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![Jens Axboe](/assets/img/avatar_default.png)
With the plugging now being explicitly controlled by the submitter, callers need not pass down unplugging hints to the block layer. If they want to unplug, it's because they manually plugged on their own - in which case, they should just unplug at will. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
197 lines
6.6 KiB
C
197 lines
6.6 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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#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_MAPPED_INTEGRITY 12/* integrity metadata has been remapped */
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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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#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_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_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_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_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_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, /* request for cache flush */
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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_SECURE, /* secure discard (used with __REQ_DISCARD) */
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__REQ_ON_PLUG, /* on plug list */
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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_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_SYNC | REQ_META | REQ_DISCARD | \
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REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
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#define REQ_CLONE_MASK REQ_COMMON_MASK
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#define REQ_RAHEAD (1 << __REQ_RAHEAD)
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#define REQ_THROTTLED (1 << __REQ_THROTTLED)
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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_ALLOCED (1 << __REQ_ALLOCED)
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#define REQ_COPY_USER (1 << __REQ_COPY_USER)
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#define REQ_FLUSH (1 << __REQ_FLUSH)
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#define REQ_FLUSH_SEQ (1 << __REQ_FLUSH_SEQ)
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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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#define REQ_SECURE (1 << __REQ_SECURE)
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#define REQ_ON_PLUG (1 << __REQ_ON_PLUG)
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#endif /* __LINUX_BLK_TYPES_H */
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