| 1 | /* |
| 2 | * Copyright (c) 2008 The DragonFly Project. All rights reserved. |
| 3 | * |
| 4 | * This code is derived from software contributed to The DragonFly Project |
| 5 | * by Matthew Dillon <dillon@backplane.com> |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * 3. Neither the name of The DragonFly Project nor the names of its |
| 18 | * contributors may be used to endorse or promote products derived |
| 19 | * from this software without specific, prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 22 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 24 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 25 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 26 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 27 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 28 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 29 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 30 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 31 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | * |
| 34 | * $DragonFly: src/sys/vfs/hammer/hammer_recover.c,v 1.29 2008/07/26 05:36:21 dillon Exp $ |
| 35 | */ |
| 36 | |
| 37 | #include "hammer.h" |
| 38 | |
| 39 | static int hammer_check_tail_signature(hammer_fifo_tail_t tail, |
| 40 | hammer_off_t end_off); |
| 41 | static int hammer_check_head_signature(hammer_fifo_head_t head, |
| 42 | hammer_off_t beg_off); |
| 43 | static void hammer_recover_copy_undo(hammer_off_t undo_offset, |
| 44 | char *src, char *dst, int bytes); |
| 45 | static hammer_fifo_any_t hammer_recover_scan_fwd(hammer_mount_t hmp, |
| 46 | hammer_volume_t root_volume, |
| 47 | hammer_off_t *scan_offsetp, |
| 48 | int *errorp, struct hammer_buffer **bufferp); |
| 49 | static hammer_fifo_any_t hammer_recover_scan_rev(hammer_mount_t hmp, |
| 50 | hammer_volume_t root_volume, |
| 51 | hammer_off_t *scan_offsetp, |
| 52 | int *errorp, struct hammer_buffer **bufferp); |
| 53 | #if 0 |
| 54 | static void hammer_recover_debug_dump(int w, char *buf, int bytes); |
| 55 | #endif |
| 56 | static int hammer_recover_undo(hammer_mount_t hmp, hammer_volume_t root_volume, |
| 57 | hammer_fifo_undo_t undo); |
| 58 | |
| 59 | /* |
| 60 | * Recover filesystem meta-data on mount. This procedure figures out the |
| 61 | * UNDO FIFO range and runs the UNDOs backwards. The FIFO pointers are not |
| 62 | * resynchronized by this procedure. |
| 63 | * |
| 64 | * This procedure is run near the beginning of the mount sequence, before |
| 65 | * any B-Tree or high-level accesses are enabled, and is responsible for |
| 66 | * restoring the meta-data to a consistent state. High level HAMMER data |
| 67 | * structures (such as the B-Tree) cannot be accessed here. |
| 68 | * |
| 69 | * NOTE: No information from the root volume has been cached in the |
| 70 | * hammer_mount structure yet, so we need to access the root volume's |
| 71 | * buffer directly. |
| 72 | * |
| 73 | * NOTE: |
| 74 | */ |
| 75 | int |
| 76 | hammer_recover_stage1(hammer_mount_t hmp, hammer_volume_t root_volume) |
| 77 | { |
| 78 | hammer_blockmap_t rootmap; |
| 79 | hammer_buffer_t buffer; |
| 80 | hammer_off_t scan_offset; |
| 81 | hammer_off_t scan_offset_save; |
| 82 | hammer_off_t bytes; |
| 83 | hammer_fifo_any_t head; |
| 84 | hammer_off_t first_offset; |
| 85 | hammer_off_t last_offset; |
| 86 | u_int32_t seqno; |
| 87 | int error; |
| 88 | |
| 89 | /* |
| 90 | * Examine the UNDO FIFO indices in the volume header. |
| 91 | */ |
| 92 | rootmap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; |
| 93 | first_offset = rootmap->first_offset; |
| 94 | last_offset = rootmap->next_offset; |
| 95 | buffer = NULL; |
| 96 | error = 0; |
| 97 | |
| 98 | if (first_offset > rootmap->alloc_offset || |
| 99 | last_offset > rootmap->alloc_offset) { |
| 100 | kprintf("HAMMER(%s) Illegal UNDO FIFO index range " |
| 101 | "%016jx, %016jx limit %016jx\n", |
| 102 | root_volume->ondisk->vol_name, |
| 103 | (intmax_t)first_offset, |
| 104 | (intmax_t)last_offset, |
| 105 | (intmax_t)rootmap->alloc_offset); |
| 106 | error = EIO; |
| 107 | goto done; |
| 108 | } |
| 109 | |
| 110 | /* |
| 111 | * In HAMMER version 4+ filesystems the volume header does NOT |
| 112 | * contain definitive UNDO FIFO state. In particular, the |
| 113 | * rootmap->next_offset may not be indexed completely to the |
| 114 | * end of the active UNDO FIFO. |
| 115 | */ |
| 116 | if (hmp->version >= HAMMER_VOL_VERSION_FOUR) { |
| 117 | /* |
