Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/fs/nfsd/vfs.c
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1 #define MSNFS /* HACK HACK */ 2 /* 3 * linux/fs/nfsd/vfs.c 4 * 5 * File operations used by nfsd. Some of these have been ripped from 6 * other parts of the kernel because they weren't in ksyms.c, others 7 * are partial duplicates with added or changed functionality. 8 * 9 * Note that several functions dget() the dentry upon which they want 10 * to act, most notably those that create directory entries. Response 11 * dentry's are dput()'d if necessary in the release callback. 12 * So if you notice code paths that apparently fail to dput() the 13 * dentry, don't worry--they have been taken care of. 14 * 15 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 16 */ 17 18 #include <linux/config.h> 19 #include <linux/version.h> 20 #include <linux/string.h> 21 #include <linux/sched.h> 22 #include <linux/errno.h> 23 #include <linux/locks.h> 24 #include <linux/fs.h> 25 #include <linux/major.h> 26 #include <linux/ext2_fs.h> 27 #include <linux/proc_fs.h> 28 #include <linux/stat.h> 29 #include <linux/fcntl.h> 30 #include <linux/net.h> 31 #include <linux/unistd.h> 32 #include <linux/slab.h> 33 #include <linux/in.h> 34 #define __NO_VERSION__ 35 #include <linux/module.h> 36 37 #include <linux/sunrpc/svc.h> 38 #include <linux/nfsd/nfsd.h> 39 #ifdef CONFIG_NFSD_V3 40 #include <linux/nfs3.h> 41 #include <linux/nfsd/xdr3.h> 42 #endif /* CONFIG_NFSD_V3 */ 43 #include <linux/nfsd/nfsfh.h> 44 #include <linux/quotaops.h> 45 46 #include <asm/uaccess.h> 47 48 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 49 #define NFSD_PARANOIA 50 51 52 /* We must ignore files (but only files) which might have mandatory 53 * locks on them because there is no way to know if the accesser has 54 * the lock. 55 */ 56 #define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i)) 57 58 /* 59 * This is a cache of readahead params that help us choose the proper 60 * readahead strategy. Initially, we set all readahead parameters to 0 61 * and let the VFS handle things. 62 * If you increase the number of cached files very much, you'll need to 63 * add a hash table here. 64 */ 65 struct raparms { 66 struct raparms *p_next; 67 unsigned int p_count; 68 ino_t p_ino; 69 dev_t p_dev; 70 unsigned long p_reada, 71 p_ramax, 72 p_raend, 73 p_ralen, 74 p_rawin; 75 }; 76 77 static struct raparms * raparml; 78 static struct raparms * raparm_cache; 79 80 /* 81 * Look up one component of a pathname. 82 * N.B. After this call _both_ fhp and resfh need an fh_put 83 * 84 * If the lookup would cross a mountpoint, and the mounted filesystem 85 * is exported to the client with NFSEXP_CROSSMNT, then the lookup is 86 * accepted as it stands and the mounted directory is 87 * returned. Otherwise the covered directory is returned. 88 * NOTE: this mountpoint crossing is not supported properly by all 89 * clients and is explicitly disallowed for NFSv3 90 * NeilBrown <neilb@cse.unsw.edu.au> 91 */ 92 int 93 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 94 int len, struct svc_fh *resfh) 95 { 96 struct svc_export *exp; 97 struct dentry *dparent; 98 struct dentry *dentry; 99 int err; 100 101 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 102 103 /* Obtain dentry and export. */ 104 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC); 105 if (err) 106 goto out; 107 108 dparent = fhp->fh_dentry; 109 exp = fhp->fh_export; 110 111 err = nfserr_acces; 112 113 /* Lookup the name, but don't follow links */ 114 if (isdotent(name, len)) { 115 if (len==1) 116 dentry = dget(dparent); 117 else if (dparent != exp->ex_dentry) 118 dentry = dget(dparent->d_parent); 119 else if (!EX_CROSSMNT(exp)) 120 dentry = dget(dparent); /* .. == . just like at / */ 121 else { 122 /* checking mountpoint crossing is very different when stepping up */ 123 struct svc_export *exp2 = NULL; 124 struct dentry *dp; 125 struct vfsmount *mnt = mntget(exp->ex_mnt); 126 dentry = dget(dparent); 127 while(follow_up(&mnt, &dentry)) 128 ; 129 dp = dget(dentry->d_parent); 130 dput(dentry); 131 dentry = dp; 132 for ( ; exp2 == NULL && dp->d_parent != dp; 133 dp=dp->d_parent) 134 exp2 = exp_get(exp->ex_client, dp->d_inode->i_dev, dp->d_inode->i_ino); 135 if (exp2==NULL) { 136 dput(dentry); 137 dentry = dget(dparent); 138 } else { 139 exp = exp2; 140 } 141 mntput(mnt); 142 } 143 } else { 144 fh_lock(fhp); 145 dentry = lookup_one_len(name, dparent, len); 146 err = PTR_ERR(dentry); 147 if (IS_ERR(dentry)) 148 goto out_nfserr; 149 /* 150 * check if we have crossed a mount point ... 151 */ 152 if (d_mountpoint(dentry)) { 153 struct svc_export *exp2 = NULL; 154 struct vfsmount *mnt = mntget(exp->ex_mnt); 155 struct dentry *mounts = dget(dentry); 156 while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)) 157 ; 158 exp2 = exp_get(rqstp->rq_client, 159 mounts->d_inode->i_dev, 160 mounts->d_inode->i_ino); 161 if (exp2 && EX_CROSSMNT(exp2)) { 162 /* successfully crossed mount point */ 163 exp = exp2; 164 dput(dentry); 165 dentry = mounts; 166 } else 167 dput(mounts); 168 mntput(mnt); 169 } 170 } 171 172 if (dentry->d_inode && dentry->d_inode->i_op && 173 dentry->d_inode->i_op->revalidate && 174 dentry->d_inode->i_op->revalidate(dentry)) 175 err = nfserr_noent; 176 else 177 err = fh_compose(resfh, exp, dentry, fhp); 178 if (!err && !dentry->d_inode) 179 err = nfserr_noent; 180 out: 181 return err; 182 183 out_nfserr: 184 err = nfserrno(err); 185 goto out; 186 } 187 188 /* 189 * Set various file attributes. 190 * N.B. After this call fhp needs an fh_put 191 */ 192 int 193 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 194 int check_guard, time_t guardtime) 195 { 196 struct dentry *dentry; 197 struct inode *inode; 198 int accmode = MAY_SATTR; 199 int ftype = 0; 200 int imode; 201 int err; 202 int size_change = 0; 203 204 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 205 accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE; 206 if (iap->ia_valid & ATTR_SIZE) 207 ftype = S_IFREG; 208 209 /* Get inode */ 210 err = fh_verify(rqstp, fhp, ftype, accmode); 211 if (err || !iap->ia_valid) 212 goto out; 213 214 dentry = fhp->fh_dentry; 215 inode = dentry->d_inode; 216 217 /* NFSv2 does not differentiate between "set-[ac]time-to-now" 218 * which only requires access, and "set-[ac]time-to-X" which 219 * requires ownership. 220 * So if it looks like it might be "set both to the same time which 221 * is close to now", and if inode_change_ok fails, then we 222 * convert to "set to now" instead of "set to explicit time" 223 * 224 * We only call inode_change_ok as the last test as technically 225 * it is not an interface that we should be using. It is only 226 * valid if the filesystem does not define it's own i_op->setattr. 227 */ 228 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 229 #define MAX_TOUCH_TIME_ERROR (30*60) 230 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET 231 && iap->ia_mtime == iap->ia_atime 232 ) { 233 /* Looks probable. Now just make sure time is in the right ballpark. 234 * Solaris, at least, doesn't seem to care what the time request is. 235 * We require it be within 30 minutes of now. 236 */ 237 time_t delta = iap->ia_atime - CURRENT_TIME; 238 if (delta<0) delta = -delta; 239 if (delta < MAX_TOUCH_TIME_ERROR && 240 inode_change_ok(inode, iap) != 0) { 241 /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME 242 * this will cause notify_change to set these times to "now" 243 */ 244 iap->ia_valid &= ~BOTH_TIME_SET; 245 } 246 } 247 248 /* The size case is special. It changes the file as well as the attributes. */ 249 if (iap->ia_valid & ATTR_SIZE) { 250 if (iap->ia_size < inode->i_size) { 251 err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); 252 if (err) 253 goto out; 254 } 255 256 /* 257 * If we are changing the size of the file, then 258 * we need to break all leases. 259 */ 260 err = get_lease(inode, FMODE_WRITE); 261 if (err) 262 goto out_nfserr; 263 264 err = get_write_access(inode); 265 if (err) 266 goto out_nfserr; 267 268 err = locks_verify_truncate(inode, NULL, iap->ia_size); 269 if (err) { 270 put_write_access(inode); 271 goto out_nfserr; 272 } 273 DQUOT_INIT(inode); 274 } 275 276 imode = inode->i_mode; 277 if (iap->ia_valid & ATTR_MODE) { 278 iap->ia_mode &= S_IALLUGO; 279 imode = iap->ia_mode |= (imode & ~S_IALLUGO); 280 } 281 282 /* Revoke setuid/setgid bit on chown/chgrp */ 283 if ((iap->ia_valid & ATTR_UID) && (imode & S_ISUID) 284 && iap->ia_uid != inode->i_uid) { 285 iap->ia_valid |= ATTR_MODE; 286 iap->ia_mode = imode &= ~S_ISUID; 287 } 288 if ((iap->ia_valid & ATTR_GID) && (imode & S_ISGID) 289 && iap->ia_gid != inode->i_gid) { 290 iap->ia_valid |= ATTR_MODE; 291 iap->ia_mode = imode &= ~S_ISGID; 292 } 293 294 /* Change the attributes. */ 295 296 297 iap->ia_valid |= ATTR_CTIME; 298 299 if (iap->ia_valid & ATTR_SIZE) { 300 fh_lock(fhp); 301 size_change = 1; 302 } 303 err = nfserr_notsync; 304 if (!check_guard || guardtime == inode->i_ctime) { 305 err = notify_change(dentry, iap); 306 err = nfserrno(err); 307 } 308 if (size_change) { 309 fh_unlock(fhp); 310 put_write_access(inode); 311 } 312 if (!err) 313 if (EX_ISSYNC(fhp->fh_export)) 314 write_inode_now(inode, 1); 315 out: 316 return err; 317 318 out_nfserr: 319 err = nfserrno(err); 320 goto out; 321 } 322 323 #ifdef CONFIG_NFSD_V3 324 /* 325 * Check server access rights to a file system object 326 */ 327 struct accessmap { 328 u32 access; 329 int how; 330 }; 331 static struct accessmap nfs3_regaccess[] = { 332 { NFS3_ACCESS_READ, MAY_READ }, 333 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 334 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC }, 335 { NFS3_ACCESS_EXTEND, MAY_WRITE }, 336 337 { 0, 0 } 338 }; 339 340 static struct accessmap nfs3_diraccess[] = { 341 { NFS3_ACCESS_READ, MAY_READ }, 342 { NFS3_ACCESS_LOOKUP, MAY_EXEC }, 343 { NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC }, 344 { NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE }, 345 { NFS3_ACCESS_DELETE, MAY_REMOVE }, 346 347 { 0, 0 } 348 }; 349 350 static struct accessmap nfs3_anyaccess[] = { 351 /* Some clients - Solaris 2.6 at least, make an access call 352 * to the server to check for access for things like /dev/null 353 * (which really, the server doesn't care about). So 354 * We provide simple access checking for them, looking 355 * mainly at mode bits 356 */ 357 { NFS3_ACCESS_READ, MAY_READ }, 358 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 359 { NFS3_ACCESS_MODIFY, MAY_WRITE }, 360 { NFS3_ACCESS_EXTEND, MAY_WRITE }, 361 362 { 0, 0 } 363 }; 364 365 int 366 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access) 367 { 368 struct accessmap *map; 369 struct svc_export *export; 370 struct dentry *dentry; 371 u32 query, result = 0; 372 unsigned int error; 373 374 error = fh_verify(rqstp, fhp, 0, MAY_NOP); 375 if (error) 376 goto out; 377 378 export = fhp->fh_export; 379 dentry = fhp->fh_dentry; 380 381 if (S_ISREG(dentry->d_inode->i_mode)) 382 map = nfs3_regaccess; 383 else if (S_ISDIR(dentry->d_inode->i_mode)) 384 map = nfs3_diraccess; 385 else 386 map = nfs3_anyaccess; 387 388 389 query = *access; 390 for (; map->access; map++) { 391 if (map->access & query) { 392 unsigned int err2; 393 err2 = nfsd_permission(export, dentry, map->how); 394 switch (err2) { 395 case nfs_ok: 396 result |= map->access; 397 break; 398 399 /* the following error codes just mean the access was not allowed, 400 * rather than an error occurred */ 401 case nfserr_rofs: 402 case nfserr_acces: 403 case nfserr_perm: 404 /* simply don't "or" in the access bit. */ 405 break; 406 default: 407 error = err2; 408 goto out; 409 } 410 } 411 } 412 *access = result; 413 414 out: 415 return error; 416 } 417 #endif /* CONFIG_NFSD_V3 */ 418 419 420 421 /* 422 * Open an existing file or directory. 423 * The access argument indicates the type of open (read/write/lock) 424 * N.B. After this call fhp needs an fh_put 425 */ 426 int 427 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 428 int access, struct file *filp) 429 { 430 struct dentry *dentry; 431 struct inode *inode; 432 int err; 433 434 /* If we get here, then the client has already done an "open", and (hopefully) 435 * checked permission - so allow OWNER_OVERRIDE in case a chmod has now revoked 436 * permission */ 437 err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE); 438 if (err) 439 goto out; 440 441 dentry = fhp->fh_dentry; 442 inode = dentry->d_inode; 443 444 /* Disallow access to files with the append-only bit set or 445 * with mandatory locking enabled 446 */ 447 err = nfserr_perm; 448 if (IS_APPEND(inode) || IS_ISMNDLK(inode)) 449 goto out; 450 if (!inode->i_fop) 451 goto out; 452 453 /* 454 * Check to see if there are any leases on this file. 455 * This may block while leases are broken. 456 */ 457 err = get_lease(inode, (access & MAY_WRITE) ? FMODE_WRITE : 0); 458 if (err) 459 goto out_nfserr; 460 461 if ((access & MAY_WRITE) && (err = get_write_access(inode)) != 0) 462 goto out_nfserr; 463 464 memset(filp, 0, sizeof(*filp)); 465 filp->f_op = fops_get(inode->i_fop); 466 atomic_set(&filp->f_count, 1); 467 filp->f_dentry = dentry; 468 filp->f_vfsmnt = fhp->fh_export->ex_mnt; 469 if (access & MAY_WRITE) { 470 filp->f_flags = O_WRONLY|O_LARGEFILE; 471 filp->f_mode = FMODE_WRITE; 472 DQUOT_INIT(inode); 473 } else { 474 filp->f_flags = O_RDONLY|O_LARGEFILE; 475 filp->f_mode = FMODE_READ; 476 } 477 478 err = 0; 479 if (filp->f_op && filp->f_op->open) { 480 err = filp->f_op->open(inode, filp); 481 if (err) { 482 fops_put(filp->f_op); 483 if (access & MAY_WRITE) 484 put_write_access(inode); 485 486 /* I nearly added put_filp() call here, but this filp 487 * is really on callers stack frame. -DaveM 488 */ 489 atomic_dec(&filp->f_count); 490 } 491 } 492 out_nfserr: 493 if (err) 494 err = nfserrno(err); 495 out: 496 return err; 497 } 498 499 /* 500 * Close a file. 501 */ 502 void 503 nfsd_close(struct file *filp) 504 { 505 struct dentry *dentry = filp->f_dentry; 506 struct inode *inode = dentry->d_inode; 507 508 if (filp->f_op && filp->f_op->release) 509 filp->f_op->release(inode, filp); 510 fops_put(filp->f_op); 511 if (filp->f_mode & FMODE_WRITE) 512 put_write_access(inode); 513 } 514 515 /* 516 * Sync a file 517 * As this calls fsync (not fdatasync) there is no need for a write_inode 518 * after it. 519 */ 520 inline void nfsd_dosync(struct file *filp, struct dentry *dp, 521 struct file_operations *fop) 522 { 523 struct inode *inode = dp->d_inode; 524 int (*fsync) (struct file *, struct dentry *, int); 525 526 filemap_fdatasync(inode->i_mapping); 527 if (fop && (fsync = fop->fsync)) 528 fsync(filp, dp, 0); 529 filemap_fdatawait(inode->i_mapping); 530 } 531 532 533 void 534 nfsd_sync(struct file *filp) 535 { 536 struct inode *inode = filp->f_dentry->d_inode; 537 dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); 538 down(&inode->i_sem); 539 nfsd_dosync(filp, filp->f_dentry, filp->f_op); 540 up(&inode->i_sem); 541 } 542 543 void 544 nfsd_sync_dir(struct dentry *dp) 545 { 546 nfsd_dosync(NULL, dp, dp->d_inode->i_fop); 547 } 548 549 /* 550 * Obtain the readahead parameters for the file 551 * specified by (dev, ino). 552 */ 553 static inline struct raparms * 554 nfsd_get_raparms(dev_t dev, ino_t ino) 555 { 556 struct raparms *ra, **rap, **frap = NULL; 557 int depth = 0; 558 559 for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) { 560 if (ra->p_ino == ino && ra->p_dev == dev) 561 goto found; 562 depth++; 563 if (ra->p_count == 0) 564 frap = rap; 565 } 566 depth = nfsdstats.ra_size*11/10; 567 if (!frap) 568 return NULL; 569 rap = frap; 570 ra = *frap; 571 ra->p_dev = dev; 572 ra->p_ino = ino; 573 ra->p_reada = 0; 574 ra->p_ramax = 0; 575 ra->p_raend = 0; 576 ra->p_ralen = 0; 577 ra->p_rawin = 0; 578 found: 579 if (rap != &raparm_cache) { 580 *rap = ra->p_next; 581 ra->p_next = raparm_cache; 582 raparm_cache = ra; 583 } 584 ra->p_count++; 585 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 586 return ra; 587 } 588 589 /* 590 * Read data from a file. count must contain the requested read count 591 * on entry. On return, *count contains the number of bytes actually read. 592 * N.B. After this call fhp needs an fh_put 593 */ 594 int 595 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 596 char *buf, unsigned long *count) 597 { 598 struct raparms *ra; 599 mm_segment_t oldfs; 600 int err; 601 struct file file; 602 603 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); 604 if (err) 605 goto out; 606 err = nfserr_perm; 607 if (!file.f_op->read) 608 goto out_close; 609 #ifdef MSNFS 610 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 611 (!lock_may_read(file.f_dentry->d_inode, offset, *count))) 612 goto out_close; 613 #endif 614 615 /* Get readahead parameters */ 616 ra = nfsd_get_raparms(fhp->fh_export->ex_dev, fhp->fh_dentry->d_inode->i_ino); 617 if (ra) { 618 file.f_reada = ra->p_reada; 619 file.f_ramax = ra->p_ramax; 620 file.f_raend = ra->p_raend; 621 file.f_ralen = ra->p_ralen; 622 file.f_rawin = ra->p_rawin; 623 } 624 file.f_pos = offset; 625 626 oldfs = get_fs(); set_fs(KERNEL_DS); 627 err = file.f_op->read(&file, buf, *count, &file.f_pos); 628 set_fs(oldfs); 629 630 /* Write back readahead params */ 631 if (ra != NULL) { 632 dprintk("nfsd: raparms %ld %ld %ld %ld %ld\n", 633 file.f_reada, file.f_ramax, file.f_raend, 634 file.f_ralen, file.f_rawin); 635 ra->p_reada = file.f_reada; 636 ra->p_ramax = file.f_ramax; 637 ra->p_raend = file.f_raend; 638 ra->p_ralen = file.f_ralen; 639 ra->p_rawin = file.f_rawin; 640 ra->p_count -= 1; 641 } 642 643 if (err >= 0) { 644 nfsdstats.io_read += err; 645 *count = err; 646 err = 0; 647 } else 648 err = nfserrno(err); 649 out_close: 650 nfsd_close(&file); 651 out: 652 return err; 653 } 654 655 /* 656 * Write data to a file. 657 * The stable flag requests synchronous writes. 658 * N.B. After this call fhp needs an fh_put 659 */ 660 int 661 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 662 char *buf, unsigned long cnt, int *stablep) 663 { 664 struct svc_export *exp; 665 struct file file; 666 struct dentry *dentry; 667 struct inode *inode; 668 mm_segment_t oldfs; 669 int err = 0; 670 int stable = *stablep; 671 672 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file); 673 if (err) 674 goto out; 675 if (!cnt) 676 goto out_close; 677 err = nfserr_perm; 678 if (!file.f_op->write) 679 goto out_close; 680 #ifdef MSNFS 681 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 682 (!lock_may_write(file.f_dentry->d_inode, offset, cnt))) 683 goto out_close; 684 #endif 685 686 dentry = file.f_dentry; 687 inode = dentry->d_inode; 688 exp = fhp->fh_export; 689 690 /* 691 * Request sync writes if 692 * - the sync export option has been set, or 693 * - the client requested O_SYNC behavior (NFSv3 feature). 694 * - The file system doesn't support fsync(). 695 * When gathered writes have been configured for this volume, 696 * flushing the data to disk is handled separately below. 697 */ 698 699 if (file.f_op->fsync == 0) {/* COMMIT3 cannot work */ 700 stable = 2; 701 *stablep = 2; /* FILE_SYNC */ 702 } 703 704 if (!EX_ISSYNC(exp)) 705 stable = 0; 706 if (stable && !EX_WGATHER(exp)) 707 file.f_flags |= O_SYNC; 708 709 file.f_pos = offset; /* set write offset */ 710 711 /* Write the data. */ 712 oldfs = get_fs(); set_fs(KERNEL_DS); 713 err = file.f_op->write(&file, buf, cnt, &file.f_pos); 714 if (err >= 0) 715 nfsdstats.io_write += cnt; 716 set_fs(oldfs); 717 718 /* clear setuid/setgid flag after write */ 719 if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) { 720 struct iattr ia; 721 722 ia.ia_valid = ATTR_MODE; 723 ia.ia_mode = inode->i_mode & ~(S_ISUID | S_ISGID); 724 notify_change(dentry, &ia); 725 } 726 727 if (err >= 0 && stable) { 728 static unsigned long last_ino; 729 static kdev_t last_dev = NODEV; 730 731 /* 732 * Gathered writes: If another process is currently 733 * writing to the file, there's a high chance 734 * this is another nfsd (triggered by a bulk write 735 * from a client's biod). Rather than syncing the 736 * file with each write request, we sleep for 10 msec. 737 * 738 * I don't know if this roughly approximates 739 * C. Juszak's idea of gathered writes, but it's a 740 * nice and simple solution (IMHO), and it seems to 741 * work:-) 742 */ 743 if (EX_WGATHER(exp)) { 744 if (atomic_read(&inode->i_writecount) > 1 745 || (last_ino == inode->i_ino && last_dev == inode->i_dev)) { 746 dprintk("nfsd: write defer %d\n", current->pid); 747 set_current_state(TASK_UNINTERRUPTIBLE); 748 schedule_timeout((HZ+99)/100); 749 current->state = TASK_RUNNING; 750 dprintk("nfsd: write resume %d\n", current->pid); 751 } 752 753 if (inode->i_state & I_DIRTY) { 754 dprintk("nfsd: write sync %d\n", current->pid); 755 nfsd_sync(&file); 756 } 757 #if 0 758 wake_up(&inode->i_wait); 759 #endif 760 } 761 last_ino = inode->i_ino; 762 last_dev = inode->i_dev; 763 } 764 765 dprintk("nfsd: write complete err=%d\n", err); 766 if (err >= 0) 767 err = 0; 768 else 769 err = nfserrno(err); 770 out_close: 771 nfsd_close(&file); 772 out: 773 return err; 774 } 775 776 777 #ifdef CONFIG_NFSD_V3 778 /* 779 * Commit all pending writes to stable storage. 