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2020-03-29block: return NULL in blk_alloc_queue() on errorChaitanya Kulkarni
This patch fixes follwoing warning: block/blk-core.c: In function ‘blk_alloc_queue’: block/blk-core.c:558:10: warning: returning ‘int’ from a function with return type ‘struct request_queue *’ makes pointer from integer without a cast [-Wint-conversion] return -EINVAL; Fixes: 3d745ea5b095a ("block: simplify queue allocation") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27block: simplify queue allocationChristoph Hellwig
Current make_request based drivers use either blk_alloc_queue_node or blk_alloc_queue to allocate a queue, and then set up the make_request_fn function pointer and a few parameters using the blk_queue_make_request helper. Simplify this by passing the make_request pointer to blk_alloc_queue, and while at it merge the _node variant into the main helper by always passing a node_id, and remove the superfluous gfp_mask parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block/diskstats: replace time_in_queue with sum of request timesKonstantin Khlebnikov
Column "time_in_queue" in diskstats is supposed to show total waiting time of all requests. I.e. value should be equal to the sum of times from other columns. But this is not true, because column "time_in_queue" is counted separately in jiffies rather than in nanoseconds as other times. This patch removes redundant counter for "time_in_queue" and shows total time of read, write, discard and flush requests. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block/diskstats: more accurate approximation of io_ticks for slow disksKonstantin Khlebnikov
Currently io_ticks is approximated by adding one at each start and end of requests if jiffies counter has changed. This works perfectly for requests shorter than a jiffy or if one of requests starts/ends at each jiffy. If disk executes just one request at a time and they are longer than two jiffies then only first and last jiffies will be accounted. Fix is simple: at the end of request add up into io_ticks jiffies passed since last update rather than just one jiffy. Example: common HDD executes random read 4k requests around 12ms. fio --name=test --filename=/dev/sdb --rw=randread --direct=1 --runtime=30 & iostat -x 10 sdb Note changes of iostat's "%util" 8,43% -> 99,99% before/after patch: Before: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0,00 0,00 82,60 0,00 330,40 0,00 8,00 0,96 12,09 12,09 0,00 1,02 8,43 After: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0,00 0,00 82,50 0,00 330,00 0,00 8,00 1,00 12,10 12,10 0,00 12,12 99,99 Now io_ticks does not loose time between start and end of requests, but for queue-depth > 1 some I/O time between adjacent starts might be lost. For load estimation "%util" is not as useful as average queue length, but it clearly shows how often disk queue is completely empty. Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: cleanup for _blk/blk_rq_prep_cloneGuoqing Jiang
Both cmd and sense had been moved to scsi_request, so remove the related comments to avoid confusion. And as Bart suggested, move _blk_rq_prep_clone into the only caller (blk_rq_prep_clone). Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: remove redundant setting of QUEUE_FLAG_DYINGGuoqing Jiang
Previously, blk_cleanup_queue has called blk_set_queue_dying to set the flag, no need to do it again. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: use bio_{wouldblock,io}_error in direct_make_requestGuoqing Jiang
Use the two functions to simplify code. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: fix comment for blk_cloned_rq_check_limitsGuoqing Jiang
Since the later description mentioned "checked against the new queue limits", so make the change to avoid confusion. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-02block: Remove used kblockd_schedule_work_on()Daniel Wagner
Commit ee63cfa7fc19 ("block: add kblockd_schedule_work_on()") introduced the helper in 2016. Remove it because since then no caller was added. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-17block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAITRoman Penyaev
