| 1 | /* $NetBSD: fss.c,v 1.95 2016/07/31 12:17:36 hannken Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2003 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Juergen Hannken-Illjes. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * File system snapshot disk driver. |
| 34 | * |
| 35 | * Block/character interface to the snapshot of a mounted file system. |
| 36 | */ |
| 37 | |
| 38 | #include <sys/cdefs.h> |
| 39 | __KERNEL_RCSID(0, "$NetBSD: fss.c,v 1.95 2016/07/31 12:17:36 hannken Exp $" ); |
| 40 | |
| 41 | #include <sys/param.h> |
| 42 | #include <sys/systm.h> |
| 43 | #include <sys/namei.h> |
| 44 | #include <sys/proc.h> |
| 45 | #include <sys/errno.h> |
| 46 | #include <sys/malloc.h> |
| 47 | #include <sys/buf.h> |
| 48 | #include <sys/ioctl.h> |
| 49 | #include <sys/disklabel.h> |
| 50 | #include <sys/device.h> |
| 51 | #include <sys/disk.h> |
| 52 | #include <sys/stat.h> |
| 53 | #include <sys/mount.h> |
| 54 | #include <sys/vnode.h> |
| 55 | #include <sys/file.h> |
| 56 | #include <sys/uio.h> |
| 57 | #include <sys/conf.h> |
| 58 | #include <sys/kthread.h> |
| 59 | #include <sys/fstrans.h> |
| 60 | #include <sys/vfs_syscalls.h> /* For do_sys_unlink(). */ |
| 61 | |
| 62 | #include <miscfs/specfs/specdev.h> |
| 63 | |
| 64 | #include <dev/fssvar.h> |
| 65 | |
| 66 | #include <uvm/uvm.h> |
| 67 | |
| 68 | #include "ioconf.h" |
| 69 | |
| 70 | dev_type_open(fss_open); |
| 71 | dev_type_close(fss_close); |
| 72 | dev_type_read(fss_read); |
| 73 | dev_type_write(fss_write); |
| 74 | dev_type_ioctl(fss_ioctl); |
| 75 | dev_type_strategy(fss_strategy); |
| 76 | dev_type_dump(fss_dump); |
| 77 | dev_type_size(fss_size); |
| 78 | |
| 79 | static void fss_unmount_hook(struct mount *); |
| 80 | static int fss_copy_on_write(void *, struct buf *, bool); |
| 81 | static inline void fss_error(struct fss_softc *, const char *); |
| 82 | static int fss_create_files(struct fss_softc *, struct fss_set *, |
| 83 | off_t *, struct lwp *); |
| 84 | static int fss_create_snapshot(struct fss_softc *, struct fss_set *, |
| 85 | struct lwp *); |
| 86 | static int fss_delete_snapshot(struct fss_softc *, struct lwp *); |
| 87 | static int fss_softc_alloc(struct fss_softc *); |
| 88 | static void fss_softc_free(struct fss_softc *); |
| 89 | static int fss_read_cluster(struct fss_softc *, u_int32_t); |
| 90 | static void fss_bs_thread(void *); |
| 91 | static int fss_bs_io(struct fss_softc *, fss_io_type, |
| 92 | u_int32_t, off_t, int, void *); |
| 93 | static u_int32_t *fss_bs_indir(struct fss_softc *, u_int32_t); |
| 94 | |
| 95 | static kmutex_t fss_device_lock; /* Protect all units. */ |
| 96 | static int fss_num_attached = 0; /* Number of attached devices. */ |
| 97 | static struct vfs_hooks fss_vfs_hooks = { |
| 98 | .vh_unmount = fss_unmount_hook |
| 99 | }; |
| 100 | |
| 101 | const struct bdevsw fss_bdevsw = { |
| 102 | .d_open = fss_open, |
| 103 | .d_close = fss_close, |
| 104 | .d_strategy = fss_strategy, |
| 105 | .d_ioctl = fss_ioctl, |
| 106 | .d_dump = fss_dump, |
| 107 | .d_psize = fss_size, |
| 108 | .d_discard = nodiscard, |
| 109 | .d_flag = D_DISK | D_MPSAFE |
| 110 | }; |
| 111 | |
| 112 | const struct cdevsw fss_cdevsw = { |
| 113 | .d_open = fss_open, |
| 114 | .d_close = fss_close, |
| 115 | .d_read = fss_read, |
| 116 | .d_write = fss_write, |
| 117 | .d_ioctl = fss_ioctl, |
| 118 | .d_stop = nostop, |
| 119 | .d_tty = notty, |
| 120 | .d_poll = nopoll, |
| 121 | .d_mmap = nommap, |
| 122 | .d_kqfilter = nokqfilter, |
| 123 | .d_discard = nodiscard, |
| 124 | .d_flag = D_DISK | D_MPSAFE |
| 125 | }; |
| 126 | |
| 127 | static int fss_match(device_t, cfdata_t, void *); |
| 128 | static void fss_attach(device_t, device_t, void *); |
| 129 | static int fss_detach(device_t, int); |
| 130 | |
| 131 | CFATTACH_DECL_NEW(fss, sizeof(struct fss_softc), |
| 132 | fss_match, fss_attach, fss_detach, NULL); |
| 133 | extern struct cfdriver fss_cd; |
| 134 | |
| 135 | void |
| 136 | fssattach(int num) |
| 137 | { |
| 138 | |
| 139 | mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); |
| 140 | if (config_cfattach_attach(fss_cd.cd_name, &fss_ca)) |
| 141 | aprint_error("%s: unable to register\n" , fss_cd.cd_name); |
| 142 | } |
| 143 | |
| 144 | static int |
| 145 | fss_match(device_t self, cfdata_t cfdata, void *aux) |
| 146 | { |
| 147 | return 1; |
| 148 | } |
| 149 | |
| 150 | static void |
| 151 | fss_attach(device_t parent, device_t self, void *aux) |
| 152 | { |
| 153 | struct fss_softc *sc = device_private(self); |
| 154 | |
| 155 | sc->sc_dev = self; |
| 156 | sc->sc_bdev = NODEV; |
| 157 | mutex_init(&sc->sc_slock, MUTEX_DEFAULT, IPL_NONE); |
| 158 | mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); |
| 159 | cv_init(&sc->sc_work_cv, "fssbs" ); |
| 160 | cv_init(&sc->sc_cache_cv, "cowwait" ); |
| 161 | bufq_alloc(&sc->sc_bufq, "fcfs" , 0); |
| 162 | sc->sc_dkdev = malloc(sizeof(*sc->sc_dkdev), M_DEVBUF, M_WAITOK); |
| 163 | sc->sc_dkdev->dk_info = NULL; |
| 164 | disk_init(sc->sc_dkdev, device_xname(self), NULL); |
| 165 | if (!pmf_device_register(self, NULL, NULL)) |
| 166 | aprint_error_dev(self, "couldn't establish power handler\n" ); |
| 167 | |
| 168 | if (fss_num_attached++ == 0) |
| 169 | vfs_hooks_attach(&fss_vfs_hooks); |
| 170 | } |
| 171 | |
| 172 | static int |
| 173 | fss_detach(device_t self, int flags) |
| 174 | { |
| 175 | struct fss_softc *sc = device_private(self); |
| 176 | |
| 177 | if (sc->sc_flags & FSS_ACTIVE) |
| 178 | return EBUSY; |
| 179 | |
| 180 | if (--fss_num_attached == 0) |
| 181 | vfs_hooks_detach(&fss_vfs_hooks); |
| 182 | |
| 183 | pmf_device_deregister(self); |
| 184 | mutex_destroy(&sc->sc_slock); |
| 185 | mutex_destroy(&sc->sc_lock); |
| 186 | cv_destroy(&sc->sc_work_cv); |
| 187 | cv_destroy(&sc->sc_cache_cv); |
| 188 | bufq_drain(sc->sc_bufq); |
| 189 | bufq_free(sc->sc_bufq); |
| 190 | disk_destroy(sc->sc_dkdev); |
| 191 | free(sc->sc_dkdev, M_DEVBUF); |
| 192 | |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | int |
| 197 | fss_open(dev_t dev, int flags, int mode, struct lwp *l) |
| 198 | { |
| 199 | int mflag; |
| 200 | cfdata_t cf; |
| 201 | struct fss_softc *sc; |
| 202 | |
| 203 | mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); |
| 204 | |
| 205 | mutex_enter(&fss_device_lock); |
| 206 | |
| 207 | sc = device_lookup_private(&fss_cd, minor(dev)); |
| 208 | if (sc == NULL) { |
| 209 | cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); |
| 210 | cf->cf_name = fss_cd.cd_name; |
| 211 | cf->cf_atname = fss_cd.cd_name; |
| 212 | cf->cf_unit = minor(dev); |
| 213 | cf->cf_fstate = FSTATE_STAR; |
| 214 | sc = device_private(config_attach_pseudo(cf)); |
| 215 | if (sc == NULL) { |
| 216 | mutex_exit(&fss_device_lock); |
| 217 | return ENOMEM; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | mutex_enter(&sc->sc_slock); |
| 222 | |
| 223 | sc->sc_flags |= mflag; |
| 224 | |
| 225 | mutex_exit(&sc->sc_slock); |
| 226 | mutex_exit(&fss_device_lock); |
| 227 | |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | int |
| 232 | fss_close(dev_t dev, int flags, int mode, struct lwp *l) |
| 233 | { |
| 234 | int mflag, error; |
| 235 | cfdata_t cf; |
| 236 | struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); |
| 237 | |
| 238 | mflag = (mode == S_IFCHR ? FSS_CDEV_OPEN : FSS_BDEV_OPEN); |
| 239 | error = 0; |
| 240 | |
| 241 | mutex_enter(&fss_device_lock); |
| 242 | restart: |
| 243 | mutex_enter(&sc->sc_slock); |
| 244 | if ((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) != mflag) { |
| 245 | sc->sc_flags &= ~mflag; |
| 246 | mutex_exit(&sc->sc_slock); |
| 247 | mutex_exit(&fss_device_lock); |
| 248 | return 0; |
| 249 | } |
| 250 | if ((sc->sc_flags & FSS_ACTIVE) != 0 && |
| 251 | (sc->sc_uflags & FSS_UNCONFIG_ON_CLOSE) != 0) { |
| 252 | sc->sc_uflags &= ~FSS_UNCONFIG_ON_CLOSE; |
| 253 | mutex_exit(&sc->sc_slock); |
| 254 | error = fss_ioctl(dev, FSSIOCCLR, NULL, FWRITE, l); |
| 255 | goto restart; |
| 256 | } |
| 257 | if ((sc->sc_flags & FSS_ACTIVE) != 0) { |
| 258 | mutex_exit(&sc->sc_slock); |
| 259 | mutex_exit(&fss_device_lock); |
| 260 | return error; |
| 261 | } |
| 262 | |
| 263 | KASSERT((sc->sc_flags & FSS_ACTIVE) == 0); |
| 264 | KASSERT((sc->sc_flags & (FSS_CDEV_OPEN|FSS_BDEV_OPEN)) == mflag); |
| 265 | mutex_exit(&sc->sc_slock); |
| 266 | cf = device_cfdata(sc->sc_dev); |
| 267 | error = config_detach(sc->sc_dev, DETACH_QUIET); |
| 268 | if (! error) |
| 269 | free(cf, M_DEVBUF); |
| 270 | mutex_exit(&fss_device_lock); |
| 271 | |
| 272 | return error; |
| 273 | } |
| 274 | |
| 275 | void |
| 276 | fss_strategy(struct buf *bp) |
| 277 | { |
| 278 | const bool write = ((bp->b_flags & B_READ) != B_READ); |
| 279 | struct fss_softc *sc = device_lookup_private(&fss_cd, minor(bp->b_dev)); |
| 280 | |
| 281 | mutex_enter(&sc->sc_slock); |
| 282 | |
| 283 | if (write || !FSS_ISVALID(sc)) { |
| 284 | |
| 285 | mutex_exit(&sc->sc_slock); |
| 286 | |
| 287 | bp->b_error = (write ? EROFS : ENXIO); |
| 288 | bp->b_resid = bp->b_bcount; |
| 289 | biodone(bp); |
| 290 | return; |
| 291 | } |
| 292 | |
| 293 | bp->b_rawblkno = bp->b_blkno; |
| 294 | bufq_put(sc->sc_bufq, bp); |
| 295 | cv_signal(&sc->sc_work_cv); |
| 296 | |
| 297 | mutex_exit(&sc->sc_slock); |
| 298 | } |
| 299 | |
| 300 | int |
| 301 | fss_read(dev_t dev, struct uio *uio, int flags) |
| 302 | { |
| 303 | return physio(fss_strategy, NULL, dev, B_READ, minphys, uio); |
| 304 | } |
| 305 | |
| 306 | int |
| 307 | fss_write(dev_t dev, struct uio *uio, int flags) |
| 308 | { |
| 309 | return physio(fss_strategy, NULL, dev, B_WRITE, minphys, uio); |
| 310 | } |
| 311 | |
| 312 | int |
| 313 | fss_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) |
| 314 | { |
| 315 | int error; |
| 316 | struct fss_softc *sc = device_lookup_private(&fss_cd, minor(dev)); |
| 317 | struct fss_set _fss; |
| 318 | struct fss_set *fss = (struct fss_set *)data; |
| 319 | struct fss_set50 *fss50 = (struct fss_set50 *)data; |
| 320 | struct fss_get *fsg = (struct fss_get *)data; |
| 321 | #ifndef _LP64 |
| 322 | struct fss_get50 *fsg50 = (struct fss_get50 *)data; |
| 323 | #endif |
| 324 | |
| 325 | switch (cmd) { |
| 326 | case FSSIOCSET50: |
| 327 | fss = &_fss; |
| 328 | fss->fss_mount = fss50->fss_mount; |
| 329 | fss->fss_bstore = fss50->fss_bstore; |
| 330 | fss->fss_csize = fss50->fss_csize; |
| 331 | fss->fss_flags = 0; |
| 332 | /* Fall through */ |
