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 (filp->f_mode & FMODE_WRITE) 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, zpl_dir_context_t *ctx) 56 { 57 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 58 int error = 0; 59 60 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 61 return (error); 62 63 if (!zpl_dir_emit_dots(filp, ctx)) 64 goto out; 65 66 if (ctx->pos == 2) { 67 if (!zpl_dir_emit(ctx, ZFS_SNAPDIR_NAME, 68 strlen(ZFS_SNAPDIR_NAME), ZFSCTL_INO_SNAPDIR, DT_DIR)) 69 goto out; 70 71 ctx->pos++; 72 } 73 74 if (ctx->pos == 3) { 75 if (!zpl_dir_emit(ctx, ZFS_SHAREDIR_NAME, 76 strlen(ZFS_SHAREDIR_NAME), ZFSCTL_INO_SHARES, DT_DIR)) 77 goto out; 78 79 ctx->pos++; 80 } 81 out: 82 zpl_exit(zfsvfs, FTAG); 83 84 return (error); 85 } 86 87 #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) 88 static int 89 zpl_root_readdir(struct file *filp, void *dirent, filldir_t filldir) 90 { 91 zpl_dir_context_t ctx = 92 ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); 93 int error; 94 95 error = zpl_root_iterate(filp, &ctx); 96 filp->f_pos = ctx.pos; 97 98 return (error); 99 } 100 #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ 101 102 /* 103 * Get root directory attributes. 104 */ 105 static int 106 #ifdef HAVE_USERNS_IOPS_GETATTR 107 zpl_root_getattr_impl(struct user_namespace *user_ns, 108 const struct path *path, struct kstat *stat, u32 request_mask, 109 unsigned int query_flags) 110 #else 111 zpl_root_getattr_impl(const struct path *path, struct kstat *stat, 112 u32 request_mask, unsigned int query_flags) 113 #endif 114 { 115 (void) request_mask, (void) query_flags; 116 struct inode *ip = path->dentry->d_inode; 117 118 #ifdef HAVE_USERNS_IOPS_GETATTR 119 #ifdef HAVE_GENERIC_FILLATTR_USERNS 120 generic_fillattr(user_ns, ip, stat); 121 #else 122 (void) user_ns; 123 #endif 124 #else 125 generic_fillattr(ip, stat); 126 #endif 127 stat->atime = current_time(ip); 128 129 return (0); 130 } 131 ZPL_GETATTR_WRAPPER(zpl_root_getattr); 132 133 static struct dentry * 134 zpl_root_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) 135 { 136 cred_t *cr = CRED(); 137 struct inode *ip; 138 int error; 139 140 crhold(cr); 141 error = -zfsctl_root_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); 142 ASSERT3S(error, <=, 0); 143 crfree(cr); 144 145 if (error) { 146 if (error == -ENOENT) 147 return (d_splice_alias(NULL, dentry)); 148 else 149 return (ERR_PTR(error)); 150 } 151 152 return (d_splice_alias(ip, dentry)); 153 } 154 155 /* 156 * The '.zfs' control directory file and inode operations. 157 */ 158 const struct file_operations zpl_fops_root = { 159 .open = zpl_common_open, 160 .llseek = generic_file_llseek, 161 .read = generic_read_dir, 162 #ifdef HAVE_VFS_ITERATE_SHARED 163 .iterate_shared = zpl_root_iterate, 164 #elif defined(HAVE_VFS_ITERATE) 165 .iterate = zpl_root_iterate, 166 #else 167 .readdir = zpl_root_readdir, 168 #endif 169 }; 170 171 const struct inode_operations zpl_ops_root = { 172 .lookup = zpl_root_lookup, 173 .getattr = zpl_root_getattr, 174 }; 175 176 static struct vfsmount * 177 zpl_snapdir_automount(struct path *path) 178 { 179 int error; 180 181 error = -zfsctl_snapshot_mount(path, 0); 182 if (error) 183 return (ERR_PTR(error)); 184 185 /* 186 * Rather than returning the new vfsmount for the snapshot we must 187 * return NULL to indicate a mount collision. This is done because 188 * the user space mount calls do_add_mount() which adds the vfsmount 189 * to the name space. If we returned the new mount here it would be 190 * added again to the vfsmount list resulting in list corruption. 