| 1 | /* |
| 2 | * Copyright (c) 2004-2006 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/kern/vfs_journal.c,v 1.33 2007/05/09 00:53:34 dillon Exp $ |
| 35 | */ |
| 36 | /* |
| 37 | * The journaling protocol is intended to evolve into a two-way stream |
| 38 | * whereby transaction IDs can be acknowledged by the journaling target |
| 39 | * when the data has been committed to hard storage. Both implicit and |
| 40 | * explicit acknowledgement schemes will be supported, depending on the |
| 41 | * sophistication of the journaling stream, plus resynchronization and |
| 42 | * restart when a journaling stream is interrupted. This information will |
| 43 | * also be made available to journaling-aware filesystems to allow better |
| 44 | * management of their own physical storage synchronization mechanisms as |
| 45 | * well as to allow such filesystems to take direct advantage of the kernel's |
| 46 | * journaling layer so they don't have to roll their own. |
| 47 | * |
| 48 | * In addition, the worker thread will have access to much larger |
| 49 | * spooling areas then the memory buffer is able to provide by e.g. |
| 50 | * reserving swap space, in order to absorb potentially long interruptions |
| 51 | * of off-site journaling streams, and to prevent 'slow' off-site linkages |
| 52 | * from radically slowing down local filesystem operations. |
| 53 | * |
| 54 | * Because of the non-trivial algorithms the journaling system will be |
| 55 | * required to support, use of a worker thread is mandatory. Efficiencies |
| 56 | * are maintained by utilitizing the memory FIFO to batch transactions when |
| 57 | * possible, reducing the number of gratuitous thread switches and taking |
| 58 | * advantage of cpu caches through the use of shorter batched code paths |
| 59 | * rather then trying to do everything in the context of the process |
| 60 | * originating the filesystem op. In the future the memory FIFO can be |
| 61 | * made per-cpu to remove BGL or other locking requirements. |
| 62 | */ |
| 63 | #include <sys/param.h> |
| 64 | #include <sys/systm.h> |
| 65 | #include <sys/buf.h> |
| 66 | #include <sys/conf.h> |
| 67 | #include <sys/kernel.h> |
| 68 | #include <sys/queue.h> |
| 69 | #include <sys/lock.h> |
| 70 | #include <sys/malloc.h> |
| 71 | #include <sys/mount.h> |
| 72 | #include <sys/unistd.h> |
| 73 | #include <sys/vnode.h> |
| 74 | #include <sys/poll.h> |
| 75 | #include <sys/mountctl.h> |
| 76 | #include <sys/journal.h> |
| 77 | #include <sys/file.h> |
| 78 | #include <sys/proc.h> |
| 79 | #include <sys/msfbuf.h> |
| 80 | #include <sys/socket.h> |
| 81 | #include <sys/socketvar.h> |
| 82 | |
| 83 | #include <machine/limits.h> |
| 84 | |
| 85 | #include <vm/vm.h> |
| 86 | #include <vm/vm_object.h> |
| 87 | #include <vm/vm_page.h> |
| 88 | #include <vm/vm_pager.h> |
| 89 | #include <vm/vnode_pager.h> |
| 90 | |
| 91 | #include <sys/file2.h> |
| 92 | #include <sys/thread2.h> |
| 93 | #include <sys/spinlock2.h> |
| 94 | |
| 95 | static void journal_wthread(void *info); |
| 96 | static void journal_rthread(void *info); |
| 97 | |
| 98 | static void *journal_reserve(struct journal *jo, |
| 99 | struct journal_rawrecbeg **rawpp, |
| 100 | int16_t streamid, int bytes); |
| 101 | static void *journal_extend(struct journal *jo, |
| 102 | struct journal_rawrecbeg **rawpp, |
| 103 | int truncbytes, int bytes, int *newstreamrecp); |
| 104 | static void journal_abort(struct journal *jo, |
| 105 | struct journal_rawrecbeg **rawpp); |
| 106 | static void journal_commit(struct journal *jo, |
| 107 | struct journal_rawrecbeg **rawpp, |
| 108 | int bytes, int closeout); |
| 109 | |
| 110 | |
| 111 | MALLOC_DEFINE(M_JOURNAL, "journal", "Journaling structures"); |
| 112 | MALLOC_DEFINE(M_JFIFO, "journal-fifo", "Journal FIFO"); |
| 113 | |
| 114 | void |
| 115 | journal_create_threads(struct journal *jo) |
| 116 | { |
| 117 | jo->flags &= ~(MC_JOURNAL_STOP_REQ | MC_JOURNAL_STOP_IMM); |
| 118 | jo->flags |= MC_JOURNAL_WACTIVE; |
| 119 | lwkt_create(journal_wthread, jo, NULL, &jo->wthread, |
| 120 | TDF_STOPREQ, -1, "journal w:%.*s", JIDMAX, jo->id); |
| 121 | lwkt_setpri(&jo->wthread, TDPRI_KERN_DAEMON); |
| 122 | lwkt_schedule(&jo->wthread); |
| 123 | |
| 124 | if (jo->flags & MC_JOURNAL_WANT_FULLDUPLEX) { |
| 125 | jo->flags |= MC_JOURNAL_RACTIVE; |
| 126 | lwkt_create(journal_rthread, jo, NULL, &jo->rthread, |
| 127 | TDF_STOPREQ, -1, "journal r:%.*s", JIDMAX, jo->id); |
| 128 | lwkt_setpri(&jo->rthread, TDPRI_KERN_DAEMON); |
| 129 | lwkt_schedule(&jo->rthread); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | void |
| 134 | journal_destroy_threads(struct journal *jo, int flags) |
| 135 | { |
| 136 | int wcount; |
| 137 | |
| 138 | jo->flags |= MC_JOURNAL_STOP_REQ | (flags & MC_JOURNAL_STOP_IMM); |
| 139 | wakeup(&jo->fifo); |
| 140 | wcount = 0; |
| 141 | while (jo->flags & (MC_JOURNAL_WACTIVE | MC_JOURNAL_RACTIVE)) { |
| 142 | tsleep(jo, 0, "jwait", hz); |
| 143 | if (++wcount % 10 == 0) { |
| 144 | kprintf("Warning: journal %s waiting for descriptors to close\n", |
| 145 | jo->id); |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | /* |
| 150 | * XXX SMP - threads should move to cpu requesting the restart or |
| 151 | * termination before finishing up to properly interlock. |
| 152 | */ |
| 153 | tsleep(jo, 0, "jwait", hz); |
| 154 | lwkt_free_thread(&jo->wthread); |
| 155 | if (jo->flags & MC_JOURNAL_WANT_FULLDUPLEX) |
| 156 | lwkt_free_thread(&jo->rthread); |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * The per-journal worker thread is responsible for writing out the |
| 161 | * journal's FIFO to the target stream. |
| 162 | */ |
| 163 | static void |
| 164 | journal_wthread(void *info) |
| 165 | { |
| 166 | struct journal *jo = info; |
| 167 | struct journal_rawrecbeg *rawp; |
| 168 | int error; |
| 169 | size_t avail; |
| 170 | size_t bytes; |
| 171 | size_t res; |
| 172 | |
| 173 | for (;;) { |
| 174 | /* |
| 175 | * Calculate the number of bytes available to write. This buffer |
| 176 | * area may contain reserved records so we can't just write it out |
| 177 | * without further checks. |
| 178 | */ |
| 179 | bytes = jo->fifo.windex - jo->fifo.rindex; |
| 180 | |
| 181 | /* |
| 182 | * sleep if no bytes are available or if an incomplete record is |
| 183 | * encountered (it needs to be filled in before we can write it |
| 184 | * out), and skip any pad records that we encounter. |
| 185 | */ |
| 186 | if (bytes == 0) { |
| 187 | if (jo->flags & MC_JOURNAL_STOP_REQ) |
| 188 | break; |
| 189 | tsleep(&jo->fifo, 0, "jfifo", hz); |
| 190 | continue; |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Sleep if we can not go any further due to hitting an incomplete |
| 195 | * record. This case should occur rarely but may have to be better |
| 196 | * optimized XXX. |
| 197 | */ |
| 198 | rawp = (void *)(jo->fifo.membase + (jo->fifo.rindex & jo->fifo.mask)); |
| 199 | if (rawp->begmagic == JREC_INCOMPLETEMAGIC) { |
| 200 | tsleep(&jo->fifo, 0, "jpad", hz); |
| 201 | continue; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * Skip any pad records. We do not write out pad records if we can |
