zfs_ctldir.c revision 297077
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} 296 297/* 298 * Common open routine. Disallow any write access. 299 */ 300/* ARGSUSED */ 301static int 302zfsctl_common_open(struct vop_open_args *ap) 303{ 304 int flags = ap->a_mode; 305 306 if (flags & FWRITE) 307 return (SET_ERROR(EACCES)); 308 309 return (0); 310} 311 312/* 313 * Common close routine. Nothing to do here. 314 */ 315/* ARGSUSED */ 316static int 317zfsctl_common_close(struct vop_close_args *ap) 318{ 319 return (0); 320} 321 322/* 323 * Common access routine. Disallow writes. 324 */ 325/* ARGSUSED */ 326static int 327zfsctl_common_access(ap) 328 struct vop_access_args /* { 329 struct vnode *a_vp; 330 accmode_t a_accmode; 331 struct ucred *a_cred; 332 struct thread *a_td; 333 } */ *ap; 334{ 335 accmode_t accmode = ap->a_accmode; 336 337#ifdef TODO 338 if (flags & V_ACE_MASK) { 339 if (accmode & ACE_ALL_WRITE_PERMS) 340 return (SET_ERROR(EACCES)); 341 } else { 342#endif 343 if (accmode & VWRITE) 344 return (SET_ERROR(EACCES)); 345#ifdef TODO 346 } 347#endif 348 349 return (0); 350} 351 352/* 353 * Common getattr function. Fill in basic information. 354 */ 355static void 356zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) 357{ 358 timestruc_t now; 359 360 vap->va_uid = 0; 361 vap->va_gid = 0; 362 vap->va_rdev = 0; 363 /* 364 * We are a purely virtual object, so we have no 365 * blocksize or allocated blocks. 366 */ 367 vap->va_blksize = 0; 368 vap->va_nblocks = 0; 369 vap->va_seq = 0; 370 vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0]; 371 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | 372 S_IROTH | S_IXOTH; 373 vap->va_type = VDIR; 374 /* 375 * We live in the now (for atime). 376 */ 377 gethrestime(&now); 378 vap->va_atime = now; 379 /* FreeBSD: Reset chflags(2) flags. */ 380 vap->va_flags = 0; 381} 382 383/*ARGSUSED*/ 384static int 385zfsctl_common_fid(ap) 386 struct vop_fid_args /* { 387 struct vnode *a_vp; 388 struct fid *a_fid; 389 } */ *ap; 390{ 391 vnode_t *vp = ap->a_vp; 392 fid_t *fidp = (void *)ap->a_fid; 393 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 394 zfsctl_node_t *zcp = vp->v_data; 395 uint64_t object = zcp->zc_id; 396 zfid_short_t *zfid; 397 int i; 398 399 ZFS_ENTER(zfsvfs); 400 401#ifdef illumos 402 if (fidp->fid_len < SHORT_FID_LEN) { 403 fidp->fid_len = SHORT_FID_LEN; 404 ZFS_EXIT(zfsvfs); 405 return (SET_ERROR(ENOSPC)); 406 } 407#else 408 fidp->fid_len = SHORT_FID_LEN; 409#endif 410 411 zfid = (zfid_short_t *)fidp; 412 413 zfid->zf_len = SHORT_FID_LEN; 414 415 for (i = 0; i < sizeof (zfid->zf_object); i++) 416 zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); 417 418 /* .zfs znodes always have a generation number of 0 */ 419 for (i = 0; i < sizeof (zfid->zf_gen); i++) 420 zfid->zf_gen[i] = 0; 421 422 ZFS_EXIT(zfsvfs); 423 return (0); 424} 425 426 427/*ARGSUSED*/ 428static int 429zfsctl_shares_fid(ap) 430 struct vop_fid_args /* { 431 struct vnode *a_vp; 432 struct fid *a_fid; 433 } */ *ap; 434{ 435 vnode_t *vp = ap->a_vp; 436 fid_t *fidp = (void *)ap->a_fid; 437 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 438 znode_t *dzp; 439 int error; 440 441 ZFS_ENTER(zfsvfs); 442 443 if (zfsvfs->z_shares_dir == 0) { 444 ZFS_EXIT(zfsvfs); 445 return (SET_ERROR(ENOTSUP)); 446 } 447 448 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 449 error = VOP_FID(ZTOV(dzp), fidp); 450 VN_RELE(ZTOV(dzp)); 451 } 452 453 ZFS_EXIT(zfsvfs); 454 return (error); 455} 456 457static int 458zfsctl_common_reclaim(ap) 459 struct vop_reclaim_args /* { 460 struct vnode *a_vp; 461 struct thread *a_td; 462 } */ *ap; 463{ 464 vnode_t *vp = ap->a_vp; 465 466 /* 467 * Destroy the vm object and flush associated pages. 468 */ 469 vnode_destroy_vobject(vp); 470 VI_LOCK(vp); 471 vp->v_data = NULL; 472 VI_UNLOCK(vp); 473 return (0); 474} 475 476/* 477 * .zfs inode namespace 478 * 479 * We need to generate unique inode numbers for all files and directories 480 * within the .zfs pseudo-filesystem. We use the following scheme: 481 * 482 * ENTRY ZFSCTL_INODE 483 * .zfs 1 484 * .zfs/snapshot 2 485 * .zfs/snapshot/<snap> objectid(snap) 486 */ 487 488#define ZFSCTL_INO_SNAP(id) (id) 489 490/* 491 * Get root directory attributes. 492 */ 493/* ARGSUSED */ 494static int 495zfsctl_root_getattr(ap) 496 struct vop_getattr_args /* { 497 struct vnode *a_vp; 498 struct vattr *a_vap; 499 struct ucred *a_cred; 500 } */ *ap; 501{ 502 struct vnode *vp = ap->a_vp; 503 struct vattr *vap = ap->a_vap; 504 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 505 zfsctl_node_t *zcp = vp->v_data; 506 507 ZFS_ENTER(zfsvfs); 508 vap->va_nodeid = ZFSCTL_INO_ROOT; 509 vap->va_nlink = vap->va_size = NROOT_ENTRIES; 510 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; 511 vap->va_birthtime = vap->va_ctime; 512 513 zfsctl_common_getattr(vp, vap); 514 ZFS_EXIT(zfsvfs); 515 516 return (0); 517} 518 519/* 520 * Special case the handling of "..". 