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authorMikulas Patocka <mpatocka@redhat.com>2018-07-03 13:34:22 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-29 13:39:07 +0100
commit07eae146f5b76da9d5bb41bc8825fe486bf0f05a (patch)
tree5ded6573294808b930594b5ffdb52df6c4238154 /block
parent1e9290ca9d6fa96b69c4d6125f87dc77793179e1 (diff)
block: fix infinite loop if the device loses discard capability
[ Upstream commit b88aef36b87c9787a4db724923ec4f57dfd513f3 ] If __blkdev_issue_discard is in progress and a device mapper device is reloaded with a table that doesn't support discard, q->limits.max_discard_sectors is set to zero. This results in infinite loop in __blkdev_issue_discard. This patch checks if max_discard_sectors is zero and aborts with -EOPNOTSUPP. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Zdenek Kabelac <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
-rw-r--r--block/blk-lib.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 53a45663e688..0bdc77888dc5 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -65,6 +65,8 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
*/
req_sects = min_t(sector_t, nr_sects,
q->limits.max_discard_sectors);
+ if (!req_sects)
+ goto fail;
if (req_sects > UINT_MAX >> 9)
req_sects = UINT_MAX >> 9;
@@ -102,6 +104,14 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
*biop = bio;
return 0;
+
+fail:
+ if (bio) {
+ submit_bio_wait(bio);
+ bio_put(bio);
+ }
+ *biop = NULL;
+ return -EOPNOTSUPP;
}
EXPORT_SYMBOL(__blkdev_issue_discard);