kernel/linux.git/block, branch v5.10.7

blk-iocost: fix NULL iocg deref from racing against initialization

2021-01-12T19:18:23+00:00

commit d16baa3f1453c14d680c5fee01cd122a22d0e0ce upstream. When initializing iocost for a queue, its rqos should be registered before the blkcg policy is activated to allow policy data initiailization to lookup the associated ioc. This unfortunately means that the rqos methods can be called on bios before iocgs are attached to all existing blkgs. While the race is theoretically possible on ioc_rqos_throttle(), it mostly happened in ioc_rqos_merge() due to the difference in how they lookup ioc. The former determines it from the passed in @rqos and then bails before dereferencing iocg if the looked up ioc is disabled, which most likely is the case if initialization is still in progress. The latter looked up ioc by dereferencing the possibly NULL iocg making it a lot more prone to actually triggering the bug. * Make ioc_rqos_merge() use the same method as ioc_rqos_throttle() to look up ioc for consistency. * Make ioc_rqos_throttle() and ioc_rqos_merge() test for NULL iocg before dereferencing it. * Explain the danger of NULL iocgs in blk_iocost_init(). Signed-off-by: Tejun Heo Reported-by: Jonathan Lemon Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

scsi: block: Do not accept any requests while suspended

2021-01-12T19:18:17+00:00

[ Upstream commit 52abca64fd9410ea6c9a3a74eab25663b403d7da ] blk_queue_enter() accepts BLK_MQ_REQ_PM requests independent of the runtime power management state. Now that SCSI domain validation no longer depends on this behavior, modify the behavior of blk_queue_enter() as follows: - Do not accept any requests while suspended. - Only process power management requests while suspending or resuming. Submitting BLK_MQ_REQ_PM requests to a device that is runtime suspended causes runtime-suspended devices not to resume as they should. The request which should cause a runtime resume instead gets issued directly, without resuming the device first. Of course the device can't handle it properly, the I/O fails, and the device remains suspended. The problem is fixed by checking that the queue's runtime-PM status isn't RPM_SUSPENDED before allowing a request to be issued, and queuing a runtime-resume request if it is. In particular, the inline blk_pm_request_resume() routine is renamed blk_pm_resume_queue() and the code is unified by merging the surrounding checks into the routine. If the queue isn't set up for runtime PM, or there currently is no restriction on allowed requests, the request is allowed. Likewise if the BLK_MQ_REQ_PM flag is set and the status isn't RPM_SUSPENDED. Otherwise a runtime resume is queued and the request is blocked until conditions are more suitable. [ bvanassche: modified commit message and removed Cc: stable because without the previous patches from this series this patch would break parallel SCSI domain validation + introduced queue_rpm_status() ] Link: https://lore.kernel.org/r/20201209052951.16136-9-bvanassche@acm.org Cc: Jens Axboe Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Can Guo Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Reported-and-tested-by: Martin Kepplinger Reviewed-by: Hannes Reinecke Reviewed-by: Can Guo Signed-off-by: Alan Stern Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT

2021-01-12T19:18:17+00:00

[ Upstream commit a4d34da715e3cb7e0741fe603dcd511bed067e00 ] Remove flag RQF_PREEMPT and BLK_MQ_REQ_PREEMPT since these are no longer used by any kernel code. Link: https://lore.kernel.org/r/20201209052951.16136-8-bvanassche@acm.org Cc: Can Guo Cc: Stanley Chu Cc: Alan Stern Cc: Ming Lei Cc: Rafael J. Wysocki Cc: Martin Kepplinger Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Jens Axboe Reviewed-by: Can Guo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: block: Introduce BLK_MQ_REQ_PM

2021-01-12T19:18:15+00:00

[ Upstream commit 0854bcdcdec26aecdc92c303816f349ee1fba2bc ] Introduce the BLK_MQ_REQ_PM flag. This flag makes the request allocation functions set RQF_PM. This is the first step towards removing BLK_MQ_REQ_PREEMPT. Link: https://lore.kernel.org/r/20201209052951.16136-3-bvanassche@acm.org Cc: Alan Stern Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Cc: Can Guo Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Jens Axboe Reviewed-by: Can Guo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

block: add debugfs stanza for QUEUE_FLAG_NOWAIT

2021-01-12T19:18:14+00:00

[ Upstream commit dc30432605bbbd486dfede3852ea4d42c40a84b4 ] This was missed in 021a24460dc2. Leads to the numeric value of QUEUE_FLAG_NOWAIT (i.e. 29) showing up in /sys/kernel/debug/block/*/state. Fixes: 021a24460dc28e7412aecfae89f60e1847e685c0 Cc: Konstantin Khlebnikov Cc: Mike Snitzer Cc: Christoph Hellwig Cc: Jens Axboe Signed-off-by: Andres Freund Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

scsi: block: Fix a race in the runtime power management code

2021-01-06T13:56:50+00:00

commit fa4d0f1992a96f6d7c988ef423e3127e613f6ac9 upstream. With the current implementation the following race can happen: * blk_pre_runtime_suspend() calls blk_freeze_queue_start() and blk_mq_unfreeze_queue(). * blk_queue_enter() calls blk_queue_pm_only() and that function returns true. * blk_queue_enter() calls blk_pm_request_resume() and that function does not call pm_request_resume() because the queue runtime status is RPM_ACTIVE. * blk_pre_runtime_suspend() changes the queue status into RPM_SUSPENDING. Fix this race by changing the queue runtime status into RPM_SUSPENDING before switching q_usage_counter to atomic mode. Link: https://lore.kernel.org/r/20201209052951.16136-2-bvanassche@acm.org Fixes: 986d413b7c15 ("blk-mq: Enable support for runtime power management") Cc: Ming Lei Cc: Rafael J. Wysocki Cc: stable Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Jens Axboe Acked-by: Alan Stern Acked-by: Stanley Chu Co-developed-by: Can Guo Signed-off-by: Can Guo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

