1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This file contains vfs inode ops for the 9P2000 protocol. 4 * 5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> 6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> 7 */ 8 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/module.h> 12 #include <linux/errno.h> 13 #include <linux/fs.h> 14 #include <linux/file.h> 15 #include <linux/pagemap.h> 16 #include <linux/stat.h> 17 #include <linux/string.h> 18 #include <linux/namei.h> 19 #include <linux/sched.h> 20 #include <linux/slab.h> 21 #include <linux/xattr.h> 22 #include <linux/posix_acl.h> 23 #include <net/9p/9p.h> 24 #include <net/9p/client.h> 25 26 #include "v9fs.h" 27 #include "v9fs_vfs.h" 28 #include "fid.h" 29 #include "cache.h" 30 #include "xattr.h" 31 #include "acl.h" 32 33 static const struct inode_operations v9fs_dir_inode_operations; 34 static const struct inode_operations v9fs_dir_inode_operations_dotu; 35 static const struct inode_operations v9fs_file_inode_operations; 36 static const struct inode_operations v9fs_symlink_inode_operations; 37 38 /** 39 * unixmode2p9mode - convert unix mode bits to plan 9 40 * @v9ses: v9fs session information 41 * @mode: mode to convert 42 * 43 */ 44 45 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode) 46 { 47 int res; 48 49 res = mode & 0777; 50 if (S_ISDIR(mode)) 51 res |= P9_DMDIR; 52 if (v9fs_proto_dotu(v9ses)) { 53 if (v9ses->nodev == 0) { 54 if (S_ISSOCK(mode)) 55 res |= P9_DMSOCKET; 56 if (S_ISFIFO(mode)) 57 res |= P9_DMNAMEDPIPE; 58 if (S_ISBLK(mode)) 59 res |= P9_DMDEVICE; 60 if (S_ISCHR(mode)) 61 res |= P9_DMDEVICE; 62 } 63 64 if ((mode & S_ISUID) == S_ISUID) 65 res |= P9_DMSETUID; 66 if ((mode & S_ISGID) == S_ISGID) 67 res |= P9_DMSETGID; 68 if ((mode & S_ISVTX) == S_ISVTX) 69 res |= P9_DMSETVTX; 70 } 71 return res; 72 } 73 74 /** 75 * p9mode2perm- convert plan9 mode bits to unix permission bits 76 * @v9ses: v9fs session information 77 * @stat: p9_wstat from which mode need to be derived 78 * 79 */ 80 static int p9mode2perm(struct v9fs_session_info *v9ses, 81 struct p9_wstat *stat) 82 { 83 int res; 84 int mode = stat->mode; 85 86 res = mode & 0777; /* S_IRWXUGO */ 87 if (v9fs_proto_dotu(v9ses)) { 88 if ((mode & P9_DMSETUID) == P9_DMSETUID) 89 res |= S_ISUID; 90 91 if ((mode & P9_DMSETGID) == P9_DMSETGID) 92 res |= S_ISGID; 93 94 if ((mode & P9_DMSETVTX) == P9_DMSETVTX) 95 res |= S_ISVTX; 96 } 97 return res; 98 } 99 100 /** 101 * p9mode2unixmode- convert plan9 mode bits to unix mode bits 102 * @v9ses: v9fs session information 103 * @stat: p9_wstat from which mode need to be derived 104 * @rdev: major number, minor number in case of device files. 105 * 106 */ 107 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses, 108 struct p9_wstat *stat, dev_t *rdev) 109 { 110 int res, r; 111 u32 mode = stat->mode; 112 113 *rdev = 0; 114 res = p9mode2perm(v9ses, stat); 115 116 if ((mode & P9_DMDIR) == P9_DMDIR) 117 res |= S_IFDIR; 118 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses))) 119 res |= S_IFLNK; 120 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses)) 121 && (v9ses->nodev == 0)) 122 res |= S_IFSOCK; 123 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses)) 124 && (v9ses->nodev == 0)) 125 res |= S_IFIFO; 126 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses)) 127 && (v9ses->nodev == 0)) { 128 char type = 0; 129 int major = -1, minor = -1; 130 131 r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor); 132 if (r != 3) { 133 p9_debug(P9_DEBUG_ERROR, 134 "invalid device string, umode will be bogus: %s\n", 135 stat->extension); 136 return res; 137 } 138 switch (type) { 139 case 'c': 140 res |= S_IFCHR; 141 break; 142 case 'b': 143 res |= S_IFBLK; 144 break; 145 default: 146 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n", 147 type, stat->extension); 148 } 149 *rdev = MKDEV(major, minor); 150 } else 151 res |= S_IFREG; 152 153 return res; 154 } 155 156 /** 157 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits 158 * @uflags: flags to convert 159 * @extended: if .u extensions are active 160 */ 161 162 int v9fs_uflags2omode(int uflags, int extended) 163 { 164 int ret; 165 166 switch (uflags&3) { 167 default: 168 case O_RDONLY: 169 ret = P9_OREAD; 170 break; 171 172 case O_WRONLY: 173 ret = P9_OWRITE; 174 break; 175 176 case O_RDWR: 177 ret = P9_ORDWR; 178 break; 179 } 180 181 if (uflags & O_TRUNC) 182 ret |= P9_OTRUNC; 183 184 if (extended) { 185 if (uflags & O_EXCL) 186 ret |= P9_OEXCL; 187 188 if (uflags & O_APPEND) 189 ret |= P9_OAPPEND; 