5.15-stable patches

added patches:
	block-mq-deadline-fix-dd_finish_request-for-zoned-devices.patch

diff --git a/queue-5.15/block-mq-deadline-fix-dd_finish_request-for-zoned-devices.patch b/queue-5.15/block-mq-deadline-fix-dd_finish_request-for-zoned-devices.patch
new file mode 100644 (file)
index 0000000..fa7ad14
--- /dev/null
+++ b/queue-5.15/block-mq-deadline-fix-dd_finish_request-for-zoned-devices.patch
@@ -0,0 +1,82 @@
+From 2820e5d0820ac4daedff1272616a53d9c7682fd2 Mon Sep 17 00:00:00 2001
+From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Date: Thu, 24 Nov 2022 11:12:07 +0900
+Subject: block: mq-deadline: Fix dd_finish_request() for zoned devices
+
+From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+
+commit 2820e5d0820ac4daedff1272616a53d9c7682fd2 upstream.
+
+dd_finish_request() tests if the per prio fifo_list is not empty to
+determine if request dispatching must be restarted for handling blocked
+write requests to zoned devices with a call to
+blk_mq_sched_mark_restart_hctx(). While simple, this implementation has
+2 problems:
+
+1) Only the priority level of the completed request is considered.
+   However, writes to a zone may be blocked due to other writes to the
+   same zone using a different priority level. While this is unlikely to
+   happen in practice, as writing a zone with different IO priorirites
+   does not make sense, nothing in the code prevents this from
+   happening.
+2) The use of list_empty() is dangerous as dd_finish_request() does not
+   take dd->lock and may run concurrently with the insert and dispatch
+   code.
+
+Fix these 2 problems by testing the write fifo list of all priority
+levels using the new helper dd_has_write_work(), and by testing each
+fifo list using list_empty_careful().
+
+Fixes: c807ab520fc3 ("block/mq-deadline: Add I/O priority support")
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
+Link: https://lore.kernel.org/r/20221124021208.242541-2-damien.lemoal@opensource.wdc.com
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ block/mq-deadline.c |   18 +++++++++++++++---
+ 1 file changed, 15 insertions(+), 3 deletions(-)
+
+--- a/block/mq-deadline.c
++++ b/block/mq-deadline.c
+@@ -791,6 +791,18 @@ static void dd_prepare_request(struct re
+       rq->elv.priv[0] = NULL;
+ }
+ 
++static bool dd_has_write_work(struct blk_mq_hw_ctx *hctx)
++{
++      struct deadline_data *dd = hctx->queue->elevator->elevator_data;
++      enum dd_prio p;
++
++      for (p = 0; p <= DD_PRIO_MAX; p++)
++              if (!list_empty_careful(&dd->per_prio[p].fifo_list[DD_WRITE]))
++                      return true;
++
++      return false;
++}
++
+ /*
+  * Callback from inside blk_mq_free_request().
+  *
+@@ -813,7 +825,6 @@ static void dd_finish_request(struct req
+       struct deadline_data *dd = q->elevator->elevator_data;
+       const u8 ioprio_class = dd_rq_ioclass(rq);
+       const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+-      struct dd_per_prio *per_prio = &dd->per_prio[prio];
+ 
+       /*
+        * The block layer core may call dd_finish_request() without having
+@@ -829,9 +840,10 @@ static void dd_finish_request(struct req
+ 
+               spin_lock_irqsave(&dd->zone_lock, flags);
+               blk_req_zone_write_unlock(rq);
+-              if (!list_empty(&per_prio->fifo_list[DD_WRITE]))
+-                      blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
+               spin_unlock_irqrestore(&dd->zone_lock, flags);
++
++              if (dd_has_write_work(rq->mq_hctx))
++                      blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
+       }
+ }
+ 

diff --git a/queue-5.15/series b/queue-5.15/series
index f12f4a2433b7e93daa2bf5fb451afb6ccdbf5b67..9b47cb47d2f581b6f843ade3b41e45451f510b23 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -162,3 +162,4 @@ ext4-avoid-unaccounted-block-allocation-when-expanding-inode.patch
 ext4-allocate-extended-attribute-value-in-vmalloc-area.patch
 drm-amdgpu-handle-polaris10-11-overlap-asics-v2.patch
 drm-amdgpu-make-display-pinning-more-flexible-v2.patch
+block-mq-deadline-fix-dd_finish_request-for-zoned-devices.patch