1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 25 * Copyright (c) 2015 by Chunwei Chen. All rights reserved. 26 * Copyright 2017 Nexenta Systems, Inc. 27 */ 28 29/* Portions Copyright 2007 Jeremy Teo */ 30/* Portions Copyright 2010 Robert Milkowski */ 31 32#include <sys/types.h> 33#include <sys/param.h> 34#include <sys/time.h> 35#include <sys/sysmacros.h> 36#include <sys/vfs.h> 37#include <sys/uio_impl.h> 38#include <sys/file.h> 39#include <sys/stat.h> 40#include <sys/kmem.h> 41#include <sys/cmn_err.h> 42#include <sys/errno.h> 43#include <sys/zfs_dir.h> 44#include <sys/zfs_acl.h> 45#include <sys/zfs_ioctl.h> 46#include <sys/fs/zfs.h> 47#include <sys/dmu.h> 48#include <sys/dmu_objset.h> 49#include <sys/spa.h> 50#include <sys/txg.h> 51#include <sys/dbuf.h> 52#include <sys/policy.h> 53#include <sys/zfs_vnops.h> 54#include <sys/zfs_quota.h> 55#include <sys/zfs_vfsops.h> 56#include <sys/zfs_znode.h> 57 58 59static ulong_t zfs_fsync_sync_cnt = 4; 60 61int 62zfs_fsync(znode_t *zp, int syncflag, cred_t *cr) 63{ 64 zfsvfs_t *zfsvfs = ZTOZSB(zp); 65 66 (void) tsd_set(zfs_fsyncer_key, (void *)zfs_fsync_sync_cnt); 67 68 if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) { 69 ZFS_ENTER(zfsvfs); 70 ZFS_VERIFY_ZP(zp); 71 zil_commit(zfsvfs->z_log, zp->z_id); 72 ZFS_EXIT(zfsvfs); 73 } 74 tsd_set(zfs_fsyncer_key, NULL); 75 76 return (0); 77} 78 79 80#if defined(SEEK_HOLE) && defined(SEEK_DATA) 81/* 82 * Lseek support for finding holes (cmd == SEEK_HOLE) and 83 * data (cmd == SEEK_DATA). "off" is an in/out parameter. 84 */ 85static int 86zfs_holey_common(znode_t *zp, ulong_t cmd, loff_t *off) 87{ 88 uint64_t noff = (uint64_t)*off; /* new offset */ 89 uint64_t file_sz; 90 int error; 91 boolean_t hole; 92 93 file_sz = zp->z_size; 94 if (noff >= file_sz) { 95 return (SET_ERROR(ENXIO)); 96 } 97 98 if (cmd == F_SEEK_HOLE) 99 hole = B_TRUE; 100 else 101 hole = B_FALSE; 102 103 error = dmu_offset_next(ZTOZSB(zp)->z_os, zp->z_id, hole, &noff); 104 105 if (error == ESRCH) 106 return (SET_ERROR(ENXIO)); 107 108 /* file was dirty, so fall back to using generic logic */ 109 if (error == EBUSY) { 110 if (hole) 111 *off = file_sz; 112 113 return (0); 114 } 115 116 /* 117 * We could find a hole that begins after the logical end-of-file, 118 * because dmu_offset_next() only works on whole blocks. If the 119 * EOF falls mid-block, then indicate that the "virtual hole" 120 * at the end of the file begins at the logical EOF, rather than 121 * at the end of the last block. 122 */ 123 if (noff > file_sz) { 124 ASSERT(hole); 125 noff = file_sz; 126 } 127 128 if (noff < *off) 129 return (error); 130 *off = noff; 131 return (error); 132} 133 134int 135zfs_holey(znode_t *zp, ulong_t cmd, loff_t *off) 136{ 137 zfsvfs_t *zfsvfs = ZTOZSB(zp); 138 int error; 139 140 ZFS_ENTER(zfsvfs); 141 ZFS_VERIFY_ZP(zp); 142 143 error = zfs_holey_common(zp, cmd, off); 144 145 ZFS_EXIT(zfsvfs); 146 return (error); 147} 148#endif /* SEEK_HOLE && SEEK_DATA */ 149 150/*ARGSUSED*/ 