| 333 | case FSSIOCSET: |
| 334 | mutex_enter(&sc->sc_lock); |
| 335 | if ((flag & FWRITE) == 0) |
| 336 | error = EPERM; |
| 337 | else if ((sc->sc_flags & FSS_ACTIVE) != 0) |
| 338 | error = EBUSY; |
| 339 | else |
| 340 | error = fss_create_snapshot(sc, fss, l); |
| 341 | if (error == 0) |
| 342 | sc->sc_uflags = fss->fss_flags; |
| 343 | mutex_exit(&sc->sc_lock); |
| 344 | break; |
| 345 | |
| 346 | case FSSIOCCLR: |
| 347 | mutex_enter(&sc->sc_lock); |
| 348 | if ((flag & FWRITE) == 0) |
| 349 | error = EPERM; |
| 350 | else if ((sc->sc_flags & FSS_ACTIVE) == 0) |
| 351 | error = ENXIO; |
| 352 | else |
| 353 | error = fss_delete_snapshot(sc, l); |
| 354 | mutex_exit(&sc->sc_lock); |
| 355 | break; |
| 356 | |
| 357 | #ifndef _LP64 |
| 358 | case FSSIOCGET50: |
| 359 | mutex_enter(&sc->sc_lock); |
| 360 | switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { |
| 361 | case FSS_ACTIVE: |
| 362 | memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); |
| 363 | fsg50->fsg_csize = FSS_CLSIZE(sc); |
| 364 | timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); |
| 365 | fsg50->fsg_mount_size = sc->sc_clcount; |
| 366 | fsg50->fsg_bs_size = sc->sc_clnext; |
| 367 | error = 0; |
| 368 | break; |
| 369 | case FSS_PERSISTENT | FSS_ACTIVE: |
| 370 | memcpy(fsg50->fsg_mount, sc->sc_mntname, MNAMELEN); |
| 371 | fsg50->fsg_csize = 0; |
| 372 | timeval_to_timeval50(&sc->sc_time, &fsg50->fsg_time); |
| 373 | fsg50->fsg_mount_size = 0; |
| 374 | fsg50->fsg_bs_size = 0; |
| 375 | error = 0; |
| 376 | break; |
| 377 | default: |
| 378 | error = ENXIO; |
| 379 | break; |
| 380 | } |
| 381 | mutex_exit(&sc->sc_lock); |
| 382 | break; |
| 383 | #endif /* _LP64 */ |
| 384 | |
| 385 | case FSSIOCGET: |
| 386 | mutex_enter(&sc->sc_lock); |
| 387 | switch (sc->sc_flags & (FSS_PERSISTENT | FSS_ACTIVE)) { |
| 388 | case FSS_ACTIVE: |
| 389 | memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); |
| 390 | fsg->fsg_csize = FSS_CLSIZE(sc); |
| 391 | fsg->fsg_time = sc->sc_time; |
| 392 | fsg->fsg_mount_size = sc->sc_clcount; |
| 393 | fsg->fsg_bs_size = sc->sc_clnext; |
| 394 | error = 0; |
| 395 | break; |
| 396 | case FSS_PERSISTENT | FSS_ACTIVE: |
| 397 | memcpy(fsg->fsg_mount, sc->sc_mntname, MNAMELEN); |
| 398 | fsg->fsg_csize = 0; |
| 399 | fsg->fsg_time = sc->sc_time; |
| 400 | fsg->fsg_mount_size = 0; |
| 401 | fsg->fsg_bs_size = 0; |
| 402 | error = 0; |
| 403 | break; |
| 404 | default: |
| 405 | error = ENXIO; |
| 406 | break; |
| 407 | } |
| 408 | mutex_exit(&sc->sc_lock); |
| 409 | break; |
| 410 | |
| 411 | case FSSIOFSET: |
| 412 | mutex_enter(&sc->sc_slock); |
| 413 | sc->sc_uflags = *(int *)data; |
| 414 | mutex_exit(&sc->sc_slock); |
| 415 | error = 0; |
| 416 | break; |
| 417 | |
| 418 | case FSSIOFGET: |
| 419 | mutex_enter(&sc->sc_slock); |
| 420 | *(int *)data = sc->sc_uflags; |
| 421 | mutex_exit(&sc->sc_slock); |
| 422 | error = 0; |
| 423 | break; |
| 424 | |
| 425 | default: |
| 426 | error = EINVAL; |
| 427 | break; |
| 428 | } |
| 429 | |
| 430 | return error; |
| 431 | } |
| 432 | |
| 433 | int |
| 434 | fss_size(dev_t dev) |
| 435 | { |
| 436 | return -1; |
| 437 | } |
| 438 | |
| 439 | int |
| 440 | fss_dump(dev_t dev, daddr_t blkno, void *va, |
| 441 | size_t size) |
| 442 | { |
| 443 | return EROFS; |
| 444 | } |
| 445 | |
| 446 | /* |
| 447 | * An error occurred reading or writing the snapshot or backing store. |
| 448 | * If it is the first error log to console and disestablish cow handler. |
| 449 | * The caller holds the mutex. |
| 450 | */ |
| 451 | static inline void |
| 452 | fss_error(struct fss_softc *sc, const char *msg) |
| 453 | { |
| 454 | |
| 455 | if ((sc->sc_flags & (FSS_ACTIVE | FSS_ERROR)) != FSS_ACTIVE) |
| 456 | return; |
| 457 | |
| 458 | aprint_error_dev(sc->sc_dev, "snapshot invalid: %s\n" , msg); |
| 459 | if ((sc->sc_flags & FSS_PERSISTENT) == 0) |
| 460 | fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); |
| 461 | sc->sc_flags |= FSS_ERROR; |
| 462 | } |
| 463 | |
| 464 | /* |
| 465 | * Allocate the variable sized parts of the softc and |
| 466 | * fork the kernel thread. |
| 467 | * |
| 468 | * The fields sc_clcount, sc_clshift, sc_cache_size and sc_indir_size |
| 469 | * must be initialized. |
| 470 | */ |
| 471 | static int |
| 472 | fss_softc_alloc(struct fss_softc *sc) |
| 473 | { |
| 474 | int i, error; |
| 475 | |
| 476 | if ((sc->sc_flags & FSS_PERSISTENT) == 0) { |
| 477 | sc->sc_copied = |
| 478 | kmem_zalloc(howmany(sc->sc_clcount, NBBY), KM_SLEEP); |
| 479 | if (sc->sc_copied == NULL) |
| 480 | return(ENOMEM); |
| 481 | |
| 482 | sc->sc_cache = kmem_alloc(sc->sc_cache_size * |
| 483 | sizeof(struct fss_cache), KM_SLEEP); |
| 484 | if (sc->sc_cache == NULL) |
| 485 | return(ENOMEM); |
| 486 | |
| 487 | for (i = 0; i < sc->sc_cache_size; i++) { |
| 488 | sc->sc_cache[i].fc_type = FSS_CACHE_FREE; |
| 489 | sc->sc_cache[i].fc_data = |
| 490 | kmem_alloc(FSS_CLSIZE(sc), KM_SLEEP); |
| 491 | if (sc->sc_cache[i].fc_data == NULL) |
| 492 | return(ENOMEM); |
| 493 | cv_init(&sc->sc_cache[i].fc_state_cv, "cowwait1" ); |
| 494 | } |
| 495 | |
| 496 | sc->sc_indir_valid = |
| 497 | kmem_zalloc(howmany(sc->sc_indir_size, NBBY), KM_SLEEP); |
| 498 | if (sc->sc_indir_valid == NULL) |
| 499 | return(ENOMEM); |
| 500 | |
| 501 | sc->sc_indir_data = kmem_zalloc(FSS_CLSIZE(sc), KM_SLEEP); |
| 502 | if (sc->sc_indir_data == NULL) |
| 503 | return(ENOMEM); |
| 504 | } else { |
| 505 | sc->sc_copied = NULL; |
| 506 | sc->sc_cache = NULL; |
| 507 | sc->sc_indir_valid = NULL; |
| 508 | sc->sc_indir_data = NULL; |
| 509 | } |
| 510 | |
| 511 | sc->sc_flags |= FSS_BS_THREAD; |
| 512 | if ((error = kthread_create(PRI_BIO, KTHREAD_MUSTJOIN, NULL, |
| 513 | fss_bs_thread, sc, &sc->sc_bs_lwp, |
| 514 | "%s" , device_xname(sc->sc_dev))) != 0) { |
| 515 | sc->sc_flags &= ~FSS_BS_THREAD; |
| 516 | return error; |
| 517 | } |
| 518 | |
| 519 | disk_attach(sc->sc_dkdev); |
| 520 | |
| 521 | return 0; |
| 522 | } |
| 523 | |
| 524 | /* |
| 525 | * Free the variable sized parts of the softc. |
| 526 | */ |
| 527 | static void |
| 528 | fss_softc_free(struct fss_softc *sc) |
| 529 | { |
| 530 | int i; |
| 531 | |
| 532 | if ((sc->sc_flags & FSS_BS_THREAD) != 0) { |
| 533 | mutex_enter(&sc->sc_slock); |
| 534 | sc->sc_flags &= ~FSS_BS_THREAD; |
| 535 | cv_signal(&sc->sc_work_cv); |
| 536 | mutex_exit(&sc->sc_slock); |
| 537 | kthread_join(sc->sc_bs_lwp); |
| 538 | |
| 539 | disk_detach(sc->sc_dkdev); |
| 540 | } |
| 541 | |
| 542 | if (sc->sc_copied != NULL) |
| 543 | kmem_free(sc->sc_copied, howmany(sc->sc_clcount, NBBY)); |
| 544 | sc->sc_copied = NULL; |
| 545 | |
| 546 | if (sc->sc_cache != NULL) { |
| 547 | for (i = 0; i < sc->sc_cache_size; i++) |
| 548 | if (sc->sc_cache[i].fc_data != NULL) { |
| 549 | cv_destroy(&sc->sc_cache[i].fc_state_cv); |
| 550 | kmem_free(sc->sc_cache[i].fc_data, |
| 551 | FSS_CLSIZE(sc)); |
| 552 | } |
| 553 | kmem_free(sc->sc_cache, |
| 554 | sc->sc_cache_size*sizeof(struct fss_cache)); |
| 555 | } |
| 556 | sc->sc_cache = NULL; |
| 557 | |
| 558 | if (sc->sc_indir_valid != NULL) |
| 559 | kmem_free(sc->sc_indir_valid, howmany(sc->sc_indir_size, NBBY)); |
| 560 | sc->sc_indir_valid = NULL; |
| 561 | |
| 562 | if (sc->sc_indir_data != NULL) |
| 563 | kmem_free(sc->sc_indir_data, FSS_CLSIZE(sc)); |
| 564 | sc->sc_indir_data = NULL; |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * Set all active snapshots on this file system into ERROR state. |
| 569 | */ |
| 570 | static void |
| 571 | fss_unmount_hook(struct mount *mp) |
| 572 | { |
| 573 | int i; |
| 574 | struct fss_softc *sc; |
| 575 | |
| 576 | mutex_enter(&fss_device_lock); |
| 577 | for (i = 0; i < fss_cd.cd_ndevs; i++) { |
| 578 | if ((sc = device_lookup_private(&fss_cd, i)) == NULL) |
| 579 | continue; |
| 580 | mutex_enter(&sc->sc_slock); |
| 581 | if ((sc->sc_flags & FSS_ACTIVE) != 0 && sc->sc_mount == mp) |
| 582 | fss_error(sc, "forced by unmount" ); |
| 583 | mutex_exit(&sc->sc_slock); |
| 584 | } |
| 585 | mutex_exit(&fss_device_lock); |
| 586 | } |
| 587 | |
| 588 | /* |
| 589 | * A buffer is written to the snapshotted block device. Copy to |
| 590 | * backing store if needed. |
| 591 | */ |
| 592 | static int |
| 593 | fss_copy_on_write(void *v, struct buf *bp, bool data_valid) |
| 594 | { |
| 595 | int error; |
| 596 | u_int32_t cl, ch, c; |
| 597 | struct fss_softc *sc = v; |
| 598 | |
| 599 | mutex_enter(&sc->sc_slock); |
| 600 | if (!FSS_ISVALID(sc)) { |
| 601 | mutex_exit(&sc->sc_slock); |
| 602 | return 0; |
| 603 | } |
| 604 | |
| 605 | cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); |
| 606 | ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); |
| 607 | error = 0; |
| 608 | if (curlwp == uvm.pagedaemon_lwp) { |
| 609 | for (c = cl; c <= ch; c++) |
| 610 | if (isclr(sc->sc_copied, c)) { |
| 611 | error = ENOMEM; |
| 612 | break; |
| 613 | } |
| 614 | } |
| 615 | mutex_exit(&sc->sc_slock); |
| 616 | |
| 617 | if (error == 0) |
| 618 | for (c = cl; c <= ch; c++) { |
| 619 | error = fss_read_cluster(sc, c); |
| 620 | if (error) |
| 621 | break; |
| 622 | } |
| 623 | |
| 624 | return error; |
| 625 | } |
| 626 | |
| 627 | /* |
| 628 | * Lookup and open needed files. |
| 629 | * |
| 630 | * For file system internal snapshot initializes sc_mntname, sc_mount, |
| 631 | * sc_bs_vp and sc_time. |
| 632 | * |
| 633 | * Otherwise returns dev and size of the underlying block device. |
| 634 | * Initializes sc_mntname, sc_mount, sc_bdev, sc_bs_vp and sc_mount |
| 635 | */ |
| 636 | static int |
| 637 | fss_create_files(struct fss_softc *sc, struct fss_set *fss, |
| 638 | off_t *bsize, struct lwp *l) |
| 639 | { |
| 640 | int error, bits, fsbsize; |
| 641 | uint64_t numsec; |
| 642 | unsigned int secsize; |
| 643 | struct timespec ts; |
| 644 | /* nd -> nd2 to reduce mistakes while updating only some namei calls */ |
| 645 | struct pathbuf *pb2; |
| 646 | struct nameidata nd2; |
| 647 | struct vnode *vp; |
| 648 | |
| 649 | /* |
| 650 | * Get the mounted file system. |
| 651 | */ |
| 652 | |
| 653 | error = namei_simple_user(fss->fss_mount, |
| 654 | NSM_FOLLOW_NOEMULROOT, &vp); |
| 655 | if (error != 0) |
| 656 | return error; |
| 657 | |
| 658 | if ((vp->v_vflag & VV_ROOT) != VV_ROOT) { |
| 659 | vrele(vp); |
| 660 | return EINVAL; |
| 661 | } |
| 662 | |
| 663 | sc->sc_mount = vp->v_mount; |
| 664 | memcpy(sc->sc_mntname, sc->sc_mount->mnt_stat.f_mntonname, MNAMELEN); |
