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2020-06-05Merge tag 'for-5.8/dm-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - The largest change for this cycle is the DM zoned target's metadata version 2 feature that adds support for pairing regular block devices with a zoned device to ease the performance impact associated with finite random zones of zoned device. The changes came in three batches: the first prepared for and then added the ability to pair a single regular block device, the second was a batch of fixes to improve zoned's reclaim heuristic, and the third removed the limitation of only adding a single additional regular block device to allow many devices. Testing has shown linear scaling as more devices are added. - Add new emulated block size (ebs) target that emulates a smaller logical_block_size than a block device supports The primary use-case is to emulate "512e" devices that have 512 byte logical_block_size and 4KB physical_block_size. This is useful to some legacy applications that otherwise wouldn't be able to be used on 4K devices because they depend on issuing IO in 512 byte granularity. - Add discard interfaces to DM bufio. First consumer of the interface is the dm-ebs target that makes heavy use of dm-bufio. - Fix DM crypt's block queue_limits stacking to not truncate logic_block_size. - Add Documentation for DM integrity's status line. - Switch DMDEBUG from a compile time config option to instead use dynamic debug via pr_debug. - Fix DM multipath target's hueristic for how it manages "queue_if_no_path" state internally. DM multipath now avoids disabling "queue_if_no_path" unless it is actually needed (e.g. in response to configure timeout or explicit "fail_if_no_path" message). This fixes reports of spurious -EIO being reported back to userspace application during fault tolerance testing with an NVMe backend. Added various dynamic DMDEBUG messages to assist with debugging queue_if_no_path in the future. - Add a new DM multipath "Historical Service Time" Path Selector. - Fix DM multipath's dm_blk_ioctl() to switch paths on IO error. - Improve DM writecache target performance by using explicit cache flushing for target's single-threaded usecase and a small cleanup to remove unnecessary test in persistent_memory_claim. - Other small cleanups in DM core, dm-persistent-data, and DM integrity. * tag 'for-5.8/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (62 commits) dm crypt: avoid truncating the logical block size dm mpath: add DM device name to Failing/Reinstating path log messages dm mpath: enhance queue_if_no_path debugging dm mpath: restrict queue_if_no_path state machine dm mpath: simplify __must_push_back dm zoned: check superblock location dm zoned: prefer full zones for reclaim dm zoned: select reclaim zone based on device index dm zoned: allocate zone by device index dm zoned: support arbitrary number of devices dm zoned: move random and sequential zones into struct dmz_dev dm zoned: per-device reclaim dm zoned: add metadata pointer to struct dmz_dev dm zoned: add device pointer to struct dm_zone dm zoned: allocate temporary superblock for tertiary devices dm zoned: convert to xarray dm zoned: add a 'reserved' zone flag dm zoned: improve logging messages for reclaim dm zoned: avoid unnecessary device recalulation for secondary superblock dm zoned: add debugging message for reading superblocks ...
