diff options
Diffstat (limited to 'block/blk.h')
| -rw-r--r-- | block/blk.h | 820 |
1 files changed, 820 insertions, 0 deletions
diff --git a/block/blk.h b/block/blk.h new file mode 100644 index 000000000..50abfd932 --- /dev/null +++ b/block/blk.h @@ -0,0 +1,820 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BLK_INTERNAL_H +#define BLK_INTERNAL_H + +#include <linux/bio-integrity.h> +#include <linux/blk-crypto.h> +#include <linux/part_stat.h> +#include <linux/lockdep.h> +#include <linux/memblock.h> /* for max_pfn/max_low_pfn */ +#include <linux/sched/sysctl.h> +#include <linux/timekeeping.h> +#include <xen/xen.h> +#include "blk-crypto-internal.h" + +struct elv_change_ctx; + +/* + * Default upper limit for the software max_sectors limit used for regular I/Os. + * This can be increased through sysfs. + * + * This should not be confused with the max_hw_sector limit that is entirely + * controlled by the block device driver, usually based on hardware limits. + */ +#define BLK_DEF_MAX_SECTORS_CAP (SZ_4M >> SECTOR_SHIFT) + +#define BLK_DEV_MAX_SECTORS (LLONG_MAX >> 9) +#define BLK_MIN_SEGMENT_SIZE 4096 + +/* Max future timer expiry for timeouts */ +#define BLK_MAX_TIMEOUT (5 * HZ) + +extern const struct kobj_type blk_queue_ktype; +extern struct dentry *blk_debugfs_root; + +struct blk_flush_queue { + spinlock_t mq_flush_lock; + unsigned int flush_pending_idx:1; + unsigned int flush_running_idx:1; + blk_status_t rq_status; + unsigned long flush_pending_since; + struct list_head flush_queue[2]; + unsigned long flush_data_in_flight; + struct request *flush_rq; + struct rcu_head rcu_head; +}; + +bool is_flush_rq(struct request *req); + +struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, + gfp_t flags); +void blk_free_flush_queue(struct blk_flush_queue *q); + +const char *blk_status_to_str(blk_status_t status); +const char *blk_status_to_tag(blk_status_t status); +blk_status_t tag_to_blk_status(const char *tag); +enum req_op str_to_blk_op(const char *op); + +bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic); +bool blk_queue_start_drain(struct request_queue *q); +bool __blk_freeze_queue_start(struct request_queue *q, + struct task_struct *owner); +int __bio_queue_enter(struct request_queue *q, struct bio *bio); +void submit_bio_noacct_nocheck(struct bio *bio, bool split); +int bio_submit_or_kill(struct bio *bio, unsigned int flags); + +static inline bool blk_try_enter_queue(struct request_queue *q, bool pm) +{ + rcu_read_lock(); + if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter)) + goto fail; + + /* + * The code that increments the pm_only counter must ensure that the + * counter is globally visible before the queue is unfrozen. + */ + if (blk_queue_pm_only(q) && + (!pm || queue_rpm_status(q) == RPM_SUSPENDED)) + goto fail_put; + + rcu_read_unlock(); + return true; + +fail_put: + blk_queue_exit(q); +fail: + rcu_read_unlock(); + return false; +} + +static inline int bio_queue_enter(struct bio *bio) +{ + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + + if (blk_try_enter_queue(q, false)) { + rwsem_acquire_read(&q->io_lockdep_map, 0, 0, _RET_IP_); + rwsem_release(&q->io_lockdep_map, _RET_IP_); + return 0; + } + return __bio_queue_enter(q, bio); +} + +static inline void blk_wait_io(struct completion *done) +{ + /* Prevent hang_check timer from firing at us during very long I/O */ + unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; + + if (timeout) + while (!wait_for_completion_io_timeout(done, timeout)) + ; + else + wait_for_completion_io(done); +} + +struct block_device *blkdev_get_no_open(dev_t dev, bool autoload); +void blkdev_put_no_open(struct block_device *bdev); + +bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv, + struct page *page, unsigned len, unsigned offset); + +static inline bool biovec_phys_mergeable(struct request_queue *q, + struct bio_vec *vec1, struct bio_vec *vec2) +{ + unsigned long mask = queue_segment_boundary(q); + phys_addr_t addr1 = bvec_phys(vec1); + phys_addr_t addr2 = bvec_phys(vec2); + + /* + * Merging adjacent physical pages may not work correctly under KMSAN + * if their metadata pages aren't adjacent. Just disable merging. + */ + if (IS_ENABLED(CONFIG_KMSAN)) + return