| 206 | * help it. |
| 207 | */ |
| 208 | if (rawp->streamid == JREC_STREAMID_PAD) { |
| 209 | if ((jo->flags & MC_JOURNAL_WANT_FULLDUPLEX) == 0) { |
| 210 | if (jo->fifo.rindex == jo->fifo.xindex) { |
| 211 | jo->fifo.xindex += (rawp->recsize + 15) & ~15; |
| 212 | jo->total_acked += (rawp->recsize + 15) & ~15; |
| 213 | } |
| 214 | } |
| 215 | jo->fifo.rindex += (rawp->recsize + 15) & ~15; |
| 216 | jo->total_acked += bytes; |
| 217 | KKASSERT(jo->fifo.windex - jo->fifo.rindex >= 0); |
| 218 | continue; |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | * 'bytes' is the amount of data that can potentially be written out. |
| 223 | * Calculate 'res', the amount of data that can actually be written |
| 224 | * out. res is bounded either by hitting the end of the physical |
| 225 | * memory buffer or by hitting an incomplete record. Incomplete |
| 226 | * records often occur due to the way the space reservation model |
| 227 | * works. |
| 228 | */ |
| 229 | res = 0; |
| 230 | avail = jo->fifo.size - (jo->fifo.rindex & jo->fifo.mask); |
| 231 | while (res < bytes && rawp->begmagic == JREC_BEGMAGIC) { |
| 232 | res += (rawp->recsize + 15) & ~15; |
| 233 | if (res >= avail) { |
| 234 | KKASSERT(res == avail); |
| 235 | break; |
| 236 | } |
| 237 | rawp = (void *)((char *)rawp + ((rawp->recsize + 15) & ~15)); |
| 238 | } |
| 239 | |
| 240 | /* |
| 241 | * Issue the write and deal with any errors or other conditions. |
| 242 | * For now assume blocking I/O. Since we are record-aware the |
| 243 | * code cannot yet handle partial writes. |
| 244 | * |
| 245 | * We bump rindex prior to issuing the write to avoid racing |
| 246 | * the acknowledgement coming back (which could prevent the ack |
| 247 | * from bumping xindex). Restarts are always based on xindex so |
| 248 | * we do not try to undo the rindex if an error occurs. |
| 249 | * |
| 250 | * XXX EWOULDBLOCK/NBIO |
| 251 | * XXX notification on failure |
| 252 | * XXX permanent verses temporary failures |
| 253 | * XXX two-way acknowledgement stream in the return direction / xindex |
| 254 | */ |
| 255 | bytes = res; |
| 256 | jo->fifo.rindex += bytes; |
| 257 | error = fp_write(jo->fp, |
| 258 | jo->fifo.membase + |
| 259 | ((jo->fifo.rindex - bytes) & jo->fifo.mask), |
| 260 | bytes, &res, UIO_SYSSPACE); |
| 261 | if (error) { |
| 262 | kprintf("journal_thread(%s) write, error %d\n", jo->id, error); |
| 263 | /* XXX */ |
| 264 | } else { |
| 265 | KKASSERT(res == bytes); |
| 266 | } |
| 267 | |
| 268 | /* |
| 269 | * Advance rindex. If the journal stream is not full duplex we also |
| 270 | * advance xindex, otherwise the rjournal thread is responsible for |
| 271 | * advancing xindex. |
| 272 | */ |
| 273 | if ((jo->flags & MC_JOURNAL_WANT_FULLDUPLEX) == 0) { |
| 274 | jo->fifo.xindex += bytes; |
| 275 | jo->total_acked += bytes; |
| 276 | } |
| 277 | KKASSERT(jo->fifo.windex - jo->fifo.rindex >= 0); |
| 278 | if ((jo->flags & MC_JOURNAL_WANT_FULLDUPLEX) == 0) { |
| 279 | if (jo->flags & MC_JOURNAL_WWAIT) { |
| 280 | jo->flags &= ~MC_JOURNAL_WWAIT; /* XXX hysteresis */ |
| 281 | wakeup(&jo->fifo.windex); |
| 282 | } |
| 283 | } |
| 284 | } |
| 285 | fp_shutdown(jo->fp, SHUT_WR); |
| 286 | jo->flags &= ~MC_JOURNAL_WACTIVE; |
| 287 | wakeup(jo); |
| 288 | wakeup(&jo->fifo.windex); |
| 289 | } |
| 290 | |
| 291 | /* |
| 292 | * A second per-journal worker thread is created for two-way journaling |
| 293 | * streams to deal with the return acknowledgement stream. |
| 294 | */ |
| 295 | static void |
| 296 | journal_rthread(void *info) |
| 297 | { |
| 298 | struct journal_rawrecbeg *rawp; |
| 299 | struct journal_ackrecord ack; |
| 300 | struct journal *jo = info; |
| 301 | int64_t transid; |
| 302 | int error; |
| 303 | size_t count; |
| 304 | size_t bytes; |
| 305 | |
| 306 | transid = 0; |
| 307 | error = 0; |
| 308 | |
| 309 | for (;;) { |
| 310 | /* |
| 311 | * We have been asked to stop |
| 312 | */ |
| 313 | if (jo->flags & MC_JOURNAL_STOP_REQ) |
| 314 | break; |
| 315 | |
| 316 | /* |
| 317 | * If we have no active transaction id, get one from the return |
| 318 | * stream. |
| 319 | */ |
| 320 | if (transid == 0) { |
| 321 | error = fp_read(jo->fp, &ack, sizeof(ack), &count, |
| 322 | 1, UIO_SYSSPACE); |
| 323 | #if 0 |
| 324 | kprintf("fp_read ack error %d count %d\n", error, count); |
| 325 | #endif |
| 326 | if (error || count != sizeof(ack)) |
| 327 | break; |
| 328 | if (error) { |
| 329 | kprintf("read error %d on receive stream\n", error); |
| 330 | break; |
| 331 | } |
| 332 | if (ack.rbeg.begmagic != JREC_BEGMAGIC || |
| 333 | ack.rend.endmagic != JREC_ENDMAGIC |
| 334 | ) { |
| 335 | kprintf("bad begmagic or endmagic on receive stream\n"); |
| 336 | break; |
| 337 | } |
| 338 | transid = ack.rbeg.transid; |
| 339 | } |
| 340 | |
| 341 | /* |
| 342 | * Calculate the number of unacknowledged bytes. If there are no |
| 343 | * unacknowledged bytes then unsent data was acknowledged, report, |
| 344 | * sleep a bit, and loop in that case. This should not happen |
| 345 | * normally. The ack record is thrown away. |
| 346 | */ |
| 347 | bytes = jo->fifo.rindex - jo->fifo.xindex; |
| 348 | |
| 349 | if (bytes == 0) { |
| 350 | kprintf("warning: unsent data acknowledged transid %08llx\n", |
| 351 | (long long)transid); |
| 352 | tsleep(&jo->fifo.xindex, 0, "jrseq", hz); |
| 353 | transid = 0; |
| 354 | continue; |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Since rindex has advanced, the record pointed to by xindex |
| 359 | * must be a valid record. |
| 360 | */ |
| 361 | rawp = (void *)(jo->fifo.membase + (jo->fifo.xindex & jo->fifo.mask)); |
| 362 | KKASSERT(rawp->begmagic == JREC_BEGMAGIC); |
| 363 | KKASSERT(rawp->recsize <= bytes); |
| 364 | |
| 365 | /* |
| 366 | * The target can acknowledge several records at once. |
| 367 | */ |
| 368 | if (rawp->transid < transid) { |
| 369 | #if 1 |
| 370 | kprintf("ackskip %08llx/%08llx\n", |
| 371 | (long long)rawp->transid, |
| 372 | (long long)transid); |
| 373 | #endif |
| 374 | jo->fifo.xindex += (rawp->recsize + 15) & ~15; |
| 375 | jo->total_acked += (rawp->recsize + 15) & ~15; |
| 376 | if (jo->flags & MC_JOURNAL_WWAIT) { |
| 377 | jo->flags &= ~MC_JOURNAL_WWAIT; /* XXX hysteresis */ |
| 378 | wakeup(&jo->fifo.windex); |
| 379 | } |
| 380 | continue; |
| 381 | } |
| 382 | if (rawp->transid == transid) { |
| 383 | #if 1 |
| 384 | kprintf("ackskip %08llx/%08llx\n", |
| 385 | (long long)rawp->transid, |
| 386 | (long long)transid); |
| 387 | #endif |
| 388 | jo->fifo.xindex += (rawp->recsize + 15) & ~15; |
| 389 | jo->total_acked += (rawp->recsize + 15) & ~15; |
| 390 | if (jo->flags & MC_JOURNAL_WWAIT) { |
| 391 | jo->flags &= ~MC_JOURNAL_WWAIT; /* XXX hysteresis */ |
| 392 | wakeup(&jo->fifo.windex); |
| 393 | } |
| 394 | transid = 0; |
| 395 | continue; |
| 396 | } |
| 397 | kprintf("warning: unsent data(2) acknowledged transid %08llx\n", |
| 398 | (long long)transid); |
| 399 | transid = 0; |
| 400 | } |
| 401 | jo->flags &= ~MC_JOURNAL_RACTIVE; |
| 402 | wakeup(jo); |
| 403 | wakeup(&jo->fifo.windex); |
| 404 | } |
| 405 | |
| 406 | /* |
| 407 | * This builds a pad record which the journaling thread will skip over. Pad |
| 408 | * records are required when we are unable to reserve sufficient stream space |
| 409 | * due to insufficient space at the end of the physical memory fifo. |
| 410 | * |
| 411 | * Even though the record is not transmitted, a normal transid must be |
| 412 | * assigned to it so link recovery operations after a failure work properly. |
| 413 | */ |
| 414 | static |
| 415 | void |
| 416 | journal_build_pad(struct journal_rawrecbeg *rawp, int recsize, int64_t transid) |
| 417 | { |
| 418 | struct journal_rawrecend *rendp; |
| 419 | |
| 420 | KKASSERT((recsize & 15) == 0 && recsize >= 16); |
| 421 | |
| 422 | rawp->streamid = JREC_STREAMID_PAD; |
| 423 | rawp->recsize = recsize; /* must be 16-byte aligned */ |
| 424 | rawp->transid = transid; |
| 425 | /* |
| 426 | * WARNING, rendp may overlap rawp->transid. This is necessary to |
| 427 | * allow PAD records to fit in 16 bytes. Use cpu_ccfence() to |
| 428 | * hopefully cause the compiler to not make any assumptions. |
| 429 | */ |
| 430 | rendp = (void *)((char *)rawp + rawp->recsize - sizeof(*rendp)); |
| 431 | rendp->endmagic = JREC_ENDMAGIC; |
| 432 | rendp->check = 0; |
| 433 | rendp->recsize = rawp->recsize; |
| 434 | |
| 435 | /* |
| 436 | * Set the begin magic last. This is what will allow the journal |
| 437 | * thread to write the record out. Use a store fence to prevent |
| 438 | * compiler and cpu reordering of the writes. |
| 439 | */ |
| 440 | cpu_sfence(); |
| 441 | rawp->begmagic = JREC_BEGMAGIC; |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * Wake up the worker thread if the FIFO is more then half full or if |
| 446 | * someone is waiting for space to be freed up. Otherwise let the |
| 447 | * heartbeat deal with it. Being able to avoid waking up the worker |
| 448 | * is the key to the journal's cpu performance. |
| 449 | */ |
| 450 | static __inline |
| 451 | void |
| 452 | journal_commit_wakeup(struct journal *jo) |
| 453 | { |
| 454 | int avail; |
| 455 | |
| 456 | avail = jo->fifo.size - (jo->fifo.windex - jo->fifo.xindex); |
| 457 | KKASSERT(avail >= 0); |
| 458 | if ((avail < (jo->fifo.size >> 1)) || (jo->flags & MC_JOURNAL_WWAIT)) |
| 459 | wakeup(&jo->fifo); |
| 460 | } |
| 461 | |
| 462 | /* |
| 463 | * Create a new BEGIN stream record with the specified streamid and the |
| 464 | * specified amount of payload space. *rawpp will be set to point to the |
| 465 | * base of the new stream record and a pointer to the base of the payload |
| 466 | * space will be returned. *rawpp does not need to be pre-NULLd prior to |
| 467 | * making this call. The raw record header will be partially initialized. |
| 468 | * |
| 469 | * A stream can be extended, aborted, or committed by other API calls |
| 470 | * below. This may result in a sequence of potentially disconnected |
| 471 | * stream records to be output to the journaling target. The first record |
| 472 | * (the one created by this function) will be marked JREC_STREAMCTL_BEGIN, |
| 473 | * while the last record on commit or abort will be marked JREC_STREAMCTL_END |
| 474 | * (and possibly also JREC_STREAMCTL_ABORTED). The last record could wind |
| 475 | * up being the same as the first, in which case the bits are all set in |
| 476 | * the first record. |
| 477 | * |
| 478 | * The stream record is created in an incomplete state by setting the begin |
| 479 | * magic to JREC_INCOMPLETEMAGIC. This prevents the worker thread from |
| 480 | * flushing the fifo past our record until we have finished populating it. |
| 481 | * Other threads can reserve and operate on their own space without stalling |
| 482 | * but the stream output will stall until we have completed operations. The |
| 483 | * memory FIFO is intended to be large enough to absorb such situations |
| 484 | * without stalling out other threads. |
| 485 | */ |
| 486 | static |
| 487 | void * |
| 488 | journal_reserve(struct journal *jo, struct journal_rawrecbeg **rawpp, |
| 489 | int16_t streamid, int bytes) |
| 490 | { |
| 491 | struct journal_rawrecbeg *rawp; |
| 492 | int avail; |
| 493 | int availtoend; |
| 494 | int req; |
| 495 | |
| 496 | /* |
| 497 | * Add header and trailer overheads to the passed payload. Note that |
| 498 | * the passed payload size need not be aligned in any way. |
| 499 | */ |
| 500 | bytes += sizeof(struct journal_rawrecbeg); |
| 501 | bytes += sizeof(struct journal_rawrecend); |
| 502 | |
| 503 | for (;;) { |
| 504 | /* |
| 505 | * First, check boundary conditions. If the request would wrap around |
| 506 | * we have to skip past the ending block and return to the beginning |
| 507 | * of the FIFO's buffer. Calculate 'req' which is the actual number |
| 508 | * of bytes being reserved, including wrap-around dead space. |
| 509 | * |
| 510 | * Neither 'bytes' or 'req' are aligned. |
| 511 | * |
| 512 | * Note that availtoend is not truncated to avail and so cannot be |
| 513 | * used to determine whether the reservation is possible by itself. |
| 514 | * Also, since all fifo ops are 16-byte aligned, we can check |
| 515 | * the size before calculating the aligned size. |
| 516 | */ |
| 517 | availtoend = jo->fifo.size - (jo->fifo.windex & jo->fifo.mask); |
| 518 | KKASSERT((availtoend & 15) == 0); |
| 519 | if (bytes > availtoend) |
| 520 | req = bytes + availtoend; /* add pad to end */ |
| 521 | else |
| 522 | req = bytes; |
| 523 | |
| 524 | /* |
| 525 | * Next calculate the total available space and see if it is |
| 526 | * sufficient. We cannot overwrite previously buffered data |
| 527 | * past xindex because otherwise we would not be able to restart |
| 528 | * a broken link at the target's last point of commit. |
| 529 | */ |
| 530 | avail = jo->fifo.size - (jo->fifo.windex - jo->fifo.xindex); |
| 531 | KKASSERT(avail >= 0 && (avail & 15) == 0); |
| 532 | |
| 533 | if (avail < req) { |
| 534 | /* XXX MC_JOURNAL_STOP_IMM */ |
| 535 | jo->flags |= MC_JOURNAL_WWAIT; |
| 536 | ++jo->fifostalls; |
| 537 | tsleep(&jo->fifo.windex, 0, "jwrite", 0); |
| 538 | continue; |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * Create a pad record for any dead space and create an incomplete |
| 543 | * record for the live space, then return a pointer to the |
| 544 | * contiguous buffer space that was requested. |
| 545 | * |
| 546 | * NOTE: The worker thread will not flush past an incomplete |
| 547 | * record, so the reserved space can be filled in at-will. The |
| 548 | * journaling code must also be aware the reserved sections occuring |
| 549 | * after this one will also not be written out even if completed |
| 550 | * until this one is completed. |
| 551 | * |
| 552 | * The transaction id must accomodate real and potential pad creation. |
| 553 | */ |
| 554 | rawp = (void *)(jo->fifo.membase + (jo->fifo.windex & jo->fifo.mask)); |
| 555 | if (req != bytes) { |
| 556 | journal_build_pad(rawp, availtoend, jo->transid); |
| 557 | ++jo->transid; |
| 558 | rawp = (void *)jo->fifo.membase; |
| 559 | } |
| 560 | rawp->begmagic = JREC_INCOMPLETEMAGIC; /* updated by abort/commit */ |
| 561 | rawp->recsize = bytes; /* (unaligned size) */ |
