diff options
| author | Kazuya Mio <k-mio@sx.jp.nec.com> | 2011-12-01 16:51:07 +0900 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-05-31 00:43:54 +0100 |
| commit | 42bbdb289122169ec6d4f2a4bec848491c4408a7 (patch) | |
| tree | b36456b346cb3be18f8ed8f2a9b670faf86053e0 | |
| parent | d2b6ee559fe72ec90da4eb623f3f01135c5a1ec7 (diff) | |
wake up s_wait_unfrozen when ->freeze_fs fails
commit e1616300a20c80396109c1cf013ba9a36055a3da upstream.
dd slept infinitely when fsfeeze failed because of EIO.
To fix this problem, if ->freeze_fs fails, freeze_super() wakes up
the tasks waiting for the filesystem to become unfrozen.
When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(),
the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen.
However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then
freeze_super() returns an error number. In this case, FITHAW ioctl returns
EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up
s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely.
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | fs/super.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index afd0f1ad45e..2a698f6a3c2 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1166,6 +1166,8 @@ int freeze_super(struct super_block *sb) printk(KERN_ERR "VFS:Filesystem freeze failed\n"); sb->s_frozen = SB_UNFROZEN; + smp_wmb(); + wake_up(&sb->s_wait_unfrozen); deactivate_locked_super(sb); return ret; } |