1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/ceph/ceph_debug.h> 3 4 #include <linux/exportfs.h> 5 #include <linux/slab.h> 6 #include <asm/unaligned.h> 7 8 #include "super.h" 9 #include "mds_client.h" 10 #include "crypto.h" 11 12 /* 13 * Basic fh 14 */ 15 struct ceph_nfs_fh { 16 u64 ino; 17 } __attribute__ ((packed)); 18 19 /* 20 * Larger fh that includes parent ino. 21 */ 22 struct ceph_nfs_confh { 23 u64 ino, parent_ino; 24 } __attribute__ ((packed)); 25 26 /* 27 * fh for snapped inode 28 */ 29 struct ceph_nfs_snapfh { 30 u64 ino; 31 u64 snapid; 32 u64 parent_ino; 33 u32 hash; 34 } __attribute__ ((packed)); 35 36 static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len, 37 struct inode *parent_inode) 38 { 39 struct ceph_client *cl = ceph_inode_to_client(inode); 40 static const int snap_handle_length = 41 sizeof(struct ceph_nfs_snapfh) >> 2; 42 struct ceph_nfs_snapfh *sfh = (void *)rawfh; 43 u64 snapid = ceph_snap(inode); 44 int ret; 45 bool no_parent = true; 46 47 if (*max_len < snap_handle_length) { 48 *max_len = snap_handle_length; 49 ret = FILEID_INVALID; 50 goto out; 51 } 52 53 ret = -EINVAL; 54 if (snapid != CEPH_SNAPDIR) { 55 struct inode *dir; 56 struct dentry *dentry = d_find_alias(inode); 57 if (!dentry) 58 goto out; 59 60 rcu_read_lock(); 61 dir = d_inode_rcu(dentry->d_parent); 62 if (ceph_snap(dir) != CEPH_SNAPDIR) { 63 sfh->parent_ino = ceph_ino(dir); 64 sfh->hash = ceph_dentry_hash(dir, dentry); 65 no_parent = false; 66 } 67 rcu_read_unlock(); 68 dput(dentry); 69 } 70 71 if (no_parent) { 72 if (!S_ISDIR(inode->i_mode)) 73 goto out; 74 sfh->parent_ino = sfh->ino; 75 sfh->hash = 0; 76 } 77 sfh->ino = ceph_ino(inode); 78 sfh->snapid = snapid; 79 80 *max_len = snap_handle_length; 81 ret = FILEID_BTRFS_WITH_PARENT; 82 out: 83 doutc(cl, "%p %llx.%llx ret=%d\n", inode, ceph_vinop(inode), ret); 84 return ret; 85 } 86 87 static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len, 88 struct inode *parent_inode) 89 { 90 struct ceph_client *cl = ceph_inode_to_client(inode); 91 static const int handle_length = 92 sizeof(struct ceph_nfs_fh) >> 2; 93 static const int connected_handle_length = 94 sizeof(struct ceph_nfs_confh) >> 2; 95 int type; 96 97 if (ceph_snap(inode) != CEPH_NOSNAP) 98 return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode); 99 100 if (parent_inode && (*max_len < connected_handle_length)) { 101 *max_len = connected_handle_length; 102 return FILEID_INVALID; 103 } else if (*max_len < handle_length) { 104 *max_len = handle_length; 105 return FILEID_INVALID; 106 } 107 108 if (parent_inode) { 109 struct ceph_nfs_confh *cfh = (void *)rawfh; 110 doutc(cl, "%p %llx.%llx with parent %p %llx.%llx\n", inode, 111 ceph_vinop(inode), parent_inode, ceph_vinop(parent_inode)); 112 cfh->ino = ceph_ino(inode); 113 cfh->parent_ino = ceph_ino(parent_inode); 114 *max_len = connected_handle_length; 115 type = FILEID_INO32_GEN_PARENT; 116 } else { 117 struct ceph_nfs_fh *fh = (void *)rawfh; 118 doutc(cl, "%p %llx.%llx\n", inode, ceph_vinop(inode)); 119 fh->ino = ceph_ino(inode); 120 *max_len = handle_length; 121 type = FILEID_INO32_GEN; 122 } 123 return type; 124 } 125 126 static struct inode *__lookup_inode(struct super_block *sb, u64 ino) 127 { 128 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc; 129 struct inode *inode; 130 struct ceph_vino vino; 131 int err; 132 133 vino.ino = ino; 134 vino.snap = CEPH_NOSNAP; 135 136 if (ceph_vino_is_reserved(vino)) 137 return ERR_PTR(-ESTALE); 138 139 inode = ceph_find_inode(sb, vino); 140 if (!inode) { 141 struct ceph_mds_request *req; 142 int mask; 143 144 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 145 USE_ANY_MDS); 146 if (IS_ERR(req)) 147 return ERR_CAST(req); 148 149 mask = CEPH_STAT_CAP_INODE; 150 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 151 mask |= CEPH_CAP_XATTR_SHARED; 152 req->r_args.lookupino.mask = cpu_to_le32(mask); 153 154 req->r_ino1 = vino; 155 req->r_num_caps = 1; 156 err = ceph_mdsc_do_request(mdsc, NULL, req); 157 inode = req->r_target_inode; 158 if (inode) 159 ihold(inode); 160 ceph_mdsc_put_request(req); 161 if (!inode) 162 return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE); 163 } else { 164 if (ceph_inode_is_shutdown(inode)) { 165 iput(inode); 166 return ERR_PTR(-ESTALE); 167 } 168 } 169 return inode; 170 } 171 172 struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino) 173 { 174 struct inode *inode = __lookup_inode(sb, ino); 175 if (IS_ERR(inode)) 176 return inode; 177 if (inode->i_nlink == 0) { 178 iput(inode); 179 return ERR_PTR(-ESTALE); 180 } 181 return inode; 182 } 183 184 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) 185 { 186 struct inode *inode = __lookup_inode(sb, ino); 187 struct ceph_inode_info *ci = ceph_inode(inode); 188 int err; 189 190 if (IS_ERR(inode)) 191 return ERR_CAST(inode); 192 /* We need LINK caps to reliably check i_nlink */ 193 err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); 194 if (err) { 195 iput(inode); 196 return ERR_PTR(err); 197 } 198 /* -ESTALE if inode as been unlinked and no file is open */ 199 if ((inode->i_nlink == 0) && !__ceph_is_file_opened(ci)) { 200 iput(inode); 201 return ERR_PTR(-ESTALE); 202 } 203 return d_obtain_alias(inode); 204 } 205 206 static struct dentry *__snapfh_to_dentry(struct super_block *sb, 207 struct ceph_nfs_snapfh *sfh, 208 bool want_parent) 209 { 210 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc; 211 struct ceph_client *cl = mdsc->fsc->client; 212 struct ceph_mds_request *req; 213 struct inode *inode; 214 struct ceph_vino vino; 215 int mask; 216 int err; 217 bool unlinked = false; 218 219 if (want_parent) { 220 vino.ino = sfh->parent_ino; 221 if (sfh->snapid == CEPH_SNAPDIR) 222 vino.snap = CEPH_NOSNAP; 223 else if (sfh->ino == sfh->parent_ino) 224 vino.snap = CEPH_SNAPDIR; 225 else 226 vino.snap = sfh->snapid; 227 } else { 228 vino.ino = sfh->ino; 229 vino.snap = sfh->snapid; 230 } 231 232 if (ceph_vino_is_reserved(vino)) 233 return ERR_PTR(-ESTALE); 234 235 inode = ceph_find_inode(sb, vino); 236 if (inode) { 237 if (ceph_inode_is_shutdown(inode)) { 238 iput(inode); 239 return ERR_PTR(-ESTALE); 240 } 241 return d_obtain_alias(inode); 242 } 243 244 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 245 USE_ANY_MDS); 246 if (IS_ERR(req)) 247 return ERR_CAST(req); 248 249 mask = CEPH_STAT_CAP_INODE; 250 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 251 mask |= CEPH_CAP_XATTR_SHARED; 252 