On 12/25/21 9:02 PM, Vishal Verma wrote:
On 12/25/21 5:07 PM, Song Liu wrote:
On Sat, Dec 25, 2021 at 2:13 PM Vishal Verma
<vverma@xxxxxxxxxxxxxxxx> wrote:
On 12/25/21 12:28 AM, Vishal Verma wrote:
On 12/24/21 7:14 PM, Song Liu wrote:
On Tue, Dec 21, 2021 at 12:06 PM Vishal
Verma<vverma@xxxxxxxxxxxxxxxx> wrote:
Returns EAGAIN in case the raid456 driver would block
waiting for situations like:
- Reshape operation,
- Discard operation.
Signed-off-by: Vishal Verma<vverma@xxxxxxxxxxxxxxxx>
I think we will need the following fix for raid456:
Ack
============================ 8< ============================
diff --git i/drivers/md/raid5.c w/drivers/md/raid5.c
index 6ab22f29dacd..55d372ce3300 100644
--- i/drivers/md/raid5.c
+++ w/drivers/md/raid5.c
@@ -5717,6 +5717,7 @@ static void make_discard_request(struct mddev
*mddev, struct bio *bi)
raid5_release_stripe(sh);
/* Bail out if REQ_NOWAIT is set */
if (bi->bi_opf & REQ_NOWAIT) {
+ finish_wait(&conf->wait_for_overlap, &w);
bio_wouldblock_error(bi);
return;
}
@@ -5734,6 +5735,7 @@ static void make_discard_request(struct mddev
*mddev, struct bio *bi)
raid5_release_stripe(sh);
/* Bail out if REQ_NOWAIT is set */
if (bi->bi_opf & REQ_NOWAIT) {
+
finish_wait(&conf->wait_for_overlap, &w);
bio_wouldblock_error(bi);
return;
}
@@ -5829,7 +5831,6 @@ static bool raid5_make_request(struct mddev
*mddev, struct bio * bi)
last_sector = bio_end_sector(bi);
bi->bi_next = NULL;
- md_account_bio(mddev, &bi);
/* Bail out if REQ_NOWAIT is set */
if ((bi->bi_opf & REQ_NOWAIT) &&
(conf->reshape_progress != MaxSector) &&
@@ -5837,9 +5838,11 @@ static bool raid5_make_request(struct mddev
*mddev, struct bio * bi)
? (logical_sector > conf->reshape_progress &&
logical_sector <= conf->reshape_safe)
: (logical_sector >= conf->reshape_safe &&
logical_sector
< conf->reshape_progress))) {
bio_wouldblock_error(bi);
+ if (rw == WRITE)
+ md_write_end(mddev);
return true;
}
-
+ md_account_bio(mddev, &bi);
prepare_to_wait(&conf->wait_for_overlap, &w,
TASK_UNINTERRUPTIBLE);
for (; logical_sector < last_sector; logical_sector +=
RAID5_STRIPE_SECTORS(conf)) {
int previous;
============================ 8< ============================
Vishal, please try to trigger all these conditions (including raid1,
raid10) and make sure
they work properly.
For example, I triggered raid5 reshape and used something like the
following to make
sure the logic is triggered:
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 55d372ce3300..e79de48a0027 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5840,6 +5840,11 @@ static bool raid5_make_request(struct mddev
*mddev, struct bio * bi)
bio_wouldblock_error(bi);
if (rw == WRITE)
md_write_end(mddev);
+ {
+ static int count = 0;
+ if (count++ < 10)
+ pr_info("%s REQ_NOWAIT return\n",
__func__);
+ }
return true;
}
md_account_bio(mddev, &bi);
Thanks,
Song
Sure, will try this and verify for raid1/10.
Please also try test raid5 with discard. I haven't tested those two
conditions yet.
Ack.
Do you have suggestion around how to test this. As in use fstrim or
something
to issue discard op to the raid5 array?
I am running into an issue during raid10 reshape. I can see the nowait
code getting triggered during reshape, but it seems like the reshape
operation was stuck as soon as I issued write IO using FIO to the array
during reshape.
FIO also seem stuck i.e no IO went through...
Maybe the following could fix it?
Thanks,
Song
Hmm no luck, still the same issue.
It seems both: iou-wrk thread & md_reshape thread are hung during reshape..
