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authorMike Snitzer <snitzer@redhat.com>2016-05-05 11:54:21 -0400
committerJens Axboe <axboe@fb.com>2016-05-05 13:03:26 -0600
commitbbd848e0fade51ae51dab86a0683069cef89953f (patch)
tree1f3a5d8107fe664a19ebddf4f656b0f50fe267b5
parenta21f2a3ec62abe2e06500d6550659a0ff5624fbb (diff)
downloadlinux-bbd848e0fade51ae51dab86a0683069cef89953f.tar.bz2
block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard
Commit 38f25255330 ("block: add __blkdev_issue_discard") incorrectly disallowed the early return of -EOPNOTSUPP if the device doesn't support discard (or secure discard). This early return of -EOPNOTSUPP has always been part of blkdev_issue_discard() interface so there isn't a good reason to break that behaviour -- especially when it can be easily reinstated. The nuance of allowing early return of -EOPNOTSUPP vs disallowing late return of -EOPNOTSUPP is: if the overall device never advertised support for discards and one is issued to the device it is beneficial to inform the caller that discards are not supported via -EOPNOTSUPP. But if a device advertises discard support it means that at least a subset of the device does have discard support -- but it could be that discards issued to some regions of a stacked device will not be supported. In that case the late return of -EOPNOTSUPP must be disallowed. Fixes: 38f25255330 ("block: add __blkdev_issue_discard") Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-lib.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index ccbce2b2ea05..23d7f301a196 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -109,11 +109,14 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
blk_start_plug(&plug);
ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, type,
&bio);
- if (!ret && bio)
+ if (!ret && bio) {
ret = submit_bio_wait(type, bio);
+ if (ret == -EOPNOTSUPP)
+ ret = 0;
+ }
blk_finish_plug(&plug);
- return ret != -EOPNOTSUPP ? ret : 0;
+ return ret;
}
EXPORT_SYMBOL(blkdev_issue_discard);