user/sven/linux.git/block, branch v4.19.54

block, bfq: increase idling for weight-raised queues

2019-06-15T09:54:10Z

[ Upstream commit 778c02a236a8728bb992de10ed1f12c0be5b7b0e ] If a sync bfq_queue has a higher weight than some other queue, and remains temporarily empty while in service, then, to preserve the bandwidth share of the queue, it is necessary to plug I/O dispatching until a new request arrives for the queue. In addition, a timeout needs to be set, to avoid waiting for ever if the process associated with the queue has actually finished its I/O. Even with the above timeout, the device is however not fed with new I/O for a while, if the process has finished its I/O. If this happens often, then throughput drops and latencies grow. For this reason, the timeout is kept rather low: 8 ms is the current default. Unfortunately, such a low value may cause, on the opposite end, a violation of bandwidth guarantees for a process that happens to issue new I/O too late. The higher the system load, the higher the probability that this happens to some process. This is a problem in scenarios where service guarantees matter more than throughput. One important case are weight-raised queues, which need to be granted a very high fraction of the bandwidth. To address this issue, this commit lower-bounds the plugging timeout for weight-raised queues to 20 ms. This simple change provides relevant benefits. For example, on a PLEXTOR PX-256M5S, with which gnome-terminal starts in 0.6 seconds if there is no other I/O in progress, the same applications starts in - 0.8 seconds, instead of 1.2 seconds, if ten files are being read sequentially in parallel - 1 second, instead of 2 seconds, if, in parallel, five files are being read sequentially, and five more files are being written sequentially Tested-by: Holger Hoffstätte Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Valente Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq: move cancel of requeue_work into blk_mq_release

2019-06-15T09:54:06Z

[ Upstream commit fbc2a15e3433058582e5635aabe48a3011a644a8 ] With holding queue's kobject refcount, it is safe for driver to schedule requeue. However, blk_mq_kick_requeue_list() may be called after blk_sync_queue() is done because of concurrent requeue activities, then requeue work may not be completed when freeing queue, and kernel oops is triggered. So moving the cancel of requeue_work into blk_mq_release() for avoiding race between requeue and freeing queue. Cc: Dongli Zhang Cc: James Smart Cc: Bart Van Assche Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen , Cc: Christoph Hellwig , Cc: James E . J . Bottomley , Reviewed-by: Bart Van Assche Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Tested-by: James Smart Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: sed-opal: fix IOC_OPAL_ENABLE_DISABLE_MBR

2019-05-31T13:46:24Z

[ Upstream commit 78bf47353b0041865564deeed257a54f047c2fdc ] The implementation of IOC_OPAL_ENABLE_DISABLE_MBR handled the value opal_mbr_data.enable_disable incorrectly: enable_disable is expected to be one of OPAL_MBR_ENABLE(0) or OPAL_MBR_DISABLE(1). enable_disable was passed directly to set_mbr_done and set_mbr_enable_disable where is was interpreted as either OPAL_TRUE(1) or OPAL_FALSE(0). The end result was that calling IOC_OPAL_ENABLE_DISABLE_MBR with OPAL_MBR_ENABLE actually disabled the shadow MBR and vice versa. This patch adds correct conversion from OPAL_MBR_DISABLE/ENABLE to OPAL_FALSE/TRUE. The change affects existing programs using IOC_OPAL_ENABLE_DISABLE_MBR but this is typically used only once when setting up an Opal drive. Acked-by: Jon Derrick Reviewed-by: Christoph Hellwig Reviewed-by: Scott Bauer Signed-off-by: David Kozub Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix use-after-free on gendisk

2019-05-31T13:46:18Z

[ Upstream commit 2c88e3c7ec32d7a40cc7c9b4a487cf90e4671bdd ] commit 2da78092dda "block: Fix dev_t minor allocation lifetime" specifically moved blk_free_devt(dev->devt) call to part_release() to avoid reallocating device number before the device is fully shutdown. However, it can cause use-after-free on gendisk in get_gendisk(). We use md device as example to show the race scenes: Process1 Worker Process2 md_free blkdev_open del_gendisk add delete_partition_work_fn() to wq __blkdev_get get_gendisk put_disk disk_release kfree(disk) find part from ext_devt_idr get_disk_and_module(disk) cause use after free delete_partition_work_fn put_device(part) part_release remove part from ext_devt_idr Before is removed from ext_devt_idr by delete_partition_work_fn(), we can find the devt and then access gendisk by hd_struct pointer. But, if we access the gendisk after it have been freed, it can cause in use-after-freeon gendisk in get_gendisk(). We fix this by adding a new helper blk_invalidate_devt() in delete_partition() and del_gendisk(). It replaces hd_struct pointer in idr with value 'NULL', and deletes the entry from idr in part_release() as we do now. Thanks to Jan Kara for providing the solution and more clear comments for the code. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: Al Viro Reviewed-by: Bart Van Assche Reviewed-by: Keith Busch Reviewed-by: Jan Kara Suggested-by: Jan Kara Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bfq: update internal depth state when queue depth changes

