zfs_ctldir.c revision 225736
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 */ 24 25/* 26 * ZFS control directory (a.k.a. ".zfs") 27 * 28 * This directory provides a common location for all ZFS meta-objects. 29 * Currently, this is only the 'snapshot' directory, but this may expand in the 30 * future. The elements are built using the GFS primitives, as the hierarchy 31 * does not actually exist on disk. 32 * 33 * For 'snapshot', we don't want to have all snapshots always mounted, because 34 * this would take up a huge amount of space in /etc/mnttab. We have three 35 * types of objects: 36 * 37 * ctldir ------> snapshotdir -------> snapshot 38 * | 39 * | 40 * V 41 * mounted fs 42 * 43 * The 'snapshot' node contains just enough information to lookup '..' and act 44 * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we 45 * perform an automount of the underlying filesystem and return the 46 * corresponding vnode. 47 * 48 * All mounts are handled automatically by the kernel, but unmounts are 49 * (currently) handled from user land. The main reason is that there is no 50 * reliable way to auto-unmount the filesystem when it's "no longer in use". 51 * When the user unmounts a filesystem, we call zfsctl_unmount(), which 52 * unmounts any snapshots within the snapshot directory. 53 * 54 * The '.zfs', '.zfs/snapshot', and all directories created under 55 * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and 56 * share the same vfs_t as the head filesystem (what '.zfs' lives under). 57 * 58 * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>' 59 * (ie: snapshots) are ZFS nodes and have their own unique vfs_t. 60 * However, vnodes within these mounted on file systems have their v_vfsp 61 * fields set to the head filesystem to make NFS happy (see 62 * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t 63 * so that it cannot be freed until all snapshots have been unmounted. 64 */ 65 66#include <sys/zfs_context.h> 67#include <sys/zfs_ctldir.h> 68#include <sys/zfs_ioctl.h> 69#include <sys/zfs_vfsops.h> 70#include <sys/namei.h> 71#include <sys/gfs.h> 72#include <sys/stat.h> 73#include <sys/dmu.h> 74#include <sys/dsl_deleg.h> 75#include <sys/mount.h> 76#include <sys/sunddi.h> 77 78#include "zfs_namecheck.h" 79 80typedef struct zfsctl_node { 81 gfs_dir_t zc_gfs_private; 82 uint64_t zc_id; 83 timestruc_t zc_cmtime; /* ctime and mtime, always the same */ 84} zfsctl_node_t; 85 86typedef struct zfsctl_snapdir { 87 zfsctl_node_t sd_node; 88 kmutex_t sd_lock; 89 avl_tree_t sd_snaps; 90} zfsctl_snapdir_t; 91 92typedef struct { 93 char *se_name; 94 vnode_t *se_root; 95 avl_node_t se_node; 96} zfs_snapentry_t; 97 98static int 99snapentry_compare(const void *a, const void *b) 100{ 101 const zfs_snapentry_t *sa = a; 102 const zfs_snapentry_t *sb = b; 103 int ret = strcmp(sa->se_name, sb->se_name); 104 105 if (ret < 0) 106 return (-1); 107 else if (ret > 0) 108 return (1); 109 else 110 return (0); 111} 112 113#ifdef sun 114vnodeops_t *zfsctl_ops_root; 115vnodeops_t *zfsctl_ops_snapdir; 116vnodeops_t *zfsctl_ops_snapshot; 117vnodeops_t *zfsctl_ops_shares; 118vnodeops_t *zfsctl_ops_shares_dir; 119 120static const fs_operation_def_t zfsctl_tops_root[]; 121static const fs_operation_def_t zfsctl_tops_snapdir[]; 122static const fs_operation_def_t zfsctl_tops_snapshot[]; 123static const fs_operation_def_t zfsctl_tops_shares[]; 124#else /* !sun */ 125static struct vop_vector zfsctl_ops_root; 126static struct vop_vector zfsctl_ops_snapdir; 127static struct vop_vector zfsctl_ops_snapshot; 128static struct vop_vector zfsctl_ops_shares; 129static struct vop_vector zfsctl_ops_shares_dir; 130#endif /* !sun */ 131 132static vnode_t *zfsctl_mknode_snapdir(vnode_t *); 133static vnode_t *zfsctl_mknode_shares(vnode_t *); 134static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset); 135static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *); 136 137#ifdef sun 138static gfs_opsvec_t zfsctl_opsvec[] = { 139 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root }, 140 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir }, 141 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot }, 142 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir }, 143 { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares }, 144 { NULL } 145}; 146#endif /* sun */ 147 148/* 149 * Root directory elements. We only have two entries 150 * snapshot and shares. 151 */ 152static gfs_dirent_t zfsctl_root_entries[] = { 153 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE }, 154 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE }, 155 { NULL } 156}; 157 158/* include . and .. in the calculation */ 159#define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \ 160 sizeof (gfs_dirent_t)) + 1) 161 162 163/* 164 * Initialize the various GFS pieces we'll need to create and manipulate .zfs 165 * directories. This is called from the ZFS init routine, and initializes the 166 * vnode ops vectors that we'll be using. 167 */ 168void 169zfsctl_init(void) 170{ 171#ifdef sun 172 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0); 173#endif 174} 175 176void 177zfsctl_fini(void) 178{ 179#ifdef sun 180 /* 181 * Remove vfsctl vnode ops 182 */ 183 if (zfsctl_ops_root) 184 vn_freevnodeops(zfsctl_ops_root); 185 if (zfsctl_ops_snapdir) 186 vn_freevnodeops(zfsctl_ops_snapdir); 187 if (zfsctl_ops_snapshot) 188 vn_freevnodeops(zfsctl_ops_snapshot); 189 if (zfsctl_ops_shares) 190 vn_freevnodeops(zfsctl_ops_shares); 191 if (zfsctl_ops_shares_dir) 192 vn_freevnodeops(zfsctl_ops_shares_dir); 193 194 zfsctl_ops_root = NULL; 195 zfsctl_ops_snapdir = NULL; 196 zfsctl_ops_snapshot = NULL; 197 zfsctl_ops_shares = NULL; 198 zfsctl_ops_shares_dir = NULL; 199#endif /* sun */ 200} 201 202boolean_t 203zfsctl_is_node(vnode_t *vp) 204{ 205 return (vn_matchops(vp, zfsctl_ops_root) || 206 vn_matchops(vp, zfsctl_ops_snapdir) || 207 vn_matchops(vp, zfsctl_ops_snapshot) || 208 vn_matchops(vp, zfsctl_ops_shares) || 209 vn_matchops(vp, zfsctl_ops_shares_dir)); 210 211} 212 213/* 214 * Return the inode number associated with the 'snapshot' or 215 * 'shares' directory. 216 */ 217/* ARGSUSED */ 218static ino64_t 219zfsctl_root_inode_cb(vnode_t *vp, int index) 220{ 221 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 222 223 ASSERT(index <= 2); 224 225 if (index == 0) 226 return (ZFSCTL_INO_SNAPDIR); 227 228 return (zfsvfs->z_shares_dir); 229} 230 231/* 232 * Create the '.zfs' directory. This directory is cached as part of the VFS 233 * structure. This results in a hold on the vfs_t. The code in zfs_umount() 234 * therefore checks against a vfs_count of 2 instead of 1. This reference 235 * is removed when the ctldir is destroyed in the unmount. 236 */ 237void 238zfsctl_create(zfsvfs_t *zfsvfs) 239{ 240 vnode_t *vp, *rvp; 241 zfsctl_node_t *zcp; 242 uint64_t crtime[2]; 243 244 ASSERT(zfsvfs->z_ctldir == NULL); 245 246 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs, 247 &zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries, 248 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL); 249 zcp = vp->v_data; 250 zcp->zc_id = ZFSCTL_INO_ROOT; 251 252 VERIFY(VFS_ROOT(zfsvfs->z_vfs, LK_EXCLUSIVE, &rvp) == 0); 253 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs), 254 &crtime, sizeof (crtime))); 255 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime); 256 VN_URELE(rvp); 257 258 /* 259 * We're only faking the fact that we have a root of a filesystem for 260 * the sake of the GFS interfaces. Undo the flag manipulation it did 261 * for us. 262 */ 263 vp->v_vflag &= ~VV_ROOT; 264 265 zfsvfs->z_ctldir = vp; 266 267 VOP_UNLOCK(vp, 0); 268} 269 270/* 271 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted. 272 * There might still be more references if we were force unmounted, but only 273 * new zfs_inactive() calls can occur and they don't reference .zfs 274 */ 275void 276zfsctl_destroy(zfsvfs_t *zfsvfs) 277{ 278 VN_RELE(zfsvfs->z_ctldir); 279 zfsvfs->z_ctldir = NULL; 280} 281 282/* 283 * Given a root znode, retrieve the associated .zfs directory. 284 * Add a hold to the vnode and return it. 285 */ 286vnode_t * 287zfsctl_root(znode_t *zp) 288{ 289 ASSERT(zfs_has_ctldir(zp)); 290 VN_HOLD(zp->z_zfsvfs->z_ctldir); 291 return (zp->z_zfsvfs->z_ctldir); 292} 293 294/* 295 * Common open routine. Disallow any write access. 296 */ 297/* ARGSUSED */ 298static int 299zfsctl_common_open(struct vop_open_args *ap) 300{ 301 int flags = ap->a_mode; 302 303 if (flags & FWRITE) 304 return (EACCES); 305 306 return (0); 307} 308 309/* 310 * Common close routine. Nothing to do here. 311 */ 312/* ARGSUSED */ 313static int 314zfsctl_common_close(struct vop_close_args *ap) 315{ 316 return (0); 317} 318 319/* 320 * Common access routine. Disallow writes. 321 */ 322/* ARGSUSED */ 323static int 324zfsctl_common_access(ap) 325 struct vop_access_args /* { 326 struct vnode *a_vp; 327 accmode_t a_accmode; 328 struct ucred *a_cred; 329 struct thread *a_td; 330 } */ *ap; 331{ 332 accmode_t accmode = ap->a_accmode; 333 334#ifdef TODO 335 if (flags & V_ACE_MASK) { 336 if (accmode & ACE_ALL_WRITE_PERMS) 337 return (EACCES); 338 } else { 339#endif 340 if (accmode & VWRITE) 341 return (EACCES); 342#ifdef TODO 343 } 344#endif 345 346 return (0); 347} 348 349/* 350 * Common getattr function. Fill in basic information. 351 */ 352static void 353zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) 354{ 355 timestruc_t now; 356 357 vap->va_uid = 0; 358 vap->va_gid = 0; 359 vap->va_rdev = 0; 360 /* 361 * We are a purely virtual object, so we have no 362 * blocksize or allocated blocks. 363 */ 364 vap->va_blksize = 0; 365 vap->va_nblocks = 0; 366 vap->va_seq = 0; 367 vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0]; 368 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | 369 S_IROTH | S_IXOTH; 370 vap->va_type = VDIR; 371 /* 372 * We live in the now (for atime). 373 */ 374 gethrestime(&now); 375 vap->va_atime = now; 376 /* FreeBSD: Reset chflags(2) flags. */ 377 vap->va_flags = 0; 378} 379 380/*ARGSUSED*/ 381static int 382zfsctl_common_fid(ap) 383 struct vop_fid_args /* { 384 struct vnode *a_vp; 385 struct fid *a_fid; 386 } */ *ap; 387{ 388 vnode_t *vp = ap->a_vp; 389 fid_t *fidp = (void *)ap->a_fid; 390 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 391 zfsctl_node_t *zcp = vp->v_data; 392 uint64_t object = zcp->zc_id; 393 zfid_short_t *zfid; 394 int i; 395 396 ZFS_ENTER(zfsvfs); 397 398 fidp->fid_len = SHORT_FID_LEN; 399 400 zfid = (zfid_short_t *)fidp; 401 402 zfid->zf_len = SHORT_FID_LEN; 403 404 for (i = 0; i < sizeof (zfid->zf_object); i++) 405 zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); 406 407 /* .zfs znodes always have a generation number of 0 */ 408 for (i = 0; i < sizeof (zfid->zf_gen); i++) 409 zfid->zf_gen[i] = 0; 410 411 ZFS_EXIT(zfsvfs); 412 return (0); 413} 414 415 416/*ARGSUSED*/ 417static int 418zfsctl_shares_fid(ap) 419 struct vop_fid_args /* { 420 struct vnode *a_vp; 421 struct fid *a_fid; 422 } */ *ap; 423{ 424 vnode_t *vp = ap->a_vp; 425 fid_t *fidp = (void *)ap->a_fid; 426 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 427 znode_t *dzp; 428 int error; 429 430 ZFS_ENTER(zfsvfs); 431 432 if (zfsvfs->z_shares_dir == 0) { 433 ZFS_EXIT(zfsvfs); 434 return (ENOTSUP); 435 } 436 437 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 438 error = VOP_FID(ZTOV(dzp), fidp); 439 VN_RELE(ZTOV(dzp)); 440 } 441 442 ZFS_EXIT(zfsvfs); 443 return (error); 444} 445 446static int 447zfsctl_common_reclaim(ap) 448 struct vop_reclaim_args /* { 449 struct vnode *a_vp; 450 struct thread *a_td; 451 } */ *ap; 452{ 453 vnode_t *vp = ap->a_vp; 454 455 /* 456 * Destroy the vm object and flush associated pages. 