* RE: [PATCH v4 4/8] nvme-rdma: use rdma connection reject helper functions
From: Steve Wise @ 2016-10-26 19:39 UTC (permalink / raw)
To: 'Bart Van Assche', dledford-H+wXaHxf7aLQT0dZR+AlfA,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
sagi-NQWnxTmZq1alnMjI0IkVqw, hch-jcswGhMUV9g, axboe-b10kYP2dOMg,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA
In-Reply-To: <62db5521-9c15-146b-9057-2a22658fa210-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
>
> If you have to resend this patch series please address these comments.
>
> Thanks,
>
> Bart.
Hey Bart, shall I add a reviewed-by tag from you for this patch?
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^ permalink raw reply
* [PATCH v5 0/8] connect reject event helpers
From: Steve Wise @ 2016-10-26 19:40 UTC (permalink / raw)
To: dledford-H+wXaHxf7aLQT0dZR+AlfA,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA,
bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
sagi-NQWnxTmZq1alnMjI0IkVqw, hch-jcswGhMUV9g, axboe-b10kYP2dOMg,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA
While reviewing:
http://lists.infradead.org/pipermail/linux-nvme/2016-October/006681.html
I decided to propose transport-agnostic helper functions to better
handle connection reject event information. Included are patches
for nvme/fabrics, iser, and rds to utilize the new helpers.
Doug, this series applies on top of v4.9-rc2 as well as sagi's nvmf-4.9-rc
branch as of today. The series should be targeted for 4.10.
Changes since v4:
- fixed typos in the review-by tags for Sagi
- make rej_data a const pointer in nvme_rdma_conn_rejected()
- balanced braces for if/then/else in nvme_rdma_conn_rejected()
Changes since v3:
- added reviewed-by/acked-by tags
- positive logic in reject_msg helpers
- cleaned up reject message strings
- added patches to use helpers in isert and nvmet_rdma
- fixed zero-day build warning
Changes since v2:
- reworked ibcm/iwcm_reject_msg() as per Christoph's recommendation
- use ibcm_ and iwcm_ prefix instead of ib_ and iw_ for reject_msg funcs
- change rdma_consumer_reject() to rdma_is_consumer_reject()
- add rdma_consumer_reject_data() helper function to return private
data/len
- use new helpers in nvme_rdma, ib_iser, and rdma_rds
- in nvme_rdma, add strings for nvme_rdma_cm_status values
---
Steve Wise (8):
rdma_cm: add rdma_reject_msg() helper function
rdma_cm: add rdma_is_consumer_reject() helper function
rdma_cm: add rdma_consumer_reject_data helper function
nvme-rdma: use rdma connection reject helper functions
ib_iser: log the connection reject message
rds_rdma: log the connection reject message
ib_isert: log the connection reject message
nvmet_rdma: log the connection reject message
drivers/infiniband/core/cm.c | 48 ++++++++++++++++++++++++++++++++
drivers/infiniband/core/cma.c | 43 ++++++++++++++++++++++++++++
drivers/infiniband/core/iwcm.c | 21 ++++++++++++++
drivers/infiniband/ulp/iser/iser_verbs.c | 5 +++-
drivers/infiniband/ulp/isert/ib_isert.c | 2 ++
drivers/nvme/host/rdma.c | 42 ++++++++++++++++++++++++----
drivers/nvme/target/rdma.c | 3 ++
include/rdma/ib_cm.h | 6 ++++
include/rdma/iw_cm.h | 6 ++++
include/rdma/rdma_cm.h | 25 +++++++++++++++++
net/rds/rdma_transport.c | 5 +++-
11 files changed, 198 insertions(+), 8 deletions(-)
--
2.7.0
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^ permalink raw reply
* RE: [PATCH v4 4/8] nvme-rdma: use rdma connection reject helper functions
From: Steve Wise @ 2016-10-26 19:51 UTC (permalink / raw)
To: 'Bart Van Assche', dledford-H+wXaHxf7aLQT0dZR+AlfA,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
sagi-NQWnxTmZq1alnMjI0IkVqw, hch-jcswGhMUV9g, axboe-b10kYP2dOMg,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA
In-Reply-To: <07d201d22fc0$9c189a10$d449ce30$@opengridcomputing.com>
> Hey Bart, shall I add a reviewed-by tag from you for this patch?
>
I went ahead and sent out v5...
Steve
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^ permalink raw reply
* Re: [PATCH v5 1/8] rdma_cm: add rdma_reject_msg() helper function
From: Bart Van Assche @ 2016-10-26 20:02 UTC (permalink / raw)
To: swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org,
dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: hch-jcswGhMUV9g@public.gmane.org,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
axboe-b10kYP2dOMg@public.gmane.org,
sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org
In-Reply-To: <1a760877f98e537b236f443fc2a6f4e9ec06c356.1477510827.git.swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
On Wed, 2016-10-26 at 12:36 -0700, Steve Wise wrote:
> rdma_reject_msg() returns a pointer to a string message associated
> with the transport reject reason codes.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
^ permalink raw reply
* Re: [PATCH v5 2/8] rdma_cm: add rdma_is_consumer_reject() helper function
From: Bart Van Assche @ 2016-10-26 20:02 UTC (permalink / raw)
To: swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org,
dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: hch-jcswGhMUV9g@public.gmane.org,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
axboe-b10kYP2dOMg@public.gmane.org,
sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org
In-Reply-To: <43be5a7d10e325a5c0a735539c160355029d08e2.1477510827.git.swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
On Wed, 2016-10-26 at 12:36 -0700, Steve Wise wrote:
> Return true if the peer consumer application rejected the
> connection attempt.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
^ permalink raw reply
* Re: [PATCH v5 3/8] rdma_cm: add rdma_consumer_reject_data helper function
From: Bart Van Assche @ 2016-10-26 20:03 UTC (permalink / raw)
To: swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org,
dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: hch-jcswGhMUV9g@public.gmane.org,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
axboe-b10kYP2dOMg@public.gmane.org,
sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org
In-Reply-To: <31b1e8fba4b934b5df421191b4788a5c25788961.1477510827.git.swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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On Wed, 2016-10-26 at 12:36 -0700, Steve Wise wrote:
> rdma_consumer_reject_data() will return the private data pointer
> and length if any is available.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>N‹§²æìr¸›yúèšØb²X¬¶Ç§vØ^–)Þº{.nÇ+‰·¥Š{±ÙšŠ{ayº\x1dʇڙë,j\a¢f£¢·hš‹»öì\x17/oSc¾™Ú³9˜uÀ¦æå‰È&jw¨®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿïêäz¹Þ–Šàþf£¢·hšˆ§~ˆmš
^ permalink raw reply
* Re: [PATCH v5 4/8] nvme-rdma: use rdma connection reject helper functions
From: Bart Van Assche @ 2016-10-26 20:04 UTC (permalink / raw)
To: swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org,
dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: hch-jcswGhMUV9g@public.gmane.org,
santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
axboe-b10kYP2dOMg@public.gmane.org,
sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org
In-Reply-To: <b61e9a20572b3afb4ebf62a0a1613097311e7c92.1477510827.git.swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 295 bytes --]
On Wed, 2016-10-26 at 12:36 -0700, Steve Wise wrote:
> Also add nvme cm status strings and use them.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>N‹§²æìr¸›yúèšØb²X¬¶Ç§vØ^–)Þº{.nÇ+‰·¥Š{±ÙšŠ{ayº\x1dʇڙë,j\a¢f£¢·hš‹»öì\x17/oSc¾™Ú³9˜uÀ¦æå‰È&jw¨®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿïêäz¹Þ–Šàþf£¢·hšˆ§~ˆmš
^ permalink raw reply
* [PATCH v4 0/12] Fix race conditions related to stopping block layer queues
From: Bart Van Assche @ 2016-10-26 22:49 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lin,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
Hello Jens,
Multiple block drivers need the functionality to stop a request queue
and to wait until all ongoing request_fn() / queue_rq() calls have
finished without waiting until all outstanding requests have finished.
Hence this patch series that introduces the blk_mq_quiesce_queue()
function. The dm-mq, SRP and NVMe patches in this patch series are three
examples of where these functions are useful. These patches have been
tested on top of kernel v4.9-rc1. The following tests have been run to
verify this patch series:
- Mike's mptest suite that stress-tests dm-multipath.
- My own srp-test suite that stress-tests SRP on top of dm-multipath.
- fio on top of the NVMeOF host driver that was connected to the NVMeOF
target driver on the same host.
- Laurence verified the previous version (v3) of this patch series by
running it through the Red Hat SRP and NVMe test suites.
The changes compared to the third version of this patch series are:
- Left out the dm changes from the patch that introduces
blk_mq_hctx_stopped() because a later patch deletes the changed code
from the dm core.
- Moved the blk_mq_hctx_stopped() declaration from a public to a
private block layer header file.
- Added a new patch that moves more code into
blk_mq_direct_issue_request(). This patch avoids that a new function
has to be introduced to avoid code duplication.
- Explained the implemented algorithm in the patch that introduces
blk_mq_quiesce_queue() in the description of the patch that
introduces this function.
- Added "select SRCU" to the patch that introduces
blk_mq_quiesce_queue() to avoid build failures.
- Documented the shost argument in the scsi_wait_for_queuecommand()
kerneldoc header.
- Fixed an unintended behavior change in the last patch of this series.
Changes between v3 and v2:
- Changed the order of the patches in this patch series.
- Added several new patches: a patch that avoids that .queue_rq() gets
invoked from the direct submission path if a queue has been stopped
and also a patch that introduces the helper function
blk_mq_hctx_stopped().
- blk_mq_quiesce_queue() has been reworked (thanks to Ming Lin and Sagi
for their feedback).
- A bool 'kick' argument has been added to blk_mq_requeue_request().
- As proposed by Christoph, the code that waits for queuecommand() has
been moved from the SRP transport driver to the SCSI core.
Changes between v2 and v1:
- Dropped the non-blk-mq changes from this patch series.
- Added support for harware queues with BLK_MQ_F_BLOCKING set.
- Added a call stack to the description of the dm race fix patch.
- Dropped the non-scsi-mq changes from the SRP patch.
- Added a patch that introduces blk_mq_queue_stopped() in the dm driver.
The individual patches in this series are:
0001-blk-mq-Do-not-invoke-.queue_rq-for-a-stopped-queue.patch
0002-blk-mq-Introduce-blk_mq_hctx_stopped.patch
0003-blk-mq-Introduce-blk_mq_queue_stopped.patch
0004-blk-mq-Move-more-code-into-blk_mq_direct_issue_reque.patch
0005-blk-mq-Introduce-blk_mq_quiesce_queue.patch
0006-blk-mq-Add-a-kick_requeue_list-argument-to-blk_mq_re.patch
0007-dm-Use-BLK_MQ_S_STOPPED-instead-of-QUEUE_FLAG_STOPPE.patch
0008-dm-Fix-a-race-condition-related-to-stopping-and-star.patch
0009-SRP-transport-Move-queuecommand-wait-code-to-SCSI-co.patch
0010-SRP-transport-scsi-mq-Wait-for-.queue_rq-if-necessar.patch
0011-nvme-Use-BLK_MQ_S_STOPPED-instead-of-QUEUE_FLAG_STOP.patch
0012-nvme-Fix-a-race-condition-related-to-stopping-queues.patch
Thanks,
Bart.
^ permalink raw reply
* [PATCH 01/12] blk-mq: Do not invoke .queue_rq() for a stopped queue
From: Bart Van Assche @ 2016-10-26 22:50 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lin,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
The meaning of the BLK_MQ_S_STOPPED flag is "do not call
.queue_rq()". Hence modify blk_mq_make_request() such that requests
are queued instead of issued if a queue has been stopped.
Reported-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: <stable@vger.kernel.org>
---
block/blk-mq.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ddc2eed..b5dcafb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1332,9 +1332,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_mq_put_ctx(data.ctx);
if (!old_rq)
goto done;
- if (!blk_mq_direct_issue_request(old_rq, &cookie))
- goto done;
- blk_mq_insert_request(old_rq, false, true, true);
+ if (test_bit(BLK_MQ_S_STOPPED, &data.hctx->state) ||
+ blk_mq_direct_issue_request(old_rq, &cookie) != 0)
+ blk_mq_insert_request(old_rq, false, true, true);
goto done;
}
--
2.10.1
^ permalink raw reply related
* [PATCH 02/12] blk-mq: Introduce blk_mq_hctx_stopped()
From: Bart Van Assche @ 2016-10-26 22:51 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Multiple functions test the BLK_MQ_S_STOPPED bit so introduce
a helper function that performs this test.
Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>
Cc: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Cc: Johannes Thumshirn <jthumshirn-l3A5Bk7waGM@public.gmane.org>
---
block/blk-mq.c | 12 ++++++------
block/blk-mq.h | 5 +++++
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b5dcafb..b52b3a6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -787,7 +787,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
struct list_head *dptr;
int queued;
- if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
+ if (unlikely(blk_mq_hctx_stopped(hctx)))
return;
WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
@@ -912,8 +912,8 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
{
- if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
- !blk_mq_hw_queue_mapped(hctx)))
+ if (unlikely(blk_mq_hctx_stopped(hctx) ||
+ !blk_mq_hw_queue_mapped(hctx)))
return;
if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
@@ -938,7 +938,7 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async)
queue_for_each_hw_ctx(q, hctx, i) {
if ((!blk_mq_hctx_has_pending(hctx) &&
list_empty_careful(&hctx->dispatch)) ||
- test_bit(BLK_MQ_S_STOPPED, &hctx->state))
+ blk_mq_hctx_stopped(hctx))
continue;
blk_mq_run_hw_queue(hctx, async);
@@ -988,7 +988,7 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
int i;
queue_for_each_hw_ctx(q, hctx, i) {
- if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
+ if (!blk_mq_hctx_stopped(hctx))
continue;
clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
@@ -1332,7 +1332,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_mq_put_ctx(data.ctx);
if (!old_rq)
goto done;
- if (test_bit(BLK_MQ_S_STOPPED, &data.hctx->state) ||
+ if (blk_mq_hctx_stopped(data.hctx) ||
blk_mq_direct_issue_request(old_rq, &cookie) != 0)
blk_mq_insert_request(old_rq, false, true, true);
goto done;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index e5d2524..ac772da 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -100,6 +100,11 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
data->hctx = hctx;
}
+static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
+{
+ return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
+}
+
static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
{
return hctx->nr_ctx && hctx->tags;
--
2.10.1
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^ permalink raw reply related
* [PATCH 03/12] blk-mq: Introduce blk_mq_queue_stopped()
From: Bart Van Assche @ 2016-10-26 22:52 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
The function blk_queue_stopped() allows to test whether or not a
traditional request queue has been stopped. Introduce a helper
function that allows block drivers to query easily whether or not
one or more hardware contexts of a blk-mq queue have been stopped.
Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Reviewed-by: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>
Reviewed-by: Johannes Thumshirn <jthumshirn-l3A5Bk7waGM@public.gmane.org>
Reviewed-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
block/blk-mq.c | 20 ++++++++++++++++++++
include/linux/blk-mq.h | 1 +
2 files changed, 21 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b52b3a6..4643fa8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -946,6 +946,26 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async)
}
EXPORT_SYMBOL(blk_mq_run_hw_queues);
+/**
+ * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped
+ * @q: request queue.
+ *
+ * The caller is responsible for serializing this function against
+ * blk_mq_{start,stop}_hw_queue().
+ */
+bool blk_mq_queue_stopped(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ if (blk_mq_hctx_stopped(hctx))
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(blk_mq_queue_stopped);
+
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
{
cancel_work(&hctx->run_work);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 535ab2e..aa93000 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -223,6 +223,7 @@ void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs
void blk_mq_abort_requeue_list(struct request_queue *q);
void blk_mq_complete_request(struct request *rq, int error);
+bool blk_mq_queue_stopped(struct request_queue *q);
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_stop_hw_queues(struct request_queue *q);
--
2.10.1
--
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^ permalink raw reply related
* [PATCH 04/12] blk-mq: Move more code into blk_mq_direct_issue_request()
From: Bart Van Assche @ 2016-10-26 22:52 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
Move the "hctx stopped" test and the insert request calls into
blk_mq_direct_issue_request(). Rename that function into
blk_mq_try_issue_directly() to reflect its new semantics. Pass
the hctx pointer to that function instead of looking it up a
second time. These changes avoid that code has to be duplicated
in the next patch.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
block/blk-mq.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4643fa8..0cf21c2 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1243,11 +1243,11 @@ static struct request *blk_mq_map_request(struct request_queue *q,
return rq;
}
-static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
+static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, blk_qc_t *cookie)
{
int ret;
struct request_queue *q = rq->q;
- struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
struct blk_mq_queue_data bd = {
.rq = rq,
.list = NULL,
@@ -1255,6 +1255,9 @@ static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
};
blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
+ if (blk_mq_hctx_stopped(hctx))
+ goto insert;
+
/*
* For OK queue, we are done. For error, kill it. Any other
* error (busy), just add it to our list as we previously
@@ -1263,7 +1266,7 @@ static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
ret = q->mq_ops->queue_rq(hctx, &bd);
if (ret == BLK_MQ_RQ_QUEUE_OK) {
*cookie = new_cookie;
- return 0;
+ return;
}
__blk_mq_requeue_request(rq);
@@ -1272,10 +1275,11 @@ static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
*cookie = BLK_QC_T_NONE;
rq->errors = -EIO;
blk_mq_end_request(rq, rq->errors);
- return 0;
+ return;
}
- return -1;
+insert:
+ blk_mq_insert_request(rq, false, true, true);
}
/*
@@ -1352,9 +1356,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_mq_put_ctx(data.ctx);
if (!old_rq)
goto done;
- if (blk_mq_hctx_stopped(data.hctx) ||
- blk_mq_direct_issue_request(old_rq, &cookie) != 0)
- blk_mq_insert_request(old_rq, false, true, true);
+ blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
goto done;
}
--
2.10.1
^ permalink raw reply related
* [PATCH 05/12] blk-mq: Introduce blk_mq_quiesce_queue()
From: Bart Van Assche @ 2016-10-26 22:53 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations
have finished. This function does *not* wait until all outstanding
requests have finished (this means invocation of request.end_io()).
The algorithm used by blk_mq_quiesce_queue() is as follows:
* Hold either an RCU read lock or an SRCU read lock around
.queue_rq() calls. The former is used if .queue_rq() does not
block and the latter if .queue_rq() may block.
* blk_mq_quiesce_queue() calls synchronize_srcu() or
synchronize_rcu() to wait for .queue_rq() invocations that
started before blk_mq_quiesce_queue() was called.
* The blk_mq_hctx_stopped() calls that control whether or not
.queue_rq() will be called are called with the (S)RCU read lock
held. This is necessary to avoid race conditions against
the "blk_mq_stop_hw_queues(q); blk_mq_quiesce_queue(q);"
sequence from another thread.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
block/Kconfig | 1 +
block/blk-mq.c | 69 +++++++++++++++++++++++++++++++++++++++++++++-----
include/linux/blk-mq.h | 3 +++
include/linux/blkdev.h | 1 +
4 files changed, 67 insertions(+), 7 deletions(-)
diff --git a/block/Kconfig b/block/Kconfig
index 1d4d624..0562ef9 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -5,6 +5,7 @@ menuconfig BLOCK
bool "Enable the block layer" if EXPERT
default y
select SBITMAP
+ select SRCU
help
Provide block layer support for the kernel.
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0cf21c2..4945437 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -115,6 +115,31 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
}
EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
+/**
+ * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished
+ * @q: request queue.
+ *
+ * Note: this function does not prevent that the struct request end_io()
+ * callback function is invoked. Additionally, it is not prevented that
+ * new queue_rq() calls occur unless the queue has been stopped first.
+ */
+void blk_mq_quiesce_queue(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+ bool rcu = false;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ synchronize_srcu(&hctx->queue_rq_srcu);
+ else
+ rcu = true;
+ }
+ if (rcu)
+ synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
+
void blk_mq_wake_waiters(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
@@ -778,7 +803,7 @@ static inline unsigned int queued_to_index(unsigned int queued)
* of IO. In particular, we'd like FIFO behaviour on handling existing
* items on the hctx->dispatch list. Ignore that for now.
*/
-static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
+static void blk_mq_process_rq_list(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
struct request *rq;
@@ -790,9 +815,6 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
if (unlikely(blk_mq_hctx_stopped(hctx)))
return;
- WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
- cpu_online(hctx->next_cpu));
-
hctx->run++;
/*
@@ -883,6 +905,24 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
}
}
+static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
+{
+ int srcu_idx;
+
+ WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
+ cpu_online(hctx->next_cpu));
+
+ if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
+ rcu_read_lock();
+ blk_mq_process_rq_list(hctx);
+ rcu_read_unlock();
+ } else {
+ srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
+ blk_mq_process_rq_list(hctx);
+ srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
+ }
+}
+
/*
* It'd be great if the workqueue API had a way to pass
* in a mask and had some smarts for more clever placement.
@@ -1293,7 +1333,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
struct blk_map_ctx data;
struct request *rq;
- unsigned int request_count = 0;
+ unsigned int request_count = 0, srcu_idx;
struct blk_plug *plug;
struct request *same_queue_rq = NULL;
blk_qc_t cookie;
@@ -1336,7 +1376,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_mq_bio_to_request(rq, bio);
/*
- * We do limited pluging. If the bio can be merged, do that.
+ * We do limited plugging. If the bio can be merged, do that.
* Otherwise the existing request in the plug list will be
* issued. So the plug list will have one request at most
*/
@@ -1356,7 +1396,16 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_mq_put_ctx(data.ctx);
if (!old_rq)
goto done;
- blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
+
+ if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) {
+ rcu_read_lock();
+ blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
+ rcu_read_unlock();
+ } else {
+ srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu);
+ blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
+ srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx);
+ }
goto done;
}
@@ -1635,6 +1684,9 @@ static void blk_mq_exit_hctx(struct request_queue *q,
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, hctx_idx);
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ cleanup_srcu_struct(&hctx->queue_rq_srcu);
+
blk_mq_remove_cpuhp(hctx);
blk_free_flush_queue(hctx->fq);
sbitmap_free(&hctx->ctx_map);
@@ -1715,6 +1767,9 @@ static int blk_mq_init_hctx(struct request_queue *q,
flush_start_tag + hctx_idx, node))
goto free_fq;
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ init_srcu_struct(&hctx->queue_rq_srcu);
+
return 0;
free_fq:
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index aa93000..61be48b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -3,6 +3,7 @@
#include <linux/blkdev.h>
#include <linux/sbitmap.h>
+#include <linux/srcu.h>
struct blk_mq_tags;
struct blk_flush_queue;
@@ -35,6 +36,8 @@ struct blk_mq_hw_ctx {
struct blk_mq_tags *tags;
+ struct srcu_struct queue_rq_srcu;
+
unsigned long queued;
unsigned long run;
#define BLK_MQ_MAX_DISPATCH_ORDER 7
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c47c358..8259d87 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -824,6 +824,7 @@ extern void __blk_run_queue(struct request_queue *q);
extern void __blk_run_queue_uncond(struct request_queue *q);
extern void blk_run_queue(struct request_queue *);
extern void blk_run_queue_async(struct request_queue *q);
+extern void blk_mq_quiesce_queue(struct request_queue *q);
extern int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long,
gfp_t);
--
2.10.1
^ permalink raw reply related
* [PATCH 06/12] blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()
From: Bart Van Assche @ 2016-10-26 22:53 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
are followed by kicking the requeue list. Hence add an argument to
these two functions that allows to kick the requeue list. This was
proposed by Christoph Hellwig.
Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>
Cc: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Cc: Johannes Thumshirn <jthumshirn-l3A5Bk7waGM@public.gmane.org>
---
block/blk-flush.c | 5 +----
block/blk-mq.c | 10 +++++++---
drivers/block/xen-blkfront.c | 2 +-
drivers/md/dm-rq.c | 2 +-
drivers/nvme/host/core.c | 2 +-
drivers/scsi/scsi_lib.c | 4 +---
include/linux/blk-mq.h | 5 +++--
7 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 6a14b68..a834aed 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -134,10 +134,7 @@ static void blk_flush_restore_request(struct request *rq)
static bool blk_flush_queue_rq(struct request *rq, bool add_front)
{
if (rq->q->mq_ops) {
- struct request_queue *q = rq->q;
-
- blk_mq_add_to_requeue_list(rq, add_front);
- blk_mq_kick_requeue_list(q);
+ blk_mq_add_to_requeue_list(rq, add_front, true);
return false;
} else {
if (add_front)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4945437..688bcc3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -492,12 +492,12 @@ static void __blk_mq_requeue_request(struct request *rq)
}
}
-void blk_mq_requeue_request(struct request *rq)
+void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
{
__blk_mq_requeue_request(rq);
BUG_ON(blk_queued_rq(rq));
- blk_mq_add_to_requeue_list(rq, true);
+ blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
}
EXPORT_SYMBOL(blk_mq_requeue_request);
@@ -535,7 +535,8 @@ static void blk_mq_requeue_work(struct work_struct *work)
blk_mq_start_hw_queues(q);
}
-void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
+void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
+ bool kick_requeue_list)
{
struct request_queue *q = rq->q;
unsigned long flags;
@@ -554,6 +555,9 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
list_add_tail(&rq->queuelist, &q->requeue_list);
}
spin_unlock_irqrestore(&q->requeue_lock, flags);
+
+ if (kick_requeue_list)
+ blk_mq_kick_requeue_list(q);
}
EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9908597..1ca702d 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2043,7 +2043,7 @@ static int blkif_recover(struct blkfront_info *info)
/* Requeue pending requests (flush or discard) */
list_del_init(&req->queuelist);
BUG_ON(req->nr_phys_segments > segs);
- blk_mq_requeue_request(req);
+ blk_mq_requeue_request(req, false);
}
blk_mq_kick_requeue_list(info->rq);
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index dc75bea..fbd37b4 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -354,7 +354,7 @@ EXPORT_SYMBOL(dm_mq_kick_requeue_list);
static void dm_mq_delay_requeue_request(struct request *rq, unsigned long msecs)
{
- blk_mq_requeue_request(rq);
+ blk_mq_requeue_request(rq, false);
__dm_mq_kick_requeue_list(rq->q, msecs);
}
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 79e679d..7bb73ba 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -203,7 +203,7 @@ void nvme_requeue_req(struct request *req)
{
unsigned long flags;
- blk_mq_requeue_request(req);
+ blk_mq_requeue_request(req, false);
spin_lock_irqsave(req->q->queue_lock, flags);
if (!blk_queue_stopped(req->q))
blk_mq_kick_requeue_list(req->q);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2cca9cf..ab5b06f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -86,10 +86,8 @@ scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
{
struct scsi_device *sdev = cmd->device;
- struct request_queue *q = cmd->request->q;
- blk_mq_requeue_request(cmd->request);
- blk_mq_kick_requeue_list(q);
+ blk_mq_requeue_request(cmd->request, true);
put_device(&sdev->sdev_gendev);
}
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 61be48b..76f6319 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -218,8 +218,9 @@ void blk_mq_start_request(struct request *rq);
void blk_mq_end_request(struct request *rq, int error);
void __blk_mq_end_request(struct request *rq, int error);
-void blk_mq_requeue_request(struct request *rq);
-void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
+void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
+void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
+ bool kick_requeue_list);
void blk_mq_cancel_requeue_work(struct request_queue *q);
void blk_mq_kick_requeue_list(struct request_queue *q);
void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
--
2.10.1
--
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^ permalink raw reply related
* [PATCH 07/12] dm: Use BLK_MQ_S_STOPPED instead of QUEUE_FLAG_STOPPED in blk-mq code
From: Bart Van Assche @ 2016-10-26 22:54 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
Instead of manipulating both QUEUE_FLAG_STOPPED and BLK_MQ_S_STOPPED
in the dm start and stop queue functions, only manipulate the latter
flag. Change blk_queue_stopped() tests into blk_mq_queue_stopped().
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-rq.c | 18 ++----------------
1 file changed, 2 insertions(+), 16 deletions(-)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index fbd37b4..d47a504 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -75,12 +75,6 @@ static void dm_old_start_queue(struct request_queue *q)
static void dm_mq_start_queue(struct request_queue *q)
{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- queue_flag_clear(QUEUE_FLAG_STOPPED, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
blk_mq_start_stopped_hw_queues(q, true);
blk_mq_kick_requeue_list(q);
}
@@ -105,16 +99,8 @@ static void dm_old_stop_queue(struct request_queue *q)
static void dm_mq_stop_queue(struct request_queue *q)
{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- if (blk_queue_stopped(q)) {
- spin_unlock_irqrestore(q->queue_lock, flags);
+ if (blk_mq_queue_stopped(q))
return;
- }
-
- queue_flag_set(QUEUE_FLAG_STOPPED, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
/* Avoid that requeuing could restart the queue. */
blk_mq_cancel_requeue_work(q);
@@ -341,7 +327,7 @@ static void __dm_mq_kick_requeue_list(struct request_queue *q, unsigned long mse
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- if (!blk_queue_stopped(q))
+ if (!blk_mq_queue_stopped(q))
blk_mq_delay_kick_requeue_list(q, msecs);
spin_unlock_irqrestore(q->queue_lock, flags);
}
--
2.10.1
^ permalink raw reply related
* [PATCH 08/12] dm: Fix a race condition related to stopping and starting queues
From: Bart Van Assche @ 2016-10-26 22:54 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
Ensure that all ongoing dm_mq_queue_rq() and dm_mq_requeue_request()
calls have stopped before setting the "queue stopped" flag. This
allows to remove the "queue stopped" test from dm_mq_queue_rq() and
dm_mq_requeue_request(). This patch fixes a race condition because
dm_mq_queue_rq() is called without holding the queue lock and hence
BLK_MQ_S_STOPPED can be set at any time while dm_mq_queue_rq() is
in progress. This patch prevents that the following hang occurs
sporadically when using dm-mq:
INFO: task systemd-udevd:10111 blocked for more than 480 seconds.
