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authorTheodore Ts'o <tytso@mit.edu>2018-12-30 23:20:39 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-01-16 22:03:26 +0100
commit3f98cd7a87d06fe4f21f8a48f3318bf576bfcc4e (patch)
parent88a35247f8b6b260f011e490615af5ee5766303f (diff)
ext4: avoid kernel warning when writing the superblock to a dead device
commit e86807862e6880809f191c4cea7f88a489f0ed34 upstream. The xfstests generic/475 test switches the underlying device with dm-error while running a stress test. This results in a large number of file system errors, and since we can't lock the buffer head when marking the superblock dirty in the ext4_grp_locked_error() case, it's possible the superblock to be !buffer_uptodate() without buffer_write_io_error() being true. We need to set buffer_uptodate() before we call mark_buffer_dirty() or this will trigger a WARN_ON. It's safe to do this since the superblock must have been properly read into memory or the mount would have been successful. So if buffer_uptodate() is not set, we can safely assume that this happened due to a failed attempt to write the superblock. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6641a1b8a6a5..521320de2017 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4905,7 +4905,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
if (sync)
- if (buffer_write_io_error(sbh)) {
+ if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
* Oh, dear. A previous attempt to write the
* superblock failed. This could happen because the