457 */ 458 vnode_destroy_vobject(vp); 459 VI_LOCK(vp); 460 vp->v_data = NULL; 461 VI_UNLOCK(vp); 462 return (0); 463} 464 465/* 466 * .zfs inode namespace 467 * 468 * We need to generate unique inode numbers for all files and directories 469 * within the .zfs pseudo-filesystem. We use the following scheme: 470 * 471 * ENTRY ZFSCTL_INODE 472 * .zfs 1 473 * .zfs/snapshot 2 474 * .zfs/snapshot/<snap> objectid(snap) 475 */ 476 477#define ZFSCTL_INO_SNAP(id) (id) 478 479/* 480 * Get root directory attributes. 481 */ 482/* ARGSUSED */ 483static int 484zfsctl_root_getattr(ap) 485 struct vop_getattr_args /* { 486 struct vnode *a_vp; 487 struct vattr *a_vap; 488 struct ucred *a_cred; 489 } */ *ap; 490{ 491 struct vnode *vp = ap->a_vp; 492 struct vattr *vap = ap->a_vap; 493 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 494 zfsctl_node_t *zcp = vp->v_data; 495 496 ZFS_ENTER(zfsvfs); 497 vap->va_nodeid = ZFSCTL_INO_ROOT; 498 vap->va_nlink = vap->va_size = NROOT_ENTRIES; 499 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; 500 vap->va_birthtime = vap->va_ctime; 501 502 zfsctl_common_getattr(vp, vap); 503 ZFS_EXIT(zfsvfs); 504 505 return (0); 506} 507 508/* 509 * Special case the handling of "..". 510 */ 511/* ARGSUSED */ 512int 513zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 514 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 515 int *direntflags, pathname_t *realpnp) 516{ 517 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 518 int err; 519 520 /* 521 * No extended attributes allowed under .zfs 522 */ 523 if (flags & LOOKUP_XATTR) 524 return (EINVAL); 525 526 ZFS_ENTER(zfsvfs); 527 528 if (strcmp(nm, "..") == 0) { 529 err = VFS_ROOT(dvp->v_vfsp, LK_EXCLUSIVE, vpp); 530 if (err == 0) 531 VOP_UNLOCK(*vpp, 0); 532 } else { 533 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, 534 cr, ct, direntflags, realpnp); 535 } 536 537 ZFS_EXIT(zfsvfs); 538 539 return (err); 540} 541 542#ifdef sun 543static int 544zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, 545 caller_context_t *ct) 546{ 547 /* 548 * We only care about ACL_ENABLED so that libsec can 549 * display ACL correctly and not default to POSIX draft. 550 */ 551 if (cmd == _PC_ACL_ENABLED) { 552 *valp = _ACL_ACE_ENABLED; 553 return (0); 554 } 555 556 return (fs_pathconf(vp, cmd, valp, cr, ct)); 557} 558#endif /* sun */ 559 560#ifdef sun 561static const fs_operation_def_t zfsctl_tops_root[] = { 562 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 563 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 564 { VOPNAME_IOCTL, { .error = fs_inval } }, 565 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, 566 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 567 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 568 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, 569 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 570 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 571 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } }, 572 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 573 { NULL } 574}; 575#endif /* sun */ 576 577/* 578 * Special case the handling of "..". 579 */ 580/* ARGSUSED */ 581int 582zfsctl_freebsd_root_lookup(ap) 583 struct vop_lookup_args /* { 584 struct vnode *a_dvp; 585 struct vnode **a_vpp; 586 struct componentname *a_cnp; 587 } */ *ap; 588{ 589 vnode_t *dvp = ap->a_dvp; 590 vnode_t **vpp = ap->a_vpp; 591 cred_t *cr = ap->a_cnp->cn_cred; 592 int flags = ap->a_cnp->cn_flags; 593 int nameiop = ap->a_cnp->cn_nameiop; 594 char nm[NAME_MAX + 1]; 595 int err; 596 597 if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE)) 598 return (EOPNOTSUPP); 599 600 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 601 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 602 603 err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL); 604 if (err == 0 && (nm[0] != '.' || nm[1] != '\0')) 605 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 606 return (err); 607} 608 609static struct vop_vector zfsctl_ops_root = { 610 .vop_default = &default_vnodeops, 611 .vop_open = zfsctl_common_open, 612 .vop_close = zfsctl_common_close, 613 .vop_ioctl = VOP_EINVAL, 614 .vop_getattr = zfsctl_root_getattr, 615 .vop_access = zfsctl_common_access, 616 .vop_readdir = gfs_vop_readdir, 617 .vop_lookup = zfsctl_freebsd_root_lookup, 618 .vop_inactive = gfs_vop_inactive, 619 .vop_reclaim = zfsctl_common_reclaim, 620#ifdef TODO 621 .vop_pathconf = zfsctl_pathconf, 622#endif 623 .vop_fid = zfsctl_common_fid, 624}; 625 626static int 627zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) 628{ 629 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; 630 631 if (snapshot_namecheck(name, NULL, NULL) != 0) 632 return (EILSEQ); 633 dmu_objset_name(os, zname); 634 if (strlen(zname) + 1 + strlen(name) >= len) 635 return (ENAMETOOLONG); 636 (void) strcat(zname, "@"); 637 (void) strcat(zname, name); 638 return (0); 639} 640 641static int 642zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) 643{ 644 vnode_t *svp = sep->se_root; 645 int error; 646 647 ASSERT(vn_ismntpt(svp)); 648 649 /* this will be dropped by dounmount() */ 650 if ((error = vn_vfswlock(svp)) != 0) 651 return (error); 652 653#ifdef sun 654 VN_HOLD(svp); 655 error = dounmount(vn_mountedvfs(svp), fflags, cr); 656 if (error) { 657 VN_RELE(svp); 658 return (error); 659 } 660 661 /* 662 * We can't use VN_RELE(), as that will try to invoke 663 * zfsctl_snapdir_inactive(), which would cause us to destroy 664 * the sd_lock mutex held by our caller. 