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