From 5fdee2127faa77c9c91862ad5e001dfab7013e92 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 5 Oct 2017 21:22:52 +0200 Subject: block: remove QUEUE_FLAG_STACKABLE We already have a queue_is_rq_based helper to check if a request_queue is request based, so we can remove the flag for it. Acked-by: Mike Snitzer Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 02fa42d24b52..9fb71fc7d0e8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -609,7 +609,6 @@ struct request_queue { #define QUEUE_FLAG_NOMERGES 5 /* disable merge attempts */ #define QUEUE_FLAG_SAME_COMP 6 /* complete on same CPU-group */ #define QUEUE_FLAG_FAIL_IO 7 /* fake timeout */ -#define QUEUE_FLAG_STACKABLE 8 /* supports request stacking */ #define QUEUE_FLAG_NONROT 9 /* non-rotational device (SSD) */ #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ #define QUEUE_FLAG_IO_STAT 10 /* do IO stats */ @@ -633,12 +632,10 @@ struct request_queue { #define QUEUE_FLAG_QUIESCED 28 /* queue has been quiesced */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ - (1 << QUEUE_FLAG_STACKABLE) | \ (1 << QUEUE_FLAG_SAME_COMP) | \ (1 << QUEUE_FLAG_ADD_RANDOM)) #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ - (1 << QUEUE_FLAG_STACKABLE) | \ (1 << QUEUE_FLAG_SAME_COMP) | \ (1 << QUEUE_FLAG_POLL)) @@ -722,8 +719,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) -#define blk_queue_stackable(q) \ - test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) #define blk_queue_secure_erase(q) \ (test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags)) -- cgit v1.2.3 From 7f66721a7d5bf6251f9c49aada9200c61ddcecc5 Mon Sep 17 00:00:00 2001 From: Rakesh Pandit Date: Thu, 12 Oct 2017 19:58:10 +0300 Subject: fs/block_dev: remove vfs_msg() interface Replaced by pr_err usage in commit ef51042472f5 ("block, dax: move "select DAX" from BLOCK to FS_DAX") Signed-off-by: Rakesh Pandit Acked-by: Ross Zwisler Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 9fb71fc7d0e8..72637028f3c9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -917,17 +917,6 @@ static inline void rq_flush_dcache_pages(struct request *rq) } #endif -#ifdef CONFIG_PRINTK -#define vfs_msg(sb, level, fmt, ...) \ - __vfs_msg(sb, level, fmt, ##__VA_ARGS__) -#else -#define vfs_msg(sb, level, fmt, ...) \ -do { \ - no_printk(fmt, ##__VA_ARGS__); \ - __vfs_msg(sb, "", " "); \ -} while (0) -#endif - extern int blk_register_queue(struct gendisk *disk); extern void blk_unregister_queue(struct gendisk *disk); extern blk_qc_t generic_make_request(struct bio *bio); -- cgit v1.2.3 From f421e1d9ade4e1b88183e54425cf50e390d16a7f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 2 Nov 2017 21:29:50 +0300 Subject: block: provide a direct_make_request helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This helper allows reinserting a bio into a new queue without much overhead, but requires all queue limits to be the same for the upper and lower queues, and it does not provide any recursion preventions. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Javier González Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 72637028f3c9..eda3d25c0f68 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -920,6 +920,7 @@ static inline void rq_flush_dcache_pages(struct request *rq) extern int blk_register_queue(struct gendisk *disk); extern void blk_unregister_queue(struct gendisk *disk); extern blk_qc_t generic_make_request(struct bio *bio); +extern blk_qc_t direct_make_request(struct bio *bio); extern void blk_rq_init(struct request_queue *q, struct request *rq); extern void blk_init_request_from_bio(struct request *req, struct bio *bio); extern void blk_put_request(struct request *); -- cgit v1.2.3 From ef71de8b15d891b27b8c983a9a8972b11cb4576a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 2 Nov 2017 21:29:51 +0300 Subject: block: add a blk_steal_bios helper This helpers allows to bounce steal the uncompleted bios from a request so that they can be reissued on another path. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index eda3d25c0f68..fddda6a1f9b5 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1094,6 +1094,8 @@ extern struct request *blk_peek_request(struct request_queue *q); extern void blk_start_request(struct request *rq); extern struct request *blk_fetch_request(struct request_queue *q); +void blk_steal_bios(struct bio_list *list, struct request *rq); + /* * Request completion related functions. * -- cgit v1.2.3 From ea435e1b9392a33deceaea2a16ebaa3397bead93 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 2 Nov 2017 21:29:54 +0300 Subject: block: add a poll_fn callback to struct request_queue That we we can also poll non blk-mq queues. Mostly needed for the NVMe multipath code, but could also be useful elsewhere. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index fddda6a1f9b5..225617dd0a3f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -266,6 +266,7 @@ struct blk_queue_ctx; typedef void (request_fn_proc) (struct request_queue *q); typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio); +typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t); typedef int (prep_rq_fn) (struct request_queue *, struct request *); typedef void (unprep_rq_fn) (struct request_queue *, struct request *); @@ -408,6 +409,7 @@ struct request_queue { request_fn_proc *request_fn; make_request_fn *make_request_fn; + poll_q_fn *poll_fn; prep_rq_fn *prep_rq_fn; unprep_rq_fn *unprep_rq_fn; softirq_done_fn *softirq_done_fn; @@ -975,7 +977,7 @@ extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, int blk_status_to_errno(blk_status_t status); blk_status_t errno_to_blk_status(int errno); -bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie); +bool blk_poll(struct request_queue *q, blk_qc_t cookie); static inline struct request_queue *bdev_get_queue(struct block_device *bdev) { -- cgit v1.2.3 From f00c4d80ffdac9e3a64947ebd57489f3232d5a74 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 5 Nov 2017 10:36:31 +0300 Subject: block: pass full fmode_t to blk_verify_command Use the obvious calling convention. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 225617dd0a3f..1437ef4d8037 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1360,7 +1360,7 @@ static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, gfp_mask, 0); } -extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); +extern int blk_verify_command(unsigned char *cmd, fmode_t mode); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, -- cgit v1.2.3 From 6a15674d1e90917f1723a814e2e8c949000440f7 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 9 Nov 2017 10:49:54 -0800 Subject: block: Introduce blk_get_request_flags() A side effect of this patch is that the GFP mask that is passed to several allocation functions in the legacy block layer is changed from GFP_KERNEL into __GFP_DIRECT_RECLAIM. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Martin Steigerwald Tested-by: Oleksandr Natalenko Cc: Christoph Hellwig Cc: Ming Lei Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1437ef4d8037..1af5ddd0f631 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -927,6 +927,9 @@ extern void blk_rq_init(struct request_queue *q, struct request *rq); extern void blk_init_request_from_bio(struct request *req, struct bio *bio); extern void blk_put_request(struct request *); extern void __blk_put_request(struct request_queue *, struct request *); +extern struct request *blk_get_request_flags(struct request_queue *, + unsigned int op, + unsigned int flags); extern struct request *blk_get_request(struct request_queue *, unsigned int op, gfp_t gfp_mask); extern void blk_requeue_request(struct request_queue *, struct request *); -- cgit v1.2.3 From c9254f2ddb19387ea9714a57ea48463c20333b92 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 9 Nov 2017 10:49:57 -0800 Subject: block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag This flag will be used in the next patch to let the block layer core know whether or not a SCSI request queue has been quiesced. A quiesced SCSI queue namely only processes RQF_PREEMPT requests. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Martin Steigerwald Tested-by: Oleksandr Natalenko Cc: Ming Lei Cc: Christoph Hellwig Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1af5ddd0f631..2147e2381a22 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -632,6 +632,7 @@ struct request_queue { #define QUEUE_FLAG_REGISTERED 26 /* queue has been registered to a disk */ #define QUEUE_FLAG_SCSI_PASSTHROUGH 27 /* queue supports SCSI commands */ #define QUEUE_FLAG_QUIESCED 28 /* queue has been quiesced */ +#define QUEUE_FLAG_PREEMPT_ONLY 29 /* only process REQ_PREEMPT requests */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_SAME_COMP) | \ @@ -732,6 +733,11 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ REQ_FAILFAST_DRIVER)) #define blk_queue_quiesced(q) test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags) +#define blk_queue_preempt_only(q) \ + test_bit(QUEUE_FLAG_PREEMPT_ONLY, &(q)->queue_flags) + +extern int blk_set_preempt_only(struct request_queue *q); +extern void blk_clear_preempt_only(struct request_queue *q); static inline bool blk_account_rq(struct request *rq) { -- cgit v1.2.3 From 3a0a529971ec4e2d933e9c7798db101dfb6b1aec Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 9 Nov 2017 10:49:58 -0800 Subject: block, scsi: Make SCSI quiesce and resume work reliably The contexts from which a SCSI device can be quiesced or resumed are: * Writing into /sys/class/scsi_device/*/device/state. * SCSI parallel (SPI) domain validation. * The SCSI device power management methods. See also scsi_bus_pm_ops. It is essential during suspend and resume that neither the filesystem state nor the filesystem metadata in RAM changes. This is why while the hibernation image is being written or restored that SCSI devices are quiesced. The SCSI core quiesces devices through scsi_device_quiesce() and scsi_device_resume(). In the SDEV_QUIESCE state execution of non-preempt requests is deferred. This is realized by returning BLKPREP_DEFER from inside scsi_prep_state_check() for quiesced SCSI devices. Avoid that a full queue prevents power management requests to be submitted by deferring allocation of non-preempt requests for devices in the quiesced state. This patch has been tested by running the following commands and by verifying that after each resume the fio job was still running: for ((i=0; i<10; i++)); do ( cd /sys/block/md0/md && while true; do [ "$( sync_action sleep 1 done ) & pids=($!) for d in /sys/class/block/sd*[a-z]; do bdev=${d#/sys/class/block/} hcil=$(readlink "$d/device") hcil=${hcil#../../../} echo 4 > "$d/queue/nr_requests" echo 1 > "/sys/class/scsi_device/$hcil/device/queue_depth" fio --name="$bdev" --filename="/dev/$bdev" --buffered=0 --bs=512 \ --rw=randread --ioengine=libaio --numjobs=4 --iodepth=16 \ --iodepth_batch=1 --thread --loops=$((2**31)) & pids+=($!) done sleep 1 echo "$(date) Hibernating ..." >>hibernate-test-log.txt systemctl hibernate sleep 10 kill "${pids[@]}" echo idle > /sys/block/md0/md/sync_action wait echo "$(date) Done." >>hibernate-test-log.txt done Reported-by: Oleksandr Natalenko References: "I/O hangs after resuming from suspend-to-ram" (https://marc.info/?l=linux-block&m=150340235201348). Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Martin Steigerwald Tested-by: Oleksandr Natalenko Cc: Martin K. Petersen Cc: Ming Lei Cc: Christoph Hellwig Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2147e2381a22..402c9d536ae1 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -959,7 +959,7 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, struct scsi_ioctl_command __user *); -extern int blk_queue_enter(struct request_queue *q, bool nowait); +extern int blk_queue_enter(struct request_queue *q, unsigned int flags); extern void blk_queue_exit(struct request_queue *q); extern void blk_start_queue(struct request_queue *q); extern void blk_start_queue_async(struct request_queue *q); -- cgit v1.2.3 From 9a95e4ef709533efac4aafcb8bddf73f96db50ed Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 9 Nov 2017 10:49:59 -0800 Subject: block, nvme: Introduce blk_mq_req_flags_t Several block layer and NVMe core functions accept a combination of BLK_MQ_REQ_* flags through the 'flags' argument but there is no verification at compile time whether the right type of block layer flags is passed. Make it possible for sparse to verify this. This patch does not change any functionality. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Oleksandr Natalenko Cc: linux-nvme@lists.infradead.org Cc: Christoph Hellwig Cc: Johannes Thumshirn Cc: Ming Lei Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 402c9d536ae1..e80ea1d31343 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -935,7 +935,7 @@ extern void blk_put_request(struct request *); extern void __blk_put_request(struct request_queue *, struct request *); extern struct request *blk_get_request_flags(struct request_queue *, unsigned int op, - unsigned int flags); + blk_mq_req_flags_t flags); extern struct request *blk_get_request(struct request_queue *, unsigned int op, gfp_t gfp_mask); extern void blk_requeue_request(struct request_queue *, struct request *); @@ -959,7 +959,7 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, struct scsi_ioctl_command __user *); -extern int blk_queue_enter(struct request_queue *q, unsigned int flags); +extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags); extern void blk_queue_exit(struct request_queue *q); extern void blk_start_queue(struct request_queue *q); extern void blk_start_queue_async(struct request_queue *q); -- cgit v1.2.3 From 14cb0dc6479dc5ebc63b3a459a5d89a2f1b39fed Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 18 Dec 2017 15:40:43 +0800 Subject: block: don't let passthrough IO go into .make_request_fn() Commit a8821f3f3("block: Improvements to bounce-buffer handling") tries to make sure that the bio to .make_request_fn won't exceed BIO_MAX_PAGES, but ignores that passthrough I/O can use blk_queue_bounce() too. Especially, passthrough IO may not be sector-aligned, and the check of 'sectors < bio_sectors(*bio_orig)' inside __blk_queue_bounce() may become true even though the max bvec number doesn't exceed BIO_MAX_PAGES, then cause the bio splitted, and the original passthrough bio is submited to generic_make_request(). This patch fixes this issue by checking if the bio is passthrough IO, and use bio_kmalloc() to allocate the cloned passthrough bio. Cc: NeilBrown Fixes: a8821f3f3("block: Improvements to bounce-buffer handling") Tested-by: Michele Ballabio Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8089ca17db9a..abd06f540863 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -241,14 +241,24 @@ struct request { struct request *next_rq; }; +static inline bool blk_op_is_scsi(unsigned int op) +{ + return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT; +} + +static inline bool blk_op_is_private(unsigned int op) +{ + return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT; +} + static inline bool blk_rq_is_scsi(struct request *rq) { - return req_op(rq) == REQ_OP_SCSI_IN || req_op(rq) == REQ_OP_SCSI_OUT; + return blk_op_is_scsi(req_op(rq)); } static inline bool blk_rq_is_private(struct request *rq) { - return req_op(rq) == REQ_OP_DRV_IN || req_op(rq) == REQ_OP_DRV_OUT; + return blk_op_is_private(req_op(rq)); } static inline bool blk_rq_is_passthrough(struct request *rq) @@ -256,6 +266,13 @@ static inline bool blk_rq_is_passthrough(struct request *rq) return blk_rq_is_scsi(rq) || blk_rq_is_private(rq); } +static inline bool bio_is_passthrough(struct bio *bio) +{ + unsigned op = bio_op(bio); + + return blk_op_is_scsi(op) || blk_op_is_private(op); +} + static inline unsigned short req_get_ioprio(struct request *req) { return req->ioprio; -- cgit v1.2.3 From 0abc2a10389f0c9070f76ca906c7382788036b93 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 18 Dec 2017 15:40:44 +0800 Subject: block: fix blk_rq_append_bio Commit caa4b02476e3(blk-map: call blk_queue_bounce from blk_rq_append_bio) moves blk_queue_bounce() into blk_rq_append_bio(), but don't consider the fact that the bounced bio becomes invisible to caller since the parameter type is 'struct bio *'. Make it a pointer to a pointer to a bio, so the caller sees the right bio also after a bounce. Fixes: caa4b02476e3 ("blk-map: call blk_queue_bounce from blk_rq_append_bio") Cc: Christoph Hellwig Reported-by: Michele Ballabio (handling failure of blk_rq_append_bio(), only call bio_get() after blk_rq_append_bio() returns OK) Tested-by: Michele Ballabio Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index abd06f540863..100d0df38026 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -965,7 +965,7 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, extern void blk_rq_unprep_clone(struct request *rq); extern blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq); -extern int blk_rq_append_bio(struct request *rq, struct bio *bio); +extern int blk_rq_append_bio(struct request *rq, struct bio **bio); extern void blk_delay_queue(struct request_queue *, unsigned long); extern void blk_queue_split(struct request_queue *, struct bio **); extern void blk_recount_segments(struct request_queue *, struct bio *); -- cgit v1.2.3 From 4ccafe032005e9b96acbef2e389a4de5b1254add Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 20 Dec 2017 13:13:58 -0700 Subject: block: unalign call_single_data in struct request A previous change blindly added massive alignment to the call_single_data structure in struct request. This ballooned it in size from 296 to 320 bytes on my setup, for no valid reason at all. Use the unaligned struct __call_single_data variant instead. Fixes: 966a967116e69 ("smp: Avoid using two cache lines for struct call_single_data") Cc: stable@vger.kernel.org # v4.14 Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 100d0df38026..0ce8a372d506 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -135,7 +135,7 @@ typedef __u32 __bitwise req_flags_t; struct request { struct list_head queuelist; union { - call_single_data_t csd; + struct __call_single_data csd; u64 fifo_time; }; -- cgit v1.2.3 From 6cc77e9cb08041627fe1d32ac3a743249deb8167 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 21 Dec 2017 15:43:38 +0900 Subject: block: introduce zoned block devices zone write locking Components relying only on the request_queue structure for accessing block devices (e.g. I/O schedulers) have a limited knowledged of the device characteristics. In particular, the device capacity cannot be easily discovered, which for a zoned block device also result in the inability to easily know the number of zones of the device (the zone size is indicated by the chunk_sectors field of the queue limits). Introduce the nr_zones field to the request_queue structure to simplify access to this information. Also, add the bitmap seq_zone_bitmap which indicates which zones of the device are sequential zones (write preferred or write required) and the bitmap seq_zones_wlock which indicates if a zone is write locked, that is, if a write request targeting a zone was dispatched to the device. These fields are initialized by the low level block device driver (sd.c for ZBC/ZAC disks). They are not initialized by stacking drivers (device mappers) handling zoned block devices (e.g. dm-linear). Using this, I/O schedulers can introduce zone write locking to control request dispatching to a zoned block device and avoid write request reordering by limiting to at most a single write request per zone outside of the scheduler at any time. Based on previous patches from Damien Le Moal. Signed-off-by: Christoph Hellwig [Damien] * Fixed comments and identation in blkdev.h * Changed helper functions * Fixed this commit message Signed-off-by: Damien Le Moal Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 111 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8089ca17db9a..46e606f5b44b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -121,6 +121,8 @@ typedef __u32 __bitwise req_flags_t; /* Look at ->special_vec for the actual data payload instead of the bio chain. */ #define RQF_SPECIAL_PAYLOAD ((__force req_flags_t)(1 << 18)) +/* The per-zone write lock is held for this request */ +#define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \ @@ -546,6 +548,22 @@ struct request_queue { struct queue_limits limits; + /* + * Zoned block device information for request dispatch control. + * nr_zones is the total number of zones of the device. This is always + * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones + * bits which indicates if a zone is conventional (bit clear) or + * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones + * bits which indicates if a zone is write locked, that is, if a write + * request targeting the zone was dispatched. All three fields are + * initialized by the low level device driver (e.g. scsi/sd.c). + * Stacking drivers (device mappers) may or may not initialize + * these fields. + */ + unsigned int nr_zones; + unsigned long *seq_zones_bitmap; + unsigned long *seq_zones_wlock; + /* * sg stuff */ @@ -790,6 +808,27 @@ static inline unsigned int blk_queue_zone_sectors(struct request_queue *q) return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0; } +static inline unsigned int blk_queue_nr_zones(struct request_queue *q) +{ + return q->nr_zones; +} + +static inline unsigned int blk_queue_zone_no(struct request_queue *q, + sector_t sector) +{ + if (!blk_queue_is_zoned(q)) + return 0; + return sector >> ilog2(q->limits.chunk_sectors); +} + +static inline bool blk_queue_zone_is_seq(struct request_queue *q, + sector_t sector) +{ + if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap) + return false; + return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap); +} + static inline bool rq_is_sync(struct request *rq) { return op_is_sync(rq->cmd_flags); @@ -1029,6 +1068,16 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq) return blk_rq_cur_bytes(rq) >> 9; } +static inline unsigned int blk_rq_zone_no(struct request *rq) +{ + return blk_queue_zone_no(rq->q, blk_rq_pos(rq)); +} + +static inline unsigned int blk_rq_zone_is_seq(struct request *rq) +{ + return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq)); +} + /* * Some commands like WRITE SAME have a payload or data transfer size which * is different from the size of the request. Any driver that supports such @@ -1578,7 +1627,15 @@ static inline unsigned int bdev_zone_sectors(struct block_device *bdev) if (q) return blk_queue_zone_sectors(q); + return 0; +} +static inline unsigned int bdev_nr_zones(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + + if (q) + return blk_queue_nr_zones(q); return 0; } @@ -1954,6 +2011,60 @@ extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, extern int bdev_read_page(struct block_device *, sector_t, struct page *); extern int bdev_write_page(struct block_device *, sector_t, struct page *, struct writeback_control *); + +#ifdef CONFIG_BLK_DEV_ZONED +bool blk_req_needs_zone_write_lock(struct request *rq); +void __blk_req_zone_write_lock(struct request *rq); +void __blk_req_zone_write_unlock(struct request *rq); + +static inline void blk_req_zone_write_lock(struct request *rq) +{ + if (blk_req_needs_zone_write_lock(rq)) + __blk_req_zone_write_lock(rq); +} + +static inline void