From: Mike Snitzer <snitzer@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, dm-devel@redhat.com,
Vijayendra Suman <vijayendra.suman@oracle.com>,
Ming Lei <ming.lei@redhat.com>
Subject: [PATCH v2 1/4] block: use lcm_not_zero() when stacking chunk_sectors
Date: Tue, 15 Sep 2020 13:23:54 -0400 [thread overview]
Message-ID: <20200915172357.83215-2-snitzer@redhat.com> (raw)
In-Reply-To: <20200915172357.83215-1-snitzer@redhat.com>
Like 'io_opt', blk_stack_limits() should stack 'chunk_sectors' using
lcm_not_zero() rather than min_not_zero() -- otherwise the final
'chunk_sectors' could result in sub-optimal alignment of IO to
component devices in the IO stack.
Also, if 'chunk_sectors' isn't a multiple of 'physical_block_size'
then it is a bug in the driver and the device should be flagged as
'misaligned'.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
block/blk-settings.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 76a7e03bcd6c..b2e1a929a6db 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -534,6 +534,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
t->io_min = max(t->io_min, b->io_min);
t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
+ t->chunk_sectors = lcm_not_zero(t->chunk_sectors, b->chunk_sectors);
/* Physical block size a multiple of the logical block size? */
if (t->physical_block_size & (t->logical_block_size - 1)) {
@@ -556,6 +557,13 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
ret = -1;
}
+ /* chunk_sectors a multiple of the physical block size? */
+ if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
+ t->chunk_sectors = 0;
+ t->misaligned = 1;
+ ret = -1;
+ }
+
t->raid_partial_stripes_expensive =
max(t->raid_partial_stripes_expensive,
b->raid_partial_stripes_expensive);
@@ -594,10 +602,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
t->discard_granularity;
}
- if (b->chunk_sectors)
- t->chunk_sectors = min_not_zero(t->chunk_sectors,
- b->chunk_sectors);
-
t->zoned = max(t->zoned, b->zoned);
return ret;
}
--
2.15.0
next prev parent reply other threads:[~2020-09-15 17:23 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 17:23 [PATCH v2 0/4] block: a couple chunk_sectors fixes/improvements Mike Snitzer
2020-09-15 17:23 ` Mike Snitzer [this message]
2020-09-15 17:23 ` [PATCH v2 2/4] block: allow 'chunk_sectors' to be non-power-of-2 Mike Snitzer
2020-09-15 17:23 ` [PATCH v2 3/4] dm table: stack 'chunk_sectors' limit to account for target-specific splitting Mike Snitzer
2020-09-15 17:23 ` [PATCH v2 4/4] dm: unconditionally call blk_queue_split() in dm_process_bio() Mike Snitzer
2020-09-16 1:08 ` Ming Lei
2020-09-16 1:28 ` Mike Snitzer
2020-09-16 1:48 ` Ming Lei
2020-09-16 3:39 ` Mike Snitzer
2020-09-16 7:51 ` Ming Lei
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