| 562 | rawp->streamid = streamid | JREC_STREAMCTL_BEGIN; |
| 563 | rawp->transid = jo->transid; |
| 564 | jo->transid += 2; |
| 565 | |
| 566 | /* |
| 567 | * Issue a memory barrier to guarentee that the record data has been |
| 568 | * properly initialized before we advance the write index and return |
| 569 | * a pointer to the reserved record. Otherwise the worker thread |
| 570 | * could accidently run past us. |
| 571 | * |
| 572 | * Note that stream records are always 16-byte aligned. |
| 573 | */ |
| 574 | cpu_sfence(); |
| 575 | jo->fifo.windex += (req + 15) & ~15; |
| 576 | *rawpp = rawp; |
| 577 | return(rawp + 1); |
| 578 | } |
| 579 | /* not reached */ |
| 580 | *rawpp = NULL; |
| 581 | return(NULL); |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * Attempt to extend the stream record by <bytes> worth of payload space. |
| 586 | * |
| 587 | * If it is possible to extend the existing stream record no truncation |
| 588 | * occurs and the record is extended as specified. A pointer to the |
| 589 | * truncation offset within the payload space is returned. |
| 590 | * |
| 591 | * If it is not possible to do this the existing stream record is truncated |
| 592 | * and committed, and a new stream record of size <bytes> is created. A |
| 593 | * pointer to the base of the new stream record's payload space is returned. |
| 594 | * |
| 595 | * *rawpp is set to the new reservation in the case of a new record but |
| 596 | * the caller cannot depend on a comparison with the old rawp to determine if |
| 597 | * this case occurs because we could end up using the same memory FIFO |
| 598 | * offset for the new stream record. Use *newstreamrecp instead. |
| 599 | */ |
| 600 | static void * |
| 601 | journal_extend(struct journal *jo, struct journal_rawrecbeg **rawpp, |
| 602 | int truncbytes, int bytes, int *newstreamrecp) |
| 603 | { |
| 604 | struct journal_rawrecbeg *rawp; |
| 605 | int16_t streamid; |
| 606 | int availtoend; |
| 607 | int avail; |
| 608 | int osize; |
| 609 | int nsize; |
| 610 | int wbase; |
| 611 | void *rptr; |
| 612 | |
| 613 | *newstreamrecp = 0; |
| 614 | rawp = *rawpp; |
| 615 | osize = (rawp->recsize + 15) & ~15; |
| 616 | nsize = (rawp->recsize + bytes + 15) & ~15; |
| 617 | wbase = (char *)rawp - jo->fifo.membase; |
| 618 | |
| 619 | /* |
| 620 | * If the aligned record size does not change we can trivially adjust |
| 621 | * the record size. |
| 622 | */ |
| 623 | if (nsize == osize) { |
| 624 | rawp->recsize += bytes; |
| 625 | return((char *)(rawp + 1) + truncbytes); |
| 626 | } |
| 627 | |
| 628 | /* |
| 629 | * If the fifo's write index hasn't been modified since we made the |
| 630 | * reservation and we do not hit any boundary conditions, we can |
| 631 | * trivially make the record smaller or larger. |
| 632 | */ |
| 633 | if ((jo->fifo.windex & jo->fifo.mask) == wbase + osize) { |
| 634 | availtoend = jo->fifo.size - wbase; |
| 635 | avail = jo->fifo.size - (jo->fifo.windex - jo->fifo.xindex) + osize; |
| 636 | KKASSERT((availtoend & 15) == 0); |
| 637 | KKASSERT((avail & 15) == 0); |
| 638 | if (nsize <= avail && nsize <= availtoend) { |
| 639 | jo->fifo.windex += nsize - osize; |
| 640 | rawp->recsize += bytes; |
| 641 | return((char *)(rawp + 1) + truncbytes); |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | /* |
| 646 | * It was not possible to extend the buffer. Commit the current |
| 647 | * buffer and create a new one. We manually clear the BEGIN mark that |
| 648 | * journal_reserve() creates (because this is a continuing record, not |
| 649 | * the start of a new stream). |
| 650 | */ |
| 651 | streamid = rawp->streamid & JREC_STREAMID_MASK; |
| 652 | journal_commit(jo, rawpp, truncbytes, 0); |
| 653 | rptr = journal_reserve(jo, rawpp, streamid, bytes); |
| 654 | rawp = *rawpp; |
| 655 | rawp->streamid &= ~JREC_STREAMCTL_BEGIN; |
| 656 | *newstreamrecp = 1; |
| 657 | return(rptr); |
| 658 | } |
| 659 | |
| 660 | /* |
| 661 | * Abort a journal record. If the transaction record represents a stream |
| 662 | * BEGIN and we can reverse the fifo's write index we can simply reverse |
| 663 | * index the entire record, as if it were never reserved in the first place. |
| 664 | * |
| 665 | * Otherwise we set the JREC_STREAMCTL_ABORTED bit and commit the record |
| 666 | * with the payload truncated to 0 bytes. |
| 667 | */ |
| 668 | static void |
| 669 | journal_abort(struct journal *jo, struct journal_rawrecbeg **rawpp) |
| 670 | { |
| 671 | struct journal_rawrecbeg *rawp; |
| 672 | int osize; |
| 673 | |
| 674 | rawp = *rawpp; |
| 675 | osize = (rawp->recsize + 15) & ~15; |
| 676 | |
| 677 | if ((rawp->streamid & JREC_STREAMCTL_BEGIN) && |
| 678 | (jo->fifo.windex & jo->fifo.mask) == |
| 679 | (char *)rawp - jo->fifo.membase + osize) |
| 680 | { |
| 681 | jo->fifo.windex -= osize; |
| 682 | *rawpp = NULL; |
| 683 | } else { |
| 684 | rawp->streamid |= JREC_STREAMCTL_ABORTED; |
| 685 | journal_commit(jo, rawpp, 0, 1); |
| 686 | } |
| 687 | } |
| 688 | |
| 689 | /* |
| 690 | * Commit a journal record and potentially truncate it to the specified |
| 691 | * number of payload bytes. If you do not want to truncate the record, |
| 692 | * simply pass -1 for the bytes parameter. Do not pass rawp->recsize, that |
| 693 | * field includes header and trailer and will not be correct. Note that |
| 694 | * passing 0 will truncate the entire data payload of the record. |
| 695 | * |
| 696 | * The logical stream is terminated by this function. |
| 697 | * |
| 698 | * If truncation occurs, and it is not possible to physically optimize the |
| 699 | * memory FIFO due to other threads having reserved space after ours, |
| 700 | * the remaining reserved space will be covered by a pad record. |
| 701 | */ |
| 702 | static void |
| 703 | journal_commit(struct journal *jo, struct journal_rawrecbeg **rawpp, |
| 704 | int bytes, int closeout) |
| 705 | { |
| 706 | struct journal_rawrecbeg *rawp; |
| 707 | struct journal_rawrecend *rendp; |
| 708 | int osize; |
| 709 | int nsize; |
| 710 | |
| 711 | rawp = *rawpp; |
| 712 | *rawpp = NULL; |
| 713 | |
| 714 | KKASSERT((char *)rawp >= jo->fifo.membase && |
| 715 | (char *)rawp + rawp->recsize <= jo->fifo.membase + jo->fifo.size); |
| 716 | KKASSERT(((intptr_t)rawp & 15) == 0); |
| 717 | |
| 718 | /* |
| 719 | * Truncate the record if necessary. If the FIFO write index as still |
| 720 | * at the end of our record we can optimally backindex it. Otherwise |
| 721 | * we have to insert a pad record to cover the dead space. |
| 722 | * |
| 723 | * We calculate osize which is the 16-byte-aligned original recsize. |
| 724 | * We calculate nsize which is the 16-byte-aligned new recsize. |
| 725 | * |
| 726 | * Due to alignment issues or in case the passed truncation bytes is |
| 727 | * the same as the original payload, nsize may be equal to osize even |
| 728 | * if the committed bytes is less then the originally reserved bytes. |
| 729 | */ |
| 730 | if (bytes >= 0) { |
| 731 | KKASSERT(bytes >= 0 && bytes <= rawp->recsize - sizeof(struct journal_rawrecbeg) - sizeof(struct journal_rawrecend)); |
