);
793 if (bdev
->bd_fsfreeze_count
> 0) {
794 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
798 s
= sget(fs_type
, test_bdev_super
, set_bdev_super
, bdev
);
799 mutex_unlock(&bdev
->bd_fsfreeze_mutex
);
804 if ((flags
^ s
->s_flags
) & MS_RDONLY
) {
805 deactivate_locked_super(s
);
810 close_bdev_exclusive(bdev
, mode
);
812 char b
[BDEVNAME_SIZE
];
816 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
817 sb_set_blocksize(s
, block_size(bdev
));
818 error
= fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0);
820 deactivate_locked_super(s
);
824 s
->s_flags
|= MS_ACTIVE
;
828 simple_set_mnt(mnt
, s
);
834 close_bdev_exclusive(bdev
, mode
);
839 EXPORT_SYMBOL(get_sb_bdev
);
841 void kill_block_super(struct super_block
*sb
)
843 struct block_device
*bdev
= sb
->s_bdev
;
844 fmode_t mode
= sb
->s_mode
;
846 bdev
->bd_super
= NULL
;
847 generic_shutdown_super(sb
);
849 close_bdev_exclusive(bdev
, mode
);
852 EXPORT_SYMBOL(kill_block_super
);
855 int get_sb_nodev(struct file_system_type
*fs_type
,
856 int flags
, void *data
,
857 int (*fill_super
)(struct super_block
*, void *, int),
858 struct vfsmount
*mnt
)
861 struct super_block
*s
= sget(fs_type
, NULL
, set_anon_super
, NULL
);
868 error
= fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0);
870 deactivate_locked_super(s
);
873 s
->s_flags
|= MS_ACTIVE
;
874 simple_set_mnt(mnt
, s
);
878 EXPORT_SYMBOL(get_sb_nodev
);
880 static int compare_single(struct super_block
*s
, void *p
)
885 int get_sb_single(struct file_system_type
*fs_type
,
886 int flags
, void *data
,
887 int (*fill_super
)(struct super_block
*, void *, int),
888 struct vfsmount
*mnt
)
890 struct super_block
*s
;
893 s
= sget(fs_type
, compare_single
, set_anon_super
, NULL
);
898 error
= fill_super(s
, data
, flags
& MS_SILENT
? 1 : 0);
900 deactivate_locked_super(s
);
903 s
->s_flags
|= MS_ACTIVE
;
905 do_remount_sb(s
, flags
, data
, 0);
907 simple_set_mnt(mnt
, s
);
911 EXPORT_SYMBOL(get_sb_single
);
914 vfs_kern_mount(struct file_system_type
*type
, int flags
, const char *name
, void *data
)
916 struct vfsmount
*mnt
;
917 char *secdata
= NULL
;
921 return ERR_PTR(-ENODEV
);
924 mnt
= alloc_vfsmnt(name
);
928 if (flags
& MS_KERNMOUNT
)
929 mnt
->mnt_flags
= MNT_INTERNAL
;
931 if (data
&& !(type
->fs_flags
& FS_BINARY_MOUNTDATA
)) {
932 secdata
= alloc_secdata();
936 error
= security_sb_copy_data(data
, secdata
);
938 goto out_free_secdata
;
941 error
= type
->get_sb(type
, flags
, name
, data
, mnt
);
943 goto out_free_secdata
;
944 BUG_ON(!mnt
->mnt_sb
);
945 WARN_ON(!mnt
->mnt_sb
->s_bdi
);
947 error
= security_sb_kern_mount(mnt
->mnt_sb
, flags
, secdata
);
952 * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE
953 * but s_maxbytes was an unsigned long long for many releases. Throw
954 * this warning for a little while to try and catch filesystems that
955 * violate this rule. This warning should be either removed or
956 * converted to a BUG() in 2.6.34.
958 WARN((mnt
->mnt_sb
->s_maxbytes
< 0), "%s set sb->s_maxbytes to "
959 "negative value (%lld)\n", type
->name
, mnt
->mnt_sb
->s_maxbytes
);
961 mnt
->mnt_mountpoint
= mnt
->mnt_root
;
962 mnt
->mnt_parent
= mnt
;
963 up_write(&mnt
->mnt_sb
->s_umount
);
964 free_secdata(secdata
);
968 deactivate_locked_super(mnt
->mnt_sb
);
970 free_secdata(secdata
);
974 return ERR_PTR(error
);
977 EXPORT_SYMBOL_GPL(vfs_kern_mount
);
979 static struct vfsmount
*fs_set_subtype(struct vfsmount
*mnt
, const char *fstype
)
982 const char *subtype
= strchr(fstype
, '.');
991 mnt
->mnt_sb
->s_subtype
= kstrdup(subtype
, GFP_KERNEL
);
993 if (!mnt
->mnt_sb
->s_subtype
)
1003 do_kern_mount(const char *fstype
, int flags
, const char *name
, void *data
)
1005 struct file_system_type
*type
= get_fs_type(fstype
);
1006 struct vfsmount
*mnt
;
1008 return ERR_PTR(-ENODEV
);
1009 mnt
= vfs_kern_mount(type
, flags
, name
, data
);
1010 if (!IS_ERR(mnt
) && (type
->fs_flags
& FS_HAS_SUBTYPE
) &&
1011 !mnt
->mnt_sb
->s_subtype
)
1012 mnt
= fs_set_subtype(mnt
, fstype
);
1013 put_filesystem(type
);
1016 EXPORT_SYMBOL_GPL(do_kern_mount
);
1018 struct vfsmount
*kern_mount_data(struct file_system_type
*type
, void *data
)
1020 return vfs_kern_mount(type
, MS_KERNMOUNT
, type
->name
, data
);
1023 EXPORT_SYMBOL_GPL(kern_mount_data
);