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| author | Yu Kuai <yukuai3@huawei.com> | 2023-10-07 19:21:05 +0800 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2023-10-09 16:32:02 -0700 |
| commit | 9e55a22fce1384837c213274d1a3b93be16ed9d7 (patch) | |
| tree | 432bc867785b16614cf6a31a8f3879b3ca6e5097 /drivers | |
| parent | 09f894affcf2daac5aa841ffff43d1242215fd80 (diff) | |
| download | linux-stable-9e55a22fce1384837c213274d1a3b93be16ed9d7.tar.gz linux-stable-9e55a22fce1384837c213274d1a3b93be16ed9d7.tar.bz2 linux-stable-9e55a22fce1384837c213274d1a3b93be16ed9d7.zip | |
md/raid1: don't split discard io for write behind
Currently, discad io is treated the same as normal write io, and for
write behind case, io size is limited to:
BIO_MAX_VECS * (PAGE_SIZE >> 9)
For 0.5KB sector size and 4KB PAGE_SIZE, this is just 1MB. For
consequence, if 'WriteMostly' is set to one of the underlying disks,
then diskcard io will be splited into 1MB and it will take a long time
for the diskcard to finish.
Fix this problem by disable write behind for discard io.
Reported-by: Roman Mamedov <rm@romanrm.net>
Closes: https://lore.kernel.org/all/6a1165f7-c792-c054-b8f0-1ad4f7b8ae01@ultracoder.org/
Reported-and-tested-by: Kirill Kirilenko <kirill@ultracoder.org>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231007112105.407449-1-yukuai1@huaweicloud.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/raid1.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 3a78f79ee6d5..35d12948e0a9 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1345,6 +1345,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, int first_clone; int max_sectors; bool write_behind = false; + bool is_discard = (bio_op(bio) == REQ_OP_DISCARD); if (mddev_is_clustered(mddev) && md_cluster_ops->area_resyncing(mddev, WRITE, @@ -1405,7 +1406,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, * write-mostly, which means we could allocate write behind * bio later. */ - if (rdev && test_bit(WriteMostly, &rdev->flags)) + if (!is_discard && rdev && test_bit(WriteMostly, &rdev->flags)) write_behind = true; if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |