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 inode = ceph_find_inode(sb, vino); 133 if (!inode) { 134 struct ceph_mds_request *req; 135 int mask; 136 137 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 138 USE_ANY_MDS); 139 if (IS_ERR(req)) 140 return ERR_CAST(req); 141 142 mask = CEPH_STAT_CAP_INODE; 143 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 144 mask |= CEPH_CAP_XATTR_SHARED; 145 req->r_args.lookupino.mask = cpu_to_le32(mask); 146 147 req->r_ino1 = vino; 148 req->r_num_caps = 1; 149 err = ceph_mdsc_do_request(mdsc, NULL, req); 150 inode = req->r_target_inode; 151 if (inode) 152 ihold(inode); 153 ceph_mdsc_put_request(req); 154 if (!inode) 155 return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE); 156 } 157 return inode; 158 } 159 160 struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino) 161 { 162 struct inode *inode = __lookup_inode(sb, ino); 163 if (IS_ERR(inode)) 164 return inode; 165 if (inode->i_nlink == 0) { 166 iput(inode); 167 return ERR_PTR(-ESTALE); 168 } 169 return inode; 170 } 171 172 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) 173 { 174 struct inode *inode = __lookup_inode(sb, ino); 175 int err; 176 177 if (IS_ERR(inode)) 178 return ERR_CAST(inode); 179 /* We need LINK caps to reliably check i_nlink */ 180 err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); 181 if (err) 182 return ERR_PTR(err); 183 /* -ESTALE if inode as been unlinked and no file is open */ 184 if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { 185 iput(inode); 186 return ERR_PTR(-ESTALE); 187 } 188 return d_obtain_alias(inode); 189 } 190 191 static struct dentry *__snapfh_to_dentry(struct super_block *sb, 192 struct ceph_nfs_snapfh *sfh, 193 bool want_parent) 194 { 195 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 196 struct ceph_mds_request *req; 197 struct inode *inode; 198 struct ceph_vino vino; 199 int mask; 200 int err; 201 bool unlinked = false; 202 203 if (want_parent) { 204 vino.ino = sfh->parent_ino; 205 if (sfh->snapid == CEPH_SNAPDIR) 206 vino.snap = CEPH_NOSNAP; 207 else if (sfh->ino == sfh->parent_ino) 208 vino.snap = CEPH_SNAPDIR; 209 else 210 vino.snap = sfh->snapid; 211 } else { 212 vino.ino = sfh->ino; 213 vino.snap = sfh->snapid; 214 } 215 inode = ceph_find_inode(sb, vino); 216 if (inode) 217 return d_obtain_alias(inode); 218 219 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, 220 USE_ANY_MDS); 221 if (IS_ERR(req)) 222 return ERR_CAST(req); 223 224 mask = CEPH_STAT_CAP_INODE; 225 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 226 mask |= CEPH_CAP_XATTR_SHARED; 227 req->r_args.lookupino.mask = cpu_to_le32(mask); 228 if (vino.snap < CEPH_NOSNAP) { 229 req->r_args.lookupino.snapid = cpu_to_le64(vino.snap); 230 if (!want_parent && sfh->ino != sfh->parent_ino) { 231 req->r_args.lookupino.parent = 232 cpu_to_le64(sfh->parent_ino); 233 req->r_args.lookupino.hash = 234 cpu_to_le32(sfh->hash); 235 } 236 } 237 238 req->r_ino1 = vino; 239 req->r_num_caps = 1; 240 err = ceph_mdsc_do_request(mdsc, NULL, req); 241 inode = req->r_target_inode; 242 if (inode) { 243 if (vino.snap == CEPH_SNAPDIR) { 244 if (inode->i_nlink == 0) 245 unlinked = true; 246 inode = ceph_get_snapdir(inode); 247 } else if (ceph_snap(inode) == vino.snap) { 248 ihold(inode); 249 } else { 250 /* mds does not support lookup snapped inode */ 251 inode = ERR_PTR(-EOPNOTSUPP); 252 } 253 } else { 254 inode = ERR_PTR(-ESTALE); 255 } 256 ceph_mdsc_put_request(req); 257 258 if (want_parent) { 259 dout("snapfh_to_parent %llx.%llx\n err=%d\n", 260 vino.ino, vino.snap, err); 261 } else { 262 dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d", 263 vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err); 264 } 265 if (IS_ERR(inode)) 266 return ERR_CAST(inode); 267 /* see comments in ceph_get_parent() */ 268 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode); 269 } 270 271 /* 272 * convert regular fh to dentry 273 */ 274 static struct dentry *ceph_fh_to_dentry(struct super_block *sb, 275 struct fid *fid, 276 int fh_len, int fh_type) 277 { 278 struct ceph_nfs_fh *fh = (void *)fid->raw; 279 280 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 281 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 282 return __snapfh_to_dentry(sb, sfh, false); 283 } 284 285 if (fh_type != FILEID_INO32_GEN && 286 fh_type != FILEID_INO32_GEN_PARENT) 287 return NULL; 288 if (fh_len < sizeof(*fh) / 4) 289 return NULL; 290 291 dout("fh_to_dentry %llx\n", fh->ino); 292 return __fh_to_dentry(sb, fh->ino); 293 } 294 295 static struct dentry *__get_parent(struct super_block *sb, 296 struct dentry *child, u64 ino) 297 { 298 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 299 struct ceph_mds_request *req; 300 struct inode *inode; 301 int mask; 302 int err; 303 304 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, 305 USE_ANY_MDS); 306 if (IS_ERR(req)) 307 return ERR_CAST(req); 308 309 if (child) { 310 req->r_inode = d_inode(child); 311 ihold(d_inode(child)); 312 } else { 313 req->r_ino1 = (struct ceph_vino) { 314 .ino = ino, 315 .snap = CEPH_NOSNAP, 316 }; 317 } 318 319 mask = CEPH_STAT_CAP_INODE; 320 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 321 mask |= CEPH_CAP_XATTR_SHARED; 322 req->r_args.getattr.mask = cpu_to_le32(mask); 323 324 req->r_num_caps = 1; 325 err = ceph_mdsc_do_request(mdsc, NULL, req); 326 if (err) { 327 ceph_mdsc_put_request(req); 328 return ERR_PTR(err); 329 } 330 331 inode = req->r_target_inode; 332 if (inode) 333 ihold(inode); 334 ceph_mdsc_put_request(req); 335 if (!inode) 336 return ERR_PTR(-ENOENT); 337 338 return d_obtain_alias(inode); 339 } 340 341 static struct dentry *ceph_get_parent(struct dentry *child) 342 { 343 struct inode *inode = d_inode(child); 344 struct dentry *dn; 345 346 if (ceph_snap(inode) != CEPH_NOSNAP) { 347 struct inode* dir; 348 bool unlinked = false; 349 /* do not support non-directory */ 350 if (!d_is_dir(child)) { 351 dn = ERR_PTR(-EINVAL); 352 goto out; 353 } 354 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 355 if (IS_ERR(dir)) { 356 dn = ERR_CAST(dir); 357 goto out; 358 } 359 /* There can be multiple paths to access snapped inode. 360 * For simplicity, treat snapdir of head inode as parent */ 361 if (ceph_snap(inode) != CEPH_SNAPDIR) { 362 struct inode *snapdir = ceph_get_snapdir(dir); 363 if (dir->i_nlink == 0) 364 unlinked = true; 365 iput(dir); 366 if (IS_ERR(snapdir)) { 367 dn = ERR_CAST(snapdir); 368 goto out; 369 } 370 dir = snapdir; 371 } 372 /* If directory has already been deleted, futher get_parent 373 * will fail. Do not mark snapdir dentry as disconnected, 374 * this prevent exportfs from doing futher get_parent. */ 375 if (unlinked) 376 dn = d_obtain_root(dir); 377 else 378 dn = d_obtain_alias(dir); 379 } else { 380 dn = __get_parent(child->d_sb, child, 0); 381 } 382 out: 383 dout("get_parent %p ino %llx.%llx err=%ld\n", 384 child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn)); 385 return dn; 386 } 387 388 /* 389 * convert regular fh to parent 390 */ 391 static struct dentry *ceph_fh_to_parent(struct super_block *sb, 392 struct fid *fid, 393 int fh_len, int fh_type) 394 { 395 struct ceph_nfs_confh *cfh = (void *)fid->raw; 396 struct dentry *dentry; 397 398 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 399 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 400 return __snapfh_to_dentry(sb, sfh, true); 401 } 402 403 if (fh_type != FILEID_INO32_GEN_PARENT) 404 return NULL; 405 if (fh_len < sizeof(*cfh) / 4) 406 return NULL; 407 408 dout("fh_to_parent %llx\n", cfh->parent_ino); 409 dentry = __get_parent(sb, NULL, cfh->ino); 410 if (unlikely(dentry == ERR_PTR(-ENOENT))) 411 dentry = __fh_to_dentry(sb, cfh->parent_ino); 412 return