Non-mq devs do not honor REQ_NOWAIT so give a chance to the caller to repeat request gracefully on -EAGAIN error. The problem is well reproduced using io_uring: mkfs.ext4 /dev/ram0 mount /dev/ram0 /mnt # Preallocate a file dd if=/dev/zero of=/mnt/file bs=1M count=1 # Start fio with io_uring and get -EIO fio --rw=write --ioengine=io_uring --size=1M --direct=1 --name=job --filename=/mnt/file Signed-off-by: Roman Penyaev <rpenyaev@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-13Merge tag 'for-linus-20191212' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - stable fix for the bi_size overflow. Not a corruption issue, but a case wher we could merge but disallowed (Andreas) - NVMe pull request via Keith, with various fixes. - MD pull request from Song. - Merge window regression fix for the rq passthrough stats (Logan) - Remove unused blkcg_drain_queue() function (Guoqing) * tag 'for-linus-20191212' of git://git.kernel.dk/linux-block: blk-cgroup: remove blkcg_drain_queue block: fix NULL pointer dereference in account statistics with IDE md: make sure desc_nr less than MD_SB_DISKS md: raid1: check rdev before reference in raid1_sync_request func raid5: need to set STRIPE_HANDLE for batch head block: fix "check bi_size overflow before merge" nvme/pci: Fix read queue count nvme/pci Limit write queue sizes to possible cpus nvme/pci: Fix write and poll queue types nvme/pci: Remove last_cq_head nvme: Namepace identification descriptor list is optional nvme-fc: fix double-free scenarios on hw queues nvme: else following return is not needed nvme: add error message on mismatching controller ids nvme_fc: add module to ops template to allow module references nvmet-loop: Avoid preallocating big SGL for data nvme-fc: Avoid preallocating big SGL for data nvme-rdma: Avoid preallocating big SGL for data
2019-12-12block: fix NULL pointer dereference in account statistics with IDELogan Gunthorpe
The IDE driver creates some passthru requests which never get submitted to the block layer in such a way that blk_account_io_start() gets called. However, the driver still calls __blk_mq_end_request() in ide_end_rq() which will call blk_account_io_completion() which tries to dereferences req->part which is never set. See ide_prep_sense() for an example of where these requests come from. To fix this, blk_account_io_completion() and blk_account_io_done() should do nothing if req->part is not set. The back trace of this bug is: BUG: kernel NULL pointer dereference, address: 000002ac #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page *pde = 00000000 Oops: 0002 [#1] CPU: 0 PID: 237 Comm: kworker/0:1H Not tainted 5.4.0-rc2-00011-g48d9b0d43105e #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Workqueue: kblockd drive_rq_insert_work EIP: blk_account_io_completion+0x7a/0xf0 Code: 89 54 24 08 31 d2 89 4c 24 04 31 c9 c7 04 24 02 00 00 00 c1 ee 09 e8 f5 21 a6 ff e8 70 5c a7 ff 8b 53 60 8d 04 bd 00 00 00 00 <01> b4 02 ac 02 00 00 8b 9a 88 02 00 00 85 db 74 11 85 d2 74 51 8b EAX: 00000000 EBX: f5b80000 ECX: 00000000 EDX: 00000000 ESI: 00000000 EDI: 00000000 EBP: f3031e70 ESP: f3031e54 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010046 CR0: 80050033 CR2: 000002ac CR3: 03c25000 CR4: 000406d0 Call Trace: <IRQ> blk_update_request+0x85/0x420 ide_end_rq+0x38/0xa0 ide_complete_rq+0x3d/0x70 cdrom_newpc_intr+0x258/0xba0 ide_intr+0x135/0x250 __handle_irq_event_percpu+0x3e/0x250 handle_irq_event_percpu+0x1f/0x50 handle_irq_event+0x32/0x60 handle_level_irq+0x6c/0x110 handle_irq+0x72/0xa0 </IRQ> do_IRQ+0x45/0xad common_interrupt+0x115/0x11c Fixes: 48d9b0d43105 ("block: account statistics for passthrough requests") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-09treewide: Use sizeof_field() macroPankaj Bharadiya
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
2019-11-12block: Remove partition support for zoned block devicesDamien Le Moal
No known partitioning tool supports zoned block devices, especially the host managed flavor with strong sequential write constraints. Furthermore, there are also no known user nor use cases for partitioned zoned block devices. This patch removes partition device creation for zoned block devices, which allows simplifying the processing of zone commands for zoned block devices. A warning is added if a partition table is found on the device. For report zones operations no zone sector information remapping is necessary anymore, simplifying the code. Of note is that remapping of zone reports for DM targets is still necessary as done by dm_remap_zone_report(). Similarly, remaping of a zone reset bio is not necessary anymore. Testing for the applicability of the zone reset all request also becomes simpler and only needs to check that the number of sectors of the requested zone range is equal to the disk capacity. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07block: add zone open, close and finish operationsAjay Joshi
Zoned block devices (ZBC and ZAC devices) allow an explicit control over the condition (state) of zones. The operations allowed are: * Open a zone: Transition to open condition to indicate that a zone will actively be written * Close a zone: Transition to closed condition to release the drive resources used for writing to a zone * Finish a zone: Transition an open or closed zone to the full condition to prevent write operations To enable this control for in-kernel zoned block device users, define the new request operations REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH as well as the generic function blkdev_zone_mgmt() for submitting these operations on a range of zones. This results in blkdev_reset_zones() removal and replacement with this new zone magement function. Users of blkdev_reset_zones() (f2fs and dm-zoned) are updated accordingly. Contains contributions from Matias Bjorling, Hans Holmberg, Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig. Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com> Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Reduce sysfs_lock locking inside blk_cleanup_queue()Bart Van Assche
Since blk_cleanup_queue() is called after blk_unregister_queue() and since that last function removes all sysfs attributes, serializing any code in blk_cleanup_queue() against sysfs callback methods nor against I/O scheduler changes is necessary. Hence remove the syfs_lock locking calls from the start of blk_cleanup_queue(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Remove "dying" checks from sysfs callbacksBart Van Assche
Block drivers must call del_gendisk() before blk_cleanup_queue(). del_gendisk() calls kobject_del() and kobject_del() waits until any ongoing sysfs callback functions have finished. In other words, the sysfs callback functions won't be called for a queue in the dying state. Hence remove the "dying" checks from the sysfs callback functions. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17block: centralize PI remapping logic to the block layerMax Gurtovoy
Currently t10_pi_prepare/t10_pi_complete functions are called during the NVMe and SCSi layers command preparetion/completion, but their actual place should be the block layer since T10-PI is a general data integrity feature that is used by block storage protocols. Introduce .prepare_fn and .complete_fn callbacks within the integrity profile that each type can implement according to its needs. Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Suggested-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Fixed to not call queue integrity functions if BLK_DEV_INTEGRITY isn't defined in the config. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-28block/rq_qos: add rq_qos_merge()Tejun Heo
Add a merge hook for rq_qos. This will be used by io.weight. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-27block: split .sysfs_lock into two locksMing Lei
The kernfs built-in lock of 'kn->count' is held in sysfs .show/.store path. Meantime, inside block's .show/.store callback, q->sysfs_lock is required. However, when mq & iosched kobjects are removed via blk_mq_unregister_dev() & elv_unregister_queue(), q->sysfs_lock is held too. This way causes AB-BA lock because the kernfs built-in lock of 'kn-count' is required inside kobject_del() too, see the lockdep warning[1]. On the other hand, it isn't necessary to acquire q->sysfs_lock for both blk_mq_unregister_dev() & elv_unregister_queue() because clearing REGISTERED flag prevents storing to 'queue/scheduler' from being happened. Also sysfs write(store) is exclusive, so no necessary to hold the lock for elv_unregister_queue() when it is called in switching elevator path. So split .sysfs_lock into two: one is still named as .sysfs_lock for covering sync .store, the other one is named as .sysfs_dir_lock for covering kobjects and related status change. sysfs itself can handle the race between add/remove kobjects and showing/storing attributes under kobjects. For switching scheduler via storing to 'queue/scheduler', we use the queue flag of QUEUE_FLAG_REGISTERED with .sysfs_lock for avoiding the race, then we can avoid to hold .sysfs_lock during removing/adding kobjects. [1] lockdep warning ====================================================== WARNING: possible circular locking dependency detected 5.3.0-rc3-00044-g73277fc75ea0 #1380 Not tainted ------------------------------------------------------ rmmod/777 is trying to acquire lock: 00000000ac50e981 (kn->count#202){++++}, at: kernfs_remove_by_name_ns+0x59/0x72 but task is already holding lock: 00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&q->sysfs_lock){+.+.