1 /*- 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 */ 9 10 #include <sys/cdefs.h> 11 __FBSDID("$FreeBSD$"); 12 13 #include "opt_geom.h" 14 15 #include <sys/param.h> 16 #include <sys/systm.h> 17 #include <sys/bio.h> 18 #include <sys/conf.h> 19 #include <sys/disk.h> 20 #include <geom/geom_disk.h> 21 22 /*- 23 * Disk error is the preface to plaintive error messages 24 * about failing disk transfers. It prints messages of the form 25 * "hp0g: BLABLABLA cmd=read fsbn 12345 of 12344-12347" 26 * blkdone should be -1 if the position of the error is unknown. 27 * The message is printed with printf. 28 */ 29 void 30 disk_err(struct bio *bp, const char *what, int blkdone, int nl) 31 { 32 daddr_t sn; 33 34 if (bp->bio_dev != NULL) 35 printf("%s: %s ", devtoname(bp->bio_dev), what); 36 else if (bp->bio_disk != NULL) 37 printf("%s%d: %s ", 38 bp->bio_disk->d_name, bp->bio_disk->d_unit, what); 39 else 40 printf("disk??: %s ", what); 41 switch(bp->bio_cmd) { 42 case BIO_READ: printf("cmd=read "); break; 43 case BIO_WRITE: printf("cmd=write "); break; 44 case BIO_DELETE: printf("cmd=delete "); break; 45 case BIO_GETATTR: printf("cmd=getattr "); break; 46 default: printf("cmd=%x ", bp->bio_cmd); break; 47 } 48 sn = bp->bio_pblkno; 49 if (bp->bio_bcount <= DEV_BSIZE) { 50 printf("fsbn %jd%s", (intmax_t)sn, nl ? "\n" : ""); 51 return; 52 } 53 if (blkdone >= 0) { 54 sn += blkdone; 55 printf("fsbn %jd of ", (intmax_t)sn); 56 } 57 printf("%jd-%jd", (intmax_t)bp->bio_pblkno, 58 (intmax_t)(bp->bio_pblkno + (bp->bio_bcount - 1) / DEV_BSIZE)); 59 if (nl) 60 printf("\n"); 61 } 62 63 /* 64 * BIO queue implementation 65 */ 66 67 void 68 bioq_init(struct bio_queue_head *head) 69 { 70 TAILQ_INIT(&head->queue); 71 head->last_offset = 0; 72 head->insert_point = NULL; 73 } 74 75 void 76 bioq_remove(struct bio_queue_head *head, struct bio *bp) 77 { 78 if (bp == head->insert_point) { 79 head->last_offset = bp->bio_offset; 80 head->insert_point = TAILQ_NEXT(bp, bio_queue); 81 if (head->insert_point == NULL) { 82 head->last_offset = 0; 83 head->insert_point = TAILQ_FIRST(&head->queue); 84 } 85 } 86 TAILQ_REMOVE(&head->queue, bp, bio_queue); 87 } 88 89 void 90 bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error) 91 { 92 struct bio *bp; 93 94 while ((bp = bioq_takefirst(head)) != NULL) 95 biofinish(bp, stp, error); 96 } 97 98 void 99 bioq_insert_head(struct bio_queue_head *head, struct bio *bp) 100 { 101 102 if (TAILQ_FIRST(&head->queue) == NULL) 103 head->insert_point = bp; 104 TAILQ_INSERT_HEAD(&head->queue, bp, bio_queue); 105 } 106 107 void 108 bioq_insert_tail(struct bio_queue_head *head, struct bio *bp) 109 { 110 111 if (TAILQ_FIRST(&head->queue) == NULL) 112 head->insert_point = bp; 113 TAILQ_INSERT_TAIL(&head->queue, bp, bio_queue); 114 } 115 116 struct bio * 117 bioq_first(struct bio_queue_head *head) 118 { 119 120 return (TAILQ_FIRST(&head->queue)); 121 } 122 123 struct bio * 124 bioq_takefirst(struct bio_queue_head *head) 125 { 126 struct bio *bp; 127 128 bp = TAILQ_FIRST(&head->queue); 129 if (bp != NULL) 130 bioq_remove(head, bp); 131 return (bp); 132 } 133 134 /* 135 * Seek sort for disks. 136 * 137 * The disksort algorithm sorts all requests in a single queue while keeping 138 * track of the current position of the disk with insert_point and 139 * last_offset. last_offset is the offset of the last block sent to disk, or 140 * 0 once we reach the end. insert_point points to the first buf after 141 * last_offset, and is used to slightly speed up insertions. Blocks are 142 * always sorted in ascending order and the queue always restarts at 0. 143 * This implements the one-way scan which optimizes disk seek times. 144 */ 145 void 146 bioq_disksort(bioq, bp) 147 struct bio_queue_head *bioq; 148 struct bio *bp; 149 { 150 struct bio *bq; 151 struct bio *bn; 152 153 /* 154 * If the queue is empty then it's easy. 155 */ 156 if (bioq_first(bioq) == NULL) { 157 bioq_insert_tail(bioq, bp); 158 return; 159 } 160 /* 161 * Optimize for sequential I/O by seeing if we go at the tail. 162 */ 163 bq = TAILQ_LAST(&bioq->queue, bio_queue); 164 if (bp->bio_offset > bq->bio_offset) { 165 TAILQ_INSERT_AFTER(&bioq->queue, bq, bp, bio_queue); 166 return; 167 } 168 /* 169 * Pick our scan start based on the last request. A poor man's 170 * binary search. 171 */ 172 if (bp->bio_offset >= bioq->last_offset) { 173 bq = bioq->insert_point; 174 /* 175 * If we're before the next bio and after the last offset, 176 * update insert_point; 177 */ 178 if (bp->bio_offset < bq->bio_offset) { 179 bioq->insert_point = bp; 180 TAILQ_INSERT_BEFORE(bq, bp, bio_queue); 181 return; 182 } 183 } else 184 bq = TAILQ_FIRST(&bioq->queue); 185 if (bp->bio_offset < bq->bio_offset) { 186 TAILQ_INSERT_BEFORE(bq, bp, bio_queue); 187 return; 188 } 189 /* Insertion sort */ 190 while ((bn = TAILQ_NEXT(bq, bio_queue)) != NULL) { 191 if (bp->bio_offset < bn->bio_offset) 192 break; 193 bq = bn; 194 } 195 TAILQ_INSERT_AFTER(&bioq->queue, bq, bp, bio_queue); 196 } 197