block: use the same failfast bits for bio and request
bio and request use the same set of failfast bits. This patch makes the following changes to simplify things. * enumify BIO_RW* bits and reorder bits such that BIOS_RW_FAILFAST_* bits coincide with __REQ_FAILFAST_* bits. * The above pushes BIO_RW_AHEAD out of sync with __REQ_FAILFAST_DEV but the matching is useless anyway. init_request_from_bio() is responsible for setting FAILFAST bits on FS requests and non-FS requests never use BIO_RW_AHEAD. Drop the code and comment from blk_rq_bio_prep(). * Define REQ_FAILFAST_MASK which is OR of all FAILFAST bits and simplify FAILFAST flags handling in init_request_from_bio(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Tejun Heo
Jens Axboe
parent
0d03d59d9b
commit
a82afdfcb8
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@ -1111,17 +1111,13 @@ void init_request_from_bio(struct request *req, struct bio *bio)
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req->cmd_type = REQ_TYPE_FS;
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/*
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* inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
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* Inherit FAILFAST from bio (for read-ahead, and explicit
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* FAILFAST). FAILFAST flags are identical for req and bio.
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*/
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if (bio_rw_ahead(bio))
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req->cmd_flags |= (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
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REQ_FAILFAST_DRIVER);
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if (bio_failfast_dev(bio))
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req->cmd_flags |= REQ_FAILFAST_DEV;
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if (bio_failfast_transport(bio))
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req->cmd_flags |= REQ_FAILFAST_TRANSPORT;
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if (bio_failfast_driver(bio))
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req->cmd_flags |= REQ_FAILFAST_DRIVER;
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req->cmd_flags |= REQ_FAILFAST_MASK;
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else
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req->cmd_flags |= bio->bi_rw & REQ_FAILFAST_MASK;
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if (unlikely(bio_discard(bio))) {
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req->cmd_flags |= REQ_DISCARD;
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@ -2239,9 +2235,8 @@ EXPORT_SYMBOL(__blk_end_request_cur);
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void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
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struct bio *bio)
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{
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/* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
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we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
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rq->cmd_flags |= (bio->bi_rw & 3);
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/* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw */
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rq->cmd_flags |= bio->bi_rw & REQ_RW;
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if (bio_has_data(bio)) {
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rq->nr_phys_segments = bio_phys_segments(q, bio);
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@ -142,37 +142,40 @@ struct bio {
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*
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* bit 0 -- data direction
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* If not set, bio is a read from device. If set, it's a write to device.
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* bit 1 -- rw-ahead when set
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* bit 2 -- barrier
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* bit 1 -- fail fast device errors
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* bit 2 -- fail fast transport errors
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* bit 3 -- fail fast driver errors
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* bit 4 -- rw-ahead when set
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* bit 5 -- barrier
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* Insert a serialization point in the IO queue, forcing previously
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* submitted IO to be completed before this one is issued.
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* bit 3 -- synchronous I/O hint.
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* bit 4 -- Unplug the device immediately after submitting this bio.
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* bit 5 -- metadata request
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* bit 6 -- synchronous I/O hint.
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* bit 7 -- Unplug the device immediately after submitting this bio.
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* bit 8 -- metadata request
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* Used for tracing to differentiate metadata and data IO. May also
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* get some preferential treatment in the IO scheduler
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* bit 6 -- discard sectors
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* bit 9 -- discard sectors
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* Informs the lower level device that this range of sectors is no longer
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* used by the file system and may thus be freed by the device. Used
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* for flash based storage.
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* bit 7 -- fail fast device errors
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* bit 8 -- fail fast transport errors
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* bit 9 -- fail fast driver errors
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* Don't want driver retries for any fast fail whatever the reason.
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* bit 10 -- Tell the IO scheduler not to wait for more requests after this
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one has been submitted, even if it is a SYNC request.
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*/
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#define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
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#define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
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#define BIO_RW_BARRIER 2
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#define BIO_RW_SYNCIO 3
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#define BIO_RW_UNPLUG 4
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#define BIO_RW_META 5
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#define BIO_RW_DISCARD 6
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#define BIO_RW_FAILFAST_DEV 7
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#define BIO_RW_FAILFAST_TRANSPORT 8
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#define BIO_RW_FAILFAST_DRIVER 9
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#define BIO_RW_NOIDLE 10
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enum bio_rw_flags {
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BIO_RW,
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BIO_RW_FAILFAST_DEV,
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BIO_RW_FAILFAST_TRANSPORT,
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BIO_RW_FAILFAST_DRIVER,
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/* above flags must match REQ_* */
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BIO_RW_AHEAD,
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BIO_RW_BARRIER,
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BIO_RW_SYNCIO,
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BIO_RW_UNPLUG,
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BIO_RW_META,
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BIO_RW_DISCARD,
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BIO_RW_NOIDLE,
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};
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#define bio_rw_flagged(bio, flag) ((bio)->bi_rw & (1 << (flag)))
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@ -93,6 +93,7 @@ enum rq_flag_bits {
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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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/* above flags must match BIO_RW_* */
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__REQ_DISCARD, /* request to discard sectors */
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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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@ -143,6 +144,9 @@ enum rq_flag_bits {
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#define REQ_NOIDLE (1 << __REQ_NOIDLE)
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#define REQ_IO_STAT (1 << __REQ_IO_STAT)
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#define REQ_FAILFAST_MASK (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | \
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REQ_FAILFAST_DRIVER)
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#define BLK_MAX_CDB 16
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/*
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