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/string.h> 20 #include <linux/time.h> 21 #include <linux/errno.h> 22 #include <linux/fs.h> 23 #include <linux/file.h> 24 #include <linux/mount.h> 25 #include <linux/major.h> 26 #include <linux/ext2_fs.h> 27 #include <linux/proc_fs.h> 28 #include <linux/stat.h> 29 #include <linux/fcntl.h> 30 #include <linux/net.h> 31 #include <linux/unistd.h> 32 #include <linux/slab.h> 33 #include <linux/pagemap.h> 34 #include <linux/in.h> 35 #include <linux/module.h> 36 #include <linux/namei.h> 37 #include <linux/vfs.h> 38 #include <linux/delay.h> 39 #include <linux/sunrpc/svc.h> 40 #include <linux/nfsd/nfsd.h> 41 #ifdef CONFIG_NFSD_V3 42 #include <linux/nfs3.h> 43 #include <linux/nfsd/xdr3.h> 44 #endif /* CONFIG_NFSD_V3 */ 45 #include <linux/nfsd/nfsfh.h> 46 #include <linux/quotaops.h> 47 #include <linux/fsnotify.h> 48 #include <linux/posix_acl.h> 49 #include <linux/posix_acl_xattr.h> 50 #include <linux/xattr.h> 51 #ifdef CONFIG_NFSD_V4 52 #include <linux/nfs4.h> 53 #include <linux/nfs4_acl.h> 54 #include <linux/nfsd_idmap.h> 55 #include <linux/security.h> 56 #endif /* CONFIG_NFSD_V4 */ 57 58 #include <asm/uaccess.h> 59 60 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 61 #define NFSD_PARANOIA 62 63 64 /* We must ignore files (but only files) which might have mandatory 65 * locks on them because there is no way to know if the accesser has 66 * the lock. 67 */ 68 #define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i)) 69 70 /* 71 * This is a cache of readahead params that help us choose the proper 72 * readahead strategy. Initially, we set all readahead parameters to 0 73 * and let the VFS handle things. 74 * If you increase the number of cached files very much, you'll need to 75 * add a hash table here. 76 */ 77 struct raparms { 78 struct raparms *p_next; 79 unsigned int p_count; 80 ino_t p_ino; 81 dev_t p_dev; 82 int p_set; 83 struct file_ra_state p_ra; 84 }; 85 86 static struct raparms * raparml; 87 static struct raparms * raparm_cache; 88 89 /* 90 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 91 * a mount point. 92 * Returns -EAGAIN leaving *dpp and *expp unchanged, 93 * or nfs_ok having possibly changed *dpp and *expp 94 */ 95 int 96 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 97 struct svc_export **expp) 98 { 99 struct svc_export *exp = *expp, *exp2 = NULL; 100 struct dentry *dentry = *dpp; 101 struct vfsmount *mnt = mntget(exp->ex_mnt); 102 struct dentry *mounts = dget(dentry); 103 int err = nfs_ok; 104 105 while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)); 106 107 exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle); 108 if (IS_ERR(exp2)) { 109 err = PTR_ERR(exp2); 110 dput(mounts); 111 mntput(mnt); 112 goto out; 113 } 114 if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2))) { 115 /* successfully crossed mount point */ 116 exp_put(exp); 117 *expp = exp2; 118 dput(dentry); 119 *dpp = mounts; 120 } else { 121 if (exp2) exp_put(exp2); 122 dput(mounts); 123 } 124 mntput(mnt); 125 out: 126 return err; 127 } 128 129 /* 130 * Look up one component of a pathname. 131 * N.B. After this call _both_ fhp and resfh need an fh_put 132 * 133 * If the lookup would cross a mountpoint, and the mounted filesystem 134 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 135 * accepted as it stands and the mounted directory is 136 * returned. Otherwise the covered directory is returned. 137 * NOTE: this mountpoint crossing is not supported properly by all 138 * clients and is explicitly disallowed for NFSv3 139 * NeilBrown <neilb@cse.unsw.edu.au> 140 */ 141 int 142 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 143 int len, struct svc_fh *resfh) 144 { 145 struct svc_export *exp; 146 struct dentry *dparent; 147 struct dentry *dentry; 148 int err; 149 150 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 151 152 /* Obtain dentry and export. */ 153 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC); 154 if (err) 155 return err; 156 157 dparent = fhp->fh_dentry; 158 exp = fhp->fh_export; 159 exp_get(exp); 160 161 err = nfserr_acces; 162 163 /* Lookup the name, but don't follow links */ 164 if (isdotent(name, len)) { 165 if (len==1) 166 dentry = dget(dparent); 167 else if (dparent != exp->ex_dentry) { 168 dentry = dget_parent(dparent); 169 } else if (!EX_NOHIDE(exp)) 170 dentry = dget(dparent); /* .. == . just like at / */ 171 else { 172 /* checking mountpoint crossing is very different when stepping up */ 173 struct svc_export *exp2 = NULL; 174 struct dentry *dp; 175 struct vfsmount *mnt = mntget(exp->ex_mnt); 176 dentry = dget(dparent); 177 while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry)) 178 ; 179 dp = dget_parent(dentry); 180 dput(dentry); 181 dentry = dp; 182 183 exp2 = exp_parent(exp->ex_client, mnt, dentry, 184 &rqstp->rq_chandle); 185 if (IS_ERR(exp2)) { 186 err = PTR_ERR(exp2); 187 dput(dentry); 188 mntput(mnt); 189 goto out_nfserr; 190 } 191 if (!exp2) { 192 dput(dentry); 193 dentry = dget(dparent); 194 } else { 195 exp_put(exp); 196 exp = exp2; 197 } 198 mntput(mnt); 199 } 200 } else { 201 fh_lock(fhp); 202 dentry = lookup_one_len(name, dparent, len); 203 err = PTR_ERR(dentry); 204 if (IS_ERR(dentry)) 205 goto out_nfserr; 206 /* 207 * check if we have crossed a mount point ... 208 */ 209 if (d_mountpoint(dentry)) { 210 if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 211 dput(dentry); 212 goto out_nfserr; 213 } 214 } 215 } 216 /* 217 * Note: we compose the file handle now, but as the 218 * dentry may be negative, it may need to be updated. 219 */ 220 err = fh_compose(resfh, exp, dentry, fhp); 221 if (!err && !dentry->d_inode) 222 err = nfserr_noent; 223 dput(dentry); 224 out: 225 exp_put(exp); 226 return err; 227 228 out_nfserr: 229 err = nfserrno(err); 230 goto out; 231 } 232 233 /* 234 * Set various file attributes. 235 * N.B. After this call fhp needs an fh_put 236 */ 237 int 238 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 239 int check_guard, time_t guardtime) 240 { 241 struct dentry *dentry; 242 struct inode *inode; 243 int accmode = MAY_SATTR; 244 int ftype = 0; 245 int imode; 246 int err; 247 int size_change = 0; 248 249 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 250 accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE; 251 if (iap->ia_valid & ATTR_SIZE) 252 ftype = S_IFREG; 253 254 /* Get inode */ 255 err = fh_verify(rqstp, fhp, ftype, accmode); 256 if (err) 257 goto out; 258 259 dentry = fhp->fh_dentry; 260 inode = dentry->d_inode; 261 262 /* Ignore any mode updates on symlinks */ 263 if (S_ISLNK(inode->i_mode)) 264 iap->ia_valid &= ~ATTR_MODE; 265 266 if (!iap->ia_valid) 267 goto out; 268 269 /* NFSv2 does not differentiate between "set-[ac]time-to-now" 270 * which only requires access, and "set-[ac]time-to-X" which 271 * requires ownership. 272 * So if it looks like it might be "set both to the same time which 273 * is close to now", and if inode_change_ok fails, then we 274 * convert to "set to now" instead of "set to explicit time" 275 * 276 * We only call inode_change_ok as the last test as technically 277 * it is not an interface that we should be using. It is only 278 * valid if the filesystem does not define it's own i_op->setattr. 279 */ 280 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 281 #define MAX_TOUCH_TIME_ERROR (30*60) 282 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET 283 && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec 284 ) { 285 /* Looks probable. Now just make sure time is in the right ballpark. 286 * Solaris, at least, doesn't seem to care what the time request is. 287 * We require it be within 30 minutes of now. 288 */ 289 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 290 if (delta<0) delta = -delta; 291 if (delta < MAX_TOUCH_TIME_ERROR && 292 inode_change_ok(inode, iap) != 0) { 293 /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME 294 * this will cause notify_change to set these times to "now" 295 */ 296 iap->ia_valid &= ~BOTH_TIME_SET; 297 } 298 } 299 300 /* The size case is special. It changes the file as well as the attributes. */ 301 if (iap->ia_valid & ATTR_SIZE) { 302 if (iap->ia_size < inode->i_size) { 303 err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); 304 if (err) 305 goto out; 306 } 307 308 /* 309 * If we are changing the size of the file, then 310 * we need to break all leases. 311 */ 312 err = break_lease(inode, FMODE_WRITE | O_NONBLOCK); 313 if (err == -EWOULDBLOCK) 314 err = -ETIMEDOUT; 315 if (err) /* ENOMEM or EWOULDBLOCK */ 316 goto out_nfserr; 317 318 err = get_write_access(inode); 319 if (err) 320 goto out_nfserr; 321 322 size_change = 1; 323 err = locks_verify_truncate(inode, NULL, iap->ia_size); 324 if (err) { 325 put_write_access(inode); 326 goto out_nfserr; 327 } 328 DQUOT_INIT(inode); 329 } 330 331 imode = inode->i_mode; 332 if (iap->ia_valid & ATTR_MODE) { 333 iap->ia_mode &= S_IALLUGO; 334 imode = iap->ia_mode |= (imode & ~S_IALLUGO); 335 } 336 337 /* Revoke setuid/setgid bit on chown/chgrp */ 338 if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) 339 iap->ia_valid |= ATTR_KILL_SUID; 340 if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid) 341 iap->ia_valid |= ATTR_KILL_SGID; 342 343 /* Change the attributes. */ 344 345 iap->ia_valid |= ATTR_CTIME; 346 347 err = nfserr_notsync; 348 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 349 fh_lock(fhp); 350 err = notify_change(dentry, iap); 351 err = nfserrno(err); 352 fh_unlock(fhp); 353 } 354 if (size_change) 355 put_write_access(inode); 356 if (!err) 357 if (EX_ISSYNC(fhp->fh_export)) 358 write_inode_now(inode, 1); 359 out: 360 return err; 361 362 out_nfserr: 363 err = nfserrno(err); 364 goto out; 365 } 366 367 #if defined(CONFIG_NFSD_V2_ACL) || \ 368 defined(CONFIG_NFSD_V3_ACL) || \ 369 defined(CONFIG_NFSD_V4) 370 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 371 { 372 ssize_t buflen; 373 374 buflen = vfs_getxattr(dentry, key, NULL, 0); 375 if (buflen <= 0) 376 return buflen; 377 378 *buf = kmalloc(buflen, GFP_KERNEL); 379 if (!*buf) 380 return -ENOMEM; 381 382 return vfs_getxattr(dentry, key, *buf, buflen); 383 } 384 #endif 385 386 #if defined(CONFIG_NFSD_V4) 387 static int 388 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 389 { 390 int len; 391 size_t buflen; 392 char *buf = NULL; 393 int error = 0; 394 395 buflen = posix_acl_xattr_size(pacl->a_count); 396 buf = kmalloc(buflen, GFP_KERNEL); 397 error = -ENOMEM; 398 if (buf == NULL) 399 goto out; 400 401 len = posix_acl_to_xattr(pacl, buf, buflen); 402 if (len < 0) { 403 error = len; 404 goto out; 405 } 406 407 error = vfs_setxattr(dentry, key, buf, len, 0); 408 out: 409 kfree(buf); 410 return error; 411 } 412 413 int 414 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 415 struct nfs4_acl *acl) 416 { 417 int error; 418 struct dentry *dentry; 419 struct inode *inode; 420 struct posix_acl *pacl = NULL, *dpacl = NULL; 421 unsigned int flags = 0; 422 423 /* Get inode */ 424 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR); 425 if (error) 426 goto out; 427 428 dentry = fhp->fh_dentry; 429 inode = dentry->d_inode; 430 if (S_ISDIR(inode->i_mode)) 431 flags = NFS4_ACL_DIR; 432 433 error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 434 if (error == -EINVAL) { 435 error = nfserr_attrnotsupp; 436 goto out; 437 } else if (error < 0) 438 goto out_nfserr; 439 440 if (pacl) { 441 error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 442 if (error < 0) 443 goto out_nfserr; 444 } 445 446 if (dpacl) { 447 error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 448 if (error < 0) 449 goto out_nfserr; 450 } 451 452 error = nfs_ok; 453 454 out: 455 posix_acl_release(pacl); 456 posix_acl_release(dpacl); 457 return (error); 458 out_nfserr: 459 error = nfserrno(error); 460 goto out; 461 } 462 463 static struct posix_acl * 464 _get_posix_acl(struct dentry *dentry, char *key) 465 { 466 void *buf = NULL; 467 struct posix_acl *pacl = NULL; 468 int buflen; 469 470 buflen = nfsd_getxattr(dentry, key, &buf); 471 if (!buflen) 472 buflen = -ENODATA; 473 if (buflen <= 0) 474 return ERR_PTR(buflen); 475 476 pacl = posix_acl_from_xattr(buf, buflen); 477 kfree(buf); 478 return pacl; 479 } 480 481 int 482 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 483 { 484 struct inode *inode = dentry->d_inode; 485 int error = 0; 486 struct posix_acl *pacl = NULL, *dpacl = NULL; 487 unsigned int flags = 0; 488 489 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 490 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 491 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 492 if (IS_ERR(pacl)) { 493 error = PTR_ERR(pacl); 494 pacl = NULL; 495 goto out; 496 } 497 498 if (S_ISDIR(inode->i_mode)) { 499 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 500 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 501 dpacl = NULL; 502 else if (IS_ERR(dpacl)) { 503 error = PTR_ERR(dpacl); 504 dpacl = NULL; 505 goto out; 506 } 507 flags = NFS4_ACL_DIR; 508 } 509 510 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 511 if (IS_ERR(*acl)) { 512 error = PTR_ERR(*acl); 513 *acl = NULL; 514 } 515 out: 516 posix_acl_release(pacl); 517 posix_acl_release(dpacl); 518 return error; 519 } 520 521 #endif /* defined(CONFIG_NFS_V4) */ 522 523 #ifdef CONFIG_NFSD_V3 524 /* 525 * Check server access rights to a file system object 526 */ 527 struct accessmap { 528 u32 access; 529 int how; 530 }; 531 static struct accessmap nfs3_regaccess[] = { 532 { NFS3_ACCESS_READ, MAY_READ }, 533 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 534 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC }, 535 { NFS3_ACCESS_EXTEND, MAY_WRITE }, 536 537 { 0, 0 } 538 }; 539 540 static struct accessmap nfs3_diraccess[] = { 541 { NFS3_ACCESS_READ, MAY_READ }, 542 { NFS3_ACCESS_LOOKUP, MAY_EXEC }, 543 { NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC }, 544 { NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE }, 545 { NFS3_ACCESS_DELETE, MAY_REMOVE }, 546 547 { 0, 0 } 548 }; 549 550 static struct accessmap nfs3_anyaccess[] = { 551 /* Some clients - Solaris 2.6 at least, make an access call 552 * to the server to check for access for things like /dev/null 553 * (which really, the server doesn't care about). So 554 * We provide simple access checking for them, looking 555 * mainly at mode bits, and we make sure to ignore read-only 556 * filesystem checks 557 */ 558 { NFS3_ACCESS_READ, MAY_READ }, 559 { NFS3_ACCESS_EXECUTE, MAY_EXEC }, 560 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_LOCAL_ACCESS }, 561 { NFS3_ACCESS_EXTEND, MAY_WRITE|MAY_LOCAL_ACCESS }, 562 563 { 0, 0 } 564 }; 565 566 int 567 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 568 { 569 struct accessmap *map; 570 struct svc_export *export; 571 struct dentry *dentry; 572 u32 query, result = 0, sresult = 0; 573 unsigned int error; 574 575 error = fh_verify(rqstp, fhp, 0, MAY_NOP); 576 if (error) 577 goto out; 578 579 export = fhp->fh_export; 580 dentry = fhp->fh_dentry; 581 582 if (S_ISREG(dentry->d_inode->i_mode)) 583 map = nfs3_regaccess; 584 else if (S_ISDIR(dentry->d_inode->i_mode)) 585 map = nfs3_diraccess; 586 else 587 map = nfs3_anyaccess; 588 589 590 query = *access; 591 for (; map->access; map++) { 592 if (map->access & query) { 593 unsigned int err2; 594 595 sresult |= map->access; 596 597 err2 = nfsd_permission(export, dentry, map->how); 598 switch (err2) { 599 case nfs_ok: 600 result |= map->access; 601 break; 602 603 /* the following error codes just mean the access was not allowed, 604 * rather than an error occurred */ 605 case nfserr_rofs: 606 case nfserr_acces: 607 case nfserr_perm: 608 /* simply don't "or" in the access bit. */ 609 break; 610 default: 611 error = err2; 612 goto out; 613 } 614 } 615 } 616 *access = result; 617 if (supported) 618 *supported = sresult; 619 620 out: 621 return error; 622 } 623 #endif /* CONFIG_NFSD_V3 */ 624 625 626 627 /* 628 * Open an existing file or directory. 629 * The access argument indicates the type of open (read/write/lock) 630 * N.B. After this call fhp needs an fh_put 631 */ 632 int 633 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 634 int access, struct file **filp) 635 { 636 struct dentry *dentry; 637 struct inode *inode; 638 int flags = O_RDONLY|O_LARGEFILE, err; 639 640 /* 641 * If we get here, then the client has already done an "open", 642 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 643 * in case a chmod has now revoked permission. 644 */ 645 err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE); 646 if (err) 647 goto out; 648 649 dentry = fhp->fh_dentry; 650 inode = dentry->d_inode; 651 652 /* Disallow write access to files with the append-only bit set 653 * or any access when mandatory locking enabled 654 */ 655 err = nfserr_perm; 656 if (IS_APPEND(inode) && (access & MAY_WRITE)) 657 goto out; 658 if (IS_ISMNDLK(inode)) 659 goto out; 660 661 if (!inode->i_fop) 662 goto out; 663 664 /* 665 * Check to see if there are any leases on this file. 666 * This may block while leases are broken. 667 */ 668 err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0)); 669 if (err == -EWOULDBLOCK) 670 err = -ETIMEDOUT; 671 if (err) /* NOMEM or WOULDBLOCK */ 672 goto out_nfserr; 673 674 if (access & MAY_WRITE) { 675 if (access & MAY_READ) 676 flags = O_RDWR|O_LARGEFILE; 677 else 678 flags = O_WRONLY|O_LARGEFILE; 679 680 DQUOT_INIT(inode); 681 } 682 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags); 683 if (IS_ERR(*filp)) 684 err = PTR_ERR(*filp); 685 out_nfserr: 686 if (err) 687 err = nfserrno(err); 688 out: 689 return err; 690 } 691 692 /* 693 * Close a file. 694 */ 695 void 696 nfsd_close(struct file *filp) 697 { 698 fput(filp); 699 } 700 701 /* 702 * Sync a file 703 * As this calls fsync (not fdatasync) there is no need for a write_inode 704 * after it. 705 */ 706 static inline int nfsd_dosync(struct file *filp, struct dentry *dp, 707 const struct file_operations *fop) 708 { 709 struct inode *inode = dp->d_inode; 710 int (*fsync) (struct file *, struct dentry *, int); 711 int err; 712 713 err = filemap_fdatawrite(inode->i_mapping); 714 if (err == 0 && fop && (fsync = fop->fsync)) 715 err = fsync(filp, dp, 0); 716 if (err == 0) 717 err = filemap_fdatawait(inode->i_mapping); 718 719 return err; 720 } 721 722 723 static int 724 nfsd_sync(struct file *filp) 725 { 726 int err; 727 struct inode *inode = filp->f_dentry->d_inode; 728 dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); 729 mutex_lock(&inode->i_mutex); 730 err=nfsd_dosync(filp, filp->f_dentry, filp->f_op); 731 mutex_unlock(&inode->i_mutex); 732 733 return err; 734 } 735 736 int 737 nfsd_sync_dir(struct dentry *dp) 738 { 739 return nfsd_dosync(NULL, dp, dp->d_inode->i_fop); 740 } 741 742 /* 743 * Obtain the readahead parameters for the file 744 * specified by (dev, ino). 