Merge tag 'block-5.10-2020-12-05' of git://git.kernel.dk/linux-block

2020-12-05T22:45:30+00:00

Pull block fix from Jens Axboe: "Single fix for an issue with chunk_sectors and stacked devices" * tag 'block-5.10-2020-12-05' of git://git.kernel.dk/linux-block: block: use gcd() to fix chunk_sectors limit stacking

Merge tag 'for-5.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2020-12-04T21:28:39+00:00

Pull device mapper fixes from Mike Snitzer: - Fix DM's bio splitting changes that were made during v5.9. This restores splitting in terms of varied per-target ti->max_io_len rather than use block core's single stacked 'chunk_sectors' limit. - Like DM crypt, update DM integrity to not use crypto drivers that have CRYPTO_ALG_ALLOCATES_MEMORY set. - Fix DM writecache target's argument parsing and status display. - Remove needless BUG() from dm writecache's persistent_memory_claim() - Remove old gcc workaround in DM cache target's block_div() for ARM link errors now that gcc >= 4.9 is required. - Fix RCU locking in dm_blk_report_zones and dm_dax_zero_page_range. - Remove old, and now frowned upon, BUG_ON(in_interrupt()) in dm_table_event(). - Remove invalid sparse annotations from dm_prepare_ioctl() and dm_unprepare_ioctl(). * tag 'for-5.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: remove invalid sparse __acquires and __releases annotations dm: fix double RCU unlock in dm_dax_zero_page_range() error path dm: fix IO splitting dm writecache: remove BUG() and fail gracefully instead dm table: Remove BUG_ON(in_interrupt()) dm: fix bug with RCU locking in dm_blk_report_zones Revert "dm cache: fix arm link errors with inline" dm writecache: fix the maximum number of arguments dm writecache: advance the number of arguments when reporting max_age dm integrity: don't use drivers that have CRYPTO_ALG_ALLOCATES_MEMORY

dm: fix IO splitting

2020-12-04T19:53:15+00:00

Commit 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") caused a couple regressions: 1) Using lcm_not_zero() when stacking chunk_sectors was a bug because chunk_sectors must reflect the most limited of all devices in the IO stack. 2) DM targets that set max_io_len but that do _not_ provide an .iterate_devices method no longer had there IO split properly. And commit 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") also caused a regression where DM no longer supported varied (per target) IO splitting. The implication being the potential for severely reduced performance for IO stacks that use a DM target like dm-cache to hide performance limitations of a slower device (e.g. one that requires 4K IO splitting). Coming full circle: Fix all these issues by discontinuing stacking chunk_sectors up using ti->max_io_len in dm_calculate_queue_limits(), add optional chunk_sectors override argument to blk_max_size_offset() and update DM's max_io_len() to pass ti->max_io_len to its blk_max_size_offset() call. Passing in an optional chunk_sectors override to blk_max_size_offset() allows for code reuse of block's centralized calculation for max IO size based on provided offset and split boundary. Fixes: 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") Fixes: 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") Cc: stable@vger.kernel.org Reported-by: John Dorminy Reported-by: Bruce Johnston Reported-by: Kirill Tkhai Reviewed-by: John Dorminy Signed-off-by: Mike Snitzer Reviewed-by: Jens Axboe

block: use gcd() to fix chunk_sectors limit stacking

2020-12-01T18:02:55+00:00

commit 22ada802ede8 ("block: use lcm_not_zero() when stacking chunk_sectors") broke chunk_sectors limit stacking. chunk_sectors must reflect the most limited of all devices in the IO stack. Otherwise malformed IO may result. E.g.: prior to this fix, ->chunk_sectors = lcm_not_zero(8, 128) would result in blk_max_size_offset() splitting IO at 128 sectors rather than the required more restrictive 8 sectors. And since commit 07d098e6bbad ("block: allow 'chunk_sectors' to be non-power-of-2") care must be taken to properly stack chunk_sectors to be compatible with the possibility that a non-power-of-2 chunk_sectors may be stacked. This is why gcd() is used instead of reverting back to using min_not_zero(). Fixes: 22ada802ede8 ("block: use lcm_not_zero() when stacking chunk_sectors") Fixes: 07d098e6bbad ("block: allow 'chunk_sectors' to be non-power-of-2") Reported-by: John Dorminy Reported-by: Bruce Johnston Signed-off-by: Mike Snitzer Reviewed-by: John Dorminy Cc: stable@vger.kernel.org Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe