Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread Bart Van Assche
On Thu, 2018-02-08 at 09:40 -0800, t...@kernel.org wrote: > Heh, sorry about not being clear. What I'm trying to say is that > scmd->device != NULL && device->host == NULL. Or was this what you > were saying all along? What I agree with is that the request pointer (req argument) is stored in

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
On Thu, Feb 08, 2018 at 05:48:32PM +, Bart Van Assche wrote: > On Thu, 2018-02-08 at 09:40 -0800, t...@kernel.org wrote: > > Heh, sorry about not being clear. What I'm trying to say is that > > scmd->device != NULL && device->host == NULL. Or was this what you > > were saying all along? > >

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread Bart Van Assche
On Thu, 2018-02-08 at 09:00 -0800, t...@kernel.org wrote: > On Thu, Feb 08, 2018 at 04:31:43PM +, Bart Van Assche wrote: > > The crash is reported at address scsi_times_out+0x17 == scsi_times_out+23. > > The > > instruction at that address tries to dereference scsi_cmnd.device (%rax). > >

Re: [PATCH 00/24] InfiniBand Transport (IBTRS) and Network Block Device (IBNBD)

2018-02-08 Thread Danil Kipnis
On Wed, Feb 7, 2018 at 6:32 PM, Bart Van Assche wrote: > On Wed, 2018-02-07 at 18:18 +0100, Roman Penyaev wrote: >> So the question is: are there real life setups where >> some of the local IB network members can be untrusted? > > Hello Roman, > > You may want to read more

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread Bart Van Assche
On Thu, 2018-02-08 at 09:19 -0800, t...@kernel.org wrote: > Hello, Bart. > > On Thu, Feb 08, 2018 at 05:10:45PM +, Bart Van Assche wrote: > > I think "dereferencing a pointer" means reading the memory location that > > pointer points > > at? Anyway, I think we both interpret the crash report

[PATCH v7 1/2] xfs: remove assert to check bytes returned

2018-02-08 Thread Goldwyn Rodrigues
From: Goldwyn Rodrigues Since we can return less than count in case of partial direct writes, remove the ASSERT. Signed-off-by: Goldwyn Rodrigues --- fs/xfs/xfs_file.c | 6 -- 1 file changed, 6 deletions(-) Changes since v6: - Reordered to before

[PATCH v7 2/2] Return bytes transferred for partial direct I/O

2018-02-08 Thread Goldwyn Rodrigues
From: Goldwyn Rodrigues In case direct I/O encounters an error midway, it returns the error. Instead it should be returning the number of bytes transferred so far. Test case for filesystems (with ENOSPC): 1. Create an almost full filesystem 2. Create a file, say

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread Bart Van Assche
On Thu, 2018-02-08 at 07:39 -0800, t...@kernel.org wrote: > On Thu, Feb 08, 2018 at 01:09:57AM +, Bart Van Assche wrote: > > On Wed, 2018-02-07 at 23:48 +, Bart Van Assche wrote: > > > With this patch applied I see requests for which it seems like the > > > timeout handler > > > did not

Re: [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq

2018-02-08 Thread Ming Lei
On Thu, Feb 08, 2018 at 08:00:29AM +0100, Hannes Reinecke wrote: > On 02/07/2018 03:14 PM, Kashyap Desai wrote: > >> -Original Message- > >> From: Ming Lei [mailto:ming@redhat.com] > >> Sent: Wednesday, February 7, 2018 5:53 PM > >> To: Hannes Reinecke > >> Cc: Kashyap Desai; Jens

Re: [PATCH 00/24] InfiniBand Transport (IBTRS) and Network Block Device (IBNBD)

2018-02-08 Thread Bart Van Assche
On Thu, 2018-02-08 at 18:38 +0100, Danil Kipnis wrote: > thanks for the link to the article. To the best of my understanding, > the guys suggest to authenticate the devices first and only then > authenticate the users who use the devices in order to get access to a > corporate service. They also