521 */ 522/* ARGSUSED */ 523int 524zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 525 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 526 int *direntflags, pathname_t *realpnp) 527{ 528 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 529 int err; 530 531 /* 532 * No extended attributes allowed under .zfs 533 */ 534 if (flags & LOOKUP_XATTR) 535 return (SET_ERROR(EINVAL)); 536 537 ZFS_ENTER(zfsvfs); 538 539 if (strcmp(nm, "..") == 0) { 540 err = VFS_ROOT(dvp->v_vfsp, LK_EXCLUSIVE, vpp); 541 if (err == 0) 542 VOP_UNLOCK(*vpp, 0); 543 } else { 544 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, 545 cr, ct, direntflags, realpnp); 546 } 547 548 ZFS_EXIT(zfsvfs); 549 550 return (err); 551} 552 553#ifdef illumos 554static int 555zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, 556 caller_context_t *ct) 557{ 558 /* 559 * We only care about ACL_ENABLED so that libsec can 560 * display ACL correctly and not default to POSIX draft. 561 */ 562 if (cmd == _PC_ACL_ENABLED) { 563 *valp = _ACL_ACE_ENABLED; 564 return (0); 565 } 566 567 return (fs_pathconf(vp, cmd, valp, cr, ct)); 568} 569#endif /* illumos */ 570 571#ifdef illumos 572static const fs_operation_def_t zfsctl_tops_root[] = { 573 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 574 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 575 { VOPNAME_IOCTL, { .error = fs_inval } }, 576 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, 577 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 578 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 579 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, 580 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 581 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 582 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } }, 583 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 584 { NULL } 585}; 586#endif /* illumos */ 587 588/* 589 * Special case the handling of "..". 590 */ 591/* ARGSUSED */ 592int 593zfsctl_freebsd_root_lookup(ap) 594 struct vop_lookup_args /* { 595 struct vnode *a_dvp; 596 struct vnode **a_vpp; 597 struct componentname *a_cnp; 598 } */ *ap; 599{ 600 vnode_t *dvp = ap->a_dvp; 601 vnode_t **vpp = ap->a_vpp; 602 cred_t *cr = ap->a_cnp->cn_cred; 603 int flags = ap->a_cnp->cn_flags; 604 int nameiop = ap->a_cnp->cn_nameiop; 605 char nm[NAME_MAX + 1]; 606 int err; 607 int ltype; 608 609 if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE)) 610 return (EOPNOTSUPP); 611 612 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 613 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 614 err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL); 615 if (err == 0 && (nm[0] != '.' || nm[1] != '\0')) { 616 ltype = VOP_ISLOCKED(dvp); 617 if (flags & ISDOTDOT) { 618 VN_HOLD(*vpp); 619 VOP_UNLOCK(dvp, 0); 620 } 621 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 622 if (flags & ISDOTDOT) { 623 VN_RELE(*vpp); 624 vn_lock(dvp, ltype| LK_RETRY); 625 } 626 } 627 628 return (err); 629} 630 631static struct vop_vector zfsctl_ops_root = { 632 .vop_default = &default_vnodeops, 633 .vop_open = zfsctl_common_open, 634 .vop_close = zfsctl_common_close, 635 .vop_ioctl = VOP_EINVAL, 636 .vop_getattr = zfsctl_root_getattr, 637 .vop_access = zfsctl_common_access, 638 .vop_readdir = gfs_vop_readdir, 639 .vop_lookup = zfsctl_freebsd_root_lookup, 640 .vop_inactive = VOP_NULL, 641 .vop_reclaim = gfs_vop_reclaim, 642#ifdef TODO 643 .vop_pathconf = zfsctl_pathconf, 644#endif 645 .vop_fid = zfsctl_common_fid, 646}; 647 648/* 649 * Gets the full dataset name that corresponds to the given snapshot name 650 * Example: 651 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1" 652 */ 653static int 654zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) 655{ 656 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; 657 658 if (zfs_component_namecheck(name, NULL, NULL) != 0) 659 return (SET_ERROR(EILSEQ)); 660 dmu_objset_name(os, zname); 661 if (strlen(zname) + 1 + strlen(name) >= len) 662 return (SET_ERROR(ENAMETOOLONG)); 663 (void) strcat(zname, "@"); 664 (void) strcat(zname, name); 665 return (0); 666} 667 668static int 669zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) 670{ 671 vnode_t *svp = sep->se_root; 672 int error; 673 674 ASSERT(vn_ismntpt(svp)); 675 676 /* this will be dropped by dounmount() */ 677 if ((error = vn_vfswlock(svp)) != 0) 678 return (error); 679 680#ifdef illumos 681 VN_HOLD(svp); 682 error = dounmount(vn_mountedvfs(svp), fflags, cr); 683 if (error) { 684 VN_RELE(svp); 685 return (error); 686 } 687 688 /* 689 * We can't use VN_RELE(), as that will try to invoke 690 * zfsctl_snapdir_inactive(), which would cause us to destroy 691 * the sd_lock mutex held by our caller. 