| From: Theodore Ts'o <tytso@mit.edu> |
| Date: Sun, 30 Dec 2018 23:20:39 -0500 |
| Subject: 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> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| fs/ext4/super.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/fs/ext4/super.c |
| +++ b/fs/ext4/super.c |
| @@ -4712,7 +4712,7 @@ static int ext4_commit_super(struct supe |
| BUFFER_TRACE(sbh, "marking dirty"); |
| ext4_superblock_csum_set(sb); |
| lock_buffer(sbh); |
| - 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 |