151int 152zfs_access(znode_t *zp, int mode, int flag, cred_t *cr) 153{ 154 zfsvfs_t *zfsvfs = ZTOZSB(zp); 155 int error; 156 157 ZFS_ENTER(zfsvfs); 158 ZFS_VERIFY_ZP(zp); 159 160 if (flag & V_ACE_MASK) 161 error = zfs_zaccess(zp, mode, flag, B_FALSE, cr); 162 else 163 error = zfs_zaccess_rwx(zp, mode, flag, cr); 164 165 ZFS_EXIT(zfsvfs); 166 return (error); 167} 168 169static unsigned long zfs_vnops_read_chunk_size = 1024 * 1024; /* Tunable */ 170 171/* 172 * Read bytes from specified file into supplied buffer. 173 * 174 * IN: zp - inode of file to be read from. 175 * uio - structure supplying read location, range info, 176 * and return buffer. 177 * ioflag - O_SYNC flags; used to provide FRSYNC semantics. 178 * O_DIRECT flag; used to bypass page cache. 179 * cr - credentials of caller. 180 * 181 * OUT: uio - updated offset and range, buffer filled. 182 * 183 * RETURN: 0 on success, error code on failure. 184 * 185 * Side Effects: 186 * inode - atime updated if byte count > 0 187 */ 188/* ARGSUSED */ 189int 190zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr) 191{ 192 int error = 0; 193 boolean_t frsync = B_FALSE; 194 195 zfsvfs_t *zfsvfs = ZTOZSB(zp); 196 ZFS_ENTER(zfsvfs); 197 ZFS_VERIFY_ZP(zp); 198 199 if (zp->z_pflags & ZFS_AV_QUARANTINED) { 200 ZFS_EXIT(zfsvfs); 201 return (SET_ERROR(EACCES)); 202 } 203 204 /* We don't copy out anything useful for directories. */ 205 if (Z_ISDIR(ZTOTYPE(zp))) { 206 ZFS_EXIT(zfsvfs); 207 return (SET_ERROR(EISDIR)); 208 } 209 210 /* 211 * Validate file offset 212 */ 213 if (zfs_uio_offset(uio) < (offset_t)0) { 214 ZFS_EXIT(zfsvfs); 215 return (SET_ERROR(EINVAL)); 216 } 217 218 /* 219 * Fasttrack empty reads 220 */ 221 if (zfs_uio_resid(uio) == 0) { 222 ZFS_EXIT(zfsvfs); 223 return (0); 224 } 225 226#ifdef FRSYNC 227 /* 228 * If we're in FRSYNC mode, sync out this znode before reading it. 229 * Only do this for non-snapshots. 230 * 231 * Some platforms do not support FRSYNC and instead map it 232 * to O_SYNC, which results in unnecessary calls to zil_commit. We 233 * only honor FRSYNC requests on platforms which support it. 234 */ 235 frsync = !!(ioflag & FRSYNC); 236#endif 237 if (zfsvfs->z_log && 238 (frsync || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)) 239 zil_commit(zfsvfs->z_log, zp->z_id); 240 241 /* 242 * Lock the range against changes. 243 */ 244 zfs_locked_range_t *lr = zfs_rangelock_enter(&zp->z_rangelock, 245 zfs_uio_offset(uio), zfs_uio_resid(uio), RL_READER); 246 247 /* 248 * If we are reading past end-of-file we can skip 249 * to the end; but we might still need to set atime. 250 */ 251 if (zfs_uio_offset(uio) >= zp->z_size) { 252 error = 0; 253 goto out; 254 } 255 256 ASSERT(zfs_uio_offset(uio) < zp->z_size); 257 ssize_t n = MIN(zfs_uio_resid(uio), zp->z_size - zfs_uio_offset(uio)); 258 ssize_t start_resid = n; 259 260 while (n > 0) { 261 ssize_t nbytes = MIN(n, zfs_vnops_read_chunk_size - 262 P2PHASE(zfs_uio_offset(uio), zfs_vnops_read_chunk_size)); 263#ifdef UIO_NOCOPY 264 if (zfs_uio_segflg(uio) == UIO_NOCOPY) 265 error = mappedread_sf(zp, nbytes, uio); 266 else 267#endif 268 if (zn_has_cached_data(zp) && !(ioflag & O_DIRECT)) { 269 error = mappedread(zp, nbytes, uio); 270 } else { 271 error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl), 272 uio, nbytes); 273 } 274 275 if (error) { 276 /* convert checksum errors into IO errors */ 277 if (error == ECKSUM) 278 error = SET_ERROR(EIO); 279 break; 280 } 281 282 n -= nbytes; 283 } 284 285 int64_t nread = start_resid - n; 286 dataset_kstats_update_read_kstats(&zfsvfs->z_kstat, nread); 287 task_io_account_read(nread); 288out: 289 zfs_rangelock_exit(lr); 290 291 ZFS_ACCESSTIME_STAMP(zfsvfs, zp); 292 ZFS_EXIT(zfsvfs); 293 return (error); 294} 295 296/* 297 * Write the bytes to a file. 298 * 299 * IN: zp - znode of file to be written to. 300 * uio - structure supplying write location, range info, 301 * and data buffer. 302 * ioflag - O_APPEND flag set if in append mode. 303 * O_DIRECT flag; used to bypass page cache. 304 * cr - credentials of caller. 305 * 306 * OUT: uio - updated offset and range. 307 * 308 * RETURN: 0 if success 309 * error code if failure 310 * 311 * Timestamps: 312 * ip - ctime|mtime updated if byte count > 0 313 */ 314 315/* ARGSUSED */ 316int 317zfs_write(znode_t *zp, zfs_uio_t *uio, int ioflag, cred_t *cr) 318{ 319 int error = 0; 320 ssize_t start_resid = zfs_uio_resid(uio); 321 322 /* 323 * Fasttrack empty write 324 */ 325 ssize_t n = start_resid; 326 if (n == 0) 327 return (0); 328 329 zfsvfs_t *zfsvfs = ZTOZSB(zp); 330 ZFS_ENTER(zfsvfs); 331 ZFS_VERIFY_ZP(zp); 332 333 sa_bulk_attr_t bulk[4]; 334 int count = 0; 335 uint64_t mtime[2], ctime[2]; 336 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16); 337 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16); 338 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL, 339 &zp->z_size, 8); 340 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL, 341 &zp->z_pflags, 8); 342 343 /* 344 * Callers might not be able to detect properly that we are read-only, 345 * so check it explicitly here. 346 */ 347 if (zfs_is_readonly(zfsvfs)) { 348 ZFS_EXIT(zfsvfs); 349 return (SET_ERROR(EROFS)); 350 } 351 352 /* 353 * If immutable or not appending then return EPERM. 354 * Intentionally allow ZFS_READONLY through here. 355 * See zfs_zaccess_common() 356 */ 357 if ((zp->z_pflags & ZFS_IMMUTABLE) || 358 ((zp->z_pflags & ZFS_APPENDONLY) && !(ioflag & O_APPEND) && 359 (zfs_uio_offset(uio) < zp->z_size))) { 360 ZFS_EXIT(zfsvfs); 361 return (SET_ERROR(EPERM)); 362 } 363 364 /* 365 * Validate file offset 366 */ 367 offset_t woff = ioflag & O_APPEND ? zp->z_size : zfs_uio_offset(uio); 368 if (woff < 0) { 369 ZFS_EXIT(zfsvfs); 370 return (SET_ERROR(EINVAL)); 371 } 372 373 const uint64_t max_blksz = zfsvfs->z_max_blksz; 374 375 /* 376 * Pre-fault the pages to ensure slow (eg NFS) pages 377 * don't hold up txg. 378 * Skip this if uio contains loaned arc_buf. 379 */ 380 if (zfs_uio_prefaultpages(MIN(n, max_blksz), uio)) { 381 ZFS_EXIT(zfsvfs); 382 return (SET_ERROR(EFAULT)); 383 } 384 385 /* 386 * If in append mode, set the io offset pointer to eof. 387 */ 388 zfs_locked_range_t *lr; 389 if (ioflag & O_APPEND) { 390 /* 391 * Obtain an appending range lock to guarantee file append 392 * semantics. We reset the write offset once we have the lock. 393 */ 394 lr = zfs_rangelock_enter(&zp->z_rangelock, 0, n, RL_APPEND); 395 woff = lr->lr_offset; 396 if (lr->lr_length == UINT64_MAX) { 397 /* 398 * We overlocked the file because this write will cause 399 * the file block size to increase. 400 * Note that zp_size cannot change with this lock held. 401 */ 402 woff = zp->z_size; 403 } 404 zfs_uio_setoffset(uio, woff); 405 } else { 406 /* 407 * Note that if the file block size will change as a result of 408 * this write, then this range lock will lock the entire file 409 * so that we can re-write the block safely. 410 */ 411 lr = zfs_rangelock_enter(&zp->z_rangelock, woff, n, RL_WRITER); 412 } 413 414 if (zn_rlimit_fsize(zp, uio)) { 415 zfs_rangelock_exit(lr); 416 ZFS_EXIT(zfsvfs); 417 return (SET_ERROR(EFBIG)); 418 } 419 420 const rlim64_t limit = MAXOFFSET_T; 421 422 if (woff >= limit) { 423 zfs_rangelock_exit(lr); 424 ZFS_EXIT(zfsvfs); 425 return (SET_ERROR(EFBIG)); 426 } 427 428 if (n > limit - woff) 429 n = limit - woff; 430 431 uint64_t end_size = MAX(zp->z_size, woff + n); 432 zilog_t *zilog = zfsvfs->z_log; 433 434 const uint64_t uid = KUID_TO_SUID(ZTOUID(zp)); 435 const uint64_t gid = KGID_TO_SGID(ZTOGID(zp)); 436 const uint64_t projid = zp->z_projid; 437 438 /* 439 * Write the file in reasonable size chunks. Each chunk is written 440 * in a separate transaction; this keeps the intent log records small 441 * and allows us to do more fine-grained space accounting. 442 */ 443 while (n > 0) { 444 woff = zfs_uio_offset(uio); 445 446 if (zfs_id_overblockquota(zfsvfs, DMU_USERUSED_OBJECT, uid) || 447 zfs_id_overblockquota(zfsvfs, DMU_GROUPUSED_OBJECT, gid) || 448 (projid != ZFS_DEFAULT_PROJID && 449 zfs_id_overblockquota(zfsvfs, DMU_PROJECTUSED_OBJECT, 450 projid))) { 451 error = SET_ERROR(EDQUOT); 452 break; 453 } 454 455 arc_buf_t *abuf = NULL; 456 if (n >= max_blksz && woff >= zp->z_size && 457 P2PHASE(woff, max_blksz) == 0 && 458 zp->z_blksz == max_blksz) { 459 /* 460 * This write covers a full block. "Borrow" a buffer 461 * from the dmu so that we can fill it before we enter 462 * a transaction. This avoids the possibility of 463 * holding up the transaction if the data copy hangs 464 * up on a pagefault (e.g., from an NFS server mapping). 465 */ 466 size_t cbytes; 467 468 abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl), 469 max_blksz); 470 ASSERT(abuf != NULL); 471 ASSERT(arc_buf_size(abuf) == max_blksz); 472 if ((error = zfs_uiocopy(abuf->b_data, max_blksz, 473 UIO_WRITE, uio, &cbytes))) { 474 dmu_return_arcbuf(abuf); 475 break; 476 } 477 ASSERT3S(cbytes, ==, max_blksz); 478 } 479 480 /* 481 * Start a transaction. 