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 netfs_wait_for_outstanding_io(inode); 352 truncate_inode_pages_final(&inode->i_data); 353 354 version = cpu_to_le32(v9inode->qid.version); 355 netfs_clear_inode_writeback(inode, &version); 356 357 clear_inode(inode); 358 filemap_fdatawrite(&inode->i_data); 359 360 #ifdef CONFIG_9P_FSCACHE 361 if (v9fs_inode_cookie(v9inode)) 362 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); 363 #endif 364 } else 365 clear_inode(inode); 366 } 367 368 struct inode * 369 v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid, bool new) 370 { 371 dev_t rdev; 372 int retval; 373 umode_t umode; 374 struct inode *inode; 375 struct p9_wstat *st; 376 struct v9fs_session_info *v9ses = sb->s_fs_info; 377 378 inode = iget_locked(sb, QID2INO(&fid->qid)); 379 if (unlikely(!inode)) 380 return ERR_PTR(-ENOMEM); 381 if (!(inode->i_state & I_NEW)) { 382 if (!new) { 383 goto done; 384 } else { 385 p9_debug(P9_DEBUG_VFS, "WARNING: Inode collision %ld\n", 386 inode->i_ino); 387 iput(inode); 388 remove_inode_hash(inode); 389 inode = iget_locked(sb, QID2INO(&fid->qid)); 390 WARN_ON(!(inode->i_state & I_NEW)); 391 } 392 } 393 394 /* 395 * initialize the inode with the stat info 396 * FIXME!! we may need support for stale inodes 397 * later. 398 */ 399 st = p9_client_stat(fid); 400 if (IS_ERR(st)) { 401 retval = PTR_ERR(st); 402 goto error; 403 } 404 405 umode = p9mode2unixmode(v9ses, st, &rdev); 406 retval = v9fs_init_inode(v9ses, inode, &fid->qid, umode, rdev); 407 v9fs_stat2inode(st, inode, sb, 0); 408 p9stat_free(st); 409 kfree(st); 410 if (retval) 411 goto error; 412 413 v9fs_set_netfs_context(inode); 414 v9fs_cache_inode_get_cookie(inode); 415 unlock_new_inode(inode); 416 done: 417 return inode; 418 error: 419 iget_failed(inode); 420 return ERR_PTR(retval); 421 } 422 423 /** 424 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to 425 * plan 9 AT flag. 426 * @flags: flags to convert 427 */ 428 static int v9fs_at_to_dotl_flags(int flags) 429 { 430 int rflags = 0; 431 432 if (flags & AT_REMOVEDIR) 433 rflags |= P9_DOTL_AT_REMOVEDIR; 434 435 return rflags; 436 } 437 438 /** 439 * v9fs_dec_count - helper functon to drop i_nlink. 440 * 441 * If a directory had nlink <= 2 (including . and ..), then we should not drop 442 * the link count, which indicates the underlying exported fs doesn't maintain 443 * nlink accurately. e.g. 444 * - overlayfs sets nlink to 1 for merged dir 445 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more 446 * than EXT4_LINK_MAX (65000) links. 447 * 448 * @inode: inode whose nlink is being dropped 449 */ 450 static void v9fs_dec_count(struct inode *inode) 451 { 452 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) { 453 if (inode->i_nlink) { 454 drop_nlink(inode); 455 } else { 456 p9_debug(P9_DEBUG_VFS, 457 "WARNING: unexpected i_nlink zero %d inode %ld\n", 458 inode->i_nlink, inode->i_ino); 459 } 460 } 461 } 462 463 /** 464 * v9fs_remove - helper function to remove files and directories 465 * @dir: directory inode that is being deleted 466 * @dentry: dentry that is being deleted 467 * @flags: removing a directory 468 * 469 */ 470 471 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) 472 { 473 struct inode *inode; 474 int retval = -EOPNOTSUPP; 475 struct p9_fid *v9fid, *dfid; 476 struct v9fs_session_info *v9ses; 477 478 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n", 479 dir, dentry, flags); 480 481 v9ses = v9fs_inode2v9ses(dir); 482 inode = d_inode(dentry); 483 dfid = v9fs_parent_fid(dentry); 484 if (IS_ERR(dfid)) { 485 retval = PTR_ERR(dfid); 486 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval); 487 return retval; 488 } 489 if (v9fs_proto_dotl(v9ses)) 490 retval = p9_client_unlinkat(dfid, dentry->d_name.name, 491 v9fs_at_to_dotl_flags(flags)); 492 p9_fid_put(dfid); 493 if (retval == -EOPNOTSUPP) { 494 /* Try the one based on path */ 495 v9fid = v9fs_fid_clone(dentry); 496 if (IS_ERR(v9fid)) 497 return PTR_ERR(v9fid); 498 retval = p9_client_remove(v9fid); 499 } 500 if (!retval) { 501 /* 502 * directories on unlink should have zero 503 * link count 504 */ 505 if (flags & AT_REMOVEDIR) { 506 clear_nlink(inode); 507 v9fs_dec_count(dir); 508 } else 509 v9fs_dec_count(inode); 510 511 if (inode->i_nlink <= 0) /* no more refs unhash it */ 512 remove_inode_hash(inode); 513 514 v9fs_invalidate_inode_attr(inode); 515 v9fs_invalidate_inode_attr(dir); 516 517 /* invalidate all fids associated with dentry */ 518 /* NOTE: This will not include open fids */ 519 dentry->d_op->d_release(dentry); 520 } 521 return retval; 522 } 523 524 /** 525 * v9fs_create - Create a file 526 * @v9ses: session information 527 * @dir: directory that dentry is being created in 528 * @dentry: dentry that is being created 529 * @extension: 9p2000.u extension string to support devices, etc. 530 * @perm: create permissions 531 * @mode: open mode 532 * 533 */ 534 static struct p9_fid * 535 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 536 struct dentry *dentry, char *extension, u32 perm, u8 mode) 537 { 538 int err; 539 const unsigned char *name; 540 struct p9_fid *dfid, *ofid = NULL, *fid = NULL; 541 struct inode *inode; 542 543 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 544 545 name = dentry->d_name.name; 546 dfid = v9fs_parent_fid(dentry); 547 if (IS_ERR(dfid)) { 548 err = PTR_ERR(dfid); 549 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err); 550 return ERR_PTR(err); 551 } 552 553 /* clone a fid to use for creation */ 554 ofid = clone_fid(dfid); 555 if (IS_ERR(ofid)) { 556 err = PTR_ERR(ofid); 557 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); 558 goto error; 559 } 560 561 err = p9_client_fcreate(ofid, name, perm, mode, extension); 562 if (err < 0) { 563 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); 564 goto error; 565 } 566 567 if (!(perm & P9_DMLINK)) { 568 /* now walk from the parent so we can get unopened fid */ 569 fid = p9_client_walk(dfid, 1, &name, 1); 570 if (IS_ERR(fid)) { 571 err = PTR_ERR(fid); 572 p9_debug(P9_DEBUG_VFS, 573 "p9_client_walk failed %d\n", err); 574 goto error; 575 } 576 /* 577 * instantiate inode and assign the unopened fid to the dentry 578 */ 579 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, true); 580 if (IS_ERR(inode)) { 581 err = PTR_ERR(inode); 582 p9_debug(P9_DEBUG_VFS, 583 "inode creation failed %d\n", err); 584 goto error; 585 } 586 v9fs_fid_add(dentry, &fid); 587 d_instantiate(dentry, inode); 588 } 589 p9_fid_put(dfid); 590 return ofid; 591 error: 592 p9_fid_put(dfid); 593 p9_fid_put(ofid); 594 p9_fid_put(fid); 595 return ERR_PTR(err); 596 } 597 598 /** 599 * v9fs_vfs_create - VFS hook to create a regular file 600 * @idmap: idmap of the mount 601 * @dir: The parent directory 602 * @dentry: The name of file to be created 603 * @mode: The UNIX file mode to set 604 * @excl: True if the file must not yet exist 605 * 606 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called 607 * for mknod(2). 608 * 609 */ 610 611 static int 612 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir, 613 struct dentry *dentry, umode_t mode, bool excl) 614 { 615 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 616 u32 perm = unixmode2p9mode(v9ses, mode); 617 struct p9_fid *fid; 618 619 /* P9_OEXCL? */ 620 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR); 621 if (IS_ERR(fid)) 622 return PTR_ERR(fid); 623 624 v9fs_invalidate_inode_attr(dir); 625 p9_fid_put(fid); 626 627 return 0; 628 } 629 630 /** 631 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory 632 * @idmap: idmap of the mount 633 * @dir: inode that is being unlinked 634 * @dentry: dentry that is being unlinked 635 * @mode: mode for new directory 636 * 637 */ 638 639 static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir, 640 struct dentry *dentry, umode_t mode) 641 { 642 int err; 643 u32 perm; 644 struct p9_fid *fid; 645 struct v9fs_session_info *v9ses; 646 647 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 648 err = 0; 649 v9ses = v9fs_inode2v9ses(dir); 650 perm = unixmode2p9mode(v9ses, mode | S_IFDIR); 651 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD); 652 if (IS_ERR(fid)) { 653 err = PTR_ERR(fid); 654 fid = NULL; 655 } else { 656 inc_nlink(dir); 657 v9fs_invalidate_inode_attr(dir); 658 } 659 660 if (fid) 661 p9_fid_put(fid); 662 663 return err; 664 } 665 666 /** 667 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode 668 * @dir: inode that is being walked from 669 * @dentry: dentry that is being walked to? 670 * @flags: lookup flags (unused) 671 * 672 */ 673 674 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, 675 unsigned int flags) 676 { 677 struct dentry *res; 678 struct v9fs_session_info *v9ses; 679 struct p9_fid *dfid, *fid; 680 struct inode *inode; 681 const unsigned char *name; 682 683 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n", 684 dir, dentry, dentry, flags); 685 686 if (dentry->d_name.len > NAME_MAX) 687 return ERR_PTR(-ENAMETOOLONG); 688 689 v9ses = v9fs_inode2v9ses(dir); 690 /* We can walk d_parent because we hold the dir->i_mutex */ 691 dfid = v9fs_parent_fid(dentry); 692 if (IS_ERR(dfid)) 693 return ERR_CAST(dfid); 694 695 /* 696 * Make sure we don't use a wrong inode due to parallel 697 * unlink. For cached mode create calls request for new 698 * inode. But with cache disabled, lookup should do this. 699 */ 700 name = dentry->d_name.name; 701 fid = p9_client_walk(dfid, 1, &name, 1); 702 p9_fid_put(dfid); 703 if (fid == ERR_PTR(-ENOENT)) 704 inode = NULL; 705 else if (IS_ERR(fid)) 706 inode = ERR_CAST(fid); 707 else 708 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, false); 709 /* 710 * If we had a rename on the server and a parallel lookup 711 * for the new name, then make sure we instantiate with 712 * the new name. ie look up for a/b, while on server somebody 713 * moved b under k and client parallely did a lookup for 714 * k/b. 715 */ 716 res = d_splice_alias(inode, dentry); 717 if (!IS_ERR(fid)) { 718 if (!res) 719 v9fs_fid_add(dentry, &fid); 720 else if (!IS_ERR(res)) 721 v9fs_fid_add(res, &fid); 722 else 723 p9_fid_put(fid); 724 } 725 return res; 726 } 727 728 static int 729 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, 730 struct file *file, unsigned int flags, umode_t mode) 731 { 732 int err; 733 u32 perm; 734 struct v9fs_inode __maybe_unused *v9inode; 735 struct v9fs_session_info *v9ses; 736 struct p9_fid *fid; 737 struct dentry *res = NULL; 738 struct inode *inode; 739 int p9_omode; 740 741 if (d_in_lookup(dentry)) { 742 res = v9fs_vfs_lookup(dir, dentry, 0); 743 if (IS_ERR(res)) 744 return PTR_ERR(res); 745 746 if (res) 747 dentry = res; 748 } 749 750 /* Only creates */ 751 if (!