1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * CDDL HEADER START 4 * 5 * The contents of this file are subject to the terms of the 6 * Common Development and Distribution License (the "License"). 7 * You may not use this file except in compliance with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or https://opensource.org/licenses/CDDL-1.0. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (C) 2011 Lawrence Livermore National Security, LLC. 24 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). 25 * LLNL-CODE-403049. 26 * Rewritten for Linux by: 27 * Rohan Puri <rohan.puri15@gmail.com> 28 * Brian Behlendorf <behlendorf1@llnl.gov> 29 */ 30 31 #include <sys/zfs_znode.h> 32 #include <sys/zfs_vfsops.h> 33 #include <sys/zfs_vnops.h> 34 #include <sys/zfs_ctldir.h> 35 #include <sys/zpl.h> 36 #include <sys/dmu.h> 37 #include <sys/dsl_dataset.h> 38 #include <sys/zap.h> 39 40 /* 41 * Common open routine. Disallow any write access. 42 */ 43 static int 44 zpl_common_open(struct inode *ip, struct file *filp) 45 { 46 if (blk_mode_is_open_write(filp->f_mode)) 47 return (-EACCES); 48 49 return (generic_file_open(ip, filp)); 50 } 51 52 /* 53 * Get root directory contents. 54 */ 55 static int 56 zpl_root_iterate(struct file *filp, struct dir_context *ctx) 57 { 58 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 59 int error = 0; 60 61 if (zfsvfs->z_show_ctldir == ZFS_SNAPDIR_DISABLED) { 62 return (SET_ERROR(ENOENT)); 63 } 64 65 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 66 return (error); 67 68 if (!dir_emit_dots(filp, ctx)) 69 goto out; 70 71 if (ctx->pos == 2) { 72 if (!dir_emit(ctx, ZFS_SNAPDIR_NAME, 73 strlen(ZFS_SNAPDIR_NAME), ZFSCTL_INO_SNAPDIR, DT_DIR)) 74 goto out; 75 76 ctx->pos++; 77 } 78 79 if (ctx->pos == 3) { 80 if (!dir_emit(ctx, ZFS_SHAREDIR_NAME, 81 strlen(ZFS_SHAREDIR_NAME), ZFSCTL_INO_SHARES, DT_DIR)) 82 goto out; 83 84 ctx->pos++; 85 } 86 out: 87 zpl_exit(zfsvfs, FTAG); 88 89 return (error); 90 } 91 92 /* 93 * Get root directory attributes. 94 */ 95 static int 96 #ifdef HAVE_IDMAP_IOPS_GETATTR 97 zpl_root_getattr_impl(struct mnt_idmap *user_ns, 98 const struct path *path, struct kstat *stat, u32 request_mask, 99 unsigned int query_flags) 100 #elif defined(HAVE_USERNS_IOPS_GETATTR) 101 zpl_root_getattr_impl(struct user_namespace *user_ns, 102 const struct path *path, struct kstat *stat, u32 request_mask, 103 unsigned int query_flags) 104 #else 105 zpl_root_getattr_impl(const struct path *path, struct kstat *stat, 106 u32 request_mask, unsigned int query_flags) 107 #endif 108 { 109 (void) request_mask, (void) query_flags; 110 struct inode *ip = path->dentry->d_inode; 111 112 #if (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR)) 113 #ifdef HAVE_GENERIC_FILLATTR_USERNS 114 generic_fillattr(user_ns, ip, stat); 115 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP) 116 generic_fillattr(user_ns, ip, stat); 117 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK) 118 generic_fillattr(user_ns, request_mask, ip, stat); 119 #else 120 (void) user_ns; 121 #endif 122 #else 123 generic_fillattr(ip, stat); 124 #endif 125 stat->atime = current_time(ip); 126 127 return (0); 128 } 129 ZPL_GETATTR_WRAPPER(zpl_root_getattr); 130 131 static struct dentry * 132 zpl_root_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) 133 { 134 cred_t *cr = CRED(); 135 struct inode *ip; 136 int error; 137 138 crhold(cr); 139 error = -zfsctl_root_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); 140 ASSERT3S(error, <=, 0); 141 crfree(cr); 142 143 if (error) { 144 if (error == -ENOENT) 145 return (d_splice_alias(NULL, dentry)); 146 else 147 return (ERR_PTR(error)); 148 } 149 150 return (d_splice_alias(ip, dentry)); 151 } 152 153 /* 154 * The '.zfs' control directory file and inode operations. 