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 */ 14struct ceph_nfs_fh { 15 u64 ino; 16} __attribute__ ((packed)); 17 18/* 19 * Larger fh that includes parent ino. 20 */ 21struct ceph_nfs_confh { 22 u64 ino, parent_ino; 23} __attribute__ ((packed)); 24 25/* 26 * fh for snapped inode 27 */ 28struct ceph_nfs_snapfh { 29 u64 ino; 30 u64 snapid; 31 u64 parent_ino; 32 u32 hash; 33} __attribute__ ((packed)); 34 35static 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; 80out: 81 dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret); 82 return ret; 83} 84 85static 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 123static 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 164struct 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 176static 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 197static 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 err = -EOPNOTSUPP; 262 inode = NULL; 263 } 264 } 265 ceph_mdsc_put_request(req); 266 267 if (want_parent) { 268 dout("snapfh_to_parent %llx.%llx\n err=%d\n", 269 vino.ino, vino.snap, err); 270 } else { 271 dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d", 272 vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err); 273 } 274 if (!inode) 275 return ERR_PTR(-ESTALE); 276 /* see comments in ceph_get_parent() */ 277 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode); 278} 279 280/* 281 * convert regular fh to dentry 282 */ 283static struct dentry *ceph_fh_to_dentry(struct super_block *sb, 284 struct fid *fid, 285 int fh_len, int fh_type) 286{ 287 struct ceph_nfs_fh *fh = (void *)fid->raw; 288 289 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 290 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 291 return __snapfh_to_dentry(sb, sfh, false); 292 } 293 294 if (fh_type != FILEID_INO32_GEN && 295 fh_type != FILEID_INO32_GEN_PARENT) 296 return NULL; 297 if (fh_len < sizeof(*fh) / 4) 298 return NULL; 299 300 dout("fh_to_dentry %llx\n", fh->ino); 301 return __fh_to_dentry(sb, fh->ino); 302} 303 304static struct dentry *__get_parent(struct super_block *sb, 305 struct dentry *child, u64 ino) 306{ 307 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; 308 struct ceph_mds_request *req; 309 struct inode *inode; 310 int mask; 311 int err; 312 313 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, 314 USE_ANY_MDS); 315 if (IS_ERR(req)) 316 return ERR_CAST(req); 317 318 if (child) { 319 req->r_inode = d_inode(child); 320 ihold(d_inode(child)); 321 } else { 322 req->r_ino1 = (struct ceph_vino) { 323 .ino = ino, 324 .snap = CEPH_NOSNAP, 325 }; 326 } 327 328 mask = CEPH_STAT_CAP_INODE; 329 if (ceph_security_xattr_wanted(d_inode(sb->s_root))) 330 mask |= CEPH_CAP_XATTR_SHARED; 331 req->r_args.getattr.mask = cpu_to_le32(mask); 332 333 req->r_num_caps = 1; 334 err = ceph_mdsc_do_request(mdsc, NULL, req); 335 if (err) { 336 ceph_mdsc_put_request(req); 337 return ERR_PTR(err); 338 } 339 340 inode = req->r_target_inode; 341 if (inode) 342 ihold(inode); 343 ceph_mdsc_put_request(req); 344 if (!inode) 345 return ERR_PTR(-ENOENT); 346 347 return d_obtain_alias(inode); 348} 349 350static struct dentry *ceph_get_parent(struct dentry *child) 351{ 352 struct inode *inode = d_inode(child); 353 struct dentry *dn; 354 355 if (ceph_snap(inode) != CEPH_NOSNAP) { 356 struct inode* dir; 357 bool unlinked = false; 358 /* do not support non-directory */ 359 if (!d_is_dir(child)) { 360 dn = ERR_PTR(-EINVAL); 361 goto out; 362 } 363 dir = __lookup_inode(inode->i_sb, ceph_ino(inode)); 364 if (IS_ERR(dir)) { 365 dn = ERR_CAST(dir); 366 goto out; 367 } 368 /* There can be multiple paths to access snapped inode. 369 * For simplicity, treat snapdir of head inode as parent */ 370 if (ceph_snap(inode) != CEPH_SNAPDIR) { 371 struct inode *snapdir = ceph_get_snapdir(dir); 372 if (dir->i_nlink == 0) 373 unlinked = true; 374 iput(dir); 375 if (IS_ERR(snapdir)) { 376 dn = ERR_CAST(snapdir); 377 goto out; 378 } 379 dir = snapdir; 380 } 381 /* If directory has already been deleted, futher get_parent 382 * will fail. Do not mark snapdir dentry as disconnected, 383 * this prevent exportfs from doing futher get_parent. */ 384 if (unlinked) 385 dn = d_obtain_root(dir); 386 else 387 dn = d_obtain_alias(dir); 388 } else { 389 dn = __get_parent(child->d_sb, child, 0); 390 } 391out: 392 dout("get_parent %p ino %llx.