2019-05-16T17:41:17Z

commit 77f1e0a52d26242b6c2dba019f6ebebfb9ff701e upstream A previous commit moved the shallow depth and BFQ depth map calculations to be done at init time, moving it outside of the hotter IO path. This potentially causes hangs if the users changes the depth of the scheduler map, by writing to the 'nr_requests' sysfs file for that device. Add a blk-mq-sched hook that allows blk-mq to inform the scheduler if the depth changes, so that the scheduler can update its internal state. Signed-off-by: Eric Wheeler Tested-by: Kai Krakow Reported-by: Paolo Valente Fixes: f0635b8a416e ("bfq: calculate shallow depths at init time") Signed-off-by: Jens Axboe Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

block: pass no-op callback to INIT_WORK().

2019-05-08T05:21:51Z

[ Upstream commit 2e3c18d0ada16f145087b2687afcad1748c0827c ] syzbot is hitting flush_work() warning caused by commit 4d43d395fed12463 ("workqueue: Try to catch flush_work() without INIT_WORK().") [1]. Although that commit did not expect INIT_WORK(NULL) case, calling flush_work() without setting a valid callback should be avoided anyway. Fix this problem by setting a no-op callback instead of NULL. [1] https://syzkaller.appspot.com/bug?id=e390366bc48bc82a7c668326e0663be3b91cbd29 Signed-off-by: Tetsuo Handa Reported-and-tested-by: syzbot Cc: Tejun Heo Signed-off-by: Jens Axboe [sl: rename blk_timeout_work] Signed-off-by: Sasha Levin

block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx

2019-05-08T05:21:49Z

[ Upstream commit b9a1ff504b9492ad6beb7d5606e0e3365d4d8499 ] kfree() can leak the hctx->fq->flush_rq field. Reviewed-by: Ming Lei Signed-off-by: Shenghui Wang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-iolatency: #include "blk.h"

2019-04-20T07:15:58Z

[ Upstream commit 373e915cd8e84544609eced57a44fbc084f8d60f ] This patch avoids that the following warning is reported when building with W=1: block/blk-iolatency.c:734:5: warning: no previous prototype for 'blk_iolatency_init' [-Wmissing-prototypes] Cc: Josef Bacik Fixes: d70675121546 ("block: introduce blk-iolatency io controller") # v4.19 Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: do not leak memory in bio_copy_user_iov()

2019-04-17T06:38:51Z

commit a3761c3c91209b58b6f33bf69dd8bb8ec0c9d925 upstream. When bio_add_pc_page() fails in bio_copy_user_iov() we should free the page we just allocated otherwise we are leaking it. Cc: linux-block@vger.kernel.org Cc: Linus Torvalds Cc: stable@vger.kernel.org Reviewed-by: Chaitanya Kulkarni Signed-off-by: Jérôme Glisse Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block, bfq: fix in-service-queue check for queue merging

2019-04-05T20:33:12Z

[ Upstream commit 058fdecc6de7cdecbf4c59b851e80eb2d6c5295f ] When a new I/O request arrives for a bfq_queue, say Q, bfq checks whether that request is close to (a) the head request of some other queue waiting to be served, or (b) the last request dispatched for the in-service queue (in case Q itself is not the in-service queue) If a queue, say Q2, is found for which the above condition holds, then bfq merges Q and Q2, to hopefully get a more sequential I/O in the resulting merged queue, and thus a possibly higher throughput. Case (b) is checked by comparing the new request for Q with the last request dispatched, assuming that the latter necessarily belonged to the in-service queue. Unfortunately, this assumption is no longer always correct, since commit d0edc2473be9 ("block, bfq: inject other-queue I/O into seeky idle queues on NCQ flash"). When the assumption does not hold, queues that must not be merged may be merged, causing unexpected loss of control on per-queue service guarantees. This commit solves this problem by adding an extra field, which stores the actual last request dispatched for the in-service queue, and by using this new field to correctly check case (b). Signed-off-by: Paolo Valente Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin