- 04 Nov, 2017 6 commits
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Ming Lei authored
blk_insert_flush() should only insert request since run queue always follows it. In case of bypassing flush, we don't need to run queue because every blk_insert_flush() follows one run queue. Signed-off-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Jianchao Wang authored
When freeing the driver tag of the next rq with an I/O scheduler configured, we get the first entry of the list. However, this can race with requeue of a request, and we end up getting the wrong request from the head of the list. Free the driver tag of next rq before the failed one is requeued in the failure branch of queue_rq callback. Signed-off-by:
Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by:
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weiping zhang authored
blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs, otherwise policy would register fail. Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
weiping zhang <zhangweiping@didichuxing.com> Signed-off-by:
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Ming Lei authored
It is enough to just check if we can get the budget via .get_budget(). And we don't need to deal with device state change in .get_budget(). For SCSI, one issue to be fixed is that we have to call scsi_mq_uninit_cmd() to free allocated ressources if SCSI device fails to handle the request. And it isn't enough to simply call blk_mq_end_request() to do that if this request is marked as RQF_DONTPREP. Fixes: 0df21c86(scsi: implement .get_budget and .put_budget for blk-mq) Signed-off-by:
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Ming Lei authored
It is very expensive to atomic_inc/atomic_dec the host wide counter of host->busy_count, and it should have been avoided via blk-mq's mechanism of getting driver tag, which uses the more efficient way of sbitmap queue. Also we don't check atomic_read(&sdev->device_busy) in scsi_mq_get_budget() and don't run queue if the counter becomes zero, so IO hang may be caused if all requests are completed just before the current SCSI device is added to shost->starved_list. Fixes: 0df21c86(scsi: implement .get_budget and .put_budget for blk-mq) Reported-by:
Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by:
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Christoph Hellwig authored
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). Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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- 03 Nov, 2017 12 commits
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Bart Van Assche authored
blk_mq_get_tag() can modify data->ctx. This means that in the error path of blk_mq_get_request() data->ctx should be passed to blk_mq_put_ctx() instead of local_ctx. Note: since blk_mq_put_ctx() ignores its argument, this patch does not change any functionality. References: commit 1ad43c00 ("blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed") Reviewed-by:
Hannes Reinecke <hare@suse.com> Reviewed-by:
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weiping zhang authored
if blk-mq use "none" io scheduler, nr_request get a wrong value when input a number > tag_set->queue_depth. blk_mq_tag_update_depth will get the smaller one min(nr, set->queue_depth), and then q->nr_request get a wrong value. Reproduce: echo none > /sys/block/nvme0n1/queue/scheduler echo 1000000 > /sys/block/nvme0n1/queue/nr_requests cat /sys/block/nvme0n1/queue/nr_requests 1000000 Signed-off-by:
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Jens Axboe authored
We don't need to expose this. The point is that drivers select the uniform CDROM layer, if they need it, the user should not have to make a conscious decision on whether to include this separately or not. Fixes: 2a750166 ("block: Rework drivers/cdrom/Makefile") Signed-off-by:
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Christoph Hellwig authored
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:
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Christoph Hellwig authored
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:
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Christoph Hellwig authored
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 struct device. Signed-off-by:
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Christoph Hellwig authored
This helpers allows to bounce steal the uncompleted bios from a request so that they can be reissued on another path. Signed-off-by:
Sagi Grimberg <sagi@grimberg.me> Reviewed-by:
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Christoph Hellwig authored
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:
Javier González <javier@cnexlabs.com> Reviewed-by:
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Christoph Hellwig authored
Set aside a bit in the request/bio flags for driver use. Signed-off-by:
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Christoph Hellwig authored
This flag should be before the operation-specific REQ_NOUNMAP bit. Signed-off-by:
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git://git.infradead.org/nvmeJens Axboe authored
Pull NVMe changes from Christoph: "Below are the currently queue nvme updates for Linux 4.15. There are a few more things that could make it for this merge window, but I'd like to get things into linux-next, especially for the unlikely case that Linus decided to cut -rc8. Highlights: - support for SGLs in the PCIe driver (Chaitanya Kulkarni) - disable I/O schedulers for the admin queue (Israel Rukshin) - various Fibre Channel fixes and enhancements (James Smart) - various refactoring for better code sharing between transports (Sagi Grimberg and me) as well as lots of little bits from various contributors."
