path: root/block
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authorJens Axboe <axboe@fb.com>2014-02-12 09:34:01 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-22 12:41:28 -0800
commit163d66d4fb1009d51027286cc4b921a5928961fc (patch)
tree8ae4796a6a289bf0fd27538fd4ca86a0b92a13bf /block
parentcaaeac355477b49d6b50791fb6f0ced3d2b4e93b (diff)
block: add cond_resched() to potentially long running ioctl discard loop
commit c8123f8c9cb517403b51aa41c3c46ff5e10b2c17 upstream. When mkfs issues a full device discard and the device only supports discards of a smallish size, we can loop in blkdev_issue_discard() for a long time. If preempt isn't enabled, this can turn into a softlock situation and the kernel will start complaining. Add an explicit cond_resched() at the end of the loop to avoid that. Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
1 files changed, 8 insertions, 0 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index d6f50d572565..9a32f5868fb9 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -121,6 +121,14 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
submit_bio(type, bio);
+ /*
+ * We can loop for a long time in here, if someone does
+ * full device discards (like mkfs). Be nice and allow
+ * us to schedule out to avoid softlocking if preempt
+ * is disabled.
+ */
+ cond_resched();