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 exported, 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 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 17 */ 18 19 #include <linux/config.h> 20 #include <linux/string.h> 21 #include <linux/time.h> 22 #include <linux/errno.h> 23 #include <linux/fs.h> 24 #include <linux/file.h> 25 #include <linux/mount.h> 26 #include <linux/major.h> 27 #include <linux/ext2_fs.h> 28 #include <linux/proc_fs.h> 29 #include <linux/stat.h> 30 #include <linux/fcntl.h> 31 #include <linux/net.h> 32 #include <linux/unistd.h> 33 #include <linux/slab.h> 34 #include <linux/pagemap.h> 35 #include <linux/in.h> 36 #include <linux/module.h> 37 #include <linux/namei.h> 38 #include <linux/vfs.h> 39 #include <linux/delay.h> 40 #include <linux/sunrpc/svc.h> 41 #include <linux/nfsd/nfsd.h> 42 #ifdef CONFIG_NFSD_V3 43 #include <linux/nfs3.h> 44 #include <linux/nfsd/xdr3.h> 45 #endif /* CONFIG_NFSD_V3 */ 46 #include <linux/nfsd/nfsfh.h> 47 #include <linux/quotaops.h> 48 #include <linux/fsnotify.h> 49 #include <linux/posix_acl.h> 50 #include <linux/posix_acl_xattr.h> 51 #include <linux/xattr.h> 52 #ifdef CONFIG_NFSD_V4 53 #include <linux/nfs4.h> 54 #include <linux/nfs4_acl.h> 55 #include <linux/nfsd_idmap.h> 56 #include <linux/security.h> 57 #endif /* CONFIG_NFSD_V4 */ 58 59 #include <asm/uaccess.h> 60 61 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 62 #define NFSD_PARANOIA 63 64 65 /* We must ignore files (but only files) which might have mandatory 66 * locks on them because there is no way to know if the accesser has 67 * the lock. 68 */ 69 #define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i)) 70 71 /* 72 * This is a cache of readahead params that help us choose the proper 73 * readahead strategy. Initially, we set all readahead parameters to 0 74 * and let the VFS handle things. 75 * If you increase the number of cached files very much, you'll need to 76 * add a hash table here. 77 */ 78 struct raparms { 79 struct raparms *p_next; 80 unsigned int p_count; 81 ino_t p_ino; 82 dev_t p_dev; 83 int p_set; 84 struct file_ra_state p_ra; 85 }; 86 87 static struct raparms * raparml; 88 static struct raparms * raparm_cache; 89 90 /* 91 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 92 * a mount point. 93 * Returns -EAGAIN leaving *dpp and *expp unchanged, 94 * or nfs_ok having possibly changed *dpp and *expp 95 */ 96 int 97 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 98 struct svc_export **expp) 99 { 100 struct svc_export *exp = *expp, *exp2 = NULL; 101 struct dentry *dentry = *dpp; 102 struct vfsmount *mnt = mntget(exp->ex_mnt); 103 struct dentry *mounts = dget(dentry); 104 int err = nfs_ok; 105 106 while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)); 107 108 exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle); 109 if (IS_ERR(exp2)) { 110 err = PTR_ERR(exp2); 111 dput(mounts); 112 mntput(mnt); 113 goto out; 114 } 115 if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2))) { 116 /* successfully crossed mount point */ 117 exp_put(exp); 118 *expp = exp2; 119 dput(dentry); 120 *dpp = mounts; 121 } else { 122 if (exp2) exp_put(exp2); 123 dput(mounts); 124 } 125 mntput(mnt); 126 out: 127 return err; 128 } 129 130 /* 131 * Look up one component of a pathname. 132 * N.B. After this call _both_ fhp and resfh need an fh_put 133 * 134 * If the lookup would cross a mountpoint, and the mounted filesystem 135 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 136 * accepted as it stands and the mounted directory is 137 * returned. Otherwise the covered directory is returned. 138 * NOTE: this mountpoint crossing is not supported properly by all 139 * clients and is explicitly disallowed for NFSv3 140 * NeilBrown <neilb@cse.unsw.edu.au> 141 */ 142 int 143 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 144 int len, struct svc_fh *resfh) 145 { 146 struct svc_export *exp; 147 struct dentry *dparent; 148 struct dentry *dentry; 149 int err; 150 151 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 152 153 /* Obtain dentry and export. */ 154 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC); 155 if (err) 156 return err; 157 158 dparent = fhp->fh_dentry; 159 exp = fhp->fh_export; 160 exp_get(exp); 161 162 err = nfserr_acces; 163 164 /* Lookup the name, but don't follow links */ 165 if (isdotent(name, len)) { 166 if (len==1) 167 dentry = dget(dparent); 168 else if (dparent != exp->ex_dentry) { 169 dentry = dget_parent(dparent); 170 } else if (!EX_NOHIDE(exp)) 171 dentry = dget(dparent); /* .. == . just like at / */ 172 else { 173 /* checking mountpoint crossing is very different when stepping up */ 174 struct svc_export *exp2 = NULL; 175 struct dentry *dp; 176 struct vfsmount *mnt = mntget(exp->ex_mnt); 177 dentry = dget(dparent); 178 while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry)) 179 ; 180 dp = dget_parent(dentry); 181 dput(dentry); 182 dentry = dp; 183 184 exp2 = exp_parent(exp->ex_client, mnt, dentry, 185 &rqstp->rq_chandle); 186 if (IS_ERR(exp2)) { 187 err = PTR_ERR(exp2); 188 dput(dentry); 189 mntput(mnt); 190 goto out_nfserr; 191 } 192 if (!exp2) { 193 dput(dentry); 194 dentry = dget(dparent); 195 } else { 196 exp_put(exp); 197 exp = exp2; 198 } 199 mntput(mnt); 200 } 201 } else { 202 fh_lock(fhp); 203 dentry = lookup_one_len(name, dparent, len); 204 err = PTR_ERR(dentry); 205 if (IS_ERR(dentry)) 206 goto out_nfserr; 207 /* 208 * check if we have crossed a mount point ... 209 */ 210 if (d_mountpoint(dentry)) { 211 if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 212 dput(dentry); 213 goto out_nfserr; 214 } 215 } 216 } 217 /* 218 * Note: we compose the file handle now, but as the 219 * dentry may be negative, it may need to be updated. 220 */ 221 err = fh_compose(resfh, exp, dentry, fhp); 222 if (!err && !dentry->d_inode) 223 err = nfserr_noent; 224 dput(dentry); 225 out: 226 exp_put(exp); 227 return err; 228 229 out_nfserr: 230 err = nfserrno(err); 231 goto out; 232 } 233 234 /* 235 * Set various file attributes. 