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Minwoo Im authored
a tiny typo fixed in a comment. Signed-off-by:
Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by:
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- 02 Nov, 2017 2 commits
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Arnd Bergmann authored
Like many storage drivers, skd uses an unsigned 32-bit number for interchanging the current time with the firmware. This will overflow in y2106 and is otherwise safe. However, the get_seconds() function is generally considered deprecated since the behavior is different between 32-bit and 64-bit architectures, and using it may indicate a bigger problem. To annotate that we've thought about this, let's add a comment here and migrate to the ktime_get_real_seconds() function that consistently returns a 64-bit number. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Arnd Bergmann authored
After the cdrom cleanup, I get randconfig warnings for some configurations: warning: (BLK_DEV_IDECD && BLK_DEV_SR) selects CDROM which has unmet direct dependencies (BLK_DEV) This adds an explicit BLK_DEV dependency for both drivers. The other drivers that select 'CDROM' already have this and don't need a change. Fixes: 2a750166 ("block: Rework drivers/cdrom/Makefile") Signed-off-by:
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- 01 Nov, 2017 20 commits
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Keith Busch authored
Signed-off-by:
Keith Busch <keith.busch@intel.com> Reviewed-by:
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James Smart authored
Below is a stack trace for an issue that was reported. What's happening is that the nvmet layer had it's controller kato timeout fire, which causes it to schedule its fatal error handler via the fatal_err_work element. The error handler is invoked, which calls the transport delete_ctrl() entry point, and as the transport tears down the controller, nvmet_sq_destroy ends up doing the final put on the ctlr causing it to enter its free routine. The ctlr free routine does a cancel_work_sync() on fatal_err_work element, which then does a flush_work and wait_for_completion. But, as the wait is in the context of the work element being flushed, its in a catch-22 and the thread hangs. [ 326.903131] nvmet: ctrl 1 keep-alive timer (15 seconds) expired! [ 326.909832] nvmet: ctrl 1 fatal error occurred! [ 327.643100] lpfc 0000:04:00.0: 0:6313 NVMET Defer ctx release xri x114 flg x2 [ 494.582064] INFO: task kworker/0:2:243 blocked for more than 120 seconds. [ 494.589638] Not tainted 4.14.0-rc1.James+ #1 [ 494.594986] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 494.603718] kworker/0:2 D 0 243 2 0x80000000 [ 494.609839] Workqueue: events nvmet_fatal_error_handler [nvmet] [ 494.616447] Call Trace: [ 494.619177] __schedule+0x28d/0x890 [ 494.623070] schedule+0x36/0x80 [ 494.626571] schedule_timeout+0x1dd/0x300 [ 494.631044] ? dequeue_task_fair+0x592/0x840 [ 494.635810] ? pick_next_task_fair+0x23b/0x5c0 [ 494.640756] wait_for_completion+0x121/0x180 [ 494.645521] ? wake_up_q+0x80/0x80 [ 494.649315] flush_work+0x11d/0x1a0 [ 494.653206] ? wake_up_worker+0x30/0x30 [ 494.657484] __cancel_work_timer+0x10b/0x190 [ 494.662249] cancel_work_sync+0x10/0x20 [ 494.666525] nvmet_ctrl_put+0xa3/0x100 [nvmet] [ 494.671482] nvmet_sq_:q+0x64/0xd0 [nvmet] [ 494.676540] nvmet_fc_delete_target_queue+0x202/0x220 [nvmet_fc] [ 494.683245] nvmet_fc_delete_target_assoc+0x6d/0xc0 [nvmet_fc] [ 494.689743] nvmet_fc_delete_ctrl+0x137/0x1a0 [nvmet_fc] [ 494.695673] nvmet_fatal_error_handler+0x30/0x40 [nvmet] [ 494.701589] process_one_work+0x149/0x360 [ 494.706064] worker_thread+0x4d/0x3c0 [ 494.710148] kthread+0x109/0x140 [ 494.713751] ? rescuer_thread+0x380/0x380 [ 494.718214] ? kthread_park+0x60/0x60 Correct by having the fc transport convert to a different workq context for the actual controller teardown which may call the cancel_work_sync. Signed-off-by:
James Smart <james.smart@broadcom.com> Reviewed-by:
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James Smart authored
When a remoteport is unregistered (connectivity lost), the following actions are taken: - the remoteport is marked DELETED - the time when dev_loss_tmo would expire is set in the remoteport - all controllers on the remoteport are reset. After a controller resets, it will stall in a RECONNECTING state waiting for one of the following: - the controller will continue to attempt reconnect per max_retries and reconnect_delay. As no remoteport connectivity, the reconnect attempt will immediately fail. If max reconnects has not been reached, a new reconnect_delay timer will be schedule. If the current time plus another reconnect_delay exceeds when dev_loss_tmo expires on the remote port, then the reconnect_delay will be shortend to schedule no later than when dev_loss_tmo expires. If max reconnect attempts are reached (e.g. ctrl_loss_tmo reached) or dev_loss_tmo ix exceeded without connectivity, the controller is deleted. - the remoteport is re-registered prior to dev_loss_tmo expiring. The resume of the remoteport will immediately attempt to reconnect each of its suspended controllers. Signed-off-by:
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James Smart authored
Transport will typically transition from LIVE to RESETTING when initially performing a reset or recovering from an error. Adding this transition allows a transport to transition to RECONNECTING when it checks/waits for connectivity then creates new transport connections and reinits the controller. Signed-off-by:
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James Smart authored
Check remoteport connectivity before initiating reconnects Signed-off-by:
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James Smart authored
Add a dev_loss_tmo value, paralleling the SCSI FC transport, for device connectivity loss. The transport initializes the value in the nvme_fc_register_remoteport() call. If the value is not set, a default of 60s is set. Add a new routine to the api, nvme_fc_set_remoteport_devloss() routine, which allows the lldd to dynamically update the value on an existing remoteport. Signed-off-by:
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James Smart authored
Clean up some of the controller state checks and add the RESETTING->RECONNECTING state transition. Specifically: - the movement of the RESETTING state change and schedule of reset_work to core doesn't work wiht nvme_fc_error_recovery setting state to RECONNECTING before attempting to reset. Remove the state change as the reset request does it. - In the rare cases where an error occurs right as we're transitioning to LIVE, defer the controller start actions. - In error handling on teardown of associations while performing initial controller creation - avoid quiesce calls on the admin_q. They are unneeded. - Add the RESETTING->RECONNECTING transition in the reset handler. Signed-off-by:
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Sagi Grimberg authored
Prevent racing controller reset and delete flows. reset_work must not ever self-requeue so flushing it suffices. Reported-by:
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Sagi Grimberg authored
instead of just queueing delete work Reported-by:
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Christoph Hellwig authored
No change in behavior except that the FC code cancels two work items a little later now. Signed-off-by:
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Christoph Hellwig authored
It is only used in two places, and some of the work done by it will be taken into common code soon. Signed-off-by:
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Christoph Hellwig authored
Move the ->delete_work and the associated helpers to common code instead of duplicating them in every driver. This also adds the missing reference get/put for the loop driver. Signed-off-by:
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Christoph Hellwig authored
No need to have two functions doing the same thing. Signed-off-by:
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James Smart authored
There's no need to wait for the full nvme_wq, which is now shared, to flush. flush only the delete_work item. Signed-off-by:
Sagi Grimberg <sgi@grimberg.me> Signed-off-by:
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Bart Van Assche authored
Instead of referring from inside drivers/cdrom/Makefile to all the drivers that use this driver, let these drivers select the cdrom driver. This change makes the cdrom build code follow the approach that is used for most other drivers, namely refer from the higher layers to the lower layer instead of from the lower layer to the higher layers. Reviewed-by:
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Ming Lei authored
SCSI restarts its queue in scsi_end_request() automatically, so we don't need to handle this case in blk-mq. Especailly any request won't be dequeued in this case, we needn't to worry about IO hang caused by restart vs. dispatch. Signed-off-by:
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Ming Lei authored
Now restart is used in the following cases, and TAG_SHARED is for SCSI only. 1) .get_budget() returns BLK_STS_RESOURCE - if resource in target/host level isn't satisfied, this SCSI device will be added in shost->starved_list, and the whole queue will be rerun (via SCSI's built-in RESTART) in scsi_end_request() after any request initiated from this host/targe is completed. Forget to mention, host level resource can't be an issue for blk-mq at all. - the same is true if resource in the queue level isn't satisfied. - if there isn't outstanding request on this queue, then SCSI's RESTART can't work(blk-mq's can't work too), and the queue will be run after SCSI_QUEUE_DELAY, and finally all starved sdevs will be handled by SCSI's RESTART when this request is finished 2) scsi_dispatch_cmd() returns BLK_STS_RESOURCE - if there isn't onprogressing request on this queue, the queue will be run after SCSI_QUEUE_DELAY - otherwise, SCSI's RESTART covers the rerun. 3) blk_mq_get_driver_tag() failed - BLK_MQ_S_TAG_WAITING covers the cross-queue RESTART for driver allocation. In one word, SCSI's built-in RESTART is enough to cover the queue rerun, and we don't need to pay special attention to TAG_SHARED wrt. restart. In my test on scsi_debug(8 luns), this patch improves IOPS by 20% ~ 30% when running I/O on these 8 luns concurrently. Aslo Roman Pen reported the current RESTART is very expensive especialy when there are lots of LUNs attached in one host, such as in his test, RESTART causes half of IOPS be cut. Fixes: https://marc.info/?l=linux-kernel&m=150832216727524&w=2 Fixes: 6d8c6c0f ("blk-mq: Restart a single queue if tag sets are shared") Signed-off-by:
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Ming Lei authored
We need to tell blk-mq to reserve resources before queuing one request, so implement these two callbacks. Then blk-mq can avoid to dequeue request too early, and IO merging can be improved a lot. Signed-off-by:
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Ming Lei authored
In the following patch, we will implement scsi_get_budget() which need to call scsi_prep_state_check() when rq isn't dequeued yet. Signed-off-by:
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Ming Lei authored
SCSI devices use host-wide tagset, and the shared driver tag space is often quite big. However, there is also a queue depth for each lun( .cmd_per_lun), which is often small, for example, on both lpfc and qla2xxx, .cmd_per_lun is just 3. So lots of requests may stay in sw queue, and we always flush all belonging to same hw queue and dispatch them all to driver. Unfortunately it is easy to cause queue busy because of the small .cmd_per_lun. Once these requests are flushed out, they have to stay in hctx->dispatch, and no bio merge can happen on these requests, and sequential IO performance is harmed. This patch introduces blk_mq_dequeue_from_ctx for dequeuing a request from a sw queue, so that we can dispatch them in scheduler's way. We can then avoid dequeueing too many requests from sw queue, since we don't flush ->dispatch completely. This patch improves dispatching from sw queue by using the .get_budget and .put_budget callbacks. Reviewed-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
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