nfs_bio.c revision 1.15
1 /* $NetBSD: nfs_bio.c,v 1.15 1994/06/29 06:42:05 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Rick Macklem at The University of Guelph. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)nfs_bio.c 8.5 (Berkeley) 1/4/94 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/resourcevar.h> 44 #include <sys/proc.h> 45 #include <sys/buf.h> 46 #include <sys/vnode.h> 47 #include <sys/trace.h> 48 #include <sys/mount.h> 49 #include <sys/kernel.h> 50 51 #include <vm/vm.h> 52 53 #include <nfs/nfsnode.h> 54 #include <nfs/rpcv2.h> 55 #include <nfs/nfsv2.h> 56 #include <nfs/nfs.h> 57 #include <nfs/nfsmount.h> 58 #include <nfs/nqnfs.h> 59 60 struct buf *incore(), *nfs_getcacheblk(); 61 extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON]; 62 extern int nfs_numasync; 63 64 /* 65 * Vnode op for read using bio 66 * Any similarity to readip() is purely coincidental 67 */ 68 nfs_bioread(vp, uio, ioflag, cred) 69 register struct vnode *vp; 70 register struct uio *uio; 71 int ioflag; 72 struct ucred *cred; 73 { 74 register struct nfsnode *np = VTONFS(vp); 75 register int biosize, diff; 76 struct buf *bp, *rabp; 77 struct vattr vattr; 78 struct proc *p; 79 struct nfsmount *nmp; 80 daddr_t lbn, bn, rabn; 81 caddr_t baddr; 82 int got_buf, nra, error = 0, n, on, not_readin; 83 84 #ifdef lint 85 ioflag = ioflag; 86 #endif /* lint */ 87 #ifdef DIAGNOSTIC 88 if (uio->uio_rw != UIO_READ) 89 panic("nfs_read mode"); 90 #endif 91 if (uio->uio_resid == 0) 92 return (0); 93 if (uio->uio_offset < 0 && vp->v_type != VDIR) 94 return (EINVAL); 95 nmp = VFSTONFS(vp->v_mount); 96 biosize = nmp->nm_rsize; 97 p = uio->uio_procp; 98 /* 99 * For nfs, cache consistency can only be maintained approximately. 100 * Although RFC1094 does not specify the criteria, the following is 101 * believed to be compatible with the reference port. 102 * For nqnfs, full cache consistency is maintained within the loop. 103 * For nfs: 104 * If the file's modify time on the server has changed since the 105 * last read rpc or you have written to the file, 106 * you may have lost data cache consistency with the 107 * server, so flush all of the file's data out of the cache. 108 * Then force a getattr rpc to ensure that you have up to date 109 * attributes. 110 * The mount flag NFSMNT_MYWRITE says "Assume that my writes are 111 * the ones changing the modify time. 112 * NB: This implies that cache data can be read when up to 113 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 114 * attributes this could be forced by setting n_attrstamp to 0 before 115 * the VOP_GETATTR() call. 116 */ 117 if ((nmp->nm_flag & NFSMNT_NQNFS) == 0 && vp->v_type != VLNK) { 118 if (np->n_flag & NMODIFIED) { 119 if ((nmp->nm_flag & NFSMNT_MYWRITE) == 0 || 120 vp->v_type != VREG) { 121 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 122 return (error); 123 } 124 np->n_attrstamp = 0; 125 np->n_direofoffset = 0; 126 if (error = VOP_GETATTR(vp, &vattr, cred, p)) 127 return (error); 128 np->n_mtime = vattr.va_mtime.ts_sec; 129 } else { 130 if (error = VOP_GETATTR(vp, &vattr, cred, p)) 