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 if (access & MAY_READ) 677 flags = O_RDWR|O_LARGEFILE; 678 else 679 flags = O_WRONLY|O_LARGEFILE; 680 681 DQUOT_INIT(inode); 682 } 683 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags); 684 if (IS_ERR(*filp)) 685 err = PTR_ERR(*filp); 686 out_nfserr: 687 if (err) 688 err = nfserrno(err); 689 out: 690 return err; 691 } 692 693 /* 694 * Close a file. 695 */ 696 void 697 nfsd_close(struct file *filp) 698 { 699 fput(filp); 700 } 701 702 /* 703 * Sync a file 704 * As this calls fsync (not fdatasync) there is no need for a write_inode 705 * after it. 706 */ 707 static inline int nfsd_dosync(struct file *filp, struct dentry *dp, 708 const struct file_operations *fop) 709 { 710 struct inode *inode = dp->d_inode; 711 int (*fsync) (struct file *, struct dentry *, int); 712 int err; 713 714 err = filemap_fdatawrite(inode->i_mapping); 715 if (err == 0 && fop && (fsync = fop->fsync)) 716 err = fsync(filp, dp, 0); 717 if (err == 0) 718 err = filemap_fdatawait(inode->i_mapping); 719 720 return err; 721 } 722 723 724 static int 725 nfsd_sync(struct file *filp) 726 { 727 int err; 728 struct inode *inode = filp->f_dentry->d_inode; 729 dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); 730 mutex_lock(&inode->i_mutex); 731 err=nfsd_dosync(filp, filp->f_dentry, filp->f_op); 732 mutex_unlock(&inode->i_mutex); 733 734 return err; 735 } 736 737 int 738 nfsd_sync_dir(struct dentry *dp) 739 { 740 return nfsd_dosync(NULL, dp, dp->d_inode->i_fop); 741 } 742 743 /* 744 * Obtain the readahead parameters for the file 745 * specified by (dev, ino). 746 */ 747 static DEFINE_SPINLOCK(ra_lock); 748 749 static inline struct raparms * 750 nfsd_get_raparms(dev_t dev, ino_t ino) 751 { 752 struct raparms *ra, **rap, **frap = NULL; 753 int depth = 0; 754 755 spin_lock(&ra_lock); 756 for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) { 757 if (ra->p_ino == ino && ra->p_dev == dev) 758 goto found; 759 depth++; 760 if (ra->p_count == 0) 761 frap = rap; 762 } 763 depth = nfsdstats.ra_size*11/10; 764 if (!frap) { 765 spin_unlock(&ra_lock); 766 return NULL; 767 } 768 rap = frap; 769 ra = *frap; 770 ra->p_dev = dev; 771 ra->p_ino = ino; 772 ra->p_set = 0; 773 found: 774 if (rap != &raparm_cache) { 775 *rap = ra->p_next; 776 ra->p_next = raparm_cache; 777 raparm_cache = ra; 778 } 779 ra->p_count++; 780 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 781 spin_unlock(&ra_lock); 782 return ra; 783 } 784 785 /* 786 * Grab and keep cached pages assosiated with a file in the svc_rqst 787 * so that they can be passed to the netowork sendmsg/sendpage routines 788 * directrly. They will be released after the sending has completed. 789 */ 790 static int 791 nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size) 792 { 793 unsigned long count = desc->count; 794 struct svc_rqst *rqstp = desc->arg.data; 795 796 if (size > count) 797 size = count; 798 799 if (rqstp->rq_res.page_len == 0) { 800 get_page(page); 801 rqstp->rq_respages[rqstp->rq_resused++] = page; 802 rqstp->rq_res.page_base = offset; 803 rqstp->rq_res.page_len = size; 804 } else if (page != rqstp->rq_respages[rqstp->rq_resused-1]) { 805 get_page(page); 806 rqstp->rq_respages[rqstp->rq_resused++] = page; 807 rqstp->rq_res.page_len += size; 808 } else { 809 rqstp->rq_res.page_len += size; 810 } 811 812 desc->count = count - size; 813 desc->written += size; 814 return size; 815 } 816 817 static int 818 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 819 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 820 { 821 struct inode *inode; 822 struct raparms *ra; 823 mm_segment_t oldfs; 824 int err; 825 826 err = nfserr_perm; 827 inode = file->f_dentry->d_inode; 828 #ifdef MSNFS 829 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 830 (!lock_may_read(inode, offset, *count))) 831 goto out; 832 #endif 833 834 /* Get readahead parameters */ 835 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 836 837 if (ra && ra->p_set) 838 file->f_ra = ra->p_ra; 839 840 if (file->f_op->sendfile && rqstp->rq_sendfile_ok) { 841 svc_pushback_unused_pages(rqstp); 842 err = file->f_op->sendfile(file, &offset, *count, 843 