(flags & O_CREAT) || d_really_is_positive(dentry)) 752 return finish_no_open(file, res); 753 754 v9ses = v9fs_inode2v9ses(dir); 755 perm = unixmode2p9mode(v9ses, mode); 756 p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses)); 757 758 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) { 759 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR; 760 p9_debug(P9_DEBUG_CACHE, 761 "write-only file with writeback enabled, creating w/ O_RDWR\n"); 762 } 763 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode); 764 if (IS_ERR(fid)) { 765 err = PTR_ERR(fid); 766 goto error; 767 } 768 769 v9fs_invalidate_inode_attr(dir); 770 inode = d_inode(dentry); 771 v9inode = V9FS_I(inode); 772 err = finish_open(file, dentry, generic_file_open); 773 if (err) 774 goto error; 775 776 file->private_data = fid; 777 #ifdef CONFIG_9P_FSCACHE 778 if (v9ses->cache & CACHE_FSCACHE) 779 fscache_use_cookie(v9fs_inode_cookie(v9inode), 780 file->f_mode & FMODE_WRITE); 781 #endif 782 783 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags); 784 v9fs_open_fid_add(inode, &fid); 785 786 file->f_mode |= FMODE_CREATED; 787 out: 788 dput(res); 789 return err; 790 791 error: 792 p9_fid_put(fid); 793 goto out; 794 } 795 796 /** 797 * v9fs_vfs_unlink - VFS unlink hook to delete an inode 798 * @i: inode that is being unlinked 799 * @d: dentry that is being unlinked 800 * 801 */ 802 803 int v9fs_vfs_unlink(struct inode *i, struct dentry *d) 804 { 805 return v9fs_remove(i, d, 0); 806 } 807 808 /** 809 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory 810 * @i: inode that is being unlinked 811 * @d: dentry that is being unlinked 812 * 813 */ 814 815 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d) 816 { 817 return v9fs_remove(i, d, AT_REMOVEDIR); 818 } 819 820 /** 821 * v9fs_vfs_rename - VFS hook to rename an inode 822 * @idmap: The idmap of the mount 823 * @old_dir: old dir inode 824 * @old_dentry: old dentry 825 * @new_dir: new dir inode 826 * @new_dentry: new dentry 827 * @flags: RENAME_* flags 828 * 829 */ 830 831 int 832 v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, 833 struct dentry *old_dentry, struct inode *new_dir, 834 struct dentry *new_dentry, unsigned int flags) 835 { 836 int retval; 837 struct inode *old_inode; 838 struct inode *new_inode; 839 struct v9fs_session_info *v9ses; 840 struct p9_fid *oldfid = NULL, *dfid = NULL; 841 struct p9_fid *olddirfid = NULL; 842 struct p9_fid *newdirfid = NULL; 843 struct p9_wstat wstat; 844 845 if (flags) 846 return -EINVAL; 847 848 p9_debug(P9_DEBUG_VFS, "\n"); 849 old_inode = d_inode(old_dentry); 850 new_inode = d_inode(new_dentry); 851 v9ses = v9fs_inode2v9ses(old_inode); 852 oldfid = v9fs_fid_lookup(old_dentry); 853 if (IS_ERR(oldfid)) 854 return PTR_ERR(oldfid); 855 856 dfid = v9fs_parent_fid(old_dentry); 857 olddirfid = clone_fid(dfid); 858 p9_fid_put(dfid); 859 dfid = NULL; 860 861 if (IS_ERR(olddirfid)) { 862 retval = PTR_ERR(olddirfid); 863 goto error; 864 } 865 866 dfid = v9fs_parent_fid(new_dentry); 867 newdirfid = clone_fid(dfid); 868 p9_fid_put(dfid); 869 dfid = NULL; 870 871 if (IS_ERR(newdirfid)) { 872 retval = PTR_ERR(newdirfid); 873 goto error; 874 } 875 