diff options
| author | Joe Thornber <ejt@redhat.com> | 2015-04-22 16:42:35 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2015-06-11 17:13:00 -0400 |
| commit | 028ae9f76f2935e8cf9974bff9a4587e3a995ff3 (patch) | |
| tree | 1bd3984690e112d03cf1e56d43b32c000e420ab4 /drivers/md/dm-cache-policy-mq.c | |
| parent | 88bf5184fa5861e766e39fd34fc6d21557ac7be8 (diff) | |
dm cache: add fail io mode and needs_check flag
If a cache metadata operation fails (e.g. transaction commit) the
cache's metadata device will abort the current transaction, set a new
needs_check flag, and the cache will transition to "read-only" mode. If
aborting the transaction or setting the needs_check flag fails the cache
will transition to "fail-io" mode.
Once needs_check is set the cache device will not be allowed to
activate. Activation requires write access to metadata. Future work is
needed to add proper support for running the cache in read-only mode.
Once in fail-io mode the cache will report a status of "Fail".
Also, add commit() wrapper that will disallow commits if in read_only or
fail mode.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-cache-policy-mq.c')
| -rw-r--r-- | drivers/md/dm-cache-policy-mq.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/md/dm-cache-policy-mq.c b/drivers/md/dm-cache-policy-mq.c index 7cbae125879c..084eec653321 100644 --- a/drivers/md/dm-cache-policy-mq.c +++ b/drivers/md/dm-cache-policy-mq.c @@ -1323,22 +1323,24 @@ static int mq_set_config_value(struct dm_cache_policy *p, return 0; } -static int mq_emit_config_values(struct dm_cache_policy *p, char *result, unsigned maxlen) +static int mq_emit_config_values(struct dm_cache_policy *p, char *result, + unsigned maxlen, ssize_t *sz_ptr) { - ssize_t sz = 0; + ssize_t sz = *sz_ptr; struct mq_policy *mq = to_mq_policy(p); DMEMIT("10 random_threshold %u " "sequential_threshold %u " "discard_promote_adjustment %u " "read_promote_adjustment %u " - "write_promote_adjustment %u", + "write_promote_adjustment %u ", mq->tracker.thresholds[PATTERN_RANDOM], mq->tracker.thresholds[PATTERN_SEQUENTIAL], mq->discard_promote_adjustment, mq->read_promote_adjustment, mq->write_promote_adjustment); + *sz_ptr = sz; return 0; } |