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authorKazuya Mio <k-mio@sx.jp.nec.com>2011-12-01 16:51:07 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-21 09:40:05 -0700
commitfcb2c2e95085336d1d6ac9cc1a07a783f80e60c0 (patch)
treea4a1c6711f080f97ad50cf9a2c50f7b0a9684cab /fs
parent9f5ad2813ceb238c44807d952542b19ff7cb0525 (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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/super.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c
index ab3d672db0de..caf4dfa28eed 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1009,6 +1009,8 @@ 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;
}