876 down_write(&v9ses->rename_sem); 877 if (v9fs_proto_dotl(v9ses)) { 878 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name, 879 newdirfid, new_dentry->d_name.name); 880 if (retval == -EOPNOTSUPP) 881 retval = p9_client_rename(oldfid, newdirfid, 882 new_dentry->d_name.name); 883 if (retval != -EOPNOTSUPP) 884 goto error_locked; 885 } 886 if (old_dentry->d_parent != new_dentry->d_parent) { 887 /* 888 * 9P .u can only handle file rename in the same directory 889 */ 890 891 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n"); 892 retval = -EXDEV; 893 goto error_locked; 894 } 895 v9fs_blank_wstat(&wstat); 896 wstat.muid = v9ses->uname; 897 wstat.name = new_dentry->d_name.name; 898 retval = p9_client_wstat(oldfid, &wstat); 899 900 error_locked: 901 if (!retval) { 902 if (new_inode) { 903 if (S_ISDIR(new_inode->i_mode)) 904 clear_nlink(new_inode); 905 else 906 v9fs_dec_count(new_inode); 907 } 908 if (S_ISDIR(old_inode->i_mode)) { 909 if (!new_inode) 910 inc_nlink(new_dir); 911 v9fs_dec_count(old_dir); 912 } 913 v9fs_invalidate_inode_attr(old_inode); 914 v9fs_invalidate_inode_attr(old_dir); 915 v9fs_invalidate_inode_attr(new_dir); 916 917 /* successful rename */ 918 d_move(old_dentry, new_dentry); 919 } 920 up_write(&v9ses->rename_sem); 921 922 error: 923 p9_fid_put(newdirfid); 924 p9_fid_put(olddirfid); 925 p9_fid_put(oldfid); 926 return retval; 927 } 928 929 /** 930 * v9fs_vfs_getattr - retrieve file metadata 931 * @idmap: idmap of the mount 932 * @path: Object to query 933 * @stat: metadata structure to populate 934 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests 935 * @flags: AT_STATX_xxx setting 936 * 937 */ 938 939 static int 940 v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path, 941 struct kstat *stat, u32 request_mask, unsigned int flags) 942 { 943 struct dentry *dentry = path->dentry; 944 struct inode *inode = d_inode(dentry); 945 struct v9fs_session_info *v9ses; 946 struct p9_fid *fid; 947 struct p9_wstat *st; 948 949 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry); 950 v9ses = v9fs_dentry2v9ses(dentry); 951 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) { 952 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 953 return 0; 954 } else if (v9ses->cache & CACHE_WRITEBACK) { 955 if (S_ISREG(inode->i_mode)) { 956 int retval = filemap_fdatawrite(inode->i_mapping); 957 958 if (retval) 959 p9_debug(P9_DEBUG_ERROR, 960 "flushing writeback during getattr returned %d\n", retval); 961 } 962 } 963 fid = v9fs_fid_lookup(dentry); 964 if (IS_ERR(fid)) 965 return PTR_ERR(fid); 966 967 st = p9_client_stat(fid); 968 p9_fid_put(fid); 969 if (IS_ERR(st)) 970 return PTR_ERR(st); 971 972 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0); 973 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat); 974 975 p9stat_free(st); 976 kfree(st); 977 return 0; 978 } 979 980 /** 981 * v9fs_vfs_setattr - set file metadata 982 * @idmap: idmap of the mount 983 * @dentry: file whose metadata to set 984 * @iattr: metadata assignment structure 985 * 986 */ 987 988 static int v9fs_vfs_setattr(struct mnt_idmap *idmap, 989 struct dentry *dentry, struct iattr *iattr) 990 { 991 int retval, use_dentry = 0; 992 struct inode *inode = d_inode(dentry); 993 struct v9fs_session_info *v9ses; 994 struct p9_fid *fid = NULL; 995 struct p9_wstat wstat; 996 997 p9_debug(P9_DEBUG_VFS, "\n"); 998 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 999 if (retval) 1000 return retval; 1001 1002 