| 732 | osize = (rawp->recsize + 15) & ~15; |
| 733 | rawp->recsize = bytes + sizeof(struct journal_rawrecbeg) + |
| 734 | sizeof(struct journal_rawrecend); |
| 735 | nsize = (rawp->recsize + 15) & ~15; |
| 736 | KKASSERT(nsize <= osize); |
| 737 | if (osize == nsize) { |
| 738 | /* do nothing */ |
| 739 | } else if ((jo->fifo.windex & jo->fifo.mask) == (char *)rawp - jo->fifo.membase + osize) { |
| 740 | /* we are able to backindex the fifo */ |
| 741 | jo->fifo.windex -= osize - nsize; |
| 742 | } else { |
| 743 | /* we cannot backindex the fifo, emplace a pad in the dead space */ |
| 744 | journal_build_pad((void *)((char *)rawp + nsize), osize - nsize, |
| 745 | rawp->transid + 1); |
| 746 | } |
| 747 | } |
| 748 | |
| 749 | /* |
| 750 | * Fill in the trailer. Note that unlike pad records, the trailer will |
| 751 | * never overlap the header. |
| 752 | */ |
| 753 | rendp = (void *)((char *)rawp + |
| 754 | ((rawp->recsize + 15) & ~15) - sizeof(*rendp)); |
| 755 | rendp->endmagic = JREC_ENDMAGIC; |
| 756 | rendp->recsize = rawp->recsize; |
| 757 | rendp->check = 0; /* XXX check word, disabled for now */ |
| 758 | |
| 759 | /* |
| 760 | * Fill in begmagic last. This will allow the worker thread to proceed. |
| 761 | * Use a memory barrier to guarentee write ordering. Mark the stream |
| 762 | * as terminated if closeout is set. This is the typical case. |
| 763 | */ |
| 764 | if (closeout) |
| 765 | rawp->streamid |= JREC_STREAMCTL_END; |
| 766 | cpu_sfence(); /* memory and compiler barrier */ |
| 767 | rawp->begmagic = JREC_BEGMAGIC; |
| 768 | |
| 769 | journal_commit_wakeup(jo); |
| 770 | } |
| 771 | |
| 772 | /************************************************************************ |
| 773 | * TRANSACTION SUPPORT ROUTINES * |
| 774 | ************************************************************************ |
| 775 | * |
| 776 | * JRECORD_*() - routines to create subrecord transactions and embed them |
| 777 | * in the logical streams managed by the journal_*() routines. |
| 778 | */ |
| 779 | |
| 780 | /* |
| 781 | * Initialize the passed jrecord structure and start a new stream transaction |
| 782 | * by reserving an initial build space in the journal's memory FIFO. |
| 783 | */ |
| 784 | void |
| 785 | jrecord_init(struct journal *jo, struct jrecord *jrec, int16_t streamid) |
| 786 | { |
| 787 | bzero(jrec, sizeof(*jrec)); |
| 788 | jrec->jo = jo; |
| 789 | jrec->streamid = streamid; |
| 790 | jrec->stream_residual = JREC_DEFAULTSIZE; |
| 791 | jrec->stream_reserved = jrec->stream_residual; |
| 792 | jrec->stream_ptr = |
| 793 | journal_reserve(jo, &jrec->rawp, streamid, jrec->stream_reserved); |
| 794 | } |
| 795 | |
| 796 | /* |
| 797 | * Push a recursive record type. All pushes should have matching pops. |
| 798 | * The old parent is returned and the newly pushed record becomes the |
| 799 | * new parent. Note that the old parent's pointer may already be invalid |
| 800 | * or may become invalid if jrecord_write() had to build a new stream |
| 801 | * record, so the caller should not mess with the returned pointer in |
| 802 | * any way other then to save it. |
| 803 | */ |
| 804 | struct journal_subrecord * |
| 805 | jrecord_push(struct jrecord *jrec, int16_t rectype) |
| 806 | { |
| 807 | struct journal_subrecord *save; |
| 808 | |
| 809 | save = jrec->parent; |
| 810 | jrec->parent = jrecord_write(jrec, rectype|JMASK_NESTED, 0); |
| 811 | jrec->last = NULL; |
| 812 | KKASSERT(jrec->parent != NULL); |
| 813 | ++jrec->pushcount; |
| 814 | ++jrec->pushptrgood; /* cleared on flush */ |
| 815 | return(save); |
| 816 | } |
| 817 | |
| 818 | /* |
| 819 | * Pop a previously pushed sub-transaction. We must set JMASK_LAST |
| 820 | * on the last record written within the subtransaction. If the last |
| 821 | * record written is not accessible or if the subtransaction is empty, |
| 822 | * we must write out a pad record with JMASK_LAST set before popping. |
| 823 | * |
| 824 | * When popping a subtransaction the parent record's recsize field |
| 825 | * will be properly set. If the parent pointer is no longer valid |
| 826 | * (which can occur if the data has already been flushed out to the |
| 827 | * stream), the protocol spec allows us to leave it 0. |
| 828 | * |
| 829 | * The saved parent pointer which we restore may or may not be valid, |
| 830 | * and if not valid may or may not be NULL, depending on the value |
| 831 | * of pushptrgood. |
| 832 | */ |
| 833 | void |
| 834 | jrecord_pop(struct jrecord *jrec, struct journal_subrecord *save) |
| 835 | { |
| 836 | struct journal_subrecord *last; |
| 837 | |
| 838 | KKASSERT(jrec->pushcount > 0); |
| 839 | KKASSERT(jrec->residual == 0); |
| 840 | |
| 841 | /* |
| 842 | * Set JMASK_LAST on the last record we wrote at the current |
| 843 | * level. If last is NULL we either no longer have access to the |
| 844 | * record or the subtransaction was empty and we must write out a pad |
| 845 | * record. |
| 846 | */ |
| 847 | if ((last = jrec->last) == NULL) { |
| 848 | jrecord_write(jrec, JLEAF_PAD|JMASK_LAST, 0); |
| 849 | last = jrec->last; /* reload after possible flush */ |
| 850 | } else { |
| 851 | last->rectype |= JMASK_LAST; |
| 852 | } |
| 853 | |
| 854 | /* |
| 855 | * pushptrgood tells us how many levels of parent record pointers |
| 856 | * are valid. The jrec only stores the current parent record pointer |
| 857 | * (and it is only valid if pushptrgood != 0). The higher level parent |
| 858 | * record pointers are saved by the routines calling jrecord_push() and |
| 859 | * jrecord_pop(). These pointers may become stale and we determine |
| 860 | * that fact by tracking the count of valid parent pointers with |
| 861 | * pushptrgood. Pointers become invalid when their related stream |
| 862 | * record gets pushed out. |
| 863 | * |
| 864 | * If no pointer is available (the data has already been pushed out), |
| 865 | * then no fixup of e.g. the length field is possible for non-leaf |
| 866 | * nodes. The protocol allows for this situation by placing a larger |
| 867 | * burden on the program scanning the stream on the other end. |
| 868 | * |
| 869 | * [parentA] |
| 870 | * [node X] |
| 871 | * [parentB] |
| 872 | * [node Y] |
| 873 | * [node Z] |
| 874 | * (pop B) see NOTE B |
| 875 | * (pop A) see NOTE A |
| 876 | * |
| 877 | * NOTE B: This pop sets LAST in node Z if the node is still accessible, |
| 878 | * else a PAD record is appended and LAST is set in that. |
| 879 | * |
| 880 | * This pop sets the record size in parentB if parentB is still |
| 881 | * accessible, else the record size is left 0 (the scanner must |
| 882 | * deal with that). |
| 883 | * |
| 884 | * This pop sets the new 'last' record to parentB, the pointer |
| 885 | * to which may or may not still be accessible. |
| 886 | * |
| 887 | * NOTE A: This pop sets LAST in parentB if the node is still accessible, |
| 888 | * else a PAD record is appended and LAST is set in that. |
| 889 | * |
| 890 | * This pop sets the record size in parentA if parentA is still |
| 891 | * accessible, else the record size is left 0 (the scanner must |
| 892 | * deal with that). |
| 893 | * |