nfsd_read_actor, rqstp); 844 } else { 845 oldfs = get_fs(); 846 set_fs(KERNEL_DS); 847 err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 848 set_fs(oldfs); 849 } 850 851 /* Write back readahead params */ 852 if (ra) { 853 spin_lock(&ra_lock); 854 ra->p_ra = file->f_ra; 855 ra->p_set = 1; 856 ra->p_count--; 857 spin_unlock(&ra_lock); 858 } 859 860 if (err >= 0) { 861 nfsdstats.io_read += err; 862 *count = err; 863 err = 0; 864 fsnotify_access(file->f_dentry); 865 } else 866 err = nfserrno(err); 867 out: 868 return err; 869 } 870 871 static void kill_suid(struct dentry *dentry) 872 { 873 struct iattr ia; 874 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID; 875 876 mutex_lock(&dentry->d_inode->i_mutex); 877 notify_change(dentry, &ia); 878 mutex_unlock(&dentry->d_inode->i_mutex); 879 } 880 881 static int 882 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 883 loff_t offset, struct kvec *vec, int vlen, 884 unsigned long cnt, int *stablep) 885 { 886 struct svc_export *exp; 887 struct dentry *dentry; 888 struct inode *inode; 889 mm_segment_t oldfs; 890 int err = 0; 891 int stable = *stablep; 892 893 #ifdef MSNFS 894 err = nfserr_perm; 895 896 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 897 (!lock_may_write(file->f_dentry->d_inode, offset, cnt))) 898 goto out; 899 #endif 900 901 dentry = file->f_dentry; 902 inode = dentry->d_inode; 903 exp = fhp->fh_export; 904 905 /* 906 * Request sync writes if 907 * - the sync export option has been set, or 908 * - the client requested O_SYNC behavior (NFSv3 feature). 909 * - The file system doesn't support fsync(). 910 * When gathered writes have been configured for this volume, 911 * flushing the data to disk is handled separately below. 912 */ 913 914 if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */ 915 stable = 2; 916 *stablep = 2; /* FILE_SYNC */ 917 } 918 919 if (!EX_ISSYNC(exp)) 920 stable = 0; 921 if (stable && !EX_WGATHER(exp)) 922 file->f_flags |= O_SYNC; 923 924 /* Write the data. */ 925 oldfs = get_fs(); set_fs(KERNEL_DS); 926 err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 927 set_fs(oldfs); 928 if (err >= 0) { 929 nfsdstats.io_write += cnt; 930 fsnotify_modify(file->f_dentry); 931 } 932 933 /* clear setuid/setgid flag after write */ 934 if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) 935 kill_suid(dentry); 936 937 if (err >= 0 && stable) { 938 static ino_t last_ino; 939 static dev_t last_dev; 940 941 /* 942 * Gathered writes: If another process is currently 943 * writing to the file, there's a high chance 944 * this is another nfsd (triggered by a bulk write 945 * from a client's biod). Rather than syncing the 946 * file with each write request, we sleep for 10 msec. 947 * 948 * I don't know if this roughly approximates 949 * C. Juszak's idea of gathered writes, but it's a 950 * nice and simple solution (IMHO), and it seems to 951 * work:-) 952 */ 953 if (EX_WGATHER(exp)) { 954 if (atomic_read(&inode->i_writecount) > 1 955 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 956 dprintk("nfsd: write defer %d\n", current->pid); 957 msleep(10); 958 dprintk("nfsd: write resume %d\n", current->pid); 959 } 960 961 if (inode->i_state & I_DIRTY) { 962 dprintk("nfsd: write sync %d\n", current->pid); 963 err=nfsd_sync(file); 964 } 965 #if 0 966 wake_up(&inode->i_wait); 967 #endif 968 } 969 last_ino = inode->i_ino; 970 last_dev = inode->i_sb->s_dev; 971 } 972 973 dprintk("nfsd: write complete err=%d\n", err); 974 if (err >= 0) 975 err = 0; 976 else 977 err = nfserrno(err); 978 out: 979 return err; 980 } 981 982 /* 983 * Read data from a file. count must contain the requested read count 984 * on entry. On return, *count contains the number of bytes actually read. 985 * N.B. After this call fhp needs an fh_put 986 */ 987 int 988 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 989 loff_t offset, struct kvec *vec, int vlen, 990 unsigned long *count) 991 { 992 int err; 993 994 if (file) { 995 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 996 MAY_READ|MAY_OWNER_OVERRIDE); 997 if (err) 998 goto out; 999 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1000 } else { 1001 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); 1002 if (err) 1003 goto out; 1004 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1005 nfsd_close(file); 1006 } 1007 out: 1008 return err; 1009 } 1010 1011 /* 1012 * Write data to a file. 1013 * The stable flag requests synchronous writes. 1014 * N.B. After this call fhp needs an fh_put 1015 */ 1016 int 1017 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1018 loff_t offset, struct kvec *vec, int vlen, unsigned long cnt, 1019 int *stablep) 1020 { 1021 int err = 0; 1022 1023 if (file) { 1024 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 1025 MAY_WRITE|MAY_OWNER_OVERRIDE); 1026 if (err) 1027 goto out; 1028 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1029 stablep); 1030 } else { 1031 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file); 1032 if (err) 1033 goto out; 1034 1035 if (cnt) 1036 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1037 cnt, stablep); 1038 nfsd_close(file); 1039 } 1040 out: 1041 return err; 1042 } 1043 1044 #ifdef CONFIG_NFSD_V3 1045 /* 1046 * Commit all pending writes to stable storage. 1047 * Strictly speaking, we could sync just the indicated file region here, 1048 * but there's currently no way we can ask the VFS to do so. 1049 * 1050 * Unfortunately we cannot lock the file to make sure we return full WCC 1051 * data to the client, as locking happens lower down in the filesystem. 1052 */ 1053 int 1054 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1055 loff_t offset, unsigned long count) 1056 { 1057 struct file *file; 1058 int err; 1059 1060 if ((u64)count > ~(u64)offset) 1061 return nfserr_inval; 1062 1063 if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0) 1064 return err; 1065 if (EX_ISSYNC(fhp->fh_export)) { 1066 if (file->f_op && file->f_op->fsync) { 1067 err = nfserrno(nfsd_sync(file)); 1068 } else { 1069 err = nfserr_notsupp; 1070 } 1071 } 1072 1073 nfsd_close(file); 1074 return err; 1075 } 1076 #endif /* CONFIG_NFSD_V3 */ 1077 1078 /* 1079 * Create a file (regular, directory, device, fifo); UNIX sockets 1080 * not yet implemented. 1081 * If the response fh has been verified, the parent directory should 1082 * already be locked. Note that the parent directory is left locked. 1083 * 1084 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1085 */ 1086 int 1087 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1088 char *fname, int flen, struct iattr *iap, 1089 int type, dev_t rdev, struct svc_fh *resfhp) 1090 { 1091 struct dentry *dentry, *dchild = NULL; 1092 struct inode *dirp; 1093 int err; 1094 1095 err = nfserr_perm; 1096 if (!flen) 1097 goto out; 1098 err = nfserr_exist; 1099 if (isdotent(fname, flen)) 1100 goto out; 1101 1102 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1103 if (err) 1104 goto out; 1105 1106 dentry = fhp->fh_dentry; 1107 dirp = dentry->d_inode; 1108 1109 err = nfserr_notdir; 1110 if(!dirp->i_op || !dirp->i_op->lookup) 1111 goto out; 1112 /* 1113 * Check whether the response file handle has been verified yet. 1114 * If it has, the parent directory should already be locked. 1115 */ 1116 if (!resfhp->fh_dentry) { 1117 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1118 fh_lock(fhp); 1119 dchild = lookup_one_len(fname, dentry, flen); 1120 err = PTR_ERR(dchild); 1121 if (IS_ERR(dchild)) 1122 goto out_nfserr; 1123 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1124 if (err) 1125 goto out; 1126 } else { 1127 /* called from nfsd_proc_create */ 1128 dchild = dget(resfhp->fh_dentry); 1129 if (!fhp->fh_locked) { 1130 /* not actually possible */ 1131 printk(KERN_ERR 1132 "nfsd_create: parent %s/%s not locked!\n", 1133 dentry->d_parent->d_name.name, 1134 dentry->d_name.name); 1135 err = nfserr_io; 1136 goto out; 1137 } 1138 } 1139 /* 1140 * Make sure the child dentry is still negative ... 1141 */ 1142 err = nfserr_exist; 1143 if (dchild->d_inode) { 1144 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1145 dentry->d_name.name, dchild->d_name.name); 1146 goto out; 1147 } 1148 1149 if (!(iap->ia_valid & ATTR_MODE)) 1150 iap->ia_mode = 0; 1151 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1152 1153 /* 1154 * Get the dir op function pointer. 