v9ses = v9fs_dentry2v9ses(dentry); 1003 if (iattr->ia_valid & ATTR_FILE) { 1004 fid = iattr->ia_file->private_data; 1005 WARN_ON(!fid); 1006 } 1007 if (!fid) { 1008 fid = v9fs_fid_lookup(dentry); 1009 use_dentry = 1; 1010 } 1011 if (IS_ERR(fid)) 1012 return PTR_ERR(fid); 1013 1014 v9fs_blank_wstat(&wstat); 1015 if (iattr->ia_valid & ATTR_MODE) 1016 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode); 1017 1018 if (iattr->ia_valid & ATTR_MTIME) 1019 wstat.mtime = iattr->ia_mtime.tv_sec; 1020 1021 if (iattr->ia_valid & ATTR_ATIME) 1022 wstat.atime = iattr->ia_atime.tv_sec; 1023 1024 if (iattr->ia_valid & ATTR_SIZE) 1025 wstat.length = iattr->ia_size; 1026 1027 if (v9fs_proto_dotu(v9ses)) { 1028 if (iattr->ia_valid & ATTR_UID) 1029 wstat.n_uid = iattr->ia_uid; 1030 1031 if (iattr->ia_valid & ATTR_GID) 1032 wstat.n_gid = iattr->ia_gid; 1033 } 1034 1035 /* Write all dirty data */ 1036 if (d_is_reg(dentry)) { 1037 retval = filemap_fdatawrite(inode->i_mapping); 1038 if (retval) 1039 p9_debug(P9_DEBUG_ERROR, 1040 "flushing writeback during setattr returned %d\n", retval); 1041 } 1042 1043 retval = p9_client_wstat(fid, &wstat); 1044 1045 if (use_dentry) 1046 p9_fid_put(fid); 1047 1048 if (retval < 0) 1049 return retval; 1050 1051 if ((iattr->ia_valid & ATTR_SIZE) && 1052 iattr->ia_size != i_size_read(inode)) { 1053 truncate_setsize(inode, iattr->ia_size); 1054 netfs_resize_file(netfs_inode(inode), iattr->ia_size, true); 1055 1056 #ifdef CONFIG_9P_FSCACHE 1057 if (v9ses->cache & CACHE_FSCACHE) { 1058 struct v9fs_inode *v9inode = V9FS_I(inode); 1059 1060 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size); 1061 } 1062 #endif 1063 } 1064 1065 v9fs_invalidate_inode_attr(inode); 1066 1067 setattr_copy(&nop_mnt_idmap, inode, iattr); 1068 mark_inode_dirty(inode); 1069 return 0; 1070 } 1071 1072 /** 1073 * v9fs_stat2inode - populate an inode structure with mistat info 1074 * @stat: Plan 9 metadata (mistat) structure 1075 * @inode: inode to populate 1076 * @sb: superblock of filesystem 1077 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE) 1078 * 1079 */ 1080 1081 void 1082 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, 1083 struct super_block *sb, unsigned int flags) 1084 { 1085 umode_t mode; 1086 struct v9fs_session_info *v9ses = sb->s_fs_info; 1087 struct v9fs_inode *v9inode = V9FS_I(inode); 1088 1089 inode_set_atime(inode, stat->atime, 0); 1090 inode_set_mtime(inode, stat->mtime, 0); 1091 inode_set_ctime(inode, stat->mtime, 0); 1092 1093 inode->i_uid = v9ses->dfltuid; 1094 inode->i_gid = v9ses->dfltgid; 1095 1096 if (v9fs_proto_dotu(v9ses)) { 1097 inode->i_uid = stat->n_uid; 1098 inode->i_gid = stat->n_gid; 1099 } 1100 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) { 1101 if (v9fs_proto_dotu(v9ses)) { 1102 unsigned int i_nlink; 1103 /* 1104 * Hadlink support got added later to the .u extension. 1105 * So there can be a server out there that doesn't 1106 * support this even with .u extension. That would 1107 * just leave us with stat->extension being an empty 1108 * string, though. 