* re: md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
@ 2013-01-08 13:23 Dan Carpenter
0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2013-01-08 13:23 UTC (permalink / raw)
To: Joe.Lawrence; +Cc: linux-raid
Hello Joe Lawrence,
This is a semi-automatic email about new static checker warnings.
The patch aa992f57bd76: "md: raid1,10: Handle REQ_WRITE_SAME flag in
write bios" from Dec 14, 2012, leads to the following Smatch
complaint:
drivers/md/raid1.c:2861 run()
warn: variable dereferenced before check 'mddev->queue' (see line 2823)
drivers/md/raid1.c
2822
2823 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
^^^^^^^^^^^^
New dereference.
2824 rdev_for_each(rdev, mddev) {
2825 if (!mddev->gendisk)
2826 continue;
2827 disk_stack_limits(mddev->gendisk, rdev->bdev,
2828 rdev->data_offset << 9);
2829 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
2830 discard_supported = true;
2831 }
2832
2833 mddev->degraded = 0;
2834 for (i=0; i < conf->raid_disks; i++)
2835 if (conf->mirrors[i].rdev == NULL ||
2836 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2837 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2838 mddev->degraded++;
2839
2840 if (conf->raid_disks - mddev->degraded == 1)
2841 mddev->recovery_cp = MaxSector;
2842
2843 if (mddev->recovery_cp != MaxSector)
2844 printk(KERN_NOTICE "md/raid1:%s: not clean"
2845 " -- starting background reconstruction\n",
2846 mdname(mddev));
2847 printk(KERN_INFO
2848 "md/raid1:%s: active with %d out of %d mirrors\n",
2849 mdname(mddev), mddev->raid_disks - mddev->degraded,
2850 mddev->raid_disks);
2851
2852 /*
2853 * Ok, everything is just fine now
2854 */
2855 mddev->thread = conf->thread;
2856 conf->thread = NULL;
2857 mddev->private = conf;
2858
2859 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2860
2861 if (mddev->queue) {
^^^^^^^^^^^^
Old check.
2862 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2863 mddev->queue->backing_dev_info.congested_data = mddev;
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
* re: md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
@ 2013-01-08 13:44 Dan Carpenter
2013-01-09 4:11 ` Joe Lawrence
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2013-01-08 13:44 UTC (permalink / raw)
To: Joe.Lawrence; +Cc: linux-raid
Hello Joe Lawrence,
This is a semi-automatic email about new static checker warnings.
The patch aa992f57bd76: "md: raid1,10: Handle REQ_WRITE_SAME flag in
write bios" from Dec 14, 2012, leads to the following Smatch
complaint:
drivers/md/raid10.c:3630 run()
error: we previously assumed 'mddev->queue' could be null (see line 3619)
drivers/md/raid10.c
3618 chunk_size = mddev->chunk_sectors << 9;
3619 if (mddev->queue) {
^^^^^^^^^^^^
Old check.
3620 blk_queue_max_discard_sectors(mddev->queue,
3621 mddev->chunk_sectors);
3622 blk_queue_io_min(mddev->queue, chunk_size);
3623 if (conf->geo.raid_disks % conf->geo.near_copies)
3624 blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
3625 else
3626 blk_queue_io_opt(mddev->queue, chunk_size *
3627 (conf->geo.raid_disks / conf->geo.near_copies));
3628 }
3629
3630 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
^^^^^^^^^^^^
New dereference.
3631 rdev_for_each(rdev, mddev) {
3632 long long diff;
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
* re: md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
2013-01-08 13:44 md: raid1,10: Handle REQ_WRITE_SAME flag in write bios Dan Carpenter
@ 2013-01-09 4:11 ` Joe Lawrence
0 siblings, 0 replies; 3+ messages in thread
From: Joe Lawrence @ 2013-01-09 4:11 UTC (permalink / raw)
To: neilb, linux-raid; +Cc: Joe Lawrence
On Tue, 8 Jan 2013, Dan Carpenter wrote:
> Hello Joe Lawrence,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch aa992f57bd76: "md: raid1,10: Handle REQ_WRITE_SAME flag in
> write bios" from Dec 14, 2012, leads to the following Smatch
> complaint:
>
> drivers/md/raid10.c:3630 run()
> error: we previously assumed 'mddev->queue' could be null (see line 3619)
>
> drivers/md/raid10.c
> 3618 chunk_size = mddev->chunk_sectors << 9;
> 3619 if (mddev->queue) {
> ^^^^^^^^^^^^
> Old check.
