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