Call Trace:
[<ffffffff8161f397>] schedule+0x37/0x90
[<ffffffff816239ef>] schedule_timeout+0x27f/0x470
[<ffffffff8161e76f>] io_schedule_timeout+0x9f/0x110
[<ffffffff8161fb36>] bit_wait_io+0x16/0x60
[<ffffffff8161f929>] __wait_on_bit_lock+0x49/0xa0
[<ffffffff8114fe69>] __lock_page+0xb9/0xc0
[<ffffffff81165d90>] truncate_inode_pages_range+0x3e0/0x760
[<ffffffff81166120>] truncate_inode_pages+0x10/0x20
[<ffffffff81212a20>] kill_bdev+0x30/0x40
[<ffffffff81213d41>] __blkdev_put+0x71/0x360
[<ffffffff81214079>] blkdev_put+0x49/0x170
[<ffffffff812141c0>] blkdev_close+0x20/0x30
[<ffffffff811d48e8>] __fput+0xe8/0x1f0
[<ffffffff811d4a29>] ____fput+0x9/0x10
[<ffffffff810842d3>] task_work_run+0x83/0xb0
[<ffffffff8106606e>] do_exit+0x3ee/0xc40
[<ffffffff8106694b>] do_group_exit+0x4b/0xc0
[<ffffffff81073d9a>] get_signal+0x2ca/0x940
[<ffffffff8101bf43>] do_signal+0x23/0x660
[<ffffffff810022b3>] exit_to_usermode_loop+0x73/0xb0
[<ffffffff81002cb0>] syscall_return_slowpath+0xb0/0xc0
[<ffffffff81624e33>] entry_SYSCALL_64_fastpath+0xa6/0xa8
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-rq.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index d47a504..107ed19 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -105,6 +105,8 @@ static void dm_mq_stop_queue(struct request_queue *q)
/* Avoid that requeuing could restart the queue. */
blk_mq_cancel_requeue_work(q);
blk_mq_stop_hw_queues(q);
+ /* Wait until dm_mq_queue_rq() has finished. */
+ blk_mq_quiesce_queue(q);
}
void dm_stop_queue(struct request_queue *q)
@@ -887,17 +889,6 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
dm_put_live_table(md, srcu_idx);
}
- /*
- * On suspend dm_stop_queue() handles stopping the blk-mq
- * request_queue BUT: even though the hw_queues are marked
- * BLK_MQ_S_STOPPED at that point there is still a race that
- * is allowing block/blk-mq.c to call ->queue_rq against a
- * hctx that it really shouldn't. The following check guards
- * against this rarity (albeit _not_ race-free).
- */
- if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
- return BLK_MQ_RQ_QUEUE_BUSY;
-
if (ti->type->busy && ti->type->busy(ti))
return BLK_MQ_RQ_QUEUE_BUSY;
--
2.10.1
^ permalink raw reply related
* [PATCH 09/12] SRP transport: Move queuecommand() wait code to SCSI core
From: Bart Van Assche @ 2016-10-26 22:55 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
Additionally, rename srp_wait_for_queuecommand() into
scsi_wait_for_queuecommand() and add a comment about the
queuecommand() call from scsi_send_eh_cmnd().
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Doug Ledford <dledford@redhat.com>
---
drivers/scsi/scsi_lib.c | 41 +++++++++++++++++++++++++++++++++++++++
drivers/scsi/scsi_transport_srp.c | 35 ++-------------------------------
include/scsi/scsi_host.h | 1 +
3 files changed, 44 insertions(+), 33 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ab5b06f..c1561e7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2722,6 +2722,47 @@ void sdev_evt_send_simple(struct scsi_device *sdev,
EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
/**
+ * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
+ * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
+ *
+ * To do: add support for scsi-mq in this function.
+ */
+static int scsi_request_fn_active(struct Scsi_Host *shost)
+{
+ struct scsi_device *sdev;
+ struct request_queue *q;
+ int request_fn_active = 0;
+
+ shost_for_each_device(sdev, shost) {
+ q = sdev->request_queue;
+
+ spin_lock_irq(q->queue_lock);
+ request_fn_active += q->request_fn_active;
+ spin_unlock_irq(q->queue_lock);
+ }
+
+ return request_fn_active;
+}
+
+/**
+ * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
+ * @shost: SCSI host pointer.
+ *
+ * Wait until the ongoing shost->hostt->queuecommand() calls that are
+ * invoked from scsi_request_fn() have finished.
+ *
+ * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
+ * scsi_internal_device_block() has blocked a SCSI device and remove and also
+ * remove the rport mutex lock and unlock calls from srp_queuecommand().
+ */
+void scsi_wait_for_queuecommand(struct Scsi_Host *shost)
+{
+ while (scsi_request_fn_active(shost))
+ msleep(20);
+}
+EXPORT_SYMBOL(scsi_wait_for_queuecommand);
+
+/**
* scsi_device_quiesce - Block user issued commands.
* @sdev: scsi device to quiesce.
*
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index e3cd3ec..8b190dc 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -24,7 +24,6 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
-#include <linux/delay.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
@@ -402,36 +401,6 @@ static void srp_reconnect_work(struct work_struct *work)
}
}
-/**
- * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
- * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
- *
- * To do: add support for scsi-mq in this function.
- */
-static int scsi_request_fn_active(struct Scsi_Host *shost)
-{
- struct scsi_device *sdev;
- struct request_queue *q;
- int request_fn_active = 0;
-
- shost_for_each_device(sdev, shost) {
- q = sdev->request_queue;
-
- spin_lock_irq(q->queue_lock);
- request_fn_active += q->request_fn_active;
- spin_unlock_irq(q->queue_lock);
- }
-
- return request_fn_active;
-}
-
-/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */
-static void srp_wait_for_queuecommand(struct Scsi_Host *shost)
-{
- while (scsi_request_fn_active(shost))
- msleep(20);
-}
-
static void __rport_fail_io_fast(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
@@ -446,7 +415,7 @@ static void __rport_fail_io_fast(struct srp_rport *rport)
/* Involve the LLD if possible to terminate all I/O on the rport. */
i = to_srp_internal(shost->transportt);
if (i->f->terminate_rport_io) {
- srp_wait_for_queuecommand(shost);
+ scsi_wait_for_queuecommand(shost);
i->f->terminate_rport_io(rport);
}
}
@@ -576,7 +545,7 @@ int srp_reconnect_rport(struct srp_rport *rport)
if (res)
goto out;
scsi_target_block(&shost->shost_gendev);
- srp_wait_for_queuecommand(shost);
+ scsi_wait_for_queuecommand(shost);
res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
pr_debug("%s (state %d): transport.reconnect() returned %d\n",
dev_name(&shost->shost_gendev), rport->state, res);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7e4cd53..0e2c361 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -789,6 +789,7 @@ extern void scsi_remove_host(struct Scsi_Host *);
extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
extern void scsi_host_put(struct Scsi_Host *t);
extern struct Scsi_Host *scsi_host_lookup(unsigned short);
+extern void scsi_wait_for_queuecommand(struct Scsi_Host *shost);
extern const char *scsi_host_state_name(enum scsi_host_state);
extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
--
2.10.1
^ permalink raw reply related
* [PATCH 10/12] SRP transport, scsi-mq: Wait for .queue_rq() if necessary
From: Bart Van Assche @ 2016-10-26 22:55 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
Ensure that if scsi-mq is enabled that scsi_wait_for_queuecommand()
waits until ongoing shost->hostt->queuecommand() calls have finished.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Doug Ledford <dledford@redhat.com>
---
drivers/scsi/scsi_lib.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c1561e7..9b8b19e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2724,8 +2724,6 @@ EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
/**
* scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
* @shost: SCSI host for which to count the number of scsi_request_fn() callers.
- *
- * To do: add support for scsi-mq in this function.
*/
static int scsi_request_fn_active(struct Scsi_Host *shost)
{
@@ -2744,12 +2742,20 @@ static int scsi_request_fn_active(struct Scsi_Host *shost)
return request_fn_active;
}
+static void scsi_mq_wait_for_queuecommand(struct Scsi_Host *shost)
+{
+ struct scsi_device *sdev;
+
+ shost_for_each_device(sdev, shost)
+ blk_mq_quiesce_queue(sdev->request_queue);
+}
+
/**
* scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
* @shost: SCSI host pointer.