236 * N.B. After this call fhp needs an fh_put 237 */ 238 int 239 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 240 int check_guard, time_t guardtime) 241 { 242 struct dentry *dentry; 243 struct inode *inode; 244 int accmode = MAY_SATTR; 245 int ftype = 0; 246 int imode; 247 int err; 248 int size_change = 0; 249 250 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 251 accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE; 252 if (iap->ia_valid & ATTR_SIZE) 253 ftype = S_IFREG; 254 255 /* Get inode */ 256 err = fh_verify(rqstp, fhp, ftype, accmode); 257 if (err) 258 goto out; 259 260 dentry = fhp->fh_dentry; 261 inode = dentry->d_inode; 262 263 /* Ignore any mode updates on symlinks */ 264 if (S_ISLNK(inode->i_mode)) 265 iap->ia_valid &= ~ATTR_MODE; 266 267 if (!iap->ia_valid) 268 goto out; 269 270 /* NFSv2 does not differentiate between "set-[ac]time-to-now" 271 * which only requires access, and "set-[ac]time-to-X" which 272 * requires ownership. 273 * So if it looks like it might be "set both to the same time which 274 * is close to now", and if inode_change_ok fails, then we 275 * convert to "set to now" instead of "set to explicit time" 276 * 277 * We only call inode_change_ok as the last test as technically 278 * it is not an interface that we should be using. It is only 279 * valid if the filesystem does not define it's own i_op->setattr. 280 */ 281 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 282 #define MAX_TOUCH_TIME_ERROR (30*60) 283 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET 284 && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec 285 ) { 286 /* Looks probable. Now just make sure time is in the right ballpark. 287 * Solaris, at least, doesn't seem to care what the time request is. 288 * We require it be within 30 minutes of now. 289 */ 290 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 291 if (delta<0) delta = -delta; 292 if (delta < MAX_TOUCH_TIME_ERROR && 293 inode_change_ok(inode, iap) != 0) { 294 /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME 295 * this will cause notify_change to set these times to "now" 296 */ 297 iap->ia_valid &= ~BOTH_TIME_SET; 298 } 299 } 300 301 /* The size case is special. It changes the file as well as the attributes. */ 302 if (iap->ia_valid & ATTR_SIZE) { 303 if (iap->ia_size < inode->i_size) { 304 err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); 305 if (err) 306 goto out; 307 } 308 309 /* 310 * If we are changing the size of the file, then 311 * we need to break all leases. 312 */ 313 err = break_lease(inode, FMODE_WRITE | O_NONBLOCK); 314 if (err == -EWOULDBLOCK) 315 err = -ETIMEDOUT; 316 if (err) /* ENOMEM or EWOULDBLOCK */ 317 goto out_nfserr; 318 319 err = get_write_access(inode); 320 if (err) 321 goto out_nfserr; 322 323 size_change = 1; 324 err = locks_verify_truncate(inode, NULL, iap->ia_size); 325 if (err) { 326 put_write_access(inode); 327 goto out_nfserr; 328 } 329 DQUOT_INIT(inode); 330 } 331 332 imode = inode->i_mode; 333 if (iap->ia_valid & ATTR_MODE) { 334 iap->ia_mode &= S_IALLUGO; 335 imode = iap->ia_mode |= (imode & ~S_IALLUGO); 336 } 337 338 /* Revoke setuid/setgid bit on chown/chgrp */ 339 if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) 340 iap->ia_valid |= ATTR_KILL_SUID; 341 if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid) 342 iap->ia_valid |= ATTR_KILL_SGID; 343 344 /* Change the attributes. */ 345 346 iap->ia_valid |= ATTR_CTIME; 347 348 err = nfserr_notsync; 349 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 350 fh_lock(fhp); 351 err = notify_change(dentry, iap); 352 err = nfserrno(err); 353 fh_unlock(fhp); 354 } 355 if (size_change) 356 put_write_access(inode); 357 if (!err) 358 if (EX_ISSYNC(fhp->fh_export)) 359 write_inode_now(inode, 1); 360 out: 361 return err; 362 363 out_nfserr: 364 err = nfserrno(err); 365 goto out; 366 } 367 368 #if defined(CONFIG_NFSD_V2_ACL) || \ 369 defined(CONFIG_NFSD_V3_ACL) || \ 370 defined(CONFIG_NFSD_V4) 371 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 372 { 373 ssize_t buflen; 374 375 buflen = vfs_getxattr(dentry, key, NULL, 0); 376 if (buflen <= 0) 377 return buflen; 378 379 *buf = kmalloc(buflen, GFP_KERNEL); 380 if (!*buf) 381 return -ENOMEM; 382 383 return vfs_getxattr(dentry, key, *buf, buflen); 384 } 385 #endif 386 387 #if defined(CONFIG_NFSD_V4) 388 static int 389 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 390 { 391 int len; 392 size_t buflen; 393 char *buf = NULL; 394 int error = 0; 395 396 buflen = posix_acl_xattr_size(pacl->a_count); 397 buf = kmalloc(buflen, GFP_KERNEL); 398 error = -ENOMEM; 399 if (buf == NULL) 400 goto out; 401 402 len = posix_acl_to_xattr(pacl, buf, buflen); 403 if (len < 0) { 404 error = len; 405 goto out; 406 } 407 408 error = vfs_setxattr(dentry, key, buf, len, 0); 409 out: 410 kfree(buf); 411 return error; 412 } 413 414 int 415 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 416 struct nfs4_acl *acl) 417 { 418 int error; 419 struct dentry *dentry; 420 struct inode *inode; 421 struct posix_acl *pacl = NULL, *dpacl = NULL; 422 unsigned int flags = 0; 423 424 /* Get inode */ 425 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR); 426 if (error) 427 goto out; 428 429 dentry = fhp->fh_dentry; 430 inode = dentry->d_inode; 431 if (S_ISDIR(inode->i_mode)) 432 flags = NFS4_ACL_DIR; 433 434 error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 435 if (error == -EINVAL) { 436 error = nfserr_attrnotsupp; 437 goto out; 438 } else if (error < 0) 439 goto out_nfserr; 440 441 if (pacl) { 442 error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 443 if (error < 0) 444 goto out_nfserr; 445 } 446 447 if (dpacl) { 448 error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 449 if (error < 0) 450 goto out_nfserr; 451 } 452 453 error = nfs_ok; 454 455 out: 456 posix_acl_release(pacl); 457 posix_acl_release(dpacl); 458 return (error); 459 out_nfserr: 460 error = nfserrno(error); 461 goto out; 462 } 463 464 static struct posix_acl * 465 _get_posix_acl(struct dentry *dentry, char *key) 466 { 467 void *buf = NULL; 468 struct posix_acl *pacl = NULL; 469 int buflen; 470 471 buflen = nfsd_getxattr(dentry, key, &buf); 472 if (!buflen) 473 buflen = -ENODATA; 474 if (buflen <= 0) 475 return ERR_PTR(buflen); 476 477 pacl = posix_acl_from_xattr(buf, buflen); 478 kfree(buf); 479 return pacl; 480 } 481 482 int 483 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 484 { 485 struct inode *inode = dentry->d_inode; 486 int error = 0; 487 struct posix_acl *pacl = NULL, *dpacl = NULL; 488 unsigned int flags = 0; 489 490 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 491 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 492 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 493 if (IS_ERR(pacl)) { 494 error = PTR_ERR(pacl); 495 pacl = NULL; 496 goto out; 497 } 498 499 if (S_ISDIR(inode->i_mode)) { 500 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 501 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 502 dpacl = NULL; 503 else if (IS_ERR(dpacl)) { 504 error = PTR_ERR(dpacl); 505 dpacl = NULL; 506 goto out; 507 } 508 flags = NFS4_ACL_DIR; 509 } 510 511 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 512 if (IS_ERR(*acl)) { 513 error = PTR_ERR(*acl); 514 *acl = NULL; 515 } 516 out: 517 posix_acl_release(pacl); 518 posix_acl_release(dpacl); 519 return error; 520 } 521 522 #endif /* defined(CONFIG_NFS_V4) */ 523 524 #ifdef CONFIG_NFSD_V3 525 /* 526 * Check server access rights to a file system object 527 */ 528 struct accessmap { 529 u32 access; 530 int how; 531 }; 532 static struct accessmap nfs3_regaccess[] = { 533 { NFS3_ACCESS_READ, MAY_READ }, 534 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 535 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC }, 536 { NFS3_ACCESS_EXTEND, MAY_WRITE }, 537 538 { 0, 0 } 539 }; 540 541 static struct accessmap nfs3_diraccess[] = { 542 { NFS3_ACCESS_READ, MAY_READ }, 543 { NFS3_ACCESS_LOOKUP, MAY_EXEC }, 544 { NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC }, 545 { NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE }, 546 { NFS3_ACCESS_DELETE, MAY_REMOVE }, 547 548 { 0, 0 } 549 }; 550 551 static struct accessmap nfs3_anyaccess[] = { 552 /* Some clients - Solaris 2.6 at least, make an access call 553 * to the server to check for access for things like /dev/null 554 * (which really, the server doesn't care about). So 555 * We provide simple access checking for them, looking 556 * mainly at mode bits, and we make sure to ignore read-only 557 * filesystem checks 558 */ 559 { NFS3_ACCESS_READ, MAY_READ }, 560 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 561 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_LOCAL_ACCESS }, 562 { NFS3_ACCESS_EXTEND, MAY_WRITE|MAY_LOCAL_ACCESS }, 563 564 { 0, 0 } 565 }; 566 567 int 568 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 569 { 570 struct accessmap *map; 571 struct svc_export *export; 572 struct dentry *dentry; 573 u32 query, result = 0, sresult = 0; 574 unsigned int error; 575 576 error = fh_verify(rqstp, fhp, 0, MAY_NOP); 577 if (error) 578 goto out; 579 580 export = fhp->fh_export; 581 dentry = fhp->fh_dentry; 582 583 if (S_ISREG(dentry->d_inode->i_mode)) 584 map = nfs3_regaccess; 585 else if (S_ISDIR(dentry->d_inode->i_mode)) 586 map = nfs3_diraccess; 587 else 588 map = nfs3_anyaccess; 589 590 591 query = *access; 592 for (; map->access; map++) { 593 if (map->access & query) { 594 unsigned int err2; 595 596 sresult |= map->access; 597 598 err2 = nfsd_permission(export, dentry, map->how); 599 switch (err2) { 600 case nfs_ok: 601 result |= map->access; 602 break; 603 604 /* the following error codes just mean the access was not allowed, 605 * rather than an error occurred */ 606 case nfserr_rofs: 607 case nfserr_acces: 608 case nfserr_perm: 609 /* simply don't "or" in the access bit. */ 610 break; 611 default: 612 error = err2; 613 goto out; 614 } 615 } 616 } 617 *access = result; 618 if (supported) 619 *supported = sresult; 620 621 out: 622 return error; 623 } 624 #endif /* CONFIG_NFSD_V3 */ 625 626 627 628 /* 629 * Open an existing file or directory. 630 * The access argument indicates the type of open (read/write/lock) 631 * N.B. After this call fhp needs an fh_put 632 */ 633 int 634 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 635 int access, struct file **filp) 636 { 637 struct dentry *dentry; 638 struct inode *inode; 639 int flags = O_RDONLY|O_LARGEFILE, err; 640 641 /* 642 * If we get here, then the client has already done an "open", 643 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 644 * in case a chmod has now revoked permission. 645 */ 646 err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE); 647 if (err) 648 goto out; 649 650 dentry = fhp->fh_dentry; 651 inode = dentry->d_inode; 652 653 /* Disallow write access to files with the append-only bit set 654 * or any access when mandatory locking enabled 655 */ 656 err = nfserr_perm; 657 if (IS_APPEND(inode) && (access & MAY_WRITE)) 658 goto out; 659 if (IS_ISMNDLK(inode)) 660 goto out; 661 662 if (!inode->i_fop) 663 goto out; 664 665 /* 666 * Check to see if there are any leases on this file. 667 * This may block while leases are broken. 668 */ 669 err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0)); 670 if (err == -EWOULDBLOCK) 671 err = -ETIMEDOUT; 672 if (err) /* NOMEM or WOULDBLOCK */ 673 goto out_nfserr; 674 675 if (access & MAY_WRITE) { 676 flags = O_WRONLY|O_LARGEFILE; 677 678 DQUOT_INIT(inode); 679 } 680 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags); 681 if (IS_ERR(*filp)) 682 err = PTR_ERR(*filp); 683 out_nfserr: 684 if (err) 685 err = nfserrno(err); 686 out: 687 return err; 688 } 689 690 /* 691 * Close a file. 692 */ 693 void 694 nfsd_close(struct file *filp) 695 { 696 fput(filp); 697 } 698 699 /* 700 * Sync a file 701 * As this calls fsync (not fdatasync) there is no need for a write_inode 702 * after it. 703 */ 704 static inline int nfsd_dosync(struct file *filp, struct dentry *dp, 705 const struct file_operations *fop) 706 { 707 struct inode *inode = dp->d_inode; 708 int (*fsync) (struct file *, struct dentry *, int); 709 int err; 710 711 err = filemap_fdatawrite(inode->i_mapping); 712 if (err == 0 && fop && (fsync = fop->fsync)) 713 err = fsync(filp, dp, 0); 714 if (err == 0) 715 err = filemap_fdatawait(inode->i_mapping); 716 717 return err; 718 } 719 720 721 static int 722 nfsd_sync(struct file *filp) 723 { 724 int err; 725 struct inode *inode = filp->f_dentry->d_inode; 726 dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); 727 mutex_lock(&inode->i_mutex); 728 err=nfsd_dosync(filp, filp->f_dentry, filp->f_op); 729 mutex_unlock(&inode->i_mutex); 730 731 return err; 732 } 733 734 int 735 nfsd_sync_dir(struct dentry *dp) 736 { 737 return nfsd_dosync(NULL, dp, dp->d_inode->i_fop); 738 } 739 740 /* 741 * Obtain the readahead parameters for the file 742 * specified by (dev, ino). 