![Christoph Hellwig](/assets/img/avatar_default.png)
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
275 lines
8.5 KiB
C
275 lines
8.5 KiB
C
/*
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* Block data types and constants. Directly include this file only to
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* break include dependency loop.
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*/
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#ifndef __LINUX_BLK_TYPES_H
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#define __LINUX_BLK_TYPES_H
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#include <linux/types.h>
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#include <linux/bvec.h>
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struct bio_set;
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struct bio;
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struct bio_integrity_payload;
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struct page;
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struct block_device;
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struct io_context;
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struct cgroup_subsys_state;
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typedef void (bio_end_io_t) (struct bio *);
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#ifdef CONFIG_BLOCK
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/*
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* main unit of I/O for the block layer and lower layers (ie drivers and
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* stacking drivers)
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*/
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struct bio {
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struct bio *bi_next; /* request queue link */
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struct block_device *bi_bdev;
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int bi_error;
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unsigned int bi_opf; /* bottom bits req flags,
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* top bits REQ_OP. Use
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* accessors.
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*/
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unsigned short bi_flags; /* status, command, etc */
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unsigned short bi_ioprio;
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struct bvec_iter bi_iter;
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/* Number of segments in this BIO after
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* physical address coalescing is performed.
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*/
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unsigned int bi_phys_segments;
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/*
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* To keep track of the max segment size, we account for the
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* sizes of the first and last mergeable segments in this bio.
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*/
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unsigned int bi_seg_front_size;
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unsigned int bi_seg_back_size;
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atomic_t __bi_remaining;
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bio_end_io_t *bi_end_io;
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void *bi_private;
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#ifdef CONFIG_BLK_CGROUP
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/*
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* Optional ioc and css associated with this bio. Put on bio
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* release. Read comment on top of bio_associate_current().
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*/
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struct io_context *bi_ioc;
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struct cgroup_subsys_state *bi_css;
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#endif
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union {
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#if defined(CONFIG_BLK_DEV_INTEGRITY)
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struct bio_integrity_payload *bi_integrity; /* data integrity */
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#endif
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};
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unsigned short bi_vcnt; /* how many bio_vec's */
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/*
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* Everything starting with bi_max_vecs will be preserved by bio_reset()
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*/
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unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
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atomic_t __bi_cnt; /* pin count */
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struct bio_vec *bi_io_vec; /* the actual vec list */
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struct bio_set *bi_pool;
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/*
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* We can inline a number of vecs at the end of the bio, to avoid
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* double allocations for a small number of bio_vecs. This member
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* MUST obviously be kept at the very end of the bio.
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*/
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struct bio_vec bi_inline_vecs[0];
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};
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#define BIO_OP_SHIFT (8 * FIELD_SIZEOF(struct bio, bi_opf) - REQ_OP_BITS)
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#define bio_flags(bio) ((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1))
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#define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT)
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#define bio_set_op_attrs(bio, op, op_flags) do { \
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if (__builtin_constant_p(op)) \
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BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS)); \
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else \
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WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS)); \
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if (__builtin_constant_p(op_flags)) \
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BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \
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else \
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WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \
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(bio)->bi_opf = bio_flags(bio); \
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(bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT); \
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(bio)->bi_opf |= (op_flags); \
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} while (0)
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#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
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/*
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* bio flags
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*/
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#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
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#define BIO_CLONED 2 /* doesn't own data */
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#define BIO_BOUNCED 3 /* bio is a bounce bio */
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#define BIO_USER_MAPPED 4 /* contains user pages */
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#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
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#define BIO_QUIET 6 /* Make BIO Quiet */
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#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
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#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
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/*
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* Flags starting here get preserved by bio_reset() - this includes
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* BVEC_POOL_IDX()
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*/
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#define BIO_RESET_BITS 10
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/*
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* We support 6 different bvec pools, the last one is magic in that it
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* is backed by a mempool.
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*/
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#define BVEC_POOL_NR 6
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#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
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/*
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* Top 4 bits of bio flags indicate the pool the bvecs came from. We add
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* 1 to the actual index so that 0 indicates that there are no bvecs to be
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* freed.
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*/
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#define BVEC_POOL_BITS (4)
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#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
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#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
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#endif /* CONFIG_BLOCK */
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/*
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* Request flags. For use in the cmd_flags field of struct request, and in
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* bi_opf of struct bio. Note that some flags are only valid in either one.
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*/
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enum rq_flag_bits {
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/* common flags */
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__REQ_FAILFAST_DEV, /* no driver retries of device errors */
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__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
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__REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
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__REQ_SYNC, /* request is sync (sync write or read) */
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__REQ_META, /* metadata io request */
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__REQ_PRIO, /* boost priority in cfq */
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__REQ_NOIDLE, /* don't anticipate more IO after this one */
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__REQ_INTEGRITY, /* I/O includes block integrity payload */
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__REQ_FUA, /* forced unit access */
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__REQ_PREFLUSH, /* request for cache flush */
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/* bio only flags */
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__REQ_RAHEAD, /* read ahead, can fail anytime */
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__REQ_THROTTLED, /* This bio has already been subjected to
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* throttling rules. Don't do it again. */
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/* request only flags */
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__REQ_SORTED, /* elevator knows about this request */
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__REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
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__REQ_NOMERGE, /* don't touch this for merging */
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__REQ_STARTED, /* drive already may have started this one */
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__REQ_DONTPREP, /* don't call prep for this one */
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__REQ_QUEUED, /* uses queueing */
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__REQ_ELVPRIV, /* elevator private data attached */
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__REQ_FAILED, /* set if the request failed */
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__REQ_QUIET, /* don't worry about errors */
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__REQ_PREEMPT, /* set for "ide_preempt" requests and also
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for requests for which the SCSI "quiesce"
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state must be ignored. */
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__REQ_ALLOCED, /* request came from our alloc pool */
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__REQ_COPY_USER, /* contains copies of user pages */
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__REQ_FLUSH_SEQ, /* request for flush sequence */
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__REQ_IO_STAT, /* account I/O stat */
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__REQ_MIXED_MERGE, /* merge of different types, fail separately */
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__REQ_PM, /* runtime pm request */
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__REQ_HASHED, /* on IO scheduler merge hash */
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__REQ_MQ_INFLIGHT, /* track inflight for MQ */
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__REQ_NR_BITS, /* stops here */
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};
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#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
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#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
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#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
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#define REQ_SYNC (1ULL << __REQ_SYNC)
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#define REQ_META (1ULL << __REQ_META)
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#define REQ_PRIO (1ULL << __REQ_PRIO)
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#define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
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#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
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#define REQ_FAILFAST_MASK \
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(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
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#define REQ_COMMON_MASK \
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(REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \
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REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE)
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#define REQ_CLONE_MASK REQ_COMMON_MASK
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/* This mask is used for both bio and request merge checking */
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#define REQ_NOMERGE_FLAGS \
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(REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_PREFLUSH | REQ_FUA | REQ_FLUSH_SEQ)
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#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
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#define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
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#define REQ_SORTED (1ULL << __REQ_SORTED)
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#define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
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#define REQ_FUA (1ULL << __REQ_FUA)
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#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
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#define REQ_STARTED (1ULL << __REQ_STARTED)
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#define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
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#define REQ_QUEUED (1ULL << __REQ_QUEUED)
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#define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
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#define REQ_FAILED (1ULL << __REQ_FAILED)
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#define REQ_QUIET (1ULL << __REQ_QUIET)
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#define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
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#define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
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#define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
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#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
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#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
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#define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
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#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
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#define REQ_PM (1ULL << __REQ_PM)
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#define REQ_HASHED (1ULL << __REQ_HASHED)
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#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)
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enum req_op {
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REQ_OP_READ,
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REQ_OP_WRITE,
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REQ_OP_DISCARD, /* request to discard sectors */
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REQ_OP_SECURE_ERASE, /* request to securely erase sectors */
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REQ_OP_WRITE_SAME, /* write same block many times */
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REQ_OP_FLUSH, /* request for cache flush */
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};
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#define REQ_OP_BITS 3
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typedef unsigned int blk_qc_t;
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#define BLK_QC_T_NONE -1U
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#define BLK_QC_T_SHIFT 16
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static inline bool blk_qc_t_valid(blk_qc_t cookie)
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{
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return cookie != BLK_QC_T_NONE;
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}
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static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
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{
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return tag | (queue_num << BLK_QC_T_SHIFT);
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}
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static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
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{
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return cookie >> BLK_QC_T_SHIFT;
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}
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static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
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{
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return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
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}
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#endif /* __LINUX_BLK_TYPES_H */
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