| 894 | * This pop sets the new 'last' record to parentA, the pointer |
| 895 | * to which may or may not still be accessible. |
| 896 | * |
| 897 | * Also note that the last record in the stream transaction, which in |
| 898 | * the above example is parentA, does not currently have the LAST bit |
| 899 | * set. |
| 900 | * |
| 901 | * The current parent becomes the last record relative to the |
| 902 | * saved parent passed into us. It's validity is based on |
| 903 | * whether pushptrgood is non-zero prior to decrementing. The saved |
| 904 | * parent becomes the new parent, and its validity is based on whether |
| 905 | * pushptrgood is non-zero after decrementing. |
| 906 | * |
| 907 | * The old jrec->parent may be NULL if it is no longer accessible. |
| 908 | * If pushptrgood is non-zero, however, it is guarenteed to not |
| 909 | * be NULL (since no flush occured). |
| 910 | */ |
| 911 | jrec->last = jrec->parent; |
| 912 | --jrec->pushcount; |
| 913 | if (jrec->pushptrgood) { |
| 914 | KKASSERT(jrec->last != NULL && last != NULL); |
| 915 | if (--jrec->pushptrgood == 0) { |
| 916 | jrec->parent = NULL; /* 'save' contains garbage or NULL */ |
| 917 | } else { |
| 918 | KKASSERT(save != NULL); |
| 919 | jrec->parent = save; /* 'save' must not be NULL */ |
| 920 | } |
| 921 | |
| 922 | /* |
| 923 | * Set the record size in the old parent. 'last' still points to |
| 924 | * the original last record in the subtransaction being popped, |
| 925 | * jrec->last points to the old parent (which became the last |
| 926 | * record relative to the new parent being popped into). |
| 927 | */ |
| 928 | jrec->last->recsize = (char *)last + last->recsize - (char *)jrec->last; |
| 929 | } else { |
| 930 | jrec->parent = NULL; |
| 931 | KKASSERT(jrec->last == NULL); |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | /* |
| 936 | * Write out a leaf record, including associated data. |
| 937 | */ |
| 938 | void |
| 939 | jrecord_leaf(struct jrecord *jrec, int16_t rectype, void *ptr, int bytes) |
| 940 | { |
| 941 | jrecord_write(jrec, rectype, bytes); |
| 942 | jrecord_data(jrec, ptr, bytes); |
| 943 | } |
| 944 | |
| 945 | /* |
| 946 | * Write a leaf record out and return a pointer to its base. The leaf |
| 947 | * record may contain potentially megabytes of data which is supplied |
| 948 | * in jrecord_data() calls. The exact amount must be specified in this |
| 949 | * call. |
| 950 | * |
| 951 | * THE RETURNED SUBRECORD POINTER IS ONLY VALID IMMEDIATELY AFTER THE |
| 952 | * CALL AND MAY BECOME INVALID AT ANY TIME. ONLY THE PUSH/POP CODE SHOULD |
| 953 | * USE THE RETURN VALUE. |
| 954 | */ |
| 955 | struct journal_subrecord * |
| 956 | jrecord_write(struct jrecord *jrec, int16_t rectype, int bytes) |
| 957 | { |
| 958 | struct journal_subrecord *last; |
| 959 | int pusheditout; |
| 960 | |
| 961 | /* |
| 962 | * Try to catch some obvious errors. Nesting records must specify a |
| 963 | * size of 0, and there should be no left-overs from previous operations |
| 964 | * (such as incomplete data writeouts). |
| 965 | */ |
| 966 | KKASSERT(bytes == 0 || (rectype & JMASK_NESTED) == 0); |
| 967 | KKASSERT(jrec->residual == 0); |
| 968 | |
| 969 | /* |
| 970 | * Check to see if the current stream record has enough room for |
| 971 | * the new subrecord header. If it doesn't we extend the current |
| 972 | * stream record. |
| 973 | * |
| 974 | * This may have the side effect of pushing out the current stream record |
| 975 | * and creating a new one. We must adjust our stream tracking fields |
| 976 | * accordingly. |
| 977 | */ |
| 978 | if (jrec->stream_residual < sizeof(struct journal_subrecord)) { |
| 979 | jrec->stream_ptr = journal_extend(jrec->jo, &jrec->rawp, |
| 980 | jrec->stream_reserved - jrec->stream_residual, |
| 981 | JREC_DEFAULTSIZE, &pusheditout); |
| 982 | if (pusheditout) { |
| 983 | /* |
| 984 | * If a pushout occured, the pushed out stream record was |
| 985 | * truncated as specified and the new record is exactly the |
| 986 | * extension size specified. |
| 987 | */ |
| 988 | jrec->stream_reserved = JREC_DEFAULTSIZE; |
| 989 | jrec->stream_residual = JREC_DEFAULTSIZE; |
| 990 | jrec->parent = NULL; /* no longer accessible */ |
| 991 | jrec->pushptrgood = 0; /* restored parents in pops no good */ |
| 992 | } else { |
| 993 | /* |
| 994 | * If no pushout occured the stream record is NOT truncated and |
| 995 | * IS extended. |
| 996 | */ |
| 997 | jrec->stream_reserved += JREC_DEFAULTSIZE; |
| 998 | jrec->stream_residual += JREC_DEFAULTSIZE; |
| 999 | } |
| 1000 | } |
| 1001 | last = (void *)jrec->stream_ptr; |
| 1002 | last->rectype = rectype; |
| 1003 | last->reserved = 0; |
| 1004 | |
| 1005 | /* |
| 1006 | * We may not know the record size for recursive records and the |
| 1007 | * header may become unavailable due to limited FIFO space. Write |
| 1008 | * -1 to indicate this special case. |
| 1009 | */ |
| 1010 | if ((rectype & JMASK_NESTED) && bytes == 0) |
| 1011 | last->recsize = -1; |
| 1012 | else |
| 1013 | last->recsize = sizeof(struct journal_subrecord) + bytes; |
| 1014 | jrec->last = last; |
| 1015 | jrec->residual = bytes; /* remaining data to be posted */ |
| 1016 | jrec->residual_align = -bytes & 7; /* post-data alignment required */ |
| 1017 | jrec->stream_ptr += sizeof(*last); /* current write pointer */ |
| 1018 | jrec->stream_residual -= sizeof(*last); /* space remaining in stream */ |
| 1019 | return(last); |
| 1020 | } |
| 1021 | |
| 1022 | /* |
| 1023 | * Write out the data associated with a leaf record. Any number of calls |
| 1024 | * to this routine may be made as long as the byte count adds up to the |
| 1025 | * amount originally specified in jrecord_write(). |
| 1026 | * |
| 1027 | * The act of writing out the leaf data may result in numerous stream records |
| 1028 | * being pushed out. Callers should be aware that even the associated |
| 1029 | * subrecord header may become inaccessible due to stream record pushouts. |
| 1030 | */ |
| 1031 | void |
| 1032 | jrecord_data(struct jrecord *jrec, const void *buf, int bytes) |
| 1033 | { |
| 1034 | int pusheditout; |
| 1035 | int extsize; |
| 1036 | |
| 1037 | KKASSERT(bytes >= 0 && bytes <= jrec->residual); |
| 1038 | |
| 1039 | /* |
| 1040 | * Push out stream records as long as there is insufficient room to hold |
| 1041 | * the remaining data. |
| 1042 | */ |
| 1043 | while (jrec->stream_residual < bytes) { |
| 1044 | /* |
| 1045 | * Fill in any remaining space in the current stream record. |
| 1046 | */ |
| 1047 | bcopy(buf, jrec->stream_ptr, jrec->stream_residual); |
| 1048 | buf = (const char *)buf + jrec->stream_residual; |
| 1049 | bytes -= jrec->stream_residual; |
| 1050 | /*jrec->stream_ptr += jrec->stream_residual;*/ |
| 1051 | jrec->residual -= jrec->stream_residual; |
| 1052 | jrec->stream_residual = 0; |
| 1053 | |
| 1054 | /* |
| 1055 | * Try to extend the current stream record, but no more then 1/4 |
| 1056 | * the size of the FIFO. |
| 1057 | */ |
| 1058 | extsize = jrec->jo->fifo.size >> 2; |
| 1059 | if (extsize > bytes) |
| 1060 | extsize = (bytes + 15) & ~15; |
| 1061 | |