155 */ 156 const struct file_operations zpl_fops_root = { 157 .open = zpl_common_open, 158 .llseek = generic_file_llseek, 159 .read = generic_read_dir, 160 .iterate_shared = zpl_root_iterate, 161 }; 162 163 const struct inode_operations zpl_ops_root = { 164 .lookup = zpl_root_lookup, 165 .getattr = zpl_root_getattr, 166 }; 167 168 static struct vfsmount * 169 zpl_snapdir_automount(struct path *path) 170 { 171 int error; 172 173 error = -zfsctl_snapshot_mount(path, 0); 174 if (error) 175 return (ERR_PTR(error)); 176 177 /* 178 * Rather than returning the new vfsmount for the snapshot we must 179 * return NULL to indicate a mount collision. This is done because 180 * the user space mount calls do_add_mount() which adds the vfsmount 181 * to the name space. If we returned the new mount here it would be 182 * added again to the vfsmount list resulting in list corruption. 183 */ 184 return (NULL); 185 } 186 187 /* 188 * Negative dentries must always be revalidated so newly created snapshots 189 * can be detected and automounted. Normal dentries should be kept because 190 * as of the 3.18 kernel revaliding the mountpoint dentry will result in 191 * the snapshot being immediately unmounted. 192 */ 193 #ifdef HAVE_D_REVALIDATE_4ARGS 194 static int 195 zpl_snapdir_revalidate(struct inode *dir, const struct qstr *name, 196 struct dentry *dentry, unsigned int flags) 197 #else 198 static int 199 zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags) 200 #endif 201 { 202 return (!!dentry->d_inode); 203 } 204 205 static dentry_operations_t zpl_dops_snapdirs = { 206 /* 207 * Auto mounting of snapshots is only supported for 2.6.37 and 208 * newer kernels. Prior to this kernel the ops->follow_link() 209 * callback was used as a hack to trigger the mount. The 210 * resulting vfsmount was then explicitly grafted in to the 211 * name space. While it might be possible to add compatibility 212 * code to accomplish this it would require considerable care. 213 */ 214 .d_automount = zpl_snapdir_automount, 215 .d_revalidate = zpl_snapdir_revalidate, 216 }; 217 218 static struct dentry * 219 zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, 220 unsigned int flags) 221 { 222 fstrans_cookie_t cookie; 223 cred_t *cr = CRED(); 224 struct inode *ip = NULL; 225 int error; 226 227 crhold(cr); 228 cookie = spl_fstrans_mark(); 229 error = -zfsctl_snapdir_lookup(dip, dname(dentry), &ip, 230 0, cr, NULL, NULL); 231 ASSERT3S(error, <=, 0); 232 spl_fstrans_unmark(cookie); 233 crfree(cr); 234 235 if (error && error != -ENOENT) 236 return (ERR_PTR(error)); 237 238 ASSERT(error == 0 || ip == NULL); 239 d_clear_d_op(dentry); 240 d_set_d_op(dentry, &zpl_dops_snapdirs); 241 dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; 242 243 return (d_splice_alias(ip, dentry)); 244 } 245 246 static int 247 zpl_snapdir_iterate(struct file *filp, struct dir_context *ctx) 248 { 249 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 250 fstrans_cookie_t cookie; 251 char snapname[MAXNAMELEN]; 252 boolean_t case_conflict; 253 uint64_t id, pos; 254 int error = 0; 255 256 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 257 return (error); 258 cookie = spl_fstrans_mark(); 259 260 if (!dir_emit_dots(filp, ctx)) 261 goto out; 262 263 /* Start the position at 0 if it already emitted . and .. */ 264 pos = (ctx->pos == 2 ? 