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 33static const struct inode_operations v9fs_dir_inode_operations; 34static const struct inode_operations v9fs_dir_inode_operations_dotu; 35static const struct inode_operations v9fs_file_inode_operations; 36static 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 45static 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 */ 80static 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 */ 107static 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 162int 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 201void 202v9fs_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 */ 227struct 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 244void 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 */ 252void 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 258int 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 } 335error: 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 */ 345void 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 367struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid) 368{ 369 dev_t rdev; 370 int retval; 371 umode_t umode; 372 struct inode *inode; 373 struct p9_wstat *st; 374 struct v9fs_session_info *v9ses = sb->s_fs_info; 375 376 inode = iget_locked(sb, QID2INO(&fid->qid)); 377 if (unlikely(!inode)) 378 return ERR_PTR(-ENOMEM); 379 if (!(inode->i_state & I_NEW)) 380 return inode; 381 382 /* 383 * initialize the inode with the stat info 384 * FIXME!! we may need support for stale inodes 385 * later. 386 */ 387 st = p9_client_stat(fid); 388 if (IS_ERR(st)) { 389 retval = PTR_ERR(st); 390 goto error; 391 } 392 393 umode = p9mode2unixmode(v9ses, st, &rdev); 394 retval = v9fs_init_inode(v9ses, inode, &fid->qid, umode, rdev); 395 v9fs_stat2inode(st, inode, sb, 0); 396 p9stat_free(st); 397 kfree(st); 398 if (retval) 399 goto error; 400 401 v9fs_set_netfs_context(inode); 402 v9fs_cache_inode_get_cookie(inode); 403 unlock_new_inode(inode); 404 return inode; 405error: 406 iget_failed(inode); 407 return ERR_PTR(retval); 408 409} 410 411/** 412 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to 413 * plan 9 AT flag. 414 * @flags: flags to convert 415 */ 416static int v9fs_at_to_dotl_flags(int flags) 417{ 418 int rflags = 0; 419 420 if (flags & AT_REMOVEDIR) 421 rflags |= P9_DOTL_AT_REMOVEDIR; 422 423 return rflags; 424} 425 426/** 427 * v9fs_dec_count - helper functon to drop i_nlink. 428 * 429 * If a directory had nlink <= 2 (including . and ..), then we should not drop 430 * the link count, which indicates the underlying exported fs doesn't maintain 431 * nlink accurately. e.g. 432 * - overlayfs sets nlink to 1 for merged dir 433 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more 434 * than EXT4_LINK_MAX (65000) links. 435 * 436 * @inode: inode whose nlink is being dropped 437 */ 438static void v9fs_dec_count(struct inode *inode) 439{ 440 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 441 drop_nlink(inode); 442} 443 444/** 445 * v9fs_remove - helper function to remove files and directories 446 * @dir: directory inode that is being deleted 447 * @dentry: dentry that is being deleted 448 * @flags: removing a directory 449 * 450 */ 451 452static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) 453{ 454 struct inode *inode; 455 int retval = -EOPNOTSUPP; 456 struct p9_fid *v9fid, *dfid; 457 struct v9fs_session_info *v9ses; 458 459 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n", 460 dir, dentry, flags); 461 462 v9ses = v9fs_inode2v9ses(dir); 463 inode = d_inode(dentry); 464 dfid = v9fs_parent_fid(dentry); 465 if (IS_ERR(dfid)) { 466 retval = PTR_ERR(dfid); 467 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval); 468 return retval; 469 } 470 if (v9fs_proto_dotl(v9ses)) 471 retval = p9_client_unlinkat(dfid, dentry->d_name.name, 472 v9fs_at_to_dotl_flags(flags)); 473 p9_fid_put(dfid); 474 if (retval == -EOPNOTSUPP) { 475 /* Try the one based on path */ 476 v9fid = v9fs_fid_clone(dentry); 477 if (IS_ERR(v9fid)) 478 return PTR_ERR(v9fid); 479 retval = p9_client_remove(v9fid); 480 } 481 if (!retval) { 482 /* 483 * directories on unlink should have zero 484 * link count 485 */ 486 if (flags & AT_REMOVEDIR) { 487 clear_nlink(inode); 488 v9fs_dec_count(dir); 489 } else 490 v9fs_dec_count(inode); 491 492 v9fs_invalidate_inode_attr(inode); 493 v9fs_invalidate_inode_attr(dir); 494 495 /* invalidate all fids associated with dentry */ 496 /* NOTE: This will not include open fids */ 497 dentry->d_op->d_release(dentry); 498 } 499 return retval; 500} 501 502/** 503 * v9fs_create - Create a file 504 * @v9ses: session information 505 * @dir: directory that dentry is being created in 506 * @dentry: dentry that is being created 507 * @extension: 9p2000.u extension string to support devices, etc. 508 * @perm: create permissions 509 * @mode: open mode 510 * 511 */ 512static struct p9_fid * 513v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 514 struct dentry *dentry, char *extension, u32 perm, u8 mode) 515{ 516 int err; 517 const unsigned char *name; 518 struct p9_fid *dfid, *ofid = NULL, *fid = NULL; 519 struct inode *inode; 520 521 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 522 523 name = dentry->d_name.name; 524 dfid = v9fs_parent_fid(dentry); 525 if (IS_ERR(dfid)) { 526 err = PTR_ERR(dfid); 527 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err); 528 return ERR_PTR(err); 529 } 530 531 /* clone a fid to use for creation */ 532 ofid = clone_fid(dfid); 533 if (IS_ERR(ofid)) { 534 err = PTR_ERR(ofid); 535 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); 536 goto error; 537 } 538 539 err = p9_client_fcreate(ofid, name, perm, mode, extension); 540 if (err < 0) { 541 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); 542 goto error; 543 } 544 545 if (!(perm & P9_DMLINK)) { 546 /* now walk from the parent so we can get unopened fid */ 547 fid = p9_client_walk(dfid, 1, &name, 1); 548 if (IS_ERR(fid)) { 549 err = PTR_ERR(fid); 550 p9_debug(P9_DEBUG_VFS, 551 "p9_client_walk failed %d\n", err); 552 goto error; 553 } 554 /* 555 * instantiate inode and assign the unopened fid to the dentry 556 */ 557 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); 558 if (IS_ERR(inode)) { 559 err = PTR_ERR(inode); 560 p9_debug(P9_DEBUG_VFS, 561 "inode creation failed %d\n", err); 562 goto error; 563 } 564 v9fs_fid_add(dentry, &fid); 565 d_instantiate(dentry, inode); 566 } 567 p9_fid_put(dfid); 568 return ofid; 569error: 570 p9_fid_put(dfid); 571 p9_fid_put(ofid); 572 p9_fid_put(fid); 573 return ERR_PTR(err); 574} 575 576/** 577 * v9fs_vfs_create - VFS hook to create a regular file 578 * @idmap: idmap of the mount 579 * @dir: The parent directory 580 * @dentry: The name of file to be created 581 * @mode: The UNIX file mode to set 582 * @excl: True if the file must not yet exist 583 * 584 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called 585 * for mknod(2). 586 * 587 */ 588 589static int 590v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir, 591 struct dentry *dentry, umode_t mode, bool excl) 592{ 593 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 594 u32 perm = unixmode2p9mode(v9ses, mode); 595 struct p9_fid *fid; 596 597 /* P9_OEXCL? */ 598 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR); 599 if (IS_ERR(fid)) 600 return PTR_ERR(fid); 601 602 v9fs_invalidate_inode_attr(dir); 603 p9_fid_put(fid); 604 605 return 0; 606} 607 608/** 609 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory 610 * @idmap: idmap of the mount 611 * @dir: inode that is being unlinked 612 * @dentry: dentry that is being unlinked 613 * @mode: mode for new directory 614 * 615 */ 616 617static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir, 618 struct dentry *dentry, umode_t mode) 619{ 620 int err; 621 u32 perm; 622 struct p9_fid *fid; 623 struct v9fs_session_info *v9ses; 624 625 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); 626 err = 0; 627 v9ses = v9fs_inode2v9ses(dir); 628 perm = unixmode2p9mode(v9ses, mode | S_IFDIR); 629 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD); 630 if (IS_ERR(fid)) { 631 err = PTR_ERR(fid); 632 fid = NULL; 633 } else { 634 inc_nlink(dir); 635 v9fs_invalidate_inode_attr(dir); 636 } 637 638 if (fid) 639 p9_fid_put(fid); 640 641 return err; 642} 643 644/** 645 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode 646 * @dir: inode that is being walked from 647 * @dentry: dentry that is being walked to? 648 * @flags: lookup flags (unused) 649 * 650 */ 651 652struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, 653 unsigned int flags) 654{ 655 struct dentry *res; 656 struct v9fs_session_info *v9ses; 657 struct p9_fid *dfid, *fid; 658 struct inode *inode; 659 const unsigned char *name; 660 661 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n", 662 dir, dentry, dentry, flags); 663 664 if (dentry->d_name.len > NAME_MAX) 665 return ERR_PTR(-ENAMETOOLONG); 666 667 v9ses = v9fs_inode2v9ses(dir); 668 /* We can walk d_parent because we hold the dir->i_mutex */ 669 dfid = v9fs_parent_fid(dentry); 670 if (IS_ERR(dfid)) 671 return ERR_CAST(dfid); 672 673 /* 674 * Make sure we don't use a wrong inode due to parallel 675 * unlink. For cached mode create calls request for new 676 * inode. But with cache disabled, lookup should do this. 677 */ 678 name = dentry->d_name.name; 679 fid = p9_client_walk(dfid, 1, &name, 1); 680 p9_fid_put(dfid); 681 if (fid == ERR_PTR(-ENOENT)) 682 inode = NULL; 683 else if (IS_ERR(fid)) 684 inode = ERR_CAST(fid); 685 else 686 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); 687 /* 688 * If we had a rename on the server and a parallel lookup 689 * for the new name, then make sure we instantiate with 690 * the new name. ie look up for a/b, while on server somebody 691 * moved b under k and client parallely did a lookup for 692 * k/b. 693 */ 694 res = d_splice_alias(inode, dentry); 695 if (!IS_ERR(fid)) { 696 if (!res) 697 v9fs_fid_add(dentry, &fid); 698 else if (!IS_ERR(res)) 699 v9fs_fid_add(res, &fid); 700 else 701 p9_fid_put(fid); 702 } 703 return res; 704} 705 706static int 707v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, 708 struct file *file, unsigned int flags, umode_t mode) 709{ 710 int err; 711 u32 perm; 712 struct v9fs_inode __maybe_unused *v9inode; 713 struct v9fs_session_info *v9ses; 714 struct p9_fid *fid; 715 struct dentry *res = NULL; 716 struct inode *inode; 717 int p9_omode; 718 719 if (d_in_lookup(dentry)) { 720 res = v9fs_vfs_lookup(dir, dentry, 0); 721 if (IS_ERR(res)) 722 return PTR_ERR(res); 723 724 if (res) 725 dentry = res; 726 } 727 728 /* Only creates */ 729 if (!(flags & O_CREAT) || d_really_is_positive(dentry)) 730 return finish_no_open(file, res); 731 732 v9ses = v9fs_inode2v9ses(dir); 733 perm = unixmode2p9mode(v9ses, mode); 734 p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses)); 735 736 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) { 737 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR; 738 p9_debug(P9_DEBUG_CACHE, 739 "write-only file with writeback enabled, creating w/ O_RDWR\n"); 740 } 741 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode); 742 if (IS_ERR(fid)) { 743 err = PTR_ERR(fid); 744 goto error; 745 } 746 747 v9fs_invalidate_inode_attr(dir); 748 inode = d_inode(dentry); 749 v9inode = V9FS_I(inode); 750 err = finish_open(file, dentry, generic_file_open); 751 if (err) 752 goto error; 753 754 file->private_data = fid; 755#ifdef CONFIG_9P_FSCACHE 756 if (v9ses->cache & CACHE_FSCACHE) 757 fscache_use_cookie(v9fs_inode_cookie(v9inode), 758 file->f_mode & FMODE_WRITE); 759#endif 760 761 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags); 762 v9fs_open_fid_add(inode, &fid); 763 764 file->f_mode |= FMODE_CREATED; 765out: 766 dput(res); 767 return err; 768 769error: 770 p9_fid_put(fid); 771 goto out; 772} 773 774/** 775 * v9fs_vfs_unlink - VFS unlink hook to delete an inode 776 * @i: inode that is being unlinked 777 * @d: dentry that is being unlinked 778 * 779 */ 780 781int v9fs_vfs_unlink(struct inode *i, struct dentry *d) 782{ 783 return v9fs_remove(i, d, 0); 784} 785 786/** 787 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory 788 * @i: inode that is being unlinked 789 * @d: dentry that is being unlinked 790 * 791 */ 792 793int v9fs_vfs_rmdir(struct inode *i, struct dentry *d) 794{ 795 return v9fs_remove(i, d, AT_REMOVEDIR); 796} 797 798/** 799 * v9fs_vfs_rename - VFS hook to rename an inode 800 * @idmap: The idmap of the mount 801 * @old_dir: old dir inode 802 * @old_dentry: old dentry 803 * @new_dir: new dir inode 804 * @new_dentry: new dentry 805 * @flags: RENAME_* flags 806 * 807 */ 808 809int 810v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, 811 struct dentry *old_dentry, struct inode *new_dir, 812 struct dentry *new_dentry, unsigned int flags) 813{ 814 int retval; 815 struct inode *old_inode; 816 struct inode *new_inode; 817 struct v9fs_session_info *v9ses; 818 struct p9_fid *oldfid = NULL, *dfid = NULL; 819 struct p9_fid *olddirfid = NULL; 820 struct p9_fid *newdirfid = NULL; 821 struct p9_wstat wstat; 822 823 if (flags) 824 return -EINVAL; 825 826 p9_debug(P9_DEBUG_VFS, "\n"); 827 old_inode = d_inode(old_dentry); 828 new_inode = d_inode(new_dentry); 829 v9ses = v9fs_inode2v9ses(old_inode); 830 oldfid = v9fs_fid_lookup(old_dentry); 831 if (IS_ERR(oldfid)) 832 return PTR_ERR(oldfid); 833 834 dfid = v9fs_parent_fid(old_dentry); 835 olddirfid = clone_fid(dfid); 836 p9_fid_put(dfid); 837 dfid = NULL; 838 839 if (IS_ERR(olddirfid)) { 840 retval = PTR_ERR(olddirfid); 841 goto error; 842 } 843 844 dfid = v9fs_parent_fid(new_dentry); 845 newdirfid = clone_fid(dfid); 846 p9_fid_put(dfid); 847 dfid = NULL; 848 849 if (IS_ERR(newdirfid)) { 850 retval = PTR_ERR(newdirfid); 851 goto error; 852 } 853 854 down_write(&v9ses->rename_sem); 855 if (v9fs_proto_dotl(v9ses)) { 856 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name, 857 newdirfid, new_dentry->d_name.name); 858 if (retval == -EOPNOTSUPP) 859 retval = p9_client_rename(oldfid, newdirfid, 860 new_dentry->d_name.name); 861 if (retval != -EOPNOTSUPP) 862 goto error_locked; 863 } 864 if (old_dentry->d_parent != new_dentry->d_parent) { 865 /* 866 * 9P .u can only handle file rename in the same directory 867 */ 868 869 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n"); 870 retval = -EXDEV; 871 goto error_locked; 872 } 873 v9fs_blank_wstat(&wstat); 874 wstat.muid = v9ses->uname; 875 wstat.name = new_dentry->d_name.name; 876 retval = p9_client_wstat(oldfid, &wstat); 877 878error_locked: 879 if (!retval) { 880 if (new_inode) { 881 if (S_ISDIR(new_inode->i_mode)) 882 clear_nlink(new_inode); 883 else 884 v9fs_dec_count(new_inode); 885 } 886 if (S_ISDIR(old_inode->i_mode)) { 887 if (!new_inode) 888 inc_nlink(new_dir); 889 v9fs_dec_count(old_dir); 890 } 891 v9fs_invalidate_inode_attr(old_inode); 892 v9fs_invalidate_inode_attr(old_dir); 893 v9fs_invalidate_inode_attr(new_dir); 894 895 /* successful rename */ 896 d_move(old_dentry, new_dentry); 897 } 898 up_write(&v9ses->rename_sem); 899 900error: 901 p9_fid_put(newdirfid); 902 p9_fid_put(olddirfid); 903 p9_fid_put(oldfid); 904 return retval; 905} 906 907/** 908 * v9fs_vfs_getattr - retrieve file metadata 909 * @idmap: idmap of the mount 910 * @path: Object to query 911 * @stat: metadata structure to populate 912 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests 913 * @flags: AT_STATX_xxx setting 914 * 915 */ 916 917static int 918v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path, 919 struct kstat *stat, u32 request_mask, unsigned int flags) 920{ 921 struct dentry *dentry = path->dentry; 922 struct inode *inode = d_inode(dentry); 923 struct v9fs_session_info *v9ses; 924 struct p9_fid *fid; 925 struct p9_wstat *st; 926 927 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry); 928 v9ses = v9fs_dentry2v9ses(dentry); 929 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) { 930 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 931 return 0; 932 } else if (v9ses->cache & CACHE_WRITEBACK) { 933 if (S_ISREG(inode->i_mode)) { 934 int retval = filemap_fdatawrite(inode->i_mapping); 935 936 if (retval) 937 p9_debug(P9_DEBUG_ERROR, 938 "flushing writeback during getattr returned %d\n", retval); 939 } 940 } 941 fid = v9fs_fid_lookup(dentry); 942 if (IS_ERR(fid)) 943 return PTR_ERR(fid); 944 945 st = p9_client_stat(fid); 946 p9_fid_put(fid); 947 if (IS_ERR(st)) 948 return PTR_ERR(st); 949 950 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0); 951 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat); 952 953 p9stat_free(st); 954 kfree(st); 955 return 0; 956} 957 958/** 959 * v9fs_vfs_setattr - set file metadata 960 * @idmap: idmap of the mount 961 * @dentry: file whose metadata to set 962 * @iattr: metadata assignment structure 963 * 964 */ 965 966static int v9fs_vfs_setattr(struct mnt_idmap *idmap, 967 struct dentry *dentry, struct iattr *iattr) 968{ 969 int retval, use_dentry = 0; 970 struct inode *inode = d_inode(dentry); 971 struct v9fs_session_info *v9ses; 972 struct p9_fid *fid = NULL; 973 struct p9_wstat wstat; 974 975 p9_debug(P9_DEBUG_VFS, "\n"); 976 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 977 if (retval) 978 return retval; 979 980 v9ses = v9fs_dentry2v9ses(dentry); 981 if (iattr->ia_valid & ATTR_FILE) { 982 fid = iattr->ia_file->private_data; 983 WARN_ON(!fid); 984 } 985 if (!fid) { 986 fid = v9fs_fid_lookup(dentry); 987 use_dentry = 1; 988 } 989 if (IS_ERR(fid)) 990 return PTR_ERR(fid); 991 992 v9fs_blank_wstat(&wstat); 993 if (iattr->ia_valid & ATTR_MODE) 994 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode); 995 996 if (iattr->ia_valid & ATTR_MTIME) 997 wstat.mtime = iattr->ia_mtime.tv_sec; 998 999 if (iattr->ia_valid & ATTR_ATIME) 1000 wstat.atime = iattr->ia_atime.tv_sec; 1001 1002 if (iattr->ia_valid & ATTR_SIZE) 1003 wstat.length = iattr->ia_size; 1004 1005 if (v9fs_proto_dotu(v9ses)) { 1006 if (iattr->ia_valid & ATTR_UID) 1007 wstat.n_uid = iattr->ia_uid; 1008 1009 if (iattr->ia_valid & ATTR_GID) 1010 wstat.n_gid = iattr->ia_gid; 1011 } 1012 1013 /* Write all dirty data */ 1014 if (d_is_reg(dentry)) { 1015 retval = filemap_fdatawrite(inode->i_mapping); 1016 if (retval) 1017 p9_debug(P9_DEBUG_ERROR, 1018 "flushing writeback during setattr returned %d\n", retval); 1019 } 1020 1021 retval = p9_client_wstat(fid, &wstat); 1022 1023 if (use_dentry) 1024 p9_fid_put(fid); 1025 1026 if (retval < 0) 1027 return retval; 1028 1029 if ((iattr->ia_valid & ATTR_SIZE) && 1030 iattr->ia_size != i_size_read(inode)) { 1031 truncate_setsize(inode, iattr->ia_size); 1032 netfs_resize_file(netfs_inode(inode), iattr->ia_size, true); 1033 1034#ifdef CONFIG_9P_FSCACHE 1035 if (v9ses->cache & CACHE_FSCACHE) { 1036 struct v9fs_inode *v9inode = V9FS_I(inode); 1037 1038 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size); 1039 } 1040#endif 1041 } 1042 1043 v9fs_invalidate_inode_attr(inode); 1044 1045 setattr_copy(&nop_mnt_idmap, inode, iattr); 1046 mark_inode_dirty(inode); 1047 return 0; 1048} 1049 1050/** 1051 * v9fs_stat2inode - populate an inode structure with mistat info 1052 * @stat: Plan 9 metadata (mistat) structure 1053 * @inode: inode to populate 1054 * @sb: superblock of filesystem 1055 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE) 1056 * 1057 */ 1058 1059void 1060v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, 1061 struct super_block *sb, unsigned int flags) 1062{ 1063 umode_t mode; 1064 struct v9fs_session_info *v9ses = sb->s_fs_info; 1065 struct v9fs_inode *v9inode = V9FS_I(inode); 1066 1067 inode_set_atime(inode, stat->atime, 0); 1068 inode_set_mtime(inode, stat->mtime, 0); 1069 inode_set_ctime(inode, stat->mtime, 0); 1070 1071 inode->i_uid = v9ses->dfltuid; 1072 inode->i_gid = v9ses->dfltgid; 1073 1074 if (v9fs_proto_dotu(v9ses)) { 1075 inode->i_uid = stat->n_uid; 1076 inode->i_gid = stat->n_gid; 1077 } 1078 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) { 1079 if (v9fs_proto_dotu(v9ses)) { 1080 unsigned int i_nlink; 1081 /* 1082 * Hadlink support got added later to the .u extension. 1083 * So there can be a server out there that doesn't 1084 * support this even with .u extension. That would 1085 * just leave us with stat->extension being an empty 1086 * string, though. 