2020-06-05dm crypt: avoid truncating the logical block sizeEric Biggers
queue_limits::logical_block_size got changed from unsigned short to unsigned int, but it was forgotten to update crypt_io_hints() to use the new type. Fix it. Fixes: ad6bf88a6c19 ("block: fix an integer overflow in logical block size") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm mpath: add DM device name to Failing/Reinstating path log messagesMike Snitzer
When there are many DM multipath devices it really helps to have additional context for which DM device a failed or reinstated path is part of. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm mpath: enhance queue_if_no_path debuggingMike Snitzer
Add more DMDEBUG that shows arguments passed and caller, and another that shows state of related flags at end of queue_if_no_path(). Also add queue_if_no_path DMDEBUG to multipath_resume(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm mpath: restrict queue_if_no_path state machineMike Snitzer
Do not allow saving disabled queue_if_no_path if already saved as enabled; implies multiple suspends (which shouldn't ever happen). Log if this unlikely scenario is ever triggered. Also, only write MPATHF_SAVED_QUEUE_IF_NO_PATH during presuspend or if "fail_if_no_path" message. MPATHF_SAVED_QUEUE_IF_NO_PATH is no longer always modified, e.g.: even if queue_if_no_path()'s save_old_value argument wasn't set. This just implies a bit tighter control over the management of MPATHF_SAVED_QUEUE_IF_NO_PATH. Side-effect is multipath_resume() doesn't reset MPATHF_QUEUE_IF_NO_PATH unless MPATHF_SAVED_QUEUE_IF_NO_PATH was set (during presuspend); and at that time the MPATHF_SAVED_QUEUE_IF_NO_PATH bit gets cleared. So MPATHF_SAVED_QUEUE_IF_NO_PATH's use is much more narrow in scope. Last, but not least, do _not_ disable queue_if_no_path during noflush suspend. There is no need/benefit to saving off queue_if_no_path via MPATHF_SAVED_QUEUE_IF_NO_PATH and clearing MPATHF_QUEUE_IF_NO_PATH for noflush suspend -- by avoiding this needless queue_if_no_path flag churn there is less potential for MPATHF_QUEUE_IF_NO_PATH to get lost. Which avoids potential for IOs to be errored back up to userspace during DM multipath's handling of path failures. That said, this last change papers over a reported issue concerning request-based dm-multipath's interaction with blk-mq, relative to suspend and resume: multipath_endio is being called _before_ multipath_resume. This should never happen if DM suspend's blk_mq_quiesce_queue() + dm_wait_for_completion() is genuinely waiting for all inflight blk-mq requests to complete. Similarly: drivers/md/dm.c:__dm_resume() clearly calls dm_table_resume_targets() _before_ dm_start_queue()'s blk_mq_unquiesce_queue() is called. If the queue isn't even restarted until after multipath_resume(); the BIG question that still needs answering is: how can multipath_end_io beat multipath_resume in a race!? Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm mpath: simplify __must_push_backMike Snitzer
Remove micro-optimization that infers device is between presuspend and resume (was done purely to avoid call to dm_noflush_suspending, which isn't expensive anyway). Remove flags argument since they are no longer checked. And remove must_push_back_bio() since it was simply a call to __must_push_back(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: check superblock locationHannes Reinecke
When specifying several devices the superblock location must be checked to ensure the devices are specified in the correct order. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: prefer full zones for reclaimHannes Reinecke
Prefer full zones when selecting the next zone for reclaim. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: select reclaim zone based on device indexHannes Reinecke
per-device reclaim should select zones on that device only. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: allocate zone by device indexHannes Reinecke
When allocating a zone, pass in an indicator on which device the zone should be allocated; this increases performance for a multi-device setup because reclaim will now allocate zones on the device for which reclaim is running. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: support arbitrary number of devicesHannes Reinecke
Remove the hard-coded limit of two devices and support an unlimited number of additional zoned devices. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: move random and sequential zones into struct dmz_devHannes Reinecke
Random and sequential zones should be part of the respective device structure to make arbitration between devices possible. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: per-device reclaimHannes Reinecke
Instead of having one reclaim workqueue for the entire set we should be allocating a reclaim workqueue per device; doing so will reduce contention and should boost performance for a multi-device setup. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add metadata pointer to struct dmz_devHannes Reinecke
Add a metadata pointer within struct dmz_dev and use it as argument for blkdev_report_zones() instead of the metadata itself. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add device pointer to struct dm_zoneHannes Reinecke
Add a pointer, to the containing device, within struct dm_zone and kill dmz_zone_to_dev(). Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: allocate temporary superblock for tertiary devicesHannes Reinecke
Checking the tertiary superblock just consists of validating UUIDs, crcs, and the generation number; it doesn't have contents which would be required during the actual operation. So allocate a temporary superblock when checking tertiary devices to avoid having to store it together with the 'real' superblocks. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: convert to xarrayHannes Reinecke
The zones array is getting really large, and large arrays tend to wreak havoc with the CPU caches. So convert it to xarray to become more cache friendly. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix leak in dmz_insert Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add a 'reserved' zone flagHannes Reinecke
Instead of counting the number of reserved zones in dmz_free_zone(), mark the zone as 'reserved' during allocation and simplify dmz_free_zone(). Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: improve logging messages for reclaimHannes Reinecke
Instead of just reporting the errno, add some more verbose debugging message in the reclaim path. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: avoid unnecessary device recalulation for secondary superblockHannes Reinecke
The secondary superblock must reside on the same device as the primary superblock, so there is no need to re-calculate the device. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add debugging message for reading superblocksHannes Reinecke
Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm ebs: use dm_bufio_forget_buffersMikulas Patocka
Use dm_bufio_forget_buffers instead of a block-by-block loop that calls dm_bufio_forget. dm_bufio_forget_buffers is faster than the loop because it searches for used buffers using rb-tree. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm bufio: introduce forget_buffer_lockedMikulas Patocka
Introduce a function forget_buffer_locked that forgets a range of buffers. It is more efficient than calling forget_buffer in a loop. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm bufio: clean up rbtree block orderingMikulas Patocka
dm-bufio uses unnatural ordering in the rb-tree - blocks with smaller numbers were put to the right node and blocks with bigger numbers were put to the left node. Reverse that logic so that it's natural. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-04dm bufio: delete unused and inefficient dm_bufio_discard_buffersMikulas Patocka
There is no user for this interface. If in future it is needed it can be reimplemented to walk the rbtree of buffers instead of doing block-by-block lookups. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-02Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "On top of the core changes, here are the block driver changes for this merge window: - NVMe changes: - NVMe over Fibre Channel protocol updates, which also reach over to drivers/scsi/lpfc (James Smart) - namespace revalidation support on the target (Anthony Iliopoulos) - gcc zero length array fix (Arnd Bergmann) - nvmet cleanups (Chaitanya Kulkarni) - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg) - use a SRQ per completion vector (Max Gurtovoy) - fix handling of runtime changes to the queue count (Weiping Zhang) - t10 protection information support for nvme-rdma and nvmet-rdma (Israel Rukshin and Max Gurtovoy) - target side AEN improvements (Chaitanya Kulkarni) - various fixes and minor improvements all over, icluding the nvme part of the lpfc driver" - Floppy code cleanup series (Willy, Denis) - Floppy contention fix (Jiri) - Loop CONFIGURE support (Martijn) - bcache fixes/improvements (Coly, Joe, Colin) - q->queuedata cleanups (Christoph) - Get rid of ioctl_by_bdev (Christoph, Stefan) - md/raid5 allocation fixes (Coly) - zero length array fixes (Gustavo) - swim3 task state fix (Xu)" * tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits) bcache: configure the asynchronous registertion to be experimental bcache: asynchronous devices registration bcache: fix refcount underflow in bcache_device_free() bcache: Convert pr_<level> uses to a more typical style bcache: remove redundant variables i and n lpfc: Fix return value in __lpfc_nvme_ls_abort lpfc: fix axchg pointer reference after free and double frees lpfc: Fix pointer checks and comments in LS receive refactoring nvme: set dma alignment to qword nvmet: cleanups the loop in nvmet_async_events_process nvmet: fix memory leak when removing namespaces and controllers concurrently nvmet-rdma: add metadata/T10-PI support nvmet: add metadata support for block devices nvmet: add metadata/T10-PI support nvme: add Metadata Capabilities enumerations nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len nvmet: rename nvmet_rw_len to nvmet_rw_data_len nvmet: add metadata characteristics for a namespace nvme-rdma: add metadata/T10-PI support nvme-rdma: introduce nvme_rdma_sgl structure ...
