From: Jonathan Brassow Date: Wed, 9 May 2007 09:33:08 +0000 (-0700) Subject: dm log: fix resume failed log device X-Git-Tag: MMI-PSA29.97-13-9~43432 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ba8b45cea5f632540d561d37d94c71c07f6af1aa;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git dm log: fix resume failed log device This patch removes the possibility of having uninitialized log state if the log device has failed. When a mirror resumes operation, it calls 'resume' on the logging module. If disk based logging is being used, the log device is read to fill in the log state. If the log device has failed, we cannot simply return, because this would leave the in-memory log state uninitialized. Instead, we assume all regions are out-of-sync and reset the log state. Failure to do this could result in the logging code reporting a region as in-sync, even though it isn't; which could result in a corrupted mirror. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index a60acf8d385a..a66428d860fe 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -478,7 +478,14 @@ static int disk_resume(struct dirty_log *log) DMWARN("%s: Failed to read header on mirror log device", lc->log_dev->name); fail_log_device(lc); - return r; + /* + * If the log device cannot be read, we must assume + * all regions are out-of-sync. If we simply return + * here, the state will be uninitialized and could + * lead us to return 'in-sync' status for regions + * that are actually 'out-of-sync'. + */ + lc->header.nr_regions = 0; } /* set or clear any new bits -- device has grown */