1155 */ 1156 err = nfserr_perm; 1157 switch (type) { 1158 case S_IFREG: 1159 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1160 break; 1161 case S_IFDIR: 1162 err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1163 break; 1164 case S_IFCHR: 1165 case S_IFBLK: 1166 case S_IFIFO: 1167 case S_IFSOCK: 1168 err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1169 break; 1170 default: 1171 printk("nfsd: bad file type %o in nfsd_create\n", type); 1172 err = -EINVAL; 1173 } 1174 if (err < 0) 1175 goto out_nfserr; 1176 1177 if (EX_ISSYNC(fhp->fh_export)) { 1178 err = nfserrno(nfsd_sync_dir(dentry)); 1179 write_inode_now(dchild->d_inode, 1); 1180 } 1181 1182 1183 /* Set file attributes. Mode has already been set and 1184 * setting uid/gid works only for root. Irix appears to 1185 * send along the gid when it tries to implement setgid 1186 * directories via NFS. 1187 */ 1188 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) { 1189 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1190 if (err2) 1191 err = err2; 1192 } 1193 /* 1194 * Update the file handle to get the new inode info. 1195 */ 1196 if (!err) 1197 err = fh_update(resfhp); 1198 out: 1199 if (dchild && !IS_ERR(dchild)) 1200 dput(dchild); 1201 return err; 1202 1203 out_nfserr: 1204 err = nfserrno(err); 1205 goto out; 1206 } 1207 1208 #ifdef CONFIG_NFSD_V3 1209 /* 1210 * NFSv3 version of nfsd_create 1211 */ 1212 int 1213 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1214 char *fname, int flen, struct iattr *iap, 1215 struct svc_fh *resfhp, int createmode, u32 *verifier, 1216 int *truncp) 1217 { 1218 struct dentry *dentry, *dchild = NULL; 1219 struct inode *dirp; 1220 int err; 1221 __u32 v_mtime=0, v_atime=0; 1222 int v_mode=0; 1223 1224 err = nfserr_perm; 1225 if (!flen) 1226 goto out; 1227 err = nfserr_exist; 1228 if (isdotent(fname, flen)) 1229 goto out; 1230 if (!(iap->ia_valid & ATTR_MODE)) 1231 iap->ia_mode = 0; 1232 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1233 if (err) 1234 goto out; 1235 1236 dentry = fhp->fh_dentry; 1237 dirp = dentry->d_inode; 1238 1239 /* Get all the sanity checks out of the way before 1240 * we lock the parent. */ 1241 err = nfserr_notdir; 1242 if(!dirp->i_op || !dirp->i_op->lookup) 1243 goto out; 1244 fh_lock(fhp); 1245 1246 /* 1247 * Compose the response file handle. 1248 */ 1249 dchild = lookup_one_len(fname, dentry, flen); 1250 err = PTR_ERR(dchild); 1251 if (IS_ERR(dchild)) 1252 goto out_nfserr; 1253 1254 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1255 if (err) 1256 goto out; 1257 1258 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1259 /* while the verifier would fit in mtime+atime, 1260 * solaris7 gets confused (bugid 4218508) if these have 1261 * the high bit set, so we use the mode as well 1262 */ 1263 v_mtime = verifier[0]&0x7fffffff; 1264 v_atime = verifier[1]&0x7fffffff; 1265 v_mode = S_IFREG 1266 | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */ 1267 | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */ 1268 ; 1269 } 1270 1271 if (dchild->d_inode) { 1272 err = 0; 1273 1274 switch (createmode) { 1275 case NFS3_CREATE_UNCHECKED: 1276 if (! S_ISREG(dchild->d_inode->i_mode)) 1277 err = nfserr_exist; 1278 else if (truncp) { 1279 /* in nfsv4, we need to treat this case a little 1280 * differently. we don't want to truncate the 1281 * file now; this would be wrong if the OPEN 1282 * fails for some other reason. furthermore, 1283 * if the size is nonzero, we should ignore it 1284 * according to spec! 1285 */ 1286 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1287 } 1288 else { 1289 iap->ia_valid &= ATTR_SIZE; 1290 goto set_attr; 1291 } 1292 break; 1293 case NFS3_CREATE_EXCLUSIVE: 1294 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1295 && dchild->d_inode->i_atime.tv_sec == v_atime 1296 && dchild->d_inode->i_mode == v_mode 1297 && dchild->d_inode->i_size == 0 ) 1298 break; 1299 /* fallthru */ 1300 case NFS3_CREATE_GUARDED: 1301 err = nfserr_exist; 1302 } 1303 goto out; 1304 } 1305 1306 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1307 if (err < 0) 1308 goto out_nfserr; 1309 1310 if (EX_ISSYNC(fhp->fh_export)) { 1311 err = nfserrno(nfsd_sync_dir(dentry)); 1312 /* setattr will sync the child (or not) */ 1313 } 1314 1315 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1316 /* Cram the verifier into atime/mtime/mode */ 1317 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1318 | ATTR_MTIME_SET|ATTR_ATIME_SET 1319 | ATTR_MODE; 1320 /* XXX someone who knows this better please fix it for nsec */ 1321 iap->ia_mtime.tv_sec = v_mtime; 1322 iap->ia_atime.tv_sec = v_atime; 1323 iap->ia_mtime.tv_nsec = 0; 1324 iap->ia_atime.tv_nsec = 0; 1325 iap->ia_mode = v_mode; 1326 } 1327 1328 /* Set file attributes. 1329 * Mode has already been set but we might need to reset it 1330 * for CREATE_EXCLUSIVE 1331 * Irix appears to send along the gid when it tries to 1332 * implement setgid directories via NFS. Clear out all that cruft. 1333 */ 1334 set_attr: 1335 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0) { 1336 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1337 if (err2) 1338 err = err2; 1339 } 1340 1341 /* 1342 * Update the filehandle to get the new inode info. 1343 */ 1344 if (!err) 1345 err = fh_update(resfhp); 1346 1347 out: 1348 fh_unlock(fhp); 1349 if (dchild && !IS_ERR(dchild)) 1350 dput(dchild); 1351 return err; 1352 1353 out_nfserr: 1354 err = nfserrno(err); 1355 goto out; 1356 } 1357 #endif /* CONFIG_NFSD_V3 */ 1358 1359 /* 1360 * Read a symlink. On entry, *lenp must contain the maximum path length that 1361 * fits into the buffer. On return, it contains the true length. 1362 * N.B. After this call fhp needs an fh_put 1363 */ 1364 int 1365 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1366 { 1367 struct dentry *dentry; 1368 struct inode *inode; 1369 mm_segment_t oldfs; 1370 int err; 1371 1372 err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP); 1373 if (err) 1374 goto out; 1375 1376 dentry = fhp->fh_dentry; 1377 inode = dentry->d_inode; 1378 1379 err = nfserr_inval; 1380 if (!inode->i_op || !inode->i_op->readlink) 1381 goto out; 1382 1383 touch_atime(fhp->fh_export->ex_mnt, dentry); 1384 /* N.B. Why does this call need a get_fs()?? 1385 * Remove the set_fs and watch the fireworks:-) --okir 1386 */ 1387 1388 oldfs = get_fs(); set_fs(KERNEL_DS); 1389 err = inode->i_op->readlink(dentry, buf, *lenp); 1390 set_fs(oldfs); 1391 1392 if (err < 0) 1393 goto out_nfserr; 1394 *lenp = err; 1395 err = 0; 1396 out: 1397 return err; 1398 1399 out_nfserr: 1400 err = nfserrno(err); 1401 goto out; 1402 } 1403 1404 /* 1405 * Create a symlink and look up its inode 1406 * N.B. After this call _both_ fhp and resfhp need an fh_put 1407 */ 1408 int 1409 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1410 char *fname, int flen, 1411 char *path, int plen, 1412 struct svc_fh *resfhp, 1413 struct iattr *iap) 1414 { 1415 struct dentry *dentry, *dnew; 1416 int err, cerr; 1417 umode_t mode; 1418 1419 err = nfserr_noent; 1420 if (!flen || !plen) 1421 goto out; 1422 err = nfserr_exist; 1423 if (isdotent(fname, flen)) 1424 goto out; 1425 1426 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1427 if (err) 1428 goto out; 1429 fh_lock(fhp); 1430 dentry = fhp->fh_dentry; 1431 dnew = lookup_one_len(fname, dentry, flen); 1432 err = PTR_ERR(dnew); 1433 if (IS_ERR(dnew)) 1434 goto out_nfserr; 1435 1436 mode = S_IALLUGO; 1437 /* Only the MODE ATTRibute is even vaguely meaningful */ 1438 if (iap && (iap->ia_valid & ATTR_MODE)) 1439 mode = iap->ia_mode & S_IALLUGO; 1440 1441 if (unlikely(path[plen] != 0)) { 1442 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1443 if (path_alloced == NULL) 1444 err = -ENOMEM; 1445 else { 1446 strncpy(path_alloced, path, plen); 1447 path_alloced[plen] = 0; 1448 err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode); 1449 kfree(path_alloced); 1450 } 1451 } else 1452 err = vfs_symlink(dentry->d_inode, dnew, path, mode); 1453 1454 if (!err) 1455 if (EX_ISSYNC(fhp->fh_export)) 1456 err = nfsd_sync_dir(dentry); 1457 if (err) 1458 err = nfserrno(err); 1459 fh_unlock(fhp); 1460 1461 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1462 dput(dnew); 1463 if (err==0) err = cerr; 1464 out: 1465 return err; 1466 1467 out_nfserr: 1468 err = nfserrno(err); 1469 goto out; 1470 } 1471 1472 /* 1473 * Create a hardlink 1474 