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 int err; 185 186 if (IS_ERR(inode)) 187 return ERR_CAST(inode); 188 /* We need LINK caps to reliably check i_nlink */ 189 err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); 190 if (err) { 191 iput(inode); 192 return ERR_PTR(err); 193 } 194 /* -ESTALE if inode as been unlinked and no file is open */ 195 if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { 196 iput(inode); 197 return ERR_PTR(-ESTALE); 198 } 199 return d_obtain_alias(inode); 200 } 201 202 static struct dentry *__snapfh_to_dentry(struct super_block *sb, 203 struct ceph_nfs_snapfh *sfh, 204 bool want_parent) 205 { 206 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 207 struct ceph_mds_request *req; 208 struct inode *inode; 209 struct ceph_vino vino; 210 int mask; 211 int err; 212 bool unlinked = false; 213 214 if (want_parent) { 215 vino.ino = sfh->parent_ino; 216 if (sfh->snapid == CEPH_SNAPDIR) 217 vino.snap = CEPH_NOSNAP; 218 else if (sfh->ino == sfh->parent_ino) 219 vino.snap = CEPH_SNAPDIR; 220 else 221 vino.snap = sfh->snapid; 222 } else { 223 vino.ino = sfh->ino; 224 vino.snap = sfh->snapid; 225 } 226 227 if (ceph_vino_is_reserved(vino)) 228 return ERR_PTR(-ESTALE); 229 230 inode = ceph_find_inode(sb, vino); 231 if (inode) { 232 if (ceph_inode_is_shutdown(inode)) { 233 iput(inode); 234 return ERR_PTR(-ESTALE); 235 } 236 return d_obtain_alias(inode); 237 } 238 239 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 240 USE_ANY_MDS); 241 if (IS_ERR(req)) 242 return ERR_CAST(req); 243 244 mask = CEPH_STAT_CAP_INODE; 245 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 246 mask |= CEPH_CAP_XATTR_SHARED; 247 req->r_args.lookupino.mask = cpu_to_le32(mask); 248 if (vino.snap < CEPH_NOSNAP) { 249 req->r_args.lookupino.snapid = cpu_to_le64(vino.snap); 250 if (!want_parent && sfh->ino != sfh->parent_ino) { 251 req->r_args.lookupino.parent = 252 cpu_to_le64(sfh->parent_ino); 253 req->r_args.lookupino.hash = 254 cpu_to_le32(sfh->hash); 255 } 256 } 257 258 req->r_ino1 = vino; 259 req->r_num_caps = 1; 260 err = ceph_mdsc_do_request(mdsc, NULL, req); 261 inode = req->r_target_inode; 262 if (inode) { 263 if (vino.snap == CEPH_SNAPDIR) { 264 if (inode->i_nlink == 0) 265 unlinked = true; 266 inode = ceph_get_snapdir(inode); 267 } else if (ceph_snap(inode) == vino.snap) { 268 ihold(inode); 269 } else { 270 /* mds does not support lookup snapped inode */ 271 inode = ERR_PTR(-EOPNOTSUPP); 272 } 273 } else { 274 inode = ERR_PTR(-ESTALE); 275 } 276 ceph_mdsc_put_request(req); 277 278 if (want_parent) { 279 dout("snapfh_to_parent %llx.%llx\n err=%d\n", 280 vino.ino, vino.snap, err); 281 } else { 282 dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d", 283 vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err); 284 } 285 if (IS_ERR(inode)) 286 return ERR_CAST(inode); 287 /* see comments in ceph_get_parent() */ 288 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode); 289 } 290 291 /* 292 * convert regular fh to dentry 293 */ 294 static struct dentry *ceph_fh_to_dentry(struct super_block *sb, 295 struct fid *fid, 296 int fh_len, int fh_type) 297 { 298 struct ceph_nfs_fh *fh = (void *)fid->raw; 299 300 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 301 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 302 return __snapfh_to_dentry(sb, sfh, false); 303 } 304 305 if (fh_type != FILEID_INO32_GEN && 306 fh_type != FILEID_INO32_GEN_PARENT) 307 return NULL; 308 if (fh_len < sizeof(*fh) / 4) 309 return NULL; 310 311 dout("fh_to_dentry %llx\n", fh->ino); 