482 */ 483 dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os); 484 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE); 485 dmu_buf_impl_t *db = (dmu_buf_impl_t *)sa_get_db(zp->z_sa_hdl); 486 DB_DNODE_ENTER(db); 487 dmu_tx_hold_write_by_dnode(tx, DB_DNODE(db), woff, 488 MIN(n, max_blksz)); 489 DB_DNODE_EXIT(db); 490 zfs_sa_upgrade_txholds(tx, zp); 491 error = dmu_tx_assign(tx, TXG_WAIT); 492 if (error) { 493 dmu_tx_abort(tx); 494 if (abuf != NULL) 495 dmu_return_arcbuf(abuf); 496 break; 497 } 498 499 /* 500 * If rangelock_enter() over-locked we grow the blocksize 501 * and then reduce the lock range. This will only happen 502 * on the first iteration since rangelock_reduce() will 503 * shrink down lr_length to the appropriate size. 504 */ 505 if (lr->lr_length == UINT64_MAX) { 506 uint64_t new_blksz; 507 508 if (zp->z_blksz > max_blksz) { 509 /* 510 * File's blocksize is already larger than the 511 * "recordsize" property. Only let it grow to 512 * the next power of 2. 513 */ 514 ASSERT(!ISP2(zp->z_blksz)); 515 new_blksz = MIN(end_size, 516 1 << highbit64(zp->z_blksz)); 517 } else { 518 new_blksz = MIN(end_size, max_blksz); 519 } 520 zfs_grow_blocksize(zp, new_blksz, tx); 521 zfs_rangelock_reduce(lr, woff, n); 522 } 523 524 /* 525 * XXX - should we really limit each write to z_max_blksz? 526 * Perhaps we should use SPA_MAXBLOCKSIZE chunks? 527 */ 528 const ssize_t nbytes = 529 MIN(n, max_blksz - P2PHASE(woff, max_blksz)); 530 531 ssize_t tx_bytes; 532 if (abuf == NULL) { 533 tx_bytes = zfs_uio_resid(uio); 534 zfs_uio_fault_disable(uio, B_TRUE); 535 error = dmu_write_uio_dbuf(sa_get_db(zp->z_sa_hdl), 536 uio, nbytes, tx); 537 zfs_uio_fault_disable(uio, B_FALSE); 538#ifdef __linux__ 539 if (error == EFAULT) { 540 dmu_tx_commit(tx); 541 /* 542 * Account for partial writes before 543 * continuing the loop. 544 * Update needs to occur before the next 545 * zfs_uio_prefaultpages, or prefaultpages may 546 * error, and we may break the loop early. 547 */ 548 if (tx_bytes != zfs_uio_resid(uio)) 549 n -= tx_bytes - zfs_uio_resid(uio); 550 if (zfs_uio_prefaultpages(MIN(n, max_blksz), 551 uio)) { 552 break; 553 } 554 continue; 555 } 556#endif 557 if (error != 0) { 558 dmu_tx_commit(tx); 559 break; 560 } 561 tx_bytes -= zfs_uio_resid(uio); 562 } else { 563 /* Implied by abuf != NULL: */ 564 ASSERT3S(n, >=, max_blksz); 565 ASSERT0(P2PHASE(woff, max_blksz)); 566 /* 567 * We can simplify nbytes to MIN(n, max_blksz) since 568 * P2PHASE(woff, max_blksz) is 0, and knowing 569 * n >= max_blksz lets us simplify further: 570 */ 571 ASSERT3S(nbytes, ==, max_blksz); 572 /* 573 * Thus, we're writing a full block at a block-aligned 574 * offset and extending the file past EOF. 575 * 576 * dmu_assign_arcbuf_by_dbuf() will directly assign the 577 * arc buffer to a dbuf. 578 */ 579 error = dmu_assign_arcbuf_by_dbuf( 580 sa_get_db(zp->z_sa_hdl), woff, abuf, tx); 581 if (error != 0) { 582 dmu_return_arcbuf(abuf); 583 dmu_tx_commit(tx); 584 break; 585 } 586 ASSERT3S(nbytes, <=, zfs_uio_resid(uio)); 587 zfs_uioskip(uio, nbytes); 588 tx_bytes = nbytes; 589 } 590 if (tx_bytes && zn_has_cached_data(zp) && 591 !