*
* Wait until the ongoing shost->hostt->queuecommand() calls that are
- * invoked from scsi_request_fn() have finished.
+ * invoked from either scsi_request_fn() or scsi_queue_rq() have finished.
*
* To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
* scsi_internal_device_block() has blocked a SCSI device and remove and also
@@ -2757,8 +2763,12 @@ static int scsi_request_fn_active(struct Scsi_Host *shost)
*/
void scsi_wait_for_queuecommand(struct Scsi_Host *shost)
{
- while (scsi_request_fn_active(shost))
- msleep(20);
+ if (shost->use_blk_mq) {
+ scsi_mq_wait_for_queuecommand(shost);
+ } else {
+ while (scsi_request_fn_active(shost))
+ msleep(20);
+ }
}
EXPORT_SYMBOL(scsi_wait_for_queuecommand);
--
2.10.1
^ permalink raw reply related
* [PATCH 11/12] nvme: Use BLK_MQ_S_STOPPED instead of QUEUE_FLAG_STOPPED in blk-mq code
From: Bart Van Assche @ 2016-10-26 22:56 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Make nvme_requeue_req() check BLK_MQ_S_STOPPED instead of
QUEUE_FLAG_STOPPED. Remove the QUEUE_FLAG_STOPPED manipulations
that became superfluous because of this change. Change
blk_queue_stopped() tests into blk_mq_queue_stopped().
This patch fixes a race condition: using queue_flag_clear_unlocked()
is not safe if any other function that manipulates the queue flags
can be called concurrently, e.g. blk_cleanup_queue().
Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Keith Busch <keith.busch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
---
drivers/nvme/host/core.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 7bb73ba..b662416 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -205,7 +205,7 @@ void nvme_requeue_req(struct request *req)
blk_mq_requeue_request(req, false);
spin_lock_irqsave(req->q->queue_lock, flags);
- if (!blk_queue_stopped(req->q))
+ if (!blk_mq_queue_stopped(req->q))
blk_mq_kick_requeue_list(req->q);
spin_unlock_irqrestore(req->q->queue_lock, flags);
}
@@ -2079,10 +2079,6 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl)
mutex_lock(&ctrl->namespaces_mutex);
list_for_each_entry(ns, &ctrl->namespaces, list) {
- spin_lock_irq(ns->queue->queue_lock);
- queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);
- spin_unlock_irq(ns->queue->queue_lock);
-
blk_mq_cancel_requeue_work(ns->queue);
blk_mq_stop_hw_queues(ns->queue);
}
@@ -2096,7 +2092,6 @@ void nvme_start_queues(struct nvme_ctrl *ctrl)
mutex_lock(&ctrl->namespaces_mutex);
list_for_each_entry(ns, &ctrl->namespaces, list) {
- queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);
blk_mq_start_stopped_hw_queues(ns->queue, true);
blk_mq_kick_requeue_list(ns->queue);
}
--
2.10.1
--
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^ permalink raw reply related
* [PATCH 12/12] nvme: Fix a race condition related to stopping queues
From: Bart Van Assche @ 2016-10-26 22:56 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lei,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Avoid that nvme_queue_rq() is still running when nvme_stop_queues()
returns.
Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Reviewed-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Keith Busch <keith.busch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/nvme/host/core.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index b662416..d6ab9a0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -201,13 +201,7 @@ static struct nvme_ns *nvme_get_ns_from_disk(struct gendisk *disk)
void nvme_requeue_req(struct request *req)
{
- unsigned long flags;
-
- blk_mq_requeue_request(req, false);
- spin_lock_irqsave(req->q->queue_lock, flags);
- if (!blk_mq_queue_stopped(req->q))
- blk_mq_kick_requeue_list(req->q);
- spin_unlock_irqrestore(req->q->queue_lock, flags);
+ blk_mq_requeue_request(req, !blk_mq_queue_stopped(req->q));
}
EXPORT_SYMBOL_GPL(nvme_requeue_req);
@@ -2079,8 +2073,11 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl)
mutex_lock(&ctrl->namespaces_mutex);
list_for_each_entry(ns, &ctrl->namespaces, list) {
- blk_mq_cancel_requeue_work(ns->queue);
- blk_mq_stop_hw_queues(ns->queue);
+ struct request_queue *q = ns->queue;
+
+ blk_mq_cancel_requeue_work(q);
+ blk_mq_stop_hw_queues(q);
+ blk_mq_quiesce_queue(q);
}
mutex_unlock(&ctrl->namespaces_mutex);
}
--
2.10.1
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* Trouble enabling iSER for ConnectX-4 Lx
From: Robert LeBlanc @ 2016-10-26 23:13 UTC (permalink / raw)
To: linux-rdma
We have some ConnectX-4 Lx cards that I'm trying to test RoCE and iSER
on. I downloaded and installed the Mellanox drivers with VMA [0]. I
was able to run the ib_read_bw tests over the adapters after
installing the infiniband-diags and perftest RPMs. When I went to
configure LIO for iSER, I'm getting the message "Cannot change iser"
on step 6 in the procedure here [1] which I've done many times with
Infiniband without issues. I navigated to
/sys/kernel/config/target/iscsi/{iqn}/tpgt_1/np/{portal_ip:port} and
sure enough, I can't write '1' into iser. The kernel is not giving any
messages and the ib_isert module is loaded. This is on 4.4.27,
Mellanox driver 3.4-1.0.0.3 built with `./install --add-kernel-support
--skip-repo --tmpdir /root/junk --vma`
# mstflint -d 4:00.0 q
Image type: FS3
FW Version: 14.16.1020
FW Release Date: 20.6.2016
Rom Info: type=UEFI version=14.10.16
type=PXE version=3.4.812 devid=4117
Description: UID GuidsNumber
Base GUID: 0cc47a000089f706 4
Base MAC: 00000cc47a89f706 4
Image VSD:
Device VSD:
PSID: SM_2001000001034
# ibstatus
Infiniband device 'mlx5_0' port 1 status:
default gid: fe80:0000:0000:0000:0ec4:7aff:fe89:f706
base lid: 0x0
sm lid: 0x0
state: 4: ACTIVE
phys state: 5: LinkUp
rate: 25 Gb/sec (1X EDR)
link_layer: Ethernet
Infiniband device 'mlx5_1' port 1 status:
default gid: fe80:0000:0000:0000:0ec4:7aff:fe89:f707
base lid: 0x0
sm lid: 0x0
state: 4: ACTIVE
phys state: 5: LinkUp
rate: 25 Gb/sec (1X EDR)
link_layer: Ethernet
Any ideas of what I'm doing wrong here? I don't have any experience
with RoCE, so I'm sure I'm doing something wrong. And the manual has
nothing about configuring RoCE other than enabling --vma when
installing the drivers [2].
Thanks,
Robert LeBlanc
[0] http://www.mellanox.com/page/products_dyn?product_family=27
[1] https://community.mellanox.com/docs/DOC-1472
[2] http://www.mellanox.com/related-docs/prod_software/Mellanox_EN_for_Linux_User_Manual_v3_40.pdf
----------------
Robert LeBlanc
PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1
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^ permalink raw reply
* Re: [PATCH v4 0/12] Fix race conditions related to stopping block layer queues
From: Jens Axboe @ 2016-10-26 23:28 UTC (permalink / raw)
To: Bart Van Assche
Cc: Christoph Hellwig, James Bottomley, Martin K. Petersen,
Mike Snitzer, Doug Ledford, Keith Busch, Ming Lin,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <b22edafc-725f-0419-d074-34d35d57d126@sandisk.com>
On 10/26/2016 04:49 PM, Bart Van Assche wrote:
> Hello Jens,
>
> Multiple block drivers need the functionality to stop a request queue
> and to wait until all ongoing request_fn() / queue_rq() calls have
> finished without waiting until all outstanding requests have finished.
