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authorChristoph Hellwig <hch@lst.de>2016-07-19 11:23:33 +0200
committerJens Axboe <axboe@fb.com>2016-07-20 17:35:20 -0600
commite950fdf71c9b4a6b63b58fed78956a96cc907402 (patch)
treeeadcf71a0abf034caaab5b019fe8f290df7fbc14 /block
parentb09dcf585df959cf26270e65941ea1f79a1345aa (diff)
downloadlinux-e950fdf71c9b4a6b63b58fed78956a96cc907402.tar.bz2
block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
Currently blkdev_issue_zeroout cascades down from discards (if the driver guarantees that discards zero data), to WRITE SAME and then to a loop writing zeroes. Unfortunately we ignore run-time EOPNOTSUPP errors in the block layer blkdev_issue_discard helper to work around DM volumes that may have mixed discard support underneath. This patch intoroduces a new BLKDEV_DISCARD_ZERO flag to blkdev_issue_discard that indicates we are called for zeroing operation. This allows both to ignore the EOPNOTSUPP hack and actually consolidating the discard_zeroes_data check into the function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-lib.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 78626c2fde33..45b35b15496f 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -36,12 +36,17 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
return -ENXIO;
if (flags & BLKDEV_DISCARD_SECURE) {
+ if (flags & BLKDEV_DISCARD_ZERO)
+ return -EOPNOTSUPP;
if (!blk_queue_secure_erase(q))
return -EOPNOTSUPP;
op = REQ_OP_SECURE_ERASE;
} else {
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
+ if ((flags & BLKDEV_DISCARD_ZERO) &&
+ !q->limits.discard_zeroes_data)
+ return -EOPNOTSUPP;
op = REQ_OP_DISCARD;
}
@@ -116,7 +121,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
&bio);
if (!ret && bio) {
ret = submit_bio_wait(bio);
- if (ret == -EOPNOTSUPP)
+ if (ret == -EOPNOTSUPP && !(flags & BLKDEV_DISCARD_ZERO))
ret = 0;
}
blk_finish_plug(&plug);
@@ -241,11 +246,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, bool discard)
{
- struct request_queue *q = bdev_get_queue(bdev);
-
- if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data &&
- blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0)
- return 0;
+ if (discard) {
+ if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
+ BLKDEV_DISCARD_ZERO))
+ return 0;
+ }
if (bdev_write_same(bdev) &&
blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,