665 */ 666 ASSERT(svp->v_count == 1); 667 gfs_vop_inactive(svp, cr, NULL); 668 669 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 670 kmem_free(sep, sizeof (zfs_snapentry_t)); 671 672 return (0); 673#else /* !sun */ 674 return (dounmount(vn_mountedvfs(svp), fflags, curthread)); 675#endif /* !sun */ 676} 677 678#ifdef sun 679static void 680zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) 681{ 682 avl_index_t where; 683 vfs_t *vfsp; 684 refstr_t *pathref; 685 char newpath[MAXNAMELEN]; 686 char *tail; 687 688 ASSERT(MUTEX_HELD(&sdp->sd_lock)); 689 ASSERT(sep != NULL); 690 691 vfsp = vn_mountedvfs(sep->se_root); 692 ASSERT(vfsp != NULL); 693 694 vfs_lock_wait(vfsp); 695 696 /* 697 * Change the name in the AVL tree. 698 */ 699 avl_remove(&sdp->sd_snaps, sep); 700 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 701 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 702 (void) strcpy(sep->se_name, nm); 703 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); 704 avl_insert(&sdp->sd_snaps, sep, where); 705 706 /* 707 * Change the current mountpoint info: 708 * - update the tail of the mntpoint path 709 * - update the tail of the resource path 710 */ 711 pathref = vfs_getmntpoint(vfsp); 712 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 713 VERIFY((tail = strrchr(newpath, '/')) != NULL); 714 *(tail+1) = '\0'; 715 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 716 (void) strcat(newpath, nm); 717 refstr_rele(pathref); 718 vfs_setmntpoint(vfsp, newpath, 0); 719 720 pathref = vfs_getresource(vfsp); 721 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 722 VERIFY((tail = strrchr(newpath, '@')) != NULL); 723 *(tail+1) = '\0'; 724 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 725 (void) strcat(newpath, nm); 726 refstr_rele(pathref); 727 vfs_setresource(vfsp, newpath, 0); 728 729 vfs_unlock(vfsp); 730} 731#endif /* sun */ 732 733#ifdef sun 734/*ARGSUSED*/ 735static int 736zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, 737 cred_t *cr, caller_context_t *ct, int flags) 738{ 739 zfsctl_snapdir_t *sdp = sdvp->v_data; 740 zfs_snapentry_t search, *sep; 741 zfsvfs_t *zfsvfs; 742 avl_index_t where; 743 char from[MAXNAMELEN], to[MAXNAMELEN]; 744 char real[MAXNAMELEN]; 745 int err; 746 747 zfsvfs = sdvp->v_vfsp->vfs_data; 748 ZFS_ENTER(zfsvfs); 749 750 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 751 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, 752 MAXNAMELEN, NULL); 753 if (err == 0) { 754 snm = real; 755 } else if (err != ENOTSUP) { 756 ZFS_EXIT(zfsvfs); 757 return (err); 758 } 759 } 760 761 ZFS_EXIT(zfsvfs); 762 763 err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from); 764 if (!err) 765 err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to); 766 if (!err) 767 err = zfs_secpolicy_rename_perms(from, to, cr); 768 if (err) 769 return (err); 770 771 /* 772 * Cannot move snapshots out of the snapdir. 773 */ 774 if (sdvp != tdvp) 775 return (EINVAL); 776 777 if (strcmp(snm, tnm) == 0) 778 return (0); 779 780 mutex_enter(&sdp->sd_lock); 781 782 search.se_name = (char *)snm; 783 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { 784 mutex_exit(&sdp->sd_lock); 785 return (ENOENT); 786 } 787 788 err = dmu_objset_rename(from, to, B_FALSE); 789 if (err == 0) 790 zfsctl_rename_snap(sdp, sep, tnm); 791 792 mutex_exit(&sdp->sd_lock); 793 794 return (err); 795} 796#endif /* sun */ 797 798#ifdef sun 799/* ARGSUSED */ 800static int 801zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, 802 caller_context_t *ct, int flags) 803{ 804 zfsctl_snapdir_t *sdp = dvp->v_data; 805 zfs_snapentry_t *sep; 806 zfs_snapentry_t search; 807 zfsvfs_t *zfsvfs; 808 char snapname[MAXNAMELEN]; 809 char real[MAXNAMELEN]; 810 int err; 811 812 zfsvfs = dvp->v_vfsp->vfs_data; 813 ZFS_ENTER(zfsvfs); 814 815 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 816 817 err = dmu_snapshot_realname(zfsvfs->z_os, name, real, 818 MAXNAMELEN, NULL); 819 if (err == 0) { 820 name = real; 821 } else if (err != ENOTSUP) { 822 ZFS_EXIT(zfsvfs); 823 return (err); 824 } 825 } 826 827 ZFS_EXIT(zfsvfs); 828 829 err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname); 830 if (!err) 831 err = zfs_secpolicy_destroy_perms(snapname, cr); 832 if (err) 833 return (err); 834 835 mutex_enter(&sdp->sd_lock); 836 837 search.se_name = name; 838 sep = avl_find(&sdp->sd_snaps, &search, NULL); 839 if (sep) { 840 avl_remove(&sdp->sd_snaps, sep); 841 err = zfsctl_unmount_snap(sep, MS_FORCE, cr); 842 if (err) { 843 avl_index_t where; 844 845 if (avl_find(&sdp->sd_snaps, sep, &where) == NULL) 846 avl_insert(&sdp->sd_snaps, sep, where); 847 } else 848 err = dmu_objset_destroy(snapname, B_FALSE); 849 } else { 850 err = ENOENT; 851 } 852 853 mutex_exit(&sdp->sd_lock); 854 855 return (err); 856} 857#endif /* sun */ 858 859/* 860 * This creates a snapshot under '.zfs/snapshot'. 