> Hence this patch series that introduces the blk_mq_quiesce_queue()
> function. The dm-mq, SRP and NVMe patches in this patch series are three
> examples of where these functions are useful. These patches have been
> tested on top of kernel v4.9-rc1. The following tests have been run to
> verify this patch series:
> - Mike's mptest suite that stress-tests dm-multipath.
> - My own srp-test suite that stress-tests SRP on top of dm-multipath.
> - fio on top of the NVMeOF host driver that was connected to the NVMeOF
> target driver on the same host.
> - Laurence verified the previous version (v3) of this patch series by
> running it through the Red Hat SRP and NVMe test suites.
This looks pretty good, I'll run some testing on it tomorrow and do a
full review, hopefully we can get it applied sooner rather than later
for the next series.
--
Jens Axboe
^ permalink raw reply
* Re: [PATCH 05/12] blk-mq: Introduce blk_mq_quiesce_queue()
From: Ming Lei @ 2016-10-27 1:30 UTC (permalink / raw)
To: Bart Van Assche
Cc: Jens Axboe, Christoph Hellwig, James Bottomley,
Martin K. Petersen, Mike Snitzer, Doug Ledford, Keith Busch,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <5143c240-39af-9fe2-d3e6-ed69f9c20531-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
On Thu, Oct 27, 2016 at 6:53 AM, Bart Van Assche
<bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> wrote:
> blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations
> have finished. This function does *not* wait until all outstanding
> requests have finished (this means invocation of request.end_io()).
> The algorithm used by blk_mq_quiesce_queue() is as follows:
> * Hold either an RCU read lock or an SRCU read lock around
> .queue_rq() calls. The former is used if .queue_rq() does not
> block and the latter if .queue_rq() may block.
> * blk_mq_quiesce_queue() calls synchronize_srcu() or
> synchronize_rcu() to wait for .queue_rq() invocations that
> started before blk_mq_quiesce_queue() was called.
> * The blk_mq_hctx_stopped() calls that control whether or not
> .queue_rq() will be called are called with the (S)RCU read lock
> held. This is necessary to avoid race conditions against
> the "blk_mq_stop_hw_queues(q); blk_mq_quiesce_queue(q);"
> sequence from another thread.
>
> Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
> Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> Cc: Ming Lei <tom.leiming-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>
> Cc: Johannes Thumshirn <jthumshirn-l3A5Bk7waGM@public.gmane.org>
> ---
> block/Kconfig | 1 +
> block/blk-mq.c | 69 +++++++++++++++++++++++++++++++++++++++++++++-----
> include/linux/blk-mq.h | 3 +++
> include/linux/blkdev.h | 1 +
> 4 files changed, 67 insertions(+), 7 deletions(-)
>
> diff --git a/block/Kconfig b/block/Kconfig
> index 1d4d624..0562ef9 100644
> --- a/block/Kconfig
> +++ b/block/Kconfig
> @@ -5,6 +5,7 @@ menuconfig BLOCK
> bool "Enable the block layer" if EXPERT
> default y
> select SBITMAP
> + select SRCU
> help
> Provide block layer support for the kernel.
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 0cf21c2..4945437 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -115,6 +115,31 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
> }
> EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
>
> +/**
> + * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished
> + * @q: request queue.
> + *
> + * Note: this function does not prevent that the struct request end_io()
> + * callback function is invoked. Additionally, it is not prevented that
> + * new queue_rq() calls occur unless the queue has been stopped first.
> + */
> +void blk_mq_quiesce_queue(struct request_queue *q)
> +{
> + struct blk_mq_hw_ctx *hctx;
> + unsigned int i;
> + bool rcu = false;
Before synchronizing SRCU/RCU, we have to set a per-hctx flag
or per-queue flag to block comming .queue_rq(), seems I mentioned
that before:
https://www.spinics.net/lists/linux-rdma/msg41389.html
> +
> + queue_for_each_hw_ctx(q, hctx, i) {
> + if (hctx->flags & BLK_MQ_F_BLOCKING)
> + synchronize_srcu(&hctx->queue_rq_srcu);
> + else
> + rcu = true;
> + }
> + if (rcu)
> + synchronize_rcu();
> +}
> +EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
> +
> void blk_mq_wake_waiters(struct request_queue *q)
> {
> struct blk_mq_hw_ctx *hctx;
> @@ -778,7 +803,7 @@ static inline unsigned int queued_to_index(unsigned int queued)
> * of IO. In particular, we'd like FIFO behaviour on handling existing
> * items on the hctx->dispatch list. Ignore that for now.
> */
> -static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
> +static void blk_mq_process_rq_list(struct blk_mq_hw_ctx *hctx)
> {
> struct request_queue *q = hctx->queue;
> struct request *rq;
> @@ -790,9 +815,6 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
> if (unlikely(blk_mq_hctx_stopped(hctx)))
> return;
>
> - WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
> - cpu_online(hctx->next_cpu));
> -
> hctx->run++;
>
> /*
> @@ -883,6 +905,24 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
> }
> }
>
> +static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
> +{
> + int srcu_idx;
> +
> + WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
> + cpu_online(hctx->next_cpu));
> +
> + if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
> + rcu_read_lock();
> + blk_mq_process_rq_list(hctx);
> + rcu_read_unlock();
> + } else {
> + srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
> + blk_mq_process_rq_list(hctx);
> + srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
> + }
> +}
> +
> /*
> * It'd be great if the workqueue API had a way to pass
> * in a mask and had some smarts for more clever placement.
> @@ -1293,7 +1333,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
> struct blk_map_ctx data;
> struct request *rq;
> - unsigned int request_count = 0;
> + unsigned int request_count = 0, srcu_idx;
> struct blk_plug *plug;
> struct request *same_queue_rq = NULL;
> blk_qc_t cookie;
> @@ -1336,7 +1376,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> blk_mq_bio_to_request(rq, bio);
>
> /*
> - * We do limited pluging. If the bio can be merged, do that.
> + * We do limited plugging. If the bio can be merged, do that.
