From: Sergei Shtepa <sergei.shtepa@veeam.com>
To: Christoph Hellwig <hch@infradead.org>,
Hannes Reinecke <hare@suse.de>, Mike Snitzer <snitzer@redhat.com>,
Alasdair Kergon <agk@redhat.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>, <dm-devel@redhat.com>,
<linux-fsdevel@vger.kernel.org>, <linux-block@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <sergei.shtepa@veeam.com>, <pavel.tide@veeam.com>
Subject: [PATCH v8 4/4] fix origin_map - don't split a bio for the origin device if it does not have registered snapshots.
Date: Fri, 9 Apr 2021 14:48:04 +0300 [thread overview]
Message-ID: <1617968884-15149-5-git-send-email-sergei.shtepa@veeam.com> (raw)
In-Reply-To: <1617968884-15149-1-git-send-email-sergei.shtepa@veeam.com>
Signed-off-by: Sergei Shtepa <sergei.shtepa@veeam.com>
---
drivers/md/dm-snap.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 11890db71f3f..81e8e3bb6d25 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -2685,11 +2685,18 @@ static int origin_map(struct dm_target *ti, struct bio *bio)
if (bio_data_dir(bio) != WRITE)
return DM_MAPIO_REMAPPED;
- available_sectors = o->split_boundary -
- ((unsigned)bio->bi_iter.bi_sector & (o->split_boundary - 1));
+ /*
+ * If no snapshot is connected to origin, then split_boundary
+ * will be set to zero. In this case, we don't need to split a bio.
+ */
+ if (o->split_boundary) {
+ available_sectors = o->split_boundary -
+ ((unsigned int)bio->bi_iter.bi_sector &
+ (o->split_boundary - 1));
- if (bio_sectors(bio) > available_sectors)
- dm_accept_partial_bio(bio, available_sectors);
+ if (bio_sectors(bio) > available_sectors)
+ dm_accept_partial_bio(bio, available_sectors);
+ }
/* Only tell snapshots if this is a write */
return do_origin(o->dev, bio, true);
--
2.20.1
next prev parent reply other threads:[~2021-04-09 11:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-09 11:48 [PATCH v8 0/4] block device interposer Sergei Shtepa
2021-04-09 11:48 ` [PATCH v8 1/4] Adds blk_interposer. It allows to redirect bio requests to another block device Sergei Shtepa
2021-04-09 11:48 ` [PATCH v8 2/4] Adds the blk_interposers logic to __submit_bio_noacct() Sergei Shtepa
2021-04-09 11:48 ` [PATCH v8 3/4] Adds blk_interposer to md Sergei Shtepa
2021-04-09 14:12 ` kernel test robot
2021-04-09 14:39 ` kernel test robot
2021-04-09 17:03 ` kernel test robot
2021-04-09 17:03 ` [RFC PATCH] __dm_attach_interposer() can be static kernel test robot
2021-04-09 11:48 ` Sergei Shtepa [this message]
2021-04-09 15:23 ` [PATCH v8 0/4] block device interposer Mike Snitzer
2021-04-13 10:12 ` Sergei Shtepa
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