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 } 161 return inode; 162 } 163 164 struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino) 165 { 166 struct inode *inode = __lookup_inode(sb, ino); 167 if (IS_ERR(inode)) 168 return inode; 169 if (inode->i_nlink == 0) { 170 iput(inode); 171 return ERR_PTR(-ESTALE); 172 } 173 return inode; 174 } 175 176 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) 177 { 178 struct inode *inode = __lookup_inode(sb, ino); 179 int err; 180 181 if (IS_ERR(inode)) 182 return ERR_CAST(inode); 183 /* We need LINK caps to reliably check i_nlink */ 184 err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); 185 if (err) { 186 iput(inode); 187 return ERR_PTR(err); 188 } 189 /* -ESTALE if inode as been unlinked and no file is open */ 190 if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { 191 iput(inode); 192 return ERR_PTR(-ESTALE); 193 } 194 return d_obtain_alias(inode); 195 } 196 197 static struct dentry *__snapfh_to_dentry(struct super_block *sb, 198 struct ceph_nfs_snapfh *sfh, 199 bool want_parent) 200 { 201 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 202 struct ceph_mds_request *req; 203 struct inode *inode; 204 struct ceph_vino vino; 205 int mask; 206 int err; 207 bool unlinked = false; 208 209 if (want_parent) { 210 vino.ino = sfh->parent_ino; 211 if (sfh->snapid == CEPH_SNAPDIR) 212 vino.snap = CEPH_NOSNAP; 213 else if (sfh->ino == sfh->parent_ino) 214 vino.snap = CEPH_SNAPDIR; 215 else 216 vino.snap = sfh->snapid; 217 } else { 218 vino.ino = sfh->ino; 219 vino.snap = sfh->snapid; 220 } 221 222 if (ceph_vino_is_reserved(vino)) 223 return ERR_PTR(-ESTALE); 224 225 inode = ceph_find_inode(sb, vino); 226 if (inode) 227 return d_obtain_alias(inode); 228 229 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 230 USE_ANY_MDS); 231 if (IS_ERR(req)) 232 return ERR_CAST(req); 233 234 mask = CEPH_STAT_CAP_INODE; 235 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 236 mask |= CEPH_CAP_XATTR_SHARED; 237 req->r_args.lookupino.mask = cpu_to_le32(mask); 238 if (vino.snap < CEPH_NOSNAP) { 239 req->r_args.lookupino.snapid = cpu_to_le64(vino.snap); 240 if (!want_parent && sfh->ino != sfh->parent_ino) { 241 req->r_args.lookupino.parent = 242 cpu_to_le64(sfh->parent_ino); 243 req->r_args.lookupino.hash = 244 cpu_to_le32(sfh->hash); 245 } 246 } 247 248 req->r_ino1 = vino; 249 req->r_num_caps = 1; 250 err = ceph_mdsc_do_request(mdsc, NULL, req); 251 inode = req->r_target_inode; 252 if (inode) { 253 if (vino.snap == CEPH_SNAPDIR) { 254 if (inode->i_nlink == 0) 255 unlinked = true; 256 inode = ceph_get_snapdir(inode); 257 } else if (ceph_snap(inode) == vino.snap) { 258 ihold(inode); 259 } else { 260 /* mds does not support lookup snapped inode */ 261 inode = ERR_PTR(-EOPNOTSUPP); 262 } 263 } else { 264 inode = ERR_PTR(-ESTALE); 265 } 266 ceph_mdsc_put_request(req); 267 268 if (want_parent) { 269 dout("snapfh_to_parent %llx.%llx\n err=%d\n", 270 vino.ino, vino.snap, err); 271 } else { 272 dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d", 273 vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err); 274 } 275 if (IS_ERR(inode)) 276 return ERR_CAST(inode); 277 /* see comments in ceph_get_parent() */ 278 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode); 279 } 280 281 /* 282 * convert regular fh to dentry 283 */ 284 static struct dentry *ceph_fh_to_dentry(struct super_block *sb, 285 struct fid *fid, 286 int fh_len, int fh_type) 287 { 288 struct ceph_nfs_fh *fh = (void *)fid->raw; 289 290 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 291 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 292 return __snapfh_to_dentry(sb, sfh, false); 