745 */ 746 static DEFINE_SPINLOCK(ra_lock); 747 748 static inline struct raparms * 749 nfsd_get_raparms(dev_t dev, ino_t ino) 750 { 751 struct raparms *ra, **rap, **frap = NULL; 752 int depth = 0; 753 754 spin_lock(&ra_lock); 755 for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) { 756 if (ra->p_ino == ino && ra->p_dev == dev) 757 goto found; 758 depth++; 759 if (ra->p_count == 0) 760 frap = rap; 761 } 762 depth = nfsdstats.ra_size*11/10; 763 if (!frap) { 764 spin_unlock(&ra_lock); 765 return NULL; 766 } 767 rap = frap; 768 ra = *frap; 769 ra->p_dev = dev; 770 ra->p_ino = ino; 771 ra->p_set = 0; 772 found: 773 if (rap != &raparm_cache) { 774 *rap = ra->p_next; 775 ra->p_next = raparm_cache; 776 raparm_cache = ra; 777 } 778 ra->p_count++; 779 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 780 spin_unlock(&ra_lock); 781 return ra; 782 } 783 784 /* 785 * Grab and keep cached pages assosiated with a file in the svc_rqst 786 * so that they can be passed to the netowork sendmsg/sendpage routines 787 * directrly. They will be released after the sending has completed. 788 */ 789 static int 790 nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size) 791 { 792 unsigned long count = desc->count; 793 struct svc_rqst *rqstp = desc->arg.data; 794 795 if (size > count) 796 size = count; 797 798 if (rqstp->rq_res.page_len == 0) { 799 get_page(page); 800 rqstp->rq_respages[rqstp->rq_resused++] = page; 801 rqstp->rq_res.page_base = offset; 802 rqstp->rq_res.page_len = size; 803 } else if (page != rqstp->rq_respages[rqstp->rq_resused-1]) { 804 get_page(page); 805 rqstp->rq_respages[rqstp->rq_resused++] = page; 806 rqstp->rq_res.page_len += size; 807 } else { 808 rqstp->rq_res.page_len += size; 809 } 810 811 desc->count = count - size; 812 desc->written += size; 813 return size; 814 } 815 816 static int 817 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 818 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 819 { 820 struct inode *inode; 821 struct raparms *ra; 822 mm_segment_t oldfs; 823 int err; 824 825 err = nfserr_perm; 826 inode = file->f_dentry->d_inode; 827 #ifdef MSNFS 828 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 829 (!lock_may_read(inode, offset, *count))) 830 goto out; 831 #endif 832 833 /* Get readahead parameters */ 834 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 835 836 if (ra && ra->p_set) 837 file->f_ra = ra->p_ra; 838 839 if (file->f_op->sendfile && rqstp->rq_sendfile_ok) { 840 svc_pushback_unused_pages(rqstp); 841 err = file->f_op->sendfile(file, &offset, *count, 842 nfsd_read_actor, rqstp); 843 } else { 844 oldfs = get_fs(); 845 set_fs(KERNEL_DS); 846 err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 847 set_fs(oldfs); 848 } 849 850 /* Write back readahead params */ 851 if (ra) { 852 spin_lock(&ra_lock); 853 ra->p_ra = file->f_ra; 854 ra->p_set = 1; 855 ra->p_count--; 856 spin_unlock(&ra_lock); 857 } 858 859 if (err >= 0) { 860 nfsdstats.io_read += err; 861 *count = err; 862 err = 0; 863 fsnotify_access(file->f_dentry); 864 } else 865 err = nfserrno(err); 866 out: 867 return err; 868 } 869 870 static void kill_suid(struct dentry *dentry) 871 { 872 struct iattr ia; 873 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID; 874 875 mutex_lock(&dentry->d_inode->i_mutex); 876 notify_change(dentry, &ia); 877 mutex_unlock(&dentry->d_inode->i_mutex); 878 } 879 880 static int 881 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 882 loff_t offset, struct kvec *vec, int vlen, 883 unsigned long cnt, int *stablep) 884 { 885 struct svc_export *exp; 886 struct dentry *dentry; 887 struct inode *inode; 888 mm_segment_t oldfs; 889 int err = 0; 890 int stable = *stablep; 891 892 #ifdef MSNFS 893 err = nfserr_perm; 894 895 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 896 (!lock_may_write(file->f_dentry->d_inode, offset, cnt))) 897 goto out; 898 #endif 899 900 dentry = file->f_dentry; 901 inode = dentry->d_inode; 902 exp = fhp->fh_export; 903 904 /* 905 * Request sync writes if 906 * - the sync export option has been set, or 907 * - the client requested O_SYNC behavior (NFSv3 feature). 908 * - The file system doesn't support fsync(). 909 * When gathered writes have been configured for this volume, 910 * flushing the data to disk is handled separately below. 911 */ 912 913 if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */ 914 stable = 2; 915 *stablep = 2; /* FILE_SYNC */ 916 } 917 918 if (!EX_ISSYNC(exp)) 919 stable = 0; 920 if (stable && !EX_WGATHER(exp)) 921 file->f_flags |= O_SYNC; 922 923 /* Write the data. */ 924 oldfs = get_fs(); set_fs(KERNEL_DS); 925 err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 926 set_fs(oldfs); 927 if (err >= 0) { 928 nfsdstats.io_write += cnt; 929 fsnotify_modify(file->f_dentry); 930 } 931 932 /* clear setuid/setgid flag after write */ 933 if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) 934 kill_suid(dentry); 935 936 if (err >= 0 && stable) { 937 static ino_t last_ino; 938 static dev_t last_dev; 939 940 /* 941 * Gathered writes: If another process is currently 942 * writing to the file, there's a high chance 943 * this is another nfsd (triggered by a bulk write 944 * from a client's biod). Rather than syncing the 945 * file with each write request, we sleep for 10 msec. 946 * 947 * I don't know if this roughly approximates 948 * C. Juszak's idea of gathered writes, but it's a 949 * nice and simple solution (IMHO), and it seems to 950 * work:-) 951 */ 952 if (EX_WGATHER(exp)) { 953 if (atomic_read(&inode->i_writecount) > 1 954 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 955 dprintk("nfsd: write defer %d\n", current->pid); 956 msleep(10); 957 dprintk("nfsd: write resume %d\n", current->pid); 958 } 959 960 if (inode->i_state & I_DIRTY) { 961 dprintk("nfsd: write sync %d\n", current->pid); 962 err=nfsd_sync(file); 963 } 964 #if 0 965 wake_up(&inode->i_wait); 966 #endif 967 } 968 last_ino = inode->i_ino; 969 last_dev = inode->i_sb->s_dev; 970 } 971 972 dprintk("nfsd: write complete err=%d\n", err); 973 if (err >= 0) 974 err = 0; 975 else 976 err = nfserrno(err); 977 out: 978 return err; 979 } 980 981 /* 982 * Read data from a file. count must contain the requested read count 983 * on entry. On return, *count contains the number of bytes actually read. 984 * N.B. After this call fhp needs an fh_put 985 */ 986 int 987 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 988 loff_t offset, struct kvec *vec, int vlen, 989 unsigned long *count) 990 { 991 int err; 992 993 if (file) { 994 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 995 MAY_READ|MAY_OWNER_OVERRIDE); 996 if (err) 997 goto out; 998 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 999 } else { 1000 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); 1001 if (err) 1002 goto out; 1003 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1004 nfsd_close(file); 1005 } 1006 out: 1007 return err; 1008 } 1009 1010 /* 1011 * Write data to a file. 1012 * The stable flag requests synchronous writes. 1013 * N.B. After this call fhp needs an fh_put 1014 */ 1015 int 1016 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1017 loff_t offset, struct kvec *vec, int vlen, unsigned long cnt, 1018 int *stablep) 1019 { 1020 int err = 0; 1021 1022 if (file) { 1023 err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, 1024 MAY_WRITE|MAY_OWNER_OVERRIDE); 1025 if (err) 1026 goto out; 1027 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1028 stablep); 1029 } else { 1030 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file); 1031 if (err) 1032 goto out; 1033 1034 if (cnt) 1035 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1036 cnt, stablep); 1037 nfsd_close(file); 1038 } 1039 out: 1040 return err; 1041 } 1042 1043 #ifdef CONFIG_NFSD_V3 1044 /* 1045 * Commit all pending writes to stable storage. 1046 * Strictly speaking, we could sync just the indicated file region here, 1047 * but there's currently no way we can ask the VFS to do so. 1048 * 1049 * Unfortunately we cannot lock the file to make sure we return full WCC 1050 * data to the client, as locking happens lower down in the filesystem. 1051 */ 1052 int 1053 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1054 loff_t offset, unsigned long count) 1055 { 1056 struct file *file; 1057 int err; 1058 1059 if ((u64)count > ~(u64)offset) 1060 return nfserr_inval; 1061 1062 if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0) 1063 return err; 1064 if (EX_ISSYNC(fhp->fh_export)) { 1065 if (file->f_op && file->f_op->fsync) { 1066 err = nfserrno(nfsd_sync(file)); 1067 } else { 1068 err = nfserr_notsupp; 1069 } 1070 } 1071 1072 nfsd_close(file); 1073 return err; 1074 } 1075 #endif /* CONFIG_NFSD_V3 */ 1076 1077 /* 1078 * Create a file (regular, directory, device, fifo); UNIX sockets 1079 * not yet implemented. 1080 * If the response fh has been verified, the parent directory should 1081 * already be locked. Note that the parent directory is left locked. 1082 * 1083 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1084 */ 1085 int 1086 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1087 char *fname, int flen, struct iattr *iap, 1088 int type, dev_t rdev, struct svc_fh *resfhp) 1089 { 1090 struct dentry *dentry, *dchild = NULL; 1091 struct inode *dirp; 1092 int err; 1093 1094 err = nfserr_perm; 1095 if (!flen) 1096 goto out; 1097 err = nfserr_exist; 1098 if (isdotent(fname, flen)) 1099 goto out; 1100 1101 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1102 if (err) 1103 goto out; 1104 1105 dentry = fhp->fh_dentry; 1106 dirp = dentry->d_inode; 1107 1108 err = nfserr_notdir; 1109 if(!dirp->i_op || !dirp->i_op->lookup) 1110 goto out; 1111 /* 1112 * Check whether the response file handle has been verified yet. 1113 * If it has, the parent directory should already be locked. 1114 */ 1115 if (!resfhp->fh_dentry) { 1116 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1117 fh_lock(fhp); 1118 dchild = lookup_one_len(fname, dentry, flen); 1119 err = PTR_ERR(dchild); 1120 if (IS_ERR(dchild)) 1121 goto out_nfserr; 1122 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1123 if (err) 1124 goto out; 1125 } else { 1126 /* called from nfsd_proc_create */ 1127 dchild = dget(resfhp->fh_dentry); 1128 if (!fhp->fh_locked) { 1129 /* not actually possible */ 1130 printk(KERN_ERR 1131 "nfsd_create: parent %s/%s not locked!\n", 1132 dentry->d_parent->d_name.name, 1133 dentry->d_name.name); 1134 err = nfserr_io; 1135 goto out; 1136 } 1137 } 1138 /* 1139 * Make sure the child dentry is still negative ... 1140 */ 1141 err = nfserr_exist; 1142 if (dchild->d_inode) { 1143 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1144 dentry->d_name.name, dchild->d_name.name); 1145 goto out; 1146 } 1147 1148 if (!(iap->ia_valid & ATTR_MODE)) 1149 iap->ia_mode = 0; 1150 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1151 1152 /* 1153 * Get the dir op function pointer. 1154 */ 1155 err = nfserr_perm; 1156 switch (type) { 1157 case S_IFREG: 1158 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1159 break; 1160 case S_IFDIR: 1161 err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1162 break; 1163 case S_IFCHR: 1164 case S_IFBLK: 1165 case S_IFIFO: 1166 case S_IFSOCK: 1167 err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1168 break; 1169 default: 1170 printk("nfsd: bad file type %o in nfsd_create\n", type); 1171 err = -EINVAL; 1172 } 1173 if (err < 0) 1174 goto out_nfserr; 1175 1176 if (EX_ISSYNC(fhp->fh_export)) { 1177 err = nfserrno(nfsd_sync_dir(dentry)); 1178 write_inode_now(dchild->d_inode, 1); 1179 } 1180 1181 1182 /* Set file attributes. Mode has already been set and 1183 * setting uid/gid works only for root. Irix appears to 1184 * send along the gid when it tries to implement setgid 1185 * directories via NFS. 1186 */ 1187 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) { 1188 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1189 if (err2) 1190 err = err2; 1191 } 1192 /* 1193 * Update the file handle to get the new inode info. 1194 */ 1195 if (!err) 1196 err = fh_update(resfhp); 1197 out: 1198 if (dchild && !IS_ERR(dchild)) 1199 dput(dchild); 1200 return err; 1201 1202 out_nfserr: 1203 err = nfserrno(err); 1204 goto out; 1205 } 1206 1207 #ifdef CONFIG_NFSD_V3 1208 /* 1209 * NFSv3 version of nfsd_create 1210 */ 1211 int 1212 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1213 char *fname, int flen, struct iattr *iap, 1214 struct svc_fh *resfhp, int createmode, u32 *verifier, 1215 int *truncp) 1216 { 1217 struct dentry *dentry, *dchild = NULL; 1218 struct inode *dirp; 1219 int err; 1220 __u32 v_mtime=0, v_atime=0; 1221 int v_mode=0; 1222 1223 err = nfserr_perm; 1224 if (!flen) 1225 goto out; 1226 err = nfserr_exist; 1227 if (isdotent(fname, flen)) 1228 goto out; 1229 if (!