190 } 191 192 return ret; 193 } 194 195 /** 196 * v9fs_blank_wstat - helper function to setup a 9P stat structure 197 * @wstat: structure to initialize 198 * 199 */ 200 201 void 202 v9fs_blank_wstat(struct p9_wstat *wstat) 203 { 204 wstat->type = ~0; 205 wstat->dev = ~0; 206 wstat->qid.type = ~0; 207 wstat->qid.version = ~0; 208 *((long long *)&wstat->qid.path) = ~0; 209 wstat->mode = ~0; 210 wstat->atime = ~0; 211 wstat->mtime = ~0; 212 wstat->length = ~0; 213 wstat->name = NULL; 214 wstat->uid = NULL; 215 wstat->gid = NULL; 216 wstat->muid = NULL; 217 wstat->n_uid = INVALID_UID; 218 wstat->n_gid = INVALID_GID; 219 wstat->n_muid = INVALID_UID; 220 wstat->extension = NULL; 221 } 222 223 /** 224 * v9fs_alloc_inode - helper function to allocate an inode 225 * @sb: The superblock to allocate the inode from 226 */ 227 struct inode *v9fs_alloc_inode(struct super_block *sb) 228 { 229 struct v9fs_inode *v9inode; 230 231 v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL); 232 if (!v9inode) 233 return NULL; 234 v9inode->cache_validity = 0; 235 mutex_init(&v9inode->v_mutex); 236 return &v9inode->netfs.inode; 237 } 238 239 /** 240 * v9fs_free_inode - destroy an inode 241 * @inode: The inode to be freed 242 */ 243 244 void v9fs_free_inode(struct inode *inode) 245 { 246 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode)); 247 } 248 249 /* 250 * Set parameters for the netfs library 251 */ 252 void v9fs_set_netfs_context(struct inode *inode) 253 { 254 struct v9fs_inode *v9inode = V9FS_I(inode); 255 netfs_inode_init(&v9inode->netfs, &v9fs_req_ops, true); 256 } 257 258 int v9fs_init_inode(struct v9fs_session_info *v9ses, 259 struct inode *inode, struct p9_qid *qid, umode_t mode, dev_t rdev) 260 { 261 int err = 0; 262 struct v9fs_inode *v9inode = V9FS_I(inode); 263 264 memcpy(&v9inode->qid, qid, sizeof(struct p9_qid)); 265 266 inode_init_owner(&nop_mnt_idmap, inode, NULL, mode); 267 inode->i_blocks = 0; 268 inode->i_rdev = rdev; 269 simple_inode_init_ts(inode); 270 inode->i_mapping->a_ops = &v9fs_addr_operations; 271 inode->i_private = NULL; 272 273 switch (mode & S_IFMT) { 274 case S_IFIFO: 275 case S_IFBLK: 276 case S_IFCHR: 277 case S_IFSOCK: 278 if (v9fs_proto_dotl(v9ses)) { 279 inode->i_op = &v9fs_file_inode_operations_dotl; 280 } else if (v9fs_proto_dotu(v9ses)) { 281 inode->i_op = &v9fs_file_inode_operations; 282 } else { 283 p9_debug(P9_DEBUG_ERROR, 284 "special files without extended mode\n"); 285 err = -EINVAL; 286 goto error; 287 } 288 init_special_inode(inode, inode->i_mode, inode->i_rdev); 289 break; 290 case S_IFREG: 291 if (v9fs_proto_dotl(v9ses)) { 292 inode->i_op = &v9fs_file_inode_operations_dotl; 293 inode->i_fop = &v9fs_file_operations_dotl; 294 } else { 295 inode->i_op = &v9fs_file_inode_operations; 296 inode->i_fop = &v9fs_file_operations; 297 } 298 299 break; 300 case S_IFLNK: 301 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) { 302 p9_debug(P9_DEBUG_ERROR, 303 "extended modes used with legacy protocol\n"); 304 err = -EINVAL; 305 goto error; 306 } 307 308 if (v9fs_proto_dotl(v9ses)) 309 inode->i_op = &v9fs_symlink_inode_operations_dotl; 310 else 311 inode->i_op = &v9fs_symlink_inode_operations; 312 313 break; 314 case S_IFDIR: 315 inc_nlink(inode); 316 if (v9fs_proto_dotl(v9ses)) 317 inode->i_op = &v9fs_dir_inode_operations_dotl; 318 else if (v9fs_proto_dotu(v9ses)) 319 inode->i_op = &v9fs_dir_inode_operations_dotu; 320 else 321 inode->i_op = &v9fs_dir_inode_operations; 322 323 if (v9fs_proto_dotl(v9ses)) 324 inode->i_fop = &v9fs_dir_operations_dotl; 325 else 326 inode->i_fop = &v9fs_dir_operations; 327 328 break; 329 default: 330 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n", 331 mode, mode & S_IFMT); 332 err = -EINVAL; 333 goto error; 334 } 335 error: 336 return err; 337 338 } 339 340 /** 341 * v9fs_evict_inode - Remove an inode from the inode cache 342 * @inode: inode to release 343 * 344 */ 345 void v9fs_evict_inode(struct inode *inode) 346 { 347 struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode); 348 __le32 __maybe_unused version; 349 350 if (!is_bad_inode(inode)) { 351 truncate_inode_pages_final(&inode->i_data); 352 353 version = cpu_to_le32(v9inode->qid.version); 354 netfs_clear_inode_writeback(inode, &version); 355 356 clear_inode(inode); 357 filemap_fdatawrite(&inode->i_data); 358 359 #ifdef CONFIG_9P_FSCACHE 360 if (v9fs_inode_cookie(v9inode)) 361 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); 362 #endif 363 } else 364 clear_inode(inode); 365 } 366 367 struct inode * 368 v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid, bool new) 369 { 370 dev_t rdev; 371 int retval; 372 umode_t umode; 373 struct inode *inode; 374 struct p9_wstat *st; 375 struct v9fs_session_info *v9ses = sb->s_fs_info; 376 377 inode = iget_locked(sb, QID2INO(&fid->qid)); 378 if (unlikely(!inode)) 379 return ERR_PTR(-ENOMEM); 380 if (!(inode->i_state & I_NEW)) { 381 if (!new) { 382 goto done; 383 } else { 384 p9_debug(P9_DEBUG_VFS, "WARNING: Inode collision %ld\n", 385 inode->i_ino); 386 iput(inode); 387 remove_inode_hash(inode); 388 inode = iget_locked(sb, QID2INO(&fid->qid)); 389 WARN_ON(!(inode->i_state & I_NEW)); 390 } 391 } 392 393 /* 394 * initialize the inode with the stat info 395 * FIXME!! we may need support for stale inodes 396 * later. 397 */ 398 st = p9_client_stat(fid); 399 if (IS_ERR(st)) { 400 retval = PTR_ERR(st); 401 goto error; 402 } 403 404 umode = p9mode2unixmode(v9ses, st, &rdev); 405 retval = v9fs_init_inode(v9ses, inode, &fid->qid, umode, rdev); 406 v9fs_stat2inode(st, inode, sb, 0); 407 p9stat_free(st); 408 kfree(st); 409 if (retval) 410 goto error; 411 412 v9fs_set_netfs_context(inode); 413 v9fs_cache_inode_get_cookie(inode); 414 unlock_new_inode(inode); 415 done: 416 return inode; 417 error: 418 iget_failed(inode); 419 return ERR_PTR(retval); 420 } 421 422 /** 423 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to 424 * plan 9 AT flag. 425 * @flags: flags to convert 426 */ 427 static int v9fs_at_to_dotl_flags(int flags) 428 { 429 int rflags = 0; 430 431 if (flags & AT_REMOVEDIR) 432 rflags |= P9_DOTL_AT_REMOVEDIR; 433 434 return rflags; 435 } 436 437 /** 438 * v9fs_dec_count - helper functon to drop i_nlink. 439 * 440 * If a directory had nlink <= 2 (including . and ..), then we should not drop 441 * the link count, which indicates the underlying exported fs doesn't maintain 442 * nlink accurately. e.g. 443 * - overlayfs sets nlink to 1 for merged dir 444 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more 445 * than EXT4_LINK_MAX (65000) links. 446 * 447 * @inode: inode whose nlink is being dropped 448 */ 449 static void v9fs_dec_count(struct inode *inode) 450 { 451 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) { 452 if (inode->i_nlink) { 453 drop_nlink(inode); 454 } else { 455 p9_debug(P9_DEBUG_VFS, 456 "WARNING: unexpected i_nlink zero %d inode %ld\n", 457 inode->i_nlink, inode->i_ino); 458 } 459 } 460 } 461 462 /** 463 * v9fs_remove - helper function to remove files and directories 464 * @dir: directory inode that is being deleted 465 * @dentry: dentry that is being deleted 466 * @flags: removing a directory 467 * 468 */ 469 470 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) 471 { 472 struct inode *inode; 473 int retval = -EOPNOTSUPP; 474 struct p9_fid *v9fid, *dfid; 475 struct v9fs_session_info *v9ses; 476 477 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n", 478 dir, dentry, flags); 479 480 v9ses = v9fs_inode2v9ses(dir); 481 inode = d_inode(dentry); 482 dfid = v9fs_parent_fid(dentry); 483 if (IS_ERR(dfid)) { 484 retval = PTR_ERR(dfid); 485 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval); 486 return retval; 487 } 488 if (v9fs_proto_dotl(v9ses)) 489 retval = p9_client_unlinkat(dfid, dentry->d_name.name, 490 v9fs_at_to_dotl_flags(flags)); 491 p9_fid_put(dfid); 492 if (retval == -EOPNOTSUPP) { 493 /* Try the one based on path */ 494 v9fid = v9fs_fid_clone(dentry); 495 if (IS_ERR(v9fid)) 496 return PTR_ERR(v9fid); 497 retval = p9_client_remove(v9fid); 498 } 499 if (!retval) { 500 /* 501 * directories on unlink should have zero 502 * link count 503 */ 504 if (flags & AT_REMOVEDIR) { 505 clear_nlink(inode); 506 v9fs_dec_count(dir); 507 } else 508 v9fs_dec_count(inode); 509 510 if (inode->i_nlink <= 0) /* no more refs unhash it */ 511 remove_inode_hash(inode); 512 513 v9fs_invalidate_inode_attr(inode); 514 v9fs_invalidate_inode_attr(dir); 515 516 /* invalidate all fids associated with dentry */ 517 /* NOTE: This will not include open fids */ 518 dentry->d_op->d_release(dentry); 519 } 520 return retval; 521 } 522 523 /** 524 * v9fs_create - Create a file 525 * @v9ses: session information 526 * @dir: directory that dentry is being created in 527 * @dentry: dentry that is being created 528 * @extension: 9p2000.u extension string to support devices, etc. 529 * @perm: create permissions 530 * @mode: open mode 531 * 532 */ 533 static struct p9_fid * 534 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 535 struct dentry *dentry, char *extension, u32 perm, u8 mode) 536 { 