}: __lock_acquire+0x95f/0xa2f lock_acquire+0x1b4/0x1e8 __mutex_lock+0x14a/0xa9b blk_mq_hw_sysfs_show+0x63/0xb6 sysfs_kf_seq_show+0x11f/0x196 seq_read+0x2cd/0x5f2 vfs_read+0xc7/0x18c ksys_read+0xc4/0x13e do_syscall_64+0xa7/0x295 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (kn->count#202){++++}: check_prev_add+0x5d2/0xc45 validate_chain+0xed3/0xf94 __lock_acquire+0x95f/0xa2f lock_acquire+0x1b4/0x1e8 __kernfs_remove+0x237/0x40b kernfs_remove_by_name_ns+0x59/0x72 remove_files+0x61/0x96 sysfs_remove_group+0x81/0xa4 sysfs_remove_groups+0x3b/0x44 kobject_del+0x44/0x94 blk_mq_unregister_dev+0x83/0xdd blk_unregister_queue+0xa0/0x10b del_gendisk+0x259/0x3fa null_del_dev+0x8b/0x1c3 [null_blk] null_exit+0x5c/0x95 [null_blk] __se_sys_delete_module+0x204/0x337 do_syscall_64+0xa7/0x295 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->sysfs_lock); lock(kn->count#202); lock(&q->sysfs_lock); lock(kn->count#202); *** DEADLOCK *** 2 locks held by rmmod/777: #0: 00000000e69bd9de (&lock){+.+.}, at: null_exit+0x2e/0x95 [null_blk] #1: 00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b stack backtrace: CPU: 0 PID: 777 Comm: rmmod Not tainted 5.3.0-rc3-00044-g73277fc75ea0 #1380 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS ?-20180724_192412-buildhw-07.phx4 Call Trace: dump_stack+0x9a/0xe6 check_noncircular+0x207/0x251 ? print_circular_bug+0x32a/0x32a ? find_usage_backwards+0x84/0xb0 check_prev_add+0x5d2/0xc45 validate_chain+0xed3/0xf94 ? check_prev_add+0xc45/0xc45 ? mark_lock+0x11b/0x804 ? check_usage_forwards+0x1ca/0x1ca __lock_acquire+0x95f/0xa2f lock_acquire+0x1b4/0x1e8 ? kernfs_remove_by_name_ns+0x59/0x72 __kernfs_remove+0x237/0x40b ? kernfs_remove_by_name_ns+0x59/0x72 ? kernfs_next_descendant_post+0x7d/0x7d ? strlen+0x10/0x23 ? strcmp+0x22/0x44 kernfs_remove_by_name_ns+0x59/0x72 remove_files+0x61/0x96 sysfs_remove_group+0x81/0xa4 sysfs_remove_groups+0x3b/0x44 kobject_del+0x44/0x94 blk_mq_unregister_dev+0x83/0xdd blk_unregister_queue+0xa0/0x10b del_gendisk+0x259/0x3fa ? disk_events_poll_msecs_store+0x12b/0x12b ? check_flags+0x1ea/0x204 ? mark_held_locks+0x1f/0x7a null_del_dev+0x8b/0x1c3 [null_blk] null_exit+0x5c/0x95 [null_blk] __se_sys_delete_module+0x204/0x337 ? free_module+0x39f/0x39f ? blkcg_maybe_throttle_current+0x8a/0x718 ? rwlock_bug+0x62/0x62 ? __blkcg_punt_bio_submit+0xd0/0xd0 ? trace_hardirqs_on_thunk+0x1a/0x20 ? mark_held_locks+0x1f/0x7a ? do_syscall_64+0x4c/0x295 do_syscall_64+0xa7/0x295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb696cdbe6b Code: 73 01 c3 48 8b 0d 1d 20 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 008 RSP: 002b:00007ffec9588788 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559e589137c0 RCX: 00007fb696cdbe6b RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559e58913828 RBP: 0000000000000000 R08: 00007ffec9587701 R09: 0000000000000000 R10: 00007fb696d4eae0 R11: 0000000000000206 R12: 00007ffec95889b0 R13: 00007ffec95896b3 R14: 0000559e58913260 R15: 0000559e589137c0 Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-19block: remove struct request_queue queue_headJunxiao Bi
The dispatch list is not used any more, as the legacy block IO stack has been removed. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-14block: annotate refault stalls from IO submissionJohannes Weiner
psi tracks the time tasks wait for refaulting pages to become uptodate, but it does not track the time spent submitting the IO. The submission part can be significant if backing storage is contended or when cgroup throttling (io.latency) is in effect - a lot of time is spent in submit_bio(). In that case, we underreport memory pressure. Annotate submit_bio() to account submission time as memory stall when the bio is reading userspace workingset pages. Tested-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-04blk-zoned: implement REQ_OP_ZONE_RESET_ALLChaitanya Kulkarni
This implements REQ_OP_ZONE_RESET_ALL as a special case of the block device zone reset operations where we just simply issue bio with the newly introduced req op. We issue this req op when the number of sectors is equal to the device's partition's number of sectors and device has no partitions. We also add support so that blk_op_str() can print the new reset-all zone operation. This patch also adds a generic make request check for newly introduced REQ_OP_ZONE_RESET_ALL req_opf. We simply return error when queue is zoned and reset-all flag is not set for REQ_OP_ZONE_RESET_ALL. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-04block: Fix a comment in blk_cleanup_queue()Bart Van Assche
Change a reference to the legacy block layer into a reference to blk-mq. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: James Smart <james.smart@broadcom.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10block: Disable write plugging for zoned block devicesDamien Le Moal
