diff options
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 93 |
1 files changed, 20 insertions, 73 deletions
diff --git a/fs/super.c b/fs/super.c index 98bb0629ee10..2c6cdea2ab2d 100644 --- a/fs/super.c +++ b/fs/super.c @@ -307,7 +307,7 @@ static void __put_super(struct super_block *s) * Drops a temporary reference, frees superblock if there's no * references left. */ -static void put_super(struct super_block *sb) +void put_super(struct super_block *sb) { spin_lock(&sb_lock); __put_super(sb); @@ -740,7 +740,14 @@ void iterate_supers_type(struct file_system_type *type, EXPORT_SYMBOL(iterate_supers_type); -static struct super_block *__get_super(struct block_device *bdev, bool excl) +/** + * get_super - get the superblock of a device + * @bdev: device to get the superblock for + * + * Scans the superblock list and finds the superblock of the file system + * mounted on the device given. %NULL is returned if no match is found. + */ +struct super_block *get_super(struct block_device *bdev) { struct super_block *sb; @@ -755,17 +762,11 @@ rescan: if (sb->s_bdev == bdev) { sb->s_count++; spin_unlock(&sb_lock); - if (!excl) - down_read(&sb->s_umount); - else - down_write(&sb->s_umount); + down_read(&sb->s_umount); /* still alive? */ if (sb->s_root && (sb->s_flags & SB_BORN)) return sb; - if (!excl) - up_read(&sb->s_umount); - else - up_write(&sb->s_umount); + up_read(&sb->s_umount); /* nope, got unmounted */ spin_lock(&sb_lock); __put_super(sb); @@ -777,66 +778,6 @@ rescan: } /** - * get_super - get the superblock of a device - * @bdev: device to get the superblock for - * - * Scans the superblock list and finds the superblock of the file system - * mounted on the device given. %NULL is returned if no match is found. - */ -struct super_block *get_super(struct block_device *bdev) -{ - return __get_super(bdev, false); -} -EXPORT_SYMBOL(get_super); - -static struct super_block *__get_super_thawed(struct block_device *bdev, - bool excl) -{ - while (1) { - struct super_block *s = __get_super(bdev, excl); - if (!s || s->s_writers.frozen == SB_UNFROZEN) - return s; - if (!excl) - up_read(&s->s_umount); - else - up_write(&s->s_umount); - wait_event(s->s_writers.wait_unfrozen, - s->s_writers.frozen == SB_UNFROZEN); - put_super(s); - } -} - -/** - * get_super_thawed - get thawed superblock of a device - * @bdev: device to get the superblock for - * - * Scans the superblock list and finds the superblock of the file system - * mounted on the device. The superblock is returned once it is thawed - * (or immediately if it was not frozen). %NULL is returned if no match - * is found. - */ -struct super_block *get_super_thawed(struct block_device *bdev) -{ - return __get_super_thawed(bdev, false); -} -EXPORT_SYMBOL(get_super_thawed); - -/** - * get_super_exclusive_thawed - get thawed superblock of a device - * @bdev: device to get the superblock for - * - * Scans the superblock list and finds the superblock of the file system - * mounted on the device. The superblock is returned once it is thawed - * (or immediately if it was not frozen) and s_umount semaphore is held - * in exclusive mode. %NULL is returned if no match is found. - */ -struct super_block *get_super_exclusive_thawed(struct block_device *bdev) -{ - return __get_super_thawed(bdev, true); -} -EXPORT_SYMBOL(get_super_exclusive_thawed); - -/** * get_active_super - get an active reference to the superblock of a device * @bdev: device to get the superblock for * @@ -867,7 +808,7 @@ restart: return NULL; } -struct super_block *user_get_super(dev_t dev) +struct super_block *user_get_super(dev_t dev, bool excl) { struct super_block *sb; @@ -879,11 +820,17 @@ rescan: if (sb->s_dev == dev) { sb->s_count++; spin_unlock(&sb_lock); - down_read(&sb->s_umount); + if (excl) + down_write(&sb->s_umount); + else + down_read(&sb->s_umount); /* still alive? */ if (sb->s_root && (sb->s_flags & SB_BORN)) return sb; - up_read(&sb->s_umount); + if (excl) + up_write(&sb->s_umount); + else + up_read(&sb->s_umount); /* nope, got unmounted */ spin_lock(&sb_lock); __put_super(sb); |