1087 */ 1088 /* HARDLINKCOUNT %u */ 1089 if (sscanf(stat->extension, 1090 " HARDLINKCOUNT %u", &i_nlink) == 1) 1091 set_nlink(inode, i_nlink); 1092 } 1093 } 1094 mode = p9mode2perm(v9ses, stat); 1095 mode |= inode->i_mode & ~S_IALLUGO; 1096 inode->i_mode = mode; 1097 1098 v9inode->netfs.remote_i_size = stat->length; 1099 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) 1100 v9fs_i_size_write(inode, stat->length); 1101 /* not real number of blocks, but 512 byte ones ... */ 1102 inode->i_blocks = (stat->length + 512 - 1) >> 9; 1103 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR; 1104} 1105 1106/** 1107 * v9fs_vfs_get_link - follow a symlink path 1108 * @dentry: dentry for symlink 1109 * @inode: inode for symlink 1110 * @done: delayed call for when we are done with the return value 1111 */ 1112 1113static const char *v9fs_vfs_get_link(struct dentry *dentry, 1114 struct inode *inode, 1115 struct delayed_call *done) 1116{ 1117 struct v9fs_session_info *v9ses; 1118 struct p9_fid *fid; 1119 struct p9_wstat *st; 1120 char *res; 1121 1122 if (!dentry) 1123 return ERR_PTR(-ECHILD); 1124 1125 v9ses = v9fs_dentry2v9ses(dentry); 1126 if (!v9fs_proto_dotu(v9ses)) 1127 return ERR_PTR(-EBADF); 1128 1129 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); 1130 fid = v9fs_fid_lookup(dentry); 1131 1132 if (IS_ERR(fid)) 1133 return ERR_CAST(fid); 1134 1135 st = p9_client_stat(fid); 1136 p9_fid_put(fid); 1137 if (IS_ERR(st)) 1138 return ERR_CAST(st); 1139 1140 if (!(st->mode & P9_DMSYMLINK)) { 1141 p9stat_free(st); 1142 kfree(st); 1143 return ERR_PTR(-EINVAL); 1144 } 1145 res = st->extension; 1146 st->extension = NULL; 1147 if (strlen(res) >= PATH_MAX) 1148 res[PATH_MAX - 1] = '\0'; 1149 1150 p9stat_free(st); 1151 kfree(st); 1152 set_delayed_call(done, kfree_link, res); 1153 return res; 1154} 1155 1156/** 1157 * v9fs_vfs_mkspecial - create a special file 1158 * @dir: inode to create special file in 1159 * @dentry: dentry to create 1160 * @perm: mode to create special file 1161 * @extension: 9p2000.u format extension string representing special file 1162 * 1163 */ 1164 1165static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, 1166 u32 perm, const char *extension) 1167{ 1168 struct p9_fid *fid; 1169 struct v9fs_session_info *v9ses; 1170 1171 v9ses = v9fs_inode2v9ses(dir); 1172 if (!v9fs_proto_dotu(v9ses)) { 1173 p9_debug(P9_DEBUG_ERROR, "not extended\n"); 1174 return -EPERM; 1175 } 1176 1177 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm, 1178 P9_OREAD); 1179 if (IS_ERR(fid)) 1180 return PTR_ERR(fid); 1181 1182 v9fs_invalidate_inode_attr(dir); 1183 p9_fid_put(fid); 1184 return 0; 1185} 1186 1187/** 1188 * v9fs_vfs_symlink - helper function to create symlinks 1189 * @idmap: idmap of the mount 1190 * @dir: directory inode containing symlink 1191 * @dentry: dentry for symlink 1192 * @symname: symlink data 1193 * 1194 * See Also: 9P2000.u RFC for more information 1195 * 1196 */ 1197 1198static int 1199v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir, 1200 struct dentry *dentry, const char *symname) 1201{ 1202 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n", 1203 dir->i_ino, dentry, symname); 1204 1205 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname); 1206} 1207 1208#define U32_MAX_DIGITS 10 1209 1210/** 1211 * v9fs_vfs_link - create a hardlink 1212 * @old_dentry: dentry for file to link to 1213 * @dir: inode destination for new link 1214 * @dentry: dentry for link 1215 * 1216 */ 1217 1218static int 1219v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir, 1220 struct dentry *dentry) 1221{ 1222 int retval; 1223 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */ 1224 struct p9_fid *oldfid; 1225 1226 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n", 1227 dir->i_ino, dentry, old_dentry); 1228 1229 oldfid = v9fs_fid_clone(old_dentry); 1230 