>
> 3620 blk_queue_max_discard_sectors(mddev->queue,
> 3621 mddev->chunk_sectors);
> 3622 blk_queue_io_min(mddev->queue, chunk_size);
> 3623 if (conf->geo.raid_disks % conf->geo.near_copies)
> 3624 blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
> 3625 else
> 3626 blk_queue_io_opt(mddev->queue, chunk_size *
> 3627 (conf->geo.raid_disks / conf->geo.near_copies));
> 3628 }
> 3629
> 3630 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
> ^^^^^^^^^^^^
> New dereference.
>
> 3631 rdev_for_each(rdev, mddev) {
> 3632 long long diff;
>
> regards,
> dan carpenter
>
Hi Neil,
Here's a revised patch that should make the static checker happy. If you
prefer a second patch instead, let me know.
Regards,
-- Joe
From 414901de959ea1873187fa3fecf2f00b107d40e2 Mon Sep 17 00:00:00 2001
From: Joe Lawrence <joe.lawrence@stratus.com>
Date: Tue, 8 Jan 2013 23:02:38 -0500
Subject: [PATCH 4/4] md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
Set mddev queue's max_write_same_sectors to its chunk_sector value (before
disk_stack_limits merges the underlying disk limits.) With that in place,
be sure to handle writes coming down from the block layer that have the
REQ_WRITE_SAME flag set. That flag needs to be copied into any newly cloned
write bio.
Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
---
drivers/md/raid1.c | 7 ++++++-
drivers/md/raid10.c | 9 +++++++--
2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d5bddfc..6e5d5a5 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1000,6 +1000,7 @@ static void make_request(struct mddev *mddev, struct bio * bio)
const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
const unsigned long do_discard = (bio->bi_rw
& (REQ_DISCARD | REQ_SECURE));
+ const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
struct md_rdev *blocked_rdev;
struct blk_plug_cb *cb;
struct raid1_plug_cb *plug = NULL;
@@ -1301,7 +1302,8 @@ read_again:
conf->mirrors[i].rdev->data_offset);
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_flush_fua | do_sync | do_discard;
+ mbio->bi_rw =
+ WRITE | do_flush_fua | do_sync | do_discard | do_same;
mbio->bi_private = r1_bio;
atomic_inc(&r1_bio->remaining);
@@ -2818,6 +2820,9 @@ static int run(struct mddev *mddev)
if (IS_ERR(conf))
return PTR_ERR(conf);
+ if (mddev->queue)
+ blk_queue_max_write_same_sectors(mddev->queue,
+ mddev->chunk_sectors);
rdev_for_each(rdev, mddev) {
if (!mddev->gendisk)
continue;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 64d4824..1a74c12 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1105,6 +1105,7 @@ static void make_request(struct mddev *mddev, struct bio * bio)
const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
const unsigned long do_discard = (bio->bi_rw
& (REQ_DISCARD | REQ_SECURE));
+ const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
unsigned long flags;
struct md_rdev *blocked_rdev;
struct blk_plug_cb *cb;
@@ -1460,7 +1461,8 @@ retry_write:
rdev));
mbio->bi_bdev = rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+ mbio->bi_rw =
+ WRITE | do_sync | do_fua | do_discard | do_same;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
@@ -1502,7 +1504,8 @@ retry_write:
r10_bio, rdev));
mbio->bi_bdev = rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+ mbio->bi_rw =
+ WRITE | do_sync | do_fua | do_discard | do_same;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
@@ -3569,6 +3572,8 @@ static int run(struct mddev *mddev)
if (mddev->queue) {
blk_queue_max_discard_sectors(mddev->queue,
mddev->chunk_sectors);
+ blk_queue_max_write_same_sectors(mddev->queue,
+ mddev->chunk_sectors);
blk_queue_io_min(mddev->queue, chunk_size);
if (conf->geo.raid_disks % conf->geo.near_copies)
blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
--
1.7.11.7
^ permalink raw reply related [flat|nested] 3+ messages in thread
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