Re: [PATCH V8 00/14] mmc: Add Command Queue support

+ Bartlomiej [...] > So my conclusion is, let's start a as you suggested, by not completing > the request in ->done() as to maintain existing behavior. Then we can > address optimizations on top, which very likely will involve doing > changes to host drivers as well.

Re: [bug report] regression bisected to "block: Make most scsi_req_init() calls implicit"

On Mon, Oct 23, 2017 at 3:08 PM, Bart Van Assche wrote: > On Mon, 2017-10-23 at 09:41 -0600, dann frazier wrote: >> (gdb) list *(sg_io+0x120) >> 0x084e71a8 is in sg_io (./include/linux/uaccess.h:113). >> 108 static inline unsigned long >> 109

Re: [bug report] regression bisected to "block: Make most scsi_req_init() calls implicit"

On Mon, 2017-10-23 at 09:41 -0600, dann frazier wrote: > (gdb) list *(sg_io+0x120) > 0x084e71a8 is in sg_io (./include/linux/uaccess.h:113). > 108 static inline unsigned long > 109 _copy_from_user(void *to, const void __user *from, unsigned long n) > 110 { > 111 unsigned

Re: [PATCH 16/17] nvme: implement multipath access to nvme subsystems

static inline bool nvme_req_needs_retry(struct request *req) { if (blk_noretry_request(req)) @@ -143,6 +204,11 @@ static inline bool nvme_req_needs_retry(struct request *req) void nvme_complete_rq(struct request *req) { if (unlikely(nvme_req(req)->status &&

Re: [PATCH 16/17] nvme: implement multipath access to nvme subsystems

On Mon, Oct 23, 2017 at 06:32:47PM +0300, Sagi Grimberg wrote: >> struct nvme_queue *nvmeq = hctx->driver_data; >> + printk_ratelimited("%s: called\n", __func__); >> + > > This must be a left-over... Indeed, it is a left-over debug statement..

Re: [PATCH 1/1] [RFC] blk-mq: fix queue stalling on shared hctx restart

Hi Ming, On Fri, Oct 20, 2017 at 3:39 PM, Ming Lei wrote: > On Wed, Oct 18, 2017 at 12:22:06PM +0200, Roman Pen wrote: >> Hi all, >> >> the patch below fixes queue stalling when shared hctx marked for restart >> (BLK_MQ_S_SCHED_RESTART bit) but q->shared_hctx_restart stays

Re: [bug report] regression bisected to "block: Make most scsi_req_init() calls implicit"

On Fri, Oct 20, 2017 at 11:30:55PM +, Bart Van Assche wrote: > On Fri, 2017-10-20 at 16:54 -0600, dann frazier wrote: > > hey, > > I'm seeing a regression when executing 'dmraid -r -c' in an arm64 > > QEMU guest, which I've bisected to the following commit: > > > > ca18d6f7 "block: Make

Re: [PATCH 16/17] nvme: implement multipath access to nvme subsystems

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 7735571ffc9a..bbece5edabff 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1050,6 +1050,8 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag) { struct nvme_queue *nvmeq =

Re: [PATCH 1/1] [RFC] blk-mq: fix queue stalling on shared hctx restart

On Fri, Oct 20, 2017 at 10:05 PM, Bart Van Assche wrote: > On Fri, 2017-10-20 at 11:39 +0200, Roman Penyaev wrote: >> But what bothers me is these looong loops inside blk_mq_sched_restart(), >> and since you are the author of the original 6d8c6c0f97ad ("blk-mq: Restart >>

[PATCH 01/17] block: move REQ_NOWAIT

This flag should be before the operation-specific REQ_NOUNMAP bit. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn --- include/linux/blk_types.h | 4 ++--

[PATCH 11/17] nvme: get rid of nvme_ctrl_list

Use the core chrdev code to set up the link between the character device and the nvme controller. This allows us to get rid of the global list of all controllers, and also ensures that we have both a reference to the controller and the transport module before the open method of the character

[PATCH 12/17] nvme: check for a live controller in nvme_dev_open

This is a much more sensible check than just the admin queue. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Johannes Thumshirn --- drivers/nvme/host/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff

[PATCH 07/17] block: add a poll_fn callback to struct request_queue

That we we can also poll non blk-mq queues. Mostly needed for the NVMe multipath code, but could also be useful elsewhere. Signed-off-by: Christoph Hellwig --- block/blk-core.c | 11 +++ block/blk-mq.c | 14 +-

[PATCH 09/17] nvme: simplify nvme_open

Now that we are protected against lookup vs free races for the namespace by using kref_get_unless_zero we don't need the hack of NULLing out the disk private data during removal. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Johannes

nvme multipath support V5

Hi all, this series adds support for multipathing, that is accessing nvme namespaces through multiple controllers to the nvme core driver. It is a very thin and efficient implementation that relies on close cooperation with other bits of the nvme driver, and few small and simple block helpers.

[PATCH 15/17] nvme: track shared namespaces

Introduce a new struct nvme_ns_head that holds information about an actual namespace, unlike struct nvme_ns, which only holds the per-controller namespace information. For private namespaces there is a 1:1 relation of the two, but for shared namespaces this lets us discover all the paths to it.

[PATCH 05/17] block: don't look at the struct device dev_t in disk_devt

The hidden gendisks introduced in the next patch need to keep the dev field in their struct device empty so that udev won't try to create block device nodes for them. To support that rewrite disk_devt to look at the major and first_minor fields in the gendisk itself instead of looking into the

[PATCH 17/17] nvme: also expose the namespace identification sysfs files for mpath nodes

We do this by adding a helper that returns the ns_head for a device that can belong to either the per-controller or per-subsystem block device nodes, and otherwise reuse all the existing code. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch

[PATCH 08/17] nvme: use kref_get_unless_zero in nvme_find_get_ns

For kref_get_unless_zero to protect against lookup vs free races we need to use it in all places where we aren't guaranteed to already hold a reference. There is no such guarantee in nvme_find_get_ns, so switch to kref_get_unless_zero in this function. Signed-off-by: Christoph Hellwig

[PATCH 10/17] nvme: switch controller refcounting to use struct device

Instead of allocating a separate struct device for the character device handle embedd it into struct nvme_ctrl and use it for the main controller refcounting. This removes double refcounting and gets us an automatic reference for the character device operations. We keep ctrl->device as a pointer

[PATCH 16/17] nvme: implement multipath access to nvme subsystems

This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the

[PATCH 14/17] nvme: introduce a nvme_ns_ids structure

This allows us to manage the various uniqueue namespace identifiers together instead needing various variables and arguments. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Reviewed-by: Sagi Grimberg --- drivers/nvme/host/core.c

[PATCH 06/17] block: introduce GENHD_FL_HIDDEN

With this flag a driver can create a gendisk that can be used for I/O submission inside the kernel, but which is not registered as user facing block device. This will be useful for the NVMe multipath implementation. Signed-off-by: Christoph Hellwig --- block/genhd.c | 57

[PATCH 03/17] block: provide a direct_make_request helper

This helper allows reinserting a bio into a new queue without much overhead, but requires all queue limits to be the same for the upper and lower queues, and it does not provide any recursion preventions. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg

[PATCH 02/17] block: add REQ_DRV bit

Set aside a bit in the request/bio flags for driver use. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn --- include/linux/blk_types.h | 5 + 1 file

[PATCH 04/17] block: add a blk_steal_bios helper

This helpers allows to bounce steal the uncompleted bios from a request so that they can be reissued on another path. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg --- block/blk-core.c | 20 include/linux/blkdev.h | 2 ++

Re: [PATCH V8 00/14] mmc: Add Command Queue support

On 20/10/17 15:30, Adrian Hunter wrote: > On 19/10/17 14:44, Adrian Hunter wrote: >> On 18/10/17 09:16, Adrian Hunter wrote: >>> On 11/10/17 16:58, Ulf Hansson wrote: On 11 October 2017 at 14:58, Adrian Hunter wrote: > On 11/10/17 15:13, Ulf Hansson wrote: >>

Re: [PATCH v2] block: fix peeking requests during PM

On Fri, Oct 20, 2017 at 04:45:23PM +0200, Christoph Hellwig wrote: > We need to look for an active PM request until the next softbarrier > instead of looking for the first non-PM request. Otherwise any cause > of request reordering might starve the PM request(s). Hi Christoph, Could you share