Re: [PATCH 1/5] blk-mq: tags: define several fields of tags as pointer

2018-02-08 Thread Bart Van Assche
On Sat, 2018-02-03 at 12:21 +0800, Ming Lei wrote: > diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h > index 61deab0b5a5a..a68323fa0c02 100644 > --- a/block/blk-mq-tag.h > +++ b/block/blk-mq-tag.h > @@ -11,10 +11,14 @@ struct blk_mq_tags { > unsigned int nr_tags; > unsigned int

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
On Thu, Feb 08, 2018 at 05:37:46PM +, Bart Van Assche wrote: > On Thu, 2018-02-08 at 09:19 -0800, t...@kernel.org wrote: > > Hello, Bart. > > > > On Thu, Feb 08, 2018 at 05:10:45PM +, Bart Van Assche wrote: > > > I think "dereferencing a pointer" means reading the memory location that >

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
Hello, Bart. On Thu, Feb 08, 2018 at 04:31:43PM +, Bart Van Assche wrote: > > That sounds more like a scsi hotplug bug than an issue in the timeout > > code unless we messed up @req pointer to begin with. > > I don't think that this is related to SCSI hotplugging: this crash does not > occur

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
Hello, Bart. On Thu, Feb 08, 2018 at 05:10:45PM +, Bart Van Assche wrote: > I think "dereferencing a pointer" means reading the memory location that > pointer points > at? Anyway, I think we both interpret the crash report in the same way, > namely that it > means that scmd->device == NULL.

[LSF/MM ATTEND] State of blk-mq I/O scheduling and next steps

2018-02-08 Thread Omar Sandoval
Hi, I'd like to attend LSF/MM to talk about the state of I/O scheduling in blk-mq. I can present some results about mq-deadline and Kyber on our production workloads. I'd also like to talk about what's next, in particular, improvements and features for Kyber. Finally, I'd like to participate in

Re: [PATCH v2] blk-throttle: fix race between blkcg_bio_issue_check and cgroup_rmdir

2018-02-08 Thread Joseph Qi
Hi Tejun, On 18/2/8 23:23, Tejun Heo wrote: > Hello, Joseph. > > On Thu, Feb 08, 2018 at 10:29:43AM +0800, Joseph Qi wrote: >> So you mean checking css->refcnt to prevent the further use of >> blkg_get? I think it makes sense. > > Yes. > >> IMO, we should use css_tryget_online instead, and

Re: [PATCH 0/4] lightnvm: base 2.0 implementation

2018-02-08 Thread Javier Gonzalez
> On 5 Feb 2018, at 13.15, Matias Bjørling wrote: > > Hi, > > A couple of patches for 2.0 support for the lightnvm subsystem. They > form the basis for integrating 2.0 support. > > For the rest of the support, Javier has code that implements report > chunk and sets up the LBA

Re: [PATCH V2] lightnvm: pblk: add padding distribution sysfs attribute

2018-02-08 Thread Matias Bjørling
On 02/06/2018 12:54 PM, hans.ml.holmb...@owltronix.com wrote: From: Hans Holmberg When pblk receives a sync, all data up to that point in the write buffer must be comitted to persistent storage, and as flash memory comes with a minimal write size there is a

Re: [PATCH 0/4] lightnvm: base 2.0 implementation

2018-02-08 Thread Matias Bjørling
On 02/08/2018 10:35 AM, Javier Gonzalez wrote: On 5 Feb 2018, at 13.15, Matias Bjørling wrote: Hi, A couple of patches for 2.0 support for the lightnvm subsystem. They form the basis for integrating 2.0 support. For the rest of the support, Javier has code that implements

Re: [PATCH v7 1/2] xfs: remove assert to check bytes returned

2018-02-08 Thread Darrick J. Wong
On Thu, Feb 08, 2018 at 12:59:47PM -0600, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues > > Since we can return less than count in case of partial direct > writes, remove the ASSERT. > > Signed-off-by: Goldwyn Rodrigues Looks ok, Reviewed-by: Darrick

RE: [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq

2018-02-08 Thread Kashyap Desai
> -Original Message- > From: Ming Lei [mailto:ming@redhat.com] > Sent: Thursday, February 8, 2018 10:23 PM > To: Hannes Reinecke > Cc: Kashyap Desai; Jens Axboe; linux-block@vger.kernel.org; Christoph > Hellwig; Mike Snitzer; linux-s...@vger.kernel.org; Arun Easi; Omar Sandoval; >

Re: [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq

2018-02-08 Thread Ming Lei
On Fri, Feb 09, 2018 at 10:28:23AM +0530, Kashyap Desai wrote: > > -Original Message- > > From: Ming Lei [mailto:ming@redhat.com] > > Sent: Thursday, February 8, 2018 10:23 PM > > To: Hannes Reinecke > > Cc: Kashyap Desai; Jens Axboe; linux-block@vger.kernel.org; Christoph > > Hellwig;

Re: [PATCH] blk: optimization for classic polling

2018-02-08 Thread Sagi Grimberg
I think it'd be simpler to have blk_poll set it back to running if need_resched is true rather than repeat this patter across all the callers: --- diff --git a/block/blk-mq.c b/block/blk-mq.c index df93102e2149..40285fe1c8ad 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3164,6 +3164,7

Re: [PATCH 3/4] lightnvm: add 2.0 geometry identification

2018-02-08 Thread Javier Gonzalez
> On 5 Feb 2018, at 13.15, Matias Bjørling wrote: > > Implement the geometry data structures for 2.0 and enable a drive > to be identified as one, including exposing the appropriate 2.0 > sysfs entries. > > Signed-off-by: Matias Bjørling > --- >

[PATCH] blk: optimization for classic polling

2018-02-08 Thread Nitesh Shetty
This removes the dependency on interrupts to wake up task. Set task state as TASK_RUNNING, if need_resched() returns true, while polling for IO completion. Earlier, polling task used to sleep, relying on interrupt to wake it up. This made some IO take very long when interrupt-coalescing is enabled

Re: [PATCH v2] blk-throttle: fix race between blkcg_bio_issue_check and cgroup_rmdir

2018-02-08 Thread Tejun Heo
Hello, Joseph. On Thu, Feb 08, 2018 at 10:29:43AM +0800, Joseph Qi wrote: > So you mean checking css->refcnt to prevent the further use of > blkg_get? I think it makes sense. Yes. > IMO, we should use css_tryget_online instead, and rightly after taking Not really. An offline css still can

Re: [PATCH] blk: optimization for classic polling

2018-02-08 Thread Keith Busch
On Sun, May 30, 2083 at 09:51:06AM +0530, Nitesh Shetty wrote: > This removes the dependency on interrupts to wake up task. Set task > state as TASK_RUNNING, if need_resched() returns true, > while polling for IO completion. > Earlier, polling task used to sleep, relying on interrupt to wake it

Re: [PATCH V2 2/8] blk-mq: introduce BLK_MQ_F_GLOBAL_TAGS

2018-02-08 Thread Bart Van Assche
On Mon, 2018-02-05 at 23:20 +0800, Ming Lei wrote: > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index 55c0a745b427..385bbec73804 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -81,6 +81,17 @@ static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx >

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
On Thu, Feb 08, 2018 at 01:09:57AM +, Bart Van Assche wrote: > On Wed, 2018-02-07 at 23:48 +, Bart Van Assche wrote: > > With this patch applied I see requests for which it seems like the timeout > > handler > > did not get invoked: [ ... ] > > I just noticed the following in the system

Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling

2018-02-08 Thread t...@kernel.org
On Thu, Feb 08, 2018 at 07:39:40AM -0800, t...@kernel.org wrote: > That sounds more like a scsi hotplug but than an issue in the timeout ^bug > code unless we messed up @req pointer to begin with. -- tejun