Simultaneously writing to a sequential zone of a zoned block device from multiple contexts requires mutual exclusion for BIO issuing to ensure that writes happen sequentially. However, even for a well behaved user correctly implementing such synchronization, BIO plugging may interfere and result in BIOs from the different contextx to be reordered if plugging is done outside of the mutual exclusion section, e.g. the plug was started by a function higher in the call chain than the function issuing BIOs. Context A Context B | blk_start_plug() | ... | seq_write_zone() | mutex_lock(zone) | bio-0->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-0) | submit_bio(bio-0) | bio-1->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-1) | submit_bio(bio-1) | mutex_unlock(zone) | return | -----------------------> | seq_write_zone() | mutex_lock(zone) | bio-2->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-2) | submit_bio(bio-2) | mutex_unlock(zone) | <------------------------- | | blk_finish_plug() In the above example, despite the mutex synchronization ensuring the correct BIO issuing order 0, 1, 2, context A BIOs 0 and 1 end up being issued after BIO 2 of context B, when the plug is released with blk_finish_plug(). While this problem can be addressed using the blk_flush_plug_list() function (in the above example, the call must be inserted before the zone mutex lock is released), a simple generic solution in the block layer avoid this additional code in all zoned block device user code. The simple generic solution implemented with this patch is to introduce the internal helper function blk_mq_plug() to access the current context plug on BIO submission. This helper returns the current plug only if the target device is not a zoned block device or if the BIO to be plugged is not a write operation. Otherwise, the caller context plug is ignored and NULL returned, resulting is all writes to zoned block device to never be plugged. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10blkcg: implement REQ_CGROUP_PUNTTejun Heo
When a shared kthread needs to issue a bio for a cgroup, doing so synchronously can lead to priority inversions as the kthread can be trapped waiting for that cgroup. This patch implements REQ_CGROUP_PUNT flag which makes submit_bio() punt the actual issuing to a dedicated per-blkcg work item to avoid such priority inversions. This will be used to fix priority inversions in btrfs compression and should be generally useful as we grow filesystem support for comprehensive IO control. Cc: Chris Mason <clm@fb.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10block: init flush rq ref count to 1Josef Bacik
We discovered a problem in newer kernels where a disconnect of a NBD device while the flush request was pending would result in a hang. This is because the blk mq timeout handler does if (!refcount_inc_not_zero(&rq->ref)) return true; to determine if it's ok to run the timeout handler for the request. Flush_rq's don't have a ref count set, so we'd skip running the timeout handler for this request and it would just sit there in limbo forever. Fix this by always setting the refcount of any request going through blk_init_rq() to 1. I tested this with a nbd-server that dropped flush requests to verify that it hung, and then tested with this patch to verify I got the timeout as expected and the error handling kicked in. Thanks, Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: update print_req_error()Chaitanya Kulkarni
Improve the print_req_error with additional request fields which are helpful for debugging. Use newly introduced blk_op_str() to print the REQ_OP_XXX in the string format. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: add centralize REQ_OP_XXX to string helperChaitanya Kulkarni
In order to centralize the REQ_OP_XXX to string conversion which can be used in the block layer and different places in the kernel like f2fs, this patch adds a new helper function along with an array similar to the one present in the blk-mq-debugfs.c. We keep this helper functionality centralize under blk-core.c instead of blk-mq-debugfs.c since blk-core.c is configured using CONFIG_BLOCK and it will not be dependent on blk-mq-debugfs.c which is configured using CONFIG_BLK_DEBUG_FS. Next patch adjusts the code in the blk-mq-debugfs.c with newly introduced helper. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: improve print_req_errorChristoph Hellwig
Print the calling function instead of print_req_error as a prefix, and print the operation and op_flags separately instead of the whole field. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: mark blk_rq_bio_prep as inlineChristoph Hellwig