537 int err; 538 const unsigned char *name; 539 struct p9_fid *dfid, *ofid = NULL, *fid = NULL; 540 struct inode *inode; 541 542 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 543 544 name = dentry->d_name.name; 545 dfid = v9fs_parent_fid(dentry); 546 if (IS_ERR(dfid)) { 547 err = PTR_ERR(dfid); 548 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err); 549 return ERR_PTR(err); 550 } 551 552 /* clone a fid to use for creation */ 553 ofid = clone_fid(dfid); 554 if (IS_ERR(ofid)) { 555 err = PTR_ERR(ofid); 556 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); 557 goto error; 558 } 559 560 err = p9_client_fcreate(ofid, name, perm, mode, extension); 561 if (err < 0) { 562 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); 563 goto error; 564 } 565 566 if (!(perm & P9_DMLINK)) { 567 /* now walk from the parent so we can get unopened fid */ 568 fid = p9_client_walk(dfid, 1, &name, 1); 569 if (IS_ERR(fid)) { 570 err = PTR_ERR(fid); 571 p9_debug(P9_DEBUG_VFS, 572 "p9_client_walk failed %d\n", err); 573 goto error; 574 } 575 /* 576 * instantiate inode and assign the unopened fid to the dentry 577 */ 578 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, true); 579 if (IS_ERR(inode)) { 580 err = PTR_ERR(inode); 581 p9_debug(P9_DEBUG_VFS, 582 "inode creation failed %d\n", err); 583 goto error; 584 } 585 v9fs_fid_add(dentry, &fid); 586 d_instantiate(dentry, inode); 587 } 588 p9_fid_put(dfid); 589 return ofid; 590 error: 591 p9_fid_put(dfid); 592 p9_fid_put(ofid); 593 p9_fid_put(fid); 594 return ERR_PTR(err); 595 } 596 597 /** 598 * v9fs_vfs_create - VFS hook to create a regular file 599 * @idmap: idmap of the mount 600 * @dir: The parent directory 601 * @dentry: The name of file to be created 602 * @mode: The UNIX file mode to set 603 * @excl: True if the file must not yet exist 604 * 605 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called 606 * for mknod(2). 607 * 608 */ 609 610 static int 611 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir, 612 struct dentry *dentry, umode_t mode, bool excl) 613 { 614 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 615 u32 perm = unixmode2p9mode(v9ses, mode); 616 struct p9_fid *fid; 617 618 /* P9_OEXCL? */ 619 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR); 620 if (IS_ERR(fid)) 621 return PTR_ERR(fid); 622 623 v9fs_invalidate_inode_attr(dir); 624 p9_fid_put(fid); 625 626 return 0; 627 } 628 629 /** 630 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory 631 * @idmap: idmap of the mount 632 * @dir: inode that is being unlinked 633 * @dentry: dentry that is being unlinked 634 * @mode: mode for new directory 635 * 636 */ 637 638 static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir, 639 struct dentry *dentry, umode_t mode) 640 { 641 int err; 642 u32 perm; 643 struct p9_fid *fid; 644 struct v9fs_session_info *v9ses; 645 646 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 647 err = 0; 648 v9ses = v9fs_inode2v9ses(dir); 649 perm = unixmode2p9mode(v9ses, mode | S_IFDIR); 650 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD); 651 if (IS_ERR(fid)) { 652 err = PTR_ERR(fid); 653 fid = NULL; 654 } else { 655 inc_nlink(dir); 656 v9fs_invalidate_inode_attr(dir); 657 } 658 659 if (fid) 660 p9_fid_put(fid); 661 662 return err; 663 } 664 665 /** 666 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode 667 * @dir: inode that is being walked from 668 * @dentry: dentry that is being walked to? 669 * @flags: lookup flags (unused) 670 * 671 */ 672 673 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, 674 unsigned int flags) 675 { 676 struct dentry *res; 677 struct v9fs_session_info *v9ses; 678 struct p9_fid *dfid, *fid; 679 struct inode *inode; 680 const unsigned char *name; 681 682 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n", 683 dir, dentry, dentry, flags); 684 685 if (dentry->d_name.len > NAME_MAX) 686 return ERR_PTR(-ENAMETOOLONG); 687 688 v9ses = v9fs_inode2v9ses(dir); 689 /* We can walk d_parent because we hold the dir->i_mutex */ 690 dfid = v9fs_parent_fid(dentry); 691 if (IS_ERR(dfid)) 692 return ERR_CAST(dfid); 693 694 /* 695 * Make sure we don't use a wrong inode due to parallel 696 * unlink. For cached mode create calls request for new 697 * inode. But with cache disabled, lookup should do this. 698 */ 699 name = dentry->d_name.name; 700 fid = p9_client_walk(dfid, 1, &name, 1); 701 p9_fid_put(dfid); 702 if (fid == ERR_PTR(-ENOENT)) 703 inode = NULL; 704 else if (IS_ERR(fid)) 705 inode = ERR_CAST(fid); 706 else 707 