req->r_args.lookupino.mask = cpu_to_le32(mask); 253 if (vino.snap < CEPH_NOSNAP) { 254 req->r_args.lookupino.snapid = cpu_to_le64(vino.snap); 255 if (!want_parent && sfh->ino != sfh->parent_ino) { 256 req->r_args.lookupino.parent = 257 cpu_to_le64(sfh->parent_ino); 258 req->r_args.lookupino.hash = 259 cpu_to_le32(sfh->hash); 260 } 261 } 262 263 req->r_ino1 = vino; 264 req->r_num_caps = 1; 265 err = ceph_mdsc_do_request(mdsc, NULL, req); 266 inode = req->r_target_inode; 267 if (inode) { 268 if (vino.snap == CEPH_SNAPDIR) { 269 if (inode->i_nlink == 0) 270 unlinked = true; 271 inode = ceph_get_snapdir(inode); 272 } else if (ceph_snap(inode) == vino.snap) { 273 ihold(inode); 274 } else { 275 /* mds does not support lookup snapped inode */ 276 inode = ERR_PTR(-EOPNOTSUPP); 277 } 278 } else { 279 inode = ERR_PTR(-ESTALE); 280 } 281 ceph_mdsc_put_request(req); 282 283 if (want_parent) { 284 doutc(cl, "%llx.%llx\n err=%d\n", vino.ino, vino.snap, err); 285 } else { 286 doutc(cl, "%llx.%llx parent %llx hash %x err=%d", vino.ino, 287 vino.snap, sfh->parent_ino, sfh->hash, err); 288 } 289 /* see comments in ceph_get_parent() */ 290 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode); 291 } 292 293 /* 294 * convert regular fh to dentry 295 */ 296 static struct dentry *ceph_fh_to_dentry(struct super_block *sb, 297 struct fid *fid, 298 int fh_len, int fh_type) 299 { 300 struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb); 301 struct ceph_nfs_fh *fh = (void *)fid->raw; 302 303 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 304 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 305 return __snapfh_to_dentry(sb, sfh, false); 306 } 307 308 if (fh_type != FILEID_INO32_GEN && 309 fh_type != FILEID_INO32_GEN_PARENT) 310 return NULL; 311 if (fh_len < sizeof(*fh) / 4) 312 return NULL; 313 314 doutc(fsc->client, "%llx\n", fh->ino); 315 return __fh_to_dentry(sb, fh->ino); 316 } 317 318 static struct dentry *__get_parent(struct super_block *sb, 319 struct dentry *child, u64 ino) 320 { 321 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc; 322 struct ceph_mds_request *req; 323 struct inode *inode; 324 int mask; 325 int err; 326 327 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, 328 USE_ANY_MDS); 329 if (IS_ERR(req)) 330 return ERR_CAST(req); 331 332 if (child) { 333 req->r_inode = d_inode(child); 334 ihold(d_inode(child)); 335 } else { 336 req->r_ino1 = (struct ceph_vino) { 337 .ino = ino, 338 .snap = CEPH_NOSNAP, 339 }; 340 } 341 342 mask = CEPH_STAT_CAP_INODE; 343 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 344 mask |= CEPH_CAP_XATTR_SHARED; 345 req->r_args.getattr.mask = cpu_to_le32(mask); 346 347 req->r_num_caps = 1; 348 err = ceph_mdsc_do_request(mdsc, NULL, req); 349 if (err) { 350 ceph_mdsc_put_request(req); 351 return ERR_PTR(err); 352 } 353 354 inode = req->r_target_inode; 355 if (inode) 356 ihold(inode); 357 ceph_mdsc_put_request(req); 358 if (!inode) 359 return ERR_PTR(-ENOENT); 360 361 return d_obtain_alias(inode); 362 } 363 364 static struct dentry *ceph_get_parent(struct dentry *child) 365 { 366 struct inode *inode = d_inode(child); 367 struct ceph_client *cl = ceph_inode_to_client(inode); 368 struct dentry *dn; 369 370 if (ceph_snap(inode) != CEPH_NOSNAP) { 371 struct inode* dir; 372 bool unlinked = false; 373 /* do not support non-directory */ 374 if (!d_is_dir(child)) { 375 dn = ERR_PTR(-EINVAL); 376 goto out; 377 } 378 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 379 if (IS_ERR(dir)) { 380 dn = ERR_CAST(dir); 381 goto out; 382 } 383 /* There can be multiple paths to access snapped inode. 