(ioflag & O_DIRECT)) { 592 update_pages(zp, woff, tx_bytes, zfsvfs->z_os); 593 } 594 595 /* 596 * If we made no progress, we're done. If we made even 597 * partial progress, update the znode and ZIL accordingly. 598 */ 599 if (tx_bytes == 0) { 600 (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs), 601 (void *)&zp->z_size, sizeof (uint64_t), tx); 602 dmu_tx_commit(tx); 603 ASSERT(error != 0); 604 break; 605 } 606 607 /* 608 * Clear Set-UID/Set-GID bits on successful write if not 609 * privileged and at least one of the execute bits is set. 610 * 611 * It would be nice to do this after all writes have 612 * been done, but that would still expose the ISUID/ISGID 613 * to another app after the partial write is committed. 614 * 615 * Note: we don't call zfs_fuid_map_id() here because 616 * user 0 is not an ephemeral uid. 617 */ 618 mutex_enter(&zp->z_acl_lock); 619 if ((zp->z_mode & (S_IXUSR | (S_IXUSR >> 3) | 620 (S_IXUSR >> 6))) != 0 && 621 (zp->z_mode & (S_ISUID | S_ISGID)) != 0 && 622 secpolicy_vnode_setid_retain(zp, cr, 623 ((zp->z_mode & S_ISUID) != 0 && uid == 0)) != 0) { 624 uint64_t newmode; 625 zp->z_mode &= ~(S_ISUID | S_ISGID); 626 newmode = zp->z_mode; 627 (void) sa_update(zp->z_sa_hdl, SA_ZPL_MODE(zfsvfs), 628 (void *)&newmode, sizeof (uint64_t), tx); 629 } 630 mutex_exit(&zp->z_acl_lock); 631 632 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime); 633 634 /* 635 * Update the file size (zp_size) if it has changed; 636 * account for possible concurrent updates. 637 */ 638 while ((end_size = zp->z_size) < zfs_uio_offset(uio)) { 639 (void) atomic_cas_64(&zp->z_size, end_size, 640 zfs_uio_offset(uio)); 641 ASSERT(error == 0); 642 } 643 /* 644 * If we are replaying and eof is non zero then force 645 * the file size to the specified eof. Note, there's no 646 * concurrency during replay. 647 */ 648 if (zfsvfs->z_replay && zfsvfs->z_replay_eof != 0) 649 zp->z_size = zfsvfs->z_replay_eof; 650 651 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx); 652 653 zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag, 654 NULL, NULL); 655 dmu_tx_commit(tx); 656 657 if (error != 0) 658 break; 659 ASSERT3S(tx_bytes, ==, nbytes); 660 n -= nbytes; 661 662 if (n > 0) { 663 if (zfs_uio_prefaultpages(MIN(n, max_blksz), uio)) { 664 error = SET_ERROR(EFAULT); 665 break; 666 } 667 } 668 } 669 670 zfs_znode_update_vfs(zp); 671 zfs_rangelock_exit(lr); 672 673 /* 674 * If we're in replay mode, or we made no progress, or the 675 * uio data is inaccessible return an error. Otherwise, it's 676 * at least a partial write, so it's successful. 