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, false); 708 /* 709 * If we had a rename on the server and a parallel lookup 710 * for the new name, then make sure we instantiate with 711 * the new name. ie look up for a/b, while on server somebody 712 * moved b under k and client parallely did a lookup for 713 * k/b. 714 */ 715 res = d_splice_alias(inode, dentry); 716 if (!IS_ERR(fid)) { 717 if (!res) 718 v9fs_fid_add(dentry, &fid); 719 else if (!IS_ERR(res)) 720 v9fs_fid_add(res, &fid); 721 else 722 p9_fid_put(fid); 723 } 724 return res; 725 } 726 727 static int 728 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, 729 struct file *file, unsigned int flags, umode_t mode) 730 { 731 int err; 732 u32 perm; 733 struct v9fs_inode __maybe_unused *v9inode; 734 struct v9fs_session_info *v9ses; 735 struct p9_fid *fid; 736 struct dentry *res = NULL; 737 struct inode *inode; 738 int p9_omode; 739 740 if (d_in_lookup(dentry)) { 741 res = v9fs_vfs_lookup(dir, dentry, 0); 742 if (IS_ERR(res)) 743 return PTR_ERR(res); 744 745 if (res) 746 dentry = res; 747 } 748 749 /* Only creates */ 750 if (!(flags & O_CREAT) || d_really_is_positive(dentry)) 751 return finish_no_open(file, res); 752 753 v9ses = v9fs_inode2v9ses(dir); 754 perm = unixmode2p9mode(v9ses, mode); 755 p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses)); 756 757 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) { 758 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR; 759 p9_debug(P9_DEBUG_CACHE, 760 "write-only file with writeback enabled, creating w/ O_RDWR\n"); 761 } 762 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode); 763 if (IS_ERR(fid)) { 764 err = PTR_ERR(fid); 765 goto error; 766 } 767 768 v9fs_invalidate_inode_attr(dir); 769 inode = d_inode(dentry); 770 v9inode = V9FS_I(inode); 771 err = finish_open(file, dentry, generic_file_open); 772 if (err) 773 goto error; 774 775 file->private_data = fid; 776 #ifdef CONFIG_9P_FSCACHE 777 if (v9ses->cache & CACHE_FSCACHE) 778 fscache_use_cookie(v9fs_inode_cookie(v9inode), 779 file->f_mode & FMODE_WRITE); 780 #endif 781 782 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags); 783 v9fs_open_fid_add(inode, &fid); 784 785 file->f_mode |= FMODE_CREATED; 786 out: 787 dput(res); 788 return err; 789 790 error: 791 p9_fid_put(fid); 792 goto out; 793 } 794 795 /** 796 * v9fs_vfs_unlink - VFS unlink hook to delete an inode 797 * @i: inode that is being unlinked 798 * @d: dentry that is being unlinked 799 * 800 */ 801 802 int v9fs_vfs_unlink(struct inode *i, struct dentry *d) 803 { 804 return v9fs_remove(i, d, 0); 805 } 806 807 /** 808 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory 809 * @i: inode that is being unlinked 810 * @d: dentry that is being unlinked 811 * 812 */ 813 814 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d) 815 { 816 return v9fs_remove(i, d, AT_REMOVEDIR); 817 } 818 819 /** 820 * v9fs_vfs_rename - VFS hook to rename an inode 821 * @idmap: The idmap of the mount 822 * @old_dir: old dir inode 823 * @old_dentry: old dentry 824 * @new_dir: new dir inode 825 * @new_dentry: new dentry 826 * @flags: RENAME_* flags 827 * 828 */ 829 830 int 831 v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, 832 struct dentry *old_dentry, struct inode *new_dir, 833 struct dentry *new_dentry, unsigned int flags) 834 { 835 int retval; 836 struct inode *old_inode; 837 struct inode *new_inode; 838 struct v9fs_session_info *v9ses; 839 struct p9_fid *oldfid = NULL, *dfid = NULL; 840 struct p9_fid *olddirfid = NULL; 841 struct p9_fid *newdirfid = NULL; 842 struct p9_wstat wstat; 843 844 if (flags) 845 return -EINVAL; 846 847 p9_debug(P9_DEBUG_VFS, "\n"); 848 old_inode = d_inode(old_dentry); 849 new_inode = d_inode(new_dentry); 850 v9ses = v9fs_inode2v9ses(old_inode); 851 oldfid = v9fs_fid_lookup(old_dentry); 852 if (IS_ERR(oldfid)) 853 return PTR_ERR(oldfid); 854 855 dfid = v9fs_parent_fid(old_dentry); 856 olddirfid = clone_fid(dfid); 857 p9_fid_put(dfid); 858 dfid = NULL; 859 860 if (IS_ERR(olddirfid)) { 861 retval = PTR_ERR(olddirfid); 862 goto error; 863 } 864 865 dfid = v9fs_parent_fid(new_dentry); 866 newdirfid = clone_fid(dfid); 867 p9_fid_put(dfid); 868 dfid = NULL; 869 870 if (IS_ERR(newdirfid)) { 871 retval = PTR_ERR(newdirfid); 872 goto error; 873 } 874 875 down_write(&v9ses->rename_sem); 876 if (v9fs_proto_dotl(v9ses)) { 877 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name, 878 newdirfid, new_dentry->d_name.name); 879 if (retval == -EOPNOTSUPP) 880 retval = p9_client_rename(oldfid, newdirfid, 881 