blk_req_zone_write_unlock(struct request *rq) +{ + if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED) + __blk_req_zone_write_unlock(rq); +} + +static inline bool blk_req_zone_is_write_locked(struct request *rq) +{ + return rq->q->seq_zones_wlock && + test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock); +} + +static inline bool blk_req_can_dispatch_to_zone(struct request *rq) +{ + if (!blk_req_needs_zone_write_lock(rq)) + return true; + return !blk_req_zone_is_write_locked(rq); +} +#else +static inline bool blk_req_needs_zone_write_lock(struct request *rq) +{ + return false; +} + +static inline void blk_req_zone_write_lock(struct request *rq) +{ +} + +static inline void blk_req_zone_write_unlock(struct request *rq) +{ +} +static inline bool blk_req_zone_is_write_locked(struct request *rq) +{ + return false; +} + +static inline bool blk_req_can_dispatch_to_zone(struct request *rq) +{ + return true; +} +#endif /* CONFIG_BLK_DEV_ZONED */ + #else /* CONFIG_BLOCK */ struct block_device; -- cgit v1.2.3 From 1d9bd5161ba32db5665a617edc8b0723880f543e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 9 Jan 2018 08:29:48 -0800 Subject: blk-mq: replace timeout synchronization with a RCU and generation based scheme Currently, blk-mq timeout path synchronizes against the usual issue/completion path using a complex scheme involving atomic bitflags, REQ_ATOM_*, memory barriers and subtle memory coherence rules. Unfortunately, it contains quite a few holes. There's a complex dancing around REQ_ATOM_STARTED and REQ_ATOM_COMPLETE between issue/completion and timeout paths; however, they don't have a synchronization point across request recycle instances and it isn't clear what the barriers add. blk_mq_check_expired() can easily read STARTED from N-2'th iteration, deadline from N-1'th, blk_mark_rq_complete() against Nth instance. In fact, it's pretty easy to make blk_mq_check_expired() terminate a later instance of a request. If we induce 5 sec delay before time_after_eq() test in blk_mq_check_expired(), shorten the timeout to 2s, and issue back-to-back large IOs, blk-mq starts timing out requests spuriously pretty quickly. Nothing actually timed out. It just made the call on a recycle instance of a request and then terminated a later instance long after the original instance finished. The scenario isn't theoretical either. This patch replaces the broken synchronization mechanism with a RCU and generation number based one. 1. Each request has a u64 generation + state value, which can be updated only by the request owner. Whenever a request becomes in-flight, the generation number gets bumped up too. This provides the basis for the timeout path to distinguish different recycle instances of the request. Also, marking a request in-flight and setting its deadline are protected with a seqcount so that the timeout path can fetch both values coherently. 2. The timeout path fetches the generation, state and deadline. If the verdict is timeout, it records the generation into a dedicated request abortion field and does RCU wait. 3. The completion path is also protected by RCU (from the previous patch) and checks whether the current generation number and state match the abortion field. If so, it skips completion. 4. The timeout path, after RCU wait, scans requests again and terminates the ones whose generation and state still match the ones requested for abortion. By now, the timeout path knows that either the generation number and state changed if it lost the race or the completion will yield to it and can safely timeout the request. While it's more lines of code, it's conceptually simpler, doesn't depend on direct use of subtle memory ordering or coherence, and hopefully doesn't terminate the wrong instance. While this change makes REQ_ATOM_COMPLETE synchronization unnecessary between issue/complete and timeout paths, REQ_ATOM_COMPLETE isn't removed yet as it's still used in other places. Future patches will move all state tracking to the new mechanism and remove all bitops in the hot paths. Note that this patch adds a comment explaining a race condition in BLK_EH_RESET_TIMER path. The race has always been there and this patch doesn't change it. It's just documenting the existing race. v2: - Fixed BLK_EH_RESET_TIMER handling as pointed out by Jianchao. - s/request->gstate_seqc/request->gstate_seq/ as suggested by Peter. - READ_ONCE() added in blk_mq_rq_update_state() as suggested by Peter. v3: - Fixed possible extended seqcount / u64_stats_sync read looping spotted by Peter. - MQ_RQ_IDLE was incorrectly being set in complete_request instead of free_request. Fixed. v4: - Rebased on top of hctx_lock() refactoring patch. - Added comment explaining the use of hctx_lock() in completion path. v5: - Added comments requested by Bart. - Note the addition of BLK_EH_RESET_TIMER race condition in the commit message. Signed-off-by: Tejun Heo Cc: "jianchao.wang" Cc: Peter Zijlstra Cc: Christoph Hellwig Cc: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 46e606f5b44b..ae563d01b29d 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -27,6 +27,8 @@ #include #include #include +#include +#include struct module; struct scsi_ioctl_command; @@ -230,6 +232,27 @@ struct request { unsigned short write_hint; + /* + * On blk-mq, the lower bits of ->gstate (generation number and + * state) carry the MQ_RQ_* state value and the upper bits the + * generation number which is monotonically incremented and used to + * distinguish the reuse instances. + * + * ->gstate_seq allows updates to ->gstate and other fields + * (currently ->deadline) during request start to be read + * atomically from the timeout path, so that it can operate on a + * coherent set of information. + */ + seqcount_t gstate_seq; + u64 gstate; + + /* + * ->aborted_gstate is used by the timeout to claim a specific + * recycle instance of this request. See blk_mq_timeout_work(). + */ + struct u64_stats_sync aborted_gstate_sync; + u64 aborted_gstate; + unsigned long deadline; struct list_head timeout_list; -- cgit v1.2.3 From 634f9e4631a88025d3b90c1884e9a1b6a13d01d2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 9 Jan 2018 08:29:51 -0800 Subject: blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq After the recent updates to use generation number and state based synchronization, blk-mq no longer depends on REQ_ATOM_COMPLETE except to avoid firing the same timeout multiple times. Remove all REQ_ATOM_COMPLETE usages and use a new rq_flags flag RQF_MQ_TIMEOUT_EXPIRED to avoid firing the same timeout multiple times. This removes atomic bitops from hot paths too. v2: Removed blk_clear_rq_complete() from blk_mq_rq_timed_out(). v3: Added RQF_MQ_TIMEOUT_EXPIRED flag. Signed-off-by: Tejun Heo Cc: "jianchao.wang" Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ae563d01b29d..007a7cf1f262 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -125,6 +125,8 @@ typedef __u32 __bitwise req_flags_t; #define RQF_SPECIAL_PAYLOAD ((__force req_flags_t)(1 << 18)) /* The per-zone write lock is held for this request */ #define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19)) +/* timeout is expired */ +#define RQF_MQ_TIMEOUT_EXPIRED ((__force req_flags_t)(1 << 20)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \ -- cgit v1.2.3 From 76a86f9d027b342b8759a4b2f9f7fe046e284220 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 10 Jan 2018 11:30:56 -0700 Subject: block: remove REQ_ATOM_POLL_SLEPT We don't need this to be an atomic flag, it can be a regular flag. We either end up on the same CPU for the polling, in which case the state is sane, or we did the sleep which would imply the needed barrier to ensure we see the right state. Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 007a7cf1f262..ba31674d8581 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -127,6 +127,8 @@ typedef __u32 __bitwise req_flags_t; #define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19)) /* timeout is expired */ #define RQF_MQ_TIMEOUT_EXPIRED ((__force req_flags_t)(1 << 20)) +/* already slept for hybrid poll */ +#define RQF_MQ_POLL_SLEPT ((__force req_flags_t)(1 << 21)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \ -- cgit v1.2.3 From 0a72e7f44964b9ada3e5c15820372e9cb119bf80 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 9 Jan 2018 14:23:42 -0700 Subject: block: add accessors for setting/querying request deadline We reduce the resolution of request expiry, but since we're already using jiffies for this where resolution depends on the kernel configuration and since the timeout resolution is coarse anyway, that should be fine. Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ba31674d8581..aa6698cf483c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -257,7 +257,9 @@ struct request { struct u64_stats_sync aborted_gstate_sync; u64 aborted_gstate; - unsigned long deadline; + /* access through blk_rq_set_deadline, blk_rq_deadline */ + unsigned long __deadline; + struct list_head timeout_list; /* -- cgit v1.2.3 From e14575b3d457f5806d79b85886ef94d9c29e3b2a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 10 Jan 2018 11:34:25 -0700 Subject: block: convert REQ_ATOM_COMPLETE to stealing rq->__deadline bit We only have one atomic flag left. Instead of using an entire unsigned long for that, steal the bottom bit of the deadline field that we already reserved. Remove ->atomic_flags, since it's now unused. Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index aa6698cf483c..d4b2f7bb18d6 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -156,8 +156,6 @@ struct request { int internal_tag; - unsigned long atomic_flags; - /* the following two fields are internal, NEVER access directly */ unsigned int __data_len; /* total data len */ int tag; -- cgit v1.2.3 From 7c3fb70f0341f9d924818e648906774921f4bcb3 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 10 Jan 2018 11:46:39 -0700 Subject: block: rearrange a few request fields for better cache layout Move completion related items (like the call single data) near the end of the struct, instead of mixing them in with the initial queueing related fields. Move queuelist below the bio structures. Then we have all queueing related bits in the first cache line. This yields a 1.5-2% increase in IOPS for a null_blk test, both for sync and for high thread count access. Sync test goes form 975K to 992K, 32-thread case from 20.8M to 21.2M IOPS. Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d4b2f7bb18d6..71a9371c8182 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -141,12 +141,6 @@ typedef __u32 __bitwise req_flags_t; * especially blk_mq_rq_ctx_init() to take care of the added fields. */ struct request { - struct list_head queuelist; - union { - call_single_data_t csd; - u64 fifo_time; - }; - struct request_queue *q; struct blk_mq_ctx *mq_ctx; @@ -164,6 +158,8 @@ struct request { struct bio *bio; struct bio *biotail; + struct list_head queuelist; + /* * The hash is used inside the scheduler, and killed once the * request reaches the dispatch list. The ipi_list is only used @@ -211,19 +207,16 @@ struct request { struct hd_struct *part; unsigned long start_time; struct blk_issue_stat issue_stat; -#ifdef CONFIG_BLK_CGROUP - struct request_list *rl; /* rl this rq is alloced from */ - unsigned long long start_time_ns; - unsigned long long io_start_time_ns; /* when passed to hardware */ -#endif /* Number of scatter-gather DMA addr+len pairs after * physical address coalescing is performed. */ unsigned short nr_phys_segments; + #if defined(CONFIG_BLK_DEV_INTEGRITY) unsigned short nr_integrity_segments; #endif + unsigned short write_hint; unsigned short ioprio; unsigned int timeout; @@ -232,8 +225,6 @@ struct request { unsigned int extra_len; /* length of alignment and padding */ - unsigned short write_hint; - /* * On blk-mq, the lower bits of ->gstate (generation number and * state) carry the MQ_RQ_* state value and the upper bits the @@ -260,6 +251,11 @@ struct request { struct list_head timeout_list; + union { + call_single_data_t csd; + u64 fifo_time; + }; + /* * completion callback. */ @@ -268,6 +264,12 @@ struct request { /* for bidi */ struct request *next_rq; + +#ifdef CONFIG_BLK_CGROUP + struct request_list *rl; /* rl this rq is alloced from */ + unsigned long long start_time_ns; + unsigned long long io_start_time_ns; /* when passed to hardware */ +#endif }; static inline bool blk_rq_is_scsi(struct request *rq) -- cgit v1.2.3 From f5ced52aaa5494c1feb9f80252cb2a2cde0dace8 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 19 Jan 2018 08:58:56 -0800 Subject: block: Remove kblockd_schedule_delayed_work{,_on}() The previous patch removed all users of these two functions. Hence also remove the functions themselves. Reviewed-by: Mike Snitzer Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 71a9371c8182..afc43fb63c16 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1800,8 +1800,6 @@ static inline bool req_gap_front_merge(struct request *req, struct bio *bio) int kblockd_schedule_work(struct work_struct *work); int kblockd_schedule_work_on(int cpu, struct work_struct *work); -int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); -int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); #ifdef CONFIG_BLK_CGROUP -- cgit v1.2.3 From 096392e0714d3a520366ba467e215edf7280acff Mon Sep 17 00:00:00 2001 From: Minwoo Im Date: Thu, 15 Feb 2018 23:53:17 +0900 Subject: block: fix a typo in comment of BLK_MQ_POLL_STATS_BKTS Update comment typo _consisitent_ to _consistent_ from following commit. commit 0206319fdfee ("blk-mq: Fix poll_stat for new size-based bucketing.") Cc: Jens Axboe Signed-off-by: Minwoo Im Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4f3df807cf8f..ed63f3b69c12 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -49,7 +49,7 @@ struct blk_stat_callback; #define BLKDEV_MIN_RQ 4 #define BLKDEV_MAX_RQ 128 /* Default maximum */ -/* Must be consisitent with blk_mq_poll_stats_bkt() */ +/* Must be consistent with blk_mq_poll_stats_bkt() */ #define BLK_MQ_POLL_STATS_BKTS 16 /* -- cgit v1.2.3