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* blk-mq: fix sysfs inflight counterOmar Sandoval2018-04-264-5/+40
| | | | | | | | | | When the blk-mq inflight implementation was added, /proc/diskstats was converted to use it, but /sys/block/$dev/inflight was not. Fix it by adding another helper to count in-flight requests by data direction. Fixes: f299b7c7a9de ("blk-mq: provide internal in-flight variant") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: count allocated but not started requests in iostats inflightOmar Sandoval2018-04-261-12/+9
| | | | | | | | | | | | | | | In the legacy block case, we increment the counter right after we allocate the request, not when the driver handles it. In both the legacy and blk-mq cases, part_inc_in_flight() is called from blk_account_io_start() right after we've allocated the request. blk-mq only considers requests started requests as inflight, but this is inconsistent with the legacy definition and the intention in the code. This removes the started condition and instead counts all allocated requests. Fixes: f299b7c7a9de ("blk-mq: provide internal in-flight variant") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Revert "blk-mq: remove code for dealing with remapping queue"Ming Lei2018-04-251-3/+31
| | | | | | | | | | | | | | | | | | This reverts commit 37c7c6c76d431dd7ef9c29d95f6052bd425f004c. Turns out some drivers(most are FC drivers) may not use managed IRQ affinity, and has their customized .map_queues meantime, so still keep this code for avoiding regression. Reported-by: Laurence Oberman <loberman@redhat.com> Tested-by: Laurence Oberman <loberman@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: Ewan Milne <emilne@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: mq: Add some minor doc for core structsLinus Walleij2018-04-251-0/+3
| | | | | | | | | | As it came up in discussion on the mailing list that the semantic meaning of 'blk_mq_ctx' and 'blk_mq_hw_ctx' isn't completely obvious to everyone, let's add some minimal kerneldoc for a starter. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: init root blkcg_gq under lockJiang Biao2018-04-191-6/+11
| | | | | | | | | | | | | | The initializing of q->root_blkg is currently outside of queue lock and rcu, so the blkg may be destroied before the initializing, which may cause dangling/null references. On the other side, the destroys of blkg are protected by queue lock or rcu. Put the initializing inside the queue lock and rcu to make it safer. Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> CC: Tejun Heo <tj@kernel.org> CC: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: small fix on comment in blkcg_init_queueJiang Biao2018-04-191-5/+1
| | | | | | | | | | | | The comment before blkg_create() in blkcg_init_queue() was moved from blkcg_activate_policy() by commit ec13b1d6f0a0457312e615, but it does not suit for the new context. Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> CC: Tejun Heo <tj@kernel.org> CC: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: don't hold blkcg lock when deactivating policyJiang Biao2018-04-181-5/+0
| | | | | | | | | | | | | | | | As described in the comment of blkcg_activate_policy(), *Update of each blkg is protected by both queue and blkcg locks so that holding either lock and testing blkcg_policy_enabled() is always enough for dereferencing policy data.* with queue lock held, there is no need to hold blkcg lock in blkcg_deactivate_policy(). Similar case is in blkcg_activate_policy(), which has removed holding of blkcg lock in commit 4c55f4f9ad3001ac1fefdd8d8ca7641d18558e23. Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> CC: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bfq-iosched: ensure to clear bic/bfqq pointers when preparing requestJens Axboe2018-04-171-1/+9
| | | | | | | | | | | | | | | | Even if we don't have an IO context attached to a request, we still need to clear the priv[0..1] pointers, as they could be pointing to previously used bic/bfqq structures. If we don't do so, we'll either corrupt memory on dispatching a request, or cause an imbalance in counters. Inspired by a fix from Kees. Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler") Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: start request gstate with gen 1Jianchao Wang2018-04-162-0/+11
| | | | | | | | | | | | | | | | | | | | | | rq->gstate and rq->aborted_gstate both are zero before rqs are allocated. If we have a small timeout, when the timer fires, there could be rqs that are never allocated, and also there could be rq that has been allocated but not initialized and started. At the moment, the rq->gstate and rq->aborted_gstate both are 0, thus the blk_mq_terminate_expired will identify the rq is timed out and invoke .timeout early. For scsi, this will cause scsi_times_out to be invoked before the scsi_cmnd is not initialized, scsi_cmnd->device is still NULL at the moment, then we will get crash. Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Martin Steigerwald <Martin@Lichtvoll.de> Cc: stable@vger.kernel.org Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: do not use interruptible wait anywhereAlan Jenkins2018-04-141-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When blk_queue_enter() waits for a queue to unfreeze, or unset the PREEMPT_ONLY flag, do not allow it to be interrupted by a signal. The PREEMPT_ONLY flag was introduced later in commit 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably"). Note the SCSI device is resumed asynchronously, i.e. after un-freezing userspace tasks. So that commit exposed the bug as a regression in v4.15. A mysterious SIGBUS (or -EIO) sometimes happened during the time the device was being resumed. Most frequently, there was no kernel log message, and we saw Xorg or Xwayland killed by SIGBUS.[1] [1] E.g. https://bugzilla.redhat.com/show_bug.cgi?id=1553979 Without this fix, I get an IO error in this test: # dd if=/dev/sda of=/dev/null iflag=direct & \ while killall -SIGUSR1 dd; do sleep 0.1; done & \ echo mem > /sys/power/state ; \ sleep 5; killall dd # stop after 5 seconds The interruptible wait was added to blk_queue_enter in commit 3ef28e83ab15 ("block: generic request_queue reference counting"). Before then, the interruptible wait was only in blk-mq, but I don't think it could ever have been correct. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: stable@vger.kernel.org Signed-off-by: Alan Jenkins <alan.christopher.jenkins@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: Revert "blk-mq: reimplement blk_mq_hw_queue_mapped"Ming Lei2018-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 127276c6ce5a30fcc806b7fe53015f4f89b62956. When all CPUs of one hw queue become offline, there still may have IOs not completed from this hctx. But blk_mq_hw_queue_mapped() is called in blk_mq_queue_tag_busy_iter(), which is used for iterating request in timeout handler, timeout event will be missed on the inactive hctx, then request may never be completed. Also the replementation of blk_mq_hw_queue_mapped() doesn't match the helper's name any more, and it should have been named as blk_mq_hw_queue_active(). Even other callers need further verification about this reimplemenation. So revert this patch now, and we can improve hw queue activate/inactivate event after adequent researching and test. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Reported-by: Jens Axboe <axboe@kernel.dk> Fixes: 127276c6ce5a30fcc ("blk-mq: reimplement blk_mq_hw_queue_mapped") Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: Avoid that submitting a bio concurrently with device removal ↵Bart Van Assche2018-04-101-6/+29
| | | | | | | | | | | | | | | | triggers a crash Because blkcg_exit_queue() is now called from inside blk_cleanup_queue() it is no longer safe to access cgroup information during or after the blk_cleanup_queue() call. Hence protect the generic_make_request_checks() call with blk_queue_enter() / blk_queue_exit(). Reported-by: Ming Lei <ming.lei@redhat.com> Fixes: a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: remove code for dealing with remapping queueMing Lei2018-04-101-31/+3
| | | | | | | | | | | | | | | | | | Firstly, from commit 4b855ad37194 ("blk-mq: Create hctx for each present CPU), blk-mq doesn't remap queue any more after CPU topo is changed. Secondly, set->nr_hw_queues can't be bigger than nr_cpu_ids, and now we map all possible CPUs to hw queues, so at least one CPU is mapped to each hctx. So queue mapping has became static and fixed just like percpu variable, and we don't need to handle queue remapping any more. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: reimplement blk_mq_hw_queue_mappedMing Lei2018-04-101-1/+1
| | | | | | | | | | | | | Now the actual meaning of queue mapped is that if there is any online CPU mapped to this hctx, so implement blk_mq_hw_queue_mapped() in this way. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: don't check queue mapped in __blk_mq_delay_run_hw_queue()Ming Lei2018-04-101-3/+0