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

On Sun, Oct 22, 2017 at 01:47:54PM +, Israel Rukshin wrote: > Currently, blk_mq_tagset_iter() iterate over initial hctx tags only. > In case scheduler is used, it doesn't iterate the hctx scheduler tags > and the static request aren't been updated. > For example, while using NVMe over Fabrics

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index c81b40e..c290de0 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -322,6 +322,22 @@ int blk_mq_tagset_iter(struct blk_mq_tag_set *set, void *data,   }   } +    for (i = 0; i < set->nr_hw_queues; i++) { +   

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

@@ -441,6 +442,8 @@ static int blk_mq_sched_alloc_tags(struct request_queue *q, if (!hctx->sched_tags) return -ENOMEM; + set->sched_tags[hctx_idx] = hctx->sched_tags; + ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); if (ret)

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

On Mon, Oct 23, 2017 at 10:27:29AM +0300, Sagi Grimberg wrote: > Note that it does introduce a new spinlock to our hot-path, but given > the current over-allocation scheme with schedulers, its probably better > off. We could look into llists if it matters.

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

Currently, blk_mq_tagset_iter() iterate over initial hctx tags only. In case scheduler is used, it doesn't iterate the hctx scheduler tags and the static request aren't been updated. For example, while using NVMe over Fabrics RDMA host, this cause us not to reinit the scheduler requests and

Re: [PATCH v2 4/4] lockdep: Assign a lock_class per gendisk used for wait_for_completion()

On Sun, Oct 22, 2017 at 11:36:30PM -0700, Christoph Hellwig wrote: > On Mon, Oct 23, 2017 at 08:53:35AM +0900, Byungchul Park wrote: > > On Fri, Oct 20, 2017 at 07:44:51AM -0700, Christoph Hellwig wrote: > > > The Subject prefix for this should be "block:". > > > > > > > @@ -945,7 +945,7 @@ int

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

On Sun, 2017-10-22 at 13:47 +, Israel Rukshin wrote: > @@ -441,6 +442,8 @@ static int blk_mq_sched_alloc_tags(struct request_queue > *q, > if (!hctx->sched_tags) > return -ENOMEM; > > + set->sched_tags[hctx_idx] = hctx->sched_tags; > + > ret =

Re: [PATCH v2 4/4] lockdep: Assign a lock_class per gendisk used for wait_for_completion()

On Mon, Oct 23, 2017 at 08:53:35AM +0900, Byungchul Park wrote: > On Fri, Oct 20, 2017 at 07:44:51AM -0700, Christoph Hellwig wrote: > > The Subject prefix for this should be "block:". > > > > > @@ -945,7 +945,7 @@ int submit_bio_wait(struct bio *bio) > > > { > > > struct submit_bio_ret ret; >

Re: nvme multipath support V4

Guan, If per-controller block device nodes are hidden, how can the user-space tools such as multipath-tools and nvme-cli (if it supports) know status of each path of the multipath device? if at all, the path state is reflected on the controller class device node, not on the namespace block

Re: [PATCH 9/9] bsg: split handling of SCSI CDBs vs transport requeues

On Mon, Oct 23, 2017 at 02:16:03AM -0400, Martin K. Petersen wrote: > > Benjamin, > > >> Not sure it's worth it especially now that Martin has merged the patch. > > > > He did? I only saw a mail that he picked patches 2-5. So all the bsg > > changes are still open I think. > > Yes, I expected

Re: [PATCH] blk-mq: Iterate also over sched_tags requests at blk_mq_tagset_iter()

On Sun, Oct 22, 2017 at 09:32:00PM +0300, Sagi Grimberg wrote: > >> Currently, blk_mq_tagset_iter() iterate over initial hctx tags only. >> In case scheduler is used, it doesn't iterate the hctx scheduler tags >> and the static request aren't been updated. >> For example, while using NVMe over

Re: [PATCH 9/9] bsg: split handling of SCSI CDBs vs transport requeues

Benjamin, >> Not sure it's worth it especially now that Martin has merged the patch. > > He did? I only saw a mail that he picked patches 2-5. So all the bsg > changes are still open I think. Yes, I expected the bsg bits to go through Jens' tree. -- Martin K. Petersen Oracle Linux