zfs_ctldir.c revision 302730
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 http://www.opensolaris.org/os/licensing. 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved. 25 */ 26 27/* 28 * ZFS control directory (a.k.a. ".zfs") 29 * 30 * This directory provides a common location for all ZFS meta-objects. 31 * Currently, this is only the 'snapshot' directory, but this may expand in the 32 * future. The elements are built using the GFS primitives, as the hierarchy 33 * does not actually exist on disk. 34 * 35 * For 'snapshot', we don't want to have all snapshots always mounted, because 36 * this would take up a huge amount of space in /etc/mnttab. We have three 37 * types of objects: 38 * 39 * ctldir ------> snapshotdir -------> snapshot 40 * | 41 * | 42 * V 43 * mounted fs 44 * 45 * The 'snapshot' node contains just enough information to lookup '..' and act 46 * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we 47 * perform an automount of the underlying filesystem and return the 48 * corresponding vnode. 49 * 50 * All mounts are handled automatically by the kernel, but unmounts are 51 * (currently) handled from user land. The main reason is that there is no 52 * reliable way to auto-unmount the filesystem when it's "no longer in use". 53 * When the user unmounts a filesystem, we call zfsctl_unmount(), which 54 * unmounts any snapshots within the snapshot directory. 55 * 56 * The '.zfs', '.zfs/snapshot', and all directories created under 57 * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and 58 * share the same vfs_t as the head filesystem (what '.zfs' lives under). 59 * 60 * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>' 61 * (ie: snapshots) are ZFS nodes and have their own unique vfs_t. 62 * However, vnodes within these mounted on file systems have their v_vfsp 63 * fields set to the head filesystem to make NFS happy (see 64 * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t 65 * so that it cannot be freed until all snapshots have been unmounted. 66 */ 67 68#include <sys/zfs_context.h> 69#include <sys/zfs_ctldir.h> 70#include <sys/zfs_ioctl.h> 71#include <sys/zfs_vfsops.h> 72#include <sys/namei.h> 73#include <sys/gfs.h> 74#include <sys/stat.h> 75#include <sys/dmu.h> 76#include <sys/dsl_destroy.h> 77#include <sys/dsl_deleg.h> 78#include <sys/mount.h> 79#include <sys/sunddi.h> 80 81#include "zfs_namecheck.h" 82 83typedef struct zfsctl_node { 84 gfs_dir_t zc_gfs_private; 85 uint64_t zc_id; 86 timestruc_t zc_cmtime; /* ctime and mtime, always the same */ 87} zfsctl_node_t; 88 89typedef struct zfsctl_snapdir { 90 zfsctl_node_t sd_node; 91 kmutex_t sd_lock; 92 avl_tree_t sd_snaps; 93} zfsctl_snapdir_t; 94 95typedef struct { 96 char *se_name; 97 vnode_t *se_root; 98 avl_node_t se_node; 99} zfs_snapentry_t; 100 101static int 102snapentry_compare(const void *a, const void *b) 103{ 104 const zfs_snapentry_t *sa = a; 105 const zfs_snapentry_t *sb = b; 106 int ret = strcmp(sa->se_name, sb->se_name); 107 108 if (ret < 0) 109 return (-1); 110 else if (ret > 0) 111 return (1); 112 else 113 return (0); 114} 115 116#ifdef illumos 117vnodeops_t *zfsctl_ops_root; 118vnodeops_t *zfsctl_ops_snapdir; 119vnodeops_t *zfsctl_ops_snapshot; 120vnodeops_t *zfsctl_ops_shares; 121vnodeops_t *zfsctl_ops_shares_dir; 122 123static const fs_operation_def_t zfsctl_tops_root[]; 124static const fs_operation_def_t zfsctl_tops_snapdir[]; 125static const fs_operation_def_t zfsctl_tops_snapshot[]; 126static const fs_operation_def_t zfsctl_tops_shares[]; 127#else 128static struct vop_vector zfsctl_ops_root; 129static struct vop_vector zfsctl_ops_snapdir; 130static struct vop_vector zfsctl_ops_snapshot; 131static struct vop_vector zfsctl_ops_shares; 132static struct vop_vector zfsctl_ops_shares_dir; 133#endif 134 135static vnode_t *zfsctl_mknode_snapdir(vnode_t *); 136static vnode_t *zfsctl_mknode_shares(vnode_t *); 137static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset); 138static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *); 139 140#ifdef illumos 141static gfs_opsvec_t zfsctl_opsvec[] = { 142 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root }, 143 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir }, 144 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot }, 145 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir }, 146 { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares }, 147 { NULL } 148}; 149#endif 150 151/* 152 * Root directory elements. We only have two entries 153 * snapshot and shares. 154 */ 155static gfs_dirent_t zfsctl_root_entries[] = { 156 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE }, 157 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE }, 158 { NULL } 159}; 160 161/* include . and .. in the calculation */ 162#define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \ 163 sizeof (gfs_dirent_t)) + 1) 164 165 166/* 167 * Initialize the various GFS pieces we'll need to create and manipulate .zfs 168 * directories. This is called from the ZFS init routine, and initializes the 169 * vnode ops vectors that we'll be using. 170 */ 171void 172zfsctl_init(void) 173{ 174#ifdef illumos 175 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0); 176#endif 177} 178 179void 180zfsctl_fini(void) 181{ 182#ifdef illumos 183 /* 184 * Remove vfsctl vnode ops 185 */ 186 if (zfsctl_ops_root) 187 vn_freevnodeops(zfsctl_ops_root); 188 if (zfsctl_ops_snapdir) 189 vn_freevnodeops(zfsctl_ops_snapdir); 190 if (zfsctl_ops_snapshot) 191 vn_freevnodeops(zfsctl_ops_snapshot); 192 if (zfsctl_ops_shares) 193 vn_freevnodeops(zfsctl_ops_shares); 194 if (zfsctl_ops_shares_dir) 195 vn_freevnodeops(zfsctl_ops_shares_dir); 196 197 zfsctl_ops_root = NULL; 198 zfsctl_ops_snapdir = NULL; 199 zfsctl_ops_snapshot = NULL; 200 zfsctl_ops_shares = NULL; 201 zfsctl_ops_shares_dir = NULL; 202#endif /* illumos */ 203} 204 205boolean_t 206zfsctl_is_node(vnode_t *vp) 207{ 208 return (vn_matchops(vp, zfsctl_ops_root) || 209 vn_matchops(vp, zfsctl_ops_snapdir) || 210 vn_matchops(vp, zfsctl_ops_snapshot) || 211 vn_matchops(vp, zfsctl_ops_shares) || 212 vn_matchops(vp, zfsctl_ops_shares_dir)); 213 214} 215 216/* 217 * Return the inode number associated with the 'snapshot' or 218 * 'shares' directory. 219 */ 220/* ARGSUSED */ 221static ino64_t 222zfsctl_root_inode_cb(vnode_t *vp, int index) 223{ 224 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 225 226 ASSERT(index < 2); 227 228 if (index == 0) 229 return (ZFSCTL_INO_SNAPDIR); 230 231 return (zfsvfs->z_shares_dir); 232} 233 234/* 235 * Create the '.zfs' directory. This directory is cached as part of the VFS 236 * structure. This results in a hold on the vfs_t. The code in zfs_umount() 237 * therefore checks against a vfs_count of 2 instead of 1. This reference 238 * is removed when the ctldir is destroyed in the unmount. 239 */ 240void 241zfsctl_create(zfsvfs_t *zfsvfs) 242{ 243 vnode_t *vp, *rvp; 244 zfsctl_node_t *zcp; 245 uint64_t crtime[2]; 246 247 ASSERT(zfsvfs->z_ctldir == NULL); 248 249 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs, 250 &zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries, 251 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL); 252 zcp = vp->v_data; 253 zcp->zc_id = ZFSCTL_INO_ROOT; 254 255 VERIFY(VFS_ROOT(zfsvfs->z_vfs, LK_EXCLUSIVE, &rvp) == 0); 256 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs), 257 &crtime, sizeof (crtime))); 258 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime); 259 VN_URELE(rvp); 260 261 /* 262 * We're only faking the fact that we have a root of a filesystem for 263 * the sake of the GFS interfaces. Undo the flag manipulation it did 264 * for us. 265 */ 266 vp->v_vflag &= ~VV_ROOT; 267 268 zfsvfs->z_ctldir = vp; 269 270 VOP_UNLOCK(vp, 0); 271} 272 273/* 274 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted. 275 * There might still be more references if we were force unmounted, but only 276 * new zfs_inactive() calls can occur and they don't reference .zfs 277 */ 278void 279zfsctl_destroy(zfsvfs_t *zfsvfs) 280{ 281 VN_RELE(zfsvfs->z_ctldir); 282 zfsvfs->z_ctldir = NULL; 283} 284 285/* 286 * Given a root znode, retrieve the associated .zfs directory. 287 * Add a hold to the vnode and return it. 288 */ 289vnode_t * 290zfsctl_root(znode_t *zp) 291{ 292 ASSERT(zfs_has_ctldir(zp)); 293 VN_HOLD(zp->z_zfsvfs->z_ctldir); 294 return (zp->z_zfsvfs->z_ctldir); 295} 296 297static int 298zfsctl_common_print(ap) 299 struct vop_print_args /* { 300 struct vnode *a_vp; 301 } */ *ap; 302{ 303 vnode_t *vp = ap->a_vp; 304 gfs_file_t *fp = vp->v_data; 305 306 printf(" parent = %p\n", fp->gfs_parent); 307 printf(" type = %d\n", fp->gfs_type); 308 printf(" index = %d\n", fp->gfs_index); 309 printf(" ino = %ju\n", (uintmax_t)fp->gfs_ino); 310 return (0); 311} 312 313/* 314 * Common open routine. Disallow any write access. 315 */ 316/* ARGSUSED */ 317static int 318zfsctl_common_open(struct vop_open_args *ap) 319{ 320 int flags = ap->a_mode; 321 322 if (flags & FWRITE) 323 return (SET_ERROR(EACCES)); 324 325 return (0); 326} 327 328/* 329 * Common close routine. Nothing to do here. 330 */ 331/* ARGSUSED */ 332static int 333zfsctl_common_close(struct vop_close_args *ap) 334{ 335 return (0); 336} 337 338/* 339 * Common access routine. Disallow writes. 340 */ 341/* ARGSUSED */ 342static int 343zfsctl_common_access(ap) 344 struct vop_access_args /* { 345 struct vnode *a_vp; 346 accmode_t a_accmode; 347 struct ucred *a_cred; 348 struct thread *a_td; 349 } */ *ap; 350{ 351 accmode_t accmode = ap->a_accmode; 352 353#ifdef TODO 354 if (flags & V_ACE_MASK) { 355 if (accmode & ACE_ALL_WRITE_PERMS) 356 return (SET_ERROR(EACCES)); 357 } else { 358#endif 359 if (accmode & VWRITE) 360 return (SET_ERROR(EACCES)); 361#ifdef TODO 362 } 363#endif 364 365 return (0); 366} 367 368/* 369 * Common getattr function. Fill in basic information. 370 */ 371static void 372zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) 373{ 374 timestruc_t now; 375 376 vap->va_uid = 0; 377 vap->va_gid = 0; 378 vap->va_rdev = 0; 379 /* 380 * We are a purely virtual object, so we have no 381 * blocksize or allocated blocks. 382 */ 383 vap->va_blksize = 0; 384 vap->va_nblocks = 0; 385 vap->va_seq = 0; 386 vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0]; 387 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | 388 S_IROTH | S_IXOTH; 389 vap->va_type = VDIR; 390 /* 391 * We live in the now (for atime). 392 */ 393 gethrestime(&now); 394 vap->va_atime = now; 395 /* FreeBSD: Reset chflags(2) flags. */ 396 vap->va_flags = 0; 397} 398 399/*ARGSUSED*/ 400static int 401zfsctl_common_fid(ap) 402 struct vop_fid_args /* { 403 struct vnode *a_vp; 404 struct fid *a_fid; 405 } */ *ap; 406{ 407 vnode_t *vp = ap->a_vp; 408 fid_t *fidp = (void *)ap->a_fid; 409 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 410 zfsctl_node_t *zcp = vp->v_data; 411 uint64_t object = zcp->zc_id; 412 zfid_short_t *zfid; 413 int i; 414 415 ZFS_ENTER(zfsvfs); 416 417#ifdef illumos 418 if (fidp->fid_len < SHORT_FID_LEN) { 419 fidp->fid_len = SHORT_FID_LEN; 420 ZFS_EXIT(zfsvfs); 421 return (SET_ERROR(ENOSPC)); 422 } 423#endif 424 425 zfid = (zfid_short_t *)fidp; 426 427 zfid->zf_len = SHORT_FID_LEN; 428 429 for (i = 0; i < sizeof (zfid->zf_object); i++) 430 zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); 431 432 /* .zfs znodes always have a generation number of 0 */ 433 for (i = 0; i < sizeof (zfid->zf_gen); i++) 434 zfid->zf_gen[i] = 0; 435 436 ZFS_EXIT(zfsvfs); 437 return (0); 438} 439 440 441/*ARGSUSED*/ 442static int 443zfsctl_shares_fid(ap) 444 struct vop_fid_args /* { 445 struct vnode *a_vp; 446 struct fid *a_fid; 447 } */ *ap; 448{ 449 vnode_t *vp = ap->a_vp; 450 fid_t *fidp = (void *)ap->a_fid; 451 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 452 znode_t *dzp; 453 int error; 454 455 ZFS_ENTER(zfsvfs); 456 457 if (zfsvfs->z_shares_dir == 0) { 458 ZFS_EXIT(zfsvfs); 459 return (SET_ERROR(ENOTSUP)); 460 } 461 462 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 463 error = VOP_FID(ZTOV(dzp), fidp); 464 VN_RELE(ZTOV(dzp)); 465 } 466 467 ZFS_EXIT(zfsvfs); 468 return (error); 469} 470 471static int 472zfsctl_common_reclaim(ap) 473 struct vop_reclaim_args /* { 474 struct vnode *a_vp; 475 struct thread *a_td; 476 } */ *ap; 477{ 478 vnode_t *vp = ap->a_vp; 479 480 /* 481 * Destroy the vm object and flush associated pages. 