This function just has a few trivial assignments, has two callers with one of them being in the fastpath. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: simplify blk_recalc_rq_segmentsChristoph Hellwig
Return the segement and let the callers assign them, which makes the code a littler more obvious. Also pass the request instead of q plus bio chain, allowing for the use of rq_for_each_bvec. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: remove the bi_phys_segments field in struct bioChristoph Hellwig
We only need the number of segments in the blk-mq submission path. Remove the field from struct bio, and return it from a variant of blk_queue_split instead of that it can passed as an argument to those functions that need the value. This also means we stop recounting segments except for cloning and partial segments. To keep the number of arguments in this how path down remove pointless struct request_queue arguments from any of the functions that had it and grew a nr_segs argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: remove blk_init_request_from_bioChristoph Hellwig
lightnvm should have never used this function, as it is sending passthrough requests, so switch it to blk_rq_append_bio like all the other passthrough request users. Inline blk_init_request_from_bio into the only remaining caller. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: initialize the write priority in blk_rq_bio_prepChristoph Hellwig
The priority field also makes sense for passthrough requests, so initialize it in blk_rq_bio_prep. Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20blk-core: Remove blk_end_request*() declarationsPavel Begunkov
Commit a1ce35fa49852db60fc6e268 ("block: remove dead elevator code") deleted blk_end_request() and friends, but some declaration are still left. Purge them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-06block: free sched's request pool in blk_cleanup_queueMing Lei
In theory, IO scheduler belongs to request queue, and the request pool of sched tags belongs to the request queue too. However, the current tags allocation interfaces are re-used for both driver tags and sched tags, and driver tags is definitely host wide, and doesn't belong to any request queue, same with its request pool. So we need tagset instance for freeing request of sched tags. Meantime, blk_mq_free_tag_set() often follows blk_cleanup_queue() in case of non-BLK_MQ_F_TAG_SHARED, this way requires that request pool of sched tags to be freed before calling blk_mq_free_tag_set(). Commit 47cdee29ef9d94e ("block: move blk_exit_queue into __blk_release_queue") moves blk_exit_queue into __blk_release_queue for simplying the fast path in generic_make_request(), then causes oops during freeing requests of sched tags in __blk_release_queue(). Fix the above issue by move freeing request pool of sched tags into blk_cleanup_queue(), this way is safe becasue queue has been frozen and no any in-queue requests at that time. Freeing sched tags has to be kept in queue's release handler becasue there might be un-completed dispatch activity which might refer to sched tags. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Christoph Hellwig <hch@lst.de> Fixes: 47cdee29ef9d94e485eb08f962c74943023a5271 ("block: move blk_exit_queue into __blk_release_queue") Tested-by: Yi Zhang <yi.zhang@redhat.com> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-31block: print offending values when cloned rq limits are exceededJohn Pittman
While troubleshooting issues where cloned request limits have been exceeded, it is often beneficial to know the actual values that have been breached. Print these values, assisting in ease of identification of root cause of the breach. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: John Pittman <jpittman@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-29block: don't protect generic_make_request_checks with blk_queue_enterMing Lei
Now a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller") has been reverted, and blkcg_exit_queue() won't be called in blk_cleanup_queue() any more. So don't need to protect generic_make_request_checks() with blk_queue_enter(), then the total mess can be cleaned. 37f9579f4c31 ("blk-mq: Avoid that submitting a bio concurrently with device removal triggers a crash") is reverted. Cc: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-29block: move blk_exit_queue into __blk_release_queueMing Lei
