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 const static 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 const static int handle_length = 89 sizeof(struct ceph_nfs_fh) >> 2; 90 const static 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 inode = req->r_target_inode; 319 if (inode) 320 ihold(inode); 321 ceph_mdsc_put_request(req); 322 if (!inode) 323 return ERR_PTR(-ENOENT); 324 325 return d_obtain_alias(inode); 326 } 327 328 static struct dentry *ceph_get_parent(struct dentry *child) 329 { 330 struct inode *inode = d_inode(child); 331 struct dentry *dn; 332 333 if (ceph_snap(inode) != CEPH_NOSNAP) { 334 struct inode* dir; 335 bool unlinked = false; 336 /* do not support non-directory */ 337 if (!d_is_dir(child)) { 338 dn = ERR_PTR(-EINVAL); 339 goto out; 340 } 341 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 342 if (IS_ERR(dir)) { 343 dn = ERR_CAST(dir); 344 goto out; 345 } 346 /* There can be multiple paths to access snapped inode. 347 * For simplicity, treat snapdir of head inode as parent */ 348 if (ceph_snap(inode) != CEPH_SNAPDIR) { 349 struct inode *snapdir = ceph_get_snapdir(dir); 350 if (dir->i_nlink == 0) 351 unlinked = true; 352 iput(dir); 353 if (IS_ERR(snapdir)) { 354 dn = ERR_CAST(snapdir); 355 goto out; 356 } 357 dir = snapdir; 358 } 359 /* If directory has already been deleted, futher get_parent 360 * will fail. Do not mark snapdir dentry as disconnected, 361 * this prevent exportfs from doing futher get_parent. */ 362 if (unlinked) 363 dn = d_obtain_root(dir); 364 else 365 dn = d_obtain_alias(dir); 366 } else { 367 dn = __get_parent(child->d_sb, child, 0); 368 } 369 out: 370 dout("get_parent %p ino %llx.%llx err=%ld\n", 371 child, ceph_vinop(inode), (IS_ERR(dn) ? PTR_ERR(dn) : 0)); 372 return dn; 373 } 374 375 /* 376 * convert regular fh to parent 377 */ 378 static struct dentry *ceph_fh_to_parent(struct super_block *sb, 379 struct fid *fid, 380 int fh_len, int fh_type) 381 { 382 struct ceph_nfs_confh *cfh = (void *)fid->raw; 383 struct dentry *dentry; 384 385 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 386 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 387 return __snapfh_to_dentry(sb, sfh, true); 388 } 389 390 if (fh_type != FILEID_INO32_GEN_PARENT) 391 return NULL; 392 if (fh_len < sizeof(*cfh) / 4) 393 return NULL; 394 395 dout("fh_to_parent %llx\n", cfh->parent_ino); 396 dentry = __get_parent(sb, NULL, cfh->ino); 397 if (unlikely(dentry == ERR_PTR(-ENOENT))) 398 dentry = __fh_to_dentry(sb, cfh->parent_ino); 399 return dentry; 400 } 401 402 static int __get_snap_name(struct dentry *parent, char *name, 403 struct dentry *child) 404 { 405 struct inode *inode = d_inode(child); 406 struct inode *dir = d_inode(parent); 407 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 408 struct ceph_mds_request *req = NULL; 409 char *last_name = NULL; 410 unsigned next_offset = 2; 411 int err = -EINVAL; 412 413 if (ceph_ino(inode) != ceph_ino(dir)) 414 goto out; 415 if (ceph_snap(inode) == CEPH_SNAPDIR) { 416 if (ceph_snap(dir) == CEPH_NOSNAP) { 417 strcpy(name, fsc->mount_options->snapdir_name); 418 err = 0; 419 } 420 goto out; 421 } 422 if (ceph_snap(dir) != CEPH_SNAPDIR) 423 goto out; 424 425 while (1) { 426 struct ceph_mds_reply_info_parsed *rinfo; 427 struct ceph_mds_reply_dir_entry *rde; 428 int i; 429 430 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 431 USE_AUTH_MDS); 432 if (IS_ERR(req)) { 433 err = PTR_ERR(req); 434 req = NULL; 435 goto out; 436 } 437 err = ceph_alloc_readdir_reply_buffer(req, inode); 438 if (err) 439 goto out; 440 441 req->r_direct_mode = USE_AUTH_MDS; 442 req->r_readdir_offset = next_offset; 443 req->r_args.readdir.flags = 444 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 445 if (last_name) { 446 req->r_path2 = last_name; 447 last_name = NULL; 448 } 449 450 req->r_inode = dir; 451 ihold(dir); 452 req->r_dentry = dget(parent); 453 454 inode_lock(dir); 455 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 456 inode_unlock(dir); 457 458 if (err < 0) 459 goto out; 460 461 rinfo = &req->r_reply_info; 462 for (i = 0; i < rinfo->dir_nr; i++) { 463 rde = rinfo->dir_entries + i; 464 BUG_ON(!rde->inode.in); 465 if (ceph_snap(inode) == 466 le64_to_cpu(rde->inode.in->snapid)) { 467 memcpy(name, rde->name, rde->name_len); 468 name[rde->name_len] = '\0'; 469 err = 0; 470 goto out; 471 } 472 } 473 474 if (rinfo->dir_end) 475 break; 476 477 BUG_ON(rinfo->dir_nr <= 0); 478 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 479 next_offset += rinfo->dir_nr; 480 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 481 if (!last_name) { 482 err = -ENOMEM; 483 goto out; 484 } 485 486 ceph_mdsc_put_request(req); 487 req = NULL; 488 } 489 err = -ENOENT; 490 out: 491 if (req) 492 ceph_mdsc_put_request(req); 493 kfree(last_name); 494 dout("get_snap_name %p ino %llx.%llx err=%d\n", 495 child, ceph_vinop(inode), err); 496 return err; 497 } 498 499 static int ceph_get_name(struct dentry *parent, char *name, 500 struct dentry *child) 501 { 502 struct ceph_mds_client *mdsc; 503 struct ceph_mds_request *req; 504 struct inode *inode = d_inode(child); 505 int err; 506 507 if (ceph_snap(inode) != CEPH_NOSNAP) 508 return __get_snap_name(parent, name, child); 509 510 mdsc = ceph_inode_to_client(inode)->mdsc; 511 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 512 USE_ANY_MDS); 513 if (IS_ERR(req)) 514 return PTR_ERR(req); 515 516 inode_lock(d_inode(parent)); 517 518 req->r_inode = inode; 519 ihold(inode); 520 req->r_ino2 = ceph_vino(d_inode(parent)); 521 req->r_parent = d_inode(parent); 522 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 523 req->r_num_caps = 2; 524 err = ceph_mdsc_do_request(mdsc, NULL, req); 525 526 inode_unlock(d_inode(parent)); 527 528 if (!err) { 529 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 530 memcpy(name, rinfo->dname, rinfo->dname_len); 531 name[rinfo->dname_len] = 0; 532 dout("get_name %p ino %llx.%llx name %s\n", 533 child, ceph_vinop(inode), name); 534 } else { 535 dout("get_name %p ino %llx.%llx err %d\n", 536 child, ceph_vinop(inode), err); 537 } 538 539 ceph_mdsc_put_request(req); 540 return err; 541 } 542 543 const struct export_operations ceph_export_ops = { 544 .encode_fh = ceph_encode_fh, 545 .fh_to_dentry = ceph_fh_to_dentry, 546 .fh_to_parent = ceph_fh_to_parent, 547 .get_parent = ceph_get_parent, 548 .get_name = ceph_get_name, 549 }; 550