Re: [PATCH RESEND] blk-throttle: dispatch more sync writes in block throttle layer

2018-02-08 Thread Tejun Heo
Hello, On Thu, Feb 08, 2018 at 11:39:19AM +0800, xuejiufei wrote: > Hi Tejun, > > Could you please kindly review this patch or give some advice? I don't have anything against it but let's wait for Shaohua. Thanks. -- tejun

[PATCH v6 3/9] bcache: stop dc->writeback_rate_update properly

2018-02-08 Thread Coly Li
struct delayed_work writeback_rate_update in struct cache_dev is a delayed worker to call function update_writeback_rate() in period (the interval is defined by dc->writeback_rate_update_seconds). When a metadate I/O error happens on cache device, bcache error handling routine

[PATCH v6 2/9] bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set

2018-02-08 Thread Coly Li
In patch "bcache: fix cached_dev->count usage for bch_cache_set_error()", cached_dev_get() is called when creating dc->writeback_thread, and cached_dev_put() is called when exiting dc->writeback_thread. This modification works well unless people detach the bcache device manually by 'echo 1 >

[PATCH v6 0/9] bcache: device failure handling improvement

2018-02-08 Thread Coly Li
Hi maintainers and folks, This patch set tries to improve bcache device failure handling, includes cache device and backing device failures. The basic idea to handle failed cache device is, - Unregister cache set - Detach all backing devices which are attached to this cache set - Stop all the

[PATCH v6 1/9] bcache: fix cached_dev->count usage for bch_cache_set_error()

2018-02-08 Thread Coly Li
When bcache metadata I/O fails, bcache will call bch_cache_set_error() to retire the whole cache set. The expected behavior to retire a cache set is to unregister the cache set, and unregister all backing device attached to this cache set, then remove sysfs entries of the cache set and all

[PATCH v6 7/9] bcache: add backing_request_endio() for bi_end_io of attached backing device I/O

2018-02-08 Thread Coly Li
In order to catch I/O error of backing device, a separate bi_end_io call back is required. Then a per backing device counter can record I/O errors number and retire the backing device if the counter reaches a per backing device I/O error limit. This patch adds backing_request_endio() to bcache

[PATCH v6 6/9] bcache: fix inaccurate io state for detached bcache devices

2018-02-08 Thread Coly Li
From: Tang Junhui When we run IO in a detached device, and run iostat to shows IO status, normally it will show like bellow (Omitted some fields): Device: ... avgrq-sz avgqu-sz await r_await w_await svctm %util sdd... 15.89 0.531.820.202.23

[PATCH v6 5/9] bcache: add stop_when_cache_set_failed option to backing device

2018-02-08 Thread Coly Li
When there are too many I/O errors on cache device, current bcache code will retire the whole cache set, and detach all bcache devices. But the detached bcache devices are not stopped, which is problematic when bcache is in writeback mode. If the retired cache set has dirty data of backing

[PATCH v6 9/9] bcache: stop bcache device when backing device is offline

2018-02-08 Thread Coly Li
Currently bcache does not handle backing device failure, if backing device is offline and disconnected from system, its bcache device can still be accessible. If the bcache device is in writeback mode, I/O requests even can success if the requests hit on cache device. That is to say, when and how

[PATCH v6 8/9] bcache: add io_disable to struct cached_dev

2018-02-08 Thread Coly Li
If a bcache device is configured to writeback mode, current code does not handle write I/O errors on backing devices properly. In writeback mode, write request is written to cache device, and latter being flushed to backing device. If I/O failed when writing from cache device to the backing

[PATCH v6 4/9] bcache: add CACHE_SET_IO_DISABLE to struct cache_set flags

2018-02-08 Thread Coly Li
When too many I/Os failed on cache device, bch_cache_set_error() is called in the error handling code path to retire whole problematic cache set. If new I/O requests continue to come and take refcount dc->count, the cache set won't be retired immediately, this is a problem. Further more, there