1109 */ 1110 /* HARDLINKCOUNT %u */ 1111 if (sscanf(stat->extension, 1112 " HARDLINKCOUNT %u", &i_nlink) == 1) 1113 set_nlink(inode, i_nlink); 1114 } 1115 } 1116 mode = p9mode2perm(v9ses, stat); 1117 mode |= inode->i_mode & ~S_IALLUGO; 1118 inode->i_mode = mode; 1119 1120 v9inode->netfs.remote_i_size = stat->length; 1121 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) 1122 v9fs_i_size_write(inode, stat->length); 1123 /* not real number of blocks, but 512 byte ones ... */ 1124 inode->i_blocks = (stat->length + 512 - 1) >> 9; 1125 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR; 1126 } 1127 1128 /** 1129 * v9fs_vfs_get_link - follow a symlink path 1130 * @dentry: dentry for symlink 1131 * @inode: inode for symlink 1132 * @done: delayed call for when we are done with the return value 1133 */ 1134 1135 static const char *v9fs_vfs_get_link(struct dentry *dentry, 1136 struct inode *inode, 1137 struct delayed_call *done) 1138 { 1139 struct v9fs_session_info *v9ses; 1140 struct p9_fid *fid; 1141 struct p9_wstat *st; 1142 char *res; 1143 1144 if (!dentry) 1145 return ERR_PTR(-ECHILD); 1146 1147 v9ses = v9fs_dentry2v9ses(dentry); 1148 if (!v9fs_proto_dotu(v9ses)) 1149 return ERR_PTR(-EBADF); 1150 1151 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); 1152 fid = v9fs_fid_lookup(dentry); 1153 1154 if (IS_ERR(fid)) 1155 return ERR_CAST(fid); 1156 1157 st = p9_client_stat(fid); 1158 p9_fid_put(fid); 1159 if (IS_ERR(st)) 1160 return ERR_CAST(st); 1161 1162 if (!(st->mode & P9_DMSYMLINK)) { 1163 p9stat_free(st); 1164 kfree(st); 1165 return ERR_PTR(-EINVAL); 1166 } 1167 res = st->extension; 1168 st->extension = NULL; 1169 if (strlen(res) >= PATH_MAX) 1170 res[PATH_MAX - 1] = '\0'; 1171 1172 p9stat_free(st); 1173 kfree(st); 1174 set_delayed_call(done, kfree_link, res); 1175 return res; 1176 } 1177 1178 /** 1179 * v9fs_vfs_mkspecial - create a special file 1180 * @dir: inode to create special file in 1181 * @dentry: dentry to create 1182 * @perm: mode to create special file 1183 * @extension: 9p2000.u format extension string representing special file 1184 * 1185 */ 1186 1187 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, 1188 u32 perm, const char *extension) 1189 { 1190 struct p9_fid *fid; 1191 struct v9fs_session_info *v9ses; 1192 1193 v9ses = v9fs_inode2v9ses(dir); 1194 if (!v9fs_proto_dotu(v9ses)) { 1195 p9_debug(P9_DEBUG_ERROR, "not extended\n"); 1196 return -EPERM; 1197 } 1198 1199 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm, 1200 P9_OREAD); 1201 if (IS_ERR(fid)) 1202 return PTR_ERR(fid); 1203 1204 v9fs_invalidate_inode_attr(dir); 1205 p9_fid_put(fid); 1206 return 0; 1207 } 1208 1209 /** 1210 * v9fs_vfs_symlink - helper function to create symlinks 1211 * @idmap: idmap of the mount 1212 * @dir: directory inode containing symlink 1213 * @dentry: dentry for symlink 1214 * @symname: symlink data 1215 * 1216 * See Also: 9P2000.u RFC for more information 1217 * 1218 */ 1219 1220 static int 1221 v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir, 1222 struct dentry *dentry, const char *symname) 1223 { 1224 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n", 1225 dir->i_ino, dentry, symname); 1226 1227 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname); 1228 } 1229 1230 #define U32_MAX_DIGITS 10 1231 1232 /** 1233 * v9fs_vfs_link - create a hardlink 1234 * @old_dentry: dentry for file to link to 1235 * @dir: inode destination for new link 1236 * @dentry: dentry for link 1237 * 1238 */ 1239 1240 static int 1241 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir, 1242 struct dentry *dentry) 1243 { 1244 int retval; 1245 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */ 1246 struct p9_fid *oldfid; 1247 1248 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n", 1249 dir->i_ino, dentry, old_dentry); 1250 1251 oldfid = v9fs_fid_clone(old_dentry); 