false; + + if (addr1 + vec1->bv_len != addr2) + return false; + if (!zone_device_pages_have_same_pgmap(vec1->bv_page, vec2->bv_page)) + return false; + if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page)) + return false; + if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask)) + return false; + return true; +} + +/* + * Check if two pages from potentially different zone device pgmaps can + * coexist as separate bvec entries in the same bio. + * + * The block DMA iterator (blk_dma_map_iter_start) caches the P2PDMA mapping + * state from the first segment and applies it to all subsequent segments, so + * P2PDMA pages from different pgmaps must not be mixed in the same bio. + * + * Other zone device types (FS_DAX, GENERIC) use the same dma_map_phys() path + * as normal RAM. PRIVATE and COHERENT pages never appear in bios. + */ +static inline bool zone_device_pages_compatible(const struct page *a, + const struct page *b) +{ + if (is_pci_p2pdma_page(a) || is_pci_p2pdma_page(b)) + return zone_device_pages_have_same_pgmap(a, b); + return true; +} + +static inline bool __bvec_gap_to_prev(const struct queue_limits *lim, + struct bio_vec *bprv, unsigned int offset) +{ + return (offset & lim->virt_boundary_mask) || + ((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask); +} + +/* + * Check if adding a bio_vec after bprv with offset would create a gap in + * the SG list. Most drivers don't care about this, but some do. + */ +static inline bool bvec_gap_to_prev(const struct queue_limits *lim, + struct bio_vec *bprv, unsigned int offset) +{ + if (!lim->virt_boundary_mask) + return false; + return __bvec_gap_to_prev(lim, bprv, offset); +} + +static inline bool rq_mergeable(struct request *rq) +{ + if (blk_rq_is_passthrough(rq)) + return false; + + if (req_op(rq) == REQ_OP_FLUSH) + return false; + + if (req_op(rq) == REQ_OP_WRITE_ZEROES) + return false; + + if (req_op(rq) == REQ_OP_ZONE_APPEND) + return false; + + if (rq->cmd_flags & REQ_NOMERGE_FLAGS) + return false; + if (rq->rq_flags & RQF_NOMERGE_FLAGS) + return false; + + return true; +} + +/* + * There are two different ways to handle DISCARD merges: + * 1) If max_discard_segments > 1, the driver treats every bio as a range and + * send the bios to controller together. The ranges don't need to be + * contiguous. + * 2) Otherwise, the request will be normal read/write requests. The ranges + * need to be contiguous. + */ +static inline bool blk_discard_mergable(struct request *req) +{ + if (req_op(req) == REQ_OP_DISCARD && + queue_max_discard_segments(req->q) > 1) + return true; + return false; +} + +static inline unsigned int blk_rq_get_max_segments(struct request *rq) +{ + if (req_op(rq) == REQ_OP_DISCARD) + return queue_max_discard_segments(rq->q); + return queue_max_segments(rq->q); +} + +static inline unsigned int blk_queue_get_max_sectors(struct request *rq) +{ + struct request_queue *q = rq->q; + enum req_op op = req_op(rq); + + if (unlikely(op == REQ_OP_DISCARD)) + return min(q->limits.max_discard_sectors, + UINT_MAX >> SECTOR_SHIFT); + + if (unlikely(op == REQ_OP_SECURE_ERASE)) + return min(q->limits.max_secure_erase_sectors, + UINT_MAX >> SECTOR_SHIFT); + + if (unlikely(op == REQ_OP_WRITE_ZEROES)) + return q->limits.max_write_zeroes_sectors; + + if (rq->cmd_flags & REQ_ATOMIC) + return q->limits.atomic_write_max_sectors; + + return q->limits.max_sectors; +} + +#ifdef CONFIG_BLK_DEV_INTEGRITY +void blk_flush_integrity(void); +void bio_integrity_free(struct bio *bio); + +/* + * Integrity payloads can either be owned by the submitter, in which case + * bio_uninit will free them, or owned and generated by the block layer, + * in which case we'll verify them here (for reads) and free them before + * the bio is handed back to the submitted. + */ +bool __bio_integrity_endio(struct bio *bio); +static inline bool bio_integrity_endio(struct bio *bio) +{ + struct bio_integrity_payload *bip = bio_integrity(bio); + + if (bip && (bip->bip_flags & BIP_BLOCK_INTEGRITY)) + return __bio_integrity_endio(bio); + return true; +} + +bool blk_integrity_merge_rq(struct request_queue *, struct request *, + struct request *); +bool blk_integrity_merge_bio(struct request_queue *, struct request *, + struct bio *); + +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + struct bio_integrity_payload *bip = bio_integrity(req->bio); + struct bio_integrity_payload *bip_next = bio_integrity(next); + + return bvec_gap_to_prev(&req->q->limits, + &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} + +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + struct bio_integrity_payload *bip = bio_integrity(bio); + struct bio_integrity_payload *bip_next = bio_integrity(req->bio); + + return bvec_gap_to_prev(&req->q->limits, + &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} + +extern const struct attribute_group blk_integrity_attr_group; +#else /* CONFIG_BLK_DEV_INTEGRITY */ +static inline bool blk_integrity_merge_rq(struct request_queue *rq, + struct request *r1, struct request *r2) +{ + return true; +} +static inline bool blk_integrity_merge_bio(struct request_queue *rq, + struct request *r, struct bio *b) +{ + return true; +} +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + return false; +} +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + return false; +} + +static inline void blk_flush_integrity(void) +{ +} +static inline bool bio_integrity_endio(struct bio *bio) +{ + return true; +} +static inline void bio_integrity_free(struct bio *bio) +{ +} +#endif /* CONFIG_BLK_DEV_INTEGRITY */ + +unsigned long blk_rq_timeout(unsigned long timeout); +void blk_add_timer(struct request *req); + +enum bio_merge_status { + BIO_MERGE_OK, + BIO_MERGE_NONE, + BIO_MERGE_FAILED, +}; + +enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, unsigned int nr_segs); +bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, + unsigned int nr_segs); +bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, + struct bio *bio, unsigned int nr_segs); + +/* + * Plug flush limits + */ +#define BLK_MAX_REQUEST_COUNT 32 +#define BLK_PLUG_FLUSH_SIZE (128 * 1024) + +/* + * Internal elevator interface + */ +#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED) + +bool blk_insert_flush(struct request *rq); + +void elv_update_nr_hw_queues(struct request_queue *q, + struct elv_change_ctx *ctx); +void elevator_set_default(struct request_queue *q); +void elevator_set_none(struct request_queue *q); + +ssize_t part_size_show(struct device *dev, struct device_attribute *attr, + char *buf); +ssize_t part_stat_show(struct device *dev, struct device_attribute *attr, + char *buf); +ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, + char *buf); +ssize_t part_fail_show(struct device *dev, struct device_attribute *attr, + char *buf); +ssize_t part_fail_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count); +ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); +ssize_t part_timeout_store(struct device *, struct device_attribute *, + const char *, size_t); + +struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim, + unsigned *nsegs); +struct bio *bio_split_write_zeroes(struct bio *bio, + const struct queue_limits *lim, unsigned *nsegs); +struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim, + unsigned *nr_segs); +struct bio *bio_split_zone_append(struct bio *bio, + const struct queue_limits *lim, unsigned *nr_segs); + +/* + * All drivers must accept single-segments bios that are smaller than PAGE_SIZE. + * + * This is a quick and dirty check that relies on the fact that bi_io_vec[0] is + * always valid if a bio has data. The check might lead to occasional false + * positives when bios are cloned, but compared to the performance impact of + * cloned bios themselves the loop below doesn't matter anyway. + */ +static inline bool bio_may_need_split(struct bio *bio, + const struct queue_limits *lim) +{ + const struct bio_vec *bv; + + if (lim->chunk_sectors) + return true; + + if (!bio->bi_io_vec) + return true; + + bv = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); + if (bio->bi_iter.bi_size > bv->bv_len - bio->bi_iter.bi_offset) + return true; + if ((bv->bv_offset | bv->bv_len) & lim->dma_alignment) + return true; + return bv->bv_len + bv->bv_offset > lim->max_fast_segment_size; +} + +/** + * __bio_split_to_limits - split a bio to fit the queue limits + * @bio: bio to be split + * @lim: queue limits to split based on + * @nr_segs: returns the number of segments in the returned bio + * + * Check if @bio needs splitting based on the queue limits, and if so split off + * a bio fitting the limits from the beginning of @bio and return it. @bio is + * shortened to the remainder and re-submitted. + * + * The split bio is allocated from @q->bio_split, which is provided by the + * block layer. + */ +static inline struct bio *__bio_split_to_limits(struct bio *bio, + const struct queue_limits *lim, unsigned int *nr_segs) +{ + switch (bio_op(bio)) { + case REQ_OP_READ: + case REQ_OP_WRITE: + if (bio_may_need_split(bio, lim)) + return bio_split_rw(bio, lim, nr_segs); + *nr_segs = 1; + return bio; + case REQ_OP_ZONE_APPEND: + return bio_split_zone_append(bio, lim, nr_segs); + case REQ_OP_DISCARD: + case REQ_OP_SECURE_ERASE: + return bio_split_discard(bio, lim, nr_segs); + case REQ_OP_WRITE_ZEROES: + return bio_split_write_zeroes(bio, lim, nr_segs); + default: + /* other operations can't be split */ + *nr_segs = 0; + return bio; + } +} + +/** + * get_max_segment_size() - maximum number of bytes to add as a single segment + * @lim: Request queue limits. + * @paddr: address of the range to add + * @len: maximum length available to add at @paddr + * + * Returns the maximum number of bytes of the range starting at @paddr that can + * be added to a single segment. + */ +static inline unsigned get_max_segment_size(const struct queue_limits *lim, + phys_addr_t paddr, unsigned int len) +{ + /* + * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 + * after having calculated the minimum. + */ + return min_t(unsigned long, len, + min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr), + (unsigned long)lim->max_segment_size - 1) + 1); +} + +int ll_back_merge_fn(struct request *req, struct bio *bio, + unsigned int nr_segs); +bool blk_attempt_req_merge(struct request_queue *q, struct request *rq, + struct request *next); +unsigned int blk_recalc_rq_segments(struct request *rq); +bool blk_rq_merge_ok(struct request *rq, struct bio *bio); +enum elv_merge blk_try_merge(struct request *rq, struct bio *bio); + +int blk_set_default_limits(struct queue_limits *lim); +void blk_apply_bdi_limits(struct backing_dev_info *bdi, + struct queue_limits *lim); +int blk_dev_init(void); + +void update_io_ticks(struct block_device *part, unsigned long now, bool end); + +static inline void req_set_nomerge(struct request_queue *q, struct request *req) +{ + req->cmd_flags |= REQ_NOMERGE; + if (req == q->last_merge) + q->last_merge = NULL; +} + +static inline void bdev_inc_in_flight(struct block_device *bdev, + enum req_op op) +{ + bool rw = op_is_write(op); + + part_stat_local_inc(bdev, in_flight[rw]); + if (bdev_is_partition(bdev)) + part_stat_local_inc(bdev_whole(bdev), in_flight[rw]); +} + +static inline void bdev_dec_in_flight(struct block_device *bdev, + enum req_op op) +{ + bool rw = op_is_write(op); + + part_stat_local_dec(bdev, in_flight[rw]); + if (bdev_is_partition(bdev)) + part_stat_local_dec(bdev_whole(bdev), in_flight[rw]); +} + +/* + * Internal io_context interface + */ +struct io_cq *ioc_find_get_icq(struct request_queue *q); +struct io_cq *ioc_lookup_icq(struct request_queue *q); +#ifdef CONFIG_BLK_ICQ +void ioc_clear_queue(struct request_queue *q); +#else +static inline void ioc_clear_queue(struct request_queue *q) +{ +} +#endif /* CONFIG_BLK_ICQ */ + +#ifdef CONFIG_BLK_DEV_ZONED +void disk_init_zone_resources(struct gendisk *disk); +void disk_release_zone_resources(struct gendisk *disk); +static inline bool bio_zone_write_plugging(struct bio *bio) +{ + return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING); +} +static inline bool blk_req_bio_is_zone_append(struct request *rq, + struct bio *bio) +{ + return req_op(rq) == REQ_OP_ZONE_APPEND || + bio_flagged(bio, BIO_EMULATES_ZONE_APPEND); +} +void blk_zone_write_plug_bio_merged(struct bio *bio); +void blk_zone_write_plug_init_request(struct request *rq); +void blk_zone_append_update_request_bio(struct request *rq, struct bio *bio); +void blk_zone_mgmt_bio_endio(struct bio *bio); +void blk_zone_write_plug_bio_endio(struct bio *bio); +static inline void blk_zone_bio_endio(struct bio *bio) +{ + /* + * Zone