From: Damien Le Moal <dlemoal@xxxxxxxxxx>
commit 5eb3317aa5a2ffe4574ab1a12cf9bc9447ca26c0 upstream.
There are currently any issuer of REQ_OP_ZONE_RESET and
REQ_OP_ZONE_FINISH operations that set REQ_NOWAIT. However, as we cannot
handle this flag correctly due to the potential request allocation
failure that may happen in blk_mq_submit_bio() after blk_zone_plug_bio()
has handled the zone write plug write pointer updates for the targeted
zones, modify blk_zone_wplug_handle_reset_or_finish() to warn if this
flag is set and ignore it.
Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241209122357.47838-3-dlemoal@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk-zoned.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -704,6 +704,15 @@ static bool blk_zone_wplug_handle_reset_
}
/*
+ * No-wait reset or finish BIOs do not make much sense as the callers
+ * issue these as blocking operations in most cases. To avoid issues
+ * the BIO execution potentially failing with BLK_STS_AGAIN, warn about
+ * REQ_NOWAIT being set and ignore that flag.
+ */
+ if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT))
+ bio->bi_opf &= ~REQ_NOWAIT;
+
+ /*
* If we have a zone write plug, set its write pointer offset to 0
* (reset case) or to the zone size (finish case). This will abort all
* BIOs plugged for the target zone. It is fine as resetting or
Patches currently in stable-queue which might be from dlemoal@xxxxxxxxxx are
queue-6.12/block-switch-to-using-refcount_t-for-zone-write-plugs.patch
queue-6.12/block-ignore-req_nowait-for-zone-reset-and-zone-finish-operations.patch
queue-6.12/block-use-a-zone-write-plug-bio-work-for-req_nowait-bios.patch
queue-6.12/block-prevent-potential-deadlocks-in-zone-write-plug-error-recovery.patch
queue-6.12/dm-fix-dm-zoned-reclaim-zone-write-pointer-alignment.patch