482 */ 483 vnode_destroy_vobject(vp); 484 VI_LOCK(vp); 485 vp->v_data = NULL; 486 VI_UNLOCK(vp); 487 return (0); 488} 489 490/* 491 * .zfs inode namespace 492 * 493 * We need to generate unique inode numbers for all files and directories 494 * within the .zfs pseudo-filesystem. We use the following scheme: 495 * 496 * ENTRY ZFSCTL_INODE 497 * .zfs 1 498 * .zfs/snapshot 2 499 * .zfs/snapshot/<snap> objectid(snap) 500 */ 501 502#define ZFSCTL_INO_SNAP(id) (id) 503 504/* 505 * Get root directory attributes. 506 */ 507/* ARGSUSED */ 508static int 509zfsctl_root_getattr(ap) 510 struct vop_getattr_args /* { 511 struct vnode *a_vp; 512 struct vattr *a_vap; 513 struct ucred *a_cred; 514 } */ *ap; 515{ 516 struct vnode *vp = ap->a_vp; 517 struct vattr *vap = ap->a_vap; 518 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 519 zfsctl_node_t *zcp = vp->v_data; 520 521 ZFS_ENTER(zfsvfs); 522 vap->va_nodeid = ZFSCTL_INO_ROOT; 523 vap->va_nlink = vap->va_size = NROOT_ENTRIES; 524 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; 525 vap->va_birthtime = vap->va_ctime; 526 527 zfsctl_common_getattr(vp, vap); 528 ZFS_EXIT(zfsvfs); 529 530 return (0); 531} 532 533/* 534 * Special case the handling of "..". 535 */ 536/* ARGSUSED */ 537int 538zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 539 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 540 int *direntflags, pathname_t *realpnp) 541{ 542 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 543 int err; 544 545 /* 546 * No extended attributes allowed under .zfs 547 */ 548 if (flags & LOOKUP_XATTR) 549 return (SET_ERROR(EINVAL)); 550 551 ZFS_ENTER(zfsvfs); 552 553 if (strcmp(nm, "..") == 0) { 554 err = VFS_ROOT(dvp->v_vfsp, LK_EXCLUSIVE, vpp); 555 if (err == 0) 556 VOP_UNLOCK(*vpp, 0); 557 } else { 558 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, 559 cr, ct, direntflags, realpnp); 560 } 561 562 ZFS_EXIT(zfsvfs); 563 564 return (err); 565} 566 567static int 568zfsctl_root_print(ap) 569 struct vop_print_args /* { 570 struct vnode *a_vp; 571 } */ *ap; 572{ 573 printf(" .zfs node\n"); 574 zfsctl_common_print(ap); 575 return (0); 576} 577 578#ifdef illumos 579static int 580zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, 581 caller_context_t *ct) 582{ 583 /* 584 * We only care about ACL_ENABLED so that libsec can 585 * display ACL correctly and not default to POSIX draft. 586 */ 587 if (cmd == _PC_ACL_ENABLED) { 588 *valp = _ACL_ACE_ENABLED; 589 return (0); 590 } 591 592 return (fs_pathconf(vp, cmd, valp, cr, ct)); 593} 594#endif /* illumos */ 595 596#ifdef illumos 597static const fs_operation_def_t zfsctl_tops_root[] = { 598 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 599 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 600 { VOPNAME_IOCTL, { .error = fs_inval } }, 601 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, 602 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 603 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 604 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, 605 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 606 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 607 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } }, 608 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 609 { NULL } 610}; 611#endif /* illumos */ 612 613/* 614 * Special case the handling of "..". 615 */ 616/* ARGSUSED */ 617int 618zfsctl_freebsd_root_lookup(ap) 619 struct vop_lookup_args /* { 620 struct vnode *a_dvp; 621 struct vnode **a_vpp; 622 struct componentname *a_cnp; 623 } */ *ap; 624{ 625 vnode_t *dvp = ap->a_dvp; 626 vnode_t **vpp = ap->a_vpp; 627 cred_t *cr = ap->a_cnp->cn_cred; 628 int flags = ap->a_cnp->cn_flags; 629 int nameiop = ap->a_cnp->cn_nameiop; 630 char nm[NAME_MAX + 1]; 631 int err; 632 int ltype; 633 634 if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE)) 635 return (EOPNOTSUPP); 636 637 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 638 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 639 err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL); 640 if (err == 0 && (nm[0] != '.' || nm[1] != '\0')) { 641 ltype = VOP_ISLOCKED(dvp); 642 if (flags & ISDOTDOT) { 643 VN_HOLD(*vpp); 644 VOP_UNLOCK(dvp, 0); 645 } 646 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 647 if (flags & ISDOTDOT) { 648 VN_RELE(*vpp); 649 vn_lock(dvp, ltype| LK_RETRY); 650 } 651 } 652 653 return (err); 654} 655 656static struct vop_vector zfsctl_ops_root = { 657 .vop_default = &default_vnodeops, 658 .vop_open = zfsctl_common_open, 659 .vop_close = zfsctl_common_close, 660 .vop_ioctl = VOP_EINVAL, 661 .vop_getattr = zfsctl_root_getattr, 662 .vop_access = zfsctl_common_access, 663 .vop_readdir = gfs_vop_readdir, 664 .vop_lookup = zfsctl_freebsd_root_lookup, 665 .vop_inactive = VOP_NULL, 666 .vop_reclaim = gfs_vop_reclaim, 667#ifdef TODO 668 .vop_pathconf = zfsctl_pathconf, 669#endif 670 .vop_fid = zfsctl_common_fid, 671 .vop_print = zfsctl_root_print, 672}; 673 674/* 675 * Gets the full dataset name that corresponds to the given snapshot name 676 * Example: 677 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1" 678 */ 679static int 680zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) 681{ 682 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; 683 684 if (zfs_component_namecheck(name, NULL, NULL) != 0) 685 return (SET_ERROR(EILSEQ)); 686 dmu_objset_name(os, zname); 687 if (strlen(zname) + 1 + strlen(name) >= len) 688 return (SET_ERROR(ENAMETOOLONG)); 689 (void) strcat(zname, "@"); 690 (void) strcat(zname, name); 691 return (0); 692} 693 694static int 695zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) 696{ 697 vnode_t *svp = sep->se_root; 698 int error; 699 700 ASSERT(vn_ismntpt(svp)); 701 702 /* this will be dropped by dounmount() */ 703 if ((error = vn_vfswlock(svp)) != 0) 704 return (error); 705 706#ifdef illumos 707 VN_HOLD(svp); 708 error = dounmount(vn_mountedvfs(svp), fflags, cr); 709 if (error) { 710 VN_RELE(svp); 711 return (error); 712 } 713 714 /* 715 * We can't use VN_RELE(), as that will try to invoke 716 * zfsctl_snapdir_inactive(), which would cause us to destroy 717 * the sd_lock mutex held by our caller. 718 */ 719 ASSERT(svp->v_count == 1); 720 gfs_vop_reclaim(svp, cr, NULL); 721 722 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 723 kmem_free(sep, sizeof (zfs_snapentry_t)); 724 725 return (0); 726#else 727 vfs_ref(vn_mountedvfs(svp)); 728 return (dounmount(vn_mountedvfs(svp), fflags, curthread)); 729#endif 730} 731 732#ifdef illumos 733static void 734zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) 735{ 736 avl_index_t where; 737 vfs_t *vfsp; 738 refstr_t *pathref; 739 char newpath[MAXNAMELEN]; 740 char *tail; 741 742 ASSERT(MUTEX_HELD(&sdp->sd_lock)); 743 ASSERT(sep != NULL); 744 745 vfsp = vn_mountedvfs(sep->se_root); 746 ASSERT(vfsp != NULL); 747 748 vfs_lock_wait(vfsp); 749 750 /* 751 * Change the name in the AVL tree. 752 */ 753 avl_remove(&sdp->sd_snaps, sep); 754 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 755 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 756 (void) strcpy(sep->se_name, nm); 757 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); 758 avl_insert(&sdp->sd_snaps, sep, where); 759 760 /* 761 * Change the current mountpoint info: 762 * - update the tail of the mntpoint path 763 * - update the tail of the resource path 764 */ 765 pathref = vfs_getmntpoint(vfsp); 766 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 767 VERIFY((tail = strrchr(newpath, '/')) != NULL); 768 *(tail+1) = '\0'; 769 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 770 (void) strcat(newpath, nm); 771 refstr_rele(pathref); 772 vfs_setmntpoint(vfsp, newpath, 0); 773 774 pathref = vfs_getresource(vfsp); 775 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 776 VERIFY((tail = strrchr(newpath, '@')) != NULL); 777 *(tail+1) = '\0'; 778 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 779 (void) strcat(newpath, nm); 780 refstr_rele(pathref); 781 vfs_setresource(vfsp, newpath, 0); 782 783 vfs_unlock(vfsp); 784} 785#endif /* illumos */ 786 787#ifdef illumos 788/*ARGSUSED*/ 789static int 790zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, 791 cred_t *cr, caller_context_t *ct, int flags) 792{ 793 zfsctl_snapdir_t *sdp = sdvp->v_data; 794 zfs_snapentry_t search, *sep; 795 zfsvfs_t *zfsvfs; 796 avl_index_t where; 797 char from[MAXNAMELEN], to[MAXNAMELEN]; 798 char real[MAXNAMELEN], fsname[MAXNAMELEN]; 799 int err; 800 801 zfsvfs = sdvp->v_vfsp->vfs_data; 802 ZFS_ENTER(zfsvfs); 803 804 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 805 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, 806 MAXNAMELEN, NULL); 807 if (err == 0) { 808 snm = real; 809 } else if (err != ENOTSUP) { 810 ZFS_EXIT(zfsvfs); 811 return (err); 812 } 813 } 814 815 ZFS_EXIT(zfsvfs); 816 817 dmu_objset_name(zfsvfs->z_os, fsname); 818 819 err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from); 820 if (err == 0) 821 err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to); 822 if (err == 0) 823 err = zfs_secpolicy_rename_perms(from, to, cr); 824 if (err != 0) 825 return (err); 826 827 /* 828 * Cannot move snapshots out of the snapdir. 829 */ 830 if (sdvp != tdvp) 831 return (SET_ERROR(EINVAL)); 832 833 if (strcmp(snm, tnm) == 0) 834 return (0); 835 836 mutex_enter(&sdp->sd_lock); 837 838 search.se_name = (char *)snm; 839 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { 840 mutex_exit(&sdp->sd_lock); 841 return (SET_ERROR(ENOENT)); 842 } 843 844 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, 0); 845 if (err == 0) 846 zfsctl_rename_snap(sdp, sep, tnm); 847 848 mutex_exit(&sdp->sd_lock); 849 850 return (err); 851} 852#endif /* illumos */ 853 854#ifdef illumos 855/* ARGSUSED */ 856static int 857zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, 858 caller_context_t *ct, int flags) 859{ 860 zfsctl_snapdir_t *sdp = dvp->v_data; 861 zfs_snapentry_t *sep; 862 zfs_snapentry_t search; 863 zfsvfs_t *zfsvfs; 864 char snapname[MAXNAMELEN]; 865 char real[MAXNAMELEN]; 866 int err; 867 868 zfsvfs = dvp->v_vfsp->vfs_data; 869 ZFS_ENTER(zfsvfs); 870 871 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 872 873 err = dmu_snapshot_realname(zfsvfs->z_os, name, real, 874 MAXNAMELEN, NULL); 875 if (err == 0) { 876 name = real; 877 } else if (err != ENOTSUP) { 878 ZFS_EXIT(zfsvfs); 879 return (err); 880 } 881 } 882 883 ZFS_EXIT(zfsvfs); 884 885 err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname); 886 if (err == 0) 887 err = zfs_secpolicy_destroy_perms(snapname, cr); 888 if (err != 0) 889 return (err); 890 891 mutex_enter(&sdp->sd_lock); 892 893 search.se_name = name; 894 sep = avl_find(&sdp->sd_snaps, &search, NULL); 895 if (sep) { 896 avl_remove(&sdp->sd_snaps, sep); 897 err = zfsctl_unmount_snap(sep, MS_FORCE, cr); 898 if (err != 0) 899 avl_add(&sdp->sd_snaps, sep); 900 else 901 err = dsl_destroy_snapshot(snapname, B_FALSE); 902 } else { 903 err = SET_ERROR(ENOENT); 904 } 905 906 mutex_exit(&sdp->sd_lock); 907 908 return (err); 909} 910#endif /* illumos */ 911 912/* 913 * This creates a snapshot under '.zfs/snapshot'. 914 */ 915/* ARGSUSED */ 916static int 917zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, 918 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) 919{ 920 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 921 char name[MAXNAMELEN]; 922 int err; 923 static enum symfollow follow = NO_FOLLOW; 924 static enum uio_seg seg = UIO_SYSSPACE; 925 926 if (zfs_component_namecheck(dirname, NULL, NULL) != 0) 927 return (SET_ERROR(EILSEQ)); 928 929 dmu_objset_name(zfsvfs->z_os, name); 930 931 *vpp = NULL; 932 933 err = zfs_secpolicy_snapshot_perms(name, cr); 934 if (err != 0) 935 return (err); 936 937 if (err == 0) { 938 err = dmu_objset_snapshot_one(name, dirname); 939 if (err != 0) 940 return (err); 941 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); 942 } 943 944 return (err); 945} 946 947static int 948zfsctl_freebsd_snapdir_mkdir(ap) 949 struct vop_mkdir_args /* { 950 struct vnode *a_dvp; 951 struct vnode **a_vpp; 952 struct componentname *a_cnp; 953 struct vattr *a_vap; 954 } */ *ap; 955{ 956 957 ASSERT(ap->a_cnp->cn_flags & SAVENAME); 958 959 return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL, 960 ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL)); 961} 962 963/* 964 * Lookup entry point for the 'snapshot' directory. Try to open the 965 * snapshot if it exist, creating the pseudo filesystem vnode as necessary. 966 * Perform a mount of the associated dataset on top of the vnode. 967 */ 968/* ARGSUSED */ 969int 970zfsctl_snapdir_lookup(ap) 971 struct vop_lookup_args /* { 972 struct vnode *a_dvp; 973 struct vnode **a_vpp; 974 struct componentname *a_cnp; 975 } */ *ap; 976{ 977 vnode_t *dvp = ap->a_dvp; 978 vnode_t **vpp = ap->a_vpp; 979 struct componentname *cnp = ap->a_cnp; 980 char nm[NAME_MAX + 1]; 981 zfsctl_snapdir_t *sdp = dvp->v_data; 982 objset_t *snap; 983 char snapname[MAXNAMELEN]; 984 char real[MAXNAMELEN]; 985 char *mountpoint; 986 zfs_snapentry_t *sep, search; 987 size_t mountpoint_len; 988 avl_index_t where; 989 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 990 int err; 991 int ltype, flags = 0; 992 993 /* 994 * No extended attributes allowed under .zfs 995 */ 996 if (flags & LOOKUP_XATTR) 997 return (SET_ERROR(EINVAL)); 998 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 999 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 1000 1001 ASSERT(dvp->v_type == VDIR); 1002 1003 *vpp = NULL; 1004 1005 /* 1006 * If we get a recursive call, that means we got called 1007 * from the domount() code while it was trying to look up the 1008 * spec (which looks like a local path for zfs). We need to 1009 * add some flag to domount() to tell it not to do this lookup. 1010 */ 1011 if (MUTEX_HELD(&sdp->sd_lock)) 1012 return (SET_ERROR(ENOENT)); 1013 1014 ZFS_ENTER(zfsvfs); 1015 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 1016 ZFS_EXIT(zfsvfs); 1017 return (0); 1018 } 1019 1020 if (flags & FIGNORECASE) { 1021 boolean_t conflict = B_FALSE; 1022 1023 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, 1024 MAXNAMELEN, &conflict); 1025 if (err == 0) { 1026 strlcpy(nm, real, sizeof(nm)); 1027 } else if (err != ENOTSUP) { 1028 ZFS_EXIT(zfsvfs); 1029 return (err); 1030 } 1031#if 0 1032 if (realpnp) 1033 (void) strlcpy(realpnp->pn_buf, nm, 1034 realpnp->pn_bufsize); 1035 if (conflict && direntflags) 1036 *direntflags = ED_CASE_CONFLICT; 1037#endif 1038 } 1039 1040 mutex_enter(&sdp->sd_lock); 1041 search.se_name = (char *)nm; 1042 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { 1043 *vpp = sep->se_root; 1044 VN_HOLD(*vpp); 1045 err = traverse(vpp, LK_EXCLUSIVE | LK_RETRY); 1046 if (err != 0) { 1047 VN_RELE(*vpp); 1048 *vpp = NULL; 1049 } else if (*vpp == sep->se_root) { 1050 /* 1051 * The snapshot was unmounted behind our backs, 1052 * try to remount it. 1053 */ 1054 VERIFY(zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname) == 0); 1055 goto domount; 1056 } else { 1057 /* 1058 * VROOT was set during the traverse call. We need 1059 * to clear it since we're pretending to be part 1060 * of our parent's vfs. 1061 */ 1062 (*vpp)->v_flag &= ~VROOT; 1063 } 1064 mutex_exit(&sdp->sd_lock); 1065 ZFS_EXIT(zfsvfs); 1066 return (err); 1067 } 1068 1069 /* 1070 * The requested snapshot is not currently mounted, look it up. 1071 */ 1072 err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname); 1073 if (err != 0) { 1074 mutex_exit(&sdp->sd_lock); 1075 ZFS_EXIT(zfsvfs); 1076 /* 1077 * handle "ls *" or "?" in a graceful manner, 1078 * forcing EILSEQ to ENOENT. 1079 * Since shell ultimately passes "*" or "?" as name to lookup 1080 */ 1081 return (err == EILSEQ ? ENOENT : err); 1082 } 1083 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) { 1084 mutex_exit(&sdp->sd_lock); 1085#ifdef illumos 1086 ZFS_EXIT(zfsvfs); 1087 return (SET_ERROR(ENOENT)); 1088#else /* !illumos */ 1089 /* Translate errors and add SAVENAME when needed. */ 1090 if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) { 1091 err = EJUSTRETURN; 1092 cnp->cn_flags |= SAVENAME; 1093 } else { 1094 err = SET_ERROR(ENOENT); 1095 } 1096 ZFS_EXIT(zfsvfs); 1097 return (err); 1098#endif /* illumos */ 1099 } 1100 1101 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); 1102 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 1103 (void) strcpy(sep->se_name, nm); 1104 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); 1105 avl_insert(&sdp->sd_snaps, sep, where); 1106 1107 dmu_objset_rele(snap, FTAG); 1108domount: 1109 mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) + 1110 strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1; 1111 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); 1112 (void) snprintf(mountpoint, mountpoint_len, 1113 "%s/" ZFS_CTLDIR_NAME "/snapshot/%s", 1114 dvp->v_vfsp->mnt_stat.f_mntonname, nm); 1115 err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0); 1116 kmem_free(mountpoint, mountpoint_len); 1117 if (err == 0) { 1118 /* 1119 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>. 1120 * 1121 * This is where we lie about our v_vfsp in order to 1122 * make .zfs/snapshot/<snapname> accessible over NFS 1123 * without requiring manual mounts of <snapname>. 1124 */ 1125 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); 1126 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; 1127 } 1128 mutex_exit(&sdp->sd_lock); 1129 ZFS_EXIT(zfsvfs); 1130 1131#ifdef illumos 1132 /* 1133 * If we had an error, drop our hold on the vnode and 1134 * zfsctl_snapshot_inactive() will clean up. 1135 */ 1136 if (err != 0) { 1137 VN_RELE(*vpp); 1138 *vpp = NULL; 1139 } 1140#else 1141 if (err != 0) 1142 *vpp = NULL; 1143#endif 1144 return (err); 1145} 1146 1147/* ARGSUSED */ 1148int 1149zfsctl_shares_lookup(ap) 1150 struct vop_lookup_args /* { 1151 struct vnode *a_dvp; 1152 struct vnode **a_vpp; 1153 struct componentname *a_cnp; 1154 } */ *ap; 1155{ 1156 vnode_t *dvp = ap->a_dvp; 1157 vnode_t **vpp = ap->a_vpp; 1158 struct componentname *cnp = ap->a_cnp; 1159 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1160 char nm[NAME_MAX + 1]; 1161 znode_t *dzp; 1162 int error; 1163 1164 ZFS_ENTER(zfsvfs); 1165 1166 ASSERT(cnp->cn_namelen < sizeof(nm)); 1167 strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1); 1168 1169 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 1170 ZFS_EXIT(zfsvfs); 1171 return (0); 1172 } 1173 1174 if (zfsvfs->z_shares_dir == 0) { 1175 ZFS_EXIT(zfsvfs); 1176 return (SET_ERROR(ENOTSUP)); 1177 } 1178 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1179 error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp); 1180 VN_RELE(ZTOV(dzp)); 1181 } 1182 1183 ZFS_EXIT(zfsvfs); 1184 1185 return (error); 1186} 1187 1188/* ARGSUSED */ 1189static int 1190zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, 1191 offset_t *offp, offset_t *nextp, void *data, int flags) 1192{ 1193 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1194 char snapname[MAXNAMELEN]; 1195 uint64_t id, cookie; 1196 boolean_t case_conflict; 1197 int error; 1198 1199 ZFS_ENTER(zfsvfs); 1200 1201 cookie = *offp; 1202 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); 1203 error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id, 1204 &cookie, &case_conflict); 1205 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); 1206 if (error) { 1207 ZFS_EXIT(zfsvfs); 1208 if (error == ENOENT) { 1209 *eofp = 1; 1210 return (0); 1211 } 1212 return (error); 1213 } 1214 1215 if (flags & V_RDDIR_ENTFLAGS) { 1216 edirent_t *eodp = dp; 1217 1218 (void) strcpy(eodp->ed_name, snapname); 1219 eodp->ed_ino = ZFSCTL_INO_SNAP(id); 1220 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; 1221 } else { 1222 struct dirent64 *odp = dp; 1223 1224 (void) strcpy(odp->d_name, snapname); 1225 odp->d_ino = ZFSCTL_INO_SNAP(id); 1226 } 1227 *nextp = cookie; 1228 1229 ZFS_EXIT(zfsvfs); 1230 1231 return (0); 1232} 1233 1234/* ARGSUSED */ 1235static int 1236zfsctl_shares_readdir(ap) 1237 struct vop_readdir_args /* { 1238 struct vnode *a_vp; 1239 struct uio *a_uio; 1240 struct ucred *a_cred; 1241 int *a_eofflag; 1242 int *a_ncookies; 1243 u_long **a_cookies; 1244 } */ *ap; 1245{ 1246 vnode_t *vp = ap->a_vp; 1247 uio_t *uiop = ap->a_uio; 1248 cred_t *cr = ap->a_cred; 1249 int *eofp = ap->a_eofflag; 1250 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1251 znode_t *dzp; 1252 int error; 1253 1254 ZFS_ENTER(zfsvfs); 1255 1256 if (zfsvfs->z_shares_dir == 0) { 1257 ZFS_EXIT(zfsvfs); 1258 return (SET_ERROR(ENOTSUP)); 1259 } 1260 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1261 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1262 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies); 1263 VN_URELE(ZTOV(dzp)); 1264 } else { 1265 *eofp = 1; 1266 error = SET_ERROR(ENOENT); 1267 } 1268 1269 ZFS_EXIT(zfsvfs); 1270 return (error); 1271} 1272 1273/* 1274 * pvp is the '.zfs' directory (zfsctl_node_t). 1275 * 1276 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). 1277 * 1278 * This function is the callback to create a GFS vnode for '.zfs/snapshot' 1279 * when a lookup is performed on .zfs for "snapshot". 1280 */ 1281vnode_t * 1282zfsctl_mknode_snapdir(vnode_t *pvp) 1283{ 1284 vnode_t *vp; 1285 zfsctl_snapdir_t *sdp; 1286 1287 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, pvp->v_vfsp, 1288 &zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, 1289 zfsctl_snapdir_readdir_cb, NULL); 1290 sdp = vp->v_data; 1291 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; 1292 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1293 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 1294 avl_create(&sdp->sd_snaps, snapentry_compare, 1295 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); 1296 VOP_UNLOCK(vp, 0); 1297 return (vp); 1298} 1299 1300vnode_t * 1301zfsctl_mknode_shares(vnode_t *pvp) 1302{ 1303 vnode_t *vp; 1304 zfsctl_node_t *sdp; 1305 1306 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1307 &zfsctl_ops_shares, NULL, NULL, MAXNAMELEN, 1308 NULL, NULL); 1309 sdp = vp->v_data; 1310 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1311 VOP_UNLOCK(vp, 0); 1312 return (vp); 1313 1314} 1315 1316/* ARGSUSED */ 1317static int 1318zfsctl_shares_getattr(ap) 1319 struct vop_getattr_args /* { 1320 struct vnode *a_vp; 1321 struct vattr *a_vap; 1322 struct ucred *a_cred; 1323 struct thread *a_td; 1324 } */ *ap; 1325{ 1326 vnode_t *vp = ap->a_vp; 1327 vattr_t *vap = ap->a_vap; 1328 cred_t *cr = ap->a_cred; 1329 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1330 znode_t *dzp; 1331 int error; 1332 1333 ZFS_ENTER(zfsvfs); 1334 if (zfsvfs->z_shares_dir == 0) { 1335 ZFS_EXIT(zfsvfs); 1336 return (SET_ERROR(ENOTSUP)); 1337 } 1338 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1339 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1340 error = VOP_GETATTR(ZTOV(dzp), vap, cr); 1341 VN_URELE(ZTOV(dzp)); 1342 } 1343 ZFS_EXIT(zfsvfs); 1344 return (error); 1345 1346 1347} 1348 1349/* ARGSUSED */ 1350static int 1351zfsctl_snapdir_getattr(ap) 1352 struct vop_getattr_args /* { 1353 struct vnode *a_vp; 1354 struct vattr *a_vap; 1355 struct ucred *a_cred; 1356 } */ *ap; 1357{ 1358 vnode_t *vp = ap->a_vp; 1359 vattr_t *vap = ap->a_vap; 1360 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1361 zfsctl_snapdir_t *sdp = vp->v_data; 1362 1363 ZFS_ENTER(zfsvfs); 1364 zfsctl_common_getattr(vp, vap); 1365 vap->va_nodeid = gfs_file_inode(vp); 1366 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; 1367 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); 1368 vap->va_birthtime = vap->va_ctime; 1369 ZFS_EXIT(zfsvfs); 1370 1371 return (0); 1372} 1373 1374/* ARGSUSED */ 1375static int 1376zfsctl_snapdir_inactive(ap) 1377 struct vop_inactive_args /* { 1378 struct vnode *a_vp; 1379 struct thread *a_td; 1380 } */ *ap; 1381{ 1382 vnode_t *vp = ap->a_vp; 1383 zfsctl_snapdir_t *sdp = vp->v_data; 1384 zfs_snapentry_t *sep; 1385 1386 /* 1387 * On forced unmount we have to free snapshots from here. 1388 */ 1389 mutex_enter(&sdp->sd_lock); 1390 while ((sep = avl_first(&sdp->sd_snaps)) != NULL) { 1391 avl_remove(&sdp->sd_snaps, sep); 1392 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1393 kmem_free(sep, sizeof (zfs_snapentry_t)); 1394 } 1395 mutex_exit(&sdp->sd_lock); 1396 gfs_dir_inactive(vp); 1397 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); 1398 mutex_destroy(&sdp->sd_lock); 1399 avl_destroy(&sdp->sd_snaps); 1400 kmem_free(sdp, sizeof (zfsctl_snapdir_t)); 1401 1402 return (0); 1403} 1404 1405static int 1406zfsctl_shares_print(ap) 1407 struct vop_print_args /* { 1408 struct vnode *a_vp; 1409 } */ *ap; 1410{ 1411 printf(" .zfs/shares node\n"); 1412 zfsctl_common_print(ap); 1413 return (0); 1414} 1415 1416static int 