293 } 294 295 if (fh_type != FILEID_INO32_GEN && 296 fh_type != FILEID_INO32_GEN_PARENT) 297 return NULL; 298 if (fh_len < sizeof(*fh) / 4) 299 return NULL; 300 301 dout("fh_to_dentry %llx\n", fh->ino); 302 return __fh_to_dentry(sb, fh->ino); 303 } 304 305 static struct dentry *__get_parent(struct super_block *sb, 306 struct dentry *child, u64 ino) 307 { 308 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 309 struct ceph_mds_request *req; 310 struct inode *inode; 311 int mask; 312 int err; 313 314 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, 315 USE_ANY_MDS); 316 if (IS_ERR(req)) 317 return ERR_CAST(req); 318 319 if (child) { 320 req->r_inode = d_inode(child); 321 ihold(d_inode(child)); 322 } else { 323 req->r_ino1 = (struct ceph_vino) { 324 .ino = ino, 325 .snap = CEPH_NOSNAP, 326 }; 327 } 328 329 mask = CEPH_STAT_CAP_INODE; 330 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 331 mask |= CEPH_CAP_XATTR_SHARED; 332 req->r_args.getattr.mask = cpu_to_le32(mask); 333 334 req->r_num_caps = 1; 335 err = ceph_mdsc_do_request(mdsc, NULL, req); 336 if (err) { 337 ceph_mdsc_put_request(req); 338 return ERR_PTR(err); 339 } 340 341 inode = req->r_target_inode; 342 if (inode) 343 ihold(inode); 344 ceph_mdsc_put_request(req); 345 if (!inode) 346 return ERR_PTR(-ENOENT); 347 348 return d_obtain_alias(inode); 349 } 350 351 static struct dentry *ceph_get_parent(struct dentry *child) 352 { 353 struct inode *inode = d_inode(child); 354 struct dentry *dn; 355 356 if (ceph_snap(inode) != CEPH_NOSNAP) { 357 struct inode* dir; 358 bool unlinked = false; 359 /* do not support non-directory */ 360 if (!d_is_dir(child)) { 361 dn = ERR_PTR(-EINVAL); 362 goto out; 363 } 364 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 365 if (IS_ERR(dir)) { 366 dn = ERR_CAST(dir); 367 goto out; 368 } 369 /* There can be multiple paths to access snapped inode. 370 * For simplicity, treat snapdir of head inode as parent */ 371 if (ceph_snap(inode) != CEPH_SNAPDIR) { 372 struct inode *snapdir = ceph_get_snapdir(dir); 373 if (dir->i_nlink == 0) 374 unlinked = true; 375 iput(dir); 376 if (IS_ERR(snapdir)) { 377 dn = ERR_CAST(snapdir); 378 goto out; 379 } 380 dir = snapdir; 381 } 382 /* If directory has already been deleted, futher get_parent 383 * will fail. Do not mark snapdir dentry as disconnected, 384 * this prevent exportfs from doing futher get_parent. */ 385 if (unlinked) 386 dn = d_obtain_root(dir); 387 else 388 dn = d_obtain_alias(dir); 389 } else { 390 dn = __get_parent(child->d_sb, child, 0); 391 } 392 out: 393 dout("get_parent %p ino %llx.%llx err=%ld\n", 394 child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn)); 395 return dn; 396 } 397 398 /* 399 * convert regular fh to parent 400 */ 401 static struct dentry *ceph_fh_to_parent(struct super_block *sb, 402 struct fid *fid, 403 int fh_len, int fh_type) 404 { 405 struct ceph_nfs_confh *cfh = (void *)fid->raw; 406 struct dentry *dentry; 407 408 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 409 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 410 return __snapfh_to_dentry(sb, sfh, true); 411 } 412 413 if (fh_type != FILEID_INO32_GEN_PARENT) 414 return NULL; 415 if (fh_len < sizeof(*cfh) / 4) 416 return NULL; 417 418 dout("fh_to_parent %llx\n", cfh->parent_ino); 419 dentry = __get_parent(sb, NULL, cfh->ino); 420 if (unlikely(dentry == ERR_PTR(-ENOENT))) 421 dentry = __fh_to_dentry(sb, cfh->parent_ino); 422 return dentry; 423 } 424 425 static int __get_snap_name(struct dentry *parent, char *name, 426 struct dentry *child) 427 { 428 struct inode *inode = d_inode(child); 429 struct inode *dir = d_inode(parent); 430 