diff options
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/quota/quota.c | 31 | ||||
| -rw-r--r-- | fs/super.c | 51 | ||||
| -rw-r--r-- | include/linux/fs.h | 4 |
4 files changed, 29 insertions, 59 deletions
diff --git a/fs/internal.h b/fs/internal.h index a7cd0f64faa4..47be21dfeebe 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -114,7 +114,9 @@ extern struct file *alloc_empty_file_noaccount(int, const struct cred *); */ extern int reconfigure_super(struct fs_context *); extern bool trylock_super(struct super_block *sb); +struct super_block *__get_super(struct block_device *bdev, bool excl); extern struct super_block *user_get_super(dev_t); +void put_super(struct super_block *sb); extern bool mount_capable(struct fs_context *); /* diff --git a/fs/quota/quota.c b/fs/quota/quota.c index 9af95c7a0bbe..f3d32b0d9008 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -20,6 +20,7 @@ #include <linux/writeback.h> #include <linux/nospec.h> #include "compat.h" +#include "../internal.h" static int check_quotactl_permission(struct super_block *sb, int type, int cmd, qid_t id) @@ -868,6 +869,7 @@ static struct super_block *quotactl_block(const char __user *special, int cmd) struct block_device *bdev; struct super_block *sb; struct filename *tmp = getname(special); + bool excl = false, thawed = false; if (IS_ERR(tmp)) return ERR_CAST(tmp); @@ -875,17 +877,32 @@ static struct super_block *quotactl_block(const char __user *special, int cmd) putname(tmp); if (IS_ERR(bdev)) return ERR_CAST(bdev); - if (quotactl_cmd_onoff(cmd)) - sb = get_super_exclusive_thawed(bdev); - else if (quotactl_cmd_write(cmd)) - sb = get_super_thawed(bdev); - else - sb = get_super(bdev); + + if (quotactl_cmd_onoff(cmd)) { + excl = true; + thawed = true; + } else if (quotactl_cmd_write(cmd)) { + thawed = true; + } + +retry: + sb = __get_super(bdev, excl); + if (thawed && sb && sb->s_writers.frozen != SB_UNFROZEN) { + if (excl) + up_write(&sb->s_umount); + else + up_read(&sb->s_umount); + wait_event(sb->s_writers.wait_unfrozen, + sb->s_writers.frozen == SB_UNFROZEN); + put_super(sb); + goto retry; + } + bdput(bdev); if (!sb) return ERR_PTR(-ENODEV); - return sb; + #else return ERR_PTR(-ENODEV); #endif diff --git a/fs/super.c b/fs/super.c index 98bb0629ee10..343e5c1e538d 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 +740,7 @@ 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) +struct super_block *__get_super(struct block_device *bdev, bool excl) { struct super_block *sb; @@ -789,53 +789,6 @@ struct super_block *get_super(struct block_device *bdev) } 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 diff --git a/include/linux/fs.h b/include/linux/fs.h index 8667d0cdc71e..a61df0dd4f19 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1409,7 +1409,7 @@ enum { struct sb_writers { int frozen; /* Is sb frozen? */ - wait_queue_head_t wait_unfrozen; /* for get_super_thawed() */ + wait_queue_head_t wait_unfrozen; /* wait for thaw */ struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; }; @@ -3132,8 +3132,6 @@ extern struct file_system_type *get_filesystem(struct file_system_type *fs); extern void put_filesystem(struct file_system_type *fs); extern struct file_system_type *get_fs_type(const char *name); extern struct super_block *get_super(struct block_device *); -extern struct super_block *get_super_thawed(struct block_device *); -extern struct super_block *get_super_exclusive_thawed(struct block_device *bdev); extern struct super_block *get_active_super(struct block_device *bdev); extern void drop_super(struct super_block *sb); extern void drop_super_exclusive(struct super_block *sb); |