Commit 040f04bd authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe

fs: simplify freeze_bdev/thaw_bdev

Store the frozen superblock in struct block_device to avoid the awkward
interface that can return a sb only used a cookie, an ERR_PTR or NULL.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com>		[f2fs]
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 60b49885
...@@ -96,11 +96,6 @@ struct mapped_device { ...@@ -96,11 +96,6 @@ struct mapped_device {
*/ */
struct workqueue_struct *wq; struct workqueue_struct *wq;
/*
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
/* forced geometry settings */ /* forced geometry settings */
struct hd_geometry geometry; struct hd_geometry geometry;
......
...@@ -2392,27 +2392,19 @@ static int lock_fs(struct mapped_device *md) ...@@ -2392,27 +2392,19 @@ static int lock_fs(struct mapped_device *md)
{ {
int r; int r;
WARN_ON(md->frozen_sb); WARN_ON(test_bit(DMF_FROZEN, &md->flags));
md->frozen_sb = freeze_bdev(md->bdev); r = freeze_bdev(md->bdev);
if (IS_ERR(md->frozen_sb)) { if (!r)
r = PTR_ERR(md->frozen_sb); set_bit(DMF_FROZEN, &md->flags);
md->frozen_sb = NULL; return r;
return r;
}
set_bit(DMF_FROZEN, &md->flags);
return 0;
} }
static void unlock_fs(struct mapped_device *md) static void unlock_fs(struct mapped_device *md)
{ {
if (!test_bit(DMF_FROZEN, &md->flags)) if (!test_bit(DMF_FROZEN, &md->flags))
return; return;
thaw_bdev(md->bdev);
thaw_bdev(md->bdev, md->frozen_sb);
md->frozen_sb = NULL;
clear_bit(DMF_FROZEN, &md->flags); clear_bit(DMF_FROZEN, &md->flags);
} }
......
...@@ -548,55 +548,47 @@ EXPORT_SYMBOL(fsync_bdev); ...@@ -548,55 +548,47 @@ EXPORT_SYMBOL(fsync_bdev);
* count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
* actually. * actually.
*/ */
struct super_block *freeze_bdev(struct block_device *bdev) int freeze_bdev(struct block_device *bdev)
{ {
struct super_block *sb; struct super_block *sb;
int error = 0; int error = 0;
mutex_lock(&bdev->bd_fsfreeze_mutex); mutex_lock(&bdev->bd_fsfreeze_mutex);
if (++bdev->bd_fsfreeze_count > 1) { if (++bdev->bd_fsfreeze_count > 1)
/* goto done;
* We don't even need to grab a reference - the first call
* to freeze_bdev grab an active reference and only the last
* thaw_bdev drops it.
*/
sb = get_super(bdev);
if (sb)
drop_super(sb);
mutex_unlock(&bdev->bd_fsfreeze_mutex);
return sb;
}
sb = get_active_super(bdev); sb = get_active_super(bdev);
if (!sb) if (!sb)
goto out; goto sync;
if (sb->s_op->freeze_super) if (sb->s_op->freeze_super)
error = sb->s_op->freeze_super(sb); error = sb->s_op->freeze_super(sb);
else else
error = freeze_super(sb); error = freeze_super(sb);
deactivate_super(sb);
if (error) { if (error) {
deactivate_super(sb);
bdev->bd_fsfreeze_count--; bdev->bd_fsfreeze_count--;
mutex_unlock(&bdev->bd_fsfreeze_mutex); goto done;
return ERR_PTR(error);
} }
deactivate_super(sb); bdev->bd_fsfreeze_sb = sb;
out:
sync:
sync_blockdev(bdev); sync_blockdev(bdev);
done:
mutex_unlock(&bdev->bd_fsfreeze_mutex); mutex_unlock(&bdev->bd_fsfreeze_mutex);
return sb; /* thaw_bdev releases s->s_umount */ return error;
} }
EXPORT_SYMBOL(freeze_bdev); EXPORT_SYMBOL(freeze_bdev);
/** /**
* thaw_bdev -- unlock filesystem * thaw_bdev -- unlock filesystem
* @bdev: blockdevice to unlock * @bdev: blockdevice to unlock
* @sb: associated superblock
* *
* Unlocks the filesystem and marks it writeable again after freeze_bdev(). * Unlocks the filesystem and marks it writeable again after freeze_bdev().
