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 * $FreeBSD: src/sys/dev/md/md.c,v 1.8.2.2 2002/08/19 17:43:34 jdp Exp $ 10 * $DragonFly: src/sys/dev/disk/md/md.c,v 1.10 2006/03/24 18:35:32 dillon Exp $ 11 * 12 */ 13 14 #include "opt_mfs.h" /* We have adopted some tasks from MFS */ 15 #include "opt_md.h" /* We have adopted some tasks from MFS */ 16 17 #include <sys/param.h> 18 #include <sys/systm.h> 19 #include <sys/buf.h> 20 #include <sys/conf.h> 21 #include <sys/devicestat.h> 22 #include <sys/disk.h> 23 #include <sys/kernel.h> 24 #include <sys/malloc.h> 25 #include <sys/sysctl.h> 26 #include <sys/linker.h> 27 #include <sys/proc.h> 28 #include <sys/buf2.h> 29 #include <sys/thread2.h> 30 31 #ifndef MD_NSECT 32 #define MD_NSECT (10000 * 2) 33 #endif 34 35 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk"); 36 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors"); 37 38 static int md_debug; 39 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, ""); 40 41 #if defined(MFS_ROOT) && !defined(MD_ROOT) 42 #define MD_ROOT MFS_ROOT 43 #warning "option MFS_ROOT has been superceeded by MD_ROOT" 44 #endif 45 46 #if defined(MFS_ROOT_SIZE) && !defined(MD_ROOT_SIZE) 47 #define MD_ROOT_SIZE MFS_ROOT_SIZE 48 #warning "option MFS_ROOT_SIZE has been superceeded by MD_ROOT_SIZE" 49 #endif 50 51 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE) 52 /* Image gets put here: */ 53 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here"; 54 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here"; 55 #endif 56 57 static int mdrootready; 58 59 static void mdcreate_malloc(void); 60 61 #define CDEV_MAJOR 95 62 63 static d_strategy_t mdstrategy; 64 static d_strategy_t mdstrategy_preload; 65 static d_strategy_t mdstrategy_malloc; 66 static d_open_t mdopen; 67 static d_ioctl_t mdioctl; 68 69 static struct cdevsw md_cdevsw = { 70 /* name */ "md", 71 /* maj */ CDEV_MAJOR, 72 /* flags */ D_DISK | D_CANFREE | D_MEMDISK, 73 /* port */ NULL, 74 /* clone */ NULL, 75 76 /* open */ mdopen, 77 /* close */ nullclose, 78 /* read */ physread, 79 /* write */ physwrite, 80 /* ioctl */ mdioctl, 81 /* poll */ nopoll, 82 /* mmap */ nommap, 83 /* strategy */ mdstrategy, 84 /* dump */ nodump, 85 /* psize */ nopsize, 86 }; 87 88 struct md_s { 89 int unit; 90 struct devstat stats; 91 struct bio_queue_head bio_queue; 92 struct disk disk; 93 dev_t dev; 94 int busy; 95 enum {MD_MALLOC, MD_PRELOAD} type; 96 unsigned nsect; 97 98 /* MD_MALLOC related fields */ 99 unsigned nsecp; 100 u_char **secp; 101 102 /* MD_PRELOAD related fields */ 103 u_char *pl_ptr; 104 unsigned pl_len; 105 }; 106 107 static int mdunits; 108 109 static int 110 mdopen(dev_t dev, int flag, int fmt, struct thread *td) 111 { 112 struct md_s *sc; 113 struct disklabel *dl; 114 115 if (md_debug) 116 printf("mdopen(%s %x %x %p)\n", 117 devtoname(dev), flag, fmt, td); 118 119 sc = dev->si_drv1; 120 if (sc->unit + 1 == mdunits) 121 mdcreate_malloc(); 122 123 dl = &sc->disk.d_label; 124 bzero(dl, sizeof(*dl)); 125 dl->d_secsize = DEV_BSIZE; 126 dl->d_nsectors = 1024; 127 dl->d_ntracks = 1; 128 dl->d_secpercyl = dl->d_nsectors * dl->d_ntracks; 129 dl->d_secperunit = sc->nsect; 130 dl->d_ncylinders = dl->d_secperunit / dl->d_secpercyl; 131 return (0); 132 } 133 134 static int 135 mdioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct thread *td) 136 { 137 138 if (md_debug) 139 printf("mdioctl(%s %lx %p %x %p)\n", 140 devtoname(dev), cmd, addr, flags, td); 141 142 return (ENOIOCTL); 143 } 144 145 static void 146 mdstrategy(dev_t dev, struct bio *bio) 147 { 148 struct buf *bp = bio->bio_buf; 149 struct md_s *sc; 150 151 if (md_debug > 1) { 152 printf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n", 153 bp, devtoname(dev), bp->b_flags, bio->bio_offset, 154 bp->b_bcount, bp->b_data); 155 } 156 bio->bio_driver_info = dev; 157 sc = dev->si_drv1; 158 if (sc->type == MD_MALLOC) { 159 mdstrategy_malloc(dev, bio); 160 } else { 161 mdstrategy_preload(dev, bio); 162 } 163 } 164 165 166 static void 167 mdstrategy_malloc(dev_t dev, struct bio *bio) 168 { 169 struct buf *bp = bio->bio_buf; 170 unsigned secno, nsec, secval, uc; 171 u_char *secp, **secpp, *dst; 172 devstat_trans_flags dop; 173 struct md_s *sc; 174 int i; 175 176 if (md_debug > 1) 177 printf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n", 178 bp, devtoname(dev), bp->b_flags, bio->bio_offset, 179 bp->b_bcount, bp->b_data); 180 181 sc = dev->si_drv1; 182 183 crit_enter(); 184 185 bioqdisksort(&sc->bio_queue, bio); 186 187 if (sc->busy) { 188 crit_exit(); 189 return; 190 } 191 192 sc->busy++; 193 194 while (1) { 195 bio = bioq_first(&sc->bio_queue); 196 if (bp) 197 bioq_remove(&sc->bio_queue, bio); 198 crit_exit(); 199 if (bio == NULL) 200 break; 201 202 devstat_start_transaction(&sc->stats); 203 204 if (bp->b_flags & B_FREEBUF) 205 dop = DEVSTAT_NO_DATA; 206 else if (bp->b_flags & B_READ) 207 dop = DEVSTAT_READ; 208 else 209 dop = DEVSTAT_WRITE; 210 211 nsec = bp->b_bcount >> DEV_BSHIFT; 212 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT); 213 dst = bp->b_data; 214 while (nsec--) { 215 if (secno < sc->nsecp) { 216 secpp = &sc->secp[secno]; 217 if ((u_int)*secpp > 255) { 218 secp = *secpp; 219 secval = 0; 220 } else { 221 secp = 0; 222 secval = (u_int) *secpp; 223 } 224 } else { 225 secpp = 0; 226 secp = 0; 227 secval = 0; 228 } 229 if (md_debug > 2) 230 printf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval); 231 232 if (bp->b_flags & B_FREEBUF) { 233 if (secpp) { 234 if (secp) 235 FREE(secp, M_MDSECT); 236 *secpp = 0; 237 } 238 } else if (bp->b_flags & B_READ) { 239 if (secp) { 240 bcopy(secp, dst, DEV_BSIZE); 241 } else if (secval) { 242 for (i = 0; i < DEV_BSIZE; i++) 243 dst[i] = secval; 244 } else { 245 bzero(dst, DEV_BSIZE); 246 } 247 } else { 248 uc = dst[0]; 249 for (i = 1; i < DEV_BSIZE; i++) 250 if (dst[i] != uc) 251 break; 252 if (i == DEV_BSIZE && !uc) { 253 if (secp) 254 FREE(secp, M_MDSECT); 255 if (secpp) 256 *secpp = (u_char *)uc; 257 } else { 258 if (!secpp) { 259 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK); 260 bzero(secpp, (secno + nsec + 1) * sizeof(u_char *)); 261 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 262 FREE(sc->secp, M_MD); 263 sc->secp = secpp; 264 sc->nsecp = secno + nsec + 1; 265 secpp = &sc->secp[secno]; 266 } 267 if (i == DEV_BSIZE) { 268 if (secp) 269 FREE(secp, M_MDSECT); 270 *secpp = (u_char *)uc; 271 } else { 272 if (!secp) 273 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 274 bcopy(dst, secp, DEV_BSIZE); 275 276 *secpp = secp; 277 } 278 } 279 } 280 secno++; 281 dst += DEV_BSIZE; 282 } 283 bp->b_resid = 0; 284 devstat_end_transaction_buf(&sc->stats, bp); 285 biodone(bio); 286 crit_enter(); 287 } 288 sc->busy = 0; 289 } 290 291 292 static void 293 mdstrategy_preload(dev_t dev, struct bio *bio) 