312 return __fh_to_dentry(sb, fh->ino); 313 } 314 315 static struct dentry *__get_parent(struct super_block *sb, 316 struct dentry *child, u64 ino) 317 { 318 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 319 struct ceph_mds_request *req; 320 struct inode *inode; 321 int mask; 322 int err; 323 324 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, 325 USE_ANY_MDS); 326 if (IS_ERR(req)) 327 return ERR_CAST(req); 328 329 if (child) { 330 req->r_inode = d_inode(child); 331 ihold(d_inode(child)); 332 } else { 333 req->r_ino1 = (struct ceph_vino) { 334 .ino = ino, 335 .snap = CEPH_NOSNAP, 336 }; 337 } 338 339 mask = CEPH_STAT_CAP_INODE; 340 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 341 mask |= CEPH_CAP_XATTR_SHARED; 342 req->r_args.getattr.mask = cpu_to_le32(mask); 343 344 req->r_num_caps = 1; 345 err = ceph_mdsc_do_request(mdsc, NULL, req); 346 if (err) { 347 ceph_mdsc_put_request(req); 348 return ERR_PTR(err); 349 } 350 351 inode = req->r_target_inode; 352 if (inode) 353 ihold(inode); 354 ceph_mdsc_put_request(req); 355 if (!inode) 356 return ERR_PTR(-ENOENT); 357 358 return d_obtain_alias(inode); 359 } 360 361 static struct dentry *ceph_get_parent(struct dentry *child) 362 { 363 struct inode *inode = d_inode(child); 364 struct dentry *dn; 365 366 if (ceph_snap(inode) != CEPH_NOSNAP) { 367 struct inode* dir; 368 bool unlinked = false; 369 /* do not support non-directory */ 370 if (!d_is_dir(child)) { 371 dn = ERR_PTR(-EINVAL); 372 goto out; 373 } 374 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 375 if (IS_ERR(dir)) { 376 dn = ERR_CAST(dir); 377 goto out; 378 } 379 /* There can be multiple paths to access snapped inode. 380 * For simplicity, treat snapdir of head inode as parent */ 381 if (ceph_snap(inode) != CEPH_SNAPDIR) { 382 struct inode *snapdir = ceph_get_snapdir(dir); 383 if (dir->i_nlink == 0) 384 unlinked = true; 385 iput(dir); 386 if (IS_ERR(snapdir)) { 387 dn = ERR_CAST(snapdir); 388 goto out; 389 } 390 dir = snapdir; 391 } 392 /* If directory has already been deleted, futher get_parent 393 * will fail. Do not mark snapdir dentry as disconnected, 394 * this prevent exportfs from doing futher get_parent. */ 395 if (unlinked) 396 dn = d_obtain_root(dir); 397 else 398 dn = d_obtain_alias(dir); 399 } else { 400 dn = __get_parent(child->d_sb, child, 0); 401 } 402 out: 403 dout("get_parent %p ino %llx.%llx err=%ld\n", 404 child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn)); 405 return dn; 406 } 407 408 /* 409 * convert regular fh to parent 410 */ 411 static struct dentry *ceph_fh_to_parent(struct super_block *sb, 412 struct fid *fid, 413 int fh_len, int fh_type) 414 { 415 struct ceph_nfs_confh *cfh = (void *)fid->raw; 416 struct dentry *dentry; 417 418 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 419 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 420 return __snapfh_to_dentry(sb, sfh, true); 421 } 422 423 if (fh_type != FILEID_INO32_GEN_PARENT) 424 return NULL; 425 if (fh_len < sizeof(*cfh) / 4) 426 return NULL; 427 428 dout("fh_to_parent %llx\n", cfh->parent_ino); 429 dentry = __get_parent(sb, NULL, cfh->ino); 430 if (unlikely(dentry == ERR_PTR(-ENOENT))) 431 dentry = __fh_to_dentry(sb, cfh->parent_ino); 432 return dentry; 433 } 434 435 static int __get_snap_name(struct dentry *parent, char *name, 436 struct dentry *child) 437 { 438 struct inode *inode = d_inode(child); 439 struct inode *dir = d_inode(parent); 440 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 441 struct ceph_mds_request *req = NULL; 442 char *last_name = NULL; 