861 */ 862/* ARGSUSED */ 863static int 864zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, 865 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) 866{ 867 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 868 char name[MAXNAMELEN]; 869 int err; 870 static enum symfollow follow = NO_FOLLOW; 871 static enum uio_seg seg = UIO_SYSSPACE; 872 873 if (snapshot_namecheck(dirname, NULL, NULL) != 0) 874 return (EILSEQ); 875 876 dmu_objset_name(zfsvfs->z_os, name); 877 878 *vpp = NULL; 879 880 err = zfs_secpolicy_snapshot_perms(name, cr); 881 if (err) 882 return (err); 883 884 if (err == 0) { 885 err = dmu_objset_snapshot(name, dirname, NULL, NULL, 886 B_FALSE, B_FALSE, -1); 887 if (err) 888 return (err); 889 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); 890 } 891 892 return (err); 893} 894 895static int 896zfsctl_freebsd_snapdir_mkdir(ap) 897 struct vop_mkdir_args /* { 898 struct vnode *a_dvp; 899 struct vnode **a_vpp; 900 struct componentname *a_cnp; 901 struct vattr *a_vap; 902 } */ *ap; 903{ 904 905 ASSERT(ap->a_cnp->cn_flags & SAVENAME); 906 907 return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL, 908 ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL)); 909} 910 911/* 912 * Lookup entry point for the 'snapshot' directory. Try to open the 913 * snapshot if it exist, creating the pseudo filesystem vnode as necessary. 914 * Perform a mount of the associated dataset on top of the vnode. 915 */ 916/* ARGSUSED */ 917int 918zfsctl_snapdir_lookup(ap) 919 struct vop_lookup_args /* { 920 struct vnode *a_dvp; 921 struct vnode **a_vpp; 922 struct componentname *a_cnp; 923 } */ *ap; 924{ 925 vnode_t *dvp = ap->a_dvp; 926 vnode_t **vpp = ap->a_vpp; 927 struct componentname *cnp = ap->a_cnp; 928 char nm[NAME_MAX + 1]; 929 zfsctl_snapdir_t *sdp = dvp->v_data; 930 objset_t *snap; 931 char snapname[MAXNAMELEN]; 932 char real[MAXNAMELEN]; 933 char *mountpoint; 934 zfs_snapentry_t *sep, search; 935 size_t mountpoint_len; 936 avl_index_t where; 937 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 938 int err; 939 int flags = 0; 940 941 /* 942 * No extended attributes allowed under .zfs 943 */ 944 if (flags & LOOKUP_XATTR) 945 return (EINVAL); 946 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); 947 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); 948 949 ASSERT(dvp->v_type == VDIR); 950 951 *vpp = NULL; 952 953 /* 954 * If we get a recursive call, that means we got called 955 * from the domount() code while it was trying to look up the 956 * spec (which looks like a local path for zfs). We need to 957 * add some flag to domount() to tell it not to do this lookup. 958 */ 959 if (MUTEX_HELD(&sdp->sd_lock)) 960 return (ENOENT); 961 962 ZFS_ENTER(zfsvfs); 963 964 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 965 ZFS_EXIT(zfsvfs); 966 return (0); 967 } 968 969 if (flags & FIGNORECASE) { 970 boolean_t conflict = B_FALSE; 971 972 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, 973 MAXNAMELEN, &conflict); 974 if (err == 0) { 975 strlcpy(nm, real, sizeof(nm)); 976 } else if (err != ENOTSUP) { 977 ZFS_EXIT(zfsvfs); 978 return (err); 979 } 980#if 0 981 if (realpnp) 982 (void) strlcpy(realpnp->pn_buf, nm, 983 realpnp->pn_bufsize); 984 if (conflict && direntflags) 985 *direntflags = ED_CASE_CONFLICT; 986#endif 987 } 988 989 mutex_enter(&sdp->sd_lock); 990 search.se_name = (char *)nm; 991 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { 992 *vpp = sep->se_root; 993 VN_HOLD(*vpp); 994 err = traverse(vpp, LK_EXCLUSIVE | LK_RETRY); 995 if (err) { 996 VN_RELE(*vpp); 997 *vpp = NULL; 998 } else if (*vpp == sep->se_root) { 999 /* 1000 * The snapshot was unmounted behind our backs, 1001 * try to remount it. 1002 */ 1003 goto domount; 1004 } else { 1005 /* 1006 * VROOT was set during the traverse call. We need 1007 * to clear it since we're pretending to be part 1008 * of our parent's vfs. 1009 */ 1010 (*vpp)->v_flag &= ~VROOT; 1011 } 1012 mutex_exit(&sdp->sd_lock); 1013 ZFS_EXIT(zfsvfs); 1014 return (err); 1015 } 1016 1017 /* 1018 * The requested snapshot is not currently mounted, look it up. 1019 */ 1020 err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname); 1021 if (err) { 1022 mutex_exit(&sdp->sd_lock); 1023 ZFS_EXIT(zfsvfs); 1024 /* 1025 * handle "ls *" or "?" in a graceful manner, 1026 * forcing EILSEQ to ENOENT. 1027 * Since shell ultimately passes "*" or "?" as name to lookup 1028 */ 1029 return (err == EILSEQ ? ENOENT : err); 1030 } 1031 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) { 1032 mutex_exit(&sdp->sd_lock); 1033 /* Translate errors and add SAVENAME when needed. */ 1034 if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) { 1035 err = EJUSTRETURN; 1036 cnp->cn_flags |= SAVENAME; 1037 } else { 1038 err = ENOENT; 1039 } 1040 ZFS_EXIT(zfsvfs); 1041 return (err); 1042 } 1043 1044 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); 1045 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 1046 (void) strcpy(sep->se_name, nm); 1047 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); 1048 VN_HOLD(*vpp); 1049 avl_insert(&sdp->sd_snaps, sep, where); 1050 1051 dmu_objset_rele(snap, FTAG); 1052domount: 1053 mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) + 1054 strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1; 1055 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); 1056 (void) snprintf(mountpoint, mountpoint_len, 1057 "%s/" ZFS_CTLDIR_NAME "/snapshot/%s", 1058 dvp->v_vfsp->mnt_stat.f_mntonname, nm); 1059 err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0); 1060 kmem_free(mountpoint, mountpoint_len); 1061 if (err == 0) { 1062 /* 1063 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>. 1064 * 1065 * This is where we lie about our v_vfsp in order to 1066 * make .zfs/snapshot/<snapname> accessible over NFS 1067 * without requiring manual mounts of <snapname>. 