diff options
| author | Jens Axboe <axboe@fb.com> | 2014-02-12 09:34:01 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-04-02 00:58:51 +0100 |
| commit | e5b56dda4701918b565764e47a60aa252964411c (patch) | |
| tree | ab3a2e45ade0670d3be8ddbd267ec819daf6c1e8 | |
| parent | b5b0899755964724d1a2cccd472c8051186edc15 (diff) | |
| download | lwn-e5b56dda4701918b565764e47a60aa252964411c.tar.gz lwn-e5b56dda4701918b565764e47a60aa252964411c.zip | |
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: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | block/blk-lib.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index 2b461b496a78..36751e211bb8 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -101,6 +101,14 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, atomic_inc(&bb.done); 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(); } /* Wait for bios in-flight */ |