| 118 | * To find the definitive range we must first scan backwards |
| 119 | * from first_offset to locate the first real record and |
| 120 | * extract the sequence number from it. This record is not |
| 121 | * part of the active undo space. |
| 122 | */ |
| 123 | scan_offset = first_offset; |
| 124 | seqno = 0; |
| 125 | |
| 126 | for (;;) { |
| 127 | head = hammer_recover_scan_rev(hmp, root_volume, |
| 128 | &scan_offset, |
| 129 | &error, &buffer); |
| 130 | if (error) |
| 131 | break; |
| 132 | if (head->head.hdr_type != HAMMER_HEAD_TYPE_PAD) { |
| 133 | seqno = head->head.hdr_seq; |
| 134 | break; |
| 135 | } |
| 136 | } |
| 137 | if (error) { |
| 138 | kprintf("HAMMER(%s) meta-data recovery failure " |
| 139 | "during seqno backscan\n", |
| 140 | root_volume->ondisk->vol_name); |
| 141 | goto done; |
| 142 | } |
| 143 | |
| 144 | /* |
| 145 | * Scan forwards from first_offset and (seqno+1) looking |
| 146 | * for a sequence space discontinuity. This denotes the |
| 147 | * end of the active FIFO area. |
| 148 | * |
| 149 | * NOTE: For the case where the FIFO is empty the very first |
| 150 | * record we find will be discontinuous. |
| 151 | * |
| 152 | * NOTE: Do not include trailing PADs in the scan range, |
| 153 | * and remember the returned scan_offset after a |
| 154 | * fwd iteration points to the end of the returned |
| 155 | * record. |
| 156 | */ |
| 157 | kprintf("HAMMER(%s) meta-data recovery check seqno=%08x\n", |
| 158 | root_volume->ondisk->vol_name, |
| 159 | seqno); |
| 160 | |
| 161 | scan_offset = first_offset; |
| 162 | scan_offset_save = scan_offset; |
| 163 | ++seqno; |
| 164 | for (;;) { |
| 165 | head = hammer_recover_scan_fwd(hmp, root_volume, |
| 166 | &scan_offset, |
| 167 | &error, &buffer); |
| 168 | if (error) |
| 169 | break; |
| 170 | if (head->head.hdr_type != HAMMER_HEAD_TYPE_PAD) { |
| 171 | if (seqno != head->head.hdr_seq) { |
| 172 | scan_offset = scan_offset_save; |
| 173 | break; |
| 174 | } |
| 175 | scan_offset_save = scan_offset; |
| 176 | ++seqno; |
| 177 | } |
| 178 | |
| 179 | #if 0 |
| 180 | /* |
| 181 | * If the forward scan is grossly ahead of last_offset |
| 182 | * then something is wrong. last_offset is supposed |
| 183 | * to be flushed out |
| 184 | */ |
| 185 | if (last_offset >= scan_offset) { |
| 186 | bytes = last_offset - scan_offset; |
| 187 | } else { |
| 188 | bytes = rootmap->alloc_offset - scan_offset + |
| 189 | (last_offset & HAMMER_OFF_LONG_MASK); |
| 190 | } |
| 191 | if (bytes > |
| 192 | (rootmap->alloc_offset & HAMMER_OFF_LONG_MASK) * |
| 193 | 4 / 5) { |
| 194 | kprintf("HAMMER(%s) meta-data forward scan is " |
| 195 | "grossly beyond the last_offset in " |
| 196 | "the volume header, this can't be " |
| 197 | "right.\n", |
| 198 | root_volume->ondisk->vol_name); |
| 199 | error = EIO; |
| 200 | break; |
| 201 | } |
| 202 | #endif |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Store the seqno. This will be the next seqno we lay down |
| 207 | * when generating new UNDOs. |
| 208 | */ |
| 209 | hmp->undo_seqno = seqno; |
| 210 | if (error) { |
| 211 | kprintf("HAMMER(%s) meta-data recovery failure " |
| 212 | "during seqno fwdscan\n", |
| 213 | root_volume->ondisk->vol_name); |
| 214 | goto done; |
| 215 | } |
| 216 | last_offset = scan_offset; |
| 217 | kprintf("HAMMER(%s) meta-data recovery range %016jx-%016jx " |
| 218 | "(invol %016jx) endseqno=%08x\n", |
| 219 | root_volume->ondisk->vol_name, |
| 220 | (intmax_t)first_offset, |
| 221 | (intmax_t)last_offset, |
| 222 | (intmax_t)rootmap->next_offset, |
| 223 | seqno); |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Calculate the size of the active portion of the FIFO. If the |
| 228 | * FIFO is empty the filesystem is clean and no further action is |
| 229 | * needed. |
| 230 | */ |
| 231 | if (last_offset >= first_offset) { |
| 232 | bytes = last_offset - first_offset; |
| 233 | } else { |
| 234 | bytes = rootmap->alloc_offset - first_offset + |
| 235 | (last_offset & HAMMER_OFF_LONG_MASK); |
| 236 | } |
| 237 | if (bytes == 0) { |
| 238 | error = 0; |
| 239 | goto done; |
| 240 | } |
| 241 | |
| 242 | kprintf("HAMMER(%s) Start meta-data recovery %016jx - %016jx " |
| 243 | "(%jd bytes of UNDO)%s\n", |
| 244 | root_volume->ondisk->vol_name, |
| 245 | (intmax_t)first_offset, |
| 246 | (intmax_t)last_offset, |
| 247 | (intmax_t)bytes, |
| 248 | (hmp->ronly ? " (RO)" : "(RW)")); |
| 249 | if (bytes > (rootmap->alloc_offset & HAMMER_OFF_LONG_MASK)) { |