131 return (error); 132 if (np->n_mtime != vattr.va_mtime.ts_sec) { 133 np->n_direofoffset = 0; 134 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 135 return (error); 136 np->n_mtime = vattr.va_mtime.ts_sec; 137 } 138 } 139 } 140 do { 141 142 /* 143 * Get a valid lease. If cached data is stale, flush it. 144 */ 145 if (nmp->nm_flag & NFSMNT_NQNFS) { 146 if (NQNFS_CKINVALID(vp, np, NQL_READ)) { 147 do { 148 error = nqnfs_getlease(vp, NQL_READ, cred, p); 149 } while (error == NQNFS_EXPIRED); 150 if (error) 151 return (error); 152 if (np->n_lrev != np->n_brev || 153 (np->n_flag & NQNFSNONCACHE) || 154 ((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) { 155 if (vp->v_type == VDIR) { 156 np->n_direofoffset = 0; 157 cache_purge(vp); 158 } 159 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 160 return (error); 161 np->n_brev = np->n_lrev; 162 } 163 } else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) { 164 np->n_direofoffset = 0; 165 cache_purge(vp); 166 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 167 return (error); 168 } 169 } 170 if (np->n_flag & NQNFSNONCACHE) { 171 switch (vp->v_type) { 172 case VREG: 173 error = nfs_readrpc(vp, uio, cred); 174 break; 175 case VLNK: 176 error = nfs_readlinkrpc(vp, uio, cred); 177 break; 178 case VDIR: 179 error = nfs_readdirrpc(vp, uio, cred); 180 break; 181 }; 182 return (error); 183 } 184 baddr = (caddr_t)0; 185 switch (vp->v_type) { 186 case VREG: 187 nfsstats.biocache_reads++; 188 lbn = uio->uio_offset / biosize; 189 on = uio->uio_offset & (biosize-1); 190 bn = lbn * (biosize / DEV_BSIZE); 191 not_readin = 1; 192 193 /* 194 * Start the read ahead(s), as required. 195 */ 196 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 197 lbn == vp->v_lastr + 1) { 198 for (nra = 0; nra < nmp->nm_readahead && 199 (lbn + 1 + nra) * biosize < np->n_size; nra++) { 200 rabn = (lbn + 1 + nra) * (biosize / DEV_BSIZE); 201 if (!incore(vp, rabn)) { 202 rabp = nfs_getcacheblk(vp, rabn, biosize, p); 203 if (!rabp) 204 return (EINTR); 205 if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) { 206 rabp->b_flags |= (B_READ | B_ASYNC); 207 if (nfs_asyncio(rabp, cred)) { 208 rabp->b_flags |= B_INVAL; 209 brelse(rabp); 210 } 211 } 212 } 213 } 214 } 215 216 /* 217 * If the block is in the cache and has the required data 218 * in a valid region, just copy it out. 219 * Otherwise, get the block and write back/read in, 220 * as required. 221 */ 222 if ((bp = incore(vp, bn)) && 223 (bp->b_flags & (B_BUSY | B_WRITEINPROG)) == 224 (B_BUSY | B_WRITEINPROG)) 225 got_buf = 0; 226 else { 227 again: 228 bp = nfs_getcacheblk(vp, bn, biosize, p); 229 if (!bp) 230 return (EINTR); 231 got_buf = 1; 232 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) { 233 bp->b_flags |= B_READ; 234 not_readin = 0; 235 if (error = nfs_doio(bp, cred, p)) { 236 brelse(bp); 237 return (error); 238 } 239 } 240 } 241 n = min((unsigned)(biosize - on), uio->uio_resid); 242 diff = np->n_size - uio->uio_offset; 243 if (diff < n) 244 n = diff; 245 if (not_readin && n > 0) { 246 if (on < bp->b_validoff || (on + n) > bp->b_validend) { 247 if (!got_buf) { 248 bp = nfs_getcacheblk(vp, bn, biosize, p); 249 if (!bp) 250 return (EINTR); 251 got_buf = 1; 252 } 253 bp->b_flags |= B_INVAL; 254 if (bp->b_dirtyend > 0) { 255 if ((bp->b_flags & B_DELWRI) == 0) 256 panic("nfsbioread"); 257 if (VOP_BWRITE(bp) == EINTR) 258 return (EINTR); 259 } else 260 brelse(bp); 261 goto again; 262 } 263 } 264 vp->v_lastr = lbn; 265 diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on); 266 if (diff < n) 267 n = diff; 268 break; 269 case VLNK: 270 nfsstats.biocache_readlinks++; 271 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p); 272 if (!bp) 273 return (EINTR); 274 if ((bp->b_flags & B_DONE) == 0) { 275 bp->b_flags |= B_READ; 276 if (error = nfs_doio(bp, cred, p)) { 277 brelse(bp); 278 return (error); 279 } 280 } 281 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 282 got_buf = 1; 283 on = 0; 284 break; 285 case VDIR: 286 nfsstats.biocache_readdirs++; 287 bn = (daddr_t)uio->uio_offset; 288 bp = nfs_getcacheblk(vp, bn, NFS_DIRBLKSIZ, p); 289 if (!bp) 290 return (EINTR); 291 if ((bp->b_flags & B_DONE) == 0) { 292 bp->b_flags |= B_READ; 293 if (error = nfs_doio(bp, cred, p)) { 294 brelse(bp); 295 return (error); 296 } 297 } 298 299 /* 300 * If not eof and read aheads are enabled, start one. 301 * (You need the current block first, so that you have the 302 * directory offset cookie of the next block. 303 */ 304 rabn = bp->b_blkno; 305 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 306 rabn != 0 && rabn != np->n_direofoffset && 307 !incore(vp, rabn)) { 308 rabp = nfs_getcacheblk(vp, rabn, NFS_DIRBLKSIZ, p); 309 if (rabp) { 310 if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) { 311 rabp->b_flags |= (B_READ | B_ASYNC); 312 if (nfs_asyncio(rabp, cred)) { 313 rabp->b_flags |= B_INVAL; 314 brelse(rabp); 315 } 316 } 317 } 318 } 319 on = 0; 320 n = min(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid); 321 got_buf = 1; 322 break; 323 }; 324 325 if (n > 0) { 326 if (!baddr) 327 baddr = bp->b_data; 328 error = uiomove(baddr + on, (int)n, uio); 329 } 330 switch (vp->v_type) { 331 case VREG: 332 if (n + on == biosize || uio->uio_offset == np->n_size) 333 bp->b_flags |= B_AGE; 334 break; 335 case VLNK: 336 n = 0; 337 break; 338 case VDIR: 339 uio->uio_offset = bp->b_blkno; 340 break; 341 }; 342 if (got_buf) 343 brelse(bp); 344 } while (error == 0 && uio->uio_resid > 0 && n > 0); 345 return (error); 346 } 347 348 /* 349 * Vnode op for write using bio 350 */ 351 nfs_write(ap) 352 struct vop_write_args /* { 353 struct vnode *a_vp; 354 struct uio *a_uio; 355 int a_ioflag; 356 struct ucred *a_cred; 357 } */ *ap; 358 { 359 register int biosize; 360 register struct uio *uio = ap->a_uio; 361 struct proc *p = uio->uio_procp; 362 register struct vnode *vp = ap->a_vp; 363 struct nfsnode *np = VTONFS(vp); 364 register struct ucred *cred = ap->a_cred; 365 int ioflag = ap->a_ioflag; 366 struct buf *bp; 367 struct vattr vattr; 368 struct nfsmount *nmp; 369 daddr_t lbn, bn; 370 int n, on, error = 0; 371 372 #ifdef DIAGNOSTIC 373 if (uio->uio_rw != UIO_WRITE) 374 