* [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
@ 2020-08-18 17:39 Ritika Srivastava
2020-08-18 19:43 ` Christoph Hellwig
0 siblings, 1 reply; 4+ messages in thread
From: Ritika Srivastava @ 2020-08-18 17:39 UTC (permalink / raw)
To: linux-block, axboe; +Cc: martin.petersen, hch, ritika.srivastava
If WRITE_ZERO/WRITE_SAME operation is not supported by the storage,
blk_cloned_rq_check_limits() will return IO error which will cause
device-mapper to fail the paths.
Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP.
BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the
paths.
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
Changelog:
v4: Explain the window of error in the comments.
Add reviewed-by tag from Martin
v3: Formatting changes and subject updated from previous version
-block: return BLK_STS_NOTSUPP if operation is not supported
v2: Document scenario and SCSI error encountered in a comment in
blk_cloned_rq_check_limits().
---
block/blk-core.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index d241ab8..43401d3 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1223,10 +1223,24 @@ blk_qc_t submit_bio(struct bio *bio)
static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
struct request *rq)
{
- if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) {
+ unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
+
+ if (blk_rq_sectors(rq) > max_sectors) {
+ /*
+ * SCSI device does not have a good way to return if
+ * Write Same/Zero is actually supported. If a device rejects
+ * a non-read/write command (discard, write same,etc.) the
+ * low-level device driver will set the relevant queue limit to
+ * 0 to prevent blk-lib from issuing more of the offending
+ * operations. Commands queued prior to the queue limit being
+ * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
+ * errors being propagated to upper layers.
+ */
+ if (max_sectors == 0)
+ return BLK_STS_NOTSUPP;
+
printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
- __func__, blk_rq_sectors(rq),
- blk_queue_get_max_sectors(q, req_op(rq)));
+ __func__, blk_rq_sectors(rq), max_sectors);
return BLK_STS_IOERR;
}
@@ -1253,8 +1267,11 @@ static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
*/
blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
{
- if (blk_cloned_rq_check_limits(q, rq))
- return BLK_STS_IOERR;
+ blk_status_t ret;
+
+ ret = blk_cloned_rq_check_limits(q, rq);
+ if (ret != BLK_STS_OK)
+ return ret;
if (rq->rq_disk &&
should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
2020-08-18 17:39 [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits Ritika Srivastava
@ 2020-08-18 19:43 ` Christoph Hellwig
2020-08-26 17:03 ` Ritika Srivastava
0 siblings, 1 reply; 4+ messages in thread
From: Christoph Hellwig @ 2020-08-18 19:43 UTC (permalink / raw)
To: Ritika Srivastava; +Cc: linux-block, axboe, martin.petersen, hch
On Tue, Aug 18, 2020 at 10:39:40AM -0700, Ritika Srivastava wrote:
> If WRITE_ZERO/WRITE_SAME operation is not supported by the storage,
> blk_cloned_rq_check_limits() will return IO error which will cause
> device-mapper to fail the paths.
>
> Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP.
> BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the
> paths.
>
> Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
> Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
2020-08-18 19:43 ` Christoph Hellwig
@ 2020-08-26 17:03 ` Ritika Srivastava
0 siblings, 0 replies; 4+ messages in thread
From: Ritika Srivastava @ 2020-08-26 17:03 UTC (permalink / raw)
To: axboe; +Cc: linux-block, Christoph Hellwig
Hi Jens,
Can the following patches please be applied.
[PATCH 1/2] block: Return blk_status_t instead of errno codes
[PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
Thanks,
Ritika
> On Aug 18, 2020, at 12:43 PM, Christoph Hellwig <hch@infradead.org> wrote:
>
> On Tue, Aug 18, 2020 at 10:39:40AM -0700, Ritika Srivastava wrote:
>> If WRITE_ZERO/WRITE_SAME operation is not supported by the storage,
>> blk_cloned_rq_check_limits() will return IO error which will cause
>> device-mapper to fail the paths.
>>
>> Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP.
>> BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the
>> paths.
>>
>> Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
>> Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
>> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
>
> Looks good,
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits
2020-09-01 20:17 Return BLK_STS_NOTSUPP and blk_status_t from blk_cloned_rq_check_limits() Ritika Srivastava
@ 2020-09-01 20:17 ` Ritika Srivastava
0 siblings, 0 replies; 4+ messages in thread
From: Ritika Srivastava @ 2020-09-01 20:17 UTC (permalink / raw)
To: axboe; +Cc: linux-block, ritika.srivastava
If WRITE_ZERO/WRITE_SAME operation is not supported by the storage,
blk_cloned_rq_check_limits() will return IO error which will cause
device-mapper to fail the paths.
Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP.
BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the
paths.
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
Changelog:
v4: Explain the window of error in the comments.
Add reviewed-by tag from Martin
v3: Formatting changes and subject updated from previous version
-block: return BLK_STS_NOTSUPP if operation is not supported
v2: Document scenario and SCSI error encountered in a comment in
blk_cloned_rq_check_limits().
---
block/blk-core.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 4c1af34..d857344 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1147,10 +1147,24 @@ blk_qc_t submit_bio(struct bio *bio)
static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
struct request *rq)
{
- if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) {
+ unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
+
+ if (blk_rq_sectors(rq) > max_sectors) {
+ /*
+ * SCSI device does not have a good way to return if
+ * Write Same/Zero is actually supported. If a device rejects
+ * a non-read/write command (discard, write same,etc.) the
+ * low-level device driver will set the relevant queue limit to
+ * 0 to prevent blk-lib from issuing more of the offending
+ * operations. Commands queued prior to the queue limit being
+ * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
+ * errors being propagated to upper layers.
+ */
+ if (max_sectors == 0)
+ return BLK_STS_NOTSUPP;
+
printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
- __func__, blk_rq_sectors(rq),
- blk_queue_get_max_sectors(q, req_op(rq)));
+ __func__, blk_rq_sectors(rq), max_sectors);
return BLK_STS_IOERR;
}
@@ -1177,8 +1191,11 @@ static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
*/
blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
{
- if (blk_cloned_rq_check_limits(q, rq))
- return BLK_STS_IOERR;
+ blk_status_t ret;
+
+ ret = blk_cloned_rq_check_limits(q, rq);
+ if (ret != BLK_STS_OK)
+ return ret;
if (rq->rq_disk &&
should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-09-01 20:33 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-18 17:39 [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits Ritika Srivastava
2020-08-18 19:43 ` Christoph Hellwig
2020-08-26 17:03 ` Ritika Srivastava
2020-09-01 20:17 Return BLK_STS_NOTSUPP and blk_status_t from blk_cloned_rq_check_limits() Ritika Srivastava
2020-09-01 20:17 ` [PATCH v4 2/2] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits Ritika Srivastava
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).