| 250 | kprintf("Undo size is absurd, unable to mount\n"); |
| 251 | error = EIO; |
| 252 | goto done; |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | * Scan the UNDOs backwards. |
| 257 | */ |
| 258 | scan_offset = last_offset; |
| 259 | |
| 260 | while ((int64_t)bytes > 0) { |
| 261 | KKASSERT(scan_offset != first_offset); |
| 262 | head = hammer_recover_scan_rev(hmp, root_volume, |
| 263 | &scan_offset, &error, &buffer); |
| 264 | if (error) |
| 265 | break; |
| 266 | error = hammer_recover_undo(hmp, root_volume, &head->undo); |
| 267 | if (error) { |
| 268 | kprintf("HAMMER(%s) UNDO record at %016jx failed\n", |
| 269 | root_volume->ondisk->vol_name, |
| 270 | (intmax_t)scan_offset - head->head.hdr_size); |
| 271 | break; |
| 272 | } |
| 273 | bytes -= head->head.hdr_size; |
| 274 | |
| 275 | /* |
| 276 | * If too many dirty buffers have built up we have to flush'm |
| 277 | * out. As long as we do not flush out the volume header |
| 278 | * a crash here should not cause any problems. |
| 279 | * |
| 280 | * buffer must be released so the flush can assert that |
| 281 | * all buffers are idle. |
| 282 | */ |
| 283 | if (hammer_flusher_meta_limit(hmp)) { |
| 284 | if (buffer) { |
| 285 | hammer_rel_buffer(buffer, 0); |
| 286 | buffer = NULL; |
| 287 | } |
| 288 | if (hmp->ronly == 0) { |
| 289 | hammer_recover_flush_buffers(hmp, root_volume, |
| 290 | 0); |
| 291 | kprintf("HAMMER(%s) Continuing recovery\n", |
| 292 | root_volume->ondisk->vol_name); |
| 293 | } else { |
| 294 | kprintf("HAMMER(%s) Recovery failure: Insufficient buffer cache to hold dirty buffers on read-only mount!\n", |
| 295 | root_volume->ondisk->vol_name); |
| 296 | error = EIO; |
| 297 | break; |
| 298 | } |
| 299 | } |
| 300 | } |
| 301 | done: |
| 302 | if (buffer) { |
| 303 | hammer_rel_buffer(buffer, 0); |
| 304 | buffer = NULL; |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * After completely flushing all the recovered buffers the volume |
| 309 | * header will also be flushed. |
| 310 | */ |
| 311 | if (root_volume->io.recovered == 0) { |
| 312 | hammer_ref_volume(root_volume); |
| 313 | root_volume->io.recovered = 1; |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Finish up flushing (or discarding) recovered buffers. FIFO |
| 318 | * indices in the volume header are updated to the actual undo |
| 319 | * range but will not be collapsed until stage 2. |
| 320 | */ |
| 321 | if (error == 0) { |
| 322 | hammer_modify_volume(NULL, root_volume, NULL, 0); |
| 323 | rootmap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; |
| 324 | rootmap->first_offset = first_offset; |
| 325 | rootmap->next_offset = last_offset; |
| 326 | hammer_modify_volume_done(root_volume); |
| 327 | if (hmp->ronly == 0) |
| 328 | hammer_recover_flush_buffers(hmp, root_volume, 1); |
| 329 | } else { |
| 330 | hammer_recover_flush_buffers(hmp, root_volume, -1); |
| 331 | } |
| 332 | kprintf("HAMMER(%s) End meta-data recovery\n", |
| 333 | root_volume->ondisk->vol_name); |
| 334 | return (error); |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * Execute redo operations |
| 339 | * |
| 340 | * This procedure is run at the end of the mount sequence, after the hammer |
| 341 | * mount structure has been completely initialized but before the filesystem |
| 342 | * goes live. It can access standard cursors, the B-Tree, flush the |
| 343 | * filesystem, and so forth. |
| 344 | * |
| 345 | * This code may only be called for read-write mounts or when a mount |
| 346 | * switches from read-only to read-write. |
| 347 | * |
| 348 | * The stage1 code will have already calculated the correct FIFO range |
| 349 | * and stored it in the rootmap. |
| 350 | */ |
| 351 | int |
| 352 | hammer_recover_stage2(hammer_mount_t hmp, hammer_volume_t root_volume) |
| 353 | { |
| 354 | hammer_blockmap_t rootmap; |
| 355 | hammer_buffer_t buffer; |
| 356 | hammer_off_t scan_offset; |
| 357 | hammer_off_t bytes; |
| 358 | hammer_fifo_any_t head; |
| 359 | hammer_off_t first_offset; |
| 360 | hammer_off_t last_offset; |
| 361 | int error; |
| 362 | |
| 363 | /* |
| 364 | * Stage 2 can only be run on a RW mount, or when the mount is |
| 365 | * switched from RO to RW. It must be run only once. |
| 366 | */ |
| 367 | KKASSERT(hmp->ronly == 0); |
| 368 | |
| 369 | if (hmp->hflags & HMNT_STAGE2) |
| 370 | return(0); |
| 371 | hmp->hflags |= HMNT_STAGE2; |
| 372 | |
| 373 | /* |
| 374 | * Examine the UNDO FIFO. If it is empty the filesystem is clean |