panic("nfs_write mode"); 375 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 376 panic("nfs_write proc"); 377 #endif 378 if (vp->v_type != VREG) 379 return (EIO); 380 if (np->n_flag & NWRITEERR) { 381 np->n_flag &= ~NWRITEERR; 382 return (np->n_error); 383 } 384 if (ioflag & (IO_APPEND | IO_SYNC)) { 385 if (np->n_flag & NMODIFIED) { 386 np->n_attrstamp = 0; 387 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 388 return (error); 389 } 390 if (ioflag & IO_APPEND) { 391 np->n_attrstamp = 0; 392 if (error = VOP_GETATTR(vp, &vattr, cred, p)) 393 return (error); 394 uio->uio_offset = np->n_size; 395 } 396 } 397 nmp = VFSTONFS(vp->v_mount); 398 if (uio->uio_offset < 0) 399 return (EINVAL); 400 if (uio->uio_resid == 0) 401 return (0); 402 /* 403 * Maybe this should be above the vnode op call, but so long as 404 * file servers have no limits, i don't think it matters 405 */ 406 if (p && uio->uio_offset + uio->uio_resid > 407 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 408 psignal(p, SIGXFSZ); 409 return (EFBIG); 410 } 411 /* 412 * I use nm_rsize, not nm_wsize so that all buffer cache blocks 413 * will be the same size within a filesystem. nfs_writerpc will 414 * still use nm_wsize when sizing the rpc's. 415 */ 416 biosize = nmp->nm_rsize; 417 do { 418 419 /* 420 * Check for a valid write lease. 421 * If non-cachable, just do the rpc 422 */ 423 if ((nmp->nm_flag & NFSMNT_NQNFS) && 424 NQNFS_CKINVALID(vp, np, NQL_WRITE)) { 425 do { 426 error = nqnfs_getlease(vp, NQL_WRITE, cred, p); 427 } while (error == NQNFS_EXPIRED); 428 if (error) 429 return (error); 430 if (np->n_lrev != np->n_brev || 431 (np->n_flag & NQNFSNONCACHE)) { 432 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 433 return (error); 434 np->n_brev = np->n_lrev; 435 } 436 } 437 if (np->n_flag & NQNFSNONCACHE) 438 return (nfs_writerpc(vp, uio, cred, ioflag)); 439 nfsstats.biocache_writes++; 440 lbn = uio->uio_offset / biosize; 441 on = uio->uio_offset & (biosize-1); 442 n = min((unsigned)(biosize - on), uio->uio_resid); 443 bn = lbn * (biosize / DEV_BSIZE); 444 again: 445 bp = nfs_getcacheblk(vp, bn, biosize, p); 446 if (!bp) 447 return (EINTR); 448 if (bp->b_wcred == NOCRED) { 449 crhold(cred); 450 bp->b_wcred = cred; 451 } 452 np->n_flag |= NMODIFIED; 453 if (uio->uio_offset + n > np->n_size) { 454 np->n_size = uio->uio_offset + n; 455 vnode_pager_setsize(vp, (u_long)np->n_size); 456 } 457 458 /* 459 * If the new write will leave a contiguous dirty 460 * area, just update the b_dirtyoff and b_dirtyend, 461 * otherwise force a write rpc of the old dirty area. 462 */ 463 if (bp->b_dirtyend > 0 && 464 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 465 bp->b_proc = p; 466 if (VOP_BWRITE(bp) == EINTR) 467 return (EINTR); 468 goto again; 469 } 470 471 /* 472 * Check for valid write lease and get one as required. 