743 */ 744 static DEFINE_SPINLOCK(ra_lock); 745 746 static inline struct raparms * 747 nfsd_get_raparms(dev_t dev, ino_t ino) 748 { 749 struct raparms *ra, **rap, **frap = NULL; 750 int depth = 0; 751 752 spin_lock(&ra_lock); 753 for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) { 754 if (ra->p_ino == ino && ra->p_dev == dev) 755 goto found; 756 depth++; 757 if (ra->p_count == 0) 758 frap = rap; 759 } 760 depth = nfsdstats.ra_size*11/10; 761 if (!frap) { 762 spin_unlock(&ra_lock); 763 return NULL; 764 } 765 rap = frap; 766 ra = *frap; 767 ra->p_dev = dev; 768 ra->p_ino = ino; 769 ra->p_set = 0; 770 found: 771 if (rap != &raparm_cache) { 772 *rap = ra->p_next; 773 ra->p_next = raparm_cache; 774 raparm_cache = ra; 775 } 776 ra->p_count++; 777 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 778 spin_unlock(&ra_lock); 779 return ra; 780 } 781 782 /* 783 * Grab and keep cached pages assosiated with a file in the svc_rqst 784 * so that they can be passed to the netowork sendmsg/sendpage routines 785 * directrly. They will be released after the sending has completed. 786 */ 787 static int 788 nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size) 789 { 790 unsigned long count = desc->count; 791 struct svc_rqst *rqstp = desc->arg.data; 792 793 if (size > count) 794 size = count; 795 796 if (rqstp->rq_res.page_len == 0) { 797 get_page(page); 798 rqstp->rq_respages[rqstp->rq_resused++] = page; 799 rqstp->rq_res.page_base = offset; 800 rqstp->rq_res.page_len = size; 801 } else if (page != rqstp->rq_respages[rqstp->rq_resused-1]) { 802 get_page(page); 803 rqstp->rq_respages[rqstp->rq_resused++] = page; 804 rqstp->rq_res.page_len += size; 805 } else { 806 rqstp->rq_res.page_len += size; 807 } 808 809 desc->count = count - size; 810 desc->written += size; 811 return size; 812 } 813 814 static int 815 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 816 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 817 { 818 struct inode *inode; 819 struct raparms *ra; 820 mm_segment_t oldfs; 821 int err; 822 823 err = nfserr_perm; 824 inode = file->f_dentry->d_inode; 825 #ifdef MSNFS 826 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 827 (!lock_may_read(inode, offset, *count))) 828 goto out; 829 #endif 830 831 /* Get readahead parameters */ 832 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 833 834 if (ra && ra->p_set) 835 file->f_ra = ra->p_ra; 836 837 if (file->f_op->sendfile) { 838 svc_pushback_unused_pages(rqstp); 839 err = file->f_op->sendfile(file, &offset, *count, 840 nfsd_read_actor, rqstp); 841 } else { 842 oldfs = get_fs(); 843 set_fs(KERNEL_DS); 844 err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 845 set_fs(oldfs); 846 } 847 848 /* Write back readahead params */ 849 if (ra) { 850 spin_lock(&ra_lock); 851 ra->p_ra = file->f_ra; 852 ra->p_set = 1; 853 ra->p_count--; 854 spin_unlock(&ra_lock); 855 } 856 857 if (err >= 0) { 858 nfsdstats.io_read += err; 859 *count = err; 860 err = 0; 861 fsnotify_access(file->f_dentry); 862 } else 863 err = nfserrno(err); 864 out: 865 return err; 866 } 867 868 static void kill_suid(struct dentry *dentry) 869 { 870 struct iattr ia; 871 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID; 872 873 mutex_lock(&dentry->d_inode->i_mutex); 874 notify_change(dentry, &ia); 875 mutex_unlock(&dentry->d_inode->i_mutex); 876 } 877 878 static int 879 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 880 loff_t offset, struct kvec *vec, int vlen, 881 unsigned long cnt, int *stablep) 882 { 883 struct svc_export *exp; 884 struct dentry *dentry; 885 struct inode *inode; 886 mm_segment_t oldfs; 887 int err = 0; 888 int stable = *stablep; 889 890 #ifdef MSNFS 891 err = nfserr_perm; 892 893 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 894 (!lock_may_write(file->f_dentry->d_inode, offset, cnt))) 895 goto out; 896 #endif 897 898 dentry = file->f_dentry; 899 inode = dentry->d_inode; 900 exp = fhp->fh_export; 901 902 /* 903 * Request sync writes if 904 * - the sync export option has been set, or 905 * - the client requested O_SYNC behavior (NFSv3 feature). 906 * - The file system doesn't support fsync(). 907 * When gathered writes have been configured for this volume, 908 * flushing the data to disk is handled separately below. 909 */ 910 911 if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */ 912 stable = 2; 913 *stablep = 2; /* FILE_SYNC */ 914 } 915 916 if (!EX_ISSYNC(exp)) 917 stable = 0; 918 if (stable && !EX_WGATHER(exp)) 919 file->f_flags |= O_SYNC; 920 921 /* Write the data. */ 922 oldfs = get_fs(); set_fs(KERNEL_DS); 923 err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 924 set_fs(oldfs); 925 if (err >= 0) { 926 nfsdstats.io_write += cnt; 927 fsnotify_modify(file->f_dentry); 928 } 929 930 /* clear setuid/setgid flag after write */ 931 if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) 932 kill_suid(dentry); 933 934 if (err >= 0 && stable) { 935 static ino_t last_ino; 936 static dev_t last_dev; 937 938 /* 939 * Gathered writes: If another process is currently 940 * writing to the file, there's a high chance 941 * this is another nfsd (triggered by a bulk write 942 * from a client's biod). Rather than syncing the 943 * file with each write request, we sleep for 10 msec. 944 * 945 * I don't know if this roughly approximates 946 * C. Juszak's idea of gathered writes, but it's a 947 * nice and simple solution (IMHO), and it seems to 948 * work:-) 949 */ 950 if (EX_WGATHER(exp)) { 951 if (atomic_read(&inode->i_writecount) > 1 952 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 953 dprintk("nfsd: write defer %d\n", current->pid); 954 msleep(10); 955 dprintk("nfsd: write resume %d\n", current->pid); 956 } 957 958 if (inode->i_state & I_DIRTY) { 959 dprintk("nfsd: write sync %d\n", current->pid); 960 err=nfsd_sync(file); 961 } 962 #if 0 963 wake_up(&inode->i_wait); 964 #endif 965 } 966 last_ino = inode->i_ino; 967 last_dev = inode->i_sb->s_dev; 968 } 969 970 dprintk("nfsd: write complete err=%d\n", err); 971 if (err >= 0) 972 err = 0; 973 else 974 err = nfserrno(err); 975 out: 976 return err; 977 } 978 979 /* 980 * Read data from a file. count must contain the requested read count 981 * on entry. On return, *count contains the number of bytes actually read. 982 * N.B. After this call fhp needs an fh_put 983 */ 984 int 985 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 986 loff_t offset, struct kvec *vec, int vlen, 987 unsigned long *count) 988 { 989 int err; 990 991 if (file) { 992 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 993 MAY_READ|MAY_OWNER_OVERRIDE); 994 if (err) 995 goto out; 996 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 997 } else { 998 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); 999 if (err) 1000 goto out; 1001 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1002 nfsd_close(file); 1003 } 1004 out: 1005 return err; 1006 } 1007 1008 /* 1009 * Write data to a file. 1010 * The stable flag requests synchronous writes. 1011 * N.B. After this call fhp needs an fh_put 1012 */ 1013 int 1014 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1015 loff_t offset, struct kvec *vec, int vlen, unsigned long cnt, 1016 int *stablep) 1017 { 1018 int err = 0; 1019 1020 if (file) { 1021 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 1022 MAY_WRITE|MAY_OWNER_OVERRIDE); 1023 if (err) 1024 goto out; 1025 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1026 stablep); 1027 } else { 1028 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file); 1029 if (err) 1030 goto out; 1031 1032 if (cnt) 1033 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1034 cnt, stablep); 1035 nfsd_close(file); 1036 } 1037 out: 1038 return err; 1039 } 1040 1041 #ifdef CONFIG_NFSD_V3 1042 /* 1043 * Commit all pending writes to stable storage. 1044 * Strictly speaking, we could sync just the indicated file region here, 1045 * but there's currently no way we can ask the VFS to do so. 1046 * 1047 * Unfortunately we cannot lock the file to make sure we return full WCC 1048 * data to the client, as locking happens lower down in the filesystem. 1049 */ 1050 int 1051 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1052 loff_t offset, unsigned long count) 1053 { 1054 struct file *file; 1055 int err; 1056 1057 if ((u64)count > ~(u64)offset) 1058 return nfserr_inval; 1059 1060 if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0) 1061 return err; 1062 if (EX_ISSYNC(fhp->fh_export)) { 1063 if (file->f_op && file->f_op->fsync) { 1064 err = nfserrno(nfsd_sync(file)); 1065 } else { 1066 err = nfserr_notsupp; 1067 } 1068 } 1069 1070 nfsd_close(file); 1071 return err; 1072 } 1073 #endif /* CONFIG_NFSD_V3 */ 1074 1075 /* 1076 * Create a file (regular, directory, device, fifo); UNIX sockets 1077 * not yet implemented. 1078 * If the response fh has been verified, the parent directory should 1079 * already be locked. Note that the parent directory is left locked. 1080 * 1081 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1082 */ 1083 int 1084 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1085 char *fname, int flen, struct iattr *iap, 1086 int type, dev_t rdev, struct svc_fh *resfhp) 1087 { 1088 struct dentry *dentry, *dchild = NULL; 1089 struct inode *dirp; 1090 int err; 1091 1092 err = nfserr_perm; 1093 if (!flen) 1094 goto out; 1095 err = nfserr_exist; 1096 if (isdotent(fname, flen)) 1097 goto out; 1098 1099 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1100 if (err) 1101 goto out; 1102 1103 dentry = fhp->fh_dentry; 1104 dirp = dentry->d_inode; 1105 1106 err = nfserr_notdir; 1107 if(!dirp->i_op || !dirp->i_op->lookup) 1108 goto out; 1109 /* 1110 * Check whether the response file handle has been verified yet. 1111 * If it has, the parent directory should already be locked. 1112 */ 1113 if (!resfhp->fh_dentry) { 1114 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1115 fh_lock(fhp); 1116 dchild = lookup_one_len(fname, dentry, flen); 1117 err = PTR_ERR(dchild); 1118 if (IS_ERR(dchild)) 1119 goto out_nfserr; 1120 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1121 if (err) 1122 goto out; 1123 } else { 1124 /* called from nfsd_proc_create */ 1125 dchild = dget(resfhp->fh_dentry); 1126 if (!fhp->fh_locked) { 1127 /* not actually possible */ 1128 printk(KERN_ERR 1129 "nfsd_create: parent %s/%s not locked!\n", 1130 dentry->d_parent->d_name.name, 1131 dentry->d_name.name); 1132 err = nfserr_io; 1133 goto out; 1134 } 1135 } 1136 /* 1137 * Make sure the child dentry is still negative ... 1138 */ 1139 err = nfserr_exist; 1140 if (dchild->d_inode) { 1141 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1142 dentry->d_name.name, dchild->d_name.name); 1143 goto out; 1144 } 1145 1146 if (!(iap->ia_valid & ATTR_MODE)) 1147 iap->ia_mode = 0; 1148 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1149 1150 /* 1151 * Get the dir op function pointer. 1152 */ 1153 err = nfserr_perm; 1154 switch (type) { 1155 case S_IFREG: 1156 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1157 break; 1158 case S_IFDIR: 1159 err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1160 break; 1161 case S_IFCHR: 1162 case S_IFBLK: 1163 case S_IFIFO: 1164 case S_IFSOCK: 1165 err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1166 break; 1167 default: 1168 printk("nfsd: bad file type %o in nfsd_create\n", type); 1169 err = -EINVAL; 1170 } 1171 if (err < 0) 1172 goto out_nfserr; 1173 1174 if (EX_ISSYNC(fhp->fh_export)) { 1175 err = nfserrno(nfsd_sync_dir(dentry)); 1176 write_inode_now(dchild->d_inode, 1); 1177 } 1178 1179 1180 /* Set file attributes. Mode has already been set and 1181 * setting uid/gid works only for root. Irix appears to 1182 * send along the gid when it tries to implement setgid 1183 * directories via NFS. 1184 */ 1185 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) { 1186 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1187 if (err2) 1188 err = err2; 1189 } 1190 /* 1191 * Update the file handle to get the new inode info. 1192 */ 1193 if (!err) 1194 err = fh_update(resfhp); 1195 out: 1196 if (dchild && !IS_ERR(dchild)) 1197 dput(dchild); 1198 return err; 1199 1200 out_nfserr: 1201 err = nfserrno(err); 1202 goto out; 1203 } 1204 1205 #ifdef CONFIG_NFSD_V3 1206 /* 1207 * NFSv3 version of nfsd_create 1208 */ 1209 int 1210 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1211 char *fname, int flen, struct iattr *iap, 1212 struct svc_fh *resfhp, int createmode, u32 *verifier, 1213 int *truncp) 1214 { 1215 struct dentry *dentry, *dchild = NULL; 1216 struct inode *dirp; 1217 int err; 1218 __u32 v_mtime=0, v_atime=0; 1219 int v_mode=0; 1220 1221 err = nfserr_perm; 1222 if (!flen) 1223 goto out; 1224 err = nfserr_exist; 1225 if (isdotent(fname, flen)) 1226 goto out; 1227 if (!