1068 */ 1069 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); 1070 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; 1071 } 1072 mutex_exit(&sdp->sd_lock); 1073 ZFS_EXIT(zfsvfs); 1074 if (err != 0) 1075 *vpp = NULL; 1076 return (err); 1077} 1078 1079/* ARGSUSED */ 1080int 1081zfsctl_shares_lookup(ap) 1082 struct vop_lookup_args /* { 1083 struct vnode *a_dvp; 1084 struct vnode **a_vpp; 1085 struct componentname *a_cnp; 1086 } */ *ap; 1087{ 1088 vnode_t *dvp = ap->a_dvp; 1089 vnode_t **vpp = ap->a_vpp; 1090 struct componentname *cnp = ap->a_cnp; 1091 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1092 char nm[NAME_MAX + 1]; 1093 znode_t *dzp; 1094 int error; 1095 1096 ZFS_ENTER(zfsvfs); 1097 1098 ASSERT(cnp->cn_namelen < sizeof(nm)); 1099 strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1); 1100 1101 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 1102 ZFS_EXIT(zfsvfs); 1103 return (0); 1104 } 1105 1106 if (zfsvfs->z_shares_dir == 0) { 1107 ZFS_EXIT(zfsvfs); 1108 return (ENOTSUP); 1109 } 1110 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) 1111 error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp); 1112 1113 VN_RELE(ZTOV(dzp)); 1114 ZFS_EXIT(zfsvfs); 1115 1116 return (error); 1117} 1118 1119/* ARGSUSED */ 1120static int 1121zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, 1122 offset_t *offp, offset_t *nextp, void *data, int flags) 1123{ 1124 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1125 char snapname[MAXNAMELEN]; 1126 uint64_t id, cookie; 1127 boolean_t case_conflict; 1128 int error; 1129 1130 ZFS_ENTER(zfsvfs); 1131 1132 cookie = *offp; 1133 error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id, 1134 &cookie, &case_conflict); 1135 if (error) { 1136 ZFS_EXIT(zfsvfs); 1137 if (error == ENOENT) { 1138 *eofp = 1; 1139 return (0); 1140 } 1141 return (error); 1142 } 1143 1144 if (flags & V_RDDIR_ENTFLAGS) { 1145 edirent_t *eodp = dp; 1146 1147 (void) strcpy(eodp->ed_name, snapname); 1148 eodp->ed_ino = ZFSCTL_INO_SNAP(id); 1149 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; 1150 } else { 1151 struct dirent64 *odp = dp; 1152 1153 (void) strcpy(odp->d_name, snapname); 1154 odp->d_ino = ZFSCTL_INO_SNAP(id); 1155 } 1156 *nextp = cookie; 1157 1158 ZFS_EXIT(zfsvfs); 1159 1160 return (0); 1161} 1162 1163/* ARGSUSED */ 1164static int 1165zfsctl_shares_readdir(ap) 1166 struct vop_readdir_args /* { 1167 struct vnode *a_vp; 1168 struct uio *a_uio; 1169 struct ucred *a_cred; 1170 int *a_eofflag; 1171 int *a_ncookies; 1172 u_long **a_cookies; 1173 } */ *ap; 1174{ 1175 vnode_t *vp = ap->a_vp; 1176 uio_t *uiop = ap->a_uio; 1177 cred_t *cr = ap->a_cred; 1178 int *eofp = ap->a_eofflag; 1179 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1180 znode_t *dzp; 1181 int error; 1182 1183 ZFS_ENTER(zfsvfs); 1184 1185 if (zfsvfs->z_shares_dir == 0) { 1186 ZFS_EXIT(zfsvfs); 1187 return (ENOTSUP); 1188 } 1189 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1190 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1191 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies); 1192 VN_URELE(ZTOV(dzp)); 1193 } else { 1194 *eofp = 1; 1195 error = ENOENT; 1196 } 1197 1198 ZFS_EXIT(zfsvfs); 1199 return (error); 1200} 1201 1202/* 1203 * pvp is the '.zfs' directory (zfsctl_node_t). 1204 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). 1205 * 1206 * This function is the callback to create a GFS vnode for '.zfs/snapshot' 1207 * when a lookup is performed on .zfs for "snapshot". 1208 */ 1209vnode_t * 1210zfsctl_mknode_snapdir(vnode_t *pvp) 1211{ 1212 vnode_t *vp; 1213 zfsctl_snapdir_t *sdp; 1214 1215 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, pvp->v_vfsp, 1216 &zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, 1217 zfsctl_snapdir_readdir_cb, NULL); 1218 sdp = vp->v_data; 1219 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; 1220 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1221 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 1222 avl_create(&sdp->sd_snaps, snapentry_compare, 1223 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); 1224 VOP_UNLOCK(vp, 0); 1225 return (vp); 1226} 1227 1228vnode_t * 1229zfsctl_mknode_shares(vnode_t *pvp) 1230{ 1231 vnode_t *vp; 1232 zfsctl_node_t *sdp; 1233 1234 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1235 &zfsctl_ops_shares, NULL, NULL, MAXNAMELEN, 1236 NULL, NULL); 1237 sdp = vp->v_data; 1238 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1239 VOP_UNLOCK(vp, 0); 1240 return (vp); 1241 1242} 1243 1244/* ARGSUSED */ 1245static int 1246zfsctl_shares_getattr(ap) 1247 struct vop_getattr_args /* { 1248 struct vnode *a_vp; 1249 struct vattr *a_vap; 1250 struct ucred *a_cred; 1251 struct thread *a_td; 1252 } */ *ap; 1253{ 1254 vnode_t *vp = ap->a_vp; 1255 vattr_t *vap = ap->a_vap; 1256 cred_t *cr = ap->a_cred; 1257 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1258 znode_t *dzp; 1259 int error; 1260 1261 ZFS_ENTER(zfsvfs); 1262 if (zfsvfs->z_shares_dir == 0) { 1263 ZFS_EXIT(zfsvfs); 1264 return (ENOTSUP); 1265 } 1266 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1267 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); 1268 error = VOP_GETATTR(ZTOV(dzp), vap, cr); 1269 VN_URELE(ZTOV(dzp)); 1270 } 1271 ZFS_EXIT(zfsvfs); 1272 return (error); 1273 1274 1275} 1276 1277/* ARGSUSED */ 1278static int 1279zfsctl_snapdir_getattr(ap) 1280 struct vop_getattr_args /* { 1281 struct vnode *a_vp; 1282 struct vattr *a_vap; 1283 struct ucred *a_cred; 1284 } */ *ap; 1285{ 1286 vnode_t *vp = ap->a_vp; 1287 vattr_t *vap = ap->a_vap; 1288 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1289 zfsctl_snapdir_t *sdp = vp->v_data; 1290 1291 ZFS_ENTER(zfsvfs); 1292 zfsctl_common_getattr(vp, vap); 1293 vap->va_nodeid = gfs_file_inode(vp); 1294 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; 1295 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); 1296 vap->va_birthtime = vap->va_ctime; 1297 ZFS_EXIT(zfsvfs); 1298 1299 return (0); 1300} 1301 1302/* ARGSUSED */ 1303static int 1304zfsctl_snapdir_inactive(ap) 1305 struct vop_inactive_args /* { 1306 struct vnode *a_vp; 1307 struct thread *a_td; 1308 } */ *ap; 1309{ 1310 vnode_t *vp = ap->a_vp; 1311 zfsctl_snapdir_t *sdp = vp->v_data; 1312 zfs_snapentry_t *sep; 1313 1314 /* 1315 * On forced unmount we have to free snapshots from here. 1316 */ 1317 mutex_enter(&sdp->sd_lock); 1318 while ((sep = avl_first(&sdp->sd_snaps)) != NULL) { 1319 avl_remove(&sdp->sd_snaps, sep); 1320 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1321 kmem_free(sep, sizeof (zfs_snapentry_t)); 1322 } 1323 mutex_exit(&sdp->sd_lock); 1324 gfs_dir_inactive(vp); 1325 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); 1326 mutex_destroy(&sdp->sd_lock); 1327 avl_destroy(&sdp->sd_snaps); 1328 kmem_free(sdp, sizeof (zfsctl_snapdir_t)); 1329 1330 return (0); 1331} 1332 1333#ifdef sun 1334static const fs_operation_def_t zfsctl_tops_snapdir[] = { 1335 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1336 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1337 { VOPNAME_IOCTL, { .error = fs_inval } }, 1338 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, 1339 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1340 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, 1341 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, 1342 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, 1343 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 1344 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, 1345 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1346 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, 1347 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 1348 { NULL } 1349}; 1350 1351static const fs_operation_def_t zfsctl_tops_shares[] = { 1352 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1353 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1354 { VOPNAME_IOCTL, { .error = fs_inval } }, 1355 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } }, 1356 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1357 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } }, 1358 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } }, 1359 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1360 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 1361 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } }, 1362 { NULL } 1363}; 1364#else /* !sun */ 1365static struct vop_vector zfsctl_ops_snapdir = { 1366 .vop_default = &default_vnodeops, 1367 .vop_open = zfsctl_common_open, 1368 .vop_close = zfsctl_common_close, 1369 .vop_ioctl = VOP_EINVAL, 1370 .vop_getattr = zfsctl_snapdir_getattr, 1371 .vop_access = zfsctl_common_access, 1372 .vop_mkdir = zfsctl_freebsd_snapdir_mkdir, 1373 .vop_readdir = gfs_vop_readdir, 1374 .vop_lookup = zfsctl_snapdir_lookup, 1375 .vop_inactive = zfsctl_snapdir_inactive, 1376 .vop_reclaim = zfsctl_common_reclaim, 1377 .vop_fid = zfsctl_common_fid, 1378}; 1379 1380static struct vop_vector zfsctl_ops_shares = { 1381 .vop_default = &default_vnodeops, 1382 .vop_open = zfsctl_common_open, 1383 .vop_close = zfsctl_common_close, 1384 .vop_ioctl = VOP_EINVAL, 1385 .vop_getattr = zfsctl_shares_getattr, 1386 .vop_access = zfsctl_common_access, 1387 .vop_readdir = zfsctl_shares_readdir, 1388 .vop_lookup = zfsctl_shares_lookup, 1389 .vop_inactive = gfs_vop_inactive, 1390 .vop_reclaim = zfsctl_common_reclaim, 1391 .vop_fid = zfsctl_shares_fid, 1392}; 1393#endif /* !sun */ 1394 1395/* 1396 * pvp is the GFS vnode '.zfs/snapshot'. 1397 * 1398 * This creates a GFS node under '.zfs/snapshot' representing each 1399 * snapshot. This newly created GFS node is what we mount snapshot 1400 * vfs_t's ontop of. 1401 */ 1402static vnode_t * 1403zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) 1404{ 1405 vnode_t *vp; 1406 zfsctl_node_t *zcp; 1407 1408 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, 1409 &zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); 1410 VN_HOLD(vp); 1411 zcp = vp->v_data; 1412 zcp->zc_id = objset; 1413 VOP_UNLOCK(vp, 0); 1414 1415 return (vp); 1416} 1417 1418static int 1419zfsctl_snapshot_inactive(ap) 1420 struct vop_inactive_args /* { 1421 struct vnode *a_vp; 1422 struct thread *a_td; 1423 } */ *ap; 1424{ 1425 vnode_t *vp = ap->a_vp; 1426 cred_t *cr = ap->a_td->td_ucred; 1427 struct vop_inactive_args iap; 1428 zfsctl_snapdir_t *sdp; 1429 zfs_snapentry_t *sep, *next; 1430 int locked; 1431 vnode_t *dvp; 1432 1433 if (vp->v_count > 0) 1434 goto end; 1435 1436 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); 1437 sdp = dvp->v_data; 1438 VOP_UNLOCK(dvp, 0); 1439 1440 if (!(locked = MUTEX_HELD(&sdp->sd_lock))) 1441 mutex_enter(&sdp->sd_lock); 1442 1443 ASSERT(!vn_ismntpt(vp)); 1444 1445 sep = avl_first(&sdp->sd_snaps); 1446 while (sep != NULL) { 1447 next = AVL_NEXT(&sdp->sd_snaps, sep); 1448 1449 if (sep->se_root == vp) { 1450 avl_remove(&sdp->sd_snaps, sep); 1451 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1452 kmem_free(sep, sizeof (zfs_snapentry_t)); 1453 break; 1454 } 1455 sep = next; 1456 } 1457 ASSERT(sep != NULL); 1458 1459 if (!locked) 1460 mutex_exit(&sdp->sd_lock); 1461 VN_RELE(dvp); 1462 1463end: 1464 /* 1465 * Dispose of the vnode for the snapshot mount point. 