2020-06-02Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Core block changes that have been queued up for this release: - Remove dead blk-throttle and blk-wbt code (Guoqing) - Include pid in blktrace note traces (Jan) - Don't spew I/O errors on wouldblock termination (me) - Zone append addition (Johannes, Keith, Damien) - IO accounting improvements (Konstantin, Christoph) - blk-mq hardware map update improvements (Ming) - Scheduler dispatch improvement (Salman) - Inline block encryption support (Satya) - Request map fixes and improvements (Weiping) - blk-iocost tweaks (Tejun) - Fix for timeout failing with error injection (Keith) - Queue re-run fixes (Douglas) - CPU hotplug improvements (Christoph) - Queue entry/exit improvements (Christoph) - Move DMA drain handling to the few drivers that use it (Christoph) - Partition handling cleanups (Christoph)" * tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits) block: mark bio_wouldblock_error() bio with BIO_QUIET blk-wbt: rename __wbt_update_limits to wbt_update_limits blk-wbt: remove wbt_update_limits blk-throttle: remove tg_drain_bios blk-throttle: remove blk_throtl_drain null_blk: force complete for timeout request blk-mq: drain I/O when all CPUs in a hctx are offline blk-mq: add blk_mq_all_tag_iter blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx blk-mq: use BLK_MQ_NO_TAG in more places blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG blk-mq: move more request initialization to blk_mq_rq_ctx_init blk-mq: simplify the blk_mq_get_request calling convention blk-mq: remove the bio argument to ->prepare_request nvme: force complete cancelled requests blk-mq: blk-mq: provide forced completion method block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds block: blk-crypto-fallback: remove redundant initialization of variable err block: reduce part_stat_lock() scope block: use __this_cpu_add() instead of access by smp_processor_id() ...
2020-06-02mm: remove the pgprot argument to __vmallocChristoph Hellwig
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> [hyperv] Acked-by: Gao Xiang <xiang@kernel.org> [erofs] Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Wei Liu <wei.liu@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02md: remove __clear_page_buffers and use attach/detach_page_privateGuoqing Jiang
After introduction attach/detach_page_private in pagemap.h, we can remove the duplicated code and call the new functions. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Song Liu <song@kernel.org> Link: http://lkml.kernel.org/r/20200517214718.468-3-guoqing.jiang@cloud.ionos.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-29blk-mq: drain I/O when all CPUs in a hctx are offlineMing Lei
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup up queue mapping. Thomas mentioned the following point[1]: "That was the constraint of managed interrupts from the very beginning: The driver/subsystem has to quiesce the interrupt line and the associated queue _before_ it gets shutdown in CPU unplug and not fiddle with it until it's restarted by the core when the CPU is plugged in again." However, current blk-mq implementation doesn't quiesce hw queue before the last CPU in the hctx is shutdown. Even worse, CPUHP_BLK_MQ_DEAD is a cpuhp state handled after the CPU is down, so there isn't any chance to quiesce the hctx before shutting down the CPU. Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs where the last CPU goes away, and wait for completion of in-flight requests. This guarantees that there is no inflight I/O before shutting down the managed IRQ. Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need to wait for completion of in-flight requests from these drivers to avoid a potential dead-lock. It is safe to do this for stacking drivers as those do not use interrupts at all and their I/O completions are triggered by underlying devices I/O completion. [1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [hch: different retry mechanism, merged two patches, minor cleanups] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27dm: use bio_{start,end}_io_acctChristoph Hellwig
Switch dm to use the nicer bio accounting helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: use bio_{start,end}_io_acctChristoph Hellwig
Switch bcache to use the nicer bio accounting helpers, and call the routines where we also sample the start time to give coherent accounting results. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: configure the asynchronous registertion to be experimentalColy Li