| | | | | | | | | | | | | | | | | | | | | | There are several reasons for removing the check: 1) blk_mq_hw_queue_mapped() returns true always now since each hctx may be mapped by one CPU at least 2) when there isn't any online CPU mapped to this hctx, there won't be any IO queued to this CPU, blk_mq_run_hw_queue() only runs queue if there is IO queued to this hctx 3) If __blk_mq_delay_run_hw_queue() is called by blk_mq_delay_run_hw_queue(), which is run from blk_mq_dispatch_rq_list() or scsi_mq_get_budget(), and the hctx to be handled has to be mapped. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: remove blk_mq_delay_queue()Ming Lei2018-04-102-29/+2
| | | | | | | | | | | No driver uses this interface any more, so remove it. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: introduce blk_mq_hw_queue_first_cpu() to figure out first cpuMing Lei2018-04-101-12/+11
| | | | | | | | | | | | | This patch introduces helper of blk_mq_hw_queue_first_cpu() for figuring out the hctx's first cpu, and code duplication can be avoided. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: avoid to write intermediate result to hctx->next_cpuMing Lei2018-04-101-8/+9
| | | | | | | | | | | | | This patch figures out the final selected CPU, then writes it to hctx->next_cpu once, then we can avoid to intermediate next cpu observed from other dispatch paths. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: don't keep offline CPUs mapped to hctx 0Ming Lei2018-04-101-5/+0
| | | | | | | | | | | | | | | | | | | | | From commit 4b855ad37194 ("blk-mq: Create hctx for each present CPU), blk-mq doesn't remap queue after CPU topo is changed, that said when some of these offline CPUs become online, they are still mapped to hctx 0, then hctx 0 may become the bottleneck of IO dispatch and completion. This patch sets up the mapping from the beginning, and aligns to queue mapping for PCI device (blk_mq_pci_map_queues()). Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Cc: stable@vger.kernel.org Fixes: 4b855ad37194 ("blk-mq: Create hctx for each present CPU) Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: make sure that correct hctx->next_cpu is setMing Lei2018-04-101-0/+2
| | | | | | | | | | | | | | | | | | From commit 20e4d81393196 (blk-mq: simplify queue mapping & schedule with each possisble CPU), one hctx can be mapped from all offline CPUs, then hctx->next_cpu can be set as wrong. This patch fixes this issue by making hctx->next_cpu pointing to the first CPU in hctx->cpumask if all CPUs in hctx->cpumask are offline. Cc: Stefan Haberland <sth@linux.vnet.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Fixes: 20e4d81393196 ("blk-mq: simplify queue mapping & schedule with each possisble CPU") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: order getting budget and driver tagMing Lei2018-04-101-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch orders getting budget and driver tag by making sure to acquire driver tag after budget is got, this way can help to avoid the following race: 1) before dispatch request from scheduler queue, get one budget first, then dequeue a request, call it request A. 2) in another IO path for dispatching request B which is from hctx->dispatch, driver tag is got, then try to get budget in blk_mq_dispatch_rq_list(), unfortunately the budget is held by request A. 3) meantime blk_mq_dispatch_rq_list() is called for dispatching request A, and try to get driver tag first, unfortunately no driver tag is available because the driver tag is held by request B 4) both two IO pathes can't move on, and IO stall is caused. This issue can be observed when running dbench on USB storage. This patch fixes this issue by always getting budget before getting driver tag. Cc: stable@vger.kernel.org Fixes: de1482974080ec9e ("blk-mq: introduce .get_budget and .put_budget in blk_mq_ops") Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-blockLinus Torvalds2018-04-0517-426/+695
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block layer updates from Jens Axboe: "It's a pretty quiet round this time, which is nice. This contains: - series from Bart, cleaning up the way we set/test/clear atomic queue flags. - series from Bart, fixing races between gendisk and queue registration and removal. - set of bcache fixes and improvements from various folks, by way of Michael Lyle. - set of lightnvm updates from Matias, most of it being the 1.2 to 2.0 transition. - removal of unused DIO flags from Nikolay. - blk-mq/sbitmap memory ordering fixes from Omar. - divide-by-zero fix for BFQ from Paolo. - minor documentation patches from Randy. - timeout fix from Tejun. - Alpha "can't write a char atomically" fix from Mikulas. - set of NVMe fixes by way of Keith. - bsg and bsg-lib improvements from Christoph. - a few sed-opal fixes from Jonas. - cdrom check-disk-change deadlock fix from Maurizio. - various little fixes, comment fixes, etc from various folks" * tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits) blk-mq: Directly schedule q->timeout_work when aborting a request blktrace: fix comment in blktrace_api.h lightnvm: remove function name in strings lightnvm: pblk: remove some unnecessary NULL checks lightnvm: pblk: don't recover unwritten lines lightnvm: pblk: implement 2.0 support lightnvm: pblk: implement get log report chunk lightnvm: pblk: rename ppaf* to addrf* lightnvm: pblk: check for supported version lightnvm: implement get log report chunk helpers lightnvm: make address conversions depend on generic device lightnvm: add support for 2.0 address format lightnvm: normalize geometry nomenclature lightnvm: complete geo structure with maxoc* lightnvm: add shorten OCSSD version in geo lightnvm: add minor version to generic geometry lightnvm: simplify geometry structure lightnvm: pblk: refactor init/exit sequences lightnvm: Avoid validation of default op value lightnvm: centralize permission check for lightnvm ioctl ...
| * blk-mq: Directly schedule q->timeout_work when aborting a requestTejun Heo2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Request abortion is performed by overriding deadline to now and scheduling timeout handling immediately. For the latter part, the code was using mod_timer(timeout, 0) which can't guarantee that the timer runs afterwards. Let's schedule the underlying work item directly instead. This fixes the hangs during probing reported by Sitsofe but it isn't yet clear to me how the failure can happen reliably if it's just the above described race condition. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sitsofe Wheeler <sitsofe@gmail.com> Reported-by: Meelis Roos <mroos@linux.ee> Fixes: 358f70da49d7 ("blk-mq: make blk_abort_request() trigger timeout path") Cc: stable@vger.kernel.org # v4.16 Link: http://lkml.kernel.org/r/CALjAwxh-PVYFnYFCJpGOja+m5SzZ8Sa4J7ohxdK=r8NyOF-EMA@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.LRH.2.21.1802261049140.4893@math.ut.ee Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq: Allow PCI vector offset for mapping queuesKeith Busch2018-03-271-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The PCI interrupt vectors intended to be associated with a queue may not start at 0; a driver may allocate pre_vectors for special use. This patch adds an offset parameter so blk-mq may find the intended affinity mask and updates all drivers using this API accordingly. Cc: Don Brace <don.brace@microsemi.com> Cc: <qla2xxx-upstream@qlogic.com> Cc: <linux-scsi@vger.kernel.org> Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block, bfq: lower-bound the estimated peak rate to 1Paolo Valente2018-03-262-2/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a storage device handled by BFQ happens to be slower than 7.5 KB/s for a certain amount of time (in the order of a second), then the estimated peak rate of the device, maintained in BFQ, becomes equal to 0. The reason is the limited precision with which the rate is represented (details on the range of representable values in the comments introduced by this commit). This leads to a division-by-zero error where the estimated peak rate is used as divisor. Such a type of failure has been reported in [1]. This commit addresses this issue by: 1. Lower-bounding the estimated peak rate to 1 2. Adding and improving comments on the range of rates representable [1] https://www.spinics.net/lists/kernel/msg2739205.html Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * Fix slab name "biovec-(1<<(21-12))"Mikulas Patocka2018-03-211-2/+2
| | | | | | | | | | | | | | | | | | I'm getting a slab named "biovec-(1<<(21-12))". It is caused by unintended expansion of the macro BIO_MAX_PAGES. This patch renames it to biovec-max. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Change a rcu_read_{lock,unlock}_sched() pair into ↵Bart Van Assche2018-03-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rcu_read_{lock,unlock}() scsi_device_quiesce() uses synchronize_rcu() to guarantee that the effect of blk_set_preempt_only() will be visible for percpu_ref_tryget() calls that occur after the queue unfreeze by using the approach explained in https://lwn.net/Articles/573497/. The rcu read lock and unlock calls in blk_queue_enter() form a pair with the synchronize_rcu() call in scsi_device_quiesce(). Both scsi_device_quiesce() and blk_queue_enter() must either use regular RCU or RCU-sched. Since neither the RCU-protected code in blk_queue_enter() nor blk_queue_usage_counter_release() sleeps, regular RCU protection is sufficient. Note: scsi_device_quiesce() does not have to be modified since it already uses synchronize_rcu(). Reported-by: Tejun Heo <tj@kernel.org> Fixes: 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Martin Steigerwald <martin@lichtvoll.de> Cc: stable@vger.kernel.org # v4.15 Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: bio_check_eod() needs to consider partitionsChristoph Hellwig2018-03-171-53/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | bio_check_eod() should check partition size not the whole disk if bio->bi_partno is non-zero. Do this by moving the call to bio_check_eod() into blk_partition_remap(). Based on an earlier patch from Jiufei Xue. Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index") Reported-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq-debugfs: Show more request state informationBart Van Assche2018-03-171-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq") blk_rq_is_complete() only reports whether or not a request has completed for legacy queues. Hence modify the blk-mq-debugfs code such that it shows the blk-mq request state again. Fixes: 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()Joseph Qi2018-03-161-16/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've triggered a WARNING in blk_throtl_bio() when throttling writeback io, which complains blkg->refcnt is already 0 when calling blkg_get(), and then kernel crashes with invalid page request. After investigating this issue, we've found it is caused by a race between blkcg_bio_issue_check() and cgroup_rmdir(), which is described below: writeback kworker cgroup_rmdir cgroup_destroy_locked kill_css css_killed_ref_fn css_killed_work_fn offline_css blkcg_css_offline blkcg_bio_issue_check rcu_read_lock blkg_lookup spin_trylock(q->queue_lock) blkg_destroy spin_unlock(q->queue_lock) blk_throtl_bio spin_lock_irq(q->queue_lock) ... spin_unlock_irq(q->queue_lock) rcu_read_unlock Since rcu can only prevent blkg from releasing when it is being used, the blkg->refcnt can be decreased to 0 during blkg_destroy() and schedule blkg release. Then trying to blkg_get() in blk_throtl_bio() will complains the WARNING. And then the corresponding blkg_put() will schedule blkg release again, which result in double free. This race is introduced by commit ae1188963611 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()"). Before this commit, it will lookup first and then try to lookup/create again with queue_lock. Since revive this logic is a bit drastic, so fix it by only offlining pd during blkcg_css_offline(), and move the rest destruction (especially blkg_put()) into blkcg_css_free(), which should be the right way as discussed. Fixes: ae1188963611 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()") Reported-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: sed-opal: fix u64 short atom lengthJonas Rabenstein2018-03-161-7/+4
| | | | | | | | | | | | | | | | The length must be given as bytes and not as 4 bit tuples. Reviewed-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * bsg: split handling of SCSI CDBs vs transport requeuesChristoph Hellwig2018-03-132-198/+222
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current BSG design tries to shoe-horn the transport-specific passthrough commands into the overall framework for SCSI passthrough requests. This has a couple problems: - each passthrough queue has to set the QUEUE_FLAG_SCSI_PASSTHROUGH flag despite not dealing with SCSI commands at all. Because of that these queues could also incorrectly accept SCSI commands from in-kernel users or through the legacy SCSI_IOCTL_SEND_COMMAND ioctl. - the real SCSI bsg queues also incorrectly accept bsg requests of the BSG_SUB_PROTOCOL_SCSI_TRANSPORT type - the bsg transport code is almost unredable because it tries to reuse different SCSI concepts for its own purpose. This patch instead adds a new bsg_ops structure to handle the two cases differently, and thus solves all of the above problems. Another side effect is that the bsg-lib queues also don't need to embedd a struct scsi_request anymore. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * bsg-lib: remove bsg_job.reqChristoph Hellwig2018-03-131-8/+6
| | | | | | | | | | | | | | | | | | | | | | Users of the bsg-lib interface should only use the bsg_job data structure and not know about implementation details of it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * bsg-lib: introduce a timeout field in struct bsg_jobChristoph Hellwig2018-03-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | The zfcp driver wants to know the timeout for a bsg job, so add a field to struct bsg_job for it in preparation of not exposing the request to the bsg-lib users. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Suppress kernel-doc warnings triggered by blk-zoned.cBart Van Assche2018-03-091-2/+2
| | | | | | | | | | | | | | | | | | | | Avoid that building with W=1 causes the kernel-doc tool to complain about undocumented function arguments for the blk-zoned.c source file. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Move the queue_flag_*() functions from a public into a private header ↵Bart Van Assche2018-03-081-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | file This patch helps to avoid that new code gets introduced in block drivers that manipulates queue flags without holding the queue lock when that lock should be held. Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Use blk_queue_flag_*() in drivers instead of queue_flag_*()Bart Van Assche2018-03-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch has been generated as follows: for verb in set_unlocked clear_unlocked set clear; do replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \ $(git grep -lw queue_flag_${verb} drivers block/bsg*) done Except for protecting all queue flag changes with the queue lock this patch does not change any functionality. Cc: Mike Snitzer <snitzer@redhat.com> Cc: Shaohua Li <shli@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Protect queue flag changes with the queue lockBart Van Assche2018-03-082-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the queue flags may be changed concurrently from multiple contexts after a queue becomes visible in sysfs, make these changes safe by protecting these with the queue lock. Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()Bart Van Assche2018-03-085-49/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce functions that modify the queue flags and that protect these modifications with the request queue lock. Except for moving one wake_up_all() call from inside to outside a critical section, this patch does not change any functionality. Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Use the queue_flag_*() functions instead of open-coding theseBart Van Assche2018-03-084-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Except for changing the atomic queue flag manipulations that are protected by the queue lock into non-atomic manipulations, this patch does not change any functionality. Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: sed-opal: fix response string extractionJonas Rabenstein2018-03-061-3/+23
| | | | | | | | | | | | | | | | | | | | | | Tokens are prefixed by a variable length of bytes. If a bytestring is not stored in an tiny or short atom, we have to skip more than one byte in order to have the actual bytes not prefixed by the bytes describing the actual length of the string. Acked-by: Jonathan Derrick <jonathan.derrick@intel.com> Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Fix a race between request queue removal and the block cgroup controllerBart Van Assche2018-02-282-7/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid that the following race can occur: blk_cleanup_queue() blkcg_print_blkgs() spin_lock_irq(lock) (1) spin_lock_irq(blkg->q->queue_lock) (2,5) q->queue_lock = &q->__queue_lock (3) spin_unlock_irq(lock) (4) spin_unlock_irq(blkg->q->queue_lock) (6) (1) take driver lock; (2) busy loop for driver lock; (3) override driver lock with internal lock; (4) unlock driver lock; (5) can take driver lock now; (6) but unlock internal lock. This change is safe because only the SCSI core and the NVME core keep a reference on a request queue after having called blk_cleanup_queue(). Neither driver accesses any of the removed data structures between its blk_cleanup_queue() and blk_put_queue() calls. Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Fix a race between the cgroup code and request queue initializationBart Van Assche2018-02-281-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Initialize the request queue lock earlier such that the following race can no longer occur: blk_init_queue_node() blkcg_print_blkgs() blk_alloc_queue_node (1) q->queue_lock = &q->__queue_lock (2) blkcg_init_queue(q) (3) spin_lock_irq(blkg->q->queue_lock) (4) q->queue_lock = lock (5) spin_unlock_irq(blkg->q->queue_lock) (6) (1) allocate an uninitialized queue; (2) initialize queue_lock to its default internal lock; (3) initialize blkcg part of request queue, which will create blkg and then insert it to blkg_list; (4) traverse blkg_list and find the created blkg, and then take its queue lock, here it is the default *internal lock*; (5) *race window*, now queue_lock is overridden with *driver specified lock*; (6) now unlock *driver specified lock*, not the locked *internal lock*, unlock balance breaks. The changes in this patch are as follows: - Move the .queue_lock initialization from blk_init_queue_node() into blk_alloc_queue_node(). - Only override the .queue_lock pointer for legacy queues because it is not useful for blk-mq queues to override this pointer. - For all all block drivers that initialize .queue_lock explicitly, change the blk_alloc_queue() call in the driver into a blk_alloc_queue_node() call and remove the explicit .queue_lock initialization. Additionally, initialize the spin lock that will be used as queue lock earlier if necessary. Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Add 'lock' as third argument to blk_alloc_queue_node()Bart Van Assche2018-02-282-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: clear ctx pending bit under ctx lockOmar Sandoval2018-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we insert a request, we set the software queue pending bit while holding the software queue lock. However, we clear it outside of the lock, so it's possible that a concurrent insert could reset the bit after we clear it but before we empty the request list. Afterwards, the bit would still be set but the software queue wouldn't have any requests in it, leading us to do a spurious run in the future. This is mostly a benign/theoretical issue, but it makes the following change easier to justify. Signed-off-by: Omar Sandoval <osandov@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq-debugfs: Show zone locking informationBart Van Assche2018-02-281-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When debugging the ZBC code in the mq-deadline scheduler it is very important to know which zones are locked and which zones are not locked. Hence this patch that exports the zone locking information through debugfs. Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq-debugfs: Reorder queue show and store methodsBart Van Assche2018-02-281-65/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | Make sure that the queue show and store methods are contiguous and also that these appear in alphabetical order. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge tag 'char-misc-4.17-rc1' of ↵Linus Torvalds2018-04-041-8/+11
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc updates from Greg KH: "Here is the big set of char/misc driver patches for 4.17-rc1. There are a lot of little things in here, nothing huge, but all important to the different hardware types involved: - thunderbolt driver updates - parport updates (people still care...) - nvmem driver updates - mei updates (as always) - hwtracing driver updates - hyperv driver updates - extcon driver updates - ... and a handful of even smaller driver subsystem and individual driver updates All of these have been in linux-next with no reported issues" * tag 'char-misc-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (149 commits) hwtracing: Add HW tracing support menu intel_th: Add ACPI glue layer intel_th: Allow forcing host mode through drvdata intel_th: Pick up irq number from resources intel_th: Don't touch switch routing in host mode intel_th: Use correct method of finding hub intel_th: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate stm class: Make dummy's master/channel ranges configurable stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate MAINTAINERS: Bestow upon myself the care for drivers/hwtracing hv: add SPDX license id to Kconfig hv: add SPDX license to trace Drivers: hv: vmbus: do not mark HV_PCIE as perf_device Drivers: hv: vmbus: respect what we get from hv_get_synint_state() /dev/mem: Avoid overwriting "err" in read_mem() eeprom: at24: use SPDX identifier instead of GPL boiler-plate eeprom: at24: simplify the i2c functionality checking eeprom: at24: fix a line break eeprom: at24: tweak newlines eeprom: at24: refactor at24_probe() ...
| * | block, char_dev: Use correct format specifier for unsigned intsSrivatsa S. Bhat2018-03-151-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | register_blkdev() and __register_chrdev_region() treat the major number as an unsigned int. So print it the same way to avoid absurd error statements such as: "... major requested (-1) is greater than the maximum (511) ..." (and also fix off-by-one bugs in the error prints). While at it, also update the comment describing register_blkdev(). Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | treewide: simplify Kconfig dependencies for removed archsArnd Bergmann2018-03-261-1/+1
|/ / | | | | | | | | | | | | | | | | | | A lot of Kconfig symbols have architecture specific dependencies. In those cases that depend on architectures we have already removed, they can be omitted. Acked-by: Kalle Valo <kvalo@codeaurora.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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