Add bioq_takefirst().
If the bioq is empty, NULL is returned. Otherwise the front element is removed and returned. This can simplify locking in many drivers from: lock() bp = bioq_first(bq); if (bp == NULL) { unlock() return } bioq_remove(bp, bq) unlock to: lock() bp = bioq_takefirst(bq); unlock() if (bp == NULL) return;
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0ce70eb477
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svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=134038
@ -94,13 +94,8 @@ bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error)
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{
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struct bio *bp;
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for (;;) {
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bp = bioq_first(head);
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if (bp == NULL)
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break;
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bioq_remove(head, bp);
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while ((bp = bioq_takefirst(head)) != NULL)
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biofinish(bp, stp, error);
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}
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}
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void
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@ -117,6 +112,16 @@ bioq_first(struct bio_queue_head *head)
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return (TAILQ_FIRST(&head->queue));
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}
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struct bio *
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bioq_takefirst(struct bio_queue_head *head)
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{
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struct bio *bp;
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bp = TAILQ_FIRST(&head->queue);
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if (bp != NULL)
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bioq_remove(head, bp);
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return (bp);
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}
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/*
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* Seek sort for disks.
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@ -88,6 +88,7 @@ struct bio {
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#define BIO_WRITE 0x02
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#define BIO_DELETE 0x04
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#define BIO_GETATTR 0x08
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#define BIO_CMD0 0x20 /* Available for local hacks */
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#define BIO_CMD1 0x40 /* Available for local hacks */
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#define BIO_CMD2 0x80 /* Available for local hacks */
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@ -113,6 +114,7 @@ int biowait(struct bio *bp, const char *wchan);
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void bioq_disksort(struct bio_queue_head *ap, struct bio *bp);
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struct bio *bioq_first(struct bio_queue_head *head);
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struct bio *bioq_takefirst(struct bio_queue_head *head);
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void bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error);
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void bioq_init(struct bio_queue_head *head);
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void bioq_insert_tail(struct bio_queue_head *head, struct bio *bp);
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