677 */ 678 if (zfsvfs->z_replay || zfs_uio_resid(uio) == start_resid || 679 error == EFAULT) { 680 ZFS_EXIT(zfsvfs); 681 return (error); 682 } 683 684 if (ioflag & (O_SYNC | O_DSYNC) || 685 zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS) 686 zil_commit(zilog, zp->z_id); 687 688 const int64_t nwritten = start_resid - zfs_uio_resid(uio); 689 dataset_kstats_update_write_kstats(&zfsvfs->z_kstat, nwritten); 690 task_io_account_write(nwritten); 691 692 ZFS_EXIT(zfsvfs); 693 return (0); 694} 695 696/*ARGSUSED*/ 697int 698zfs_getsecattr(znode_t *zp, vsecattr_t *vsecp, int flag, cred_t *cr) 699{ 700 zfsvfs_t *zfsvfs = ZTOZSB(zp); 701 int error; 702 boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE; 703 704 ZFS_ENTER(zfsvfs); 705 ZFS_VERIFY_ZP(zp); 706 error = zfs_getacl(zp, vsecp, skipaclchk, cr); 707 ZFS_EXIT(zfsvfs); 708 709 return (error); 710} 711 712/*ARGSUSED*/ 713int 714zfs_setsecattr(znode_t *zp, vsecattr_t *vsecp, int flag, cred_t *cr) 715{ 716 zfsvfs_t *zfsvfs = ZTOZSB(zp); 717 int error; 718 boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE; 719 zilog_t *zilog = zfsvfs->z_log; 720 721 ZFS_ENTER(zfsvfs); 722 ZFS_VERIFY_ZP(zp); 723 724 error = zfs_setacl(zp, vsecp, skipaclchk, cr); 725 726 if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS) 727 zil_commit(zilog, 0); 728 729 ZFS_EXIT(zfsvfs); 730 return (error); 731} 732 733#ifdef ZFS_DEBUG 734static int zil_fault_io = 0; 735#endif 736 737static void zfs_get_done(zgd_t *zgd, int error); 738 739/* 740 * Get data to generate a TX_WRITE intent log record. 741 */ 742int 743zfs_get_data(void *arg, uint64_t gen, lr_write_t *lr, char *buf, 744 struct lwb *lwb, zio_t *zio) 745{ 746 zfsvfs_t *zfsvfs = arg; 747 objset_t *os = zfsvfs->z_os; 748 znode_t *zp; 749 uint64_t object = lr->lr_foid; 750 uint64_t offset = lr->lr_offset; 751 uint64_t size = lr->lr_length; 752 dmu_buf_t *db; 753 zgd_t *zgd; 754 int error = 0; 755 uint64_t zp_gen; 756 757 ASSERT3P(lwb, !=, NULL); 758 ASSERT3P(zio, !=, NULL); 759 ASSERT3U(size, !=, 0); 760 761 /* 762 * Nothing to do if the file has been removed 763 */ 764 if (zfs_zget(zfsvfs, object, &zp) != 0) 765 return (SET_ERROR(ENOENT)); 766 if (zp->z_unlinked) { 767 /* 768 * Release the vnode asynchronously as we currently have the 769 * txg stopped from syncing. 770 */ 771 zfs_zrele_async(zp); 772 return (SET_ERROR(ENOENT)); 773 } 774 /* check if generation number matches */ 775 if (sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs), &zp_gen, 776 sizeof (zp_gen)) != 0) { 777 zfs_zrele_async(zp); 778 return (SET_ERROR(EIO)); 779 } 780 if (zp_gen != gen) { 781 zfs_zrele_async(zp); 782 return (SET_ERROR(ENOENT)); 783 } 784 785 zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP); 786 zgd->zgd_lwb = lwb; 787 zgd->zgd_private = zp; 788 789 /* 790 * Write records come in two flavors: immediate and indirect. 791 * For small writes it's cheaper to store the data with the 792 * log record (immediate); for large writes it's cheaper to 793 * sync the data and get a pointer to it (indirect) so that 794 * we don't have to write the data twice. 