780 * Strictly speaking, we could sync just the indicated file region here, 781 * but there's currently no way we can ask the VFS to do so. 782 * 783 * Unfortunately we cannot lock the file to make sure we return full WCC 784 * data to the client, as locking happens lower down in the filesystem. 785 */ 786 int 787 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 788 off_t offset, unsigned long count) 789 { 790 struct file file; 791 int err; 792 793 if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0) 794 return err; 795 if (EX_ISSYNC(fhp->fh_export)) { 796 if (file.f_op && file.f_op->fsync) { 797 nfsd_sync(&file); 798 } else { 799 err = nfserr_notsupp; 800 } 801 } 802 803 nfsd_close(&file); 804 return err; 805 } 806 #endif /* CONFIG_NFSD_V3 */ 807 808 /* 809 * Create a file (regular, directory, device, fifo); UNIX sockets 810 * not yet implemented. 811 * If the response fh has been verified, the parent directory should 812 * already be locked. Note that the parent directory is left locked. 813 * 814 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 815 */ 816 int 817 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 818 char *fname, int flen, struct iattr *iap, 819 int type, dev_t rdev, struct svc_fh *resfhp) 820 { 821 struct dentry *dentry, *dchild; 822 struct inode *dirp; 823 int err; 824 825 err = nfserr_perm; 826 if (!flen) 827 goto out; 828 err = nfserr_exist; 829 if (isdotent(fname, flen)) 830 goto out; 831 832 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 833 if (err) 834 goto out; 835 836 dentry = fhp->fh_dentry; 837 dirp = dentry->d_inode; 838 839 err = nfserr_notdir; 840 if(!dirp->i_op || !dirp->i_op->lookup) 841 goto out; 842 /* 843 * Check whether the response file handle has been verified yet. 844 * If it has, the parent directory should already be locked. 845 */ 846 if (!resfhp->fh_dentry) { 847 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 848 fh_lock(fhp); 849 dchild = lookup_one_len(fname, dentry, flen); 850 err = PTR_ERR(dchild); 851 if (IS_ERR(dchild)) 852 goto out_nfserr; 853 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 854 if (err) 855 goto out; 856 } else { 857 /* called from nfsd_proc_create */ 858 dchild = resfhp->fh_dentry; 859 if (!fhp->fh_locked) { 860 /* not actually possible */ 861 printk(KERN_ERR 862 "nfsd_create: parent %s/%s not locked!\n", 863 dentry->d_parent->d_name.name, 864 dentry->d_name.name); 865 err = -EIO; 866 goto out; 867 } 868 } 869 /* 870 * Make sure the child dentry is still negative ... 871 */ 872 err = nfserr_exist; 873 if (dchild->d_inode) { 874 dprintk("nfsd_create: dentry %s/%s not negative!\n", 875 dentry->d_name.name, dchild->d_name.name); 876 goto out; 877 } 878 879 if (!(iap->ia_valid & ATTR_MODE)) 880 iap->ia_mode = 0; 881 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 882 883 /* 884 * Get the dir op function pointer. 885 */ 886 err = nfserr_perm; 887 switch (type) { 888 case S_IFREG: 889 err = vfs_create(dirp, dchild, iap->ia_mode); 890 break; 891 case S_IFDIR: 892 err = vfs_mkdir(dirp, dchild, iap->ia_mode); 893 break; 894 case S_IFCHR: 895 case S_IFBLK: 896 case S_IFIFO: 897 case S_IFSOCK: 898 err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 899 break; 900 default: 901 printk("nfsd: bad file type %o in nfsd_create\n", type); 902 err = -EINVAL; 903 } 904 if (err < 0) 905 goto out_nfserr; 906 907 if (EX_ISSYNC(fhp->fh_export)) { 908 nfsd_sync_dir(dentry); 909 write_inode_now(dchild->d_inode, 1); 910 } 911 912 913 /* Set file attributes. Mode has already been set and 914 * setting uid/gid works only for root. Irix appears to 915 * send along the gid when it tries to implement setgid 916 * directories via NFS. 917 */ 918 err = 0; 919 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) 920 err = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 921 /* 922 * Update the file handle to get the new inode info. 923 */ 924 if (!err) 925 err = fh_update(resfhp); 926 out: 927 return err; 928 929 out_nfserr: 930 err = nfserrno(err); 931 goto out; 932 } 933 934 #ifdef CONFIG_NFSD_V3 935 /* 936 * NFSv3 version of nfsd_create 937 */ 938 int 939 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 940 char *fname, int flen, struct iattr *iap, 941 struct svc_fh *resfhp, int createmode, u32 *verifier) 942 { 943 struct dentry *dentry, *dchild; 944 struct inode *dirp; 945 int err; 946 __u32 v_mtime=0, v_atime=0; 947 int v_mode=0; 948 949 err = nfserr_perm; 950 if (!flen) 951 goto out; 952 err = nfserr_exist; 953 if (isdotent(fname, flen)) 954 goto out; 955 if (!(iap->ia_valid & ATTR_MODE)) 956 iap->ia_mode = 0; 957 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 958 if (err) 959 goto out; 960 961 dentry = fhp->fh_dentry; 962 dirp = dentry->d_inode; 963 964 /* Get all the sanity checks out of the way before 965 * we lock the parent. */ 966 err = nfserr_notdir; 967 if(!dirp->i_op || !dirp->i_op->lookup) 968 goto out; 969 fh_lock(fhp); 970 971 /* 972 * Compose the response file handle. 973 */ 974 dchild = lookup_one_len(fname, dentry, flen); 975 err = PTR_ERR(dchild); 976 if (IS_ERR(dchild)) 977 goto out_nfserr; 978 979 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 980 if (err) 981 goto out; 982 983 if (createmode == NFS3_CREATE_EXCLUSIVE) { 984 /* while the verifier would fit in mtime+atime, 985 * solaris7 gets confused (bugid 4218508) if these have 986 * the high bit set, so we use the mode as well 987 */ 988 v_mtime = verifier[0]&0x7fffffff; 989 v_atime = verifier[1]&0x7fffffff; 990 v_mode = S_IFREG 991 | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */ 992 | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */ 993 ; 994 } 995 996 if (dchild->d_inode) { 997 err = 0; 998 999 switch (createmode) { 1000 case NFS3_CREATE_UNCHECKED: 1001 if (! S_ISREG(dchild->d_inode->i_mode)) 1002 err = nfserr_exist; 1003 else { 1004 iap->ia_valid &= ATTR_SIZE; 1005 goto set_attr; 1006 } 1007 break; 1008 case NFS3_CREATE_EXCLUSIVE: 1009 if ( dchild->d_inode->i_mtime == v_mtime 1010 && dchild->d_inode->i_atime == v_atime 1011 && dchild->d_inode->i_mode == v_mode 1012 && dchild->d_inode->i_size == 0 ) 1013 break; 1014 /* fallthru */ 1015 case NFS3_CREATE_GUARDED: 1016 err = nfserr_exist; 1017 } 1018 goto out; 1019 } 1020 1021 err = vfs_create(dirp, dchild, iap->ia_mode); 1022 if (err < 0) 1023 goto out_nfserr; 1024 1025 if (EX_ISSYNC(fhp->fh_export)) { 1026 nfsd_sync_dir(dentry); 1027 /* setattr will sync the child (or not) */ 1028 } 1029 1030 /* 1031 * Update the filehandle to get the new inode info. 1032 */ 1033 err = fh_update(resfhp); 1034 if (err) 1035 goto out; 1036 1037 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1038 /* Cram the verifier into atime/mtime/mode */ 1039 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1040 | ATTR_MTIME_SET|ATTR_ATIME_SET 1041 | ATTR_MODE; 1042 iap->ia_mtime = v_mtime; 1043 iap->ia_atime = v_atime; 1044 iap->ia_mode = v_mode; 1045 } 1046 1047 /* Set file attributes. 1048 * Mode has already been set but we might need to reset it 1049 * for CREATE_EXCLUSIVE 1050 * Irix appears to send along the gid when it tries to 1051 * implement setgid directories via NFS. Clear out all that cruft. 1052 */ 1053 set_attr: 1054 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0) 1055 err = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1056 1057 out: 1058 fh_unlock(fhp); 1059 return err; 1060 1061 out_nfserr: 1062 err = nfserrno(err); 1063 goto out; 1064 } 1065 #endif /* CONFIG_NFSD_V3 */ 1066 1067 /* 1068 * Read a symlink. On entry, *lenp must contain the maximum path length that 1069 * fits into the buffer. On return, it contains the true length. 1070 * N.B. After this call fhp needs an fh_put 1071 */ 1072 int 1073 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1074 { 1075 struct dentry *dentry; 1076 struct inode *inode; 1077 mm_segment_t oldfs; 1078 int err; 1079 1080 err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP); 1081 if (err) 1082 goto out; 1083 1084 dentry = fhp->fh_dentry; 1085 inode = dentry->d_inode; 1086 1087 err = nfserr_inval; 1088 if (!inode->i_op || !inode->i_op->readlink) 1089 goto out; 1090 1091 UPDATE_ATIME(inode); 1092 /* N.B. Why does this call need a get_fs()?? 1093 * Remove the set_fs and watch the fireworks:-) --okir 1094 */ 1095 1096 oldfs = get_fs(); set_fs(KERNEL_DS); 1097 err = inode->i_op->readlink(dentry, buf, *lenp); 1098 set_fs(oldfs); 1099 1100 if (err < 0) 1101 goto out_nfserr; 1102 *lenp = err; 1103 err = 0; 1104 out: 1105 return err; 1106 1107 out_nfserr: 1108 err = nfserrno(err); 1109 goto out; 1110 } 1111 1112 /* 1113 * Create a symlink and look up its inode 1114 * N.B. After this call _both_ fhp and resfhp need an fh_put 1115 */ 1116 int 1117 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1118 char *fname, int flen, 1119 char *path, int plen, 1120 struct svc_fh *resfhp, 1121 struct iattr *iap) 1122 { 1123 struct dentry *dentry, *dnew; 1124 int err, cerr; 1125 1126 err = nfserr_noent; 1127 if (!flen || !plen) 1128 goto out; 1129 err = nfserr_exist; 1130 if (isdotent(fname, flen)) 1131 goto out; 1132 1133 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1134 if (err) 1135 goto out; 1136 fh_lock(fhp); 1137 dentry = fhp->fh_dentry; 1138 dnew = lookup_one_len(fname, dentry, flen); 1139 err = PTR_ERR(dnew); 1140 if (IS_ERR(dnew)) 1141 goto out_nfserr; 1142 1143 err = vfs_symlink(dentry->d_inode, dnew, path); 1144 if (!err) { 1145 if (EX_ISSYNC(fhp->fh_export)) 1146 nfsd_sync_dir(dentry); 1147 if (iap) { 1148 iap->ia_valid &= ATTR_MODE /* ~(ATTR_MODE|ATTR_UID|ATTR_GID)*/; 1149 if (iap->ia_valid) { 1150 iap->ia_valid |= ATTR_CTIME; 1151 iap->ia_mode = (iap->ia_mode&S_IALLUGO) 1152 | S_IFLNK; 1153 err = notify_change(dnew, iap); 1154 if (err) 1155 err = nfserrno(err); 1156 else if (EX_ISSYNC(fhp->fh_export)) 1157 write_inode_now(dentry->d_inode, 1); 1158 } 1159 } 1160 } else 1161 err = nfserrno(err); 1162 fh_unlock(fhp); 1163 1164 /* Compose the fh so the dentry will be freed ... */ 1165 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1166 if (err==0) err = cerr; 1167 out: 1168 return err; 1169 1170 out_nfserr: 1171 err = nfserrno(err); 1172 goto out; 1173 } 1174 1175 /* 1176 * Create a hardlink 1177 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1178 */ 1179 int 1180 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1181 char *name, int len, struct svc_fh *tfhp) 1182 { 1183 struct dentry *ddir, *dnew, *dold; 1184 struct inode *dirp, *dest; 1185 int err; 1186 1187 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE); 1188 if (err) 1189 goto out; 1190 err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP); 1191 if (err) 1192 goto out; 1193 1194 err = nfserr_perm; 1195 if (!len) 1196 goto out; 1197 err = nfserr_exist; 1198 if (isdotent(name, len)) 1199 goto out; 1200 1201 fh_lock(ffhp); 1202 ddir = ffhp->fh_dentry; 1203 dirp = ddir->d_inode; 1204 1205 dnew = lookup_one_len(name, ddir, len); 1206 err = PTR_ERR(dnew); 1207 if (IS_ERR(dnew)) 1208 goto out_nfserr; 1209 1210 dold = tfhp->fh_dentry; 1211 dest = dold->d_inode; 1212 1213 err = vfs_link(dold, dirp, dnew); 1214 if (!err) { 1215 if (EX_ISSYNC(ffhp->fh_export)) { 1216 nfsd_sync_dir(ddir); 1217 write_inode_now(dest, 1); 1218 } 1219 } else { 1220 if (err == -EXDEV && rqstp->rq_vers == 2) 1221 err = nfserr_acces; 1222 else 1223 err = nfserrno(err); 1224 } 1225 1226 fh_unlock(ffhp); 1227 dput(dnew); 1228 out: 1229 return err; 1230 1231 out_nfserr: 1232 err = nfserrno(err); 1233 goto out; 1234 } 1235 1236 /* 1237 * Rename a file 1238 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1239 */ 1240 int 1241 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1242 struct svc_fh *tfhp, char *tname, int tlen) 1243 { 1244 struct dentry *fdentry, *tdentry, *odentry, *ndentry; 1245 struct inode *fdir, *tdir; 1246 int err; 1247 1248 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE); 1249 if (err) 1250 goto out; 1251 err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE); 1252 if (err) 1253 goto out; 1254 1255 fdentry = ffhp->fh_dentry; 1256 fdir = fdentry->d_inode; 1257 1258 tdentry = tfhp->fh_dentry; 1259 tdir = tdentry->d_inode; 1260 1261 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1262 if (fdir->i_dev != tdir->i_dev) 1263 goto out; 1264 1265 err = nfserr_perm; 1266 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1267 goto out; 1268 1269 /* cannot use fh_lock as we need deadlock protective ordering 1270 * so do it by hand */ 1271 double_down(&tdir->i_sem, &fdir->i_sem); 1272 ffhp->fh_locked = tfhp->fh_locked = 1; 1273 fill_pre_wcc(ffhp); 1274 fill_pre_wcc(tfhp); 1275 1276 odentry = lookup_one_len(fname, fdentry, flen); 1277 err = PTR_ERR(odentry); 1278 if (IS_ERR(odentry)) 1279 goto out_nfserr; 1280 1281 err = -ENOENT; 1282 if (!odentry->d_inode) 1283 goto out_dput_old; 1284 1285 ndentry = lookup_one_len(tname, tdentry, tlen); 1286 err = PTR_ERR(ndentry); 1287 if (IS_ERR(ndentry)) 1288 goto out_dput_old; 1289 1290 1291 #ifdef MSNFS 1292 if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1293 ((atomic_read(&odentry->d_count) > 1) 1294 || (atomic_read(&ndentry->d_count) > 1))) { 1295 err = nfserr_perm; 1296 } else 1297 #endif 1298 err = vfs_rename(fdir, odentry, tdir, ndentry); 1299 if (!err && EX_ISSYNC(tfhp->fh_export)) { 1300 nfsd_sync_dir(tdentry); 1301 nfsd_sync_dir(fdentry); 1302 } 1303 dput(ndentry); 1304 1305 out_dput_old: 1306 dput(odentry); 1307 out_nfserr: 1308 if (err) 1309 err = nfserrno(err); 1310 1311 /* we cannot reply on fh_unlock on the two filehandles, 1312 * as that would do the wrong thing if the two directories 1313 * were the same, so again we do it by hand 1314 */ 1315 fill_post_wcc(ffhp); 1316 fill_post_wcc(tfhp); 1317 double_up(&tdir->i_sem, &fdir->i_sem); 1318 ffhp->fh_locked = tfhp->fh_locked = 0; 1319 1320 out: 1321 return err; 1322 } 1323 1324 /* 1325 * Unlink a file or directory 1326 * N.B. After this call fhp needs an fh_put 1327 */ 1328 int 1329 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1330 char *fname, int flen) 1331 { 1332 struct dentry *dentry, *rdentry; 1333 struct inode *dirp; 1334 int err; 1335 1336 err = nfserr_acces; 1337 if (!flen || isdotent(fname, flen)) 1338 goto out; 1339 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE); 1340 if (err) 1341 goto out; 1342 1343 fh_lock(fhp); 1344 dentry = fhp->fh_dentry; 1345 dirp = dentry->d_inode; 1346 1347 rdentry = lookup_one_len(fname, dentry, flen); 1348 err = PTR_ERR(rdentry); 1349 if (IS_ERR(rdentry)) 1350 goto out_nfserr; 1351 1352 if (!rdentry->d_inode) { 1353 dput(rdentry); 1354 err = nfserr_noent; 1355 goto out; 1356 } 1357 1358 if (type != S_IFDIR) { /* It's UNLINK */ 1359 #ifdef MSNFS 1360 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1361 (atomic_read(&rdentry->d_count) > 1)) { 1362 err = nfserr_perm; 1363 } else 1364 #endif 1365 err = vfs_unlink(dirp, rdentry); 1366 } else { /* It's RMDIR */ 1367 err = vfs_rmdir(dirp, rdentry); 1368 } 1369 1370 dput(rdentry); 1371 1372 if (err) 1373 goto out_nfserr; 1374 if (EX_ISSYNC(fhp->fh_export)) 1375 nfsd_sync_dir(dentry); 1376 1377 out: 1378 return err; 1379 1380 out_nfserr: 1381 err = nfserrno(err); 1382 goto out; 1383 } 1384 1385 /* 1386 * Read entries from a directory. 1387 * The verifier is an NFSv3 thing we ignore for now. 1388 */ 1389 int 1390 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 1391 encode_dent_fn func, u32 *buffer, int *countp, u32 *verf) 1392 { 1393 u32 *p; 1394 int oldlen, eof, err; 1395 struct file file; 1396 struct readdir_cd cd; 1397 1398 err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); 1399 if (err) 1400 goto out; 1401 if (offset > ~(u32) 0) 1402 goto out_close; 1403 1404 file.f_pos = offset; 1405 1406 /* Set up the readdir context */ 1407 memset(&cd, 0, sizeof(cd)); 1408 cd.rqstp = rqstp; 1409 cd.buffer = buffer; 1410 cd.buflen = *countp; /* count of words */ 1411 cd.dirfh = fhp; 1412 1413 /* 1414 * Read the directory entries. This silly loop is necessary because 1415 * readdir() is not guaranteed to fill up the entire buffer, but 1416 * may choose to do less. 1417 */ 1418 1419 do { 1420 oldlen = cd.buflen; 1421 1422 err = vfs_readdir(&file, (filldir_t) func, &cd); 1423 1424 if (err < 0) 1425 goto out_nfserr; 1426 1427 } while (oldlen != cd.buflen && !cd.eob); 1428 1429 /* If we didn't fill the buffer completely, we're at EOF */ 1430 eof = !cd.eob; 1431 1432 if (cd.offset) { 1433 if (rqstp->rq_vers == 3) 1434 (void)xdr_encode_hyper(cd.offset, file.f_pos); 1435 else 1436 *cd.offset = htonl(file.f_pos); 1437 } 1438 1439 p = cd.buffer; 1440 *p++ = 0; /* no more entries */ 1441 *p++ = htonl(eof); /* end of directory */ 1442 *countp = (caddr_t) p - (caddr_t) buffer; 1443 1444 dprintk("nfsd: readdir result %d bytes, eof %d offset %d\n", 1445 *countp, eof, 1446 cd.offset? ntohl(*cd.offset) : -1); 1447 err = 0; 1448 out_close: 1449 nfsd_close(&file); 1450 out: 1451 return err; 1452 1453 out_nfserr: 1454 err = nfserrno(err); 1455 goto out_close; 1456 } 1457 1458 /* 1459 * Get file system stats 1460 * N.B. After this call fhp needs an fh_put 1461 */ 1462 int 1463 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct statfs *stat) 1464 { 1465 int err = fh_verify(rqstp, fhp, 0, MAY_NOP); 1466 if (!err && vfs_statfs(fhp->fh_dentry->d_inode->i_sb,stat)) 1467 err = nfserr_io; 1468 return err; 1469 } 1470 1471 /* 1472 * Check for a user's access permissions to this inode. 1473 */ 1474 int 1475 nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc) 1476 { 1477 struct inode *inode = dentry->d_inode; 1478 int err; 1479 1480 if (acc == MAY_NOP) 1481 return 0; 1482 #if 0 1483 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 1484 acc, 1485 (acc & MAY_READ)? " read" : "", 1486 (acc & MAY_WRITE)? " write" : "", 1487 (acc & MAY_EXEC)? " exec" : "", 1488 (acc & MAY_SATTR)? " sattr" : "", 1489 (acc & MAY_TRUNC)? " trunc" : "", 1490 (acc & MAY_LOCK)? " lock" : "", 1491 (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "", 1492 inode->i_mode, 1493 IS_IMMUTABLE(inode)? " immut" : "", 1494 IS_APPEND(inode)? " append" : "", 1495 IS_RDONLY(inode)? " ro" : ""); 1496 dprintk(" owner %d/%d user %d/%d\n", 1497 inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); 1498 #endif 1499 1500 /* The following code is here to make IRIX happy, which 1501 * does a permission check every time a user does 1502 * echo yaddayadda > special-file 1503 * by sending a CREATE request. 1504 * The original code would check read-only export status 1505 * only for regular files and directories, allowing 1506 * clients to chown/chmod device files and fifos even 1507 * on volumes exported read-only. */ 1508 if (!(acc & _NFSD_IRIX_BOGOSITY) 1509 && (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC))) { 1510 if (EX_RDONLY(exp) || IS_RDONLY(inode)) 1511 return nfserr_rofs; 1512 if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) 1513 return nfserr_perm; 1514 } 1515 if ((acc & MAY_TRUNC) && IS_APPEND(inode)) 1516 return nfserr_perm; 1517 1518 if (acc & MAY_LOCK) { 1519 /* If we cannot rely on authentication in NLM requests, 1520 * just allow locks, otherwise require read permission, or 1521 * ownership 1522 */ 1523 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 1524 return 0; 1525 else 1526 acc = MAY_READ | MAY_OWNER_OVERRIDE; 1527 } 1528 /* 1529 * The file owner always gets access permission for accesses that 1530 * would normally be checked at open time. This is to make 1531 * file access work even when the client has done a fchmod(fd, 0). 1532 * 1533 * However, `cp foo bar' should fail nevertheless when bar is 1534 * readonly. A sensible way to do this might be to reject all 1535 * attempts to truncate a read-only file, because a creat() call 1536 * always implies file truncation. 1537 * ... but this isn't really fair. A process may reasonably call 1538 * ftruncate on an open file descriptor on a file with perm 000. 1539 * We must trust the client to do permission checking - using "ACCESS" 1540 * with NFSv3. 1541 */ 1542 if ((acc & MAY_OWNER_OVERRIDE) && 1543 inode->i_uid == current->fsuid) 1544 return 0; 1545 1546 err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 1547 1548 /* Allow read access to binaries even when mode 111 */ 1549 if (err == -EACCES && S_ISREG(inode->i_mode) && 1550 acc == (MAY_READ | MAY_OWNER_OVERRIDE)) 1551 err = permission(inode, MAY_EXEC); 1552 1553 return err? nfserrno(err) : 0; 1554 } 1555 1556 void 1557 nfsd_racache_shutdown(void) 1558 { 1559 if (!raparm_cache) 1560 return; 1561 dprintk("nfsd: freeing readahead buffers.\n"); 1562 kfree(raparml); 1563 raparm_cache = raparml = NULL; 1564 } 1565 /* 1566 * Initialize readahead param cache 1567 */ 1568 int 1569 nfsd_racache_init(int cache_size) 1570 { 1571 int i; 1572 1573 if (raparm_cache) 1574 return 0; 1575 raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); 1576 1577 if (raparml != NULL) { 1578 dprintk("nfsd: allocating %d readahead buffers.\n", 1579 cache_size); 1580 memset(raparml, 0, sizeof(struct raparms) * cache_size); 1581 for (i = 0; i < cache_size - 1; i++) { 1582 raparml[i].p_next = raparml + i + 1; 1583 } 1584 raparm_cache = raparml; 1585 } else { 1586 printk(KERN_WARNING 1587 "nfsd: Could not allocate memory read-ahead cache.\n"); 1588 return -ENOMEM; 1589 } 1590 nfsdstats.ra_size = cache_size; 1591 return 0; 1592 }
Cache object: 25934574cac5c76f79d075bc8a9af860
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