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1475 */ 1476 int 1477 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1478 char *name, int len, struct svc_fh *tfhp) 1479 { 1480 struct dentry *ddir, *dnew, *dold; 1481 struct inode *dirp, *dest; 1482 int err; 1483 1484 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE); 1485 if (err) 1486 goto out; 1487 err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP); 1488 if (err) 1489 goto out; 1490 1491 err = nfserr_perm; 1492 if (!len) 1493 goto out; 1494 err = nfserr_exist; 1495 if (isdotent(name, len)) 1496 goto out; 1497 1498 fh_lock(ffhp); 1499 ddir = ffhp->fh_dentry; 1500 dirp = ddir->d_inode; 1501 1502 dnew = lookup_one_len(name, ddir, len); 1503 err = PTR_ERR(dnew); 1504 if (IS_ERR(dnew)) 1505 goto out_nfserr; 1506 1507 dold = tfhp->fh_dentry; 1508 dest = dold->d_inode; 1509 1510 err = vfs_link(dold, dirp, dnew); 1511 if (!err) { 1512 if (EX_ISSYNC(ffhp->fh_export)) { 1513 err = nfserrno(nfsd_sync_dir(ddir)); 1514 write_inode_now(dest, 1); 1515 } 1516 } else { 1517 if (err == -EXDEV && rqstp->rq_vers == 2) 1518 err = nfserr_acces; 1519 else 1520 err = nfserrno(err); 1521 } 1522 1523 dput(dnew); 1524 out_unlock: 1525 fh_unlock(ffhp); 1526 out: 1527 return err; 1528 1529 out_nfserr: 1530 err = nfserrno(err); 1531 goto out_unlock; 1532 } 1533 1534 /* 1535 * Rename a file 1536 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1537 */ 1538 int 1539 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1540 struct svc_fh *tfhp, char *tname, int tlen) 1541 { 1542 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1543 struct inode *fdir, *tdir; 1544 int err; 1545 1546 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE); 1547 if (err) 1548 goto out; 1549 err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE); 1550 if (err) 1551 goto out; 1552 1553 fdentry = ffhp->fh_dentry; 1554 fdir = fdentry->d_inode; 1555 1556 tdentry = tfhp->fh_dentry; 1557 tdir = tdentry->d_inode; 1558 1559 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1560 if (ffhp->fh_export != tfhp->fh_export) 1561 goto out; 1562 1563 err = nfserr_perm; 1564 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1565 goto out; 1566 1567 /* cannot use fh_lock as we need deadlock protective ordering 1568 * so do it by hand */ 1569 trap = lock_rename(tdentry, fdentry); 1570 ffhp->fh_locked = tfhp->fh_locked = 1; 1571 fill_pre_wcc(ffhp); 1572 fill_pre_wcc(tfhp); 1573 1574 odentry = lookup_one_len(fname, fdentry, flen); 1575 err = PTR_ERR(odentry); 1576 if (IS_ERR(odentry)) 1577 goto out_nfserr; 1578 1579 err = -ENOENT; 1580 if (!odentry->d_inode) 1581 goto out_dput_old; 1582 err = -EINVAL; 1583 if (odentry == trap) 1584 goto out_dput_old; 1585 1586 ndentry = lookup_one_len(tname, tdentry, tlen); 1587 err = PTR_ERR(ndentry); 1588 if (IS_ERR(ndentry)) 1589 goto out_dput_old; 1590 err = -ENOTEMPTY; 1591 if (ndentry == trap) 1592 goto out_dput_new; 1593 1594 #ifdef MSNFS 1595 if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1596 ((atomic_read(&odentry->d_count) > 1) 1597 || (atomic_read(&ndentry->d_count) > 1))) { 1598 err = -EPERM; 1599 } else 1600 #endif 1601 err = vfs_rename(fdir, odentry, tdir, ndentry); 1602 if (!err && EX_ISSYNC(tfhp->fh_export)) { 1603 err = nfsd_sync_dir(tdentry); 1604 if (!err) 1605 err = nfsd_sync_dir(fdentry); 1606 } 1607 1608 out_dput_new: 1609 dput(ndentry); 1610 out_dput_old: 1611 dput(odentry); 1612 out_nfserr: 1613 if (err) 1614 err = nfserrno(err); 1615 1616 /* we cannot reply on fh_unlock on the two filehandles, 1617 * as that would do the wrong thing if the two directories 1618 * were the same, so again we do it by hand 1619 */ 1620 fill_post_wcc(ffhp); 1621 fill_post_wcc(tfhp); 1622 unlock_rename(tdentry, fdentry); 1623 ffhp->fh_locked = tfhp->fh_locked = 0; 1624 1625 out: 1626 return err; 1627 } 1628 1629 /* 1630 * Unlink a file or directory 1631 * N.B. After this call fhp needs an fh_put 1632 */ 1633 int 1634 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1635 char *fname, int flen) 1636 { 1637 struct dentry *dentry, *rdentry; 1638 struct inode *dirp; 1639 int err; 1640 1641 err = nfserr_acces; 1642 if (!flen || isdotent(fname, flen)) 1643 goto out; 1644 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE); 1645 if (err) 1646 goto out; 1647 1648 fh_lock(fhp); 1649 dentry = fhp->fh_dentry; 1650 dirp = dentry->d_inode; 1651 1652 rdentry = lookup_one_len(fname, dentry, flen); 1653 err = PTR_ERR(rdentry); 1654 if (IS_ERR(rdentry)) 1655 goto out_nfserr; 1656 1657 if (!rdentry->d_inode) { 1658 dput(rdentry); 1659 err = nfserr_noent; 1660 goto out; 1661 } 1662 1663 if (!type) 1664 type = rdentry->d_inode->i_mode & S_IFMT; 1665 1666 if (type != S_IFDIR) { /* It's UNLINK */ 1667 #ifdef MSNFS 1668 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1669 (atomic_read(&rdentry->d_count) > 1)) { 1670 err = -EPERM; 1671 } else 1672 #endif 1673 err = vfs_unlink(dirp, rdentry); 1674 } else { /* It's RMDIR */ 1675 err = vfs_rmdir(dirp, rdentry); 1676 } 1677 1678 dput(rdentry); 1679 1680 if (err == 0 && 1681 EX_ISSYNC(fhp->fh_export)) 1682 err = nfsd_sync_dir(dentry); 1683 1684 out_nfserr: 1685 err = nfserrno(err); 1686 out: 1687 return err; 1688 } 1689 1690 /* 1691 * Read entries from a directory. 1692 * The NFSv3/4 verifier we ignore for now. 1693 */ 1694 int 1695 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1696 struct readdir_cd *cdp, encode_dent_fn func) 1697 { 1698 int err; 1699 struct file *file; 1700 loff_t offset = *offsetp; 1701 1702 err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); 1703 if (err) 1704 goto out; 1705 1706 offset = vfs_llseek(file, offset, 0); 1707 if (offset < 0) { 1708 err = nfserrno((int)offset); 1709 goto out_close; 1710 } 1711 1712 /* 1713 * Read the directory entries. This silly loop is necessary because 1714 * readdir() is not guaranteed to fill up the entire buffer, but 1715 * may choose to do less. 1716 */ 1717 1718 do { 1719 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1720 err = vfs_readdir(file, (filldir_t) func, cdp); 1721 } while (err >=0 && cdp->err == nfs_ok); 1722 if (err) 1723 err = nfserrno(err); 1724 else 1725 err = cdp->err; 1726 *offsetp = vfs_llseek(file, 0, 1); 1727 1728 if (err == nfserr_eof || err == nfserr_toosmall) 1729 err = nfs_ok; /* can still be found in ->err */ 1730 out_close: 1731 nfsd_close(file); 1732 out: 1733 return err; 1734 } 1735 1736 /* 1737 * Get file system stats 1738 * N.B. After this call fhp needs an fh_put 1739 */ 1740 int 1741 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat) 1742 { 1743 int err = fh_verify(rqstp, fhp, 0, MAY_NOP); 1744 if (!err && vfs_statfs(fhp->fh_dentry,stat)) 1745 err = nfserr_io; 1746 return err; 1747 } 1748 1749 /* 1750 * Check for a user's access permissions to this inode. 1751 */ 1752 int 1753 nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc) 1754 { 1755 struct inode *inode = dentry->d_inode; 1756 int err; 1757 1758 if (acc == MAY_NOP) 1759 return 0; 1760 #if 0 1761 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 1762 acc, 1763 (acc & MAY_READ)? " read" : "", 1764 (acc & MAY_WRITE)? " write" : "", 1765 (acc & MAY_EXEC)? " exec" : "", 1766 (acc & MAY_SATTR)? " sattr" : "", 1767 (acc & MAY_TRUNC)? " trunc" : "", 1768 (acc & MAY_LOCK)? " lock" : "", 1769 (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "", 1770 inode->i_mode, 1771 IS_IMMUTABLE(inode)? " immut" : "", 1772 IS_APPEND(inode)? " append" : "", 1773 IS_RDONLY(inode)? " ro" : ""); 1774 dprintk(" owner %d/%d user %d/%d\n", 1775 inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); 1776 #endif 1777 1778 /* Normally we reject any write/sattr etc access on a read-only file 1779 * system. But if it is IRIX doing check on write-access for a 1780 * device special file, we ignore rofs. 1781 */ 1782 if (!(acc & MAY_LOCAL_ACCESS)) 1783 if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { 1784 if (EX_RDONLY(exp) || IS_RDONLY(inode)) 1785 return nfserr_rofs; 1786 if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) 1787 return nfserr_perm; 1788 } 1789 if ((acc & MAY_TRUNC) && IS_APPEND(inode)) 1790 return nfserr_perm; 1791 1792 if (acc & MAY_LOCK) { 1793 /* If we cannot rely on authentication in NLM requests, 1794 * just allow locks, otherwise require read permission, or 1795 * ownership 1796 */ 1797 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 1798 return 0; 1799 else 1800 acc = MAY_READ | MAY_OWNER_OVERRIDE; 1801 } 1802 /* 1803 * The file owner always gets access permission for accesses that 1804 * would normally be checked at open time. This is to make 1805 * file access work even when the client has done a fchmod(fd, 0). 