473 * In case getblk() and/or bwrite() delayed us. 474 */ 475 if ((nmp->nm_flag & NFSMNT_NQNFS) && 476 NQNFS_CKINVALID(vp, np, NQL_WRITE)) { 477 do { 478 error = nqnfs_getlease(vp, NQL_WRITE, cred, p); 479 } while (error == NQNFS_EXPIRED); 480 if (error) { 481 brelse(bp); 482 return (error); 483 } 484 if (np->n_lrev != np->n_brev || 485 (np->n_flag & NQNFSNONCACHE)) { 486 brelse(bp); 487 if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1)) 488 return (error); 489 np->n_brev = np->n_lrev; 490 goto again; 491 } 492 } 493 if (error = uiomove((char *)bp->b_data + on, n, uio)) { 494 bp->b_flags |= B_ERROR; 495 brelse(bp); 496 return (error); 497 } 498 if (bp->b_dirtyend > 0) { 499 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 500 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 501 } else { 502 bp->b_dirtyoff = on; 503 bp->b_dirtyend = on + n; 504 } 505 #ifndef notdef 506 if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff || 507 bp->b_validoff > bp->b_dirtyend) { 508 bp->b_validoff = bp->b_dirtyoff; 509 bp->b_validend = bp->b_dirtyend; 510 } else { 511 bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff); 512 bp->b_validend = max(bp->b_validend, bp->b_dirtyend); 513 } 514 #else 515 bp->b_validoff = bp->b_dirtyoff; 516 bp->b_validend = bp->b_dirtyend; 517 #endif 518 if (ioflag & IO_APPEND) 519 bp->b_flags |= B_APPENDWRITE; 520 521 /* 522 * If the lease is non-cachable or IO_SYNC do bwrite(). 523 */ 524 if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) { 525 bp->b_proc = p; 526 if (error = VOP_BWRITE(bp)) 527 return (error); 528 } else if ((n + on) == biosize && 529 (nmp->nm_flag & NFSMNT_NQNFS) == 0) { 530 bp->b_proc = (struct proc *)0; 531 bawrite(bp); 532 } else 533 bdwrite(bp); 534 } while (uio->uio_resid > 0 && n > 0); 535 return (0); 536 } 537 538 /* 539 * Get an nfs cache block. 540 * Allocate a new one if the block isn't currently in the cache 541 * and return the block marked busy. If the calling process is 542 * interrupted by a signal for an interruptible mount point, return 543 * NULL. 544 */ 545 struct buf * 546 nfs_getcacheblk(vp, bn, size, p) 547 struct vnode *vp; 548 daddr_t bn; 549 int size; 550 struct proc *p; 551 { 552 register struct buf *bp; 553 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 554 555 if (nmp->nm_flag & NFSMNT_INT) { 556 bp = getblk(vp, bn, size, PCATCH, 0); 557 while (bp == (struct buf *)0) { 558 if (nfs_sigintr(nmp, (struct nfsreq *)0, p)) 559 return ((struct buf *)0); 560 bp = getblk(vp, bn, size, 0, 2 * hz); 561 } 562 } else 563 bp = getblk(vp, bn, size, 0, 0); 564 return (bp); 565 } 566 567 /* 568 * Flush and invalidate all dirty buffers. If another process is already 569 * doing the flush, just wait for completion. 570 */ 571 nfs_vinvalbuf(vp, flags, cred, p, intrflg) 572 struct vnode *vp; 573 int flags; 574 struct ucred *cred; 575 struct proc *p; 576 int intrflg; 577 { 578 register struct nfsnode *np = VTONFS(vp); 579 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 580 int error = 0, slpflag, slptimeo; 581 582 if ((nmp->nm_flag & NFSMNT_INT) == 0) 583 intrflg = 0; 584 if (intrflg) { 585 slpflag = PCATCH; 586 slptimeo = 2 * hz; 587 } else { 588 slpflag = 0; 589 slptimeo = 0; 590 } 591 /* 592 * First wait for any other process doing a flush to complete. 