1252 if (IS_ERR(oldfid)) 1253 return PTR_ERR(oldfid); 1254 1255 sprintf(name, "%d\n", oldfid->fid); 1256 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name); 1257 if (!retval) { 1258 v9fs_refresh_inode(oldfid, d_inode(old_dentry)); 1259 v9fs_invalidate_inode_attr(dir); 1260 } 1261 p9_fid_put(oldfid); 1262 return retval; 1263 } 1264 1265 /** 1266 * v9fs_vfs_mknod - create a special file 1267 * @idmap: idmap of the mount 1268 * @dir: inode destination for new link 1269 * @dentry: dentry for file 1270 * @mode: mode for creation 1271 * @rdev: device associated with special file 1272 * 1273 */ 1274 1275 static int 1276 v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, 1277 struct dentry *dentry, umode_t mode, dev_t rdev) 1278 { 1279 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 1280 int retval; 1281 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1]; 1282 u32 perm; 1283 1284 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n", 1285 dir->i_ino, dentry, mode, 1286 MAJOR(rdev), MINOR(rdev)); 1287 1288 /* build extension */ 1289 if (S_ISBLK(mode)) 1290 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev)); 1291 else if (S_ISCHR(mode)) 1292 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev)); 1293 else 1294 *name = 0; 1295 1296 perm = unixmode2p9mode(v9ses, mode); 1297 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name); 1298 1299 return retval; 1300 } 1301 1302 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) 1303 { 1304 int umode; 1305 dev_t rdev; 1306 struct p9_wstat *st; 1307 struct v9fs_session_info *v9ses; 1308 unsigned int flags; 1309 1310 v9ses = v9fs_inode2v9ses(inode); 1311 st = p9_client_stat(fid); 1312 if (IS_ERR(st)) 1313 return PTR_ERR(st); 1314 /* 1315 * Don't update inode if the file type is different 1316 */ 1317 umode = p9mode2unixmode(v9ses, st, &rdev); 1318 if (inode_wrong_type(inode, umode)) 1319 goto out; 1320 1321 /* 1322 * We don't want to refresh inode->i_size, 1323 * because we may have cached data 1324 */ 1325 flags = (v9ses->cache & CACHE_LOOSE) ? 1326 V9FS_STAT2INODE_KEEP_ISIZE : 0; 1327 v9fs_stat2inode(st, inode, inode->i_sb, flags); 1328 out: 1329 p9stat_free(st); 1330 kfree(st); 1331 return 0; 1332 } 1333 1334 static const struct inode_operations v9fs_dir_inode_operations_dotu = { 1335 .create = v9fs_vfs_create, 1336 .lookup = v9fs_vfs_lookup, 1337 .atomic_open = v9fs_vfs_atomic_open, 1338 .symlink = v9fs_vfs_symlink, 1339 .link = v9fs_vfs_link, 1340 .unlink = v9fs_vfs_unlink, 1341 .mkdir = v9fs_vfs_mkdir, 1342 .rmdir = v9fs_vfs_rmdir, 1343 .mknod = v9fs_vfs_mknod, 1344 .rename = v9fs_vfs_rename, 1345 .getattr = v9fs_vfs_getattr, 1346 .setattr = v9fs_vfs_setattr, 1347 }; 1348 1349 static const struct inode_operations v9fs_dir_inode_operations = { 1350 .create = v9fs_vfs_create, 1351 .lookup = v9fs_vfs_lookup, 1352 .atomic_open = v9fs_vfs_atomic_open, 1353 .unlink = v9fs_vfs_unlink, 1354 .mkdir = v9fs_vfs_mkdir, 1355 .rmdir = v9fs_vfs_rmdir, 1356 .mknod = v9fs_vfs_mknod, 1357 .rename = v9fs_vfs_rename, 1358 .getattr = v9fs_vfs_getattr, 1359 .setattr = v9fs_vfs_setattr, 1360 }; 1361 1362 static const struct inode_operations v9fs_file_inode_operations = { 1363 .getattr = v9fs_vfs_getattr, 1364 .setattr = v9fs_vfs_setattr, 1365 }; 1366 1367 static const struct inode_operations v9fs_symlink_inode_operations = { 1368 .get_link = v9fs_vfs_get_link, 1369 .getattr = v9fs_vfs_getattr, 1370 .setattr = v9fs_vfs_setattr, 1371 }; 1372 1373