if (IS_ERR(oldfid)) 1231 return PTR_ERR(oldfid); 1232 1233 sprintf(name, "%d\n", oldfid->fid); 1234 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name); 1235 if (!retval) { 1236 v9fs_refresh_inode(oldfid, d_inode(old_dentry)); 1237 v9fs_invalidate_inode_attr(dir); 1238 } 1239 p9_fid_put(oldfid); 1240 return retval; 1241} 1242 1243/** 1244 * v9fs_vfs_mknod - create a special file 1245 * @idmap: idmap of the mount 1246 * @dir: inode destination for new link 1247 * @dentry: dentry for file 1248 * @mode: mode for creation 1249 * @rdev: device associated with special file 1250 * 1251 */ 1252 1253static int 1254v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, 1255 struct dentry *dentry, umode_t mode, dev_t rdev) 1256{ 1257 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); 1258 int retval; 1259 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1]; 1260 u32 perm; 1261 1262 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n", 1263 dir->i_ino, dentry, mode, 1264 MAJOR(rdev), MINOR(rdev)); 1265 1266 /* build extension */ 1267 if (S_ISBLK(mode)) 1268 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev)); 1269 else if (S_ISCHR(mode)) 1270 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev)); 1271 else 1272 *name = 0; 1273 1274 perm = unixmode2p9mode(v9ses, mode); 1275 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name); 1276 1277 return retval; 1278} 1279 1280int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) 1281{ 1282 int umode; 1283 dev_t rdev; 1284 struct p9_wstat *st; 1285 struct v9fs_session_info *v9ses; 1286 unsigned int flags; 1287 1288 v9ses = v9fs_inode2v9ses(inode); 1289 st = p9_client_stat(fid); 1290 if (IS_ERR(st)) 1291 return PTR_ERR(st); 1292 /* 1293 * Don't update inode if the file type is different 1294 */ 1295 umode = p9mode2unixmode(v9ses, st, &rdev); 1296 if (inode_wrong_type(inode, umode)) 1297 goto out; 1298 1299 /* 1300 * We don't want to refresh inode->i_size, 1301 * because we may have cached data 1302 */ 1303 flags = (v9ses->cache & CACHE_LOOSE) ? 1304 V9FS_STAT2INODE_KEEP_ISIZE : 0; 1305 v9fs_stat2inode(st, inode, inode->i_sb, flags); 1306out: 1307 p9stat_free(st); 1308 kfree(st); 1309 return 0; 1310} 1311 1312static const struct inode_operations v9fs_dir_inode_operations_dotu = { 1313 .create = v9fs_vfs_create, 1314 .lookup = v9fs_vfs_lookup, 1315 .atomic_open = v9fs_vfs_atomic_open, 1316 .symlink = v9fs_vfs_symlink, 1317 .link = v9fs_vfs_link, 1318 .unlink = v9fs_vfs_unlink, 1319 .mkdir = v9fs_vfs_mkdir, 1320 .rmdir = v9fs_vfs_rmdir, 1321 .mknod = v9fs_vfs_mknod, 1322 .rename = v9fs_vfs_rename, 1323 .getattr = v9fs_vfs_getattr, 1324 .setattr = v9fs_vfs_setattr, 1325}; 1326 1327static const struct inode_operations v9fs_dir_inode_operations = { 1328 .create = v9fs_vfs_create, 1329 .lookup = v9fs_vfs_lookup, 1330 .atomic_open = v9fs_vfs_atomic_open, 1331 .unlink = v9fs_vfs_unlink, 1332 .mkdir = v9fs_vfs_mkdir, 1333 .rmdir = v9fs_vfs_rmdir, 1334 .mknod = v9fs_vfs_mknod, 1335 .rename = v9fs_vfs_rename, 1336 .getattr = v9fs_vfs_getattr, 1337 .setattr = v9fs_vfs_setattr, 1338}; 1339 1340static const struct inode_operations v9fs_file_inode_operations = { 1341 .getattr = v9fs_vfs_getattr, 1342 .setattr = v9fs_vfs_setattr, 1343}; 1344 1345static const struct inode_operations v9fs_symlink_inode_operations = { 1346 .get_link = v9fs_vfs_get_link, 1347 .getattr = v9fs_vfs_getattr, 1348 .setattr = v9fs_vfs_setattr, 1349}; 1350 1351