1806 * 1807 * However, `cp foo bar' should fail nevertheless when bar is 1808 * readonly. A sensible way to do this might be to reject all 1809 * attempts to truncate a read-only file, because a creat() call 1810 * always implies file truncation. 1811 * ... but this isn't really fair. A process may reasonably call 1812 * ftruncate on an open file descriptor on a file with perm 000. 1813 * We must trust the client to do permission checking - using "ACCESS" 1814 * with NFSv3. 1815 */ 1816 if ((acc & MAY_OWNER_OVERRIDE) && 1817 inode->i_uid == current->fsuid) 1818 return 0; 1819 1820 err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL); 1821 1822 /* Allow read access to binaries even when mode 111 */ 1823 if (err == -EACCES && S_ISREG(inode->i_mode) && 1824 acc == (MAY_READ | MAY_OWNER_OVERRIDE)) 1825 err = permission(inode, MAY_EXEC, NULL); 1826 1827 return err? nfserrno(err) : 0; 1828 } 1829 1830 void 1831 nfsd_racache_shutdown(void) 1832 { 1833 if (!raparm_cache) 1834 return; 1835 dprintk("nfsd: freeing readahead buffers.\n"); 1836 kfree(raparml); 1837 raparm_cache = raparml = NULL; 1838 } 1839 /* 1840 * Initialize readahead param cache 1841 */ 1842 int 1843 nfsd_racache_init(int cache_size) 1844 { 1845 int i; 1846 1847 if (raparm_cache) 1848 return 0; 1849 raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); 1850 1851 if (raparml != NULL) { 1852 dprintk("nfsd: allocating %d readahead buffers.\n", 1853 cache_size); 1854 memset(raparml, 0, sizeof(struct raparms) * cache_size); 1855 for (i = 0; i < cache_size - 1; i++) { 1856 raparml[i].p_next = raparml + i + 1; 1857 } 1858 raparm_cache = raparml; 1859 } else { 1860 printk(KERN_WARNING 1861 "nfsd: Could not allocate memory read-ahead cache.\n"); 1862 return -ENOMEM; 1863 } 1864 nfsdstats.ra_size = cache_size; 1865 return 0; 1866 } 1867 1868 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 1869 struct posix_acl * 1870 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 1871 { 1872 struct inode *inode = fhp->fh_dentry->d_inode; 1873 char *name; 1874 void *value = NULL; 1875 ssize_t size; 1876 struct posix_acl *acl; 1877 1878 if (!IS_POSIXACL(inode)) 1879 return ERR_PTR(-EOPNOTSUPP); 1880 1881 switch (type) { 1882 case ACL_TYPE_ACCESS: 1883 name = POSIX_ACL_XATTR_ACCESS; 1884 break; 1885 case ACL_TYPE_DEFAULT: 1886 name = POSIX_ACL_XATTR_DEFAULT; 1887 break; 1888 default: 1889 return ERR_PTR(-EOPNOTSUPP); 1890 } 1891 1892 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 1893 if (size < 0) 1894 return ERR_PTR(size); 1895 1896 acl = posix_acl_from_xattr(value, size); 1897 kfree(value); 1898 return acl; 1899 } 1900 1901 int 1902 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 1903 { 1904 struct inode *inode = fhp->fh_dentry->d_inode; 1905 char *name; 1906 void *value = NULL; 1907 size_t size; 1908 int error; 1909 1910 if (!IS_POSIXACL(inode) || !inode->i_op || 1911 !inode->i_op->setxattr || !inode->i_op->removexattr) 1912 return -EOPNOTSUPP; 1913 switch(type) { 1914 case ACL_TYPE_ACCESS: 1915 name = POSIX_ACL_XATTR_ACCESS; 1916 break; 1917 case ACL_TYPE_DEFAULT: 1918 name = POSIX_ACL_XATTR_DEFAULT; 1919 break; 1920 default: 1921 return -EOPNOTSUPP; 1922 } 1923 1924 if (acl && acl->a_count) { 1925 size = posix_acl_xattr_size(acl->a_count); 1926 value = kmalloc(size, GFP_KERNEL); 1927 if (!value) 1928 return -ENOMEM; 1929 error = posix_acl_to_xattr(acl, value, size); 1930 if (error < 0) 1931 goto getout; 1932 size = error; 1933 } else 1934 size = 0; 1935 1936 if (size) 1937 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 1938 else { 1939 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 1940 error = 0; 1941 else { 1942 error = vfs_removexattr(fhp->fh_dentry, name); 1943 if (error == -ENODATA) 1944 error = 0; 1945 } 1946 } 1947 1948 getout: 1949 kfree(value); 1950 return error; 1951 } 1952 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 1953