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| author | Al Viro <viro@zeniv.linux.org.uk> | 2011-06-04 02:16:57 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-20 07:43:04 +0200 |
| commit | 43e15cdbefea4ce6d68113de98d4f61c0cf45687 (patch) | |
| tree | 75676aae179fc56bbb9d861c0ab656a9edaa7ca4 | |
| parent | fs: add a DCACHE_NEED_LOOKUP flag for d_flags (diff) | |
| download | linux-43e15cdbefea4ce6d68113de98d4f61c0cf45687.tar.xz linux-43e15cdbefea4ce6d68113de98d4f61c0cf45687.zip | |
new helper: iterate_supers_type()
Call the given function for all superblocks of given type. Function
gets a superblock (with s_umount locked shared) and (void *) argument
supplied by caller of iterator.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/super.c | 36 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
2 files changed, 38 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index ab3d672db0de..444da9579068 100644 --- a/fs/super.c +++ b/fs/super.c @@ -452,6 +452,42 @@ void iterate_supers(void (*f)(struct super_block *, void *), void *arg) } /** + * iterate_supers_type - call function for superblocks of given type + * @type: fs type + * @f: function to call + * @arg: argument to pass to it + * + * Scans the superblock list and calls given function, passing it + * locked superblock and given argument. + */ +void iterate_supers_type(struct file_system_type *type, + void (*f)(struct super_block *, void *), void *arg) +{ + struct super_block *sb, *p = NULL; + + spin_lock(&sb_lock); + list_for_each_entry(sb, &type->fs_supers, s_instances) { + sb->s_count++; + spin_unlock(&sb_lock); + + down_read(&sb->s_umount); + if (sb->s_root) + f(sb, arg); + up_read(&sb->s_umount); + + spin_lock(&sb_lock); + if (p) + __put_super(p); + p = sb; + } + if (p) + __put_super(p); + spin_unlock(&sb_lock); +} + +EXPORT_SYMBOL(iterate_supers_type); + +/** * get_super - get the superblock of a device * @bdev: device to get the superblock for * diff --git a/include/linux/fs.h b/include/linux/fs.h index b5b979247863..a8735e7e1b35 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2432,6 +2432,8 @@ extern struct super_block *get_active_super(struct block_device *bdev); extern struct super_block *user_get_super(dev_t); extern void drop_super(struct super_block *sb); extern void iterate_supers(void (*)(struct super_block *, void *), void *); +extern void iterate_supers_type(struct file_system_type *, + void (*)(struct super_block *, void *), void *); extern int dcache_dir_open(struct inode *, struct file *); extern int dcache_dir_close(struct inode *, struct file *); |