443 unsigned next_offset = 2; 444 int err = -EINVAL; 445 446 if (ceph_ino(inode) != ceph_ino(dir)) 447 goto out; 448 if (ceph_snap(inode) == CEPH_SNAPDIR) { 449 if (ceph_snap(dir) == CEPH_NOSNAP) { 450 strcpy(name, fsc->mount_options->snapdir_name); 451 err = 0; 452 } 453 goto out; 454 } 455 if (ceph_snap(dir) != CEPH_SNAPDIR) 456 goto out; 457 458 while (1) { 459 struct ceph_mds_reply_info_parsed *rinfo; 460 struct ceph_mds_reply_dir_entry *rde; 461 int i; 462 463 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 464 USE_AUTH_MDS); 465 if (IS_ERR(req)) { 466 err = PTR_ERR(req); 467 req = NULL; 468 goto out; 469 } 470 err = ceph_alloc_readdir_reply_buffer(req, inode); 471 if (err) 472 goto out; 473 474 req->r_direct_mode = USE_AUTH_MDS; 475 req->r_readdir_offset = next_offset; 476 req->r_args.readdir.flags = 477 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 478 if (last_name) { 479 req->r_path2 = last_name; 480 last_name = NULL; 481 } 482 483 req->r_inode = dir; 484 ihold(dir); 485 req->r_dentry = dget(parent); 486 487 inode_lock(dir); 488 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 489 inode_unlock(dir); 490 491 if (err < 0) 492 goto out; 493 494 rinfo = &req->r_reply_info; 495 for (i = 0; i < rinfo->dir_nr; i++) { 496 rde = rinfo->dir_entries + i; 497 BUG_ON(!rde->inode.in); 498 if (ceph_snap(inode) == 499 le64_to_cpu(rde->inode.in->snapid)) { 500 memcpy(name, rde->name, rde->name_len); 501 name[rde->name_len] = '\0'; 502 err = 0; 503 goto out; 504 } 505 } 506 507 if (rinfo->dir_end) 508 break; 509 510 BUG_ON(rinfo->dir_nr <= 0); 511 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 512 next_offset += rinfo->dir_nr; 513 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 514 if (!last_name) { 515 err = -ENOMEM; 516 goto out; 517 } 518 519 ceph_mdsc_put_request(req); 520 req = NULL; 521 } 522 err = -ENOENT; 523 out: 524 if (req) 525 ceph_mdsc_put_request(req); 526 kfree(last_name); 527 dout("get_snap_name %p ino %llx.%llx err=%d\n", 528 child, ceph_vinop(inode), err); 529 return err; 530 } 531 532 static int ceph_get_name(struct dentry *parent, char *name, 533 struct dentry *child) 534 { 535 struct ceph_mds_client *mdsc; 536 struct ceph_mds_request *req; 537 struct inode *inode = d_inode(child); 538 int err; 539 540 if (ceph_snap(inode) != CEPH_NOSNAP) 541 return __get_snap_name(parent, name, child); 542 543 mdsc = ceph_inode_to_client(inode)->mdsc; 544 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 545 USE_ANY_MDS); 546 if (IS_ERR(req)) 547 return PTR_ERR(req); 548 549 inode_lock(d_inode(parent)); 550 551 req->r_inode = inode; 552 ihold(inode); 553 req->r_ino2 = ceph_vino(d_inode(parent)); 554 req->r_parent = d_inode(parent); 555 ihold(req->r_parent); 556 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 557 req->r_num_caps = 2; 558 err = ceph_mdsc_do_request(mdsc, NULL, req); 559 560 inode_unlock(d_inode(parent)); 561 562 if (!err) { 563 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 564 memcpy(name, rinfo->dname, rinfo->dname_len); 565 name[rinfo->dname_len] = 0; 566 dout("get_name %p ino %llx.%llx name %s\n", 567 child, ceph_vinop(inode), name); 568 } else { 569 dout("get_name %p ino %llx.%llx err %d\n", 570 child, ceph_vinop(inode), err); 571 } 572 573 ceph_mdsc_put_request(req); 574 return err; 575 } 576 577 const struct export_operations ceph_export_ops = { 578 .encode_fh = ceph_encode_fh, 579 .fh_to_dentry = ceph_fh_to_dentry, 580 .fh_to_parent = ceph_fh_to_parent, 581 .get_parent = ceph_get_parent, 582 .get_name = ceph_get_name, 583 }; 584