In order to avoid the experimental async registration interface to be treated as new kernel ABI for common users, this patch makes it as an experimental kernel configure BCACHE_ASYNC_REGISTRAION. This interface is for extreme large cached data situation, to make sure the bcache device can always created without the udev timeout issue. For normal users the async or sync registration does not make difference. In future when we decide to use the asynchronous registration as default behavior, this experimental interface may be removed. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: asynchronous devices registrationColy Li
When there is a lot of data cached on cache device, the bcach internal btree can take a very long to validate during the backing device and cache device registration. In my test, it may takes 55+ minutes to check all the internal btree nodes. The problem is that the registration is invoked by udev rules and the udevd has 180 seconds timeout by default. If the btree node checking time is longer than udevd timeout, the registering process will be killed by udevd with SIGKILL. If the registering process has pending sigal, creating kthread for bcache will fail and the device registration will fail. The result is, for bcache device which cached a lot of data on cache device, the bcache device node like /dev/bcache<N> won't create always due to the very long btree checking time. A solution to avoid the udevd 180 seconds timeout is to register devices in an asynchronous way. Which is, after writing cache or backing device path into /sys/fs/bcache/register_async, the kernel code will create a kworker and move all the btree node checking (for cache device) or dirty data counting (for cached device) in the kwork context. Then the kworder is scheduled on system_wq and the registration code just returned to user space udev rule task. By this asynchronous way, the udev task for bcache rule will complete in seconds, no matter how long time spent in the kworker context, it won't be killed by udevd for a timeout. After all the checking and counting are done asynchronously in the kworker, the bcache device will eventually be created successfully. This patch does the above chagne and add a register sysfs file /sys/fs/bcache/register_async. Writing the registering device path into this sysfs file will do the asynchronous registration. The register_async interface is for very rare condition and won't be used for common users. In future I plan to make the asynchronous registration as default behavior, which depends on feedback for this patch. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: fix refcount underflow in bcache_device_free()Coly Li
The problematic code piece in bcache_device_free() is, 785 static void bcache_device_free(struct bcache_device *d) 786 { 787 struct gendisk *disk = d->disk; [snipped] 799 if (disk) { 800 if (disk->flags & GENHD_FL_UP) 801 del_gendisk(disk); 802 803 if (disk->queue) 804 blk_cleanup_queue(disk->queue); 805 806 ida_simple_remove(&bcache_device_idx, 807 first_minor_to_idx(disk->first_minor)); 808 put_disk(disk); 809 } [snipped] 816 } At line 808, put_disk(disk) may encounter kobject refcount of 'disk' being underflow. Here is how to reproduce the issue, - Attche the backing device to a cache device and do random write to make the cache being dirty. - Stop the bcache device while the cache device has dirty data of the backing device. - Only register the backing device back, NOT register cache device. - The bcache device node /dev/bcache0 won't show up, because backing device waits for the cache device shows up for the missing dirty data. - Now echo 1 into /sys/fs/bcache/pendings_cleanup, to stop the pending backing device. - After the pending backing device stopped, use 'dmesg' to check kernel message, a use-after-free warning from KASA reported the refcount of kobject linked to the 'disk' is underflow. The dropping refcount at line 808 in the above code piece is added by add_disk(d->disk) in bch_cached_dev_run(). But in the above condition the cache device is not registered, bch_cached_dev_run() has no chance to be called and the refcount is not added. The put_disk() for a non- added refcount of gendisk kobject triggers a underflow warning. This patch checks whether GENHD_FL_UP is set in disk->flags, if it is not set then the bcache device was not added, don't call put_disk() and the the underflow issue can be avoided. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: Convert pr_<level> uses to a more typical styleJoe Perches
Remove the trailing newline from the define of pr_fmt and add newlines to the uses. Miscellanea: o Convert bch_bkey_dump from multiple uses of pr_err to pr_cont as the earlier conversion was inappropriate done causing multiple lines to be emitted where only a single output line was desired o Use vsprintf extension %pV in bch_cache_set_error to avoid multiple line output where only a single line output was desired o Coalesce formats Fixes: 6ae63e3501c4 ("bcache: replace printk() by pr_*() routines") Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: remove redundant variables i and nColin Ian King
