194 lines
6.4 KiB
C
194 lines
6.4 KiB
C
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/*
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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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#ifdef CONFIG_BLOCK
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#include <linux/types.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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typedef void (bio_end_io_t) (struct bio *, int);
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typedef void (bio_destructor_t) (struct bio *);
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/*
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* was unsigned short, but we might as well be ready for > 64kB I/O pages
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*/
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struct bio_vec {
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struct page *bv_page;
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unsigned int bv_len;
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unsigned int bv_offset;
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};
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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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sector_t bi_sector; /* device address in 512 byte
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sectors */
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struct bio *bi_next; /* request queue link */
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struct block_device *bi_bdev;
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unsigned long bi_flags; /* status, command, etc */
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unsigned long bi_rw; /* bottom bits READ/WRITE,
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* top bits priority
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*/
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unsigned short bi_vcnt; /* how many bio_vec's */
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unsigned short bi_idx; /* current index into bvl_vec */
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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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unsigned int bi_size; /* residual I/O count */
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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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unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
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unsigned int bi_comp_cpu; /* completion CPU */
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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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bio_end_io_t *bi_end_io;
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void *bi_private;
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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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bio_destructor_t *bi_destructor; /* destructor */
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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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/*
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* bio flags
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*/
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#define BIO_UPTODATE 0 /* ok after I/O completion */
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#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
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#define BIO_EOF 2 /* out-out-bounds error */
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#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
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#define BIO_CLONED 4 /* doesn't own data */
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#define BIO_BOUNCED 5 /* bio is a bounce bio */
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#define BIO_USER_MAPPED 6 /* contains user pages */
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#define BIO_EOPNOTSUPP 7 /* not supported */
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#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
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#define BIO_NULL_MAPPED 9 /* contains invalid user pages */
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#define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
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#define BIO_QUIET 11 /* Make BIO Quiet */
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#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
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/*
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* top 4 bits of bio flags indicate the pool this bio came from
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*/
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#define BIO_POOL_BITS (4)
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#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
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#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
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#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
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#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
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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_rw 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_WRITE, /* not set, read. set, write */
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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_HARDBARRIER, /* may not be passed by drive either */
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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_DISCARD, /* request to discard sectors */
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__REQ_NOIDLE, /* don't anticipate more IO after this one */
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/* bio only flags */
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__REQ_UNPLUG, /* unplug the immediately after submission */
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__REQ_RAHEAD, /* read ahead, can fail anytime */
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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_FUA, /* forced unit access */
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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 */
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__REQ_ORDERED_COLOR, /* is before or after barrier */
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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_INTEGRITY, /* integrity metadata has been remapped */
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__REQ_FLUSH, /* request for cache flush */
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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_NR_BITS, /* stops here */
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};
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#define REQ_WRITE (1 << __REQ_WRITE)
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#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
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#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
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#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
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#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
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#define REQ_SYNC (1 << __REQ_SYNC)
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#define REQ_META (1 << __REQ_META)
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#define REQ_DISCARD (1 << __REQ_DISCARD)
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#define REQ_NOIDLE (1 << __REQ_NOIDLE)
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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_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
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REQ_META| REQ_DISCARD | REQ_NOIDLE)
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#define REQ_UNPLUG (1 << __REQ_UNPLUG)
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#define REQ_RAHEAD (1 << __REQ_RAHEAD)
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#define REQ_SORTED (1 << __REQ_SORTED)
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#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
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#define REQ_FUA (1 << __REQ_FUA)
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#define REQ_NOMERGE (1 << __REQ_NOMERGE)
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#define REQ_STARTED (1 << __REQ_STARTED)
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#define REQ_DONTPREP (1 << __REQ_DONTPREP)
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#define REQ_QUEUED (1 << __REQ_QUEUED)
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#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
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#define REQ_FAILED (1 << __REQ_FAILED)
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#define REQ_QUIET (1 << __REQ_QUIET)
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#define REQ_PREEMPT (1 << __REQ_PREEMPT)
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#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
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#define REQ_ALLOCED (1 << __REQ_ALLOCED)
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#define REQ_COPY_USER (1 << __REQ_COPY_USER)
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#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
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#define REQ_FLUSH (1 << __REQ_FLUSH)
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#define REQ_IO_STAT (1 << __REQ_IO_STAT)
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#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
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#endif /* CONFIG_BLOCK */
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#endif /* __LINUX_BLK_TYPES_H */
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