(iap->ia_valid & ATTR_MODE)) 1228 iap->ia_mode = 0; 1229 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1230 if (err) 1231 goto out; 1232 1233 dentry = fhp->fh_dentry; 1234 dirp = dentry->d_inode; 1235 1236 /* Get all the sanity checks out of the way before 1237 * we lock the parent. */ 1238 err = nfserr_notdir; 1239 if(!dirp->i_op || !dirp->i_op->lookup) 1240 goto out; 1241 fh_lock(fhp); 1242 1243 /* 1244 * Compose the response file handle. 1245 */ 1246 dchild = lookup_one_len(fname, dentry, flen); 1247 err = PTR_ERR(dchild); 1248 if (IS_ERR(dchild)) 1249 goto out_nfserr; 1250 1251 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1252 if (err) 1253 goto out; 1254 1255 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1256 /* while the verifier would fit in mtime+atime, 1257 * solaris7 gets confused (bugid 4218508) if these have 1258 * the high bit set, so we use the mode as well 1259 */ 1260 v_mtime = verifier[0]&0x7fffffff; 1261 v_atime = verifier[1]&0x7fffffff; 1262 v_mode = S_IFREG 1263 | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */ 1264 | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */ 1265 ; 1266 } 1267 1268 if (dchild->d_inode) { 1269 err = 0; 1270 1271 switch (createmode) { 1272 case NFS3_CREATE_UNCHECKED: 1273 if (! S_ISREG(dchild->d_inode->i_mode)) 1274 err = nfserr_exist; 1275 else if (truncp) { 1276 /* in nfsv4, we need to treat this case a little 1277 * differently. we don't want to truncate the 1278 * file now; this would be wrong if the OPEN 1279 * fails for some other reason. furthermore, 1280 * if the size is nonzero, we should ignore it 1281 * according to spec! 1282 */ 1283 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1284 } 1285 else { 1286 iap->ia_valid &= ATTR_SIZE; 1287 goto set_attr; 1288 } 1289 break; 1290 case NFS3_CREATE_EXCLUSIVE: 1291 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1292 && dchild->d_inode->i_atime.tv_sec == v_atime 1293 && dchild->d_inode->i_mode == v_mode 1294 && dchild->d_inode->i_size == 0 ) 1295 break; 1296 /* fallthru */ 1297 case NFS3_CREATE_GUARDED: 1298 err = nfserr_exist; 1299 } 1300 goto out; 1301 } 1302 1303 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1304 if (err < 0) 1305 goto out_nfserr; 1306 1307 if (EX_ISSYNC(fhp->fh_export)) { 1308 err = nfserrno(nfsd_sync_dir(dentry)); 1309 /* setattr will sync the child (or not) */ 1310 } 1311 1312 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1313 /* Cram the verifier into atime/mtime/mode */ 1314 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1315 | ATTR_MTIME_SET|ATTR_ATIME_SET 1316 | ATTR_MODE; 1317 /* XXX someone who knows this better please fix it for nsec */ 1318 iap->ia_mtime.tv_sec = v_mtime; 1319 iap->ia_atime.tv_sec = v_atime; 1320 iap->ia_mtime.tv_nsec = 0; 1321 iap->ia_atime.tv_nsec = 0; 1322 iap->ia_mode = v_mode; 1323 } 1324 1325 /* Set file attributes. 1326 * Mode has already been set but we might need to reset it 1327 * for CREATE_EXCLUSIVE 1328 * Irix appears to send along the gid when it tries to 1329 * implement setgid directories via NFS. Clear out all that cruft. 1330 */ 1331 set_attr: 1332 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0) { 1333 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1334 if (err2) 1335 err = err2; 1336 } 1337 1338 /* 1339 * Update the filehandle to get the new inode info. 1340 */ 1341 if (!err) 1342 err = fh_update(resfhp); 1343 1344 out: 1345 fh_unlock(fhp); 1346 if (dchild && !IS_ERR(dchild)) 1347 dput(dchild); 1348 return err; 1349 1350 out_nfserr: 1351 err = nfserrno(err); 1352 goto out; 1353 } 1354 #endif /* CONFIG_NFSD_V3 */ 1355 1356 /* 1357 * Read a symlink. On entry, *lenp must contain the maximum path length that 1358 * fits into the buffer. On return, it contains the true length. 1359 * N.B. After this call fhp needs an fh_put 1360 */ 1361 int 1362 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1363 { 1364 struct dentry *dentry; 1365 struct inode *inode; 1366 mm_segment_t oldfs; 1367 int err; 1368 1369 err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP); 1370 if (err) 1371 goto out; 1372 1373 dentry = fhp->fh_dentry; 1374 inode = dentry->d_inode; 1375 1376 err = nfserr_inval; 1377 if (!inode->i_op || !inode->i_op->readlink) 1378 goto out; 1379 1380 touch_atime(fhp->fh_export->ex_mnt, dentry); 1381 /* N.B. Why does this call need a get_fs()?? 1382 * Remove the set_fs and watch the fireworks:-) --okir 1383 */ 1384 1385 oldfs = get_fs(); set_fs(KERNEL_DS); 1386 err = inode->i_op->readlink(dentry, buf, *lenp); 1387 set_fs(oldfs); 1388 1389 if (err < 0) 1390 goto out_nfserr; 1391 *lenp = err; 1392 err = 0; 1393 out: 1394 return err; 1395 1396 out_nfserr: 1397 err = nfserrno(err); 1398 goto out; 1399 } 1400 1401 /* 1402 * Create a symlink and look up its inode 1403 * N.B. After this call _both_ fhp and resfhp need an fh_put 1404 */ 1405 int 1406 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1407 char *fname, int flen, 1408 char *path, int plen, 1409 struct svc_fh *resfhp, 1410 struct iattr *iap) 1411 { 1412 struct dentry *dentry, *dnew; 1413 int err, cerr; 1414 umode_t mode; 1415 1416 err = nfserr_noent; 1417 if (!flen || !plen) 1418 goto out; 1419 err = nfserr_exist; 1420 if (isdotent(fname, flen)) 1421 goto out; 1422 1423 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1424 if (err) 1425 goto out; 1426 fh_lock(fhp); 1427 dentry = fhp->fh_dentry; 1428 dnew = lookup_one_len(fname, dentry, flen); 1429 err = PTR_ERR(dnew); 1430 if (IS_ERR(dnew)) 1431 goto out_nfserr; 1432 1433 mode = S_IALLUGO; 1434 /* Only the MODE ATTRibute is even vaguely meaningful */ 1435 if (iap && (iap->ia_valid & ATTR_MODE)) 1436 mode = iap->ia_mode & S_IALLUGO; 1437 1438 if (unlikely(path[plen] != 0)) { 1439 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1440 if (path_alloced == NULL) 1441 err = -ENOMEM; 1442 else { 1443 strncpy(path_alloced, path, plen); 1444 path_alloced[plen] = 0; 1445 err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode); 1446 kfree(path_alloced); 1447 } 1448 } else 1449 err = vfs_symlink(dentry->d_inode, dnew, path, mode); 1450 1451 if (!err) 1452 if (EX_ISSYNC(fhp->fh_export)) 1453 err = nfsd_sync_dir(dentry); 1454 if (err) 1455 err = nfserrno(err); 1456 fh_unlock(fhp); 1457 1458 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1459 dput(dnew); 1460 if (err==0) err = cerr; 