Otherwise, blk_validate_limits() will throw-away the max_sectors that
was stacked from underlying device(s). In doing so it can set a
max_sectors limit that violates underlying device limits.
This caused dm-multipath IO failures like the following because the
underlying devices' max_sectors were stacked up to be 1024, yet
blk_validate_limits() defaulted max_sectors to BLK_DEF_MAX_SECTORS_CAP
(2560):
[ 1214.673233] blk_insert_cloned_request: over max size limit. (2048 > 1024)
[ 1214.673267] device-mapper: multipath: 254:3: Failing path 8:32.
[ 1214.675196] blk_insert_cloned_request: over max size limit. (2048 > 1024)
[ 1214.675224] device-mapper: multipath: 254:3: Failing path 8:16.
[ 1214.675309] blk_insert_cloned_request: over max size limit. (2048 > 1024)
[ 1214.675338] device-mapper: multipath: 254:3: Failing path 8:48.
[ 1214.675413] blk_insert_cloned_request: over max size limit. (2048 > 1024)
[ 1214.675441] device-mapper: multipath: 254:3: Failing path 8:64.
The initial bug report included:
[ 13.822701] blk_insert_cloned_request: over max size limit. (248 > 128)
[ 13.829351] device-mapper: multipath: 253:3: Failing path 8:32.
[ 13.835307] blk_insert_cloned_request: over max size limit. (248 > 128)
[ 13.841928] device-mapper: multipath: 253:3: Failing path 65:16.
[ 13.844532] blk_insert_cloned_request: over max size limit. (248 > 128)
[ 13.854363] blk_insert_cloned_request: over max size limit. (248 > 128)
[ 13.854580] device-mapper: multipath: 253:4: Failing path 8:48.
[ 13.861166] device-mapper: multipath: 253:3: Failing path 8:192.
Reported-by: Marco Patalano <mpatalan@xxxxxxxxxx>
Reported-by: Ewan Milne <emilne@xxxxxxxxxx>
Fixes: 1c0e720228ad ("dm: use queue_limits_set")
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-table.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 88114719fe18..6463b4afeaa4 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1961,6 +1961,7 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
bool wc = false, fua = false;
+ unsigned int max_hw_sectors;
int r;
if (dm_table_supports_nowait(t))
@@ -1981,9 +1982,16 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
if (!dm_table_supports_secure_erase(t))
limits->max_secure_erase_sectors = 0;
+ /* Don't allow queue_limits_set() to throw-away stacked max_sectors */
+ max_hw_sectors = limits->max_hw_sectors;
+ limits->max_hw_sectors = limits->max_sectors;
r = queue_limits_set(q, limits);
if (r)
return r;
+ /* Restore stacked max_hw_sectors */
+ mutex_lock(&q->limits_lock);
+ limits->max_hw_sectors = max_hw_sectors;
+ mutex_unlock(&q->limits_lock);
if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
wc = true;
--
2.43.0