593 */ 594 while (np->n_flag & NFLUSHINPROG) { 595 np->n_flag |= NFLUSHWANT; 596 error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval", 597 slptimeo); 598 if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) 599 return (EINTR); 600 } 601 602 /* 603 * Now, flush as required. 604 */ 605 np->n_flag |= NFLUSHINPROG; 606 error = vinvalbuf(vp, flags, cred, p, slpflag, 0); 607 while (error) { 608 if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) { 609 np->n_flag &= ~NFLUSHINPROG; 610 if (np->n_flag & NFLUSHWANT) { 611 np->n_flag &= ~NFLUSHWANT; 612 wakeup((caddr_t)&np->n_flag); 613 } 614 return (EINTR); 615 } 616 error = vinvalbuf(vp, flags, cred, p, 0, slptimeo); 617 } 618 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); 619 if (np->n_flag & NFLUSHWANT) { 620 np->n_flag &= ~NFLUSHWANT; 621 wakeup((caddr_t)&np->n_flag); 622 } 623 return (0); 624 } 625 626 /* 627 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 628 * This is mainly to avoid queueing async I/O requests when the nfsiods 629 * are all hung on a dead server. 630 */ 631 nfs_asyncio(bp, cred) 632 register struct buf *bp; 633 struct ucred *cred; 634 { 635 register int i; 636 637 if (nfs_numasync == 0) 638 return (EIO); 639 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 640 if (nfs_iodwant[i]) { 641 if (bp->b_flags & B_READ) { 642 if (bp->b_rcred == NOCRED && cred != NOCRED) { 643 crhold(cred); 644 bp->b_rcred = cred; 645 } 646 } else { 647 if (bp->b_wcred == NOCRED && cred != NOCRED) { 648 crhold(cred); 649 bp->b_wcred = cred; 650 } 651 } 652 653 TAILQ_INSERT_TAIL(&nfs_bufq, bp, b_freelist); 654 nfs_iodwant[i] = (struct proc *)0; 655 wakeup((caddr_t)&nfs_iodwant[i]); 656 return (0); 657 } 658 return (EIO); 659 } 660 661 /* 662 * Do an I/O operation to/from a cache block. This may be called 663 * synchronously or from an nfsiod. 664 */ 665 int 666 nfs_doio(bp, cr, p) 667 register struct buf *bp; 668 struct cred *cr; 669 struct proc *p; 670 { 671 register struct uio *uiop; 672 register struct vnode *vp; 673 struct nfsnode *np; 674 struct nfsmount *nmp; 675 int error, diff, len; 676 struct uio uio; 677 struct iovec io; 678 679 vp = bp->b_vp; 680 np = VTONFS(vp); 681 nmp = VFSTONFS(vp->v_mount); 682 uiop = &uio; 683 uiop->uio_iov = &io; 684 uiop->uio_iovcnt = 1; 685 uiop->uio_segflg = UIO_SYSSPACE; 686 uiop->uio_procp = p; 687 688 /* 689 * Historically, paging was done with physio, but no more... 690 */ 691 if (bp->b_flags & B_PHYS) { 692 /* 693 * ...though reading /dev/drum still gets us here. 694 */ 695 io.iov_len = uiop->uio_resid = bp->b_bcount; 696 /* mapping was done by vmapbuf() */ 697 io.iov_base = bp->b_data; 698 uiop->uio_offset = bp->b_blkno * DEV_BSIZE; 699 if (bp->b_flags & B_READ) { 700 uiop->uio_rw = UIO_READ; 701 nfsstats.read_physios++; 702 error = nfs_readrpc(vp, uiop, cr); 703 } else { 704 uiop->uio_rw = UIO_WRITE; 705 nfsstats.write_physios++; 706 error = nfs_writerpc(vp, uiop, cr); 707 } 708 if (error) { 709 bp->b_flags |= B_ERROR; 710 bp->b_error = error; 711 } 712 } else if (bp->b_flags & B_READ) { 713 io.iov_len = uiop->uio_resid = bp->b_bcount; 714 io.iov_base = bp->b_data; 715 uiop->uio_rw = UIO_READ; 716 switch (vp->v_type) { 717 case VREG: 718 uiop->uio_offset = bp->b_blkno * DEV_BSIZE; 719 nfsstats.read_bios++; 720 error = nfs_readrpc(vp, uiop, cr); 721 if (!error) { 722 bp->b_validoff = 0; 723 if (uiop->uio_resid) { 724 /* 725 * If len > 0, there is a hole in the file and 726 * no writes after the hole have been pushed to 727 * the server yet. 728 * Just zero fill the rest of the valid area. 729 */ 730 diff = bp->b_bcount - uiop->uio_resid; 731 len = np->n_size - (bp->b_blkno * DEV_BSIZE 732 + diff); 733 if (len > 0) { 734 len = min(len, uiop->uio_resid); 735 bzero((char *)bp->b_data + diff, len); 736 bp->b_validend = diff + len; 737 } else 738 bp->b_validend = diff; 739 } else 740 bp->b_validend = bp->b_bcount; 741 } 742 if (p && (vp->v_flag & VTEXT) && 743 (((nmp->nm_flag & NFSMNT_NQNFS) && 744 np->n_lrev != np->n_brev) || 745 (!(nmp->nm_flag & NFSMNT_NQNFS) && 746 np->n_mtime != np->n_vattr.va_mtime.ts_sec))) { 747 uprintf("Process killed due to text file modification\n"); 748 psignal(p, SIGKILL); 749 p->p_holdcnt++; 750 } 751 break; 752 case VLNK: 753 uiop->uio_offset = 0; 754 nfsstats.readlink_bios++; 755 error = nfs_readlinkrpc(vp, uiop, cr); 756 break; 757 case VDIR: 758 uiop->uio_offset = bp->b_lblkno; 759 nfsstats.readdir_bios++; 760 if (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NQNFS) 761 error = nfs_readdirlookrpc(vp, uiop, cr); 762 else 763 error = nfs_readdirrpc(vp, uiop, cr); 764 /* 765 * Save offset cookie in b_blkno. 766 */ 767 bp->b_blkno = uiop->uio_offset; 768 break; 769 }; 770 if (error) { 771 bp->b_flags |= B_ERROR; 772 bp->b_error = error; 773 } 774 } else { 775 io.iov_len = uiop->uio_resid = bp->b_dirtyend 776 - bp->b_dirtyoff; 777 uiop->uio_offset = (bp->b_blkno * DEV_BSIZE) 778 + bp->b_dirtyoff; 779 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 780 uiop->uio_rw = UIO_WRITE; 781 nfsstats.write_bios++; 782 if (bp->b_flags & B_APPENDWRITE) 783 error = nfs_writerpc(vp, uiop, cr, IO_APPEND); 784 else 785 error = nfs_writerpc(vp, uiop, cr, 0); 786 bp->b_flags &= ~(B_WRITEINPROG | B_APPENDWRITE); 787 788 /* 789 * For an interrupted write, the buffer is still valid and the 790 * write hasn't been pushed to the server yet, so we can't set 791 * B_ERROR and report the interruption by setting B_EINTR. For 792 * the B_ASYNC case, B_EINTR is not relevant, so the rpc attempt 793 * is essentially a noop. 794 */ 795 if (error == EINTR) { 796 bp->b_flags &= ~B_INVAL; 797 bp->b_flags |= B_DELWRI; 798 799 /* 800 * Since for the B_ASYNC case, nfs_bwrite() has reassigned the 801 * buffer to the clean list, we have to reassign it back to the 802 * dirty one. Ugh. 803 */ 804 if (bp->b_flags & B_ASYNC) 805 reassignbuf(bp, vp); 806 else 807 bp->b_flags |= B_EINTR; 808 } else { 809 if (error) { 810 bp->b_flags |= B_ERROR; 811 bp->b_error = np->n_error = error; 812 np->n_flag |= NWRITEERR; 813 } 814 bp->b_dirtyoff = bp->b_dirtyend = 0; 815 } 816 } 817 bp->b_resid = uiop->uio_resid; 818 biodone(bp); 819 return (error); 820 } 821
Indexes created Tue Oct 14 11:09:46 GMT 2025