| 665 | |
| 666 | vrele(vp); |
| 667 | |
| 668 | /* |
| 669 | * Check for file system internal snapshot. |
| 670 | */ |
| 671 | |
| 672 | error = namei_simple_user(fss->fss_bstore, |
| 673 | NSM_FOLLOW_NOEMULROOT, &vp); |
| 674 | if (error != 0) |
| 675 | return error; |
| 676 | |
| 677 | if (vp->v_type == VREG && vp->v_mount == sc->sc_mount) { |
| 678 | sc->sc_flags |= FSS_PERSISTENT; |
| 679 | sc->sc_bs_vp = vp; |
| 680 | |
| 681 | fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; |
| 682 | bits = sizeof(sc->sc_bs_bshift)*NBBY; |
| 683 | for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < bits; |
| 684 | sc->sc_bs_bshift++) |
| 685 | if (FSS_FSBSIZE(sc) == fsbsize) |
| 686 | break; |
| 687 | if (sc->sc_bs_bshift >= bits) |
| 688 | return EINVAL; |
| 689 | |
| 690 | sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; |
| 691 | sc->sc_clshift = 0; |
| 692 | |
| 693 | if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { |
| 694 | error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); |
| 695 | if (error) |
| 696 | return error; |
| 697 | } |
| 698 | error = vn_lock(vp, LK_EXCLUSIVE); |
| 699 | if (error != 0) |
| 700 | return error; |
| 701 | error = VFS_SNAPSHOT(sc->sc_mount, sc->sc_bs_vp, &ts); |
| 702 | TIMESPEC_TO_TIMEVAL(&sc->sc_time, &ts); |
| 703 | |
| 704 | VOP_UNLOCK(sc->sc_bs_vp); |
| 705 | |
| 706 | return error; |
| 707 | } |
| 708 | vrele(vp); |
| 709 | |
| 710 | /* |
| 711 | * Get the block device it is mounted on and its size. |
| 712 | */ |
| 713 | |
| 714 | error = spec_node_lookup_by_mount(sc->sc_mount, &vp); |
| 715 | if (error) |
| 716 | return error; |
| 717 | sc->sc_bdev = vp->v_rdev; |
| 718 | |
| 719 | error = getdisksize(vp, &numsec, &secsize); |
| 720 | vrele(vp); |
| 721 | if (error) |
| 722 | return error; |
| 723 | |
| 724 | *bsize = (off_t)numsec*secsize; |
| 725 | |
| 726 | /* |
| 727 | * Get the backing store |
| 728 | */ |
| 729 | |
| 730 | error = pathbuf_copyin(fss->fss_bstore, &pb2); |
| 731 | if (error) { |
| 732 | return error; |
| 733 | } |
| 734 | NDINIT(&nd2, LOOKUP, FOLLOW, pb2); |
| 735 | if ((error = vn_open(&nd2, FREAD|FWRITE, 0)) != 0) { |
| 736 | pathbuf_destroy(pb2); |
| 737 | return error; |
| 738 | } |
| 739 | VOP_UNLOCK(nd2.ni_vp); |
| 740 | |
| 741 | sc->sc_bs_vp = nd2.ni_vp; |
| 742 | |
| 743 | if (nd2.ni_vp->v_type != VREG && nd2.ni_vp->v_type != VCHR) { |
| 744 | pathbuf_destroy(pb2); |
| 745 | return EINVAL; |
| 746 | } |
| 747 | pathbuf_destroy(pb2); |
| 748 | |
| 749 | if ((fss->fss_flags & FSS_UNLINK_ON_CREATE) != 0) { |
| 750 | error = do_sys_unlink(fss->fss_bstore, UIO_USERSPACE); |
| 751 | if (error) |
| 752 | return error; |
| 753 | } |
| 754 | if (sc->sc_bs_vp->v_type == VREG) { |
| 755 | fsbsize = sc->sc_bs_vp->v_mount->mnt_stat.f_iosize; |
| 756 | if (fsbsize & (fsbsize-1)) /* No power of two */ |
| 757 | return EINVAL; |
| 758 | for (sc->sc_bs_bshift = 1; sc->sc_bs_bshift < 32; |
| 759 | sc->sc_bs_bshift++) |
| 760 | if (FSS_FSBSIZE(sc) == fsbsize) |
| 761 | break; |
| 762 | if (sc->sc_bs_bshift >= 32) |
| 763 | return EINVAL; |
| 764 | sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; |
| 765 | } else { |
| 766 | sc->sc_bs_bshift = DEV_BSHIFT; |
| 767 | sc->sc_bs_bmask = FSS_FSBSIZE(sc)-1; |
| 768 | } |
| 769 | |
| 770 | return 0; |
| 771 | } |
| 772 | |
| 773 | /* |
| 774 | * Create a snapshot. |
| 775 | */ |
| 776 | static int |
| 777 | fss_create_snapshot(struct fss_softc *sc, struct fss_set *fss, struct lwp *l) |
| 778 | { |
| 779 | int len, error; |
| 780 | u_int32_t csize; |
| 781 | off_t bsize; |
| 782 | |
| 783 | bsize = 0; /* XXX gcc */ |
| 784 | |
| 785 | /* |
| 786 | * Open needed files. |
| 787 | */ |
| 788 | if ((error = fss_create_files(sc, fss, &bsize, l)) != 0) |
| 789 | goto bad; |
| 790 | |
| 791 | if (sc->sc_flags & FSS_PERSISTENT) { |
| 792 | fss_softc_alloc(sc); |
| 793 | sc->sc_flags |= FSS_ACTIVE; |
| 794 | return 0; |
| 795 | } |
| 796 | |
| 797 | /* |
| 798 | * Set cluster size. Must be a power of two and |
| 799 | * a multiple of backing store block size. |
| 800 | */ |
| 801 | if (fss->fss_csize <= 0) |
| 802 | csize = MAXPHYS; |
| 803 | else |
| 804 | csize = fss->fss_csize; |
| 805 | if (bsize/csize > FSS_CLUSTER_MAX) |
| 806 | csize = bsize/FSS_CLUSTER_MAX+1; |
| 807 | |
| 808 | for (sc->sc_clshift = sc->sc_bs_bshift; sc->sc_clshift < 32; |
| 809 | sc->sc_clshift++) |
| 810 | if (FSS_CLSIZE(sc) >= csize) |
| 811 | break; |
| 812 | if (sc->sc_clshift >= 32) { |
| 813 | error = EINVAL; |
| 814 | goto bad; |
| 815 | } |
| 816 | sc->sc_clmask = FSS_CLSIZE(sc)-1; |
| 817 | |
| 818 | /* |
| 819 | * Set number of cache slots. |
| 820 | */ |
| 821 | if (FSS_CLSIZE(sc) <= 8192) |
| 822 | sc->sc_cache_size = 32; |
| 823 | else if (FSS_CLSIZE(sc) <= 65536) |
| 824 | sc->sc_cache_size = 8; |
| 825 | else |
| 826 | sc->sc_cache_size = 4; |
| 827 | |
| 828 | /* |
| 829 | * Set number of clusters and size of last cluster. |
| 830 | */ |
| 831 | sc->sc_clcount = FSS_BTOCL(sc, bsize-1)+1; |
| 832 | sc->sc_clresid = FSS_CLOFF(sc, bsize-1)+1; |
| 833 | |
| 834 | /* |
| 835 | * Set size of indirect table. |
| 836 | */ |
| 837 | len = sc->sc_clcount*sizeof(u_int32_t); |
| 838 | sc->sc_indir_size = FSS_BTOCL(sc, len)+1; |