%llx err=%ld\n", 393 child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn)); 394 return dn; 395} 396 397/* 398 * convert regular fh to parent 399 */ 400static struct dentry *ceph_fh_to_parent(struct super_block *sb, 401 struct fid *fid, 402 int fh_len, int fh_type) 403{ 404 struct ceph_nfs_confh *cfh = (void *)fid->raw; 405 struct dentry *dentry; 406 407 if (fh_type == FILEID_BTRFS_WITH_PARENT) { 408 struct ceph_nfs_snapfh *sfh = (void *)fid->raw; 409 return __snapfh_to_dentry(sb, sfh, true); 410 } 411 412 if (fh_type != FILEID_INO32_GEN_PARENT) 413 return NULL; 414 if (fh_len < sizeof(*cfh) / 4) 415 return NULL; 416 417 dout("fh_to_parent %llx\n", cfh->parent_ino); 418 dentry = __get_parent(sb, NULL, cfh->ino); 419 if (unlikely(dentry == ERR_PTR(-ENOENT))) 420 dentry = __fh_to_dentry(sb, cfh->parent_ino); 421 return dentry; 422} 423 424static int __get_snap_name(struct dentry *parent, char *name, 425 struct dentry *child) 426{ 427 struct inode *inode = d_inode(child); 428 struct inode *dir = d_inode(parent); 429 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 430 struct ceph_mds_request *req = NULL; 431 char *last_name = NULL; 432 unsigned next_offset = 2; 433 int err = -EINVAL; 434 435 if (ceph_ino(inode) != ceph_ino(dir)) 436 goto out; 437 if (ceph_snap(inode) == CEPH_SNAPDIR) { 438 if (ceph_snap(dir) == CEPH_NOSNAP) { 439 strcpy(name, fsc->mount_options->snapdir_name); 440 err = 0; 441 } 442 goto out; 443 } 444 if (ceph_snap(dir) != CEPH_SNAPDIR) 445 goto out; 446 447 while (1) { 448 struct ceph_mds_reply_info_parsed *rinfo; 449 struct ceph_mds_reply_dir_entry *rde; 450 int i; 451 452 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP, 453 USE_AUTH_MDS); 454 if (IS_ERR(req)) { 455 err = PTR_ERR(req); 456 req = NULL; 457 goto out; 458 } 459 err = ceph_alloc_readdir_reply_buffer(req, inode); 460 if (err) 461 goto out; 462 463 req->r_direct_mode = USE_AUTH_MDS; 464 req->r_readdir_offset = next_offset; 465 req->r_args.readdir.flags = 466 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS); 467 if (last_name) { 468 req->r_path2 = last_name; 469 last_name = NULL; 470 } 471 472 req->r_inode = dir; 473 ihold(dir); 474 req->r_dentry = dget(parent); 475 476 inode_lock(dir); 477 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req); 478 inode_unlock(dir); 479 480 if (err < 0) 481 goto out; 482 483 rinfo = &req->r_reply_info; 484 for (i = 0; i < rinfo->dir_nr; i++) { 485 rde = rinfo->dir_entries + i; 486 BUG_ON(!rde->inode.in); 487 if (ceph_snap(inode) == 488 le64_to_cpu(rde->inode.in->snapid)) { 489 memcpy(name, rde->name, rde->name_len); 490 name[rde->name_len] = '\0'; 491 err = 0; 492 goto out; 493 } 494 } 495 496 if (rinfo->dir_end) 497 break; 498 499 BUG_ON(rinfo->dir_nr <= 0); 500 rde = rinfo->dir_entries + (rinfo->dir_nr - 1); 501 next_offset += rinfo->dir_nr; 502 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL); 503 if (!last_name) { 504 err = -ENOMEM; 505 goto out; 506 } 507 508 ceph_mdsc_put_request(req); 509 req = NULL; 510 } 511 err = -ENOENT; 512out: 513 if (req) 514 ceph_mdsc_put_request(req); 515 kfree(last_name); 516 dout("get_snap_name %p ino %llx.%llx err=%d\n", 517 child, ceph_vinop(inode), err); 518 return err; 519} 520 521static int ceph_get_name(struct dentry *parent, char *name, 522 struct dentry *child) 523{ 524 struct ceph_mds_client *mdsc; 525 struct ceph_mds_request *req; 526 struct inode *inode = d_inode(child); 527 int err; 528 529 if (ceph_snap(inode) != CEPH_NOSNAP) 530 return __get_snap_name(parent, name, child); 531 532 mdsc = ceph_inode_to_client(inode)->mdsc; 533 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, 534 USE_ANY_MDS); 535 if (IS_ERR(req)) 536 return PTR_ERR(req); 537 538 inode_lock(d_inode(parent)); 539 540 req->r_inode = inode; 541 ihold(inode); 542 req->r_ino2 = ceph_vino(d_inode(parent)); 543 req->r_parent = d_inode(parent); 544 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); 545 req->r_num_caps = 2; 546 err = ceph_mdsc_do_request(mdsc, NULL, req); 547 548 inode_unlock(d_inode(parent)); 549 550 if (!err) { 551 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 552 memcpy(name, rinfo->dname, rinfo->dname_len); 553 name[rinfo->dname_len] = 0; 554 dout("get_name %p ino %llx.%llx name %s\n", 555 child, ceph_vinop(inode), name); 556 } else { 557 dout("get_name %p ino %llx.%llx err %d\n", 558 child, ceph_vinop(inode), err); 559 } 560 561 ceph_mdsc_put_request(req); 562 return err; 563} 564 565const struct export_operations ceph_export_ops = { 566 .encode_fh = ceph_encode_fh, 567 .fh_to_dentry = ceph_fh_to_dentry, 568 .fh_to_parent = ceph_fh_to_parent, 569 .get_parent = ceph_get_parent, 570 .get_name = ceph_get_name, 571}; 572