> * Otherwise the existing request in the plug list will be
> * issued. So the plug list will have one request at most
> */
> @@ -1356,7 +1396,16 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> blk_mq_put_ctx(data.ctx);
> if (!old_rq)
> goto done;
> - blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
> +
> + if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) {
> + rcu_read_lock();
> + blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
> + rcu_read_unlock();
> + } else {
> + srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu);
> + blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
> + srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx);
> + }
> goto done;
> }
>
> @@ -1635,6 +1684,9 @@ static void blk_mq_exit_hctx(struct request_queue *q,
> if (set->ops->exit_hctx)
> set->ops->exit_hctx(hctx, hctx_idx);
>
> + if (hctx->flags & BLK_MQ_F_BLOCKING)
> + cleanup_srcu_struct(&hctx->queue_rq_srcu);
> +
> blk_mq_remove_cpuhp(hctx);
> blk_free_flush_queue(hctx->fq);
> sbitmap_free(&hctx->ctx_map);
> @@ -1715,6 +1767,9 @@ static int blk_mq_init_hctx(struct request_queue *q,
> flush_start_tag + hctx_idx, node))
> goto free_fq;
>
> + if (hctx->flags & BLK_MQ_F_BLOCKING)
> + init_srcu_struct(&hctx->queue_rq_srcu);
> +
> return 0;
>
> free_fq:
> diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
> index aa93000..61be48b 100644
> --- a/include/linux/blk-mq.h
> +++ b/include/linux/blk-mq.h
> @@ -3,6 +3,7 @@
>
> #include <linux/blkdev.h>
> #include <linux/sbitmap.h>
> +#include <linux/srcu.h>
>
> struct blk_mq_tags;
> struct blk_flush_queue;
> @@ -35,6 +36,8 @@ struct blk_mq_hw_ctx {
>
> struct blk_mq_tags *tags;
>
> + struct srcu_struct queue_rq_srcu;
> +
> unsigned long queued;
> unsigned long run;
> #define BLK_MQ_MAX_DISPATCH_ORDER 7
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index c47c358..8259d87 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -824,6 +824,7 @@ extern void __blk_run_queue(struct request_queue *q);
> extern void __blk_run_queue_uncond(struct request_queue *q);
> extern void blk_run_queue(struct request_queue *);
> extern void blk_run_queue_async(struct request_queue *q);
> +extern void blk_mq_quiesce_queue(struct request_queue *q);
> extern int blk_rq_map_user(struct request_queue *, struct request *,
> struct rq_map_data *, void __user *, unsigned long,
> gfp_t);
> --
> 2.10.1
>
--
Ming Lei
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^ permalink raw reply
* Re: [PATCH 02/12] blk-mq: Introduce blk_mq_hctx_stopped()
From: Ming Lei @ 2016-10-27 1:33 UTC (permalink / raw)
To: Bart Van Assche
Cc: Jens Axboe, Christoph Hellwig, James Bottomley,
Martin K. Petersen, Mike Snitzer, Doug Ledford, Keith Busch,
Laurence Oberman, linux-block@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nvme@lists.infradead.org
In-Reply-To: <0de50789-e3b7-0a07-73c1-4fb87b1f957e@sandisk.com>
On Thu, Oct 27, 2016 at 6:51 AM, Bart Van Assche
<bart.vanassche@sandisk.com> wrote:
> Multiple functions test the BLK_MQ_S_STOPPED bit so introduce
> a helper function that performs this test.
>
> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.com>
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
> ---
> block/blk-mq.c | 12 ++++++------
> block/blk-mq.h | 5 +++++
> 2 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index b5dcafb..b52b3a6 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -787,7 +787,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
> struct list_head *dptr;
> int queued;
>
> - if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
> + if (unlikely(blk_mq_hctx_stopped(hctx)))
> return;
>
> WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
> @@ -912,8 +912,8 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
>
> void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
> {
> - if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
> - !blk_mq_hw_queue_mapped(hctx)))
> + if (unlikely(blk_mq_hctx_stopped(hctx) ||
> + !blk_mq_hw_queue_mapped(hctx)))
> return;
>
> if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
> @@ -938,7 +938,7 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async)
> queue_for_each_hw_ctx(q, hctx, i) {
> if ((!blk_mq_hctx_has_pending(hctx) &&
> list_empty_careful(&hctx->dispatch)) ||
> - test_bit(BLK_MQ_S_STOPPED, &hctx->state))
> + blk_mq_hctx_stopped(hctx))
> continue;
>
> blk_mq_run_hw_queue(hctx, async);
> @@ -988,7 +988,7 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
> int i;
>
> queue_for_each_hw_ctx(q, hctx, i) {
> - if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
> + if (!blk_mq_hctx_stopped(hctx))
> continue;
>
> clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
> @@ -1332,7 +1332,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> blk_mq_put_ctx(data.ctx);
> if (!old_rq)
> goto done;
> - if (test_bit(BLK_MQ_S_STOPPED, &data.hctx->state) ||
> + if (blk_mq_hctx_stopped(data.hctx) ||
> blk_mq_direct_issue_request(old_rq, &cookie) != 0)
> blk_mq_insert_request(old_rq, false, true, true);
> goto done;
> diff --git a/block/blk-mq.h b/block/blk-mq.h
> index e5d2524..ac772da 100644
> --- a/block/blk-mq.h
> +++ b/block/blk-mq.h
> @@ -100,6 +100,11 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
> data->hctx = hctx;
> }
>
> +static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
> +{
> + return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
> +}
> +
> static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
> {
> return hctx->nr_ctx && hctx->tags;
> --
> 2.10.1
>
--
Ming Lei
^ permalink raw reply
* Re: [PATCH 05/12] blk-mq: Introduce blk_mq_quiesce_queue()
From: Bart Van Assche @ 2016-10-27 2:04 UTC (permalink / raw)
To: Ming Lei
Cc: Jens Axboe, Christoph Hellwig, James Bottomley,
Martin K. Petersen, Mike Snitzer, Doug Ledford, Keith Busch,
Laurence Oberman,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
In-Reply-To: <CACVXFVPWL=izFmUPtpi-+RLrhNX0LFfw2m6eurgMC5GvfDWsxQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On 10/26/16 18:30, Ming Lei wrote:
> On Thu, Oct 27, 2016 at 6:53 AM, Bart Van Assche
> <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> wrote:
>> blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations
>> have finished. This function does *not* wait until all outstanding
>> requests have finished (this means invocation of request.end_io()).
>> The algorithm used by blk_mq_quiesce_queue() is as follows:
>> * Hold either an RCU read lock or an SRCU read lock around
>> .queue_rq() calls. The former is used if .queue_rq() does not
>> block and the latter if .queue_rq() may block.
>> * blk_mq_quiesce_queue() calls synchronize_srcu() or
>> synchronize_rcu() to wait for .queue_rq() invocations that
>> started before blk_mq_quiesce_queue() was called.
>> * The blk_mq_hctx_stopped() calls that control whether or not
>> .queue_rq() will be called are called with the (S)RCU read lock
>> held. This is necessary to avoid race conditions against
>> the "blk_mq_stop_hw_queues(q); blk_mq_quiesce_queue(q);"
>> sequence from another thread.
>>
>> Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
>> Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
>> Cc: Ming Lei <tom.leiming-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>
>> Cc: Johannes Thumshirn <jthumshirn-l3A5Bk7waGM@public.gmane.org>
>> ---
>> block/Kconfig | 1 +
>> block/blk-mq.c | 69 +++++++++++++++++++++++++++++++++++++++++++++-----
>> include/linux/blk-mq.h | 3 +++
>> include/linux/blkdev.h | 1 +
>> 4 files changed, 67 insertions(+), 7 deletions(-)
>>
>> diff --git a/block/Kconfig b/block/Kconfig
>> index 1d4d624..0562ef9 100644
>> --- a/block/Kconfig
>> +++ b/block/Kconfig
>> @@ -5,6 +5,7 @@ menuconfig BLOCK
>> bool "Enable the block layer" if EXPERT
>> default y
>> select SBITMAP
>> + select SRCU
>> help
>> Provide block layer support for the kernel.
>>
>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>> index 0cf21c2..4945437 100644
>> --- a/block/blk-mq.c
>> +++ b/block/blk-mq.c
>> @@ -115,6 +115,31 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
>> }
>> EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
>>
>> +/**
>> + * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished
>> + * @q: request queue.
>> + *
>> + * Note: this function does not prevent that the struct request end_io()
>> + * callback function is invoked. Additionally, it is not prevented that
>> + * new queue_rq() calls occur unless the queue has been stopped first.
>> + */
>> +void blk_mq_quiesce_queue(struct request_queue *q)
>> +{
>> + struct blk_mq_hw_ctx *hctx;
>> + unsigned int i;
>> + bool rcu = false;
>
> Before synchronizing SRCU/RCU, we have to set a per-hctx flag
> or per-queue flag to block comming .queue_rq(), seems I mentioned
> that before:
>
> https://www.spinics.net/lists/linux-rdma/msg41389.html
Hello Ming,
Thanks for having included an URL to an archived version of that
discussion. What I remember about that discussion is that I proposed to
use the existing flag BLK_MQ_S_STOPPED instead of introducing a
new QUEUE_FLAG_QUIESCING flag and that you agreed with that proposal.
See also https://www.spinics.net/lists/linux-rdma/msg41430.html.
Bart.
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