| 839 | sc->sc_clnext = sc->sc_indir_size; |
| 840 | sc->sc_indir_cur = 0; |
| 841 | |
| 842 | if ((error = fss_softc_alloc(sc)) != 0) |
| 843 | goto bad; |
| 844 | |
| 845 | /* |
| 846 | * Activate the snapshot. |
| 847 | */ |
| 848 | |
| 849 | if ((error = vfs_suspend(sc->sc_mount, 0)) != 0) |
| 850 | goto bad; |
| 851 | |
| 852 | microtime(&sc->sc_time); |
| 853 | |
| 854 | error = fscow_establish(sc->sc_mount, fss_copy_on_write, sc); |
| 855 | if (error == 0) |
| 856 | sc->sc_flags |= FSS_ACTIVE; |
| 857 | |
| 858 | vfs_resume(sc->sc_mount); |
| 859 | |
| 860 | if (error != 0) |
| 861 | goto bad; |
| 862 | |
| 863 | aprint_debug_dev(sc->sc_dev, "%s snapshot active\n" , sc->sc_mntname); |
| 864 | aprint_debug_dev(sc->sc_dev, |
| 865 | "%u clusters of %u, %u cache slots, %u indir clusters\n" , |
| 866 | sc->sc_clcount, FSS_CLSIZE(sc), |
| 867 | sc->sc_cache_size, sc->sc_indir_size); |
| 868 | |
| 869 | return 0; |
| 870 | |
| 871 | bad: |
| 872 | fss_softc_free(sc); |
| 873 | if (sc->sc_bs_vp != NULL) { |
| 874 | if (sc->sc_flags & FSS_PERSISTENT) |
| 875 | vrele(sc->sc_bs_vp); |
| 876 | else |
| 877 | vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); |
| 878 | } |
| 879 | sc->sc_bs_vp = NULL; |
| 880 | |
| 881 | return error; |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Delete a snapshot. |
| 886 | */ |
| 887 | static int |
| 888 | fss_delete_snapshot(struct fss_softc *sc, struct lwp *l) |
| 889 | { |
| 890 | |
| 891 | if ((sc->sc_flags & (FSS_PERSISTENT | FSS_ERROR)) == 0) |
| 892 | fscow_disestablish(sc->sc_mount, fss_copy_on_write, sc); |
| 893 | |
| 894 | mutex_enter(&sc->sc_slock); |
| 895 | sc->sc_flags &= ~(FSS_ACTIVE|FSS_ERROR); |
| 896 | sc->sc_mount = NULL; |
| 897 | sc->sc_bdev = NODEV; |
| 898 | mutex_exit(&sc->sc_slock); |
| 899 | |
| 900 | fss_softc_free(sc); |
| 901 | if (sc->sc_flags & FSS_PERSISTENT) |
| 902 | vrele(sc->sc_bs_vp); |
| 903 | else |
| 904 | vn_close(sc->sc_bs_vp, FREAD|FWRITE, l->l_cred); |
| 905 | sc->sc_bs_vp = NULL; |
| 906 | sc->sc_flags &= ~FSS_PERSISTENT; |
| 907 | |
| 908 | return 0; |
| 909 | } |
| 910 | |
| 911 | /* |
| 912 | * Read a cluster from the snapshotted block device to the cache. |
| 913 | */ |
| 914 | static int |
| 915 | fss_read_cluster(struct fss_softc *sc, u_int32_t cl) |
| 916 | { |
| 917 | int error, todo, offset, len; |
| 918 | daddr_t dblk; |
| 919 | struct buf *bp, *mbp; |
| 920 | struct fss_cache *scp, *scl; |
| 921 | |
| 922 | /* |
| 923 | * Get a free cache slot. |
| 924 | */ |
| 925 | scl = sc->sc_cache+sc->sc_cache_size; |
| 926 | |
| 927 | mutex_enter(&sc->sc_slock); |
| 928 | |
| 929 | restart: |
| 930 | if (isset(sc->sc_copied, cl) || !FSS_ISVALID(sc)) { |
| 931 | mutex_exit(&sc->sc_slock); |
| 932 | return 0; |
| 933 | } |
| 934 | |
| 935 | for (scp = sc->sc_cache; scp < scl; scp++) |
| 936 | if (scp->fc_cluster == cl) { |
| 937 | if (scp->fc_type == FSS_CACHE_VALID) { |
| 938 | mutex_exit(&sc->sc_slock); |
| 939 | return 0; |
| 940 | } else if (scp->fc_type == FSS_CACHE_BUSY) { |
| 941 | cv_wait(&scp->fc_state_cv, &sc->sc_slock); |
| 942 | goto restart; |
| 943 | } |
| 944 | } |
| 945 | |
| 946 | for (scp = sc->sc_cache; scp < scl; scp++) |
| 947 | if (scp->fc_type == FSS_CACHE_FREE) { |
| 948 | scp->fc_type = FSS_CACHE_BUSY; |
| 949 | scp->fc_cluster = cl; |
| 950 | break; |
| 951 | } |
| 952 | if (scp >= scl) { |
| 953 | cv_wait(&sc->sc_cache_cv, &sc->sc_slock); |
| 954 | goto restart; |
| 955 | } |
| 956 | |
| 957 | mutex_exit(&sc->sc_slock); |
| 958 | |
| 959 | /* |
| 960 | * Start the read. |
| 961 | */ |
| 962 | dblk = btodb(FSS_CLTOB(sc, cl)); |
| 963 | if (cl == sc->sc_clcount-1) { |
| 964 | todo = sc->sc_clresid; |
| 965 | memset((char *)scp->fc_data + todo, 0, FSS_CLSIZE(sc) - todo); |
| 966 | } else |
| 967 | todo = FSS_CLSIZE(sc); |
| 968 | offset = 0; |
| 969 | mbp = getiobuf(NULL, true); |
| 970 | mbp->b_bufsize = todo; |
| 971 | mbp->b_data = scp->fc_data; |
| 972 | mbp->b_resid = mbp->b_bcount = todo; |
| 973 | mbp->b_flags = B_READ; |
| 974 | mbp->b_cflags = BC_BUSY; |
| 975 | mbp->b_dev = sc->sc_bdev; |
| 976 | while (todo > 0) { |
| 977 | len = todo; |
| 978 | if (len > MAXPHYS) |
| 979 | len = MAXPHYS; |
| 980 | if (btodb(FSS_CLTOB(sc, cl)) == dblk && len == todo) |
| 981 | bp = mbp; |
| 982 | else { |
| 983 | bp = getiobuf(NULL, true); |
| 984 | nestiobuf_setup(mbp, bp, offset, len); |
| 985 | } |
| 986 | bp->b_lblkno = 0; |
| 987 | bp->b_blkno = dblk; |
| 988 | bdev_strategy(bp); |
| 989 | dblk += btodb(len); |
| 990 | offset += len; |
| 991 | todo -= len; |
| 992 | } |
| 993 | error = biowait(mbp); |
| 994 | putiobuf(mbp); |
| 995 | |
| 996 | mutex_enter(&sc->sc_slock); |
| 997 | scp->fc_type = (error ? FSS_CACHE_FREE : FSS_CACHE_VALID); |
| 998 | cv_broadcast(&scp->fc_state_cv); |
| 999 | if (error == 0) { |
| 1000 | setbit(sc->sc_copied, scp->fc_cluster); |
| 1001 | cv_signal(&sc->sc_work_cv); |
| 1002 | } |
| 1003 | mutex_exit(&sc->sc_slock); |
| 1004 | |
| 1005 | return error; |
| 1006 | } |
| 1007 | |
| 1008 | /* |
| 1009 | * Read/write clusters from/to backing store. |
| 1010 | * For persistent snapshots must be called with cl == 0. off is the |
| 1011 | * offset into the snapshot. |