| 375 | * and no action need be taken. |
| 376 | */ |
| 377 | rootmap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; |
| 378 | first_offset = rootmap->first_offset; |
| 379 | last_offset = rootmap->next_offset; |
| 380 | if (first_offset == last_offset) |
| 381 | return(0); |
| 382 | |
| 383 | if (last_offset >= first_offset) { |
| 384 | bytes = last_offset - first_offset; |
| 385 | } else { |
| 386 | bytes = rootmap->alloc_offset - first_offset + |
| 387 | (last_offset & HAMMER_OFF_LONG_MASK); |
| 388 | } |
| 389 | kprintf("HAMMER(%s) Start redo recovery %016jx - %016jx " |
| 390 | "(%jd bytes of UNDO)%s\n", |
| 391 | root_volume->ondisk->vol_name, |
| 392 | (intmax_t)first_offset, |
| 393 | (intmax_t)last_offset, |
| 394 | (intmax_t)bytes, |
| 395 | (hmp->ronly ? " (RO)" : "(RW)")); |
| 396 | if (bytes > (rootmap->alloc_offset & HAMMER_OFF_LONG_MASK)) { |
| 397 | kprintf("Undo size is absurd, unable to mount\n"); |
| 398 | return(EIO); |
| 399 | } |
| 400 | |
| 401 | /* |
| 402 | * Scan the REDOs forwards. |
| 403 | */ |
| 404 | scan_offset = first_offset; |
| 405 | buffer = NULL; |
| 406 | |
| 407 | while (bytes) { |
| 408 | KKASSERT(scan_offset != last_offset); |
| 409 | |
| 410 | head = hammer_recover_scan_fwd(hmp, root_volume, |
| 411 | &scan_offset, &error, &buffer); |
| 412 | if (error) |
| 413 | break; |
| 414 | |
| 415 | #if 0 |
| 416 | error = hammer_recover_redo(hmp, root_volume, &head->redo); |
| 417 | #endif |
| 418 | if (error) { |
| 419 | kprintf("HAMMER(%s) UNDO record at %016jx failed\n", |
| 420 | root_volume->ondisk->vol_name, |
| 421 | (intmax_t)scan_offset - head->head.hdr_size); |
| 422 | break; |
| 423 | } |
| 424 | bytes -= head->head.hdr_size; |
| 425 | } |
| 426 | if (buffer) { |
| 427 | hammer_rel_buffer(buffer, 0); |
| 428 | buffer = NULL; |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | * Finish up flushing (or discarding) recovered buffers by executing |
| 433 | * a normal flush cycle. Setting HMNT_UNDO_DIRTY bypasses degenerate |
| 434 | * case tests and forces the flush in order to update the FIFO indices. |
| 435 | * |
| 436 | * If a crash occurs during the flush the entire undo/redo will be |
| 437 | * re-run during recovery on the next mount. |
| 438 | */ |
| 439 | if (error == 0) { |
| 440 | if (rootmap->first_offset != rootmap->next_offset) |
| 441 | hmp->hflags |= HMNT_UNDO_DIRTY; |
| 442 | hammer_flusher_sync(hmp); |
| 443 | } |
| 444 | kprintf("HAMMER(%s) End redo recovery\n", |
| 445 | root_volume->ondisk->vol_name); |
| 446 | return (error); |
| 447 | } |
| 448 | |
| 449 | /* |
| 450 | * Scan backwards from *scan_offsetp, return the FIFO record prior to the |
| 451 | * record at *scan_offsetp or NULL if an error occured. |
| 452 | * |
| 453 | * On return *scan_offsetp will be the offset of the returned record. |
| 454 | */ |
| 455 | hammer_fifo_any_t |
| 456 | hammer_recover_scan_rev(hammer_mount_t hmp, hammer_volume_t root_volume, |
| 457 | hammer_off_t *scan_offsetp, |
| 458 | int *errorp, struct hammer_buffer **bufferp) |
| 459 | { |
| 460 | hammer_off_t scan_offset; |
| 461 | hammer_blockmap_t rootmap; |
| 462 | hammer_fifo_any_t head; |
| 463 | hammer_fifo_tail_t tail; |
| 464 | |
| 465 | rootmap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; |
| 466 | scan_offset = *scan_offsetp; |
| 467 | |
| 468 | if (hammer_debug_general & 0x0080) |
| 469 | kprintf("rev scan_offset %016jx\n", (intmax_t)scan_offset); |
| 470 | if (scan_offset == HAMMER_ZONE_ENCODE(HAMMER_ZONE_UNDO_INDEX, 0)) |
| 471 | scan_offset = rootmap->alloc_offset; |
| 472 | if (scan_offset - sizeof(*tail) < |
| 473 | HAMMER_ZONE_ENCODE(HAMMER_ZONE_UNDO_INDEX, 0)) { |
| 474 | kprintf("HAMMER(%s) UNDO record at %016jx FIFO underflow\n", |
| 475 | root_volume->ondisk->vol_name, |
| 476 | (intmax_t)scan_offset); |
| 477 | *errorp = EIO; |
| 478 | return (NULL); |
| 479 | } |
| 480 | tail = hammer_bread(hmp, scan_offset - sizeof(*tail), |
| 481 | errorp, bufferp); |
| 482 | if (*errorp) { |
| 483 | kprintf("HAMMER(%s) Unable to read UNDO TAIL " |
| 484 | "at %016jx\n", |
| 485 | root_volume->ondisk->vol_name, |
| 486 | (intmax_t)scan_offset - sizeof(*tail)); |
| 487 | return (NULL); |
| 488 | } |
| 489 | |
| 490 | if (hammer_check_tail_signature(tail, scan_offset) != 0) { |
| 491 | kprintf("HAMMER(%s) Illegal UNDO TAIL signature " |
| 492 | "at %016jx\n", |
| 493 | root_volume->ondisk->vol_name, |
| 494 | (intmax_t)scan_offset - sizeof(*tail)); |
| 495 | *errorp = EIO; |
| 496 | return (NULL); |
| 497 | } |
| 498 | head = (void *)((char *)tail + sizeof(*tail) - tail->tail_size); |
| 499 | *scan_offsetp = scan_offset - head->head.hdr_size; |
| 500 | |
| 501 | return (head); |
| 502 | } |
| 503 | |
| 504 | /* |
| 505 | * Scan forwards from *scan_offsetp, return the FIFO record or NULL if |
| 506 | * an error occured. |
| 507 | * |
| 508 | * On return *scan_offsetp will be the offset of the record following |
| 509 | * the returned record. |
| 510 | */ |
| 511 | hammer_fifo_any_t |
| 512 | hammer_recover_scan_fwd(hammer_mount_t hmp, hammer_volume_t root_volume, |
| 513 | hammer_off_t *scan_offsetp, |
| 514 | int *errorp, struct hammer_buffer **bufferp) |
| 515 | { |
| 516 | hammer_off_t scan_offset; |
| 517 | hammer_blockmap_t rootmap; |
| 518 | hammer_fifo_any_t head; |
| 519 | |
| 520 | rootmap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX]; |
| 521 | scan_offset = *scan_offsetp; |
| 522 | |
| 523 | if (hammer_debug_general & 0x0080) |
| 524 | kprintf("fwd scan_offset %016jx\n", (intmax_t)scan_offset); |
| 525 | if (scan_offset == rootmap->alloc_offset) |
| 526 | scan_offset = HAMMER_ZONE_ENCODE(HAMMER_ZONE_UNDO_INDEX, 0); |
| 527 | |
| 528 | head = hammer_bread(hmp, scan_offset, errorp, bufferp); |
| 529 | if (*errorp) { |
| 530 | kprintf("HAMMER(%s) Unable to read UNDO HEAD at %016jx\n", |
| 531 | root_volume->ondisk->vol_name, |
| 532 | (intmax_t)scan_offset); |
| 533 | return (NULL); |
| 534 | } |
| 535 | |
| 536 | if (hammer_check_head_signature(&head->head, scan_offset) != 0) { |
| 537 | kprintf("HAMMER(%s) Illegal UNDO TAIL signature " |
| 538 | "at %016jx\n", |
| 539 | root_volume->ondisk->vol_name, |
| 540 | (intmax_t)scan_offset); |
| 541 | *errorp = EIO; |
| 542 | return (NULL); |
| 543 | } |
| 544 | scan_offset += head->head.hdr_size; |
| 545 | if (scan_offset == rootmap->alloc_offset) |
| 546 | scan_offset = HAMMER_ZONE_ENCODE(HAMMER_ZONE_UNDO_INDEX, 0); |
| 547 | *scan_offsetp = scan_offset; |
| 548 | |
| 549 | return (head); |
| 550 | } |
| 551 | |
| 552 | /* |
| 553 | * Helper function for hammer_check_{head,tail}_signature(). Check stuff |
| 554 | * once the head and tail has been established. |
| 555 | * |
| 556 | * This function validates the entire FIFO record wrapper. |
| 557 | */ |
| 558 | static __inline |
| 559 | int |
| 560 | _hammer_check_signature(hammer_fifo_head_t head, hammer_fifo_tail_t tail, |
| 561 | hammer_off_t beg_off) |
| 562 | { |
| 563 | hammer_off_t end_off; |
| 564 | u_int32_t crc; |
| 565 | int bytes; |
| 566 | |
| 567 | /* |
| 568 | * Check signatures. The tail signature is allowed to be the |
| 569 | * head signature only for 8-byte PADs. |
| 570 | */ |
| 571 | if (head->hdr_signature != HAMMER_HEAD_SIGNATURE) { |
| 572 | kprintf("HAMMER: FIFO record bad head signature " |
| 573 | "%04x at %016jx\n", |
| 574 | head->hdr_signature, |
| 575 | (intmax_t)beg_off); |
| 576 | return(2); |
| 577 | } |
| 578 | if (head->hdr_size < HAMMER_HEAD_ALIGN || |
| 579 | (head->hdr_size & HAMMER_HEAD_ALIGN_MASK)) { |
| 580 | kprintf("HAMMER: FIFO record unaligned or bad size" |
| 581 | "%04x at %016jx\n", |
| 582 | head->hdr_size, |
| 583 | (intmax_t)beg_off); |
| 584 | return(2); |
| 585 | } |
| 586 | end_off = beg_off + head->hdr_size; |
| 587 | |
| 588 | if (head->hdr_type != HAMMER_HEAD_TYPE_PAD || |
| 589 | (size_t)(end_off - beg_off) != sizeof(*tail)) { |
| 590 | if (head->hdr_type != tail->tail_type) { |
| 591 | kprintf("HAMMER: FIFO record head/tail type mismatch " |
| 592 | "%04x %04x at %016jx\n", |
| 593 | head->hdr_type, tail->tail_type, |
| 594 | (intmax_t)beg_off); |
| 595 | return(2); |
| 596 | } |
| 597 | if (head->hdr_size != tail->tail_size) { |
| 598 | kprintf("HAMMER: FIFO record head/tail size mismatch " |
| 599 | "%04x %04x at %016jx\n", |
| 600 | head->hdr_size, tail->tail_size, |
| 601 | (intmax_t)beg_off); |
| 602 | return(2); |
| 603 | } |
| 604 | if (tail->tail_signature != HAMMER_TAIL_SIGNATURE) { |
| 605 | kprintf("HAMMER: FIFO record bad tail signature " |
| 606 | "%04x at %016jx\n", |
| 607 | tail->tail_signature, |
| 608 | (intmax_t)beg_off); |
| 609 | return(3); |
| 610 | } |
| 611 | } |
| 612 | |
| 613 | /* |
| 614 | * Non-PAD records must have a CRC and must be sized at |
| 615 | * least large enough to fit the head and tail. |
| 616 | */ |
| 617 | if (head->hdr_type != HAMMER_HEAD_TYPE_PAD) { |
| 618 | crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^ |
| 619 | crc32(head + 1, head->hdr_size - sizeof(*head)); |
| 620 | if (head->hdr_crc != crc) { |
| 621 | kprintf("HAMMER: FIFO record CRC failed %08x %08x " |
| 622 | "at %016jx\n", |
| 623 | head->hdr_crc, crc, |
| 624 | (intmax_t)beg_off); |
| 625 | return(EIO); |
| 626 | } |
| 627 | if (head->hdr_size < sizeof(*head) + sizeof(*tail)) { |
| 628 | kprintf("HAMMER: FIFO record too small " |
| 629 | "%04x at %016jx\n", |
| 630 | head->hdr_size, |
| 631 | (intmax_t)beg_off); |
| 632 | return(EIO); |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | /* |
| 637 | * Check the tail |
| 638 | */ |
| 639 | bytes = head->hdr_size; |
| 640 | tail = (void *)((char *)head + bytes - sizeof(*tail)); |
| 641 | if (tail->tail_size != head->hdr_size) { |
| 642 | kprintf("HAMMER: Bad tail size %04x vs %04x at %016jx\n", |
| 643 | tail->tail_size, head->hdr_size, |
| 644 | (intmax_t)beg_off); |
| 645 | return(EIO); |
| 646 | } |
| 647 | if (tail->tail_type != head->hdr_type) { |
| 648 | kprintf("HAMMER: Bad tail type %04x vs %04x at %016jx\n", |
| 649 | tail->tail_type, head->hdr_type, |
| 650 | (intmax_t)beg_off); |
| 651 | return(EIO); |
| 652 | } |
| 653 | |
| 654 | return(0); |
| 655 | } |
| 656 | |
| 657 | /* |
| 658 | * Check that the FIFO record is in-bounds given the head and the |
| 659 | * hammer offset. |
| 660 | * |
| 661 | * Also checks that the head and tail structures agree with each other, |
| 662 | * but does not check beyond the signature, type, and size. |
| 663 | */ |
| 664 | static int |
| 665 | hammer_check_head_signature(hammer_fifo_head_t head, hammer_off_t beg_off) |
| 666 | { |
| 667 | hammer_fifo_tail_t tail; |
| 668 | hammer_off_t end_off; |
| 669 | |
| 670 | /* |
| 671 | * head overlaps buffer boundary. This could be a PAD so only |
| 672 | * check the minimum PAD size here. |
| 673 | */ |
| 674 | if (((beg_off + sizeof(*tail) - 1) ^ (beg_off)) & ~HAMMER_BUFMASK64) |
| 675 | return(1); |
| 676 | |
| 677 | /* |
| 678 | * Calculate the ending offset and make sure the record does |
| 679 | * not cross a buffer boundary. |
| 680 | */ |
| 681 | end_off = beg_off + head->hdr_size; |
| 682 | if ((beg_off ^ (end_off - 1)) & ~HAMMER_BUFMASK64) |
| 683 | return(1); |
| 684 | tail = (void *)((char *)head + head->hdr_size - sizeof(*tail)); |
| 685 | return (_hammer_check_signature(head, tail, beg_off)); |
| 686 | } |
| 687 | |
| 688 | /* |
| 689 | * Check that the FIFO record is in-bounds given the tail and the |
| 690 | * hammer offset. The offset is pointing at the ending boundary of the |
| 691 | * record. |
| 692 | * |
| 693 | * Also checks that the head and tail structures agree with each other, |
| 694 | * but does not check beyond the signature, type, and size. |
| 695 | */ |
| 696 | static int |
| 697 | hammer_check_tail_signature(hammer_fifo_tail_t tail, hammer_off_t end_off) |
| 698 | { |
| 699 | hammer_fifo_head_t head; |
| 700 | hammer_off_t beg_off; |
| 701 | |
| 702 | /* |
| 703 | * tail overlaps buffer boundary |
| 704 | */ |
| 705 | if (((end_off - sizeof(*tail)) ^ (end_off - 1)) & ~HAMMER_BUFMASK64) |
| 706 | return(1); |
| 707 | |
| 708 | /* |
| 709 | * Calculate the begining offset and make sure the record does |
| 710 | * not cross a buffer boundary. |
| 711 | */ |
| 712 | beg_off = end_off - tail->tail_size; |
| 713 | if ((beg_off ^ (end_off - 1)) & ~HAMMER_BUFMASK64) |
| 714 | return(1); |
| 715 | head = (void *)((char *)tail + sizeof(*tail) - tail->tail_size); |
| 716 | return (_hammer_check_signature(head, tail, beg_off)); |
| 717 | } |
| 718 | |
| 719 | static int |
| 720 | hammer_recover_undo(hammer_mount_t hmp, hammer_volume_t root_volume, |
| 721 | hammer_fifo_undo_t undo) |
| 722 | { |
| 723 | hammer_volume_t volume; |
| 724 | hammer_buffer_t buffer; |
| 725 | hammer_off_t buf_offset; |
| 726 | int zone; |
| 727 | int error; |
| 728 | int vol_no; |
| 729 | int bytes; |
| 730 | u_int32_t offset; |
| 731 | |
| 732 | /* |
| 733 | * Only process UNDO records. Flag if we find other records to |
| 734 | * optimize stage2 recovery. |
| 735 | */ |
| 736 | if (undo->head.hdr_type != HAMMER_HEAD_TYPE_UNDO) { |
| 737 | if (undo->head.hdr_type == HAMMER_HEAD_TYPE_REDO) |
| 738 | hmp->hflags |= HMNT_HASREDO; |
| 739 | return(0); |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Validate the UNDO record. |
| 744 | */ |
| 745 | bytes = undo->head.hdr_size - sizeof(*undo) - |
| 746 | sizeof(struct hammer_fifo_tail); |
| 747 | if (bytes < 0 || undo->undo_data_bytes < 0 || |
| 748 | undo->undo_data_bytes > bytes) { |
| 749 | kprintf("HAMMER: Corrupt UNDO record, undo_data_bytes %d/%d\n", |
| 750 | undo->undo_data_bytes, bytes); |
| 751 | return(EIO); |
| 752 | } |
| 753 | |
| 754 | bytes = undo->undo_data_bytes; |
| 755 | |
| 756 | /* |
| 757 | * The undo offset may only be a zone-1 or zone-2 offset. |
| 758 | * |
| 759 | * Currently we only support a zone-1 offset representing the |
| 760 | * volume header. |
| 761 | */ |
| 762 | zone = HAMMER_ZONE_DECODE(undo->undo_offset); |
| 763 | offset = undo->undo_offset & HAMMER_BUFMASK; |
| 764 | |
| 765 | if (offset + bytes > HAMMER_BUFSIZE) { |
| 766 | kprintf("HAMMER: Corrupt UNDO record, bad offset\n"); |
| 767 | return (EIO); |
| 768 | } |
| 769 | |
| 770 | switch(zone) { |
| 771 | case HAMMER_ZONE_RAW_VOLUME_INDEX: |
| 772 | vol_no = HAMMER_VOL_DECODE(undo->undo_offset); |
| 773 | volume = hammer_get_volume(hmp, vol_no, &error); |
| 774 | if (volume == NULL) { |
| 775 | kprintf("HAMMER: UNDO record, " |
| 776 | "cannot access volume %d\n", vol_no); |
| 777 | break; |
| 778 | } |
| 779 | hammer_modify_volume(NULL, volume, NULL, 0); |
| 780 | hammer_recover_copy_undo(undo->undo_offset, |
| 781 | (char *)(undo + 1), |
| 782 | (char *)volume->ondisk + offset, |
| 783 | bytes); |
| 784 | hammer_modify_volume_done(volume); |
| 785 | |
| 786 | /* |
| 787 | * Multiple modifications may be made to the same buffer. |
| 788 | * Also, the volume header cannot be written out until |
| 789 | * everything else has been flushed. This also |
| 790 | * covers the read-only case by preventing the kernel from |
| 791 | * flushing the buffer. |
| 792 | */ |
| 793 | if (volume->io.recovered == 0) |
| 794 | volume->io.recovered = 1; |
| 795 | else |
| 796 | hammer_rel_volume(volume, 0); |
| 797 | break; |
| 798 | case HAMMER_ZONE_RAW_BUFFER_INDEX: |
| 799 | buf_offset = undo->undo_offset & ~HAMMER_BUFMASK64; |
| 800 | buffer = hammer_get_buffer(hmp, buf_offset, HAMMER_BUFSIZE, |
| 801 | 0, &error); |
| 802 | if (buffer == NULL) { |
| 803 | kprintf("HAMMER: UNDO record, " |
| 804 | "cannot access buffer %016jx\n", |
| 805 | (intmax_t)undo->undo_offset); |
| 806 | break; |
| 807 | } |
| 808 | hammer_modify_buffer(NULL, buffer, NULL, 0); |
| 809 | hammer_recover_copy_undo(undo->undo_offset, |
| 810 | (char *)(undo + 1), |
| 811 | (char *)buffer->ondisk + offset, |
| 812 | bytes); |
| 813 | hammer_modify_buffer_done(buffer); |
| 814 | |
| 815 | /* |
| 816 | * Multiple modifications may be made to the same buffer, |
| 817 | * improve performance by delaying the flush. This also |
| 818 | * covers the read-only case by preventing the kernel from |
| 819 | * flushing the buffer. |
| 820 | */ |
| 821 | if (buffer->io.recovered == 0) |
| 822 | buffer->io.recovered = 1; |
| 823 | else |
| 824 | hammer_rel_buffer(buffer, 0); |
| 825 | break; |
| 826 | default: |
| 827 | kprintf("HAMMER: Corrupt UNDO record\n"); |
| 828 | error = EIO; |
| 829 | } |
| 830 | return (error); |
| 831 | } |
| 832 | |
| 833 | static void |
| 834 | hammer_recover_copy_undo(hammer_off_t undo_offset, |
| 835 | char *src, char *dst, int bytes) |
| 836 | { |
| 837 | if (hammer_debug_general & 0x0080) { |
| 838 | kprintf("UNDO %016jx: %d\n", |
| 839 | (intmax_t)undo_offset, bytes); |
| 840 | } |
| 841 | #if 0 |
| 842 | kprintf("UNDO %016jx:", (intmax_t)undo_offset); |
| 843 | hammer_recover_debug_dump(22, dst, bytes); |
| 844 | kprintf("%22s", "to:"); |
| 845 | hammer_recover_debug_dump(22, src, bytes); |
| 846 | #endif |
| 847 | bcopy(src, dst, bytes); |
| 848 | } |
| 849 | |
| 850 | #if 0 |
| 851 | |
| 852 | static void |
| 853 | hammer_recover_debug_dump(int w, char *buf, int bytes) |
| 854 | { |
| 855 | int i; |
| 856 | |
| 857 | for (i = 0; i < bytes; ++i) { |
| 858 | if (i && (i & 15) == 0) |
| 859 | kprintf("\n%*.*s", w, w, ""); |
| 860 | kprintf(" %02x", (unsigned char)buf[i]); |
| 861 | } |
| 862 | kprintf("\n"); |
| 863 | } |
| 864 | |
| 865 | #endif |
| 866 | |
| 867 | /* |
| 868 | * Flush recovered buffers from recovery operations. The call to this |
| 869 | * routine may be delayed if a read-only mount was made and then later |
| 870 | * upgraded to read-write. This routine is also called when unmounting |
| 871 | * a read-only mount to clean out recovered (dirty) buffers which we |
| 872 | * couldn't flush (because the mount is read-only). |
| 873 | * |
| 874 | * The volume header is always written last. The UNDO FIFO will be forced |
| 875 | * to zero-length by setting next_offset to first_offset. This leaves the |