692 */ 693 ASSERT(svp->v_count == 1); 694 gfs_vop_reclaim(svp, cr, NULL); 695 696 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 697 kmem_free(sep, sizeof (zfs_snapentry_t)); 698 699 return (0); 700#else 701 vfs_ref(vn_mountedvfs(svp)); 702 return (dounmount(vn_mountedvfs(svp), fflags, curthread)); 703#endif 704} 705 706#ifdef illumos 707static void 708zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) 709{ 710 avl_index_t where; 711 vfs_t *vfsp; 712 refstr_t *pathref; 713 char newpath[MAXNAMELEN]; 714 char *tail; 715 716 ASSERT(MUTEX_HELD(&sdp->sd_lock)); 717 ASSERT(sep != NULL); 718 719 vfsp = vn_mountedvfs(sep->se_root); 720 ASSERT(vfsp != NULL); 721 722 vfs_lock_wait(vfsp); 723 724 /* 725 * Change the name in the AVL tree. 726 */ 727 avl_remove(&sdp->sd_snaps, sep); 728 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 729 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 730 (void) strcpy(sep->se_name, nm); 731 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); 732 avl_insert(&sdp->sd_snaps, sep, where); 733 734 /* 735 * Change the current mountpoint info: 736 * - update the tail of the mntpoint path 737 * - update the tail of the resource path 738 */ 739 pathref = vfs_getmntpoint(vfsp); 740 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 741 VERIFY((tail = strrchr(newpath, '/')) != NULL); 742 *(tail+1) = '\0'; 743 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 744 (void) strcat(newpath, nm); 745 refstr_rele(pathref); 746 vfs_setmntpoint(vfsp, newpath, 0); 747 748 pathref = vfs_getresource(vfsp); 749 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 750 VERIFY((tail = strrchr(newpath, '@')) != NULL); 751 *(tail+1) = '\0'; 752 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 753 (void) strcat(newpath, nm); 754 refstr_rele(pathref); 755 vfs_setresource(vfsp, newpath, 0); 756 757 vfs_unlock(vfsp); 758} 759#endif /* illumos */ 760 761#ifdef illumos 762/*ARGSUSED*/ 763static int 764zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, 765 cred_t *cr, caller_context_t *ct, int flags) 766{ 767 zfsctl_snapdir_t *sdp = sdvp->v_data; 768 zfs_snapentry_t search, *sep; 769 zfsvfs_t *zfsvfs; 770 avl_index_t where; 771 char from[MAXNAMELEN], to[MAXNAMELEN]; 772 char real[MAXNAMELEN], fsname[MAXNAMELEN]; 773 int err; 774 775 zfsvfs = sdvp->v_vfsp->vfs_data; 776 ZFS_ENTER(zfsvfs); 777 778 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 779 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, 780 MAXNAMELEN, NULL); 781 if (err == 0) { 782 snm = real; 783 } else if (err != ENOTSUP) { 784 ZFS_EXIT(zfsvfs); 785 return (err); 786 } 787 } 788 789 ZFS_EXIT(zfsvfs); 790 791 dmu_objset_name(zfsvfs->z_os, fsname); 792 793 err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from); 794 if (err == 0) 795 err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to); 796 if (err == 0) 797 err = zfs_secpolicy_rename_perms(from, to, cr); 798 if (err != 0) 799 return (err); 800 801 /* 802 * Cannot move snapshots out of the snapdir. 803 */ 804 if (sdvp != tdvp) 805 return (SET_ERROR(EINVAL)); 806 807 if (strcmp(snm, tnm) == 0) 808 return (0); 809 810 mutex_enter(&sdp->sd_lock); 811 812 search.se_name = (char *)snm; 813 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { 814 mutex_exit(&sdp->sd_lock); 815 return (SET_ERROR(ENOENT)); 816 } 817 818 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, 0); 819 if (err == 0) 820 zfsctl_rename_snap(sdp, sep, tnm); 821 822 mutex_exit(&sdp->sd_lock); 823 824 return (err); 825} 826#endif /* illumos */ 827 828#ifdef illumos 829/* ARGSUSED */ 830static int 831zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, 832 caller_context_t *ct, int flags) 833{ 834 zfsctl_snapdir_t *sdp = dvp->v_data; 835 zfs_snapentry_t *sep; 836 zfs_snapentry_t search; 837 zfsvfs_t *zfsvfs; 838 char snapname[MAXNAMELEN]; 839 char real[MAXNAMELEN]; 840 int err; 841 842 zfsvfs = dvp->v_vfsp->vfs_data; 843 ZFS_ENTER(zfsvfs); 844 845 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 846 847 err = dmu_snapshot_realname(zfsvfs->z_os, name, real, 848 MAXNAMELEN, NULL); 849 if (err == 0) { 850 name = real; 851 } else if (err != ENOTSUP) { 852 ZFS_EXIT(zfsvfs); 853 return (err); 854 } 855 } 856 857 ZFS_EXIT(zfsvfs); 858 859 err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname); 860 if (err == 0) 861 err = zfs_secpolicy_destroy_perms(snapname, cr); 862 if (err != 0) 863 return (err); 864 865 mutex_enter(&sdp->sd_lock); 866 867 search.se_name = name; 868 sep = avl_find(&sdp->sd_snaps, &search, NULL); 869 if (sep) { 870 avl_remove(&sdp->sd_snaps, sep); 871 err = zfsctl_unmount_snap(sep, MS_FORCE, cr); 872 if (err != 0) 873 avl_add(&sdp->sd_snaps, sep); 874 else 875 err = dsl_destroy_snapshot(snapname, B_FALSE); 876 } else { 877 err = SET_ERROR(ENOENT); 878 } 879 880 mutex_exit(&sdp->sd_lock); 881 882 return (err); 883} 884#endif /* illumos */ 885 886/* 887 * This creates a snapshot under '.zfs/snapshot'. 