| 1012 | */ |
| 1013 | static int |
| 1014 | fss_bs_io(struct fss_softc *sc, fss_io_type rw, |
| 1015 | u_int32_t cl, off_t off, int len, void *data) |
| 1016 | { |
| 1017 | int error; |
| 1018 | |
| 1019 | off += FSS_CLTOB(sc, cl); |
| 1020 | |
| 1021 | vn_lock(sc->sc_bs_vp, LK_EXCLUSIVE|LK_RETRY); |
| 1022 | |
| 1023 | error = vn_rdwr((rw == FSS_READ ? UIO_READ : UIO_WRITE), sc->sc_bs_vp, |
| 1024 | data, len, off, UIO_SYSSPACE, |
| 1025 | IO_ADV_ENCODE(POSIX_FADV_NOREUSE) | IO_NODELOCKED, |
| 1026 | sc->sc_bs_lwp->l_cred, NULL, NULL); |
| 1027 | if (error == 0) { |
| 1028 | mutex_enter(sc->sc_bs_vp->v_interlock); |
| 1029 | error = VOP_PUTPAGES(sc->sc_bs_vp, trunc_page(off), |
| 1030 | round_page(off+len), PGO_CLEANIT | PGO_FREE | PGO_SYNCIO); |
| 1031 | } |
| 1032 | |
| 1033 | VOP_UNLOCK(sc->sc_bs_vp); |
| 1034 | |
| 1035 | return error; |
| 1036 | } |
| 1037 | |
| 1038 | /* |
| 1039 | * Get a pointer to the indirect slot for this cluster. |
| 1040 | */ |
| 1041 | static u_int32_t * |
| 1042 | fss_bs_indir(struct fss_softc *sc, u_int32_t cl) |
| 1043 | { |
| 1044 | u_int32_t icl; |
| 1045 | int ioff; |
| 1046 | |
| 1047 | icl = cl/(FSS_CLSIZE(sc)/sizeof(u_int32_t)); |
| 1048 | ioff = cl%(FSS_CLSIZE(sc)/sizeof(u_int32_t)); |
| 1049 | |
| 1050 | if (sc->sc_indir_cur == icl) |
| 1051 | return &sc->sc_indir_data[ioff]; |
| 1052 | |
| 1053 | if (sc->sc_indir_dirty) { |
| 1054 | if (fss_bs_io(sc, FSS_WRITE, sc->sc_indir_cur, 0, |
| 1055 | FSS_CLSIZE(sc), (void *)sc->sc_indir_data) != 0) |
| 1056 | return NULL; |
| 1057 | setbit(sc->sc_indir_valid, sc->sc_indir_cur); |
| 1058 | } |
| 1059 | |
| 1060 | sc->sc_indir_dirty = 0; |
| 1061 | sc->sc_indir_cur = icl; |
| 1062 | |
| 1063 | if (isset(sc->sc_indir_valid, sc->sc_indir_cur)) { |
| 1064 | if (fss_bs_io(sc, FSS_READ, sc->sc_indir_cur, 0, |
| 1065 | FSS_CLSIZE(sc), (void *)sc->sc_indir_data) != 0) |
| 1066 | return NULL; |
| 1067 | } else |
| 1068 | memset(sc->sc_indir_data, 0, FSS_CLSIZE(sc)); |
| 1069 | |
| 1070 | return &sc->sc_indir_data[ioff]; |
| 1071 | } |
| 1072 | |
| 1073 | /* |
| 1074 | * The kernel thread (one for every active snapshot). |
| 1075 | * |
| 1076 | * After wakeup it cleans the cache and runs the I/O requests. |
| 1077 | */ |
| 1078 | static void |
| 1079 | fss_bs_thread(void *arg) |
| 1080 | { |
| 1081 | bool thread_idle, is_valid; |
| 1082 | int error, i, todo, len, crotor, is_read; |
| 1083 | long off; |
| 1084 | char *addr; |
| 1085 | u_int32_t c, cl, ch, *indirp; |
| 1086 | struct buf *bp, *nbp; |
| 1087 | struct fss_softc *sc; |
| 1088 | struct fss_cache *scp, *scl; |
| 1089 | |
| 1090 | sc = arg; |
| 1091 | scl = sc->sc_cache+sc->sc_cache_size; |
| 1092 | crotor = 0; |
| 1093 | thread_idle = false; |
| 1094 | |
| 1095 | mutex_enter(&sc->sc_slock); |
| 1096 | |
| 1097 | for (;;) { |
| 1098 | if (thread_idle) |
| 1099 | cv_wait(&sc->sc_work_cv, &sc->sc_slock); |
| 1100 | thread_idle = true; |
| 1101 | if ((sc->sc_flags & FSS_BS_THREAD) == 0) { |
| 1102 | mutex_exit(&sc->sc_slock); |
| 1103 | kthread_exit(0); |
| 1104 | } |
| 1105 | |
| 1106 | /* |
| 1107 | * Process I/O requests (persistent) |
| 1108 | */ |
| 1109 | |
| 1110 | if (sc->sc_flags & FSS_PERSISTENT) { |
| 1111 | if ((bp = bufq_get(sc->sc_bufq)) == NULL) |
| 1112 | continue; |
| 1113 | is_valid = FSS_ISVALID(sc); |
| 1114 | is_read = (bp->b_flags & B_READ); |
| 1115 | thread_idle = false; |
| 1116 | mutex_exit(&sc->sc_slock); |
| 1117 | |
| 1118 | if (is_valid) { |
| 1119 | disk_busy(sc->sc_dkdev); |
| 1120 | error = fss_bs_io(sc, FSS_READ, 0, |
| 1121 | dbtob(bp->b_blkno), bp->b_bcount, |
| 1122 | bp->b_data); |
| 1123 | disk_unbusy(sc->sc_dkdev, |
| 1124 | (error ? 0 : bp->b_bcount), is_read); |
| 1125 | } else |
| 1126 | error = ENXIO; |
| 1127 | |
| 1128 | bp->b_error = error; |
| 1129 | bp->b_resid = (error ? bp->b_bcount : 0); |
| 1130 | biodone(bp); |
| 1131 | |
| 1132 | mutex_enter(&sc->sc_slock); |
| 1133 | continue; |
| 1134 | } |
| 1135 | |
| 1136 | /* |
| 1137 | * Clean the cache |
| 1138 | */ |
| 1139 | for (i = 0; i < sc->sc_cache_size; i++) { |
| 1140 | crotor = (crotor + 1) % sc->sc_cache_size; |
| 1141 | scp = sc->sc_cache + crotor; |
| 1142 | if (scp->fc_type != FSS_CACHE_VALID) |
| 1143 | continue; |
| 1144 | mutex_exit(&sc->sc_slock); |
| 1145 | |
| 1146 | thread_idle = false; |
| 1147 | indirp = fss_bs_indir(sc, scp->fc_cluster); |
| 1148 | if (indirp != NULL) { |
| 1149 | error = fss_bs_io(sc, FSS_WRITE, sc->sc_clnext, |
| 1150 | 0, FSS_CLSIZE(sc), scp->fc_data); |
| 1151 | } else |
| 1152 | error = EIO; |
| 1153 | |
| 1154 | mutex_enter(&sc->sc_slock); |
| 1155 | if (error == 0) { |
| 1156 | *indirp = sc->sc_clnext++; |
| 1157 | sc->sc_indir_dirty = 1; |
| 1158 | } else |
| 1159 | fss_error(sc, "write error on backing store" ); |
| 1160 | |
| 1161 | scp->fc_type = FSS_CACHE_FREE; |
| 1162 | cv_broadcast(&sc->sc_cache_cv); |
| 1163 | break; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * Process I/O requests |
| 1168 | */ |
| 1169 | if ((bp = bufq_get(sc->sc_bufq)) == NULL) |
| 1170 | continue; |
| 1171 | is_valid = FSS_ISVALID(sc); |
| 1172 | is_read = (bp->b_flags & B_READ); |
| 1173 | thread_idle = false; |
| 1174 | |