0 : ctx->pos); 265 while (error == 0) { 266 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); 267 error = -dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, 268 snapname, &id, &pos, &case_conflict); 269 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); 270 if (error) 271 goto out; 272 273 if (!dir_emit(ctx, snapname, strlen(snapname), 274 ZFSCTL_INO_SHARES - id, DT_DIR)) 275 goto out; 276 277 ctx->pos = pos; 278 } 279 out: 280 spl_fstrans_unmark(cookie); 281 zpl_exit(zfsvfs, FTAG); 282 283 if (error == -ENOENT) 284 return (0); 285 286 return (error); 287 } 288 289 static int 290 #ifdef HAVE_IOPS_RENAME_USERNS 291 zpl_snapdir_rename2(struct user_namespace *user_ns, struct inode *sdip, 292 struct dentry *sdentry, struct inode *tdip, struct dentry *tdentry, 293 unsigned int flags) 294 #elif defined(HAVE_IOPS_RENAME_IDMAP) 295 zpl_snapdir_rename2(struct mnt_idmap *user_ns, struct inode *sdip, 296 struct dentry *sdentry, struct inode *tdip, struct dentry *tdentry, 297 unsigned int flags) 298 #else 299 zpl_snapdir_rename2(struct inode *sdip, struct dentry *sdentry, 300 struct inode *tdip, struct dentry *tdentry, unsigned int flags) 301 #endif 302 { 303 cred_t *cr = CRED(); 304 int error; 305 306 /* We probably don't want to support renameat2(2) in ctldir */ 307 if (flags) 308 return (-EINVAL); 309 310 crhold(cr); 311 error = -zfsctl_snapdir_rename(sdip, dname(sdentry), 312 tdip, dname(tdentry), cr, 0); 313 ASSERT3S(error, <=, 0); 314 crfree(cr); 315 316 return (error); 317 } 318 319 #if (!defined(HAVE_RENAME_WANTS_FLAGS) && \ 320 !defined(HAVE_IOPS_RENAME_USERNS) && \ 321 !defined(HAVE_IOPS_RENAME_IDMAP)) 322 static int 323 zpl_snapdir_rename(struct inode *sdip, struct dentry *sdentry, 324 struct inode *tdip, struct dentry *tdentry) 325 { 326 return (zpl_snapdir_rename2(sdip, sdentry, tdip, tdentry, 0)); 327 } 328 #endif 329 330 static int 331 zpl_snapdir_rmdir(struct inode *dip, struct dentry *dentry) 332 { 333 cred_t *cr = CRED(); 334 int error; 335 336 crhold(cr); 337 error = -zfsctl_snapdir_remove(dip, dname(dentry), cr, 0); 338 ASSERT3S(error, <=, 0); 339 crfree(cr); 340 341 return (error); 342 } 343 344 static int 345 #ifdef HAVE_IOPS_MKDIR_USERNS 346 zpl_snapdir_mkdir(struct user_namespace *user_ns, struct inode *dip, 347 struct dentry *dentry, umode_t mode) 348 #elif defined(HAVE_IOPS_MKDIR_IDMAP) 349 zpl_snapdir_mkdir(struct mnt_idmap *user_ns, struct inode *dip, 350 struct dentry *dentry, umode_t mode) 351 #else 352 zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode) 353 #endif 354 { 355 cred_t *cr = CRED(); 356 vattr_t *vap; 357 struct inode *ip; 358 int error; 359 360 crhold(cr); 361 vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP); 362 #if (defined(HAVE_IOPS_MKDIR_USERNS) || defined(HAVE_IOPS_MKDIR_IDMAP)) 363 zpl_vap_init(vap, dip, mode | S_IFDIR, cr, user_ns); 364 #else 365 zpl_vap_init(vap, dip, mode | S_IFDIR, cr, zfs_init_idmap); 366 #endif 367 368 error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0); 369 if (error == 0) { 370 d_clear_d_op(dentry); 371 d_set_d_op(dentry, &zpl_dops_snapdirs); 372 d_instantiate(dentry, ip); 373 } 374 375 kmem_free(vap, sizeof (vattr_t)); 376 ASSERT3S(error, <=, 0); 377 crfree(cr); 378 379 return (error); 380 } 381 382 /* 383 * Get snapshot directory attributes. 