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| author | Logan Gunthorpe <logang@deltatee.com> | 2022-07-07 13:15:33 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-08-02 17:22:43 -0600 |
| commit | ee1aa06ba3258686452dab2db2a458310a83d07a (patch) | |
| tree | f3f3721c85a27a2423ba84948dd5c29a12faf469 /drivers/md | |
| parent | b9f91d80dec9369294a8df4e4c8850a339a32576 (diff) | |
| download | linux-stable-ee1aa06ba3258686452dab2db2a458310a83d07a.tar.gz linux-stable-ee1aa06ba3258686452dab2db2a458310a83d07a.tar.bz2 linux-stable-ee1aa06ba3258686452dab2db2a458310a83d07a.zip | |
md/raid5: Convert prepare_to_wait() to wait_woken() api
raid5_get_active_stripe() can sleep in various situations and it
is called by make_stripe_request() while inside the
prepare_to_wait()/finish_wait() section. Nested waits like this are
not supported.
This was noticed while making other changes that add different sleeps
to raid5_get_active_stripe() that caused a WARNING with
CONFIG_DEBUG_ATOMIC_SLEEP.
No ill effects have been noticed with the code as is, but theoretically
a nested and here could cause a dead lock so it should be fixed.
To fix this, convert the prepare_to_wait() call to use wake_woken()
which supports nested sleeps.
Link: https://lwn.net/Articles/628628/
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2690298bd92b..6a6f7d969198 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6044,12 +6044,12 @@ out_release: static bool raid5_make_request(struct mddev *mddev, struct bio * bi) { + DEFINE_WAIT_FUNC(wait, woken_wake_function); struct r5conf *conf = mddev->private; sector_t logical_sector; struct stripe_request_ctx ctx = {}; const int rw = bio_data_dir(bi); enum stripe_result res; - DEFINE_WAIT(w); int s, stripe_cnt; if (unlikely(bi->bi_opf & REQ_PREFLUSH)) { @@ -6112,7 +6112,8 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) return true; } md_account_bio(mddev, &bi); - prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); + + add_wait_queue(&conf->wait_for_overlap, &wait); while (1) { res = make_stripe_request(mddev, conf, &ctx, logical_sector, bi); @@ -6135,9 +6136,8 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) ctx.batch_last = NULL; } - schedule(); - prepare_to_wait(&conf->wait_for_overlap, &w, - TASK_UNINTERRUPTIBLE); + wait_woken(&wait, TASK_UNINTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT); continue; } @@ -6148,8 +6148,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) logical_sector = ctx.first_sector + (s << RAID5_STRIPE_SHIFT(conf)); } - - finish_wait(&conf->wait_for_overlap, &w); + remove_wait_queue(&conf->wait_for_overlap, &wait); if (ctx.batch_last) raid5_release_stripe(ctx.batch_last); |