384 * For simplicity, treat snapdir of head inode as parent */ 385 if (ceph_snap(inode) != CEPH_SNAPDIR) { 386 struct inode *snapdir = ceph_get_snapdir(dir); 387 if (dir->i_nlink == 0) 388 unlinked = true; 389 iput(dir); 390 if (IS_ERR(snapdir)) { 391 dn = ERR_CAST(snapdir); 392 goto out; 393 } 394 dir = snapdir; 395 } 396 /* If directory has already been deleted, futher get_parent 397 * will fail. Do not mark snapdir dentry as disconnected, 398 * this prevent exportfs from doing futher get_parent. */ 399 if (unlinked) 400 dn = d_obtain_root(dir); 401 else 402 dn = d_obtain_alias(dir); 403 } else { 404 dn = __get_parent(child->d_sb, child, 0); 405 } 406 out: 407 doutc(cl, "child %p %p %llx.%llx err=%ld\n", child, inode, 408 ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn)); 409 return dn; 410 } 411 412 /* 413 * convert regular fh to parent 414 */ 415 static struct dentry *ceph_fh_to_parent(struct super_block *sb, 416 struct fid *fid, 417 int fh_len, int fh_type) 418 { 419 struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb); 420 struct ceph_nfs_confh *cfh = (void *)fid->raw; 421 struct dentry *dentry; 422 423 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 424 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 425 return __snapfh_to_dentry(sb, sfh, true); 426 } 427 428 if (fh_type != FILEID_INO32_GEN_PARENT) 429 return NULL; 430 if (fh_len < sizeof(*cfh) / 4) 431 return NULL; 432 433 doutc(fsc->client, "%llx\n", cfh->parent_ino); 434 dentry = __get_parent(sb, NULL, cfh->ino); 435 if (unlikely(dentry == ERR_PTR(-ENOENT))) 436 dentry = __fh_to_dentry(sb, cfh->parent_ino); 437 return dentry; 438 } 439 440 static int __get_snap_name(struct dentry *parent, char *name, 441 struct dentry *child) 442 { 443 struct inode *inode = d_inode(child); 444 struct inode *dir = d_inode(parent); 445 struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode); 446 struct ceph_mds_request *req = NULL; 447 char *last_name = NULL; 448 unsigned next_offset = 2; 449 int err = -EINVAL; 450 451 if (ceph_ino(inode) != ceph_ino(dir)) 452 goto out; 453 if (ceph_snap(inode) == CEPH_SNAPDIR) { 454 if (ceph_snap(dir) == CEPH_NOSNAP) { 455 strcpy(name, fsc->mount_options->snapdir_name); 456 err = 0; 457 } 458 goto out; 459 } 460 if (ceph_snap(dir) != CEPH_SNAPDIR) 461 goto out; 462 463 while (1) { 464 struct ceph_mds_reply_info_parsed *rinfo; 465 struct ceph_mds_reply_dir_entry *rde; 466 int i; 467 468 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 469 USE_AUTH_MDS); 470 if (IS_ERR(req)) { 471 err = PTR_ERR(req); 472 req = NULL; 473 goto out; 474 } 475 err = ceph_alloc_readdir_reply_buffer(req, inode); 476 if (err) 477 goto out; 478 479 req->r_direct_mode = USE_AUTH_MDS; 480 req->r_readdir_offset = next_offset; 481 req->r_args.readdir.flags = 482 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 483 if (last_name) { 