Commit 498f6650aec8 ("block: Fix a race between the cgroup code and request queue initialization") moves what blk_exit_queue does into blk_cleanup_queue() for fixing issue caused by changing back queue lock. However, after legacy request IO path is killed, driver queue lock won't be used at all, and there isn't story for changing back queue lock. Then the issue addressed by Commit 498f6650aec8 doesn't exist any more. So move move blk_exit_queue into __blk_release_queue. This patch basically reverts the following two commits: 498f6650aec8 block: Fix a race between the cgroup code and request queue initialization 24ecc3585348 block: Ensure that a request queue is dissociated from the cgroup controller Cc: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-23blk-mq: fix hang caused by freeze/unfreeze sequenceBob Liu
The following is a description of a hang in blk_mq_freeze_queue_wait(). The hang happens on attempt to freeze a queue while another task does queue unfreeze. The root cause is an incorrect sequence of percpu_ref_resurrect() and percpu_ref_kill() and as a result those two can be swapped: CPU#0 CPU#1 ---------------- ----------------- q1 = blk_mq_init_queue(shared_tags) q2 = blk_mq_init_queue(shared_tags): blk_mq_add_queue_tag_set(shared_tags): blk_mq_update_tag_set_depth(shared_tags): list_for_each_entry() blk_mq_freeze_queue(q1) > percpu_ref_kill() > blk_mq_freeze_queue_wait() blk_cleanup_queue(q1) blk_mq_freeze_queue(q1) > percpu_ref_kill() ^^^^^^ freeze_depth can't guarantee the order blk_mq_unfreeze_queue() > percpu_ref_resurrect() > blk_mq_freeze_queue_wait() ^^^^^^ Hang here!!!! This wrong sequence raises kernel warning: percpu_ref_kill_and_confirm called more than once on blk_queue_usage_counter_release! WARNING: CPU: 0 PID: 11854 at lib/percpu-refcount.c:336 percpu_ref_kill_and_confirm+0x99/0xb0 But the most unpleasant effect is a hang of a blk_mq_freeze_queue_wait(), which waits for a zero of a q_usage_counter, which never happens because percpu-ref was reinited (instead of being killed) and stays in PERCPU state forever. How to reproduce: - "insmod null_blk.ko shared_tags=1 nr_devices=0 queue_mode=2" - cpu0: python Script.py 0; taskset the corresponding process running on cpu0 - cpu1: python Script.py 1; taskset the corresponding process running on cpu1 Script.py: ------ #!/usr/bin/python3 import os import sys while True: on = "echo 1 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] off = "echo 0 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] os.system(on) os.system(off) ------ This bug was first reported and fixed by Roman, previous discussion: [1] Message id: 1443287365-4244-7-git-send-email-akinobu.mita@gmail.com [2] Message id: 1443563240-29306-6-git-send-email-tj@kernel.org [3] https://patchwork.kernel.org/patch/9268199/ Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-04block: don't drain in-progress dispatch in blk_cleanup_queue()Ming Lei
Now freeing hw queue resource is moved to hctx's release handler, we don't need to worry about the race between blk_cleanup_queue and run queue any more. So don't drain in-progress dispatch in blk_cleanup_queue(). This is basically revert of c2856ae2f315 ("blk-mq: quiesce queue before freeing queue"). Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: James Smart <james.smart@broadcom.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen <martin.petersen@oracle.com>, Cc: Christoph Hellwig <hch@lst.de>, Cc: James E . J . Bottomley <jejb@linux.vnet.ibm.com>, Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: James Smart <james.smart@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-04blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_releaseMing Lei
hctx is always released after requeue is freed. With holding queue's kobject refcount, it is safe for driver to run queue, so one run queue might be scheduled after blk_sync_queue() is done. So moving the cancel of hctx->run_work into blk_mq_hw_sysfs_release() for avoiding run released queue. Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: James Smart <james.smart@broadcom.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen <martin.petersen@oracle.com>, Cc: Christoph Hellwig <hch@lst.de>, Cc: James E . J . Bottomley <jejb@linux.vnet.ibm.com>, Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: James Smart <james.smart@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-04blk-mq: free hw queue's resource in hctx's release handlerMing Lei
Once blk_cleanup_queue() returns, tags shouldn't be used any more, because blk_mq_free_tag_set() may be called. Commit 45a9c9d909b2 ("blk-mq: Fix a use-after-free") fixes this issue exactly. However, that commit introduces another issue. Before 45a9c9d909b2, we are allowed to run queue during cleaning up queue if the queue's kobj refcount is held. After that commit, queue can't be run during queue cleaning up, otherwise oops can be triggered easily because some fields of hctx are freed by blk_mq_free_queue() in blk_cleanup_queue(). We have invented ways for addressing this kind of issue before, such as: 8dc765d438f1 ("SCSI: fix queue cleanup race before queue initialization is done") c2856ae2f315 ("blk-mq: quiesce queue before freeing queue") But still can't cover all cases, recently James reports another such kind of issue: https://marc.info/?l=linux-scsi&m=155389088124782&w=2 This issue can be quite hard to address by previous way, given scsi_run_queue() may run requeues for other LUNs. Fixes the above issue by freeing hctx's resources in its release handler, and this way is safe becasue tags isn't needed for freeing such hctx resource. This approach follows typical design pattern wrt. kobject's release handler. Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: James Smart <james.smart@broadcom.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen <martin.petersen@oracle.com>, Cc: Christoph Hellwig <hch@lst.de>, Cc: James E . J . Bottomley <jejb@linux.vnet.ibm.com>, Reported-by: James Smart <james.smart@broadcom.com> Fixes: 45a9c9d909b2 ("blk-mq: Fix a use-after-free") Cc: stable@vger.kernel.org Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: James Smart <james.smart@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-04blk-mq: move cancel of requeue_work into blk_mq_releaseMing Lei
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 <dongli.zhang@oracle.com> Cc: James Smart <james.smart@broadcom.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen <martin.petersen@oracle.com>, Cc: Christoph Hellwig <hch@lst.de>, Cc: James E . J . Bottomley <jejb@linux.vnet.ibm.com>, Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: James Smart <james.smart@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30block: add SPDX tags to block layer files missing licensing informationChristoph Hellwig
Various block layer files do not have any licensing information at all. Add SPDX tags for the default kernel GPLv2 license to those. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-05block: Revert v5.0 blk_mq_request_issue_directly() changesBart Van Assche
blk_mq_try_issue_directly() can return BLK_STS*_RESOURCE for requests that have been queued. If that happens when blk_mq_try_issue_directly() is called by the dm-mpath driver then dm-mpath will try to resubmit a request that is already queued and a kernel crash follows. Since it is nontrivial to fix blk_mq_request_issue_directly(), revert the blk_mq_request_issue_directly() changes that went into kernel v5.0. This patch reverts the following commits: * d6a51a97c0b2 ("blk-mq: replace and kill blk_mq_request_issue_directly") # v5.0. * 5b7a6f128aad ("blk-mq: issue directly with bypass 'false' in blk_mq_sched_insert_requests") # v5.0. * 7f556a44e61d ("blk-mq: refactor the code of issue request directly") # v5.0. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: James Smart <james.smart@broadcom.com> Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: <stable@vger.kernel.org> Reported-by: Laurence Oberman <loberman@redhat.com> Tested-by: Laurence Oberman <loberman@redhat.com> Fixes: 7f556a44e61d ("blk-mq: refactor the code of issue request directly") # v5.0. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-12mm: refactor readahead defines in mm.hNikolay Borisov
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This simplifies the expression in every filesystem. Also rename the macro to VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused VM_MIN_READAHEAD [akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen] Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: David Howells <dhowells@redhat.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: David Sterba <dsterba@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-30block: pass no-op callback to INIT_WORK().Tetsuo Handa
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 <penguin-kernel@I-love.SAKURA.ne.jp> Reported-and-tested-by: syzbot <syzbot+ba2a929dcf8e704c180e@syzkaller.appspotmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-27Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED"Jens Axboe
We can't touch a bio after ->make_request_fn(), for all we know it could already have been completed by the time this function returns. This reverts commit 698cef173983b086977e633e46476e0f925ca01e. Reported-by: syzbot+4df6ca820108fd248943@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>