| 1175 | if (!is_valid) { |
| 1176 | mutex_exit(&sc->sc_slock); |
| 1177 | |
| 1178 | bp->b_error = ENXIO; |
| 1179 | bp->b_resid = bp->b_bcount; |
| 1180 | biodone(bp); |
| 1181 | |
| 1182 | mutex_enter(&sc->sc_slock); |
| 1183 | continue; |
| 1184 | } |
| 1185 | |
| 1186 | disk_busy(sc->sc_dkdev); |
| 1187 | |
| 1188 | /* |
| 1189 | * First read from the snapshotted block device unless |
| 1190 | * this request is completely covered by backing store. |
| 1191 | */ |
| 1192 | |
| 1193 | cl = FSS_BTOCL(sc, dbtob(bp->b_blkno)); |
| 1194 | off = FSS_CLOFF(sc, dbtob(bp->b_blkno)); |
| 1195 | ch = FSS_BTOCL(sc, dbtob(bp->b_blkno)+bp->b_bcount-1); |
| 1196 | error = 0; |
| 1197 | bp->b_resid = 0; |
| 1198 | bp->b_error = 0; |
| 1199 | for (c = cl; c <= ch; c++) { |
| 1200 | if (isset(sc->sc_copied, c)) |
| 1201 | continue; |
| 1202 | mutex_exit(&sc->sc_slock); |
| 1203 | |
| 1204 | /* Not on backing store, read from device. */ |
| 1205 | nbp = getiobuf(NULL, true); |
| 1206 | nbp->b_flags = B_READ; |
| 1207 | nbp->b_resid = nbp->b_bcount = bp->b_bcount; |
| 1208 | nbp->b_bufsize = bp->b_bcount; |
| 1209 | nbp->b_data = bp->b_data; |
| 1210 | nbp->b_blkno = bp->b_blkno; |
| 1211 | nbp->b_lblkno = 0; |
| 1212 | nbp->b_dev = sc->sc_bdev; |
| 1213 | SET(nbp->b_cflags, BC_BUSY); /* mark buffer busy */ |
| 1214 | |
| 1215 | bdev_strategy(nbp); |
| 1216 | |
| 1217 | error = biowait(nbp); |
| 1218 | if (error != 0) { |
| 1219 | bp->b_resid = bp->b_bcount; |
| 1220 | bp->b_error = nbp->b_error; |
| 1221 | disk_unbusy(sc->sc_dkdev, 0, is_read); |
| 1222 | biodone(bp); |
| 1223 | } |
| 1224 | putiobuf(nbp); |
| 1225 | |
| 1226 | mutex_enter(&sc->sc_slock); |
| 1227 | break; |
| 1228 | } |
| 1229 | if (error) |
| 1230 | continue; |
| 1231 | |
| 1232 | /* |
| 1233 | * Replace those parts that have been saved to backing store. |
| 1234 | */ |
| 1235 | |
| 1236 | addr = bp->b_data; |
| 1237 | todo = bp->b_bcount; |
| 1238 | for (c = cl; c <= ch; c++, off = 0, todo -= len, addr += len) { |
| 1239 | len = FSS_CLSIZE(sc)-off; |
| 1240 | if (len > todo) |
| 1241 | len = todo; |
| 1242 | if (isclr(sc->sc_copied, c)) |
| 1243 | continue; |
| 1244 | mutex_exit(&sc->sc_slock); |
| 1245 | |
| 1246 | indirp = fss_bs_indir(sc, c); |
| 1247 | if (indirp == NULL || *indirp == 0) { |
| 1248 | /* |
| 1249 | * Not on backing store. Either in cache |
| 1250 | * or hole in the snapshotted block device. |
| 1251 | */ |
| 1252 | |
| 1253 | mutex_enter(&sc->sc_slock); |
| 1254 | for (scp = sc->sc_cache; scp < scl; scp++) |
| 1255 | if (scp->fc_type == FSS_CACHE_VALID && |
| 1256 | scp->fc_cluster == c) |
| 1257 | break; |
| 1258 | if (scp < scl) |
| 1259 | memcpy(addr, (char *)scp->fc_data+off, |
| 1260 | len); |
| 1261 | else |
| 1262 | memset(addr, 0, len); |
| 1263 | continue; |
| 1264 | } |
| 1265 | |
| 1266 | /* |
| 1267 | * Read from backing store. |
| 1268 | */ |
| 1269 | error = |
| 1270 | fss_bs_io(sc, FSS_READ, *indirp, off, len, addr); |
| 1271 | |
| 1272 | mutex_enter(&sc->sc_slock); |
| 1273 | if (error) { |
| 1274 | bp->b_resid = bp->b_bcount; |
| 1275 | bp->b_error = error; |
| 1276 | break; |
| 1277 | } |
| 1278 | } |
| 1279 | mutex_exit(&sc->sc_slock); |
| 1280 | |
| 1281 | disk_unbusy(sc->sc_dkdev, (error ? 0 : bp->b_bcount), is_read); |
| 1282 | biodone(bp); |
| 1283 | |
| 1284 | mutex_enter(&sc->sc_slock); |
| 1285 | } |
| 1286 | } |
| 1287 | |
| 1288 | #ifdef _MODULE |
| 1289 | |
| 1290 | #include <sys/module.h> |
| 1291 | |
| 1292 | MODULE(MODULE_CLASS_DRIVER, fss, NULL); |
| 1293 | CFDRIVER_DECL(fss, DV_DISK, NULL); |
| 1294 | |
| 1295 | devmajor_t fss_bmajor = -1, fss_cmajor = -1; |
| 1296 | |
| 1297 | static int |
| 1298 | fss_modcmd(modcmd_t cmd, void *arg) |
| 1299 | { |
| 1300 | int error = 0; |
| 1301 | |
| 1302 | switch (cmd) { |
| 1303 | case MODULE_CMD_INIT: |
| 1304 | mutex_init(&fss_device_lock, MUTEX_DEFAULT, IPL_NONE); |
| 1305 | error = config_cfdriver_attach(&fss_cd); |
| 1306 | if (error) { |
| 1307 | mutex_destroy(&fss_device_lock); |
| 1308 | break; |
| 1309 | } |
| 1310 | error = config_cfattach_attach(fss_cd.cd_name, &fss_ca); |
| 1311 | if (error) { |
| 1312 | config_cfdriver_detach(&fss_cd); |
| 1313 | mutex_destroy(&fss_device_lock); |
| 1314 | break; |
| 1315 | } |
| 1316 | error = devsw_attach(fss_cd.cd_name, |
| 1317 | &fss_bdevsw, &fss_bmajor, &fss_cdevsw, &fss_cmajor); |
| 1318 | |
| 1319 | if (error) { |
| 1320 | config_cfattach_detach(fss_cd.cd_name, &fss_ca); |
| 1321 | config_cfdriver_detach(&fss_cd); |
| 1322 | mutex_destroy(&fss_device_lock); |
| 1323 | break; |
| 1324 | } |
| 1325 | break; |
| 1326 | |
| 1327 | case MODULE_CMD_FINI: |
| 1328 | devsw_detach(&fss_bdevsw, &fss_cdevsw); |
| 1329 | error = config_cfattach_detach(fss_cd.cd_name, &fss_ca); |
| 1330 | if (error) { |
| 1331 | devsw_attach(fss_cd.cd_name, &fss_bdevsw, &fss_bmajor, |
| 1332 | &fss_cdevsw, &fss_cmajor); |
| 1333 | break; |
| 1334 | } |
| 1335 | config_cfdriver_detach(&fss_cd); |
| 1336 | mutex_destroy(&fss_device_lock); |
| 1337 | break; |
| 1338 | |
| 1339 | default: |
| 1340 | error = ENOTTY; |
| 1341 | break; |
| 1342 | } |
| 1343 | |
| 1344 | return error; |
| 1345 | } |
| 1346 | |
| 1347 | #endif /* _MODULE */ |
| 1348 | |