diff options
| author | Joe Thornber <ejt@redhat.com> | 2019-01-15 13:27:01 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2019-01-15 16:10:41 -0500 |
| commit | d445bd9cec1a850c2100fcf53684c13b3fd934f2 (patch) | |
| tree | abca30179b3fa5355959344f50c57dce9213ef55 /drivers/md/dm-thin.c | |
| parent | 1856b9f7bcc8e9bdcccc360aabb56fbd4dd6c565 (diff) | |
dm thin: fix passdown_double_checking_shared_status()
Commit 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next
stage processing") changed process_prepared_discard_passdown_pt1() to
increment all the blocks being discarded until after the passdown had
completed to avoid them being prematurely reused.
IO issued to a thin device that breaks sharing with a snapshot, followed
by a discard issued to snapshot(s) that previously shared the block(s),
results in passdown_double_checking_shared_status() being called to
iterate through the blocks double checking their reference count is zero
and issuing the passdown if so. So a side effect of commit 00a0ea33b495
is passdown_double_checking_shared_status() was broken.
Fix this by checking if the block reference count is greater than 1.
Also, rename dm_pool_block_is_used() to dm_pool_block_is_shared().
Fixes: 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next stage processing")
Cc: stable@vger.kernel.org # 4.9+
Reported-by: ryan.p.norwood@gmail.com
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-thin.c')
| -rw-r--r-- | drivers/md/dm-thin.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index dadd9696340c..ca8af21bf644 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -1048,7 +1048,7 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m * passdown we have to check that these blocks are now unused. */ int r = 0; - bool used = true; + bool shared = true; struct thin_c *tc = m->tc; struct pool *pool = tc->pool; dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin; @@ -1058,11 +1058,11 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m while (b != end) { /* find start of unmapped run */ for (; b < end; b++) { - r = dm_pool_block_is_used(pool->pmd, b, &used); + r = dm_pool_block_is_shared(pool->pmd, b, &shared); if (r) goto out; - if (!used) + if (!shared) break; } @@ -1071,11 +1071,11 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m /* find end of run */ for (e = b + 1; e != end; e++) { - r = dm_pool_block_is_used(pool->pmd, e, &used); + r = dm_pool_block_is_shared(pool->pmd, e, &shared); if (r) goto out; - if (used) + if (shared) break; } |