1461 out: 1462 return err; 1463 1464 out_nfserr: 1465 err = nfserrno(err); 1466 goto out; 1467 } 1468 1469 /* 1470 * Create a hardlink 1471 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1472 */ 1473 int 1474 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1475 char *name, int len, struct svc_fh *tfhp) 1476 { 1477 struct dentry *ddir, *dnew, *dold; 1478 struct inode *dirp, *dest; 1479 int err; 1480 1481 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE); 1482 if (err) 1483 goto out; 1484 err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP); 1485 if (err) 1486 goto out; 1487 1488 err = nfserr_perm; 1489 if (!len) 1490 goto out; 1491 err = nfserr_exist; 1492 if (isdotent(name, len)) 1493 goto out; 1494 1495 fh_lock(ffhp); 1496 ddir = ffhp->fh_dentry; 1497 dirp = ddir->d_inode; 1498 1499 dnew = lookup_one_len(name, ddir, len); 1500 err = PTR_ERR(dnew); 1501 if (IS_ERR(dnew)) 1502 goto out_nfserr; 1503 1504 dold = tfhp->fh_dentry; 1505 dest = dold->d_inode; 1506 1507 err = vfs_link(dold, dirp, dnew); 1508 if (!err) { 1509 if (EX_ISSYNC(ffhp->fh_export)) { 1510 err = nfserrno(nfsd_sync_dir(ddir)); 1511 write_inode_now(dest, 1); 1512 } 1513 } else { 1514 if (err == -EXDEV && rqstp->rq_vers == 2) 1515 err = nfserr_acces; 1516 else 1517 err = nfserrno(err); 1518 } 1519 1520 fh_unlock(ffhp); 1521 dput(dnew); 1522 out: 1523 return err; 1524 1525 out_nfserr: 1526 err = nfserrno(err); 1527 goto out; 1528 } 1529 1530 /* 1531 * Rename a file 1532 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1533 */ 1534 int 1535 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1536 struct svc_fh *tfhp, char *tname, int tlen) 1537 { 1538 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1539 struct inode *fdir, *tdir; 1540 int err; 1541 1542 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE); 1543 if (err) 1544 goto out; 1545 err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE); 1546 if (err) 1547 goto out; 1548 1549 fdentry = ffhp->fh_dentry; 1550 fdir = fdentry->d_inode; 1551 1552 tdentry = tfhp->fh_dentry; 1553 tdir = tdentry->d_inode; 1554 1555 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1556 if (fdir->i_sb != tdir->i_sb) 1557 goto out; 1558 1559 err = nfserr_perm; 1560 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1561 goto out; 1562 1563 /* cannot use fh_lock as we need deadlock protective ordering 1564 * so do it by hand */ 1565 trap = lock_rename(tdentry, fdentry); 1566 ffhp->fh_locked = tfhp->fh_locked = 1; 1567 fill_pre_wcc(ffhp); 1568 fill_pre_wcc(tfhp); 1569 1570 odentry = lookup_one_len(fname, fdentry, flen); 1571 err = PTR_ERR(odentry); 1572 if (IS_ERR(odentry)) 1573 goto out_nfserr; 1574 1575 err = -ENOENT; 1576 if (!odentry->d_inode) 1577 goto out_dput_old; 1578 err = -EINVAL; 1579 if (odentry == trap) 1580 goto out_dput_old; 1581 1582 ndentry = lookup_one_len(tname, tdentry, tlen); 1583 err = PTR_ERR(ndentry); 1584 if (IS_ERR(ndentry)) 1585 goto out_dput_old; 1586 err = -ENOTEMPTY; 1587 if (ndentry == trap) 1588 goto out_dput_new; 1589 1590 #ifdef MSNFS 1591 if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1592 ((atomic_read(&odentry->d_count) > 1) 1593 || (atomic_read(&ndentry->d_count) > 1))) { 1594 err = -EPERM; 1595 } else 1596 #endif 1597 err = vfs_rename(fdir, odentry, tdir, ndentry); 1598 if (!err && EX_ISSYNC(tfhp->fh_export)) { 1599 err = nfsd_sync_dir(tdentry); 1600 if (!err) 1601 err = nfsd_sync_dir(fdentry); 1602 } 1603 1604 out_dput_new: 1605 dput(ndentry); 1606 out_dput_old: 1607 dput(odentry); 1608 out_nfserr: 1609 if (err) 1610 err = nfserrno(err); 1611 1612 /* we cannot reply on fh_unlock on the two filehandles, 1613 * as that would do the wrong thing if the two directories 1614 * were the same, so again we do it by hand 1615 */ 1616 fill_post_wcc(ffhp); 1617 fill_post_wcc(tfhp); 1618 unlock_rename(tdentry, fdentry); 1619 ffhp->fh_locked = tfhp->fh_locked = 0; 1620 1621 out: 1622 return err; 1623 } 1624 1625 /* 1626 * Unlink a file or directory 1627 * N.B. After this call fhp needs an fh_put 1628 */ 1629 int 1630 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1631 char *fname, int flen) 1632 { 1633 struct dentry *dentry, *rdentry; 1634 struct inode *dirp; 1635 int err; 1636 1637 err = nfserr_acces; 1638 if (!flen || isdotent(fname, flen)) 1639 goto out; 1640 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE); 1641 if (err) 1642 goto out; 1643 1644 fh_lock(fhp); 1645 dentry = fhp->fh_dentry; 1646 dirp = dentry->d_inode; 1647 1648 rdentry = lookup_one_len(fname, dentry, flen); 1649 err = PTR_ERR(rdentry); 1650 if (IS_ERR(rdentry)) 1651 goto out_nfserr; 1652 1653 if (!rdentry->d_inode) { 1654 dput(rdentry); 1655 err = nfserr_noent; 1656 goto out; 1657 } 1658 1659 if (!type) 1660 type = rdentry->d_inode->i_mode & S_IFMT; 1661 1662 if (type != S_IFDIR) { /* It's UNLINK */ 1663 #ifdef MSNFS 1664 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1665 (atomic_read(&rdentry->d_count) > 1)) { 1666 err = -EPERM; 1667 } else 1668 #endif 1669 err = vfs_unlink(dirp, rdentry); 1670 } else { /* It's RMDIR */ 1671 err = vfs_rmdir(dirp, rdentry); 1672 } 1673 1674 dput(rdentry); 1675 1676 if (err == 0 && 1677 EX_ISSYNC(fhp->fh_export)) 1678 err = nfsd_sync_dir(dentry); 1679 1680 out_nfserr: 1681 err = nfserrno(err); 1682 out: 1683 return err; 1684 } 1685 1686 /* 1687 * Read entries from a directory. 1688 * The NFSv3/4 verifier we ignore for now. 1689 */ 1690 int 1691 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1692 struct readdir_cd *cdp, encode_dent_fn func) 1693 { 1694 int err; 1695 struct file *file; 1696 loff_t offset = *offsetp; 1697 1698 err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); 1699 if (err) 1700 goto out; 1701 1702 offset = vfs_llseek(file, offset, 0); 1703 if (offset < 0) { 1704 err = nfserrno((int)offset); 1705 goto out_close; 1706 } 1707 1708 /* 1709 * Read the directory entries. This silly loop is necessary because 1710 * readdir() is not guaranteed to fill up the entire buffer, but 1711 * may choose to do less. 1712 */ 1713 1714 do { 1715 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1716 err = vfs_readdir(file, (filldir_t) func, cdp); 1717 } while (err >=0 && cdp->err == nfs_ok); 1718 if (err) 1719 err = nfserrno(err); 1720 else 1721 err = cdp->err; 1722 *offsetp = vfs_llseek(file, 0, 1); 1723 1724 if (err == nfserr_eof || err == nfserr_toosmall) 1725 err = nfs_ok; /* can still be found in ->err */ 1726 out_close: 1727 nfsd_close(file); 1728 out: 1729 return err; 1730 } 1731 1732 /* 1733 * Get file system stats 1734 * N.B. After this call fhp needs an fh_put 1735 */ 1736 int 1737 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat) 1738 { 1739 int err = fh_verify(rqstp, fhp, 0, MAY_NOP); 1740 if (!err && vfs_statfs(fhp->fh_dentry->d_inode->i_sb,stat)) 1741 err = nfserr_io; 1742 return err; 1743 } 1744 1745 /* 1746 * Check for a user's access permissions to this inode. 1747 */ 1748 int 1749 nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc) 1750 { 1751 struct inode *inode = dentry->d_inode; 1752 int err; 1753 1754 if (acc == MAY_NOP) 1755 return 0; 1756 #if 0 1757 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 1758 acc, 1759 (acc & MAY_READ)? " read" : "", 1760 (acc & MAY_WRITE)? " write" : "", 1761 (acc & MAY_EXEC)? " exec" : "", 1762 (acc & MAY_SATTR)? " sattr" : "", 1763 (acc & MAY_TRUNC)? " trunc" : "", 1764 (acc & MAY_LOCK)? " lock" : "", 1765 (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "", 1766 inode->i_mode, 1767 IS_IMMUTABLE(inode)? " immut" : "", 1768 IS_APPEND(inode)? " append" : "", 1769 IS_RDONLY(inode)? " ro" : ""); 1770 dprintk(" owner %d/%d user %d/%d\n", 1771 inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); 1772 #endif 1773 1774 /* Normally we reject any write/sattr etc access on a read-only file 1775 * system. But if it is IRIX doing check on write-access for a 1776 * device special file, we ignore rofs. 1777 */ 1778 if (!(acc & MAY_LOCAL_ACCESS)) 1779 if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { 1780 if (EX_RDONLY(exp) || IS_RDONLY(inode)) 1781 return nfserr_rofs; 1782 if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) 1783 return nfserr_perm; 1784 } 1785 if ((acc & MAY_TRUNC) && IS_APPEND(inode)) 1786 return nfserr_perm; 1787 1788 if (acc & MAY_LOCK) { 1789 /* If we cannot rely on authentication in NLM requests, 1790 * just allow locks, otherwise require read permission, or 1791 * ownership 1792 */ 1793 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 1794 return 0; 1795 else 1796 acc = MAY_READ | MAY_OWNER_OVERRIDE; 1797 } 1798 /* 1799 * The file owner always gets access permission for accesses that 1800 * would normally be checked at open time. This is to make 1801 * file access work even when the client has done a fchmod(fd, 0). 1802 * 1803 * However, `cp foo bar' should fail nevertheless when bar is 1804 * readonly. A sensible way to do this might be to reject all 1805 * attempts to truncate a read-only file, because a creat() call 1806 * always implies file truncation. 1807 * ... but this isn't really fair. A process may reasonably call 1808 * ftruncate on an open file descriptor on a file with perm 000. 1809 * We must trust the client to do permission checking - using "ACCESS" 1810 * with NFSv3. 1811 */ 1812 if ((acc & MAY_OWNER_OVERRIDE) && 1813 inode->i_uid == current->fsuid) 1814 return 0; 1815 1816 err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL); 1817 1818 /* Allow read access to binaries even when mode 111 */ 1819 if (err == -EACCES && S_ISREG(inode->i_mode) && 1820 acc == (MAY_READ | MAY_OWNER_OVERRIDE)) 1821 err = permission(inode, MAY_EXEC, NULL); 1822 1823 return err? nfserrno(err) : 0; 1824 } 1825 1826 void 1827 nfsd_racache_shutdown(void) 1828 { 1829 if (!raparm_cache) 1830 return; 1831 dprintk("nfsd: freeing readahead buffers.\n"); 1832 kfree(raparml); 1833 raparm_cache = raparml = NULL; 1834 } 1835 /* 1836 * Initialize readahead param cache 1837 */ 1838 int 1839 nfsd_racache_init(int cache_size) 1840 { 1841 int i; 1842 1843 if (raparm_cache) 1844 return 0; 1845 raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); 1846 1847 if (raparml != NULL) { 1848 dprintk("nfsd: allocating %d readahead buffers.\n", 1849 cache_size); 1850 memset(raparml, 0, sizeof(struct raparms) * cache_size); 1851 for (i = 0; i < cache_size - 1; i++) { 1852 raparml[i].p_next = raparml + i + 1; 1853 } 1854 raparm_cache = raparml; 1855 } else { 1856 printk(KERN_WARNING 1857 "nfsd: Could not allocate memory read-ahead cache.\n"); 1858 return -ENOMEM; 1859 } 1860 nfsdstats.ra_size = cache_size; 1861 return 0; 1862 } 1863 1864 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 1865 struct posix_acl * 1866 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 1867 { 1868 struct inode *inode = fhp->fh_dentry->d_inode; 1869 char *name; 1870 void *value = NULL; 1871 ssize_t size; 1872 struct posix_acl *acl; 1873 1874 if (!IS_POSIXACL(inode)) 1875 return ERR_PTR(-EOPNOTSUPP); 1876 1877 switch (type) { 1878 case ACL_TYPE_ACCESS: 1879 name = POSIX_ACL_XATTR_ACCESS; 1880 break; 1881 case ACL_TYPE_DEFAULT: 1882 name = POSIX_ACL_XATTR_DEFAULT; 1883 break; 1884 default: 1885 return ERR_PTR(-EOPNOTSUPP); 1886 } 1887 1888 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 1889 if (size < 0) 1890 return ERR_PTR(size); 1891 1892 acl = posix_acl_from_xattr(value, size); 1893 kfree(value); 1894 return acl; 1895 } 1896 1897 int 1898 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 1899 { 1900 struct inode *inode = fhp->fh_dentry->d_inode; 1901 char *name; 1902 void *value = NULL; 1903 size_t size; 1904 int error; 1905 1906 if (!IS_POSIXACL(inode) || !inode->i_op || 1907 !inode->i_op->setxattr || !inode->i_op->removexattr) 1908 return -EOPNOTSUPP; 1909 switch(type) { 1910 case ACL_TYPE_ACCESS: 1911 name = POSIX_ACL_XATTR_ACCESS; 1912 break; 1913 case ACL_TYPE_DEFAULT: 1914 name = POSIX_ACL_XATTR_DEFAULT; 1915 break; 1916 default: 1917 return -EOPNOTSUPP; 1918 } 1919 1920 if (acl && acl->a_count) { 1921 size = posix_acl_xattr_size(acl->a_count); 1922 value = kmalloc(size, GFP_KERNEL); 1923 if (!value) 1924 return -ENOMEM; 1925 error = posix_acl_to_xattr(acl, value, size); 1926 if (error < 0) 1927 goto getout; 1928 size = error; 1929 } else 1930 size = 0; 1931 1932 if (size) 1933 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 1934 else { 1935 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 1936 error = 0; 1937 else { 1938 error = vfs_removexattr(fhp->fh_dentry, name); 1939 if (error == -ENODATA) 1940 error = 0; 1941 } 1942 } 1943 1944 getout: 1945 kfree(value); 1946 return error; 1947 } 1948 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 1949