1417zfsctl_snapdir_print(ap) 1418 struct vop_print_args /* { 1419 struct vnode *a_vp; 1420 } */ *ap; 1421{ 1422 vnode_t *vp = ap->a_vp; 1423 zfsctl_snapdir_t *sdp = vp->v_data; 1424 1425 printf(" .zfs/snapshot node\n"); 1426 printf(" number of children = %lu\n", avl_numnodes(&sdp->sd_snaps)); 1427 zfsctl_common_print(ap); 1428 return (0); 1429} 1430 1431#ifdef illumos 1432static const fs_operation_def_t zfsctl_tops_snapdir[] = { 1433 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1434 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1435 { VOPNAME_IOCTL, { .error = fs_inval } }, 1436 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, 1437 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1438 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, 1439 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, 1440 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, 1441 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 1442 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, 1443 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1444 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, 1445 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 1446 { NULL } 1447}; 1448 1449static const fs_operation_def_t zfsctl_tops_shares[] = { 1450 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1451 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1452 { VOPNAME_IOCTL, { .error = fs_inval } }, 1453 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } }, 1454 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1455 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } }, 1456 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } }, 1457 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1458 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 1459 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } }, 1460 { NULL } 1461}; 1462#else /* !illumos */ 1463static struct vop_vector zfsctl_ops_snapdir = { 1464 .vop_default = &default_vnodeops, 1465 .vop_open = zfsctl_common_open, 1466 .vop_close = zfsctl_common_close, 1467 .vop_ioctl = VOP_EINVAL, 1468 .vop_getattr = zfsctl_snapdir_getattr, 1469 .vop_access = zfsctl_common_access, 1470 .vop_mkdir = zfsctl_freebsd_snapdir_mkdir, 1471 .vop_readdir = gfs_vop_readdir, 1472 .vop_lookup = zfsctl_snapdir_lookup, 1473 .vop_inactive = zfsctl_snapdir_inactive, 1474 .vop_reclaim = zfsctl_common_reclaim, 1475 .vop_fid = zfsctl_common_fid, 1476 .vop_print = zfsctl_snapdir_print, 1477}; 1478 1479static struct vop_vector zfsctl_ops_shares = { 1480 .vop_default = &default_vnodeops, 1481 .vop_open = zfsctl_common_open, 1482 .vop_close = zfsctl_common_close, 1483 .vop_ioctl = VOP_EINVAL, 1484 .vop_getattr = zfsctl_shares_getattr, 1485 .vop_access = zfsctl_common_access, 1486 .vop_readdir = zfsctl_shares_readdir, 1487 .vop_lookup = zfsctl_shares_lookup, 1488 .vop_inactive = VOP_NULL, 1489 .vop_reclaim = gfs_vop_reclaim, 1490 .vop_fid = zfsctl_shares_fid, 1491 .vop_print = zfsctl_shares_print, 1492}; 1493#endif /* illumos */ 1494 1495/* 1496 * pvp is the GFS vnode '.zfs/snapshot'. 1497 * 1498 * This creates a GFS node under '.zfs/snapshot' representing each 1499 * snapshot. This newly created GFS node is what we mount snapshot 1500 * vfs_t's ontop of. 1501 */ 1502static vnode_t * 1503zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) 1504{ 1505 vnode_t *vp; 1506 zfsctl_node_t *zcp; 1507 1508 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1509 &zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); 1510 zcp = vp->v_data; 1511 zcp->zc_id = objset; 1512 VOP_UNLOCK(vp, 0); 1513 1514 return (vp); 1515} 1516 1517 1518static int 1519zfsctl_snapshot_reclaim(ap) 1520 struct vop_inactive_args /* { 1521 struct vnode *a_vp; 1522 struct thread *a_td; 1523 } */ *ap; 1524{ 1525 vnode_t *vp = ap->a_vp; 1526 cred_t *cr = ap->a_td->td_ucred; 1527 struct vop_reclaim_args iap; 1528 zfsctl_snapdir_t *sdp; 1529 zfs_snapentry_t *sep, *next; 1530 int locked; 1531 vnode_t *dvp; 1532 1533 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); 1534 sdp = dvp->v_data; 1535 VOP_UNLOCK(dvp, 0); 1536 /* this may already have been unmounted */ 1537 if (sdp == NULL) { 1538 VN_RELE(dvp); 1539 return (0); 1540 } 1541 if (!(locked = MUTEX_HELD(&sdp->sd_lock))) 1542 mutex_enter(&sdp->sd_lock); 1543 1544 ASSERT(!vn_ismntpt(vp)); 1545 1546 sep = avl_first(&sdp->sd_snaps); 1547 while (sep != NULL) { 1548 next = AVL_NEXT(&sdp->sd_snaps, sep); 1549 1550 if (sep->se_root == vp) { 1551 avl_remove(&sdp->sd_snaps, sep); 1552 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1553 kmem_free(sep, sizeof (zfs_snapentry_t)); 1554 break; 1555 } 1556 sep = next; 1557 } 1558 ASSERT(sep != NULL); 1559 1560 if (!locked) 1561 mutex_exit(&sdp->sd_lock); 1562 VN_RELE(dvp); 1563 1564 /* 1565 * Dispose of the vnode for the snapshot mount point. 1566 * This is safe to do because once this entry has been removed 1567 * from the AVL tree, it can't be found again, so cannot become 1568 * "active". If we lookup the same name again we will end up 1569 * creating a new vnode. 1570 */ 1571 iap.a_vp = vp; 1572 gfs_vop_reclaim(&iap); 1573 return (0); 1574 1575} 1576 1577static int 1578zfsctl_traverse_begin(vnode_t **vpp, int lktype) 1579{ 1580 1581 VN_HOLD(*vpp); 1582 /* Snapshot should be already mounted, but just in case. */ 1583 if (vn_mountedvfs(*vpp) == NULL) 1584 return (ENOENT); 1585 return (traverse(vpp, lktype)); 1586} 1587 1588static void 1589zfsctl_traverse_end(vnode_t *vp, int err) 1590{ 1591 1592 if (err == 0) 1593 vput(vp); 1594 else 1595 VN_RELE(vp); 1596} 1597 1598static int 1599zfsctl_snapshot_getattr(ap) 1600 struct vop_getattr_args /* { 1601 struct vnode *a_vp; 1602 struct vattr *a_vap; 1603 struct ucred *a_cred; 1604 } */ *ap; 1605{ 1606 vnode_t *vp = ap->a_vp; 1607 int err; 1608 1609 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1610 if (err == 0) 1611 err = VOP_GETATTR(vp, ap->a_vap, ap->a_cred); 1612 zfsctl_traverse_end(vp, err); 1613 return (err); 1614} 1615 1616static int 1617zfsctl_snapshot_fid(ap) 1618 struct vop_fid_args /* { 1619 struct vnode *a_vp; 1620 struct fid *a_fid; 1621 } */ *ap; 1622{ 1623 vnode_t *vp = ap->a_vp; 1624 int err; 