diff options
Diffstat (limited to 'include/linux/blk-mq.h')
| -rw-r--r-- | include/linux/blk-mq.h | 1176 |
1 files changed, 1025 insertions, 151 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 0e030f5f76b6..cae9e857aea4 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -4,258 +4,750 @@ #include <linux/blkdev.h> #include <linux/sbitmap.h> +#include <linux/lockdep.h> +#include <linux/scatterlist.h> +#include <linux/prefetch.h> #include <linux/srcu.h> +#include <linux/rw_hint.h> +#include <linux/rwsem.h> struct blk_mq_tags; struct blk_flush_queue; +#define BLKDEV_MIN_RQ 4 +#define BLKDEV_DEFAULT_RQ 128 + +enum rq_end_io_ret { + RQ_END_IO_NONE, + RQ_END_IO_FREE, +}; + +typedef enum rq_end_io_ret (rq_end_io_fn)(struct request *, blk_status_t); + +/* + * request flags */ +typedef __u32 __bitwise req_flags_t; + +/* Keep rqf_name[] in sync with the definitions below */ +enum rqf_flags { + /* drive already may have started this one */ + __RQF_STARTED, + /* request for flush sequence */ + __RQF_FLUSH_SEQ, + /* merge of different types, fail separately */ + __RQF_MIXED_MERGE, + /* don't call prep for this one */ + __RQF_DONTPREP, + /* use hctx->sched_tags */ + __RQF_SCHED_TAGS, + /* use an I/O scheduler for this request */ + __RQF_USE_SCHED, + /* vaguely specified driver internal error. Ignored by block layer */ + __RQF_FAILED, + /* don't warn about errors */ + __RQF_QUIET, + /* account into disk and partition IO statistics */ + __RQF_IO_STAT, + /* runtime pm request */ + __RQF_PM, + /* on IO scheduler merge hash */ + __RQF_HASHED, + /* track IO completion time */ + __RQF_STATS, + /* Look at ->special_vec for the actual data payload instead of the + bio chain. */ + __RQF_SPECIAL_PAYLOAD, + /* request completion needs to be signaled to zone write plugging. */ + __RQF_ZONE_WRITE_PLUGGING, + /* ->timeout has been called, don't expire again */ + __RQF_TIMED_OUT, + __RQF_RESV, + __RQF_BITS +}; + +#define RQF_STARTED ((__force req_flags_t)(1 << __RQF_STARTED)) +#define RQF_FLUSH_SEQ ((__force req_flags_t)(1 << __RQF_FLUSH_SEQ)) +#define RQF_MIXED_MERGE ((__force req_flags_t)(1 << __RQF_MIXED_MERGE)) +#define RQF_DONTPREP ((__force req_flags_t)(1 << __RQF_DONTPREP)) +#define RQF_SCHED_TAGS ((__force req_flags_t)(1 << __RQF_SCHED_TAGS)) +#define RQF_USE_SCHED ((__force req_flags_t)(1 << __RQF_USE_SCHED)) +#define RQF_FAILED ((__force req_flags_t)(1 << __RQF_FAILED)) +#define RQF_QUIET ((__force req_flags_t)(1 << __RQF_QUIET)) +#define RQF_IO_STAT ((__force req_flags_t)(1 << __RQF_IO_STAT)) +#define RQF_PM ((__force req_flags_t)(1 << __RQF_PM)) +#define RQF_HASHED ((__force req_flags_t)(1 << __RQF_HASHED)) +#define RQF_STATS ((__force req_flags_t)(1 << __RQF_STATS)) +#define RQF_SPECIAL_PAYLOAD \ + ((__force req_flags_t)(1 << __RQF_SPECIAL_PAYLOAD)) +#define RQF_ZONE_WRITE_PLUGGING \ + ((__force req_flags_t)(1 << __RQF_ZONE_WRITE_PLUGGING)) +#define RQF_TIMED_OUT ((__force req_flags_t)(1 << __RQF_TIMED_OUT)) +#define RQF_RESV ((__force req_flags_t)(1 << __RQF_RESV)) + +/* flags that prevent us from merging requests: */ +#define RQF_NOMERGE_FLAGS \ + (RQF_STARTED | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD) + +enum mq_rq_state { + MQ_RQ_IDLE = 0, + MQ_RQ_IN_FLIGHT = 1, + MQ_RQ_COMPLETE = 2, +}; + +/* + * Try to put the fields that are referenced together in the same cacheline. + * + * If you modify this structure, make sure to update blk_rq_init() and + * especially blk_mq_rq_ctx_init() to take care of the added fields. + */ +struct request { + struct request_queue *q; + struct blk_mq_ctx *mq_ctx; + struct blk_mq_hw_ctx *mq_hctx; + + blk_opf_t cmd_flags; /* op and common flags */ + req_flags_t rq_flags; + + int tag; + int internal_tag; + + unsigned int timeout; + + /* the following two fields are internal, NEVER access directly */ + unsigned int __data_len; /* total data len */ + sector_t __sector; /* sector cursor */ + + struct bio *bio; + struct bio *biotail; + + union { + struct list_head queuelist; + struct request *rq_next; + }; + + struct block_device *part; +#ifdef CONFIG_BLK_RQ_ALLOC_TIME + /* Time that the first bio started allocating this request. */ + u64 alloc_time_ns; +#endif + /* Time that this request was allocated for this IO. */ + u64 start_time_ns; + /* Time that I/O was submitted to the device. */ + u64 io_start_time_ns; + +#ifdef CONFIG_BLK_WBT + unsigned short wbt_flags; +#endif + /* + * rq sectors used for blk stats. It has the same value + * with blk_rq_sectors(rq), except that it never be zeroed + * by completion. + */ + unsigned short stats_sectors; + + /* + * Number of scatter-gather DMA addr+len pairs after + * physical address coalescing is performed. + */ + unsigned short nr_phys_segments; + unsigned short nr_integrity_segments; + + /* + * The lowest set bit for address gaps between physical segments. This + * provides information necessary for dma optimization opprotunities, + * like for testing if the segments can be coalesced against the + * device's iommu granule. + */ + unsigned char phys_gap_bit; + +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + struct bio_crypt_ctx *crypt_ctx; + struct blk_crypto_keyslot *crypt_keyslot; +#endif + + enum mq_rq_state state; + atomic_t ref; + + unsigned long deadline; + + /* + * The hash is used inside the scheduler, and killed once the + * request reaches the dispatch list. The ipi_list is only used + * to queue the request for softirq completion, which is long + * after the request has been unhashed (and even removed from + * the dispatch list). + */ + union { + struct hlist_node hash; /* merge hash */ + struct llist_node ipi_list; + }; + + /* + * The rb_node is only used inside the io scheduler, requests + * are pruned when moved to the dispatch queue. special_vec must + * only be used if RQF_SPECIAL_PAYLOAD is set, and those cannot be + * insert into an IO scheduler. + */ + union { + struct rb_node rb_node; /* sort/lookup */ + struct bio_vec special_vec; + }; + + /* + * Three pointers are available for the IO schedulers, if they need + * more they have to dynamically allocate it. + */ + struct { + struct io_cq *icq; + void *priv[2]; + } elv; + + struct { + unsigned int seq; + rq_end_io_fn *saved_end_io; + } flush; + + u64 fifo_time; + + /* + * completion callback. + */ + rq_end_io_fn *end_io; + void *end_io_data; +}; + +/* + * Returns a mask with all bits starting at req->phys_gap_bit set to 1. + */ +static inline unsigned long req_phys_gap_mask(const struct request *req) +{ + return ~(((1 << req->phys_gap_bit) >> 1) - 1); +} + +static inline enum req_op req_op(const struct request *req) +{ + return req->cmd_flags & REQ_OP_MASK; +} + +static inline bool blk_rq_is_passthrough(struct request *rq) +{ + return blk_op_is_passthrough(rq->cmd_flags); +} + +static inline unsigned short req_get_ioprio(struct request *req) +{ + if (req->bio) + return req->bio->bi_ioprio; + return 0; +} + +#define rq_data_dir(rq) (op_is_write(req_op(rq)) ? WRITE : READ) + +#define rq_dma_dir(rq) \ + (op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE) + +static inline int rq_list_empty(const struct rq_list *rl) +{ + return rl->head == NULL; +} + +static inline void rq_list_init(struct rq_list *rl) +{ + rl->head = NULL; + rl->tail = NULL; +} + +static inline void rq_list_add_tail(struct rq_list *rl, struct request *rq) +{ + rq->rq_next = NULL; + if (rl->tail) + rl->tail->rq_next = rq; + else + rl->head = rq; + rl->tail = rq; +} + +static inline void rq_list_add_head(struct rq_list *rl, struct request *rq) +{ + rq->rq_next = rl->head; + rl->head = rq; + if (!rl->tail) + rl->tail = rq; +} + +static inline struct request *rq_list_pop(struct rq_list *rl) +{ + struct request *rq = rl->head; + + if (rq) { + rl->head = rl->head->rq_next; + if (!rl->head) + rl->tail = NULL; + rq->rq_next = NULL; + } + + return rq; +} + +static inline struct request *rq_list_peek(struct rq_list *rl) +{ + return rl->head; +} + +#define rq_list_for_each(rl, pos) \ + for (pos = rq_list_peek((rl)); (pos); pos = pos->rq_next) + +#define rq_list_for_each_safe(rl, pos, nxt) \ + for (pos = rq_list_peek((rl)), nxt = pos->rq_next; \ + pos; pos = nxt, nxt = pos ? pos->rq_next : NULL) + /** - * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware block device + * enum blk_eh_timer_return - How the timeout handler should proceed + * @BLK_EH_DONE: The block driver completed the command or will complete it at + * a later time. + * @BLK_EH_RESET_TIMER: Reset the request timer and continue waiting for the + * request to complete. + */ +enum blk_eh_timer_return { + BLK_EH_DONE, + BLK_EH_RESET_TIMER, +}; + +/** + * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware + * block device */ struct blk_mq_hw_ctx { struct { + /** @lock: Protects the dispatch list. */ spinlock_t lock; + /** + * @dispatch: Used for requests that are ready to be + * dispatched to the hardware but for some reason (e.g. lack of + * resources) could not be sent to the hardware. As soon as the + * driver can send new requests, requests at this list will + * be sent first for a fairer dispatch. + */ struct list_head dispatch; - unsigned long state; /* BLK_MQ_S_* flags */ + /** + * @state: BLK_MQ_S_* flags. Defines the state of the hw + * queue (active, scheduled to restart, stopped). + */ + unsigned long state; } ____cacheline_aligned_in_smp; + /** + * @run_work: Used for scheduling a hardware queue run at a later time. + */ struct delayed_work run_work; + /** @cpumask: Map of available CPUs where this hctx can run. */ cpumask_var_t cpumask; + /** + * @next_cpu: Used by blk_mq_hctx_next_cpu() for round-robin CPU + * selection from @cpumask. + */ int next_cpu; + /** + * @next_cpu_batch: Counter of how many works left in the batch before + * changing to the next CPU. + */ int next_cpu_batch; - unsigned long flags; /* BLK_MQ_F_* flags */ + /** @flags: BLK_MQ_F_* flags. Defines the behaviour of the queue. */ + unsigned long flags; + /** + * @sched_data: Pointer owned by the IO scheduler attached to a request + * queue. It's up to the IO scheduler how to use this pointer. + */ void *sched_data; + /** + * @queue: Pointer to the request queue that owns this hardware context. + */ struct request_queue *queue; + /** @fq: Queue of requests that need to perform a flush operation. */ struct blk_flush_queue *fq; + /** + * @driver_data: Pointer to data owned by the block driver that created + * this hctx + */ void *driver_data; + /** + * @ctx_map: Bitmap for each software queue. If bit is on, there is a + * pending request in that software queue. + */ struct sbitmap ctx_map; + /** + * @dispatch_from: Software queue to be used when no scheduler was + * selected. + */ struct blk_mq_ctx *dispatch_from; + /** + * @dispatch_busy: Number used by blk_mq_update_dispatch_busy() to + * decide if the hw_queue is busy using Exponential Weighted Moving + * Average algorithm. + */ unsigned int dispatch_busy; + /** @type: HCTX_TYPE_* flags. Type of hardware queue. */ unsigned short type; + /** @nr_ctx: Number of software queues. */ unsigned short nr_ctx; + /** @ctxs: Array of software queues. */ struct blk_mq_ctx **ctxs; + /** @dispatch_wait_lock: Lock for dispatch_wait queue. */ spinlock_t dispatch_wait_lock; + /** + * @dispatch_wait: Waitqueue to put requests when there is no tag + * available at the moment, to wait for another try in the future. + */ wait_queue_entry_t dispatch_wait; + + /** + * @wait_index: Index of next available dispatch_wait queue to insert + * requests. + */ atomic_t wait_index; + /** + * @tags: Tags owned by the block driver. A tag at this set is only + * assigned when a request is dispatched from a hardware queue. + */ struct blk_mq_tags *tags; + /** + * @sched_tags: Tags owned by I/O scheduler. If there is an I/O + * scheduler associated with a request queue, a tag is assigned when + * that request is allocated. Else, this member is not used. + */ struct blk_mq_tags *sched_tags; - unsigned long queued; - unsigned long run; -#define BLK_MQ_MAX_DISPATCH_ORDER 7 - unsigned long dispatched[BLK_MQ_MAX_DISPATCH_ORDER]; - + /** @numa_node: NUMA node the storage adapter has been connected to. */ unsigned int numa_node; + /** @queue_num: Index of this hardware queue. */ unsigned int queue_num; + /** + * @nr_active: Number of active requests. Only used when a tag set is + * shared across request queues. + */ atomic_t nr_active; - unsigned int nr_expired; + /** @cpuhp_online: List to store request if CPU is going to die */ + struct hlist_node cpuhp_online; + /** @cpuhp_dead: List to store request if some CPU die. */ struct hlist_node cpuhp_dead; + /** @kobj: Kernel object for sysfs. */ struct kobject kobj; - unsigned long poll_considered; - unsigned long poll_invoked; - unsigned long poll_success; - #ifdef CONFIG_BLK_DEBUG_FS + /** + * @debugfs_dir: debugfs directory for this hardware queue. Named + * as cpu<cpu_number>. + */ struct dentry *debugfs_dir; + /** @sched_debugfs_dir: debugfs directory for the scheduler. */ struct dentry *sched_debugfs_dir; #endif - /* Must be the last member - see also blk_mq_hw_ctx_size(). */ - struct srcu_struct srcu[0]; + /** + * @hctx_list: if this hctx is not in use, this is an entry in + * q->unused_hctx_list. + */ + struct list_head hctx_list; }; +/** + * struct blk_mq_queue_map - Map software queues to hardware queues + * @mq_map: CPU ID to hardware queue index map. This is an array + * with nr_cpu_ids elements. Each element has a value in the range + * [@queue_offset, @queue_offset + @nr_queues). + * @nr_queues: Number of hardware queues to map CPU IDs onto. + * @queue_offset: First hardware queue to map onto. Used by the PCIe NVMe + * driver to map each hardware queue type (enum hctx_type) onto a distinct + * set of hardware queues. + */ struct blk_mq_queue_map { unsigned int *mq_map; unsigned int nr_queues; unsigned int queue_offset; }; +/** + * enum hctx_type - Type of hardware queue + * @HCTX_TYPE_DEFAULT: All I/O not otherwise accounted for. + * @HCTX_TYPE_READ: Just for READ I/O. + * @HCTX_TYPE_POLL: Polled I/O of any kind. + * @HCTX_MAX_TYPES: Number of types of hctx. + */ enum hctx_type { - HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */ - HCTX_TYPE_READ, /* just for READ I/O */ - HCTX_TYPE_POLL, /* polled I/O of any kind */ + HCTX_TYPE_DEFAULT, + HCTX_TYPE_READ, + HCTX_TYPE_POLL, HCTX_MAX_TYPES, }; +/** + * struct blk_mq_tag_set - tag set that can be shared between request queues + * @ops: Pointers to functions that implement block driver behavior. + * @map: One or more ctx -> hctx mappings. One map exists for each + * hardware queue type (enum hctx_type) that the driver wishes + * to support. There are no restrictions on maps being of the + * same size, and it's perfectly legal to share maps between + * types. + * @nr_maps: Number of elements in the @map array. A number in the range + * [1, HCTX_MAX_TYPES]. + * @nr_hw_queues: Number of hardware queues supported by the block driver that + * owns this data structure. + * @queue_depth: Number of tags per hardware queue, reserved tags included. + * @reserved_tags: Number of tags to set aside for BLK_MQ_REQ_RESERVED tag + * allocations. + * @cmd_size: Number of additional bytes to allocate per request. The block + * driver owns these additional bytes. + * @numa_node: NUMA node the storage adapter has been connected to. + * @timeout: Request processing timeout in jiffies. + * @flags: Zero or more BLK_MQ_F_* flags. + * @driver_data: Pointer to data owned by the block driver that created this + * tag set. + * @tags: Tag sets. One tag set per hardware queue. Has @nr_hw_queues + * elements. + * @shared_tags: + * Shared set of tags. Has @nr_hw_queues elements. If set, + * shared by all @tags. + * @tag_list_lock: Serializes tag_list accesses. + * @tag_list: List of the request queues that use this tag set. See also + * request_queue.tag_set_list. + * @srcu: Use as lock when type of the request queue is blocking + * (BLK_MQ_F_BLOCKING). + * @tags_srcu: SRCU used to defer freeing of tags page_list to prevent + * use-after-free when iterating tags. + * @update_nr_hwq_lock: + * Synchronize updating nr_hw_queues with add/del disk & + * switching elevator. + */ struct blk_mq_tag_set { - /* - * map[] holds ctx -> hctx mappings, one map exists for each type - * that the driver wishes to support. There are no restrictions - * on maps being of the same size, and it's perfectly legal to - * share maps between types. - */ - struct blk_mq_queue_map map[HCTX_MAX_TYPES]; - unsigned int nr_maps; /* nr entries in map[] */ const struct blk_mq_ops *ops; - unsigned int nr_hw_queues; /* nr hw queues across maps */ - unsigned int queue_depth; /* max hw supported */ + struct blk_mq_queue_map map[HCTX_MAX_TYPES]; + unsigned int nr_maps; + unsigned int nr_hw_queues; + unsigned int queue_depth; unsigned int reserved_tags; - unsigned int cmd_size; /* per-request extra data */ + unsigned int cmd_size; int numa_node; unsigned int timeout; - unsigned int flags; /* BLK_MQ_F_* */ + unsigned int flags; void *driver_data; struct blk_mq_tags **tags; + struct blk_mq_tags *shared_tags; + struct mutex tag_list_lock; struct list_head tag_list; + struct srcu_struct *srcu; + struct srcu_struct tags_srcu; + + struct rw_semaphore update_nr_hwq_lock; }; +/** + * struct blk_mq_queue_data - Data about a request inserted in a queue + * + * @rq: Request pointer. + * @last: If it is the last request in the queue. + */ struct blk_mq_queue_data { struct request *rq; bool last; }; -typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *, - const struct blk_mq_queue_data *); -typedef void (commit_rqs_fn)(struct blk_mq_hw_ctx *); -typedef bool (get_budget_fn)(struct blk_mq_hw_ctx *); -typedef void (put_budget_fn)(struct blk_mq_hw_ctx *); -typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool); -typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); -typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int); -typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *, - unsigned int, unsigned int); -typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *, - unsigned int); - -typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *, - bool); -typedef bool (busy_tag_iter_fn)(struct request *, void *, bool); -typedef int (poll_fn)(struct blk_mq_hw_ctx *); -typedef int (map_queues_fn)(struct blk_mq_tag_set *set); -typedef bool (busy_fn)(struct request_queue *); -typedef void (complete_fn)(struct request *); - +typedef bool (busy_tag_iter_fn)(struct request *, void *); +/** + * struct blk_mq_ops - Callback functions that implements block driver + * behaviour. + */ struct blk_mq_ops { - /* - * Queue request + /** + * @queue_rq: Queue a new request from block IO. */ - queue_rq_fn *queue_rq; + blk_status_t (*queue_rq)(struct blk_mq_hw_ctx *, + const struct blk_mq_queue_data *); - /* - * If a driver uses bd->last to judge when to submit requests to - * hardware, it must define this function. In case of errors that - * make us stop issuing further requests, this hook serves the + /** + * @commit_rqs: If a driver uses bd->last to judge when to submit + * requests to hardware, it must define this function. In case of errors + * that make us stop issuing further requests, this hook serves the * purpose of kicking the hardware (which the last request otherwise * would have done). */ - commit_rqs_fn *commit_rqs; + void (*commit_rqs)(struct blk_mq_hw_ctx *); - /* - * Reserve budget before queue request, once .queue_rq is + /** + * @queue_rqs: Queue a list of new requests. Driver is guaranteed + * that each request belongs to the same queue. If the driver doesn't + * empty the @rqlist completely, then the rest will be queued + * individually by the block layer upon return. + */ + void (*queue_rqs)(struct rq_list *rqlist); + + /** + * @get_budget: Reserve budget before queue request, once .queue_rq is * run, it is driver's responsibility to release the * reserved budget. Also we have to handle failure case * of .get_budget for avoiding I/O deadlock. */ - get_budget_fn *get_budget; - put_budget_fn *put_budget; + int (*get_budget)(struct request_queue *); - /* - * Called on request timeout + /** + * @put_budget: Release the reserved budget. */ - timeout_fn *timeout; + void (*put_budget)(struct request_queue *, int); - /* - * Called to poll for completion of a specific tag. + /** + * @set_rq_budget_token: store rq's budget token + */ + void (*set_rq_budget_token)(struct request *, int); + /** + * @get_rq_budget_token: retrieve rq's budget token + */ + int (*get_rq_budget_token)(struct request *); + + /** + * @timeout: Called on request timeout. */ - poll_fn *poll; + enum blk_eh_timer_return (*timeout)(struct request *); - complete_fn *complete; + /** + * @poll: Called to poll for completion of a specific tag. + */ + int (*poll)(struct blk_mq_hw_ctx *, struct io_comp_batch *); - /* - * Called when the block layer side of a hardware queue has been - * set up, allowing the driver to allocate/init matching structures. - * Ditto for exit/teardown. + /** + * @complete: Mark the request as complete. */ - init_hctx_fn *init_hctx; - exit_hctx_fn *exit_hctx; + void (*complete)(struct request *); - /* - * Called for every command allocated by the block layer to allow - * the driver to set up driver specific data. + /** + * @init_hctx: Called when the block layer side of a hardware queue has + * been set up, allowing the driver to allocate/init matching + * structures. + */ + int (*init_hctx)(struct blk_mq_hw_ctx *, void *, unsigned int); + /** + * @exit_hctx: Ditto for exit/teardown. + */ + void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); + + /** + * @init_request: Called for every command allocated by the block layer + * to allow the driver to set up driver specific data. * * Tag greater than or equal to queue_depth is for setting up * flush request. - * - * Ditto for exit/teardown. */ - init_request_fn *init_request; - exit_request_fn *exit_request; - /* Called from inside blk_get_request() */ - void (*initialize_rq_fn)(struct request *rq); + int (*init_request)(struct blk_mq_tag_set *set, struct request *, + unsigned int, unsigned int); + /** + * @exit_request: Ditto for exit/teardown. + */ + void (*exit_request)(struct blk_mq_tag_set *set, struct request *, + unsigned int); - /* - * If set, returns whether or not this queue currently is busy + /** + * @cleanup_rq: Called before freeing one request which isn't completed + * yet, and usually for freeing the driver private data. */ - busy_fn *busy; + void (*cleanup_rq)(struct request *); - map_queues_fn *map_queues; + /** + * @busy: If set, returns whether or not this queue currently is busy. + */ + bool (*busy)(struct request_queue *); + + /** + * @map_queues: This allows drivers specify their own queue mapping by + * overriding the setup-time function that builds the mq_map. + */ + void (*map_queues)(struct blk_mq_tag_set *set); #ifdef CONFIG_BLK_DEBUG_FS - /* - * Used by the debugfs implementation to show driver-specific + /** + * @show_rq: Used by the debugfs implementation to show driver-specific * information about a request. */ void (*show_rq)(struct seq_file *m, struct request *rq); #endif }; +/* Keep hctx_flag_name[] in sync with the definitions below */ enum { - BLK_MQ_F_SHOULD_MERGE = 1 << 0, - BLK_MQ_F_TAG_SHARED = 1 << 1, - BLK_MQ_F_SG_MERGE = 1 << 2, - BLK_MQ_F_BLOCKING = 1 << 5, - BLK_MQ_F_NO_SCHED = 1 << 6, - BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, - BLK_MQ_F_ALLOC_POLICY_BITS = 1, + BLK_MQ_F_TAG_QUEUE_SHARED = 1 << 1, + /* + * Set when this device requires underlying blk-mq device for + * completing IO: + */ + BLK_MQ_F_STACKING = 1 << 2, + BLK_MQ_F_TAG_HCTX_SHARED = 1 << 3, + BLK_MQ_F_BLOCKING = 1 << 4, + + /* + * Alloc tags on a round-robin base instead of the first available one. + */ + BLK_MQ_F_TAG_RR = 1 << 5, - BLK_MQ_S_STOPPED = 0, - BLK_MQ_S_TAG_ACTIVE = 1, - BLK_MQ_S_SCHED_RESTART = 2, + /* + * Select 'none' during queue registration in case of a single hwq + * or shared hwqs instead of 'mq-deadline'. + */ + BLK_MQ_F_NO_SCHED_BY_DEFAULT = 1 << 6, - BLK_MQ_MAX_DEPTH = 10240, + BLK_MQ_F_MAX = 1 << 7, +}; - BLK_MQ_CPU_WORK_BATCH = 8, +#define BLK_MQ_MAX_DEPTH (10240) +#define BLK_MQ_NO_HCTX_IDX (-1U) + +enum { + /* Keep hctx_state_name[] in sync with the definitions below */ + BLK_MQ_S_STOPPED, + BLK_MQ_S_TAG_ACTIVE, + BLK_MQ_S_SCHED_RESTART, + /* hw queue is inactive after all its CPUs become offline */ + BLK_MQ_S_INACTIVE, + BLK_MQ_S_MAX }; -#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \ - ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \ - ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) -#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \ - ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \ - << BLK_MQ_F_ALLOC_POLICY_START_BIT) - -struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *); -struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, - struct request_queue *q); -struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, - const struct blk_mq_ops *ops, - unsigned int queue_depth, - unsigned int set_flags); -int blk_mq_register_dev(struct device *, struct request_queue *); -void blk_mq_unregister_dev(struct device *, struct request_queue *); + +struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata, + struct lock_class_key *lkclass); +#define blk_mq_alloc_disk(set, lim, queuedata) \ +({ \ + static struct lock_class_key __key; \ + \ + __blk_mq_alloc_disk(set, lim, queuedata, &__key); \ +}) +struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q, + struct lock_class_key *lkclass); +struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata); +int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, + struct request_queue *q); +void blk_mq_destroy_queue(struct request_queue *); int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set); +int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set, + const struct blk_mq_ops *ops, unsigned int queue_depth, + unsigned int set_flags); void blk_mq_free_tag_set(struct blk_mq_tag_set *set); -void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule); - void blk_mq_free_request(struct request *rq); -bool blk_mq_can_queue(struct blk_mq_hw_ctx *); +int blk_rq_poll(struct request *rq, struct io_comp_batch *iob, + unsigned int poll_flags); bool blk_mq_queue_inflight(struct request_queue *q); @@ -264,18 +756,49 @@ enum { BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0), /* allocate from reserved pool */ BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1), - /* allocate internal/sched tag */ - BLK_MQ_REQ_INTERNAL = (__force blk_mq_req_flags_t)(1 << 2), - /* set RQF_PREEMPT */ - BLK_MQ_REQ_PREEMPT = (__force blk_mq_req_flags_t)(1 << 3), + /* set RQF_PM */ + BLK_MQ_REQ_PM = (__force blk_mq_req_flags_t)(1 << 2), }; -struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, +struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf, blk_mq_req_flags_t flags); struct request *blk_mq_alloc_request_hctx(struct request_queue *q, - unsigned int op, blk_mq_req_flags_t flags, + blk_opf_t opf, blk_mq_req_flags_t flags, unsigned int hctx_idx); -struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag); + +/* + * Tag address space map. + */ +struct blk_mq_tags { + unsigned int nr_tags; + unsigned int nr_reserved_tags; + unsigned int active_queues; + + struct sbitmap_queue bitmap_tags; + struct sbitmap_queue breserved_tags; + + struct request **rqs; + struct request **static_rqs; + struct list_head page_list; + + /* + * used to clear request reference in rqs[] before freeing one + * request pool + */ + spinlock_t lock; + struct rcu_head rcu_head; +}; + +static inline struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, + unsigned int tag) +{ + if (tag < tags->nr_tags) { + prefetch(tags->rqs[tag]); + return tags->rqs[tag]; + } + + return NULL; +} enum { BLK_MQ_UNIQUE_TAG_BITS = 16, @@ -294,21 +817,115 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag) return unique_tag & BLK_MQ_UNIQUE_TAG_MASK; } +/** + * blk_mq_rq_state() - read the current MQ_RQ_* state of a request + * @rq: target request. + */ +static inline enum mq_rq_state blk_mq_rq_state(struct request *rq) +{ + return READ_ONCE(rq->state); +} + +static inline int blk_mq_request_started(struct request *rq) +{ + return blk_mq_rq_state(rq) != MQ_RQ_IDLE; +} + +static inline int blk_mq_request_completed(struct request *rq) +{ + return blk_mq_rq_state(rq) == MQ_RQ_COMPLETE; +} + +/* + * + * Set the state to complete when completing a request from inside ->queue_rq. + * This is used by drivers that want to ensure special complete actions that + * need access to the request are called on failure, e.g. by nvme for + * multipathing. + */ +static inline void blk_mq_set_request_complete(struct request *rq) +{ + WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); +} + +/* + * Complete the request directly instead of deferring it to softirq or + * completing it another CPU. Useful in preemptible instead of an interrupt. + */ +static inline void blk_mq_complete_request_direct(struct request *rq, + void (*complete)(struct request *rq)) +{ + WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); + complete(rq); +} -int blk_mq_request_started(struct request *rq); void blk_mq_start_request(struct request *rq); void blk_mq_end_request(struct request *rq, blk_status_t error); void __blk_mq_end_request(struct request *rq, blk_status_t error); +void blk_mq_end_request_batch(struct io_comp_batch *ib); + +/* + * Only need start/end time stamping if we have iostat or + * blk stats enabled, or using an IO scheduler. + */ +static inline bool blk_mq_need_time_stamp(struct request *rq) +{ + return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_USE_SCHED)); +} + +static inline bool blk_mq_is_reserved_rq(struct request *rq) +{ + return rq->rq_flags & RQF_RESV; +} + +/** + * blk_mq_add_to_batch() - add a request to the completion batch + * @req: The request to add to batch + * @iob: The batch to add the request + * @is_error: Specify true if the request failed with an error + * @complete: The completaion handler for the request + * + * Batched completions only work when there is no I/O error and no special + * ->end_io handler. + * + * Return: true when the request was added to the batch, otherwise false + */ +static inline bool blk_mq_add_to_batch(struct request *req, + struct io_comp_batch *iob, bool is_error, + void (*complete)(struct io_comp_batch *)) +{ + /* + * Check various conditions that exclude batch processing: + * 1) No batch container + * 2) Has scheduler data attached + * 3) Not a passthrough request and end_io set + * 4) Not a passthrough request and failed with an error + */ + if (!iob) + return false; + if (req->rq_flags & RQF_SCHED_TAGS) + return false; + if (!blk_rq_is_passthrough(req)) { + if (req->end_io) + return false; + if (is_error) + return false; + } + + if (!iob->complete) + iob->complete = complete; + else if (iob->complete != complete) + return false; + iob->need_ts |= blk_mq_need_time_stamp(req); + rq_list_add_tail(&iob->req_list, req); + return true; +} void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list); -void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, - bool kick_requeue_list); void blk_mq_kick_requeue_list(struct request_queue *q); void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); -bool blk_mq_complete_request(struct request *rq); -bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, - struct bio *bio); -bool blk_mq_queue_stopped(struct request_queue *q); +void blk_mq_complete_request(struct request *rq); +bool blk_mq_complete_request_remote(struct request *rq); void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_stop_hw_queues(struct request_queue *q); @@ -316,55 +933,312 @@ void blk_mq_start_hw_queues(struct request_queue *q); void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async); void blk_mq_quiesce_queue(struct request_queue *q); +void blk_mq_wait_quiesce_done(struct blk_mq_tag_set *set); +void blk_mq_quiesce_tagset(struct blk_mq_tag_set *set); +void blk_mq_unquiesce_tagset(struct blk_mq_tag_set *set); void blk_mq_unquiesce_queue(struct request_queue *q); void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs); -bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); +void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); void blk_mq_run_hw_queues(struct request_queue *q, bool async); +void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs); void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, busy_tag_iter_fn *fn, void *priv); -void blk_mq_freeze_queue(struct request_queue *q); -void blk_mq_unfreeze_queue(struct request_queue *q); +void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset); +void blk_mq_freeze_queue_nomemsave(struct request_queue *q); +void blk_mq_unfreeze_queue_nomemrestore(struct request_queue *q); +static inline unsigned int __must_check +blk_mq_freeze_queue(struct request_queue *q) +{ + unsigned int memflags = memalloc_noio_save(); + + blk_mq_freeze_queue_nomemsave(q); + return memflags; +} +static inline void +blk_mq_unfreeze_queue(struct request_queue *q, unsigned int memflags) +{ + blk_mq_unfreeze_queue_nomemrestore(q); + memalloc_noio_restore(memflags); +} void blk_freeze_queue_start(struct request_queue *q); void blk_mq_freeze_queue_wait(struct request_queue *q); int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, unsigned long timeout); - -int blk_mq_map_queues(struct blk_mq_queue_map *qmap); +void blk_mq_unfreeze_queue_non_owner(struct request_queue *q); +void blk_freeze_queue_start_non_owner(struct request_queue *q); + +unsigned int blk_mq_num_possible_queues(unsigned int max_queues); +unsigned int blk_mq_num_online_queues(unsigned int max_queues); +void blk_mq_map_queues(struct blk_mq_queue_map *qmap); +void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap, + struct device *dev, unsigned int offset); void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); void blk_mq_quiesce_queue_nowait(struct request_queue *q); unsigned int blk_mq_rq_cpu(struct request *rq); -/* +bool __blk_should_fake_timeout(struct request_queue *q); +static inline bool blk_should_fake_timeout(struct request_queue *q) +{ + if (IS_ENABLED(CONFIG_FAIL_IO_TIMEOUT) && + test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags)) + return __blk_should_fake_timeout(q); + return false; +} + +/** + * blk_mq_rq_from_pdu - cast a PDU to a request + * @pdu: the PDU (Protocol Data Unit) to be casted + * + * Return: request + * * Driver command data is immediately after the request. So subtract request - * size to get back to the original request, add request size to get the PDU. + * size to get back to the original request. */ static inline struct request *blk_mq_rq_from_pdu(void *pdu) { return pdu - sizeof(struct request); } + +/** + * blk_mq_rq_to_pdu - cast a request to a PDU + * @rq: the request to be casted + * + * Return: pointer to the PDU + * + * Driver command data is immediately after the request. So add request to get + * the PDU. + */ static inline void *blk_mq_rq_to_pdu(struct request *rq) { return rq + 1; } +static inline struct blk_mq_hw_ctx *queue_hctx(struct request_queue *q, int id) +{ + struct blk_mq_hw_ctx *hctx; + + rcu_read_lock(); + hctx = rcu_dereference(q->queue_hw_ctx)[id]; + rcu_read_unlock(); + + return hctx; +} + #define queue_for_each_hw_ctx(q, hctx, i) \ for ((i) = 0; (i) < (q)->nr_hw_queues && \ - ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++) + ({ hctx = queue_hctx((q), i); 1; }); (i)++) #define hctx_for_each_ctx(hctx, ctx, i) \ for ((i) = 0; (i) < (hctx)->nr_ctx && \ ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++) -static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, - struct request *rq) +static inline void blk_mq_cleanup_rq(struct request *rq) { - if (rq->tag != -1) - return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT); + if (rq->q->mq_ops->cleanup_rq) + rq->q->mq_ops->cleanup_rq(rq); +} + +void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx, + struct lock_class_key *key); - return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) | - BLK_QC_T_INTERNAL; +static inline bool rq_is_sync(struct request *rq) +{ + return op_is_sync(rq->cmd_flags); } -#endif +void blk_rq_init(struct request_queue *q, struct request *rq); +int blk_rq_prep_clone(struct request *rq, struct request *rq_src, + struct bio_set *bs, gfp_t gfp_mask, + int (*bio_ctr)(struct bio *, struct bio *, void *), void *data); +void blk_rq_unprep_clone(struct request *rq); +blk_status_t blk_insert_cloned_request(struct request *rq); + +struct rq_map_data { + struct page **pages; + unsigned long offset; + unsigned short page_order; + unsigned short nr_entries; + bool null_mapped; + bool from_user; +}; + +int blk_rq_map_user(struct request_queue *, struct request *, + struct rq_map_data *, void __user *, unsigned long, gfp_t); +int blk_rq_map_user_io(struct request *, struct rq_map_data *, + void __user *, unsigned long, gfp_t, bool, int, bool, int); +int blk_rq_map_user_iov(struct request_queue *, struct request *, + struct rq_map_data *, const struct iov_iter *, gfp_t); +int blk_rq_unmap_user(struct bio *); +int blk_rq_map_kern(struct request *rq, void *kbuf, unsigned int len, + gfp_t gfp); +int blk_rq_append_bio(struct request *rq, struct bio *bio); +void blk_execute_rq_nowait(struct request *rq, bool at_head); +blk_status_t blk_execute_rq(struct request *rq, bool at_head); +bool blk_rq_is_poll(struct request *rq); + +struct req_iterator { + struct bvec_iter iter; + struct bio *bio; +}; + +#define __rq_for_each_bio(_bio, rq) \ + if ((rq->bio)) \ + for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) + +#define rq_for_each_segment(bvl, _rq, _iter) \ + __rq_for_each_bio(_iter.bio, _rq) \ + bio_for_each_segment(bvl, _iter.bio, _iter.iter) + +#define rq_for_each_bvec(bvl, _rq, _iter) \ + __rq_for_each_bio(_iter.bio, _rq) \ + bio_for_each_bvec(bvl, _iter.bio, _iter.iter) + +#define rq_iter_last(bvec, _iter) \ + (_iter.bio->bi_next == NULL && \ + bio_iter_last(bvec, _iter.iter)) + +/* + * blk_rq_pos() : the current sector + * blk_rq_bytes() : bytes left in the entire request + * blk_rq_cur_bytes() : bytes left in the current segment + * blk_rq_sectors() : sectors left in the entire request + * blk_rq_cur_sectors() : sectors left in the current segment + * blk_rq_stats_sectors() : sectors of the entire request used for stats + */ +static inline sector_t blk_rq_pos(const struct request *rq) +{ + return rq->__sector; +} + +static inline unsigned int blk_rq_bytes(const struct request *rq) +{ + return rq->__data_len; +} + +static inline int blk_rq_cur_bytes(const struct request *rq) +{ + if (!rq->bio) + return 0; + if (!bio_has_data(rq->bio)) /* dataless requests such as discard */ + return rq->bio->bi_iter.bi_size; + return bio_iovec(rq->bio).bv_len; +} + +static inline unsigned int blk_rq_sectors(const struct request *rq) +{ + return blk_rq_bytes(rq) >> SECTOR_SHIFT; +} + +static inline unsigned int blk_rq_cur_sectors(const struct request *rq) +{ + return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT; +} + +static inline unsigned int blk_rq_stats_sectors(const struct request *rq) +{ + return rq->stats_sectors; +} + +/* + * 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 + * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to + * calculate the data transfer size. + */ +static inline unsigned int blk_rq_payload_bytes(struct request *rq) +{ + if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) + return rq->special_vec.bv_len; + return blk_rq_bytes(rq); +} + +/* + * Return the first full biovec in the request. The caller needs to check that + * there are any bvecs before calling this helper. + */ +static inline struct bio_vec req_bvec(struct request *rq) +{ + if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) + return rq->special_vec; + return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter); +} + +static inline unsigned int blk_rq_count_bios(struct request *rq) +{ + unsigned int nr_bios = 0; + struct bio *bio; + + __rq_for_each_bio(bio, rq) + nr_bios++; + + return nr_bios; +} + +void blk_steal_bios(struct bio_list *list, struct request *rq); + +/* + * Request completion related functions. + * + * blk_update_request() completes given number of bytes and updates + * the request without completing it. + */ +bool blk_update_request(struct request *rq, blk_status_t error, + unsigned int nr_bytes); +void blk_abort_request(struct request *); + +/* + * Number of physical segments as sent to the device. + * + * Normally this is the number of discontiguous data segments sent by the + * submitter. But for data-less command like discard we might have no + * actual data segments submitted, but the driver might have to add it's + * own special payload. In that case we still return 1 here so that this + * special payload will be mapped. + */ +static inline unsigned short blk_rq_nr_phys_segments(struct request *rq) +{ + if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) + return 1; + return rq->nr_phys_segments; +} + +/* + * Number of discard segments (or ranges) the driver needs to fill in. + * Each discard bio merged into a request is counted as one segment. + */ +static inline unsigned short blk_rq_nr_discard_segments(struct request *rq) +{ + return max_t(unsigned short, rq->nr_phys_segments, 1); +} + +/** + * blk_rq_nr_bvec - return number of bvecs in a request + * @rq: request to calculate bvecs for + * + * Returns the number of bvecs. + */ +static inline unsigned int blk_rq_nr_bvec(struct request *rq) +{ + struct req_iterator rq_iter; + struct bio_vec bv; + unsigned int nr_bvec = 0; + + rq_for_each_bvec(bv, rq, rq_iter) + nr_bvec++; + + return nr_bvec; +} + +int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist, + struct scatterlist **last_sg); +static inline int blk_rq_map_sg(struct request *rq, struct scatterlist *sglist) +{ + struct scatterlist *last_sg = NULL; + + return __blk_rq_map_sg(rq, sglist, &last_sg); +} +void blk_dump_rq_flags(struct request *, char *); + +#endif /* BLK_MQ_H */ |