384 */ 385 static int 386 #ifdef HAVE_IDMAP_IOPS_GETATTR 387 zpl_snapdir_getattr_impl(struct mnt_idmap *user_ns, 388 const struct path *path, struct kstat *stat, u32 request_mask, 389 unsigned int query_flags) 390 #elif defined(HAVE_USERNS_IOPS_GETATTR) 391 zpl_snapdir_getattr_impl(struct user_namespace *user_ns, 392 const struct path *path, struct kstat *stat, u32 request_mask, 393 unsigned int query_flags) 394 #else 395 zpl_snapdir_getattr_impl(const struct path *path, struct kstat *stat, 396 u32 request_mask, unsigned int query_flags) 397 #endif 398 { 399 (void) request_mask, (void) query_flags; 400 struct inode *ip = path->dentry->d_inode; 401 zfsvfs_t *zfsvfs = ITOZSB(ip); 402 int error; 403 404 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 405 return (error); 406 #if (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR)) 407 #ifdef HAVE_GENERIC_FILLATTR_USERNS 408 generic_fillattr(user_ns, ip, stat); 409 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP) 410 generic_fillattr(user_ns, ip, stat); 411 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK) 412 generic_fillattr(user_ns, request_mask, ip, stat); 413 #else 414 (void) user_ns; 415 #endif 416 #else 417 generic_fillattr(ip, stat); 418 #endif 419 420 stat->nlink = stat->size = 2; 421 422 dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os); 423 if (dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0) { 424 uint64_t snap_count; 425 int err = zap_count( 426 dmu_objset_pool(ds->ds_objset)->dp_meta_objset, 427 dsl_dataset_phys(ds)->ds_snapnames_zapobj, &snap_count); 428 if (err != 0) { 429 zpl_exit(zfsvfs, FTAG); 430 return (-err); 431 } 432 stat->nlink += snap_count; 433 } 434 435 stat->ctime = stat->mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); 436 stat->atime = current_time(ip); 437 zpl_exit(zfsvfs, FTAG); 438 439 return (0); 440 } 441 ZPL_GETATTR_WRAPPER(zpl_snapdir_getattr); 442 443 /* 444 * The '.zfs/snapshot' directory file operations. These mainly control 445 * generating the list of available snapshots when doing an 'ls' in the 446 * directory. See zpl_snapdir_readdir(). 447 */ 448 const struct file_operations zpl_fops_snapdir = { 449 .open = zpl_common_open, 450 .llseek = generic_file_llseek, 451 .read = generic_read_dir, 452 .iterate_shared = zpl_snapdir_iterate, 453 454 }; 455 456 /* 457 * The '.zfs/snapshot' directory inode operations. These mainly control 458 * creating an inode for a snapshot directory and initializing the needed 459 * infrastructure to automount the snapshot. See zpl_snapdir_lookup(). 460 */ 461 const struct inode_operations zpl_ops_snapdir = { 462 .lookup = zpl_snapdir_lookup, 463 .getattr = zpl_snapdir_getattr, 464 #if (defined(HAVE_RENAME_WANTS_FLAGS) || \ 465 defined(HAVE_IOPS_RENAME_USERNS) || \ 466 defined(HAVE_IOPS_RENAME_IDMAP)) 467 .rename = zpl_snapdir_rename2, 468 #else 469 .rename = zpl_snapdir_rename, 470 #endif 471 .rmdir = zpl_snapdir_rmdir, 472 .mkdir = zpl_snapdir_mkdir, 473 }; 474 475 static struct dentry * 476 zpl_shares_lookup(struct inode *dip, struct dentry *dentry, 477 unsigned int flags) 478 { 479 fstrans_cookie_t cookie; 480 cred_t *cr = CRED(); 481 struct inode *ip = NULL; 482 int error; 483 484 crhold(cr); 485 cookie = spl_fstrans_mark(); 486 error = -zfsctl_shares_lookup(dip, dname(dentry), &ip, 487 0, cr, NULL, NULL); 488 ASSERT3S(error, <=, 0); 489 spl_fstrans_unmark(cookie); 490 crfree(cr); 491 492 if (error) { 493 if (error == -ENOENT) 494 return (d_splice_alias(NULL, dentry)); 495 else 496 return (ERR_PTR(error)); 497 } 498 499 return (d_splice_alias(ip, dentry)); 500 } 501 502 static int 503 zpl_shares_iterate(struct file *filp, struct dir_context *ctx) 504 { 505 fstrans_cookie_t cookie; 506 cred_t *cr = CRED(); 507 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 508 znode_t *dzp; 509 int error = 0; 510 511 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 512 return (error); 513 cookie = spl_fstrans_mark(); 514 515 if (zfsvfs->z_shares_dir == 0) { 516 dir_emit_dots(filp, ctx); 517 goto out; 518 } 519 520 error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); 521 if (error) 522 goto out; 523 524 crhold(cr); 525 error = -zfs_readdir(ZTOI(dzp), ctx, cr); 526 crfree(cr); 527 528 iput(ZTOI(dzp)); 529 out: 530 spl_fstrans_unmark(cookie); 531 zpl_exit(zfsvfs, FTAG); 532 ASSERT3S(error, <=, 0); 533 534 return (error); 535 } 536 537 static int 538 #ifdef HAVE_USERNS_IOPS_GETATTR 539 zpl_shares_getattr_impl(struct user_namespace *user_ns, 540 const struct path *path, struct kstat *stat, u32 request_mask, 541 unsigned int query_flags) 542 #elif defined(HAVE_IDMAP_IOPS_GETATTR) 543 zpl_shares_getattr_impl(struct mnt_idmap *user_ns, 544 const struct path *path, struct kstat *stat, u32 request_mask, 545 unsigned int query_flags) 546 #else 547 zpl_shares_getattr_impl(const struct path *path, struct kstat *stat, 548 u32 request_mask, unsigned int query_flags) 549 #endif 550 { 551 (void) request_mask, (void) query_flags; 552 struct inode *ip = path->dentry->d_inode; 553 zfsvfs_t *zfsvfs = ITOZSB(ip); 554 znode_t *dzp; 555 int error; 556 557 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 558 return (error); 559 560 if (zfsvfs->z_shares_dir == 0) { 561 #if (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR)) 562 #ifdef HAVE_GENERIC_FILLATTR_USERNS 563 generic_fillattr(user_ns, path->dentry->d_inode, stat); 564 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP) 565 generic_fillattr(user_ns, path->dentry->d_inode, stat); 566 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK) 567 generic_fillattr(user_ns, request_mask, ip, stat); 568 #else 569 (void) user_ns; 570 #endif 571 #else 572 generic_fillattr(path->dentry->d_inode, stat); 573 #endif 574 stat->nlink = stat->size = 2; 575 stat->atime = current_time(ip); 576 zpl_exit(zfsvfs, FTAG); 577 return (0); 578 } 579 580 error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); 581 if (error == 0) { 582 #ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK 583 error = -zfs_getattr_fast(user_ns, request_mask, ZTOI(dzp), 584 stat); 585 #elif (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR)) 586 error = -zfs_getattr_fast(user_ns, ZTOI(dzp), stat); 587 #else 588 error = -zfs_getattr_fast(kcred->user_ns, ZTOI(dzp), stat); 589 #endif 590 iput(ZTOI(dzp)); 591 } 592 593 zpl_exit(zfsvfs, FTAG); 594 ASSERT3S(error, <=, 0); 595 596 return (error); 597 } 598 ZPL_GETATTR_WRAPPER(zpl_shares_getattr); 599 600 /* 601 * The '.zfs/shares' directory file operations. 602 */ 603 const struct file_operations zpl_fops_shares = { 604 .open = zpl_common_open, 605 .llseek = generic_file_llseek, 606 .read = generic_read_dir, 607 .iterate_shared = zpl_shares_iterate, 608 }; 609 610 /* 611 * The '.zfs/shares' directory inode operations. 612 */ 613 const struct inode_operations zpl_ops_shares = { 614 .lookup = zpl_shares_lookup, 615 .getattr = zpl_shares_getattr, 616 }; 617