(iap->ia_valid & ATTR_MODE)) 1230 iap->ia_mode = 0; 1231 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1232 if (err) 1233 goto out; 1234 1235 dentry = fhp->fh_dentry; 1236 dirp = dentry->d_inode; 1237 1238 /* Get all the sanity checks out of the way before 1239 * we lock the parent. */ 1240 err = nfserr_notdir; 1241 if(!dirp->i_op || !dirp->i_op->lookup) 1242 goto out; 1243 fh_lock(fhp); 1244 1245 /* 1246 * Compose the response file handle. 1247 */ 1248 dchild = lookup_one_len(fname, dentry, flen); 1249 err = PTR_ERR(dchild); 1250 if (IS_ERR(dchild)) 1251 goto out_nfserr; 1252 1253 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1254 if (err) 1255 goto out; 1256 1257 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1258 /* while the verifier would fit in mtime+atime, 1259 * solaris7 gets confused (bugid 4218508) if these have 1260 * the high bit set, so we use the mode as well 1261 */ 1262 v_mtime = verifier[0]&0x7fffffff; 1263 v_atime = verifier[1]&0x7fffffff; 1264 v_mode = S_IFREG 1265 | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */ 1266 | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */ 1267 ; 1268 } 1269 1270 if (dchild->d_inode) { 1271 err = 0; 1272 1273 switch (createmode) { 1274 case NFS3_CREATE_UNCHECKED: 1275 if (! S_ISREG(dchild->d_inode->i_mode)) 1276 err = nfserr_exist; 1277 else if (truncp) { 1278 /* in nfsv4, we need to treat this case a little 1279 * differently. we don't want to truncate the 1280 * file now; this would be wrong if the OPEN 1281 * fails for some other reason. furthermore, 1282 * if the size is nonzero, we should ignore it 1283 * according to spec! 1284 */ 1285 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1286 } 1287 else { 1288 iap->ia_valid &= ATTR_SIZE; 1289 goto set_attr; 1290 } 1291 break; 1292 case NFS3_CREATE_EXCLUSIVE: 1293 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1294 && dchild->d_inode->i_atime.tv_sec == v_atime 1295 && dchild->d_inode->i_mode == v_mode 1296 && dchild->d_inode->i_size == 0 ) 1297 break; 1298 /* fallthru */ 1299 case NFS3_CREATE_GUARDED: 1300 err = nfserr_exist; 1301 } 1302 goto out; 1303 } 1304 1305 err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1306 if (err < 0) 1307 goto out_nfserr; 1308 1309 if (EX_ISSYNC(fhp->fh_export)) { 1310 err = nfserrno(nfsd_sync_dir(dentry)); 1311 /* setattr will sync the child (or not) */ 1312 } 1313 1314 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1315 /* Cram the verifier into atime/mtime/mode */ 1316 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1317 | ATTR_MTIME_SET|ATTR_ATIME_SET 1318 | ATTR_MODE; 1319 /* XXX someone who knows this better please fix it for nsec */ 1320 iap->ia_mtime.tv_sec = v_mtime; 1321 iap->ia_atime.tv_sec = v_atime; 1322 iap->ia_mtime.tv_nsec = 0; 1323 iap->ia_atime.tv_nsec = 0; 1324 iap->ia_mode = v_mode; 1325 } 1326 1327 /* Set file attributes. 1328 * Mode has already been set but we might need to reset it 1329 * for CREATE_EXCLUSIVE 1330 * Irix appears to send along the gid when it tries to 1331 * implement setgid directories via NFS. Clear out all that cruft. 1332 */ 1333 set_attr: 1334 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0) { 1335 int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1336 if (err2) 1337 err = err2; 1338 } 1339 1340 /* 1341 * Update the filehandle to get the new inode info. 1342 */ 1343 if (!err) 1344 err = fh_update(resfhp); 1345 1346 out: 1347 fh_unlock(fhp); 1348 if (dchild && !IS_ERR(dchild)) 1349 dput(dchild); 1350 return err; 1351 1352 out_nfserr: 1353 err = nfserrno(err); 1354 goto out; 1355 } 1356 #endif /* CONFIG_NFSD_V3 */ 1357 1358 /* 1359 * Read a symlink. On entry, *lenp must contain the maximum path length that 1360 * fits into the buffer. On return, it contains the true length. 1361 * N.B. After this call fhp needs an fh_put 1362 */ 1363 int 1364 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1365 { 1366 struct dentry *dentry; 1367 struct inode *inode; 1368 mm_segment_t oldfs; 1369 int err; 1370 1371 err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP); 1372 if (err) 1373 goto out; 1374 1375 dentry = fhp->fh_dentry; 1376 inode = dentry->d_inode; 1377 1378 err = nfserr_inval; 1379 if (!inode->i_op || !inode->i_op->readlink) 1380 goto out; 1381 1382 touch_atime(fhp->fh_export->ex_mnt, dentry); 1383 /* N.B. Why does this call need a get_fs()?? 1384 * Remove the set_fs and watch the fireworks:-) --okir 1385 */ 1386 1387 oldfs = get_fs(); set_fs(KERNEL_DS); 1388 err = inode->i_op->readlink(dentry, buf, *lenp); 1389 set_fs(oldfs); 1390 1391 if (err < 0) 1392 goto out_nfserr; 1393 *lenp = err; 1394 err = 0; 1395 out: 1396 return err; 1397 1398 out_nfserr: 1399 err = nfserrno(err); 1400 goto out; 1401 } 1402 1403 /* 1404 * Create a symlink and look up its inode 1405 * N.B. After this call _both_ fhp and resfhp need an fh_put 1406 */ 1407 int 1408 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1409 char *fname, int flen, 1410 char *path, int plen, 1411 struct svc_fh *resfhp, 1412 struct iattr *iap) 1413 { 1414 struct dentry *dentry, *dnew; 1415 int err, cerr; 1416 umode_t mode; 1417 1418 err = nfserr_noent; 1419 if (!flen || !plen) 1420 goto out; 1421 err = nfserr_exist; 1422 if (isdotent(fname, flen)) 1423 goto out; 1424 1425 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); 1426 if (err) 1427 goto out; 1428 fh_lock(fhp); 1429 dentry = fhp->fh_dentry; 1430 dnew = lookup_one_len(fname, dentry, flen); 1431 err = PTR_ERR(dnew); 1432 if (IS_ERR(dnew)) 1433 goto out_nfserr; 1434 1435 mode = S_IALLUGO; 1436 /* Only the MODE ATTRibute is even vaguely meaningful */ 1437 if (iap && (iap->ia_valid & ATTR_MODE)) 1438 mode = iap->ia_mode & S_IALLUGO; 1439 1440 if (unlikely(path[plen] != 0)) { 1441 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1442 if (path_alloced == NULL) 1443 err = -ENOMEM; 1444 else { 1445 strncpy(path_alloced, path, plen); 1446 path_alloced[plen] = 0; 1447 err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode); 1448 kfree(path_alloced); 1449 } 1450 } else 1451 err = vfs_symlink(dentry->d_inode, dnew, path, mode); 1452 1453 if (!err) 1454 if (EX_ISSYNC(fhp->fh_export)) 1455 err = nfsd_sync_dir(dentry); 1456 if (err) 1457 err = nfserrno(err); 1458 fh_unlock(fhp); 1459 1460 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1461 dput(dnew); 1462 if (err==0) err = cerr; 1463 out: 1464 return err; 1465 1466 out_nfserr: 1467 err = nfserrno(err); 1468 goto out; 1469 } 1470 1471 /* 1472 * Create a hardlink 1473 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1474 */ 1475 int 1476 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1477 char *name, int len, struct svc_fh *tfhp) 1478 { 1479 struct dentry *ddir, *dnew, *dold; 1480 struct inode *dirp, *dest; 1481 int err; 1482 1483 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE); 1484 if (err) 1485 goto out; 1486 err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP); 1487 if (err) 1488 goto out; 1489 1490 err = nfserr_perm; 1491 if (!len) 1492 goto out; 1493 err = nfserr_exist; 1494 if (isdotent(name, len)) 1495 goto out; 1496 1497 fh_lock(ffhp); 1498 ddir = ffhp->fh_dentry; 1499 dirp = ddir->d_inode; 1500 1501 dnew = lookup_one_len(name, ddir, len); 1502 err = PTR_ERR(dnew); 1503 if (IS_ERR(dnew)) 1504 goto out_nfserr; 1505 1506 dold = tfhp->fh_dentry; 1507 dest = dold->d_inode; 1508 1509 err = vfs_link(dold, dirp, dnew); 1510 if (!err) { 1511 if (EX_ISSYNC(ffhp->fh_export)) { 1512 err = nfserrno(nfsd_sync_dir(ddir)); 1513 write_inode_now(dest, 1); 1514 } 1515 } else { 1516 if (err == -EXDEV && rqstp->rq_vers == 2) 1517 err = nfserr_acces; 1518 else 1519 err = nfserrno(err); 1520 } 1521 1522 dput(dnew); 1523 out_unlock: 1524 fh_unlock(ffhp); 1525 out: 1526 return err; 1527 1528 out_nfserr: 1529 err = nfserrno(err); 1530 goto out_unlock; 1531 } 1532 1533 /* 1534 * Rename a file 1535 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1536 */ 1537 int 1538 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1539 struct svc_fh *tfhp, char *tname, int tlen) 1540 { 1541 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1542 struct inode *fdir, *tdir; 1543 int err; 1544 1545 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE); 1546 if (err) 1547 goto out; 1548 err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE); 1549 if (err) 1550 goto out; 1551 1552 fdentry = ffhp->fh_dentry; 1553 fdir = fdentry->d_inode; 1554 1555 tdentry = tfhp->fh_dentry; 1556 tdir = tdentry->d_inode; 1557 1558 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1559 if (ffhp->fh_export != tfhp->fh_export) 1560 goto out; 1561 1562 err = nfserr_perm; 1563 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1564 goto out; 1565 1566 /* cannot use fh_lock as we need deadlock protective ordering 1567 * so do it by hand */ 1568 trap = lock_rename(tdentry, fdentry); 1569 ffhp->fh_locked = tfhp->fh_locked = 1; 1570 fill_pre_wcc(ffhp); 1571 fill_pre_wcc(tfhp); 1572 1573 odentry = lookup_one_len(fname, fdentry, flen); 1574 err = PTR_ERR(odentry); 1575 if (IS_ERR(odentry)) 1576 goto out_nfserr; 1577 1578 err = -ENOENT; 1579 if (!odentry->d_inode) 1580 goto out_dput_old; 1581 err = -EINVAL; 1582 if (odentry == trap) 1583 goto out_dput_old; 1584 1585 ndentry = lookup_one_len(tname, tdentry, tlen); 1586 err = PTR_ERR(ndentry); 1587 if (IS_ERR(ndentry)) 1588 goto out_dput_old; 1589 err = -ENOTEMPTY; 1590 if (ndentry == trap) 1591 goto out_dput_new; 1592 1593 #ifdef MSNFS 1594 if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1595 ((atomic_read(&odentry->d_count) > 1) 1596 || (atomic_read(&ndentry->d_count) > 1))) { 1597 err = -EPERM; 1598 } else 1599 #endif 1600 err = vfs_rename(fdir, odentry, tdir, ndentry); 1601 if (!err && EX_ISSYNC(tfhp->fh_export)) { 1602 err = nfsd_sync_dir(tdentry); 1603 if (!err) 1604 err = nfsd_sync_dir(fdentry); 1605 } 1606 1607 out_dput_new: 1608 dput(ndentry); 1609 out_dput_old: 1610 dput(odentry); 1611 out_nfserr: 1612 if (err) 1613 err = nfserrno(err); 1614 1615 /* we cannot reply on fh_unlock on the two filehandles, 1616 * as that would do the wrong thing if the two directories 1617 * were the same, so again we do it by hand 1618 */ 1619 fill_post_wcc(ffhp); 1620 fill_post_wcc(tfhp); 1621 unlock_rename(tdentry, fdentry); 1622 ffhp->fh_locked = tfhp->fh_locked = 0; 1623 1624 out: 1625 return err; 1626 } 1627 1628 /* 1629 * Unlink a file or directory 1630 * N.B. After this call fhp needs an fh_put 1631 */ 1632 int 1633 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1634 char *fname, int flen) 1635 { 1636 struct dentry *dentry, *rdentry; 1637 struct inode *dirp; 1638 int err; 1639 1640 err = nfserr_acces; 1641 if (!flen || isdotent(fname, flen)) 1642 goto out; 1643 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE); 1644 if (err) 1645 goto out; 1646 1647 fh_lock(fhp); 1648 dentry = fhp->fh_dentry; 1649 dirp = dentry->d_inode; 1650 1651 rdentry = lookup_one_len(fname, dentry, flen); 1652 err = PTR_ERR(rdentry); 1653 if (IS_ERR(rdentry)) 1654 goto out_nfserr; 1655 1656 if (!rdentry->d_inode) { 1657 dput(rdentry); 1658 err = nfserr_noent; 1659 goto out; 1660 } 1661 1662 if (!type) 1663 type = rdentry->d_inode->i_mode & S_IFMT; 1664 1665 if (type != S_IFDIR) { /* It's UNLINK */ 1666 #ifdef MSNFS 1667 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1668 (atomic_read(&rdentry->d_count) > 1)) { 1669 err = -EPERM; 1670 } else 1671 #endif 1672 err = vfs_unlink(dirp, rdentry); 1673 } else { /* It's RMDIR */ 1674 err = vfs_rmdir(dirp, rdentry); 1675 } 1676 1677 dput(rdentry); 1678 1679 if (err == 0 && 1680 EX_ISSYNC(fhp->fh_export)) 1681 err = nfsd_sync_dir(dentry); 1682 1683 out_nfserr: 1684 err = nfserrno(err); 1685 out: 1686 return err; 1687 } 1688 1689 /* 1690 * Read entries from a directory. 1691 * The NFSv3/4 verifier we ignore for now. 1692 */ 1693 int 1694 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1695 struct readdir_cd *cdp, encode_dent_fn func) 1696 { 1697 int err; 1698 struct file *file; 1699 loff_t offset = *offsetp; 1700 1701 err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); 1702 if (err) 1703 goto out; 1704 1705 offset = vfs_llseek(file, offset, 0); 1706 if (offset < 0) { 1707 err = nfserrno((int)offset); 1708 goto out_close; 1709 } 1710 1711 /* 1712 * Read the directory entries. This silly loop is necessary because 1713 * readdir() is not guaranteed to fill up the entire buffer, but 1714 * may choose to do less. 1715 */ 1716 1717 do { 1718 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1719 err = vfs_readdir(file, (filldir_t) func, cdp); 1720 } while (err >=0 && cdp->err == nfs_ok); 1721 if (err) 1722 err = nfserrno(err); 1723 else 1724 err = cdp->err; 1725 *offsetp = vfs_llseek(file, 0, 1); 1726 1727 if (err == nfserr_eof || err == nfserr_toosmall) 1728 err = nfs_ok; /* can still be found in ->err */ 1729 out_close: 1730 nfsd_close(file); 1731 out: 1732 return err; 1733 } 1734 1735 /* 1736 * Get file system stats 1737 * N.B. After this call fhp needs an fh_put 1738 */ 1739 int 1740 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat) 1741 { 1742 int err = fh_verify(rqstp, fhp, 0, MAY_NOP); 1743 if (!err && vfs_statfs(fhp->fh_dentry,stat)) 1744 err = nfserr_io; 1745 return err; 1746 } 1747 1748 /* 1749 * Check for a user's access permissions to this inode. 1750 */ 1751 int 1752 nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc) 1753 { 1754 struct inode *inode = dentry->d_inode; 1755 int err; 1756 1757 if (acc == MAY_NOP) 1758 return 0; 1759 #if 0 1760 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 1761 acc, 1762 (acc & MAY_READ)? " read" : "", 1763 (acc & MAY_WRITE)? " write" : "", 1764 (acc & MAY_EXEC)? " exec" : "", 1765 (acc & MAY_SATTR)? " sattr" : "", 1766 (acc & MAY_TRUNC)? " trunc" : "", 1767 (acc & MAY_LOCK)? " lock" : "", 1768 (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "", 1769 inode->i_mode, 1770 IS_IMMUTABLE(inode)? " immut" : "", 1771 IS_APPEND(inode)? " append" : "", 1772 IS_RDONLY(inode)? " ro" : ""); 1773 dprintk(" owner %d/%d user %d/%d\n", 1774 inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); 1775 #endif 1776 1777 /* Normally we reject any write/sattr etc access on a read-only file 1778 * system. But if it is IRIX doing check on write-access for a 1779 * device special file, we ignore rofs. 1780 */ 1781 if (!(acc & MAY_LOCAL_ACCESS)) 1782 if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { 1783 if (EX_RDONLY(exp) || IS_RDONLY(inode)) 1784 return nfserr_rofs; 1785 if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) 1786 return nfserr_perm; 1787 } 1788 if ((acc & MAY_TRUNC) && IS_APPEND(inode)) 1789 return nfserr_perm; 1790 1791 if (acc & MAY_LOCK) { 1792 /* If we cannot rely on authentication in NLM requests, 1793 * just allow locks, otherwise require read permission, or 1794 * ownership 1795 */ 1796 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 1797 return 0; 1798 else 1799 acc = MAY_READ | MAY_OWNER_OVERRIDE; 1800 } 1801 /* 1802 * The file owner always gets access permission for accesses that 1803 * would normally be checked at open time. This is to make 1804 * file access work even when the client has done a fchmod(fd, 0). 1805 * 1806 * However, `cp foo bar' should fail nevertheless when bar is 1807 * readonly. A sensible way to do this might be to reject all 1808 * attempts to truncate a read-only file, because a creat() call 1809 * always implies file truncation. 1810 * ... but this isn't really fair. A process may reasonably call 1811 * ftruncate on an open file descriptor on a file with perm 000. 1812 * We must trust the client to do permission checking - using "ACCESS" 1813 * with NFSv3. 1814 */ 1815 if ((acc & MAY_OWNER_OVERRIDE) && 1816 inode->i_uid == current->fsuid) 1817 return 0; 1818 1819 err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL); 1820 1821 /* Allow read access to binaries even when mode 111 */ 1822 if (err == -EACCES && S_ISREG(inode->i_mode) && 1823 acc == (MAY_READ | MAY_OWNER_OVERRIDE)) 1824 err = permission(inode, MAY_EXEC, NULL); 1825 1826 return err? nfserrno(err) : 0; 1827 } 1828 1829 void 1830 nfsd_racache_shutdown(void) 1831 { 1832 if (!raparm_cache) 1833 return; 1834 dprintk("nfsd: freeing readahead buffers.\n"); 1835 kfree(raparml); 1836 raparm_cache = raparml = NULL; 1837 } 1838 /* 1839 * Initialize readahead param cache 1840 */ 1841 int 1842 nfsd_racache_init(int cache_size) 1843 { 1844 int i; 1845 1846 if (raparm_cache) 1847 return 0; 1848 raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); 1849 1850 if (raparml != NULL) { 1851 dprintk("nfsd: allocating %d readahead buffers.\n", 1852 cache_size); 1853 memset(raparml, 0, sizeof(struct raparms) * cache_size); 1854 for (i = 0; i < cache_size - 1; i++) { 1855 raparml[i].p_next = raparml + i + 1; 1856 } 1857 raparm_cache = raparml; 1858 } else { 1859 printk(KERN_WARNING 1860 "nfsd: Could not allocate memory read-ahead cache.\n"); 1861 return -ENOMEM; 1862 } 1863 nfsdstats.ra_size = cache_size; 1864 return 0; 1865 } 1866 1867 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 1868 struct posix_acl * 1869 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 1870 { 1871 struct inode *inode = fhp->fh_dentry->d_inode; 1872 char *name; 1873 void *value = NULL; 1874 ssize_t size; 1875 struct posix_acl *acl; 1876 1877 if (!IS_POSIXACL(inode)) 1878 return ERR_PTR(-EOPNOTSUPP); 1879 1880 switch (type) { 1881 case ACL_TYPE_ACCESS: 1882 name = POSIX_ACL_XATTR_ACCESS; 1883 break; 1884 case ACL_TYPE_DEFAULT: 1885 name = POSIX_ACL_XATTR_DEFAULT; 1886 break; 1887 default: 1888 return ERR_PTR(-EOPNOTSUPP); 1889 } 1890 1891 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 1892 if (size < 0) 1893 return ERR_PTR(size); 1894 1895 acl = posix_acl_from_xattr(value, size); 1896 kfree(value); 1897 return acl; 1898 } 1899 1900 int 1901 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 1902 { 1903 struct inode *inode = fhp->fh_dentry->d_inode; 1904 char *name; 1905 void *value = NULL; 1906 size_t size; 1907 int error; 1908 1909 if (!IS_POSIXACL(inode) || !inode->i_op || 1910 !inode->i_op->setxattr || !inode->i_op->removexattr) 1911 return -EOPNOTSUPP; 1912 switch(type) { 1913 case ACL_TYPE_ACCESS: 1914 name = POSIX_ACL_XATTR_ACCESS; 1915 break; 1916 case ACL_TYPE_DEFAULT: 1917 name = POSIX_ACL_XATTR_DEFAULT; 1918 break; 1919 default: 1920 return -EOPNOTSUPP; 1921 } 1922 1923 if (acl && acl->a_count) { 1924 size = posix_acl_xattr_size(acl->a_count); 1925 value = kmalloc(size, GFP_KERNEL); 1926 if (!value) 1927 return -ENOMEM; 1928 error = posix_acl_to_xattr(acl, value, size); 1929 if (error < 0) 1930 goto getout; 1931 size = error; 1932 } else 1933 size = 0; 1934 1935 if (size) 1936 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 1937 else { 1938 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 1939 error = 0; 1940 else { 1941 error = vfs_removexattr(fhp->fh_dentry, name); 1942 if (error == -ENODATA) 1943 error = 0; 1944 } 1945 } 1946 1947 getout: 1948 kfree(value); 1949 return error; 1950 } 1951 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 1952