| 876 | * (now stale) UNDO information used to recover the disk available for |
| 877 | * forensic analysis. |
| 878 | * |
| 879 | * final is typically 0 or 1. The volume header is only written if final |
| 880 | * is 1. If final is -1 the recovered buffers are discarded instead of |
| 881 | * written and root_volume can also be passed as NULL in that case. |
| 882 | */ |
| 883 | static int hammer_recover_flush_volume_callback(hammer_volume_t, void *); |
| 884 | static int hammer_recover_flush_buffer_callback(hammer_buffer_t, void *); |
| 885 | |
| 886 | void |
| 887 | hammer_recover_flush_buffers(hammer_mount_t hmp, hammer_volume_t root_volume, |
| 888 | int final) |
| 889 | { |
| 890 | /* |
| 891 | * Flush the buffers out asynchronously, wait for all the I/O to |
| 892 | * complete, then do it again to destroy the buffer cache buffer |
| 893 | * so it doesn't alias something later on. |
| 894 | */ |
| 895 | RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL, |
| 896 | hammer_recover_flush_buffer_callback, &final); |
| 897 | hammer_io_wait_all(hmp, "hmrrcw"); |
| 898 | RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL, |
| 899 | hammer_recover_flush_buffer_callback, &final); |
| 900 | |
| 901 | /* |
| 902 | * Flush all volume headers except the root volume. If final < 0 |
| 903 | * we discard all volume headers including the root volume. |
| 904 | */ |
| 905 | if (final >= 0) { |
| 906 | RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL, |
| 907 | hammer_recover_flush_volume_callback, root_volume); |
| 908 | } else { |
| 909 | RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL, |
| 910 | hammer_recover_flush_volume_callback, NULL); |
| 911 | } |
| 912 | |
| 913 | /* |
| 914 | * Finalize the root volume header. |
| 915 | */ |
| 916 | if (root_volume && root_volume->io.recovered && final > 0) { |
| 917 | crit_enter(); |
| 918 | while (hmp->io_running_space > 0) |
| 919 | tsleep(&hmp->io_running_space, 0, "hmrflx", 0); |
| 920 | crit_exit(); |
| 921 | root_volume->io.recovered = 0; |
| 922 | hammer_io_flush(&root_volume->io, 0); |
| 923 | hammer_rel_volume(root_volume, 0); |
| 924 | } |
| 925 | } |
| 926 | |
| 927 | /* |
| 928 | * Callback to flush volume headers. If discarding data will be NULL and |
| 929 | * all volume headers (including the root volume) will be discarded. |
| 930 | * Otherwise data is the root_volume and we flush all volume headers |
| 931 | * EXCEPT the root_volume. |
| 932 | * |
| 933 | * Clear any I/O error or modified condition when discarding buffers to |
| 934 | * clean up the reference count, otherwise the buffer may have extra refs |
| 935 | * on it. |
| 936 | */ |
| 937 | static |
| 938 | int |
| 939 | hammer_recover_flush_volume_callback(hammer_volume_t volume, void *data) |
| 940 | { |
| 941 | hammer_volume_t root_volume = data; |
| 942 | |
| 943 | if (volume->io.recovered && volume != root_volume) { |
| 944 | volume->io.recovered = 0; |
| 945 | if (root_volume != NULL) { |
| 946 | hammer_io_flush(&volume->io, 0); |
| 947 | } else { |
| 948 | hammer_io_clear_error(&volume->io); |
| 949 | hammer_io_clear_modify(&volume->io, 1); |
| 950 | } |
| 951 | hammer_rel_volume(volume, 0); |
| 952 | } |
| 953 | return(0); |
| 954 | } |
| 955 | |
| 956 | /* |
| 957 | * Flush or discard recovered I/O buffers. |
| 958 | * |
| 959 | * Clear any I/O error or modified condition when discarding buffers to |
| 960 | * clean up the reference count, otherwise the buffer may have extra refs |
| 961 | * on it. |
| 962 | */ |
| 963 | static |
| 964 | int |
| 965 | hammer_recover_flush_buffer_callback(hammer_buffer_t buffer, void *data) |
| 966 | { |
| 967 | int final = *(int *)data; |
| 968 | |
| 969 | if (buffer->io.recovered) { |
| 970 | buffer->io.recovered = 0; |
| 971 | buffer->io.reclaim = 1; |
| 972 | if (final < 0) { |
| 973 | hammer_io_clear_error(&buffer->io); |
| 974 | hammer_io_clear_modify(&buffer->io, 1); |
| 975 | } else { |
| 976 | hammer_io_flush(&buffer->io, 0); |
| 977 | } |
| 978 | hammer_rel_buffer(buffer, 0); |
| 979 | } else { |
| 980 | if (buffer->io.lock.refs == 0) |
| 981 | ++hammer_count_refedbufs; |
| 982 | hammer_ref(&buffer->io.lock); |
| 983 | if (final < 0) { |
| 984 | hammer_io_clear_error(&buffer->io); |
| 985 | hammer_io_clear_modify(&buffer->io, 1); |
| 986 | } |
| 987 | KKASSERT(buffer->io.lock.refs == 1); |
| 988 | buffer->io.reclaim = 1; |
| 989 | hammer_rel_buffer(buffer, 1); |
| 990 | } |
| 991 | return(0); |
| 992 | } |
| 993 | |