Discard can return -EIO asynchronously if the alignment for the request
isn't suitable for the driver, which makes a proper fallback to other
methods in __blkdev_issue_zeroout impossible. Thus only issue a sync
discard from blkdev_issue_zeroout an don't try discard at all from
__blkdev_issue_zeroout as a non-invasive workaround.
One more reason why abusing discard for zeroing must die..
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Eryu Guan <eguan@xxxxxxxxxx>
Fixes: e73c23ff ("block: add async variant of blkdev_issue_zeroout")
---
block/blk-lib.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index ed89c8f..f8c82a9 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -301,13 +301,6 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
if ((sector | nr_sects) & bs_mask)
return -EINVAL;
- if (discard) {
- ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
- BLKDEV_DISCARD_ZERO, biop);
- if (ret == 0 || (ret && ret != -EOPNOTSUPP))
- goto out;
- }
-
ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
biop);
if (ret == 0 || (ret && ret != -EOPNOTSUPP))
@@ -370,6 +363,12 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
struct bio *bio = NULL;
struct blk_plug plug;
+ if (discard) {
+ if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
+ BLKDEV_DISCARD_ZERO))
+ return 0;
+ }
+
blk_start_plug(&plug);
ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
&bio, discard);
--
2.1.4
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