*/ */
int thaw_bdev(struct block_device *bdev, struct super_block *sb) int thaw_bdev(struct block_device *bdev)
{ {
struct super_block *sb;
int error = -EINVAL; int error = -EINVAL;
mutex_lock(&bdev->bd_fsfreeze_mutex); mutex_lock(&bdev->bd_fsfreeze_mutex);
...@@ -607,6 +599,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) ...@@ -607,6 +599,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
if (--bdev->bd_fsfreeze_count > 0) if (--bdev->bd_fsfreeze_count > 0)
goto out; goto out;
sb = bdev->bd_fsfreeze_sb;
if (!sb) if (!sb)
goto out; goto out;
......
...@@ -523,7 +523,7 @@ static int osync_buffers_list(spinlock_t *lock, struct list_head *list) ...@@ -523,7 +523,7 @@ static int osync_buffers_list(spinlock_t *lock, struct list_head *list)
void emergency_thaw_bdev(struct super_block *sb) void emergency_thaw_bdev(struct super_block *sb)
{ {
while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb)) while (sb->s_bdev && !thaw_bdev(sb->s_bdev))
printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev); printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev);
} }
......
...@@ -624,7 +624,7 @@ static int ext4_shutdown(struct super_block *sb, unsigned long arg) ...@@ -624,7 +624,7 @@ static int ext4_shutdown(struct super_block *sb, unsigned long arg)
case EXT4_GOING_FLAGS_DEFAULT: case EXT4_GOING_FLAGS_DEFAULT:
freeze_bdev(sb->s_bdev); freeze_bdev(sb->s_bdev);
set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags); set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
thaw_bdev(sb->s_bdev, sb); thaw_bdev(sb->s_bdev);
break; break;
case EXT4_GOING_FLAGS_LOGFLUSH: case EXT4_GOING_FLAGS_LOGFLUSH:
set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags); set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
......
...@@ -2230,16 +2230,12 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg) ...@@ -2230,16 +2230,12 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
switch (in) { switch (in) {
case F2FS_GOING_DOWN_FULLSYNC: case F2FS_GOING_DOWN_FULLSYNC:
sb = freeze_bdev(sb->s_bdev); ret = freeze_bdev(sb->s_bdev);
if (IS_ERR(sb)) { if (ret)
ret = PTR_ERR(sb);
goto out; goto out;
} f2fs_stop_checkpoint(sbi, false);
if (sb) { set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
f2fs_stop_checkpoint(sbi, false); thaw_bdev(sb->s_bdev);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
thaw_bdev(sb->s_bdev, sb);
}
break; break;
case F2FS_GOING_DOWN_METASYNC: case F2FS_GOING_DOWN_METASYNC:
/* do checkpoint only */ /* do checkpoint only */
......
...@@ -433,13 +433,10 @@ xfs_fs_goingdown( ...@@ -433,13 +433,10 @@ xfs_fs_goingdown(
{ {
switch (inflags) { switch (inflags) {
case XFS_FSOP_GOING_FLAGS_DEFAULT: { case XFS_FSOP_GOING_FLAGS_DEFAULT: {
struct super_block *sb = freeze_bdev(mp->m_super->s_bdev); if (!freeze_bdev(mp->m_super->s_bdev)) {
if (sb && !IS_ERR(sb)) {
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT); xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
thaw_bdev(sb->s_bdev, sb); thaw_bdev(mp->m_super->s_bdev);
} }
break; break;
} }
case XFS_FSOP_GOING_FLAGS_LOGFLUSH: case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
......
...@@ -46,6 +46,7 @@ struct block_device { ...@@ -46,6 +46,7 @@ struct block_device {
int bd_fsfreeze_count; int bd_fsfreeze_count;
/* Mutex for freeze */ /* Mutex for freeze */
struct mutex bd_fsfreeze_mutex; struct mutex bd_fsfreeze_mutex;
struct super_block *bd_fsfreeze_sb;
} __randomize_layout; } __randomize_layout;
/* /*
......
...@@ -2020,7 +2020,7 @@ static inline int sync_blockdev(struct block_device *bdev) ...@@ -2020,7 +2020,7 @@ static inline int sync_blockdev(struct block_device *bdev)
#endif #endif
int fsync_bdev(struct block_device *bdev); int fsync_bdev(struct block_device *bdev);
struct super_block *freeze_bdev(struct block_device *bdev); int freeze_bdev(struct block_device *bdev);
int thaw_bdev(struct block_device *bdev, struct super_block *sb); int thaw_bdev(struct block_device *bdev);
#endif /* _LINUX_BLKDEV_H */ #endif /* _LINUX_BLKDEV_H */
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