management BIOs may impact zone write plugs (e.g. a zone reset + * changes a zone write plug zone write pointer offset), but these + * operation do not go through zone write plugging as they may operate + * on zones that do not have a zone write + * plug. blk_zone_mgmt_bio_endio() handles the potential changes to zone + * write plugs that are present. + */ + if (op_is_zone_mgmt(bio_op(bio))) { + blk_zone_mgmt_bio_endio(bio); + return; + } + + /* + * For write BIOs to zoned devices, signal the completion of the BIO so + * that the next write BIO can be submitted by zone write plugging. + */ + if (bio_zone_write_plugging(bio)) + blk_zone_write_plug_bio_endio(bio); +} + +void blk_zone_write_plug_finish_request(struct request *rq); +static inline void blk_zone_finish_request(struct request *rq) +{ + if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING) + blk_zone_write_plug_finish_request(rq); +} +int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd, + unsigned long arg); +int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode, + unsigned int cmd, unsigned long arg); +#else /* CONFIG_BLK_DEV_ZONED */ +static inline void disk_init_zone_resources(struct gendisk *disk) +{ +} +static inline void disk_release_zone_resources(struct gendisk *disk) +{ +} +static inline bool bio_zone_write_plugging(struct bio *bio) +{ + return false; +} +static inline bool blk_req_bio_is_zone_append(struct request *req, + struct bio *bio) +{ + return false; +} +static inline void blk_zone_write_plug_bio_merged(struct bio *bio) +{ +} +static inline void blk_zone_write_plug_init_request(struct request *rq) +{ +} +static inline void blk_zone_append_update_request_bio(struct request *rq, + struct bio *bio) +{ +} +static inline void blk_zone_bio_endio(struct bio *bio) +{ +} +static inline void blk_zone_finish_request(struct request *rq) +{ +} +static inline int blkdev_report_zones_ioctl(struct block_device *bdev, + unsigned int cmd, unsigned long arg) +{ + return -ENOTTY; +} +static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev, + blk_mode_t mode, unsigned int cmd, unsigned long arg) +{ + return -ENOTTY; +} +#endif /* CONFIG_BLK_DEV_ZONED */ + +struct block_device *bdev_alloc(struct gendisk *disk, u8 partno); +void bdev_add(struct block_device *bdev, dev_t dev); +void bdev_unhash(struct block_device *bdev); +void bdev_drop(struct block_device *bdev); + +int blk_alloc_ext_minor(void); +void blk_free_ext_minor(unsigned int minor); +#define ADDPART_FLAG_NONE 0 +#define ADDPART_FLAG_RAID 1 +#define ADDPART_FLAG_WHOLEDISK 2 +#define ADDPART_FLAG_READONLY 4 +int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, + sector_t length); +int bdev_del_partition(struct gendisk *disk, int partno); +int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start, + sector_t length); +void drop_partition(struct block_device *part); + +void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors); + +struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, + struct lock_class_key *lkclass); +struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id); + +int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode); + +int disk_alloc_events(struct gendisk *disk); +void disk_add_events(struct gendisk *disk); +void disk_del_events(struct gendisk *disk); +void disk_release_events(struct gendisk *disk); +void disk_block_events(struct gendisk *disk); +void disk_unblock_events(struct gendisk *disk); +void disk_flush_events(struct gendisk *disk, unsigned int mask); +extern struct device_attribute dev_attr_events; +extern struct device_attribute dev_attr_events_async; +extern struct device_attribute dev_attr_events_poll_msecs; + +extern struct attribute_group blk_trace_attr_group; + +blk_mode_t file_to_blk_mode(struct file *file); +int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode, + loff_t lstart, loff_t lend); +long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg); +int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags); +long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg); + +extern const struct address_space_operations def_blk_aops; + +int disk_register_independent_access_ranges(struct gendisk *disk); +void disk_unregister_independent_access_ranges(struct gendisk *disk); + +int should_fail_bio(struct bio *bio); +#ifdef CONFIG_FAIL_MAKE_REQUEST +bool should_fail_request(struct block_device *part, unsigned int bytes); +#else /* CONFIG_FAIL_MAKE_REQUEST */ +static inline bool should_fail_request(struct block_device *part, + unsigned int bytes) +{ + return false; +} +#endif /* CONFIG_FAIL_MAKE_REQUEST */ + +/* + * Optimized request reference counting. Ideally we'd make timeouts be more + * clever, as that's the only reason we need references at all... But until + * this happens, this is faster than using refcount_t. Also see: + * + * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count") + */ +#define req_ref_zero_or_close_to_overflow(req) \ + ((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u) + +static inline bool req_ref_inc_not_zero(struct request *req) +{ + return atomic_inc_not_zero(&req->ref); +} + +static inline bool req_ref_put_and_test(struct request *req) +{ + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + return atomic_dec_and_test(&req->ref); +} + +static inline void req_ref_set(struct request *req, int value) +{ + atomic_set(&req->ref, value); +} + +static inline int req_ref_read(struct request *req) +{ + return atomic_read(&req->ref); +} + +static inline u64 blk_time_get_ns(void) +{ + struct blk_plug *plug = current->plug; + u64 now; + + if (!plug || !in_task()) + return ktime_get_ns(); + + /* + * 0 could very well be a valid time, but rather than flag "this is + * a valid timestamp" separately, just accept that we'll do an extra + * ktime_get_ns() if we just happen to get 0 as the current time. + * + * cur_ktime can be zeroed by pre-emption the moment PF_BLOCK_TS is set. + */ + now = READ_ONCE(plug->cur_ktime); + if (!now) { + now = ktime_get_ns(); + WRITE_ONCE(plug->cur_ktime, now); + /* Ensure PF_BLOCK_TS is set after cur_ktime. */ + barrier(); + current->flags |= PF_BLOCK_TS; + } + return now; +} + +static inline ktime_t blk_time_get(void) +{ + return ns_to_ktime(blk_time_get_ns()); +} + +void bdev_release(struct file *bdev_file); +int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops, struct file *bdev_file); +int bdev_permission(dev_t dev, blk_mode_t mode, void *holder); + +void bio_integrity_generate(struct bio *bio); +blk_status_t bio_integrity_verify(struct bio *bio, + struct bvec_iter *saved_iter); + +void blk_integrity_prepare(struct request *rq); +void blk_integrity_complete(struct request *rq, unsigned int nr_bytes); + +#ifdef CONFIG_LOCKDEP +static inline void blk_freeze_acquire_lock(struct request_queue *q) +{ + if (!q->mq_freeze_disk_dead) + rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_); + if (!q->mq_freeze_queue_dying) + rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_); +} + +static inline void blk_unfreeze_release_lock(struct request_queue *q) +{ + if (!q->mq_freeze_queue_dying) + rwsem_release(&q->q_lockdep_map, _RET_IP_); + if (!q->mq_freeze_disk_dead) + rwsem_release(&q->io_lockdep_map, _RET_IP_); +} +#else +static inline void blk_freeze_acquire_lock(struct request_queue *q) +{ +} +static inline void blk_unfreeze_release_lock(struct request_queue *q) +{ +} +#endif + +/* + * debugfs directory and file creation can trigger fs reclaim, which can enter + * back into the block layer request_queue. This can cause deadlock if the + * queue is frozen. Use NOIO context together with debugfs_mutex to prevent fs + * reclaim from triggering block I/O. + */ +static inline void blk_debugfs_lock_nomemsave(struct request_queue *q) + __acquires(&q->debugfs_mutex) +{ + mutex_lock(&q->debugfs_mutex); +} + +static inline void blk_debugfs_unlock_nomemrestore(struct request_queue *q) + __releases(&q->debugfs_mutex) +{ + mutex_unlock(&q->debugfs_mutex); +} + +static inline unsigned int __must_check blk_debugfs_lock(struct request_queue *q) + __acquires(&q->debugfs_mutex) +{ + unsigned int memflags = memalloc_noio_save(); + + blk_debugfs_lock_nomemsave(q); + return memflags; +} + +static inline void blk_debugfs_unlock(struct request_queue *q, + unsigned int memflags) + __releases(&q->debugfs_mutex) +{ + blk_debugfs_unlock_nomemrestore(q); + memalloc_noio_restore(memflags); +} + +#endif /* BLK_INTERNAL_H */ |