user/sven/linux.git/block, branch v5.4-rc4

blk-rq-qos: fix first node deletion of rq_qos_del()

2019-10-15T16:13:13Z

rq_qos_del() incorrectly assigns the node being deleted to the head if it was the first on the list in the !prev path. Fix it by iterating with ** instead. Signed-off-by: Tejun Heo Cc: Josef Bacik Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe

blkcg: Fix multiple bugs in blkcg_activate_policy()

2019-10-15T16:13:00Z

blkcg_activate_policy() has the following bugs. * cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") added @blkcg to ->pd_alloc_fn(); however, blkcg_activate_policy() ends up using pd's allocated for the root blkcg for all preallocations, so ->pd_init_fn() for non-root blkcgs can be passed in pd's which are allocated for the root blkcg. For blk-iocost, this means that ->pd_init_fn() can write beyond the end of the allocated object as it determines the length of the flex array at the end based on the blkcg's nesting level. * Each pd is initialized as they get allocated. If alloc fails, the policy will get freed with pd's initialized on it. * After the above partial failure, the partial pds are not freed. This patch fixes all the above issues by * Restructuring blkcg_activate_policy() so that alloc and init passes are separate. Init takes place only after all allocs succeeded and on failure all allocated pds are freed. * Unifying and fixing the cleanup of the remaining pd_prealloc. Signed-off-by: Tejun Heo Fixes: cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") Signed-off-by: Jens Axboe

block: Fix elv_support_iosched()

2019-10-14T19:54:09Z

A BIO based request queue does not have a tag_set, which prevent testing for the flag BLK_MQ_F_NO_SCHED indicating that the queue does not require an elevator. This leads to an incorrect initialization of a default elevator in some cases such as BIO based null_blk (queue_mode == BIO) with zoned mode enabled as the default elevator in this case is mq-deadline instead of "none". Fix this by testing for a NULL queue mq_ops field which indicates that the queue is BIO based and should not have an elevator. Reported-by: Shinichiro Kawasaki Reviewed-by: Bob Liu Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

blk-wbt: fix performance regression in wbt scale_up/scale_down

2019-10-06T15:26:41Z

scale_up wakes up waiters after scaling up. But after scaling max, it should not wake up more waiters as waiters will not have anything to do. This patch fixes this by making scale_up (and also scale_down) return when threshold is reached. This bug causes increased fdatasync latency when fdatasync and dd conv=sync are performed in parallel on 4.19 compared to 4.14. This bug was introduced during refactoring of blk-wbt code. Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org Cc: Josef Bacik Signed-off-by: Harshad Shirwadkar Signed-off-by: Jens Axboe

block: sed-opal: fix sparse warning: convert __be64 data

2019-10-03T20:21:32Z

sparse warns about incorrect type when using __be64 data. It is not being converted to CPU-endian but it should be. Fixes these sparse warnings: ../block/sed-opal.c:375:20: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:375:20: expected unsigned long long [usertype] align ../block/sed-opal.c:375:20: got restricted __be64 const [usertype] alignment_granularity ../block/sed-opal.c:376:25: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:376:25: expected unsigned long long [usertype] lowest_lba ../block/sed-opal.c:376:25: got restricted __be64 const [usertype] lowest_aligned_lba Fixes: 455a7b238cd6 ("block: Add Sed-opal library") Cc: Scott Bauer Cc: Rafael Antognolli Cc: linux-block@vger.kernel.org Reviewed-by: Jon Derrick Signed-off-by: Randy Dunlap Signed-off-by: Jens Axboe

block: sed-opal: fix sparse warning: obsolete array init.

2019-10-03T20:21:30Z

Fix sparse warning: (missing '=') ../block/sed-opal.c:133:17: warning: obsolete array initializer, use C99 syntax Fixes: ff91064ea37c ("block: sed-opal: check size of shadow mbr") Cc: linux-block@vger.kernel.org Cc: Jonas Rabenstein Cc: David Kozub Reviewed-by: Scott Bauer Reviewed-by: Revanth Rajashekar Signed-off-by: Randy Dunlap Signed-off-by: Jens Axboe

blk-mq: apply normal plugging for HDD

2019-09-27T17:40:21Z

Some HDD drive may expose multiple hardware queues, such as MegraRaid. Let's apply the normal plugging for such devices because sequential IO may benefit a lot from plug merging. Cc: Bart Van Assche Cc: Hannes Reinecke Cc: Dave Chinner Reviewed-by: Damien Le Moal Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

blk-mq: honor IO scheduler for multiqueue devices

2019-09-27T17:38:28Z

If a device is using multiple queues, the IO scheduler may be bypassed. This may hurt performance for some slow MQ devices, and it also breaks zoned devices which depend on mq-deadline for respecting the write order in one zone. Don't bypass io scheduler if we have one setup. This patch can double sequential write performance basically on MQ scsi_debug when mq-deadline is applied. Cc: Bart Van Assche Cc: Hannes Reinecke Cc: Dave Chinner Reviewed-by: Javier González Reviewed-by: Damien Le Moal Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: fix null pointer dereference in blk_mq_rq_timed_out()

2019-09-27T13:01:25Z

We got a null pointer deference BUG_ON in blk_mq_rq_timed_out() as following: [ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040 [ 108.827059] PGD 0 P4D 0 [ 108.827313] Oops: 0000 [#1] SMP PTI [ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431 [ 108.829503] Workqueue: kblockd blk_mq_timeout_work [ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330 [ 108.838191] Call Trace: [ 108.838406] bt_iter+0x74/0x80 [ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450 [ 108.839074] ? __switch_to_asm+0x34/0x70 [ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.840273] ? syscall_return_via_sysret+0xf/0x7f [ 108.840732] blk_mq_timeout_work+0x74/0x200 [ 108.841151] process_one_work+0x297/0x680 [ 108.841550] worker_thread+0x29c/0x6f0 [ 108.841926] ? rescuer_thread+0x580/0x580 [ 108.842344] kthread+0x16a/0x1a0 [ 108.842666] ? kthread_flush_work+0x170/0x170 [ 108.843100] ret_from_fork+0x35/0x40 The bug is caused by the race between timeout handle and completion for flush request. When timeout handle function blk_mq_rq_timed_out() try to read 'req->q->mq_ops', the 'req' have completed and reinitiated by next flush request, which would call blk_rq_init() to clear 'req' as 0. After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"), normal requests lifetime are protected by refcount. Until 'rq->ref' drop to zero, the request can really be free. Thus, these requests cannot been reused before timeout handle finish. However, flush request has defined .end_io and rq->end_io() is still called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq' can be reused by the next flush request handle, resulting in null pointer deference BUG ON. We fix this problem by covering flush request with 'rq->ref'. If the refcount is not zero, flush_end_io() return and wait the last holder recall it. To record the request status, we add a new entry 'rq_status', which will be used in flush_end_io(). Cc: Christoph Hellwig Cc: Keith Busch Cc: Bart Van Assche Cc: stable@vger.kernel.org # v4.18+ Reviewed-by: Ming Lei Reviewed-by: Bob Liu Signed-off-by: Yufen Yu ------- v2: - move rq_status from struct request to struct blk_flush_queue v3: - remove unnecessary '{}' pair. v4: - let spinlock to protect 'fq->rq_status' v5: - move rq_status after flush_running_idx member of struct blk_flush_queue Signed-off-by: Jens Axboe

rq-qos: get rid of redundant wbt_update_limits()

2019-09-27T07:13:10Z

We have updated limits after calling wbt_set_min_lat(). No need to update again. Reviewed-by: Bob Liu Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe