On Mon, Feb 12, 2018 at 12:20:43PM +1100, NeilBrown wrote: > > tune2fs currently replays the journal if it needs > recovery and the filesystem isn't mounted. > > The test for "is the filesystem mounted" isn't completely robust. > Lustre makes use of ext4 filesystems in a way that they are mounted > without being visible in /proc/mounts or similar. > This usage can easily be detected by attempting to open the device > with O_EXCL. tune2fs already does this and the EXT2_MF_BUSY flag > is set if open(O_EXCL) fails. > Several uses other than lustre mounts could cause O_EXCL to fail, > but in any case it seems unwise to recover the journal when something > else is keeping the device busy. > > So add an extra test to avoid journal recovery when the device > is busy. This fixes some problems with lustre usage. > > Signed-off-by: NeilBrown <neilb@xxxxxxxx> > > -- > Note: it seems wrong to recover the journal *after* making > changes to the superblock - there is a good chance that > recovering the journal will over-write those changes. > This is what was happening that lead me to this problem. > Shouldn't journal recovery happen *first*?? Yes. Oops. :/ This whole hunk ought to move up to be right after ext2fs_check_if_mounted, I think. As for this patch itself, Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --D