[ 247.889279] task:iou-wrk-9013 state:D stack: 0 pid: 9088 ppid:
8869 flags:0x00004000
[ 247.889282] Call Trace:
[ 247.889284] <TASK>
[ 247.889286] __schedule+0x2d5/0x9b0
[ 247.889292] ? preempt_count_add+0x74/0xc0
[ 247.889295] schedule+0x58/0xd0
[ 247.889298] wait_barrier+0x1ad/0x270 [raid10]
[ 247.889301] ? wait_woken+0x60/0x60
[ 247.889304] regular_request_wait+0x42/0x1e0 [raid10]
[ 247.889306] ? default_wake_function+0x1a/0x30
[ 247.889308] ? autoremove_wake_function+0x12/0x40
[ 247.889310] raid10_write_request+0x85/0x670 [raid10]
[ 247.889312] ? r10bio_pool_alloc+0x26/0x30 [raid10]
[ 247.889314] ? md_write_start+0xa7/0x270
[ 247.889318] raid10_make_request+0xe8/0x170 [raid10]
[ 247.889320] md_handle_request+0x13d/0x1d0
[ 247.889322] ? submit_bio_checks+0x1f6/0x5a0
[ 247.889325] md_submit_bio+0x6d/0xa0
[ 247.889326] __submit_bio+0x94/0x140
[ 247.889327] submit_bio_noacct+0xe1/0x2a0
[ 247.889329] submit_bio+0x48/0x120
[ 247.889330] blkdev_direct_IO+0x19b/0x540
[ 247.889332] ? hctx_unlock+0x17/0x40
[ 247.889335] ? blk_mq_request_issue_directly+0x57/0x80
[ 247.889338] generic_file_direct_write+0x9f/0x190
[ 247.889342] __generic_file_write_iter+0x9d/0x1c0
[ 247.889345] blkdev_write_iter+0xe7/0x160
[ 247.889347] io_write+0x153/0x300
[ 247.889350] ? __this_cpu_preempt_check+0x13/0x20
[ 247.889352] ? __perf_event_task_sched_in+0x81/0x230
[ 247.889355] ? debug_smp_processor_id+0x17/0x20
[ 247.889356] ? __perf_event_task_sched_out+0x77/0x510
[ 247.889359] io_issue_sqe+0x387/0x19c0
[ 247.889361] ? _raw_spin_lock_irqsave+0x1d/0x50
[ 247.889363] ? lock_timer_base+0x72/0xa0
[ 247.889367] io_wq_submit_work+0x67/0x170
[ 247.889369] io_worker_handle_work+0x2b0/0x500
[ 247.889372] io_wqe_worker+0x1ca/0x360
[ 247.889374] ? _raw_spin_unlock+0x1a/0x30
[ 247.889376] ? preempt_count_add+0x74/0xc0
[ 247.889377] ? io_workqueue_create+0x60/0x60
[ 247.889380] ret_from_fork+0x1f/0x30
[ 247.908367] task:md5_reshape state:D stack: 0 pid: 9087
ppid: 2 flags:0x00004000
[ 247.908369] Call Trace:
[ 247.908370] <TASK>
[ 247.908371] __schedule+0x2d5/0x9b0
[ 247.908373] schedule+0x58/0xd0
[ 247.908375] raise_barrier+0xb7/0x170 [raid10]
[ 247.908377] ? wait_woken+0x60/0x60
[ 247.908378] reshape_request+0x1b9/0x920 [raid10]
[ 247.908380] ? __this_cpu_preempt_check+0x13/0x20
[ 247.908382] ? __perf_event_task_sched_in+0x81/0x230
[ 247.908384] raid10_sync_request+0x1073/0x1640 [raid10]
[ 247.908386] ? _raw_spin_unlock+0x1a/0x30
[ 247.908388] ? __switch_to+0x12e/0x430
[ 247.908390] ? __schedule+0x2dd/0x9b0
[ 247.908392] ? blk_flush_plug+0xeb/0x120
[ 247.908393] ? preempt_count_add+0x74/0xc0
[ 247.908394] ? _raw_spin_lock_irqsave+0x1d/0x50
[ 247.908396] md_do_sync.cold+0x3fa/0x97f
[ 247.908399] ? wait_woken+0x60/0x60
[ 247.908401] md_thread+0xae/0x170
[ 247.908402] ? preempt_count_add+0x74/0xc0
[ 247.908403] ? _raw_spin_lock_irqsave+0x1d/0x50
[ 247.908405] kthread+0x177/0x1a0
[ 247.908407] ? md_start_sync+0x60/0x60
[ 247.908408] ? set_kthread_struct+0x40/0x40
[ 247.908410] ret_from_fork+0x1f/0x30
[ 247.908412] </TASK>
diff --git i/drivers/md/raid10.c w/drivers/md/raid10.c
index e2c524d50ec0..291eceaeb26c 100644
--- i/drivers/md/raid10.c
+++ w/drivers/md/raid10.c
@@ -1402,14 +1402,14 @@ static void raid10_write_request(struct mddev
*mddev, struct bio *bio,
: (bio->bi_iter.bi_sector + sectors >
conf->reshape_safe &&
bio->bi_iter.bi_sector < conf->reshape_progress))) {
/* Need to update reshape_position in metadata */
- mddev->reshape_position = conf->reshape_progress;
- set_mask_bits(&mddev->sb_flags, 0,
- BIT(MD_SB_CHANGE_DEVS) |
BIT(MD_SB_CHANGE_PENDING));
- md_wakeup_thread(mddev->thread);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
+ mddev->reshape_position = conf->reshape_progress;
+ set_mask_bits(&mddev->sb_flags, 0,
+ BIT(MD_SB_CHANGE_DEVS) |
BIT(MD_SB_CHANGE_PENDING));
+ md_wakeup_thread(mddev->thread);
raid10_log(conf->mddev, "wait reshape metadata");
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING,
&mddev->sb_flags));