1625 1626 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1627 if (err == 0) 1628 err = VOP_VPTOFH(vp, (void *)ap->a_fid); 1629 zfsctl_traverse_end(vp, err); 1630 return (err); 1631} 1632 1633static int 1634zfsctl_snapshot_lookup(ap) 1635 struct vop_lookup_args /* { 1636 struct vnode *a_dvp; 1637 struct vnode **a_vpp; 1638 struct componentname *a_cnp; 1639 } */ *ap; 1640{ 1641 vnode_t *dvp = ap->a_dvp; 1642 vnode_t **vpp = ap->a_vpp; 1643 struct componentname *cnp = ap->a_cnp; 1644 cred_t *cr = ap->a_cnp->cn_cred; 1645 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1646 int error; 1647 1648 if (cnp->cn_namelen != 2 || cnp->cn_nameptr[0] != '.' || 1649 cnp->cn_nameptr[1] != '.') { 1650 return (ENOENT); 1651 } 1652 1653 ASSERT(dvp->v_type == VDIR); 1654 ASSERT(zfsvfs->z_ctldir != NULL); 1655 1656 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", vpp, 1657 NULL, 0, NULL, cr, NULL, NULL, NULL); 1658 if (error == 0) { 1659 int ltype = VOP_ISLOCKED(dvp); 1660 VN_HOLD(*vpp); 1661 VOP_UNLOCK(dvp, 0); 1662 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 1663 VN_RELE(*vpp); 1664 vn_lock(dvp, ltype | LK_RETRY); 1665 } 1666 1667 return (error); 1668} 1669 1670static int 1671zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap) 1672{ 1673 zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data; 1674 vnode_t *dvp, *vp; 1675 zfsctl_snapdir_t *sdp; 1676 zfs_snapentry_t *sep; 1677 int error; 1678 1679 ASSERT(zfsvfs->z_ctldir != NULL); 1680 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1681 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1682 if (error != 0) 1683 return (error); 1684 sdp = dvp->v_data; 1685 1686 mutex_enter(&sdp->sd_lock); 1687 sep = avl_first(&sdp->sd_snaps); 1688 while (sep != NULL) { 1689 vp = sep->se_root; 1690 if (vp == ap->a_vp) 1691 break; 1692 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1693 } 1694 if (sep == NULL) { 1695 mutex_exit(&sdp->sd_lock); 1696 error = ENOENT; 1697 } else { 1698 size_t len; 1699 1700 len = strlen(sep->se_name); 1701 *ap->a_buflen -= len; 1702 bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len); 1703 mutex_exit(&sdp->sd_lock); 1704 vref(dvp); 1705 *ap->a_vpp = dvp; 1706 } 1707 VN_RELE(dvp); 1708 1709 return (error); 1710} 1711 1712static int 1713zfsctl_snaphot_print(ap) 1714 struct vop_print_args /* { 1715 struct vnode *a_vp; 1716 } */ *ap; 1717{ 1718 vnode_t *vp = ap->a_vp; 1719 zfsctl_node_t *zcp = vp->v_data; 1720 1721 printf(" .zfs/snapshot/<snap> node\n"); 1722 printf(" id = %ju\n", (uintmax_t)zcp->zc_id); 1723 zfsctl_common_print(ap); 1724 return (0); 1725} 1726 1727/* 1728 * These VP's should never see the light of day. They should always 1729 * be covered. 1730 */ 1731static struct vop_vector zfsctl_ops_snapshot = { 1732 .vop_default = &default_vnodeops, 1733 .vop_inactive = VOP_NULL, 1734 .vop_lookup = zfsctl_snapshot_lookup, 1735 .vop_reclaim = zfsctl_snapshot_reclaim, 1736 .vop_getattr = zfsctl_snapshot_getattr, 1737 .vop_fid = zfsctl_snapshot_fid, 1738 .vop_vptocnp = zfsctl_snapshot_vptocnp, 1739 .vop_print = zfsctl_snaphot_print, 1740}; 1741 1742int 1743zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) 1744{ 1745 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1746 vnode_t *dvp, *vp; 1747 zfsctl_snapdir_t *sdp; 1748 zfsctl_node_t *zcp; 1749 zfs_snapentry_t *sep; 1750 int error; 1751 1752 ASSERT(zfsvfs->z_ctldir != NULL); 1753 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1754 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1755 if (error != 0) 1756 return (error); 1757 sdp = dvp->v_data; 1758 1759 mutex_enter(&sdp->sd_lock); 1760 sep = avl_first(&sdp->sd_snaps); 1761 while (sep != NULL) { 1762 vp = sep->se_root; 1763 zcp = vp->v_data; 1764 if (zcp->zc_id == objsetid) 1765 break; 1766 1767 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1768 } 1769 1770 if (sep != NULL) { 1771 VN_HOLD(vp); 1772 /* 1773 * Return the mounted root rather than the covered mount point. 1774 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> 1775 * and returns the ZFS vnode mounted on top of the GFS node. 1776 * This ZFS vnode is the root of the vfs for objset 'objsetid'. 1777 */ 1778 error = traverse(&vp, LK_SHARED | LK_RETRY); 1779 if (error == 0) { 1780 if (vp == sep->se_root) 1781 error = SET_ERROR(EINVAL); 1782 else 1783 *zfsvfsp = VTOZ(vp)->z_zfsvfs; 1784 } 1785 mutex_exit(&sdp->sd_lock); 1786 if (error == 0) 1787 VN_URELE(vp); 1788 else 1789 VN_RELE(vp); 1790 } else { 1791 error = SET_ERROR(EINVAL); 1792 mutex_exit(&sdp->sd_lock); 1793 } 1794 1795 VN_RELE(dvp); 1796 1797 return (error); 1798} 1799 1800/* 1801 * Unmount any snapshots for the given filesystem. This is called from 1802 * zfs_umount() - if we have a ctldir, then go through and unmount all the 1803 * snapshots. 1804 */ 1805int 1806zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) 1807{ 1808 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1809 vnode_t *dvp; 1810 zfsctl_snapdir_t *sdp; 1811 zfs_snapentry_t *sep, *next; 1812 int error; 1813 1814 ASSERT(zfsvfs->z_ctldir != NULL); 1815 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1816 NULL, 0, NULL, cr, NULL, NULL, NULL); 1817 if (error != 0) 1818 return (error); 1819 sdp = dvp->v_data; 1820 1821 mutex_enter(&sdp->sd_lock); 1822 1823 sep = avl_first(&sdp->sd_snaps); 1824 while (sep != NULL) { 1825 next = AVL_NEXT(&sdp->sd_snaps, sep); 1826 1827 /* 1828 * If this snapshot is not mounted, then it must 1829 * have just been unmounted by somebody else, and 1830 * will be cleaned up by zfsctl_snapdir_inactive(). 1831 */ 1832 if (vn_ismntpt(sep->se_root)) { 1833 error = zfsctl_unmount_snap(sep, fflags, cr); 1834 if (error) { 1835 avl_index_t where; 1836 1837 /* 1838 * Before reinserting snapshot to the tree, 1839 * check if it was actually removed. For example 1840 * when snapshot mount point is busy, we will 1841 * have an error here, but there will be no need 1842 * to reinsert snapshot. 1843 */ 1844 if (avl_find(&sdp->sd_snaps, sep, &where) == NULL) 1845 avl_insert(&sdp->sd_snaps, sep, where); 1846 break; 1847 } 1848 } 1849 sep = next; 1850 } 1851 1852 mutex_exit(&sdp->sd_lock); 1853 VN_RELE(dvp); 1854 1855 return (error); 1856} 1857