888 */ 889/* ARGSUSED */ 890static int 891zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, 892 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) 893{ 894 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 895 char name[MAXNAMELEN]; 896 int err; 897 static enum symfollow follow = NO_FOLLOW; 898 static enum uio_seg seg = UIO_SYSSPACE; 899 900 if (zfs_component_namecheck(dirname, NULL, NULL) != 0) 901 return (SET_ERROR(EILSEQ)); 902 903 dmu_objset_name(zfsvfs->z_os, name); 904 905 *vpp = NULL; 906 907 err = zfs_secpolicy_snapshot_perms(name, cr); 908 if (err != 0) 909 return (err); 910 911 if (err == 0) { 912 err = dmu_objset_snapshot_one(name, dirname); 913 if (err != 0) 914 return (err); 915 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); 916 } 917 918 return (err); 919} 920 921static int 922zfsctl_freebsd_snapdir_mkdir(ap) 923 struct vop_mkdir_args /* { 924 struct vnode *a_dvp; 925 struct vnode **a_vpp; 926 struct componentname *a_cnp; 927 struct vattr *a_vap; 928 } */ *ap; 929{ 930 931 ASSERT(ap->a_cnp->cn_flags & SAVENAME); 932 933 return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL, 934 ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL)); 935} 936 937/* 938 * Lookup entry point for the 'snapshot' directory. Try to open the 939 * snapshot if it exist, creating the pseudo filesystem vnode as necessary. 940 * Perform a mount of the associated dataset on top of the vnode. 941 */ 942/* ARGSUSED */ 943int 944zfsctl_snapdir_lookup(ap) 945 struct vop_lookup_args /* { 946 struct vnode *a_dvp; 947 struct vnode **a_vpp; 948 struct componentname *a_cnp; 949 } */ *ap; 950{ 951 vnode_t *dvp = ap->a_dvp; 952 vnode_t **vpp = ap->a_vpp; 953 struct componentname *cnp = ap->a_cnp; 954 char nm[NAME_MAX + 1]; 955 zfsctl_snapdir_t *sdp = dvp->v_data; 956 objset_t *snap; 957 char snapname[MAXNAMELEN]; 958 char real[MAXNAMELEN]; 959 char *mountpoint; 960 zfs_snapentry_t *sep, search; 961 size_t mountpoint_len; 962 avl_index_t where; 963 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 964 int err; 965 int ltype, flags = 0; 966 967 /* 968 * No extended attributes allowed under .zfs 969 */ 970 if (flags & LOOKUP_XATTR) 971 return (SET_ERROR(EINVAL)); 972 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 973 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 974 975 ASSERT(dvp->v_type == VDIR); 976 977 *vpp = NULL; 978 979 /* 980 * If we get a recursive call, that means we got called 981 * from the domount() code while it was trying to look up the 982 * spec (which looks like a local path for zfs). We need to 983 * add some flag to domount() to tell it not to do this lookup. 984 */ 985 if (MUTEX_HELD(&sdp->sd_lock)) 986 return (SET_ERROR(ENOENT)); 987 988 ZFS_ENTER(zfsvfs); 989 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 990 ZFS_EXIT(zfsvfs); 991 return (0); 992 } 993 994 if (flags & FIGNORECASE) { 995 boolean_t conflict = B_FALSE; 996 997 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, 998 MAXNAMELEN, &conflict); 999 if (err == 0) { 1000 strlcpy(nm, real, sizeof(nm)); 1001 } else if (err != ENOTSUP) { 1002 ZFS_EXIT(zfsvfs); 1003 return (err); 1004 } 1005#if 0 1006 if (realpnp) 1007 (void) strlcpy(realpnp->pn_buf, nm, 1008 realpnp->pn_bufsize); 1009 if (conflict && direntflags) 1010 *direntflags = ED_CASE_CONFLICT; 1011#endif 1012 } 1013 1014 mutex_enter(&sdp->sd_lock); 1015 search.se_name = (char *)nm; 1016 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { 1017 *vpp = sep->se_root; 1018 VN_HOLD(*vpp); 1019 err = traverse(vpp, LK_EXCLUSIVE | LK_RETRY); 1020 if (err != 0) { 1021 VN_RELE(*vpp); 1022 *vpp = NULL; 1023 } else if (*vpp == sep->se_root) { 1024 /* 1025 * The snapshot was unmounted behind our backs, 1026 * try to remount it. 1027 */ 1028 VERIFY(zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname) == 0); 1029 goto domount; 1030 } else { 1031 /* 1032 * VROOT was set during the traverse call. We need 1033 * to clear it since we're pretending to be part 1034 * of our parent's vfs. 1035 */ 1036 (*vpp)->v_flag &= ~VROOT; 1037 } 1038 mutex_exit(&sdp->sd_lock); 1039 ZFS_EXIT(zfsvfs); 1040 return (err); 1041 } 1042 1043 /* 1044 * The requested snapshot is not currently mounted, look it up. 1045 */ 1046 err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname); 1047 if (err != 0) { 1048 mutex_exit(&sdp->sd_lock); 1049 ZFS_EXIT(zfsvfs); 1050 /* 1051 * handle "ls *" or "?" in a graceful manner, 1052 * forcing EILSEQ to ENOENT. 1053 * Since shell ultimately passes "*" or "?" as name to lookup 1054 */ 1055 return (err == EILSEQ ? ENOENT : err); 1056 } 1057 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) { 1058 mutex_exit(&sdp->sd_lock); 1059#ifdef illumos 1060 ZFS_EXIT(zfsvfs); 1061 return (SET_ERROR(ENOENT)); 1062#else /* !illumos */ 1063 /* Translate errors and add SAVENAME when needed. */ 1064 if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) { 1065 err = EJUSTRETURN; 1066 cnp->cn_flags |= SAVENAME; 1067 } else { 1068 err = SET_ERROR(ENOENT); 1069 } 1070 ZFS_EXIT(zfsvfs); 1071 return (err); 1072#endif /* illumos */ 1073 } 1074 1075 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); 1076 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 1077 (void) strcpy(sep->se_name, nm); 1078 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); 1079 VN_HOLD(*vpp); 1080 avl_insert(&sdp->sd_snaps, sep, where); 1081 1082 dmu_objset_rele(snap, FTAG); 1083domount: 1084 mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) + 1085 strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1; 1086 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); 1087 (void) snprintf(mountpoint, mountpoint_len, 1088 "%s/" ZFS_CTLDIR_NAME "/snapshot/%s", 1089 dvp->v_vfsp->mnt_stat.f_mntonname, nm); 1090 err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0); 1091 kmem_free(mountpoint, mountpoint_len); 1092 if (err == 0) { 1093 /* 1094 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>. 1095 * 1096 * This is where we lie about our v_vfsp in order to 1097 * make .zfs/snapshot/<snapname> accessible over NFS 1098 * without requiring manual mounts of <snapname>. 1099 */ 1100 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); 1101 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; 1102 } 1103 mutex_exit(&sdp->sd_lock); 1104 ZFS_EXIT(zfsvfs); 1105 1106#ifdef illumos 1107 /* 1108 * If we had an error, drop our hold on the vnode and 1109 * zfsctl_snapshot_inactive() will clean up. 1110 */ 1111 if (err != 0) { 1112 VN_RELE(*vpp); 1113 *vpp = NULL; 1114 } 1115#else 1116 if (err != 0) 1117 *vpp = NULL; 1118#endif 1119 return (err); 1120} 1121 1122/* ARGSUSED */ 1123int 1124zfsctl_shares_lookup(ap) 1125 struct vop_lookup_args /* { 1126 struct vnode *a_dvp; 1127 struct vnode **a_vpp; 1128 struct componentname *a_cnp; 1129 } */ *ap; 1130{ 1131 vnode_t *dvp = ap->a_dvp; 1132 vnode_t **vpp = ap->a_vpp; 1133 struct componentname *cnp = ap->a_cnp; 1134 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1135 char nm[NAME_MAX + 1]; 1136 znode_t *dzp; 1137 int error; 1138 1139 ZFS_ENTER(zfsvfs); 1140 1141 ASSERT(cnp->cn_namelen < sizeof(nm)); 1142 strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1); 1143 1144 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 1145 ZFS_EXIT(zfsvfs); 1146 return (0); 1147 } 1148 1149 if (zfsvfs->z_shares_dir == 0) { 1150 ZFS_EXIT(zfsvfs); 1151 return (SET_ERROR(ENOTSUP)); 1152 } 1153 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1154 error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp); 1155 VN_RELE(ZTOV(dzp)); 1156 } 1157 1158 ZFS_EXIT(zfsvfs); 1159 1160 return (error); 1161} 1162 1163/* ARGSUSED */ 1164static int 1165zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, 1166 offset_t *offp, offset_t *nextp, void *data, int flags) 1167{ 1168 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1169 char snapname[MAXNAMELEN]; 1170 uint64_t id, cookie; 1171 boolean_t case_conflict; 1172 int error; 1173 1174 ZFS_ENTER(zfsvfs); 1175 1176 cookie = *offp; 1177 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); 1178 error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id, 1179 &cookie, &case_conflict); 1180 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); 1181 if (error) { 1182 ZFS_EXIT(zfsvfs); 1183 if (error == ENOENT) { 1184 *eofp = 1; 1185 return (0); 1186 } 1187 return (error); 1188 } 1189 1190 if (flags & V_RDDIR_ENTFLAGS) { 1191 edirent_t *eodp = dp; 1192 1193 (void) strcpy(eodp->ed_name, snapname); 1194 eodp->ed_ino = ZFSCTL_INO_SNAP(id); 1195 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; 1196 } else { 1197 struct dirent64 *odp = dp; 1198 1199 (void) strcpy(odp->d_name, snapname); 1200 odp->d_ino = ZFSCTL_INO_SNAP(id); 1201 } 1202 *nextp = cookie; 1203 1204 ZFS_EXIT(zfsvfs); 1205 1206 return (0); 1207} 1208 1209/* ARGSUSED */ 1210static int 1211zfsctl_shares_readdir(ap) 1212 struct vop_readdir_args /* { 1213 struct vnode *a_vp; 1214 struct uio *a_uio; 1215 struct ucred *a_cred; 1216 int *a_eofflag; 1217 int *a_ncookies; 1218 u_long **a_cookies; 1219 } */ *ap; 1220{ 1221 vnode_t *vp = ap->a_vp; 1222 uio_t *uiop = ap->a_uio; 1223 cred_t *cr = ap->a_cred; 1224 int *eofp = ap->a_eofflag; 1225 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1226 znode_t *dzp; 1227 int error; 1228 1229 ZFS_ENTER(zfsvfs); 1230 1231 if (zfsvfs->z_shares_dir == 0) { 1232 ZFS_EXIT(zfsvfs); 1233 return (SET_ERROR(ENOTSUP)); 1234 } 1235 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1236 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1237 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies); 1238 VN_URELE(ZTOV(dzp)); 1239 } else { 1240 *eofp = 1; 1241 error = SET_ERROR(ENOENT); 1242 } 1243 1244 ZFS_EXIT(zfsvfs); 1245 return (error); 1246} 1247 1248/* 1249 * pvp is the '.zfs' directory (zfsctl_node_t). 1250 * 1251 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). 1252 * 1253 * This function is the callback to create a GFS vnode for '.zfs/snapshot' 1254 * when a lookup is performed on .zfs for "snapshot". 1255 */ 1256vnode_t * 1257zfsctl_mknode_snapdir(vnode_t *pvp) 1258{ 1259 vnode_t *vp; 1260 zfsctl_snapdir_t *sdp; 1261 1262 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, pvp->v_vfsp, 1263 &zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, 1264 zfsctl_snapdir_readdir_cb, NULL); 1265 sdp = vp->v_data; 1266 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; 1267 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1268 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 1269 avl_create(&sdp->sd_snaps, snapentry_compare, 1270 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); 1271 VOP_UNLOCK(vp, 0); 1272 return (vp); 1273} 1274 1275vnode_t * 1276zfsctl_mknode_shares(vnode_t *pvp) 1277{ 1278 vnode_t *vp; 1279 zfsctl_node_t *sdp; 1280 1281 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1282 &zfsctl_ops_shares, NULL, NULL, MAXNAMELEN, 1283 NULL, NULL); 1284 sdp = vp->v_data; 1285 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1286 VOP_UNLOCK(vp, 0); 1287 return (vp); 1288 1289} 1290 1291/* ARGSUSED */ 1292static int 1293zfsctl_shares_getattr(ap) 1294 struct vop_getattr_args /* { 1295 struct vnode *a_vp; 1296 struct vattr *a_vap; 1297 struct ucred *a_cred; 1298 struct thread *a_td; 1299 } */ *ap; 1300{ 1301 vnode_t *vp = ap->a_vp; 1302 vattr_t *vap = ap->a_vap; 1303 cred_t *cr = ap->a_cred; 1304 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1305 znode_t *dzp; 1306 int error; 1307 1308 ZFS_ENTER(zfsvfs); 1309 if (zfsvfs->z_shares_dir == 0) { 1310 ZFS_EXIT(zfsvfs); 1311 return (SET_ERROR(ENOTSUP)); 1312 } 1313 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1314 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1315 error = VOP_GETATTR(ZTOV(dzp), vap, cr); 1316 VN_URELE(ZTOV(dzp)); 1317 } 1318 ZFS_EXIT(zfsvfs); 1319 return (error); 1320 1321 1322} 1323 1324/* ARGSUSED */ 1325static int 1326zfsctl_snapdir_getattr(ap) 1327 struct vop_getattr_args /* { 1328 struct vnode *a_vp; 1329 struct vattr *a_vap; 1330 struct ucred *a_cred; 1331 } */ *ap; 1332{ 1333 vnode_t *vp = ap->a_vp; 1334 vattr_t *vap = ap->a_vap; 1335 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1336 zfsctl_snapdir_t *sdp = vp->v_data; 1337 1338 ZFS_ENTER(zfsvfs); 1339 zfsctl_common_getattr(vp, vap); 1340 vap->va_nodeid = gfs_file_inode(vp); 1341 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; 1342 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); 1343 vap->va_birthtime = vap->va_ctime; 1344 ZFS_EXIT(zfsvfs); 1345 1346 return (0); 1347} 1348 1349/* ARGSUSED */ 1350static int 1351zfsctl_snapdir_inactive(ap) 1352 struct vop_inactive_args /* { 1353 struct vnode *a_vp; 1354 struct thread *a_td; 1355 } */ *ap; 1356{ 1357 vnode_t *vp = ap->a_vp; 1358 zfsctl_snapdir_t *sdp = vp->v_data; 1359 zfs_snapentry_t *sep; 1360 1361 /* 1362 * On forced unmount we have to free snapshots from here. 1363 */ 1364 mutex_enter(&sdp->sd_lock); 1365 while ((sep = avl_first(&sdp->sd_snaps)) != NULL) { 1366 avl_remove(&sdp->sd_snaps, sep); 1367 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1368 kmem_free(sep, sizeof (zfs_snapentry_t)); 1369 } 1370 mutex_exit(&sdp->sd_lock); 1371 gfs_dir_inactive(vp); 1372 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); 1373 mutex_destroy(&sdp->sd_lock); 1374 avl_destroy(&sdp->sd_snaps); 1375 kmem_free(sdp, sizeof (zfsctl_snapdir_t)); 1376 1377 return (0); 1378} 1379 1380#ifdef illumos 1381static const fs_operation_def_t zfsctl_tops_snapdir[] = { 1382 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1383 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1384 { VOPNAME_IOCTL, { .error = fs_inval } }, 1385 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, 1386 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1387 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, 1388 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, 1389 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, 1390 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 1391 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, 1392 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1393 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, 1394 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 1395 { NULL } 1396}; 1397 1398static const fs_operation_def_t zfsctl_tops_shares[] = { 1399 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1400 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1401 { VOPNAME_IOCTL, { .error = fs_inval } }, 1402 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } }, 1403 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1404 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } }, 1405 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } }, 1406 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1407 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 1408 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } }, 1409 { NULL } 1410}; 1411#else /* !illumos */ 1412static struct vop_vector zfsctl_ops_snapdir = { 1413 .vop_default = &default_vnodeops, 1414 .vop_open = zfsctl_common_open, 1415 .vop_close = zfsctl_common_close, 1416 .vop_ioctl = VOP_EINVAL, 1417 .vop_getattr = zfsctl_snapdir_getattr, 1418 .vop_access = zfsctl_common_access, 1419 .vop_mkdir = zfsctl_freebsd_snapdir_mkdir, 1420 .vop_readdir = gfs_vop_readdir, 1421 .vop_lookup = zfsctl_snapdir_lookup, 1422 .vop_inactive = zfsctl_snapdir_inactive, 1423 .vop_reclaim = zfsctl_common_reclaim, 1424 .vop_fid = zfsctl_common_fid, 1425}; 1426 1427static struct vop_vector zfsctl_ops_shares = { 1428 .vop_default = &default_vnodeops, 1429 .vop_open = zfsctl_common_open, 1430 .vop_close = zfsctl_common_close, 1431 .vop_ioctl = VOP_EINVAL, 1432 .vop_getattr = zfsctl_shares_getattr, 1433 .vop_access = zfsctl_common_access, 1434 .vop_readdir = zfsctl_shares_readdir, 1435 .vop_lookup = zfsctl_shares_lookup, 1436 .vop_inactive = VOP_NULL, 1437 .vop_reclaim = gfs_vop_reclaim, 1438 .vop_fid = zfsctl_shares_fid, 1439}; 1440#endif /* illumos */ 1441 1442/* 1443 * pvp is the GFS vnode '.zfs/snapshot'. 1444 * 1445 * This creates a GFS node under '.zfs/snapshot' representing each 1446 * snapshot. This newly created GFS node is what we mount snapshot 1447 * vfs_t's ontop of. 1448 */ 1449static vnode_t * 1450zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) 1451{ 1452 vnode_t *vp; 1453 zfsctl_node_t *zcp; 1454 1455 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1456 &zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); 1457 VN_HOLD(vp); 1458 zcp = vp->v_data; 1459 zcp->zc_id = objset; 1460 VOP_UNLOCK(vp, 0); 1461 1462 return (vp); 1463} 1464 1465 1466static int 1467zfsctl_snapshot_reclaim(ap) 1468 struct vop_inactive_args /* { 1469 struct vnode *a_vp; 1470 struct thread *a_td; 1471 } */ *ap; 1472{ 1473 vnode_t *vp = ap->a_vp; 1474 cred_t *cr = ap->a_td->td_ucred; 1475 struct vop_reclaim_args iap; 1476 zfsctl_snapdir_t *sdp; 1477 zfs_snapentry_t *sep, *next; 1478 int locked; 1479 vnode_t *dvp; 1480 1481 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); 1482 sdp = dvp->v_data; 1483 VOP_UNLOCK(dvp, 0); 1484 /* this may already have been unmounted */ 1485 if (sdp == NULL) { 1486 VN_RELE(dvp); 1487 return (0); 1488 } 1489 if (!(locked = MUTEX_HELD(&sdp->sd_lock))) 1490 mutex_enter(&sdp->sd_lock); 1491 1492 ASSERT(!vn_ismntpt(vp)); 1493 1494 sep = avl_first(&sdp->sd_snaps); 1495 while (sep != NULL) { 1496 next = AVL_NEXT(&sdp->sd_snaps, sep); 1497 1498 if (sep->se_root == vp) { 1499 avl_remove(&sdp->sd_snaps, sep); 1500 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1501 kmem_free(sep, sizeof (zfs_snapentry_t)); 1502 break; 1503 } 1504 sep = next; 1505 } 1506 ASSERT(sep != NULL); 1507 1508 if (!locked) 1509 mutex_exit(&sdp->sd_lock); 1510 VN_RELE(dvp); 1511 1512 /* 1513 * Dispose of the vnode for the snapshot mount point. 1514 * This is safe to do because once this entry has been removed 1515 * from the AVL tree, it can't be found again, so cannot become 1516 * "active". If we lookup the same name again we will end up 1517 * creating a new vnode. 1518 */ 1519 iap.a_vp = vp; 1520 gfs_vop_reclaim(&iap); 1521 return (0); 1522 1523} 1524 1525static int 1526zfsctl_traverse_begin(vnode_t **vpp, int lktype) 1527{ 1528 1529 VN_HOLD(*vpp); 1530 /* Snapshot should be already mounted, but just in case. */ 1531 if (vn_mountedvfs(*vpp) == NULL) 1532 return (ENOENT); 1533 return (traverse(vpp, lktype)); 1534} 1535 1536static void 1537zfsctl_traverse_end(vnode_t *vp, int err) 1538{ 1539 1540 if (err == 0) 1541 vput(vp); 1542 else 1543 VN_RELE(vp); 1544} 1545 1546static int 1547zfsctl_snapshot_getattr(ap) 1548 struct vop_getattr_args /* { 1549 struct vnode *a_vp; 1550 struct vattr *a_vap; 1551 struct ucred *a_cred; 1552 } */ *ap; 1553{ 1554 vnode_t *vp = ap->a_vp; 1555 int err; 1556 1557 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1558 if (err == 0) 1559 err = VOP_GETATTR(vp, ap->a_vap, ap->a_cred); 1560 zfsctl_traverse_end(vp, err); 1561 return (err); 1562} 1563 1564static int 1565zfsctl_snapshot_fid(ap) 1566 struct vop_fid_args /* { 1567 struct vnode *a_vp; 1568 struct fid *a_fid; 1569 } */ *ap; 1570{ 1571 vnode_t *vp = ap->a_vp; 1572 int err; 1573 1574 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1575 if (err == 0) 1576 err = VOP_VPTOFH(vp, (void *)ap->a_fid); 1577 zfsctl_traverse_end(vp, err); 1578 return (err); 1579} 1580 1581static int 1582zfsctl_snapshot_lookup(ap) 1583 struct vop_lookup_args /* { 1584 struct vnode *a_dvp; 1585 struct vnode **a_vpp; 1586 struct componentname *a_cnp; 1587 } */ *ap; 1588{ 1589 vnode_t *dvp = ap->a_dvp; 1590 vnode_t **vpp = ap->a_vpp; 1591 struct componentname *cnp = ap->a_cnp; 1592 cred_t *cr = ap->a_cnp->cn_cred; 1593 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1594 int error; 1595 1596 if (cnp->cn_namelen != 2 || cnp->cn_nameptr[0] != '.' || 1597 cnp->cn_nameptr[1] != '.') { 1598 return (ENOENT); 1599 } 1600 1601 ASSERT(dvp->v_type == VDIR); 1602 ASSERT(zfsvfs->z_ctldir != NULL); 1603 1604 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", vpp, 1605 NULL, 0, NULL, cr, NULL, NULL, NULL); 1606 if (error == 0) { 1607 int ltype = VOP_ISLOCKED(dvp); 1608 VN_HOLD(*vpp); 1609 VOP_UNLOCK(dvp, 0); 1610 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 1611 VN_RELE(*vpp); 1612 vn_lock(dvp, ltype | LK_RETRY); 1613 } 1614 1615 return (error); 1616} 1617 1618static int 1619zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap) 1620{ 1621 zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data; 1622 vnode_t *dvp, *vp; 1623 zfsctl_snapdir_t *sdp; 1624 zfs_snapentry_t *sep; 1625 int error; 1626 1627 ASSERT(zfsvfs->z_ctldir != NULL); 1628 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1629 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1630 if (error != 0) 1631 return (error); 1632 sdp = dvp->v_data; 1633 1634 mutex_enter(&sdp->sd_lock); 1635 sep = avl_first(&sdp->sd_snaps); 1636 while (sep != NULL) { 1637 vp = sep->se_root; 1638 if (vp == ap->a_vp) 1639 break; 1640 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1641 } 1642 if (sep == NULL) { 1643 mutex_exit(&sdp->sd_lock); 1644 error = ENOENT; 1645 } else { 1646 size_t len; 1647 1648 len = strlen(sep->se_name); 1649 *ap->a_buflen -= len; 1650 bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len); 1651 mutex_exit(&sdp->sd_lock); 1652 vref(dvp); 1653 *ap->a_vpp = dvp; 1654 } 1655 VN_RELE(dvp); 1656 1657 return (error); 1658} 1659 1660/* 1661 * These VP's should never see the light of day. They should always 1662 * be covered. 1663 */ 1664static struct vop_vector zfsctl_ops_snapshot = { 1665 .vop_default = &default_vnodeops, 1666 .vop_inactive = VOP_NULL, 1667 .vop_lookup = zfsctl_snapshot_lookup, 1668 .vop_reclaim = zfsctl_snapshot_reclaim, 1669 .vop_getattr = zfsctl_snapshot_getattr, 1670 .vop_fid = zfsctl_snapshot_fid, 1671 .vop_vptocnp = zfsctl_snapshot_vptocnp, 1672}; 1673 1674int 1675zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) 1676{ 1677 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1678 vnode_t *dvp, *vp; 1679 zfsctl_snapdir_t *sdp; 1680 zfsctl_node_t *zcp; 1681 zfs_snapentry_t *sep; 1682 int error; 1683 1684 ASSERT(zfsvfs->z_ctldir != NULL); 1685 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1686 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1687 if (error != 0) 1688 return (error); 1689 sdp = dvp->v_data; 1690 1691 mutex_enter(&sdp->sd_lock); 1692 sep = avl_first(&sdp->sd_snaps); 1693 while (sep != NULL) { 1694 vp = sep->se_root; 1695 zcp = vp->v_data; 1696 if (zcp->zc_id == objsetid) 1697 break; 1698 1699 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1700 } 1701 1702 if (sep != NULL) { 1703 VN_HOLD(vp); 1704 /* 1705 * Return the mounted root rather than the covered mount point. 1706 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> 1707 * and returns the ZFS vnode mounted on top of the GFS node. 1708 * This ZFS vnode is the root of the vfs for objset 'objsetid'. 1709 */ 1710 error = traverse(&vp, LK_SHARED | LK_RETRY); 1711 if (error == 0) { 1712 if (vp == sep->se_root) 1713 error = SET_ERROR(EINVAL); 1714 else 1715 *zfsvfsp = VTOZ(vp)->z_zfsvfs; 1716 } 1717 mutex_exit(&sdp->sd_lock); 1718 if (error == 0) 1719 VN_URELE(vp); 1720 else 1721 VN_RELE(vp); 1722 } else { 1723 error = SET_ERROR(EINVAL); 1724 mutex_exit(&sdp->sd_lock); 1725 } 1726 1727 VN_RELE(dvp); 1728 1729 return (error); 1730} 1731 1732/* 1733 * Unmount any snapshots for the given filesystem. This is called from 1734 * zfs_umount() - if we have a ctldir, then go through and unmount all the 1735 * snapshots. 1736 */ 1737int 1738zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) 1739{ 1740 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1741 vnode_t *dvp; 1742 zfsctl_snapdir_t *sdp; 1743 zfs_snapentry_t *sep, *next; 1744 int error; 1745 1746 ASSERT(zfsvfs->z_ctldir != NULL); 1747 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1748 NULL, 0, NULL, cr, NULL, NULL, NULL); 1749 if (error != 0) 1750 return (error); 1751 sdp = dvp->v_data; 1752 1753 mutex_enter(&sdp->sd_lock); 1754 1755 sep = avl_first(&sdp->sd_snaps); 1756 while (sep != NULL) { 1757 next = AVL_NEXT(&sdp->sd_snaps, sep); 1758 1759 /* 1760 * If this snapshot is not mounted, then it must 1761 * have just been unmounted by somebody else, and 1762 * will be cleaned up by zfsctl_snapdir_inactive(). 1763 */ 1764 if (vn_ismntpt(sep->se_root)) { 1765 error = zfsctl_unmount_snap(sep, fflags, cr); 1766 if (error) { 1767 avl_index_t where; 1768 1769 /* 1770 * Before reinserting snapshot to the tree, 1771 * check if it was actually removed. For example 1772 * when snapshot mount point is busy, we will 1773 * have an error here, but there will be no need 1774 * to reinsert snapshot. 1775 */ 1776 if (avl_find(&sdp->sd_snaps, sep, &where) == NULL) 1777 avl_insert(&sdp->sd_snaps, sep, where); 1778 break; 1779 } 1780 } 1781 sep = next; 1782 } 1783 1784 mutex_exit(&sdp->sd_lock); 1785 VN_RELE(dvp); 1786 1787 return (error); 1788} 1789