Variables i and n are being assigned but are never used. They are redundant and can be removed. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Coly Li <colyli@suse.de> Addresses-Coverity: ("Unused value") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22dm zoned: remove leftover hunk for switching to sequential zonesHannes Reinecke
Remove a leftover hunk to switch from random zones to sequential zones when selecting a reclaim zone; the logic has moved into the caller and this hunk is now pointless. Fixes: 34f5affd04c4 ("dm zoned: separate random and cache zones") Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-22block: remove the error_sector argument to blkdev_issue_flushChristoph Hellwig
The argument isn't used by any caller, and drivers don't fill out bi_sector for flush requests either. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-20dm zoned: terminate reclaim on congestionHannes Reinecke
When dmz_get_chunk_mapping() selects a zone which is under reclaim we should terminate the reclaim copy process. Since we're changing the zone itself, reclaim needs to run afterwards again anyway. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: start reclaim with sequential zonesHannes Reinecke
Sequential zones perform better for reclaim, so start off using them and only use random zones as a fallback when cache zones are present. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: reclaim random zones when idleHannes Reinecke
When the system is idle we should be starting reclaiming random zones, too. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: separate random and cache zonesHannes Reinecke
Instead of lumping emulated zones together with random zones we should be handling them as separate 'cache' zones. This improves code readability and allows an easier implementation of different cache policies. Also add additional allocation flags, to separate the type (cache, random, or sequential) from the purpose (eg reclaim). Also switch the allocation policy to not use random zones as buffer zones if cache zones are present. This avoids a performance drop when all cache zones are used. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: return NULL if dmz_get_zone_for_reclaim() fails to find a zoneHannes Reinecke
The only case where dmz_get_zone_for_reclaim() cannot return a zone is if the respective lists are empty. So we should just return a simple NULL value here as we really don't have an error code which would make sense. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: Avoid 64-bit division error in dmz_fixup_devicesNathan Chancellor
When building arm32 allyesconfig: ld.lld: error: undefined symbol: __aeabi_uldivmod >>> referenced by dm-zoned-target.c >>> md/dm-zoned-target.o:(dmz_ctr) in archive drivers/built-in.a dmz_fixup_devices uses DIV_ROUND_UP with variables of type sector_t. As such, it should be using DIV_ROUND_UP_SECTOR_T, which handles this automatically. Fixes: 70978208ec91 ("dm zoned: metadata version 2") Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm: use DMDEBUG macros now that they use pr_debug variantsMike Snitzer
Now that DMDEBUG uses pr_debug and DMDEBUG_LIMIT uses pr_debug_ratelimited cleanup DM's 2 direct pr_debug callers to use them to get the benefit of consistent DM_FMT formatting of debugging messages. While doing so, dm-mpath.c:dm_report_EIO() was switched over to using DMDEBUG_LIMIT due to the potential for error handling floods in the IO completion path. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: remove spurious newlines from debugging messagesHannes Reinecke
DMDEBUG will already add a newline to the logging messages, so we shouldn't be adding it to the message itself. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm: replace zero-length array with flexible-arrayGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: metadata version 2Hannes Reinecke
Implement handling for metadata version 2. The new metadata adds a label and UUID for the device mapper device, and additional UUID for the underlying block devices. It also allows for an additional regular drive to be used for emulating random access zones. The emulated zones will be placed logically in front of the zones from the zoned block device, causing the superblocks and metadata to be stored on that device. The first zone of the original zoned device will be used to hold another, tertiary copy of the metadata; this copy carries a generation number of 0 and is never updated; it's just used for identification. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: ignore metadata zone in dmz_alloc_zone()Hannes Reinecke
When looking up zones in dmz_alloc_zone() we need to ignore metadata zones so as not to accidentally overwrite metadata. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>