484 req->r_path2 = last_name; 485 last_name = NULL; 486 } 487 488 req->r_inode = dir; 489 ihold(dir); 490 req->r_dentry = dget(parent); 491 492 inode_lock(dir); 493 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 494 inode_unlock(dir); 495 496 if (err < 0) 497 goto out; 498 499 rinfo = &req->r_reply_info; 500 for (i = 0; i < rinfo->dir_nr; i++) { 501 rde = rinfo->dir_entries + i; 502 BUG_ON(!rde->inode.in); 503 if (ceph_snap(inode) == 504 le64_to_cpu(rde->inode.in->snapid)) { 505 memcpy(name, rde->name, rde->name_len); 506 name[rde->name_len] = '\0'; 507 err = 0; 508 goto out; 509 } 510 } 511 512 if (rinfo->dir_end) 513 break; 514 515 BUG_ON(rinfo->dir_nr <= 0); 516 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 517 next_offset += rinfo->dir_nr; 518 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 519 if (!last_name) { 520 err = -ENOMEM; 521 goto out; 522 } 523 524 ceph_mdsc_put_request(req); 525 req = NULL; 526 } 527 err = -ENOENT; 528 out: 529 if (req) 530 ceph_mdsc_put_request(req); 531 kfree(last_name); 532 doutc(fsc->client, "child dentry %p %p %llx.%llx err=%d\n", child, 533 inode, ceph_vinop(inode), err); 534 return err; 535 } 536 537 static int ceph_get_name(struct dentry *parent, char *name, 538 struct dentry *child) 539 { 540 struct ceph_mds_client *mdsc; 541 struct ceph_mds_request *req; 542 struct inode *dir = d_inode(parent); 543 struct inode *inode = d_inode(child); 544 struct ceph_mds_reply_info_parsed *rinfo; 545 int err; 546 547 if (ceph_snap(inode) != CEPH_NOSNAP) 548 return __get_snap_name(parent, name, child); 549 550 mdsc = ceph_inode_to_fs_client(inode)->mdsc; 551 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 552 USE_ANY_MDS); 553 if (IS_ERR(req)) 554 return PTR_ERR(req); 555 556 inode_lock(dir); 557 req->r_inode = inode; 558 ihold(inode); 559 req->r_ino2 = ceph_vino(d_inode(parent)); 560 req->r_parent = dir; 561 ihold(dir); 562 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 563 req->r_num_caps = 2; 564 err = ceph_mdsc_do_request(mdsc, NULL, req); 565 inode_unlock(dir); 566 567 if (err) 568 goto out; 569 570 rinfo = &req->r_reply_info; 571 if (!IS_ENCRYPTED(dir)) { 572 memcpy(name, rinfo->dname, rinfo->dname_len); 573 name[rinfo->dname_len] = 0; 574 } else { 575 struct fscrypt_str oname = FSTR_INIT(NULL, 0); 576 struct ceph_fname fname = { .dir = dir, 577 .name = rinfo->dname, 578 .ctext = rinfo->altname, 579 .name_len = rinfo->dname_len, 580 .ctext_len = rinfo->altname_len }; 581 582 err = ceph_fname_alloc_buffer(dir, &oname); 583 if (err < 0) 584 goto out; 585 586 err = ceph_fname_to_usr(&fname, NULL, &oname, NULL); 587 if (!err) { 588 memcpy(name, oname.name, oname.len); 589 name[oname.len] = 0; 590 } 591 ceph_fname_free_buffer(dir, &oname); 592 } 593 out: 594 doutc(mdsc->fsc->client, "child dentry %p %p %llx.%llx err %d %s%s\n", 595 child, inode, ceph_vinop(inode), err, err ? "" : "name ", 596 err ? "" : name); 597 ceph_mdsc_put_request(req); 598 return err; 599 } 600 601 const struct export_operations ceph_export_ops = { 602 .encode_fh = ceph_encode_fh, 603 .fh_to_dentry = ceph_fh_to_dentry, 604 .fh_to_parent = ceph_fh_to_parent, 605 .get_parent = ceph_get_parent, 606 .get_name = ceph_get_name, 607 }; 608