[PATCH 4/5] fsfreeze: switch to using super methods everywhere

From: Dave Chinner
Date: Thu Jun 10 2010 - 03:21:48 EST


From: Dave Chinner <dchinner@xxxxxxxxxx>

freeze/thaw_bdev are now just trivial wrappers around
freeze/thaw_super(). Convert all users of the bdev interfaces to use
the superblock interfaces instead, and remove the bdev interfaces.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
drivers/md/dm.c | 13 +++++++----
fs/block_dev.c | 54 ----------------------------------------------------
fs/buffer.c | 2 +-
fs/super.c | 1 +
fs/xfs/xfs_fsops.c | 10 ++------
include/linux/fs.h | 19 ------------------
6 files changed, 13 insertions(+), 86 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index d21e128..70d5fd6 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2427,15 +2427,18 @@ static int lock_fs(struct mapped_device *md)

WARN_ON(md->frozen_sb);

- md->frozen_sb = freeze_bdev(md->bdev);
- if (IS_ERR(md->frozen_sb)) {
- r = PTR_ERR(md->frozen_sb);
+ md->frozen_sb = get_active_super(md->bdev);
+ if (!md->frozen_sb)
+ return -EIO;
+ r = freeze_super(md->frozen_sb);
+ if (r) {
+ deactivate_super(md->frozen_sb);
md->frozen_sb = NULL;
return r;
}
+ deactivate_super(md->frozen_sb);

set_bit(DMF_FROZEN, &md->flags);
-
return 0;
}

@@ -2444,7 +2447,7 @@ static void unlock_fs(struct mapped_device *md)
if (!test_bit(DMF_FROZEN, &md->flags))
return;

- thaw_bdev(md->bdev, md->frozen_sb);
+ thaw_super(md->frozen_sb);
md->frozen_sb = NULL;
clear_bit(DMF_FROZEN, &md->flags);
}
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 84899b3..3c3d1fe 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -213,60 +213,6 @@ int fsync_bdev(struct block_device *bdev)
}
EXPORT_SYMBOL(fsync_bdev);

-/**
- * freeze_bdev -- lock a filesystem and force it into a consistent state
- * @bdev: blockdevice to lock
- *
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
- struct super_block *sb;
- int error = 0;
-
- sb = get_active_super(bdev);
- if (!sb)
- goto out;
- error = freeze_super(sb);
- if (error) {
- deactivate_super(sb);
- return ERR_PTR(error);
- }
- deactivate_super(sb);
- out:
- sync_blockdev(bdev);
- return sb; /* thaw_bdev releases s->s_umount */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev -- unlock filesystem
- * @bdev: blockdevice to unlock
- * @sb: associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
- if (!sb)
- return -EINVAL;
- return thaw_super(sb);
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-int thaw_bdev_emergency(struct block_device *bdev, struct super_block *sb)
-{
- if (!sb)
- return -EINVAL;
- return thaw_super_emergency(sb);
-}
-
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, blkdev_get_block, wbc);
diff --git a/fs/buffer.c b/fs/buffer.c
index f0c55d9..b095fc1 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -564,7 +564,7 @@ repeat:
static void do_thaw_one(struct super_block *sb, void *unused)
{
char b[BDEVNAME_SIZE];
- while (sb->s_bdev && !thaw_bdev_emergency(sb->s_bdev, sb))
+ while (sb->s_bdev && !thaw_super_emergency(sb))
printk(KERN_WARNING "Emergency Thaw on %s\n",
bdevname(sb->s_bdev, b));
}
diff --git a/fs/super.c b/fs/super.c
index 5f13431..81a4034 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -976,6 +976,7 @@ int freeze_super(struct super_block *sb)
}
}
out_active:
+ sync_blockdev(sb->s_bdev);
up_write(&sb->s_umount);
out_unlock:
mutex_unlock(&sb->s_freeze_mutex);
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 37a6f62..cc993a5 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -642,16 +642,12 @@ xfs_fs_goingdown(
__uint32_t inflags)
{
switch (inflags) {
- case XFS_FSOP_GOING_FLAGS_DEFAULT: {
- struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
-
- if (sb && !IS_ERR(sb)) {
+ case XFS_FSOP_GOING_FLAGS_DEFAULT:
+ if (!freeze_super(mp->m_super)) {
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
- thaw_bdev(sb->s_bdev, sb);
+ thaw_super(mp->m_super);
}
-
break;
- }
case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
break;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f92b077..39bf4ac 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1951,30 +1951,11 @@ extern void invalidate_bdev(struct block_device *);
extern int sync_blockdev(struct block_device *bdev);
extern struct super_block *freeze_bdev(struct block_device *);
extern void emergency_thaw_all(void);
-extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
-extern int thaw_bdev_emergency(struct block_device *bdev,
- struct super_block *sb);
extern int fsync_bdev(struct block_device *);
#else
static inline void bd_forget(struct inode *inode) {}
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
static inline void invalidate_bdev(struct block_device *bdev) {}
-
-static inline struct super_block *freeze_bdev(struct block_device *sb)
-{
- return NULL;
-}
-
-static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
- return 0;
-}
-
-static inline int thaw_bdev_emergency(struct block_device *bdev,
- struct super_block *sb)
-{
- return 0;
-}
#endif
extern int sync_filesystem(struct super_block *);
extern const struct file_operations def_blk_fops;
--
1.7.1

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