new_dentry->d_name.name); 882 if (retval != -EOPNOTSUPP) 883 goto error_locked; 884 } 885 if (old_dentry->d_parent != new_dentry->d_parent) { 886 /* 887 * 9P .u can only handle file rename in the same directory 888 */ 889 890 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n"); 891 retval = -EXDEV; 892 goto error_locked; 893 } 894 v9fs_blank_wstat(&wstat); 895 wstat.muid = v9ses->uname; 896 wstat.name = new_dentry->d_name.name; 897 retval = p9_client_wstat(oldfid, &wstat); 898 899 error_locked: 900 if (!retval) { 901 if (new_inode) { 902 if (S_ISDIR(new_inode->i_mode)) 903 clear_nlink(new_inode); 904 else 905 v9fs_dec_count(new_inode); 906 } 907 if (S_ISDIR(old_inode->i_mode)) { 908 if (!new_inode) 909 inc_nlink(new_dir); 910 v9fs_dec_count(old_dir); 911 } 912 v9fs_invalidate_inode_attr(old_inode); 913 v9fs_invalidate_inode_attr(old_dir); 914 v9fs_invalidate_inode_attr(new_dir); 915 916 /* successful rename */ 917 d_move(old_dentry, new_dentry); 918 } 919 up_write(&v9ses->rename_sem); 920 921 error: 922 p9_fid_put(newdirfid); 923 p9_fid_put(olddirfid); 924 p9_fid_put(oldfid); 925 return retval; 926 } 927 928 /** 929 * v9fs_vfs_getattr - retrieve file metadata 930 * @idmap: idmap of the mount 931 * @path: Object to query 932 * @stat: metadata structure to populate 933 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests 934 * @flags: AT_STATX_xxx setting 935 * 936 */ 937 938 static int 939 v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path, 940 struct kstat *stat, u32 request_mask, unsigned int flags) 941 { 942 struct dentry *dentry = path->dentry; 943 struct inode *inode = d_inode(dentry); 944 struct v9fs_session_info *v9ses; 945 struct p9_fid *fid; 946 struct p9_wstat *st; 947 948 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry); 949 v9ses = v9fs_dentry2v9ses(dentry); 950 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) { 951 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 952 return 0; 953 } else if (v9ses->cache & CACHE_WRITEBACK) { 954 if (S_ISREG(inode->i_mode)) { 955 int retval = filemap_fdatawrite(inode->i_mapping); 956 957 if (retval) 958 p9_debug(P9_DEBUG_ERROR, 959 "flushing writeback during getattr returned %d\n", retval); 960 } 961 } 962 fid = v9fs_fid_lookup(dentry); 963 if (IS_ERR(fid)) 964 return PTR_ERR(fid); 965 966 st = p9_client_stat(fid); 967 p9_fid_put(fid); 968 if (IS_ERR(st)) 969 return PTR_ERR(st); 970 971 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0); 972 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat); 973 974 p9stat_free(st); 975 kfree(st); 976 return 0; 977 } 978 979 /** 980 * v9fs_vfs_setattr - set file metadata 981 * @idmap: idmap of the mount 982 * @dentry: file whose metadata to set 983 * @iattr: metadata assignment structure 984 * 985 */ 986 987 static int v9fs_vfs_setattr(struct mnt_idmap *idmap, 988 struct dentry *dentry, struct iattr *iattr) 989 { 990 int retval, use_dentry = 0; 991 struct inode *inode = d_inode(dentry); 992 struct v9fs_session_info *v9ses; 993 struct p9_fid *fid = NULL; 994 struct p9_wstat wstat; 995 996 p9_debug(P9_DEBUG_VFS, "\n"); 997 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 998 if (retval) 999 return retval; 1000 1001 v9ses = v9fs_dentry2v9ses(dentry); 1002 if (iattr->ia_valid & ATTR_FILE) { 1003 fid = iattr->ia_file->private_data; 1004 WARN_ON(!fid); 1005 } 1006 if (!fid) { 1007 fid = v9fs_fid_lookup(dentry); 1008 use_dentry = 1; 1009 } 1010 if (IS_ERR(fid)) 1011 return PTR_ERR(fid); 1012 1013 v9fs_blank_wstat(&wstat); 1014 if (iattr->ia_valid & ATTR_MODE) 1015 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode); 1016 1017 if (iattr->ia_valid & ATTR_MTIME) 1018 wstat.mtime = iattr->ia_mtime.tv_sec; 1019 1020 if (iattr->ia_valid & ATTR_ATIME) 1021 wstat.atime = iattr->ia_atime.tv_sec; 1022 1023 if (iattr->ia_valid & ATTR_SIZE) 1024 wstat.length = iattr->ia_size; 1025 1026 if (v9fs_proto_dotu(v9ses)) { 1027 if (iattr->ia_valid & ATTR_UID) 1028 wstat.n_uid = iattr->ia_uid; 1029 1030 if (iattr->ia_valid & ATTR_GID) 1031 wstat.n_gid = iattr->ia_gid; 1032 } 1033 1034 /* Write all dirty data */ 1035 if (d_is_reg(dentry)) { 1036 retval = filemap_fdatawrite(inode->i_mapping); 1037 if (retval) 1038 p9_debug(P9_DEBUG_ERROR, 1039 "flushing writeback during setattr returned %d\n", retval); 1040 } 1041 1042 retval = p9_client_wstat(fid, &wstat); 1043 1044 if (use_dentry) 1045 p9_fid_put(fid); 1046 1047 if (retval < 0) 1048 return retval; 1049 1050 if ((iattr->ia_valid & ATTR_SIZE) && 1051 iattr->ia_size != i_size_read(inode)) { 