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