[PATCH 3.8 037/166] dm thin: always fallback the pool mode if commit fails

Kamal Mostafa
2014-01-15T21:50:51Z

From: Joe Thornber <ejt@redhat.com>

commit 020cc3b5e28c2e24f59f53a9154faf08564f308e upstream.

Rename commit_or_fallback() to commit(). Now all previous calls to
commit() will trigger the pool mode to fallback if the commit fails.

Also, check the error returned from commit() in alloc_data_block().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/md/dm-thin.c | 36 +++++++++++++++---------------------
1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index c29e967..7ac3dd4 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -810,31 +810,23 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
}
}

-static int commit(struct pool *pool)
-{
- int r;
-
- r = dm_pool_commit_metadata(pool->pmd);
- if (r)
- DMERR_LIMIT("commit failed: error = %d", r);
-
- return r;
-}
-
/*
* A non-zero return indicates read_only or fail_io mode.
* Many callers don't care about the return value.
*/
-static int commit_or_fallback(struct pool *pool)
+static int commit(struct pool *pool)
{
int r;

if (get_pool_mode(pool) != PM_WRITE)
return -EINVAL;

- r = commit(pool);
- if (r)
+ r = dm_pool_commit_metadata(pool->pmd);
+ if (r) {
+ DMERR_LIMIT("%s: dm_pool_commit_metadata failed: error = %d",
+ dm_device_name(pool->pool_md), r);
set_pool_mode(pool, PM_READ_ONLY);
+ }

return r;
}
@@ -867,7 +859,9 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
* Try to commit to see if that will free up some
* more space.
*/
- (void) commit_or_fallback(pool);
+ r = commit(pool);
+ if (r)
+ return r;

r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r)
@@ -1271,7 +1265,7 @@ static void process_deferred_bios(struct pool *pool)
if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
return;

- if (commit_or_fallback(pool)) {
+ if (commit(pool)) {
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
return;
@@ -2056,7 +2050,7 @@ static int pool_preresume(struct dm_target *ti)
return r;
}

- (void) commit_or_fallback(pool);
+ (void) commit(pool);
}

return 0;
@@ -2084,7 +2078,7 @@ static void pool_postsuspend(struct dm_target *ti)

cancel_delayed_work(&pool->waker);
flush_workqueue(pool->wq);
- (void) commit_or_fallback(pool);
+ (void) commit(pool);
}

static int check_arg_count(unsigned argc, unsigned args_required)
@@ -2218,7 +2212,7 @@ static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct
if (r)
return r;

- (void) commit_or_fallback(pool);
+ (void) commit(pool);

r = dm_pool_reserve_metadata_snap(pool->pmd);
if (r)
@@ -2280,7 +2274,7 @@ static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
DMWARN("Unrecognised thin pool target message received: %s", argv[0]);

if (!r)
- (void) commit_or_fallback(pool);
+ (void) commit(pool);

return r;
}
@@ -2335,7 +2329,7 @@ static void pool_status(struct dm_target *ti, status_type_t type,

/* Commit to ensure statistics aren't out-of-date */
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
- (void) commit_or_fallback(pool);
+ (void) commit(pool);

r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
if (r) {
--
1.8.3.2