1052 truncate_setsize(inode, iattr->ia_size); 1053 netfs_resize_file(netfs_inode(inode), iattr->ia_size, true); 1054 1055 #ifdef CONFIG_9P_FSCACHE 1056 if (v9ses->cache & CACHE_FSCACHE) { 1057 struct v9fs_inode *v9inode = V9FS_I(inode); 1058 1059 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size); 1060 } 1061 #endif 1062 } 1063 1064 v9fs_invalidate_inode_attr(inode); 1065 1066 setattr_copy(&nop_mnt_idmap, inode, iattr); 1067 mark_inode_dirty(inode); 1068 return 0; 1069 } 1070 1071 /** 1072 * v9fs_stat2inode - populate an inode structure with mistat info 1073 * @stat: Plan 9 metadata (mistat) structure 1074 * @inode: inode to populate 1075 * @sb: superblock of filesystem 1076 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE) 1077 * 1078 */ 1079 1080 void 1081 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, 1082 struct super_block *sb, unsigned int flags) 1083 { 1084 umode_t mode; 1085 struct v9fs_session_info *v9ses = sb->s_fs_info; 1086 struct v9fs_inode *v9inode = V9FS_I(inode); 1087 1088 inode_set_atime(inode, stat->atime, 0); 1089 inode_set_mtime(inode, stat->mtime, 0); 1090 inode_set_ctime(inode, stat->mtime, 0); 1091 1092 inode->i_uid = v9ses->dfltuid; 1093 inode->i_gid = v9ses->dfltgid; 1094 1095 if (v9fs_proto_dotu(v9ses)) { 1096 inode->i_uid = stat->n_uid; 1097 inode->i_gid = stat->n_gid; 1098 } 1099 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) { 1100 if (v9fs_proto_dotu(v9ses)) { 1101 unsigned int i_nlink; 1102 /* 1103 * Hadlink support got added later to the .u extension. 1104 * So there can be a server out there that doesn't 1105 * support this even with .u extension. That would 1106 * just leave us with stat->extension being an empty 1107 * string, though. 1108 */ 1109 /* HARDLINKCOUNT %u */ 1110 if (sscanf(stat->extension, 1111 " HARDLINKCOUNT %u", &i_nlink) == 1) 1112 set_nlink(inode, i_nlink); 1113 } 1114 } 1115 mode = p9mode2perm(v9ses, stat); 1116 mode |= inode->i_mode & ~S_IALLUGO; 1117 inode->i_mode = mode; 1118 1119 v9inode->netfs.remote_i_size = stat->length; 1120 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) 1121 v9fs_i_size_write(inode, stat->length); 1122 /* not real number of blocks, but 512 byte ones ... */ 1123 inode->i_blocks = (stat->length + 512 - 1) >> 9; 1124 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR; 1125 } 1126 1127 /** 1128 * v9fs_vfs_get_link - follow a symlink path 1129 * @dentry: dentry for symlink 1130 * @inode: inode for symlink 1131 * @done: delayed call for when we are done with the return value 1132 */ 1133 1134 static const char *v9fs_vfs_get_link(struct dentry *dentry, 1135 struct inode *inode, 1136 struct delayed_call *done) 1137 { 1138 struct v9fs_session_info *v9ses; 1139 struct p9_fid *fid; 1140 struct p9_wstat *st; 1141 char *res; 1142 1143 if (!dentry) 1144 return ERR_PTR(-ECHILD); 1145 1146 v9ses = v9fs_dentry2v9ses(dentry); 1147 if (!v9fs_proto_dotu(v9ses)) 1148 return ERR_PTR(-EBADF); 1149 1150 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); 1151 fid = v9fs_fid_lookup(dentry); 1152 1153 if (IS_ERR(fid)) 1154 return ERR_CAST(fid); 1155 1156 st = p9_client_stat(fid); 1157 p9_fid_put(fid); 1158 if (IS_ERR(st)) 1159 return ERR_CAST(st); 1160 1161 if (!(st->mode & P9_DMSYMLINK)) { 1162 p9stat_free(st); 1163 kfree(st); 1164 return ERR_PTR(-EINVAL); 1165 } 1166 res = st->extension; 1167 st->extension = NULL; 1168 if (strlen(res) >= PATH_MAX) 1169 res[PATH_MAX - 1] = '\0'; 1170 1171 p9stat_free(st); 1172 kfree(st); 1173 set_delayed_call(done, kfree_link, res); 1174 return res; 1175 } 1176 1177 /** 1178 * v9fs_vfs_mkspecial - create a special file 1179 * @dir: inode to create special file in 1180 * @dentry: dentry to create 1181 * @perm: mode to create special file 1182 * @extension: 9p2000.u format extension string representing special file 1183 * 1184 */ 1185 1186 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, 1187 u32 perm, const char *extension) 1188 { 1189 struct p9_fid *fid; 1190 struct v9fs_session_info *v9ses; 1191 1192 v9ses = v9fs_inode2v9ses(dir); 1193 if (!v9fs_proto_dotu(v9ses)) { 1194 p9_debug(P9_DEBUG_ERROR, "not extended\n"); 1195 return -EPERM; 1196 } 1197 1198 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm, 1199 P9_OREAD); 1200 if (IS_ERR(fid)) 1201 return PTR_ERR(fid); 1202 1203 v9fs_invalidate_inode_attr(dir); 1204 p9_fid_put(fid); 1205 return 0; 1206 } 1207 1208 /** 1209 * v9fs_vfs_symlink - helper function to create symlinks 1210 * @idmap: idmap of the mount 1211 * @dir: directory inode containing symlink 1212 * @dentry: dentry for symlink 1213 * @symname: symlink data 1214 * 1215 * See Also: 9P2000.u RFC for more information 1216 * 1217 */ 1218 1219 static int 1220 v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir, 1221 struct dentry *dentry, const char *symname) 1222 { 1223 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n", 1224 dir->i_ino, dentry, symname); 1225 1226 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname); 1227 } 1228 1229 #define U32_MAX_DIGITS 10 1230 1231 /** 1232 * v9fs_vfs_link - create a hardlink 1233 * @old_dentry: dentry for file to link to 1234 * @dir: inode destination for new link 1235 * @dentry: dentry for link 1236 * 1237 */ 1238 1239 static int 1240 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir, 1241 struct dentry *dentry) 1242 { 1243 int retval; 1244 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */ 1245 struct p9_fid *oldfid; 1246 1247 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n", 1248 dir->i_ino, dentry, old_dentry); 1249 1250 oldfid = v9fs_fid_clone(old_dentry); 1251 if (IS_ERR(oldfid)) 1252 return PTR_ERR(oldfid); 1253 1254 sprintf(name, "%d\n", oldfid->fid); 1255 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name); 1256 if (!retval) { 1257 v9fs_refresh_inode(oldfid, d_inode(old_dentry)); 1258 v9fs_invalidate_inode_attr(dir); 1259 } 1260 p9_fid_put(oldfid); 1261 return retval; 1262 } 1263 1264 /** 1265 * v9fs_vfs_mknod - create a special file 1266 * @idmap: idmap of the mount 1267 * @dir: inode destination for new link 1268 * @dentry: dentry for file 1269 * @mode: mode for creation 1270 * @rdev: device associated with special file 1271 * 1272 */ 1273 1274 static int 1275 v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, 1276 struct dentry *dentry, umode_t mode, dev_t rdev) 1277 { 1278 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 1279 int retval; 1280 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1]; 1281 u32 perm; 1282 1283 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n", 1284 dir->i_ino, dentry, mode, 1285 MAJOR(rdev), MINOR(rdev)); 1286 1287 /* build extension */ 1288 if (S_ISBLK(mode)) 1289 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev)); 1290 else if (S_ISCHR(mode)) 1291 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev)); 1292 else 1293 *name = 0; 1294 1295 perm = unixmode2p9mode(v9ses, mode); 1296 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name); 1297 1298 return retval; 1299 } 1300 1301 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) 1302 { 1303 int umode; 1304 dev_t rdev; 1305 struct p9_wstat *st; 1306 struct v9fs_session_info *v9ses; 1307 unsigned int flags; 1308 1309 v9ses = v9fs_inode2v9ses(inode); 1310 st = p9_client_stat(fid); 1311 if (IS_ERR(st)) 1312 return PTR_ERR(st); 1313 /* 1314 * Don't update inode if the file type is different 1315 */ 1316 umode = p9mode2unixmode(v9ses, st, &rdev); 1317 if (inode_wrong_type(inode, umode)) 1318 goto out; 1319 1320 /* 1321 * We don't want to refresh inode->i_size, 1322 * because we may have cached data 1323 */ 1324 flags = (v9ses->cache & CACHE_LOOSE) ? 1325 V9FS_STAT2INODE_KEEP_ISIZE : 0; 1326 v9fs_stat2inode(st, inode, inode->i_sb, flags); 1327 out: 1328 p9stat_free(st); 1329 kfree(st); 1330 return 0; 1331 } 1332 1333 static const struct inode_operations v9fs_dir_inode_operations_dotu = { 1334 .create = v9fs_vfs_create, 1335 .lookup = v9fs_vfs_lookup, 1336 .atomic_open = v9fs_vfs_atomic_open, 1337 .symlink = v9fs_vfs_symlink, 1338 .link = v9fs_vfs_link, 1339 .unlink = v9fs_vfs_unlink, 1340 .mkdir = v9fs_vfs_mkdir, 1341 .rmdir = v9fs_vfs_rmdir, 1342 .mknod = v9fs_vfs_mknod, 1343 .rename = v9fs_vfs_rename, 1344 .getattr = v9fs_vfs_getattr, 1345 .setattr = v9fs_vfs_setattr, 1346 }; 1347 1348 static const struct inode_operations v9fs_dir_inode_operations = { 1349 .create = v9fs_vfs_create, 1350 .lookup = v9fs_vfs_lookup, 1351 .atomic_open = v9fs_vfs_atomic_open, 1352 .unlink = v9fs_vfs_unlink, 1353 .mkdir = v9fs_vfs_mkdir, 1354 .rmdir = v9fs_vfs_rmdir, 1355 .mknod = v9fs_vfs_mknod, 1356 .rename = v9fs_vfs_rename, 1357 .getattr = v9fs_vfs_getattr, 1358 .setattr = v9fs_vfs_setattr, 1359 }; 1360 1361 static const struct inode_operations v9fs_file_inode_operations = { 1362 .getattr = v9fs_vfs_getattr, 1363 .setattr = v9fs_vfs_setattr, 1364 }; 1365 1366 static const struct inode_operations v9fs_symlink_inode_operations = { 1367 .get_link = v9fs_vfs_get_link, 1368 .getattr = v9fs_vfs_getattr, 1369 .setattr = v9fs_vfs_setattr, 1370 }; 1371 1372