191 */ 192 return (NULL); 193 } 194 195 /* 196 * Negative dentries must always be revalidated so newly created snapshots 197 * can be detected and automounted. Normal dentries should be kept because 198 * as of the 3.18 kernel revaliding the mountpoint dentry will result in 199 * the snapshot being immediately unmounted. 200 */ 201 static int 202 #ifdef HAVE_D_REVALIDATE_NAMEIDATA 203 zpl_snapdir_revalidate(struct dentry *dentry, struct nameidata *i) 204 #else 205 zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags) 206 #endif 207 { 208 return (!!dentry->d_inode); 209 } 210 211 static dentry_operations_t zpl_dops_snapdirs = { 212 /* 213 * Auto mounting of snapshots is only supported for 2.6.37 and 214 * newer kernels. Prior to this kernel the ops->follow_link() 215 * callback was used as a hack to trigger the mount. The 216 * resulting vfsmount was then explicitly grafted in to the 217 * name space. While it might be possible to add compatibility 218 * code to accomplish this it would require considerable care. 219 */ 220 .d_automount = zpl_snapdir_automount, 221 .d_revalidate = zpl_snapdir_revalidate, 222 }; 223 224 static struct dentry * 225 zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, 226 unsigned int flags) 227 { 228 fstrans_cookie_t cookie; 229 cred_t *cr = CRED(); 230 struct inode *ip = NULL; 231 int error; 232 233 crhold(cr); 234 cookie = spl_fstrans_mark(); 235 error = -zfsctl_snapdir_lookup(dip, dname(dentry), &ip, 236 0, cr, NULL, NULL); 237 ASSERT3S(error, <=, 0); 238 spl_fstrans_unmark(cookie); 239 crfree(cr); 240 241 if (error && error != -ENOENT) 242 return (ERR_PTR(error)); 243 244 ASSERT(error == 0 || ip == NULL); 245 d_clear_d_op(dentry); 246 d_set_d_op(dentry, &zpl_dops_snapdirs); 247 dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; 248 249 return (d_splice_alias(ip, dentry)); 250 } 251 252 static int 253 zpl_snapdir_iterate(struct file *filp, zpl_dir_context_t *ctx) 254 { 255 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 256 fstrans_cookie_t cookie; 257 char snapname[MAXNAMELEN]; 258 boolean_t case_conflict; 259 uint64_t id, pos; 260 int error = 0; 261 262 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 263 return (error); 264 cookie = spl_fstrans_mark(); 265 266 if (!zpl_dir_emit_dots(filp, ctx)) 267 goto out; 268 269 /* Start the position at 0 if it already emitted . and .. */ 270 pos = (ctx->pos == 2 ? 0 : ctx->pos); 271 while (error == 0) { 272 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); 273 error = -dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, 274 snapname, &id, &pos, &case_conflict); 275 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); 276 if (error) 277 goto out; 278 279 if (!zpl_dir_emit(ctx, snapname, strlen(snapname), 280 ZFSCTL_INO_SHARES - id, DT_DIR)) 281 goto out; 282 283 ctx->pos = pos; 284 } 285 out: 286 spl_fstrans_unmark(cookie); 287 zpl_exit(zfsvfs, FTAG); 288 289 if (error == -ENOENT) 290 return (0); 291 292 return (error); 293 } 294 295 #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) 296 static int 297 zpl_snapdir_readdir(struct file *filp, void *dirent, filldir_t filldir) 298 { 299 zpl_dir_context_t ctx = 300 ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); 301 int error; 302 303 error = zpl_snapdir_iterate(filp, &ctx); 304 filp->f_pos = ctx.pos; 305 306 return (error); 307 } 308 #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ 309 310 static int 311 #ifdef HAVE_IOPS_RENAME_USERNS 312 zpl_snapdir_rename2(struct user_namespace *user_ns, struct inode *sdip, 313 struct dentry *sdentry, struct inode *tdip, struct dentry *tdentry, 314 unsigned int flags) 315 #else 316 zpl_snapdir_rename2(struct inode *sdip, struct dentry *sdentry, 317 struct inode *tdip, struct