294 { 295 struct buf *bp = bio->bio_buf; 296 devstat_trans_flags dop; 297 struct md_s *sc; 298 299 if (md_debug > 1) 300 printf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n", 301 bp, devtoname(dev), bp->b_flags, bio->bio_offset, 302 bp->b_bcount, bp->b_data); 303 304 sc = dev->si_drv1; 305 306 crit_enter(); 307 308 bioqdisksort(&sc->bio_queue, bio); 309 310 if (sc->busy) { 311 crit_exit(); 312 return; 313 } 314 315 sc->busy++; 316 317 while (1) { 318 bio = bioq_first(&sc->bio_queue); 319 if (bio) 320 bioq_remove(&sc->bio_queue, bio); 321 crit_exit(); 322 if (bio == NULL) 323 break; 324 325 devstat_start_transaction(&sc->stats); 326 327 if (bp->b_flags & B_FREEBUF) { 328 dop = DEVSTAT_NO_DATA; 329 } else if (bp->b_flags & B_READ) { 330 dop = DEVSTAT_READ; 331 bcopy(sc->pl_ptr + bio->bio_offset, 332 bp->b_data, bp->b_bcount); 333 } else { 334 dop = DEVSTAT_WRITE; 335 bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset, 336 bp->b_bcount); 337 } 338 bp->b_resid = 0; 339 devstat_end_transaction_buf(&sc->stats, bp); 340 biodone(bio); 341 crit_enter(); 342 } 343 sc->busy = 0; 344 } 345 346 static struct md_s * 347 mdcreate(void) 348 { 349 struct md_s *sc; 350 351 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK); 352 bzero(sc, sizeof(*sc)); 353 sc->unit = mdunits++; 354 bioq_init(&sc->bio_queue); 355 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 356 DEVSTAT_NO_ORDERED_TAGS, 357 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 358 DEVSTAT_PRIORITY_OTHER); 359 sc->dev = disk_create(sc->unit, &sc->disk, 0, &md_cdevsw); 360 sc->dev->si_drv1 = sc; 361 return (sc); 362 } 363 364 static void 365 mdcreate_preload(u_char *image, unsigned length) 366 { 367 struct md_s *sc; 368 369 sc = mdcreate(); 370 sc->type = MD_PRELOAD; 371 sc->nsect = length / DEV_BSIZE; 372 sc->pl_ptr = image; 373 sc->pl_len = length; 374 375 if (sc->unit == 0) 376 mdrootready = 1; 377 } 378 379 static void 380 mdcreate_malloc(void) 381 { 382 struct md_s *sc; 383 384 sc = mdcreate(); 385 sc->type = MD_MALLOC; 386 387 sc->nsect = MD_NSECT; /* for now */ 388 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK); 389 bzero(sc->secp, sizeof(u_char *)); 390 sc->nsecp = 1; 391 printf("md%d: Malloc disk\n", sc->unit); 392 } 393 394 static void 395 md_drvinit(void *unused) 396 { 397 398 caddr_t mod; 399 caddr_t c; 400 u_char *ptr, *name, *type; 401 unsigned len; 402 403 #ifdef MD_ROOT_SIZE 404 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 405 #endif 406 mod = NULL; 407 while ((mod = preload_search_next_name(mod)) != NULL) { 408 name = (char *)preload_search_info(mod, MODINFO_NAME); 409 type = (char *)preload_search_info(mod, MODINFO_TYPE); 410 if (name == NULL) 411 continue; 412 if (type == NULL) 413 continue; 414 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 415 continue; 416 c = preload_search_info(mod, MODINFO_ADDR); 417 ptr = *(u_char **)c; 418 c = preload_search_info(mod, MODINFO_SIZE); 419 len = *(unsigned *)c; 420 printf("md%d: Preloaded image <%s> %d bytes at %p\n", 421 mdunits, name, len, ptr); 422 mdcreate_preload(ptr, len); 423 } 424 mdcreate_malloc(); 425 } 426 427 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL) 428 429 #ifdef MD_ROOT 430 static void 431 md_takeroot(void *junk) 432 { 433 if (mdrootready) 434 rootdevnames[0] = "ufs:/dev/md0c"; 435 } 436 437 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 438 #endif 439