795 */ 796 if (buf != NULL) { /* immediate write */ 797 zgd->zgd_lr = zfs_rangelock_enter(&zp->z_rangelock, 798 offset, size, RL_READER); 799 /* test for truncation needs to be done while range locked */ 800 if (offset >= zp->z_size) { 801 error = SET_ERROR(ENOENT); 802 } else { 803 error = dmu_read(os, object, offset, size, buf, 804 DMU_READ_NO_PREFETCH); 805 } 806 ASSERT(error == 0 || error == ENOENT); 807 } else { /* indirect write */ 808 /* 809 * Have to lock the whole block to ensure when it's 810 * written out and its checksum is being calculated 811 * that no one can change the data. We need to re-check 812 * blocksize after we get the lock in case it's changed! 813 */ 814 for (;;) { 815 uint64_t blkoff; 816 size = zp->z_blksz; 817 blkoff = ISP2(size) ? P2PHASE(offset, size) : offset; 818 offset -= blkoff; 819 zgd->zgd_lr = zfs_rangelock_enter(&zp->z_rangelock, 820 offset, size, RL_READER); 821 if (zp->z_blksz == size) 822 break; 823 offset += blkoff; 824 zfs_rangelock_exit(zgd->zgd_lr); 825 } 826 /* test for truncation needs to be done while range locked */ 827 if (lr->lr_offset >= zp->z_size) 828 error = SET_ERROR(ENOENT); 829#ifdef ZFS_DEBUG 830 if (zil_fault_io) { 831 error = SET_ERROR(EIO); 832 zil_fault_io = 0; 833 } 834#endif 835 if (error == 0) 836 error = dmu_buf_hold(os, object, offset, zgd, &db, 837 DMU_READ_NO_PREFETCH); 838 839 if (error == 0) { 840 blkptr_t *bp = &lr->lr_blkptr; 841 842 zgd->zgd_db = db; 843 zgd->zgd_bp = bp; 844 845 ASSERT(db->db_offset == offset); 846 ASSERT(db->db_size == size); 847 848 error = dmu_sync(zio, lr->lr_common.lrc_txg, 849 zfs_get_done, zgd); 850 ASSERT(error || lr->lr_length <= size); 851 852 /* 853 * On success, we need to wait for the write I/O 854 * initiated by dmu_sync() to complete before we can 855 * release this dbuf. We will finish everything up 856 * in the zfs_get_done() callback. 857 */ 858 if (error == 0) 859 return (0); 860 861 if (error == EALREADY) { 862 lr->lr_common.lrc_txtype = TX_WRITE2; 863 /* 864 * TX_WRITE2 relies on the data previously 865 * written by the TX_WRITE that caused 866 * EALREADY. We zero out the BP because 867 * it is the old, currently-on-disk BP. 868 */ 869 zgd->zgd_bp = NULL; 870 BP_ZERO(bp); 871 error = 0; 872 } 873 } 874 } 875 876 zfs_get_done(zgd, error); 877 878 return (error); 879} 880 881 882/* ARGSUSED */ 883static void 884zfs_get_done(zgd_t *zgd, int error) 885{ 886 znode_t *zp = zgd->zgd_private; 887 888 if (zgd->zgd_db) 889 dmu_buf_rele(zgd->zgd_db, zgd); 890 891 zfs_rangelock_exit(zgd->zgd_lr); 892 893 /* 894 * Release the vnode asynchronously as we currently have the 895 * txg stopped from syncing. 896 */ 897 zfs_zrele_async(zp); 898 899 kmem_free(zgd, sizeof (zgd_t)); 900} 901 902EXPORT_SYMBOL(zfs_access); 903EXPORT_SYMBOL(zfs_fsync); 904EXPORT_SYMBOL(zfs_holey); 905EXPORT_SYMBOL(zfs_read); 906EXPORT_SYMBOL(zfs_write); 907EXPORT_SYMBOL(zfs_getsecattr); 908EXPORT_SYMBOL(zfs_setsecattr); 909 910ZFS_MODULE_PARAM(zfs_vnops, zfs_vnops_, read_chunk_size, ULONG, ZMOD_RW, 911 "Bytes to read per chunk"); 912