dentry *tdentry, unsigned int flags) 318 #endif 319 { 320 cred_t *cr = CRED(); 321 int error; 322 323 /* We probably don't want to support renameat2(2) in ctldir */ 324 if (flags) 325 return (-EINVAL); 326 327 crhold(cr); 328 error = -zfsctl_snapdir_rename(sdip, dname(sdentry), 329 tdip, dname(tdentry), cr, 0); 330 ASSERT3S(error, <=, 0); 331 crfree(cr); 332 333 return (error); 334 } 335 336 #if !defined(HAVE_RENAME_WANTS_FLAGS) && !defined(HAVE_IOPS_RENAME_USERNS) 337 static int 338 zpl_snapdir_rename(struct inode *sdip, struct dentry *sdentry, 339 struct inode *tdip, struct dentry *tdentry) 340 { 341 return (zpl_snapdir_rename2(sdip, sdentry, tdip, tdentry, 0)); 342 } 343 #endif 344 345 static int 346 zpl_snapdir_rmdir(struct inode *dip, struct dentry *dentry) 347 { 348 cred_t *cr = CRED(); 349 int error; 350 351 crhold(cr); 352 error = -zfsctl_snapdir_remove(dip, dname(dentry), cr, 0); 353 ASSERT3S(error, <=, 0); 354 crfree(cr); 355 356 return (error); 357 } 358 359 static int 360 #ifdef HAVE_IOPS_MKDIR_USERNS 361 zpl_snapdir_mkdir(struct user_namespace *user_ns, struct inode *dip, 362 struct dentry *dentry, umode_t mode) 363 #else 364 zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode) 365 #endif 366 { 367 cred_t *cr = CRED(); 368 vattr_t *vap; 369 struct inode *ip; 370 int error; 371 372 crhold(cr); 373 vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP); 374 zpl_vap_init(vap, dip, mode | S_IFDIR, cr); 375 376 error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0); 377 if (error == 0) { 378 d_clear_d_op(dentry); 379 d_set_d_op(dentry, &zpl_dops_snapdirs); 380 d_instantiate(dentry, ip); 381 } 382 383 kmem_free(vap, sizeof (vattr_t)); 384 ASSERT3S(error, <=, 0); 385 crfree(cr); 386 387 return (error); 388 } 389 390 /* 391 * Get snapshot directory attributes. 392 */ 393 static int 394 #ifdef HAVE_USERNS_IOPS_GETATTR 395 zpl_snapdir_getattr_impl(struct user_namespace *user_ns, 396 const struct path *path, struct kstat *stat, u32 request_mask, 397 unsigned int query_flags) 398 #else 399 zpl_snapdir_getattr_impl(const struct path *path, struct kstat *stat, 400 u32 request_mask, unsigned int query_flags) 401 #endif 402 { 403 (void) request_mask, (void) query_flags; 404 struct inode *ip = path->dentry->d_inode; 405 zfsvfs_t *zfsvfs = ITOZSB(ip); 406 int error; 407 408 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 409 return (error); 410 #ifdef HAVE_USERNS_IOPS_GETATTR 411 #ifdef HAVE_GENERIC_FILLATTR_USERNS 412 generic_fillattr(user_ns, 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 #ifdef HAVE_VFS_ITERATE_SHARED 453 .iterate_shared = zpl_snapdir_iterate, 454 #elif defined(HAVE_VFS_ITERATE) 455 .iterate = zpl_snapdir_iterate, 456 #else 457 .readdir = zpl_snapdir_readdir, 458 #endif 459 460 }; 461 462 /* 463 * The '.zfs/snapshot' directory inode operations. These mainly control 464 * creating an inode for a snapshot directory and initializing the needed 465 * infrastructure to automount the snapshot. See zpl_snapdir_lookup(). 466 */ 467 const struct inode_operations zpl_ops_snapdir = { 468 .lookup = zpl_snapdir_lookup, 469 .getattr = zpl_snapdir_getattr, 470 #if defined(HAVE_RENAME_WANTS_FLAGS) || defined(HAVE_IOPS_RENAME_USERNS) 471 .rename = zpl_snapdir_rename2, 472 #else 473 .rename = zpl_snapdir_rename, 474 #endif 475 .rmdir = zpl_snapdir_rmdir, 476 .mkdir = zpl_snapdir_mkdir, 477 }; 478 479 static struct dentry * 480 zpl_shares_lookup(struct inode *dip, struct dentry *dentry, 481 unsigned int flags) 482 { 483 fstrans_cookie_t cookie; 484 cred_t *cr = CRED(); 485 struct inode *ip = NULL; 486 int error; 487 488 crhold(cr); 489 cookie = spl_fstrans_mark(); 490 error = -zfsctl_shares_lookup(dip, dname(dentry), &ip, 491 0, cr, NULL, NULL); 492 ASSERT3S(error, <=, 0); 493 spl_fstrans_unmark(cookie); 494 crfree(cr); 495 496 if (error) { 497 if (error == -ENOENT) 498 return (d_splice_alias(NULL, dentry)); 499 else 500 return (ERR_PTR(error)); 501 } 502 503 return (d_splice_alias(ip, dentry)); 504 } 505 506 static int 507 zpl_shares_iterate(struct file *filp, zpl_dir_context_t *ctx) 508 { 509 fstrans_cookie_t cookie; 510 cred_t *cr = CRED(); 511 zfsvfs_t *zfsvfs = ITOZSB(file_inode(filp)); 512 znode_t *dzp; 513 int error = 0; 514 515 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 516 return (error); 517 cookie = spl_fstrans_mark(); 518 519 if (zfsvfs->z_shares_dir == 0) { 520 zpl_dir_emit_dots(filp, ctx); 521 goto out; 522 } 523 524 error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); 525 if (error) 526 goto out; 527 528 crhold(cr); 529 error = -zfs_readdir(ZTOI(dzp), ctx, cr); 530 crfree(cr); 531 532 iput(ZTOI(dzp)); 533 out: 534 spl_fstrans_unmark(cookie); 535 zpl_exit(zfsvfs, FTAG); 536 ASSERT3S(error, <=, 0); 537 538 return (error); 539 } 540 541 #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) 542 static int 543 zpl_shares_readdir(struct file *filp, void *dirent, filldir_t filldir) 544 { 545 zpl_dir_context_t ctx = 546 ZPL_DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); 547 int error; 548 549 error = zpl_shares_iterate(filp, &ctx); 550 filp->f_pos = ctx.pos; 551 552 return (error); 553 } 554 #endif /* !HAVE_VFS_ITERATE && !HAVE_VFS_ITERATE_SHARED */ 555 556 static int 557 #ifdef HAVE_USERNS_IOPS_GETATTR 558 zpl_shares_getattr_impl(struct user_namespace *user_ns, 559 const struct path *path, struct kstat *stat, u32 request_mask, 560 unsigned int query_flags) 561 #else 562 zpl_shares_getattr_impl(const struct path *path, struct kstat *stat, 563 u32 request_mask, unsigned int query_flags) 564 #endif 565 { 566 (void) request_mask, (void) query_flags; 567 struct inode *ip = path->dentry->d_inode; 568 zfsvfs_t *zfsvfs = ITOZSB(ip); 569 znode_t *dzp; 570 int error; 571 572 if ((error = zpl_enter(zfsvfs, FTAG)) != 0) 573 return (error); 574 575 if (zfsvfs->z_shares_dir == 0) { 576 #ifdef HAVE_USERNS_IOPS_GETATTR 577 #ifdef HAVE_GENERIC_FILLATTR_USERNS 578 generic_fillattr(user_ns, path->dentry->d_inode, stat); 579 #else 580 (void) user_ns; 581 #endif 582 #else 583 generic_fillattr(path->dentry->d_inode, stat); 584 #endif 585 stat->nlink = stat->size = 2; 586 stat->atime = current_time(ip); 587 zpl_exit(zfsvfs, FTAG); 588 return (0); 589 } 590 591 error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp); 592 if (error == 0) { 593 #ifdef HAVE_USERNS_IOPS_GETATTR 594 #ifdef HAVE_GENERIC_FILLATTR_USERNS 595 error = -zfs_getattr_fast(user_ns, ZTOI(dzp), stat); 596 #else 597 (void) user_ns; 598 #endif 599 #else 600 error = -zfs_getattr_fast(kcred->user_ns, ZTOI(dzp), stat); 601 #endif 602 iput(ZTOI(dzp)); 603 } 604 605 zpl_exit(zfsvfs, FTAG); 606 ASSERT3S(error, <=, 0); 607 608 return (error); 609 } 610 ZPL_GETATTR_WRAPPER(zpl_shares_getattr); 611 612 /* 613 * The '.zfs/shares' directory file operations. 614 */ 615 const struct file_operations zpl_fops_shares = { 616 .open = zpl_common_open, 617 .llseek = generic_file_llseek, 618 .read = generic_read_dir, 619 #ifdef HAVE_VFS_ITERATE_SHARED 620 .iterate_shared = zpl_shares_iterate, 621 #elif defined(HAVE_VFS_ITERATE) 622 .iterate = zpl_shares_iterate, 623 #else 624 .readdir = zpl_shares_readdir, 625 #endif 626 627 }; 628 629 /* 630 * The '.zfs/shares' directory inode operations. 631 */ 632 const struct inode_operations zpl_ops_shares = { 633 .lookup = zpl_shares_lookup, 634 .getattr = zpl_shares_getattr, 635 }; 636