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 431 struct ceph_mds_request *req = NULL; 432 char *last_name = NULL; 433 unsigned next_offset = 2; 434 int err = -EINVAL; 435 436 if (ceph_ino(inode) != ceph_ino(dir)) 437 goto out; 438 if (ceph_snap(inode) == CEPH_SNAPDIR) { 439 if (ceph_snap(dir) == CEPH_NOSNAP) { 440 strcpy(name, fsc->mount_options->snapdir_name); 441 err = 0; 442 } 443 goto out; 444 } 445 if (ceph_snap(dir) != CEPH_SNAPDIR) 446 goto out; 447 448 while (1) { 449 struct ceph_mds_reply_info_parsed *rinfo; 450 struct ceph_mds_reply_dir_entry *rde; 451 int i; 452 453 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 454 USE_AUTH_MDS); 455 if (IS_ERR(req)) { 456 err = PTR_ERR(req); 457 req = NULL; 458 goto out; 459 } 460 err = ceph_alloc_readdir_reply_buffer(req, inode); 461 if (err) 462 goto out; 463 464 req->r_direct_mode = USE_AUTH_MDS; 465 req->r_readdir_offset = next_offset; 466 req->r_args.readdir.flags = 467 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 468 if (last_name) { 469 req->r_path2 = last_name; 470 last_name = NULL; 471 } 472 473 req->r_inode = dir; 474 ihold(dir); 475 req->r_dentry = dget(parent); 476 477 inode_lock(dir); 478 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 479 inode_unlock(dir); 480 481 if (err < 0) 482 goto out; 483 484 rinfo = &req->r_reply_info; 485 for (i = 0; i < rinfo->dir_nr; i++) { 486 rde = rinfo->dir_entries + i; 487 BUG_ON(!rde->inode.in); 488 if (ceph_snap(inode) == 489 le64_to_cpu(rde->inode.in->snapid)) { 490 memcpy(name, rde->name, rde->name_len); 491 name[rde->name_len] = '\0'; 492 err = 0; 493 goto out; 494 } 495 } 496 497 if (rinfo->dir_end) 498 break; 499 500 BUG_ON(rinfo->dir_nr <= 0); 501 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 502 next_offset += rinfo->dir_nr; 503 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 504 if (!last_name) { 505 err = -ENOMEM; 506 goto out; 507 } 508 509 ceph_mdsc_put_request(req); 510 req = NULL; 511 } 512 err = -ENOENT; 513 out: 514 if (req) 515 ceph_mdsc_put_request(req); 516 kfree(last_name); 517 dout("get_snap_name %p ino %llx.%llx err=%d\n", 518 child, ceph_vinop(inode), err); 519 return err; 520 } 521 522 static int ceph_get_name(struct dentry *parent, char *name, 523 struct dentry *child) 524 { 525 struct ceph_mds_client *mdsc; 526 struct ceph_mds_request *req; 527 struct inode *inode = d_inode(child); 528 int err; 529 530 if (ceph_snap(inode) != CEPH_NOSNAP) 531 return __get_snap_name(parent, name, child); 532 533 mdsc = ceph_inode_to_client(inode)->mdsc; 534 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 535 USE_ANY_MDS); 536 if (IS_ERR(req)) 537 return PTR_ERR(req); 538 539 inode_lock(d_inode(parent)); 540 541 req->r_inode = inode; 542 ihold(inode); 543 req->r_ino2 = ceph_vino(d_inode(parent)); 544 req->r_parent = d_inode(parent); 545 ihold(req->r_parent); 546 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 547 req->r_num_caps = 2; 548 err = ceph_mdsc_do_request(mdsc, NULL, req); 549 550 inode_unlock(d_inode(parent)); 551 552 if (!err) { 553 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 554 memcpy(name, rinfo->dname, rinfo->dname_len); 555 name[rinfo->dname_len] = 0; 556 dout("get_name %p ino %llx.%llx name %s\n", 557 child, ceph_vinop(inode), name); 558 } else { 559 dout("get_name %p ino %llx.%llx err %d\n", 560 child, ceph_vinop(inode), err); 561 } 562 563 ceph_mdsc_put_request(req); 564 return err; 565 } 566 567 const struct export_operations ceph_export_ops = { 568 .encode_fh = ceph_encode_fh, 569 .fh_to_dentry = ceph_fh_to_dentry, 570 .fh_to_parent = ceph_fh_to_parent, 571 .get_parent = ceph_get_parent, 572 .get_name = ceph_get_name, 573 }; 574