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