| 1062 | jrec->stream_ptr = journal_extend(jrec->jo, &jrec->rawp, |
| 1063 | jrec->stream_reserved - jrec->stream_residual, |
| 1064 | extsize, &pusheditout); |
| 1065 | if (pusheditout) { |
| 1066 | jrec->stream_reserved = extsize; |
| 1067 | jrec->stream_residual = extsize; |
| 1068 | jrec->parent = NULL; /* no longer accessible */ |
| 1069 | jrec->last = NULL; /* no longer accessible */ |
| 1070 | jrec->pushptrgood = 0; /* restored parents in pops no good */ |
| 1071 | } else { |
| 1072 | jrec->stream_reserved += extsize; |
| 1073 | jrec->stream_residual += extsize; |
| 1074 | } |
| 1075 | } |
| 1076 | |
| 1077 | /* |
| 1078 | * Push out any remaining bytes into the current stream record. |
| 1079 | */ |
| 1080 | if (bytes) { |
| 1081 | bcopy(buf, jrec->stream_ptr, bytes); |
| 1082 | jrec->stream_ptr += bytes; |
| 1083 | jrec->stream_residual -= bytes; |
| 1084 | jrec->residual -= bytes; |
| 1085 | } |
| 1086 | |
| 1087 | /* |
| 1088 | * Handle data alignment requirements for the subrecord. Because the |
| 1089 | * stream record's data space is more strictly aligned, it must already |
| 1090 | * have sufficient space to hold any subrecord alignment slop. |
| 1091 | */ |
| 1092 | if (jrec->residual == 0 && jrec->residual_align) { |
| 1093 | KKASSERT(jrec->residual_align <= jrec->stream_residual); |
| 1094 | bzero(jrec->stream_ptr, jrec->residual_align); |
| 1095 | jrec->stream_ptr += jrec->residual_align; |
| 1096 | jrec->stream_residual -= jrec->residual_align; |
| 1097 | jrec->residual_align = 0; |
| 1098 | } |
| 1099 | } |
| 1100 | |
| 1101 | /* |
| 1102 | * We are finished with the transaction. This closes the transaction created |
| 1103 | * by jrecord_init(). |
| 1104 | * |
| 1105 | * NOTE: If abortit is not set then we must be at the top level with no |
| 1106 | * residual subrecord data left to output. |
| 1107 | * |
| 1108 | * If abortit is set then we can be in any state, all pushes will be |
| 1109 | * popped and it is ok for there to be residual data. This works |
| 1110 | * because the virtual stream itself is truncated. Scanners must deal |
| 1111 | * with this situation. |
| 1112 | * |
| 1113 | * The stream record will be committed or aborted as specified and jrecord |
| 1114 | * resources will be cleaned up. |
| 1115 | */ |
| 1116 | void |
| 1117 | jrecord_done(struct jrecord *jrec, int abortit) |
| 1118 | { |
| 1119 | KKASSERT(jrec->rawp != NULL); |
| 1120 | |
| 1121 | if (abortit) { |
| 1122 | journal_abort(jrec->jo, &jrec->rawp); |
| 1123 | } else { |
| 1124 | KKASSERT(jrec->pushcount == 0 && jrec->residual == 0); |
| 1125 | journal_commit(jrec->jo, &jrec->rawp, |
| 1126 | jrec->stream_reserved - jrec->stream_residual, 1); |
| 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * jrec should not be used beyond this point without another init, |
| 1131 | * but clean up some fields to ensure that we panic if it is. |
| 1132 | * |
| 1133 | * Note that jrec->rawp is NULLd out by journal_abort/journal_commit. |
| 1134 | */ |
| 1135 | jrec->jo = NULL; |
| 1136 | jrec->stream_ptr = NULL; |
| 1137 | } |
| 1138 | |
| 1139 | /************************************************************************ |
| 1140 | * LOW LEVEL RECORD SUPPORT ROUTINES * |
| 1141 | ************************************************************************ |
| 1142 | * |
| 1143 | * These routine create low level recursive and leaf subrecords representing |
| 1144 | * common filesystem structures. |
| 1145 | */ |
| 1146 | |
| 1147 | /* |
| 1148 | * Write out a filename path relative to the base of the mount point. |
| 1149 | * rectype is typically JLEAF_PATH{1,2,3,4}. |
| 1150 | */ |
| 1151 | void |
| 1152 | jrecord_write_path(struct jrecord *jrec, int16_t rectype, struct namecache *ncp) |
| 1153 | { |
| 1154 | char buf[64]; /* local buffer if it fits, else malloced */ |
| 1155 | char *base; |
| 1156 | int pathlen; |
| 1157 | int index; |
| 1158 | struct namecache *scan; |
| 1159 | |
| 1160 | /* |
| 1161 | * Pass 1 - figure out the number of bytes required. Include terminating |
| 1162 | * \0 on last element and '/' separator on other elements. |
| 1163 | * |
| 1164 | * The namecache topology terminates at the root of the filesystem |
| 1165 | * (the normal lookup code would then continue by using the mount |
| 1166 | * structure to figure out what it was mounted on). |
| 1167 | */ |
| 1168 | again: |
| 1169 | pathlen = 0; |
| 1170 | for (scan = ncp; scan; scan = scan->nc_parent) { |
| 1171 | if (scan->nc_nlen > 0) |
| 1172 | pathlen += scan->nc_nlen + 1; |
| 1173 | } |
| 1174 | |
| 1175 | if (pathlen <= sizeof(buf)) |
| 1176 | base = buf; |
| 1177 | else |
| 1178 | base = kmalloc(pathlen, M_TEMP, M_INTWAIT); |
| 1179 | |
| 1180 | /* |
| 1181 | * Pass 2 - generate the path buffer |
| 1182 | */ |
| 1183 | index = pathlen; |
| 1184 | for (scan = ncp; scan; scan = scan->nc_parent) { |
| 1185 | if (scan->nc_nlen == 0) |
| 1186 | continue; |
| 1187 | if (scan->nc_nlen >= index) { |
| 1188 | if (base != buf) |
| 1189 | kfree(base, M_TEMP); |
| 1190 | goto again; |
| 1191 | } |
| 1192 | if (index == pathlen) |
| 1193 | base[--index] = 0; |
| 1194 | else |
| 1195 | base[--index] = '/'; |
| 1196 | index -= scan->nc_nlen; |
| 1197 | bcopy(scan->nc_name, base + index, scan->nc_nlen); |
| 1198 | } |
| 1199 | jrecord_leaf(jrec, rectype, base + index, pathlen - index); |
| 1200 | if (base != buf) |
| 1201 | kfree(base, M_TEMP); |
| 1202 | } |
| 1203 | |
| 1204 | /* |
| 1205 | * Write out a file attribute structure. While somewhat inefficient, using |
| 1206 | * a recursive data structure is the most portable and extensible way. |
| 1207 | */ |
| 1208 | void |
| 1209 | jrecord_write_vattr(struct jrecord *jrec, struct vattr *vat) |
| 1210 | { |
| 1211 | void *save; |
| 1212 | |
| 1213 | save = jrecord_push(jrec, JTYPE_VATTR); |
| 1214 | if (vat->va_type != VNON) |
| 1215 | jrecord_leaf(jrec, JLEAF_VTYPE, &vat->va_type, sizeof(vat->va_type)); |
| 1216 | if (vat->va_mode != (mode_t)VNOVAL) |
| 1217 | jrecord_leaf(jrec, JLEAF_MODES, &vat->va_mode, sizeof(vat->va_mode)); |
| 1218 | if (vat->va_nlink != VNOVAL) |
| 1219 | jrecord_leaf(jrec, JLEAF_NLINK, &vat->va_nlink, sizeof(vat->va_nlink)); |
| 1220 | if (vat->va_uid != VNOVAL) |
| 1221 | jrecord_leaf(jrec, JLEAF_UID, &vat->va_uid, sizeof(vat->va_uid)); |
| 1222 | if (vat->va_gid != VNOVAL) |
| 1223 | jrecord_leaf(jrec, JLEAF_GID, &vat->va_gid, sizeof(vat->va_gid)); |
| 1224 | if (vat->va_fsid != VNOVAL) |
| 1225 | jrecord_leaf(jrec, JLEAF_FSID, &vat->va_fsid, sizeof(vat->va_fsid)); |
| 1226 | if (vat->va_fileid != VNOVAL) |
| 1227 | jrecord_leaf(jrec, JLEAF_INUM, &vat->va_fileid, sizeof(vat->va_fileid)); |
| 1228 | if (vat->va_size != VNOVAL) |
| 1229 | jrecord_leaf(jrec, JLEAF_SIZE, &vat->va_size, sizeof(vat->va_size)); |
| 1230 | if (vat->va_atime.tv_sec != VNOVAL) |
| 1231 | jrecord_leaf(jrec, JLEAF_ATIME, &vat->va_atime, sizeof(vat->va_atime)); |
| 1232 | if (vat->va_mtime.tv_sec != VNOVAL) |
| 1233 | jrecord_leaf(jrec, JLEAF_MTIME, &vat->va_mtime, sizeof(vat->va_mtime)); |
| 1234 | if (vat->va_ctime.tv_sec != VNOVAL) |
| 1235 | jrecord_leaf(jrec, JLEAF_CTIME, &vat->va_ctime, sizeof(vat->va_ctime)); |