dentry; 413 } 414 415 static int __get_snap_name(struct dentry *parent, char *name, 416 struct dentry *child) 417 { 418 struct inode *inode = d_inode(child); 419 struct inode *dir = d_inode(parent); 420 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 421 struct ceph_mds_request *req = NULL; 422 char *last_name = NULL; 423 unsigned next_offset = 2; 424 int err = -EINVAL; 425 426 if (ceph_ino(inode) != ceph_ino(dir)) 427 goto out; 428 if (ceph_snap(inode) == CEPH_SNAPDIR) { 429 if (ceph_snap(dir) == CEPH_NOSNAP) { 430 strcpy(name, fsc->mount_options->snapdir_name); 431 err = 0; 432 } 433 goto out; 434 } 435 if (ceph_snap(dir) != CEPH_SNAPDIR) 436 goto out; 437 438 while (1) { 439 struct ceph_mds_reply_info_parsed *rinfo; 440 struct ceph_mds_reply_dir_entry *rde; 441 int i; 442 443 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 444 USE_AUTH_MDS); 445 if (IS_ERR(req)) { 446 err = PTR_ERR(req); 447 req = NULL; 448 goto out; 449 } 450 err = ceph_alloc_readdir_reply_buffer(req, inode); 451 if (err) 452 goto out; 453 454 req->r_direct_mode = USE_AUTH_MDS; 455 req->r_readdir_offset = next_offset; 456 req->r_args.readdir.flags = 457 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 458 if (last_name) { 459 req->r_path2 = last_name; 460 last_name = NULL; 461 } 462 463 req->r_inode = dir; 464 ihold(dir); 465 req->r_dentry = dget(parent); 466 467 inode_lock(dir); 468 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 469 inode_unlock(dir); 470 471 if (err < 0) 472 goto out; 473 474 rinfo = &req->r_reply_info; 475 for (i = 0; i < rinfo->dir_nr; i++) { 476 rde = rinfo->dir_entries + i; 477 BUG_ON(!rde->inode.in); 478 if (ceph_snap(inode) == 479 le64_to_cpu(rde->inode.in->snapid)) { 480 memcpy(name, rde->name, rde->name_len); 481 name[rde->name_len] = '\0'; 482 err = 0; 483 goto out; 484 } 485 } 486 487 if (rinfo->dir_end) 488 break; 489 490 BUG_ON(rinfo->dir_nr <= 0); 491 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 492 next_offset += rinfo->dir_nr; 493 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 494 if (!last_name) { 495 err = -ENOMEM; 496 goto out; 497 } 498 499 ceph_mdsc_put_request(req); 500 req = NULL; 501 } 502 err = -ENOENT; 503 out: 504 if (req) 505 ceph_mdsc_put_request(req); 506 kfree(last_name); 507 dout("get_snap_name %p ino %llx.%llx err=%d\n", 508 child, ceph_vinop(inode), err); 509 return err; 510 } 511 512 static int ceph_get_name(struct dentry *parent, char *name, 513 struct dentry *child) 514 { 515 struct ceph_mds_client *mdsc; 516 struct ceph_mds_request *req; 517 struct inode *inode = d_inode(child); 518 int err; 519 520 if (ceph_snap(inode) != CEPH_NOSNAP) 521 return __get_snap_name(parent, name, child); 522 523 mdsc = ceph_inode_to_client(inode)->mdsc; 524 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 525 USE_ANY_MDS); 526 if (IS_ERR(req)) 527 return PTR_ERR(req); 528 529 inode_lock(d_inode(parent)); 530 531 req->r_inode = inode; 532 ihold(inode); 533 req->r_ino2 = ceph_vino(d_inode(parent)); 534 req->r_parent = d_inode(parent); 535 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 536 req->r_num_caps = 2; 537 err = ceph_mdsc_do_request(mdsc, NULL, req); 538 539 inode_unlock(d_inode(parent)); 540 541 if (!err) { 542 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 543 memcpy(name, rinfo->dname, rinfo->dname_len); 544 name[rinfo->dname_len] = 0; 545 dout("get_name %p ino %llx.%llx name %s\n", 546 child, ceph_vinop(inode), name); 547 } else { 548 dout("get_name %p ino %llx.%llx err %d\n", 549 child, ceph_vinop(inode), err); 550 } 551 552 ceph_mdsc_put_request(req); 553 return err; 554 } 555 556 const struct export_operations ceph_export_ops = { 557 .encode_fh = ceph_encode_fh, 558 .fh_to_dentry = ceph_fh_to_dentry, 559 .fh_to_parent = ceph_fh_to_parent, 560 .get_parent = ceph_get_parent, 561 .get_name = ceph_get_name, 562 }; 563