| 1236 | if (vat->va_gen != VNOVAL) |
| 1237 | jrecord_leaf(jrec, JLEAF_GEN, &vat->va_gen, sizeof(vat->va_gen)); |
| 1238 | if (vat->va_flags != VNOVAL) |
| 1239 | jrecord_leaf(jrec, JLEAF_FLAGS, &vat->va_flags, sizeof(vat->va_flags)); |
| 1240 | if (vat->va_rmajor != VNOVAL) { |
| 1241 | udev_t rdev = makeudev(vat->va_rmajor, vat->va_rminor); |
| 1242 | jrecord_leaf(jrec, JLEAF_UDEV, &rdev, sizeof(rdev)); |
| 1243 | jrecord_leaf(jrec, JLEAF_UMAJOR, &vat->va_rmajor, sizeof(vat->va_rmajor)); |
| 1244 | jrecord_leaf(jrec, JLEAF_UMINOR, &vat->va_rminor, sizeof(vat->va_rminor)); |
| 1245 | } |
| 1246 | #if 0 |
| 1247 | if (vat->va_filerev != VNOVAL) |
| 1248 | jrecord_leaf(jrec, JLEAF_FILEREV, &vat->va_filerev, sizeof(vat->va_filerev)); |
| 1249 | #endif |
| 1250 | jrecord_pop(jrec, save); |
| 1251 | } |
| 1252 | |
| 1253 | /* |
| 1254 | * Write out the creds used to issue a file operation. If a process is |
| 1255 | * available write out additional tracking information related to the |
| 1256 | * process. |
| 1257 | * |
| 1258 | * XXX additional tracking info |
| 1259 | * XXX tty line info |
| 1260 | */ |
| 1261 | void |
| 1262 | jrecord_write_cred(struct jrecord *jrec, struct thread *td, struct ucred *cred) |
| 1263 | { |
| 1264 | void *save; |
| 1265 | struct proc *p; |
| 1266 | |
| 1267 | save = jrecord_push(jrec, JTYPE_CRED); |
| 1268 | jrecord_leaf(jrec, JLEAF_UID, &cred->cr_uid, sizeof(cred->cr_uid)); |
| 1269 | jrecord_leaf(jrec, JLEAF_GID, &cred->cr_gid, sizeof(cred->cr_gid)); |
| 1270 | if (td && (p = td->td_proc) != NULL) { |
| 1271 | jrecord_leaf(jrec, JLEAF_PID, &p->p_pid, sizeof(p->p_pid)); |
| 1272 | jrecord_leaf(jrec, JLEAF_COMM, p->p_comm, sizeof(p->p_comm)); |
| 1273 | } |
| 1274 | jrecord_pop(jrec, save); |
| 1275 | } |
| 1276 | |
| 1277 | /* |
| 1278 | * Write out information required to identify a vnode |
| 1279 | * |
| 1280 | * XXX this needs work. We should write out the inode number as well, |
| 1281 | * and in fact avoid writing out the file path for seqential writes |
| 1282 | * occuring within e.g. a certain period of time. |
| 1283 | */ |
| 1284 | void |
| 1285 | jrecord_write_vnode_ref(struct jrecord *jrec, struct vnode *vp) |
| 1286 | { |
| 1287 | struct nchandle nch; |
| 1288 | |
| 1289 | nch.mount = vp->v_mount; |
| 1290 | spin_lock_wr(&vp->v_spinlock); |
| 1291 | TAILQ_FOREACH(nch.ncp, &vp->v_namecache, nc_vnode) { |
| 1292 | if ((nch.ncp->nc_flag & (NCF_UNRESOLVED|NCF_DESTROYED)) == 0) |
| 1293 | break; |
| 1294 | } |
| 1295 | if (nch.ncp) { |
| 1296 | cache_hold(&nch); |
| 1297 | spin_unlock_wr(&vp->v_spinlock); |
| 1298 | jrecord_write_path(jrec, JLEAF_PATH_REF, nch.ncp); |
| 1299 | cache_drop(&nch); |
| 1300 | } else { |
| 1301 | spin_unlock_wr(&vp->v_spinlock); |
| 1302 | } |
| 1303 | } |
| 1304 | |
| 1305 | void |
| 1306 | jrecord_write_vnode_link(struct jrecord *jrec, struct vnode *vp, |
| 1307 | struct namecache *notncp) |
| 1308 | { |
| 1309 | struct nchandle nch; |
| 1310 | |
| 1311 | nch.mount = vp->v_mount; |
| 1312 | spin_lock_wr(&vp->v_spinlock); |
| 1313 | TAILQ_FOREACH(nch.ncp, &vp->v_namecache, nc_vnode) { |
| 1314 | if (nch.ncp == notncp) |
| 1315 | continue; |
| 1316 | if ((nch.ncp->nc_flag & (NCF_UNRESOLVED|NCF_DESTROYED)) == 0) |
| 1317 | break; |
| 1318 | } |
| 1319 | if (nch.ncp) { |
| 1320 | cache_hold(&nch); |
| 1321 | spin_unlock_wr(&vp->v_spinlock); |
| 1322 | jrecord_write_path(jrec, JLEAF_PATH_REF, nch.ncp); |
| 1323 | cache_drop(&nch); |
| 1324 | } else { |
| 1325 | spin_unlock_wr(&vp->v_spinlock); |
| 1326 | } |
| 1327 | } |
| 1328 | |
| 1329 | /* |
| 1330 | * Write out the data represented by a pagelist |
| 1331 | */ |
| 1332 | void |
| 1333 | jrecord_write_pagelist(struct jrecord *jrec, int16_t rectype, |
| 1334 | struct vm_page **pglist, int *rtvals, int pgcount, |
| 1335 | off_t offset) |
| 1336 | { |
| 1337 | struct msf_buf *msf; |
| 1338 | int error; |
| 1339 | int b; |
| 1340 | int i; |
| 1341 | |
| 1342 | i = 0; |
| 1343 | while (i < pgcount) { |
| 1344 | /* |
| 1345 | * Find the next valid section. Skip any invalid elements |
| 1346 | */ |
| 1347 | if (rtvals[i] != VM_PAGER_OK) { |
| 1348 | ++i; |
| 1349 | offset += PAGE_SIZE; |
| 1350 | continue; |
| 1351 | } |
| 1352 | |
| 1353 | /* |
| 1354 | * Figure out how big the valid section is, capping I/O at what the |
| 1355 | * MSFBUF can represent. |
| 1356 | */ |
| 1357 | b = i; |
| 1358 | while (i < pgcount && i - b != XIO_INTERNAL_PAGES && |
| 1359 | rtvals[i] == VM_PAGER_OK |
| 1360 | ) { |
| 1361 | ++i; |
| 1362 | } |
| 1363 | |
| 1364 | /* |
| 1365 | * And write it out. |
| 1366 | */ |
| 1367 | if (i - b) { |
| 1368 | error = msf_map_pagelist(&msf, pglist + b, i - b, 0); |
| 1369 | if (error == 0) { |
| 1370 | kprintf("RECORD PUTPAGES %d\n", msf_buf_bytes(msf)); |
| 1371 | jrecord_leaf(jrec, JLEAF_SEEKPOS, &offset, sizeof(offset)); |
| 1372 | jrecord_leaf(jrec, rectype, |
| 1373 | msf_buf_kva(msf), msf_buf_bytes(msf)); |
| 1374 | msf_buf_free(msf); |
| 1375 | } else { |
| 1376 | kprintf("jrecord_write_pagelist: mapping failure\n"); |
| 1377 | } |
| 1378 | offset += (off_t)(i - b) << PAGE_SHIFT; |
| 1379 | } |
| 1380 | } |
| 1381 | } |
| 1382 | |
| 1383 | /* |
| 1384 | * Write out the data represented by a UIO. |
| 1385 | */ |
| 1386 | struct jwuio_info { |
| 1387 | struct jrecord *jrec; |
| 1388 | int16_t rectype; |
| 1389 | }; |
| 1390 | |
| 1391 | static int jrecord_write_uio_callback(void *info, char *buf, int bytes); |
| 1392 | |
| 1393 | void |
| 1394 | jrecord_write_uio(struct jrecord *jrec, int16_t rectype, struct uio *uio) |
| 1395 | { |
| 1396 | struct jwuio_info info = { jrec, rectype }; |
| 1397 | int error; |
| 1398 | |
| 1399 | if (uio->uio_segflg != UIO_NOCOPY) { |
| 1400 | jrecord_leaf(jrec, JLEAF_SEEKPOS, &uio->uio_offset, |
| 1401 | sizeof(uio->uio_offset)); |
| 1402 | error = msf_uio_iterate(uio, jrecord_write_uio_callback, &info); |
| 1403 | if (error) |
| 1404 | kprintf("XXX warning uio iterate failed %d\n", error); |
| 1405 | } |
| 1406 | } |
| 1407 | |
| 1408 | static int |
| 1409 | jrecord_write_uio_callback(void *info_arg, char *buf, int bytes) |
| 1410 | { |
| 1411 | struct jwuio_info *info = info_arg; |
| 1412 | |
| 1413 | jrecord_leaf(info->jrec, info->rectype, buf, bytes); |
| 1414 | return(0); |
| 1415 | } |
| 1416 | |
| 1417 | void |
| 1418 | jrecord_file_data(struct jrecord *jrec, struct vnode *vp, |
| 1419 | off_t off, off_t bytes) |
| 1420 | { |
| 1421 | const int bufsize = 8192; |
| 1422 | char *buf; |
| 1423 | int error; |
| 1424 | int n; |
| 1425 | |
| 1426 | buf = kmalloc(bufsize, M_JOURNAL, M_WAITOK); |
| 1427 | jrecord_leaf(jrec, JLEAF_SEEKPOS, &off, sizeof(off)); |
| 1428 | while (bytes) { |
| 1429 | n = (bytes > bufsize) ? bufsize : (int)bytes; |
| 1430 | error = vn_rdwr(UIO_READ, vp, buf, n, off, UIO_SYSSPACE, IO_NODELOCKED, |
| 1431 | proc0.p_ucred, NULL); |
| 1432 | if (error) { |
| 1433 | jrecord_leaf(jrec, JLEAF_ERROR, &error, sizeof(error)); |
| 1434 | break; |
| 1435 | } |
| 1436 | jrecord_leaf(jrec, JLEAF_FILEDATA, buf, n); |
| 1437 | bytes -= n; |
| 1438 | off += n; |
| 1439 | } |
| 1440 | kfree(buf, M_JOURNAL); |
| 1441 | } |
| 1442 | |