1466 * This is safe to do because once this entry has been removed 1467 * from the AVL tree, it can't be found again, so cannot become 1468 * "active". If we lookup the same name again we will end up 1469 * creating a new vnode. 1470 */ 1471 iap.a_vp = vp; 1472 return (gfs_vop_inactive(&iap)); 1473} 1474 1475static int 1476zfsctl_traverse_begin(vnode_t **vpp, int lktype) 1477{ 1478 1479 VN_HOLD(*vpp); 1480 /* Snapshot should be already mounted, but just in case. */ 1481 if (vn_mountedvfs(*vpp) == NULL) 1482 return (ENOENT); 1483 return (traverse(vpp, lktype)); 1484} 1485 1486static void 1487zfsctl_traverse_end(vnode_t *vp, int err) 1488{ 1489 1490 if (err == 0) 1491 vput(vp); 1492 else 1493 VN_RELE(vp); 1494} 1495 1496static int 1497zfsctl_snapshot_getattr(ap) 1498 struct vop_getattr_args /* { 1499 struct vnode *a_vp; 1500 struct vattr *a_vap; 1501 struct ucred *a_cred; 1502 } */ *ap; 1503{ 1504 vnode_t *vp = ap->a_vp; 1505 int err; 1506 1507 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1508 if (err == 0) 1509 err = VOP_GETATTR(vp, ap->a_vap, ap->a_cred); 1510 zfsctl_traverse_end(vp, err); 1511 return (err); 1512} 1513 1514static int 1515zfsctl_snapshot_fid(ap) 1516 struct vop_fid_args /* { 1517 struct vnode *a_vp; 1518 struct fid *a_fid; 1519 } */ *ap; 1520{ 1521 vnode_t *vp = ap->a_vp; 1522 int err; 1523 1524 err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY); 1525 if (err == 0) 1526 err = VOP_VPTOFH(vp, (void *)ap->a_fid); 1527 zfsctl_traverse_end(vp, err); 1528 return (err); 1529} 1530 1531static int 1532zfsctl_snapshot_lookup(ap) 1533 struct vop_lookup_args /* { 1534 struct vnode *a_dvp; 1535 struct vnode **a_vpp; 1536 struct componentname *a_cnp; 1537 } */ *ap; 1538{ 1539 vnode_t *dvp = ap->a_dvp; 1540 vnode_t **vpp = ap->a_vpp; 1541 struct componentname *cnp = ap->a_cnp; 1542 cred_t *cr = ap->a_cnp->cn_cred; 1543 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 1544 int error; 1545 1546 if (cnp->cn_namelen != 2 || cnp->cn_nameptr[0] != '.' || 1547 cnp->cn_nameptr[1] != '.') { 1548 return (ENOENT); 1549 } 1550 1551 ASSERT(dvp->v_type == VDIR); 1552 ASSERT(zfsvfs->z_ctldir != NULL); 1553 1554 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", vpp, 1555 NULL, 0, NULL, cr, NULL, NULL, NULL); 1556 if (error == 0) 1557 vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY); 1558 return (error); 1559} 1560 1561static int 1562zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap) 1563{ 1564 zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data; 1565 vnode_t *dvp, *vp; 1566 zfsctl_snapdir_t *sdp; 1567 zfs_snapentry_t *sep; 1568 int error; 1569 1570 ASSERT(zfsvfs->z_ctldir != NULL); 1571 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1572 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1573 if (error != 0) 1574 return (error); 1575 sdp = dvp->v_data; 1576 1577 mutex_enter(&sdp->sd_lock); 1578 sep = avl_first(&sdp->sd_snaps); 1579 while (sep != NULL) { 1580 vp = sep->se_root; 1581 if (vp == ap->a_vp) 1582 break; 1583 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1584 } 1585 if (sep == NULL) { 1586 mutex_exit(&sdp->sd_lock); 1587 error = ENOENT; 1588 } else { 1589 size_t len; 1590 1591 len = strlen(sep->se_name); 1592 *ap->a_buflen -= len; 1593 bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len); 1594 mutex_exit(&sdp->sd_lock); 1595 vhold(dvp); 1596 *ap->a_vpp = dvp; 1597 } 1598 VN_RELE(dvp); 1599 1600 return (error); 1601} 1602 1603/* 1604 * These VP's should never see the light of day. They should always 1605 * be covered. 1606 */ 1607static struct vop_vector zfsctl_ops_snapshot = { 1608 .vop_default = &default_vnodeops, 1609 .vop_inactive = zfsctl_snapshot_inactive, 1610 .vop_lookup = zfsctl_snapshot_lookup, 1611 .vop_reclaim = zfsctl_common_reclaim, 1612 .vop_getattr = zfsctl_snapshot_getattr, 1613 .vop_fid = zfsctl_snapshot_fid, 1614 .vop_vptocnp = zfsctl_snapshot_vptocnp, 1615}; 1616 1617int 1618zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) 1619{ 1620 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1621 vnode_t *dvp, *vp; 1622 zfsctl_snapdir_t *sdp; 1623 zfsctl_node_t *zcp; 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 zcp = vp->v_data; 1639 if (zcp->zc_id == objsetid) 1640 break; 1641 1642 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1643 } 1644 1645 if (sep != NULL) { 1646 VN_HOLD(vp); 1647 /* 1648 * Return the mounted root rather than the covered mount point. 1649 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> 1650 * and returns the ZFS vnode mounted on top of the GFS node. 1651 * This ZFS vnode is the root of the vfs for objset 'objsetid'. 1652 */ 1653 error = traverse(&vp, LK_SHARED | LK_RETRY); 1654 if (error == 0) { 1655 if (vp == sep->se_root) 1656 error = EINVAL; 1657 else 1658 *zfsvfsp = VTOZ(vp)->z_zfsvfs; 1659 } 1660 mutex_exit(&sdp->sd_lock); 1661 if (error == 0) 1662 VN_URELE(vp); 1663 else 1664 VN_RELE(vp); 1665 } else { 1666 error = EINVAL; 1667 mutex_exit(&sdp->sd_lock); 1668 } 1669 1670 VN_RELE(dvp); 1671 1672 return (error); 1673} 1674 1675/* 1676 * Unmount any snapshots for the given filesystem. This is called from 1677 * zfs_umount() - if we have a ctldir, then go through and unmount all the 1678 * snapshots. 1679 */ 1680int 1681zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) 1682{ 1683 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1684 vnode_t *dvp; 1685 zfsctl_snapdir_t *sdp; 1686 zfs_snapentry_t *sep, *next; 1687 int error; 1688 1689 ASSERT(zfsvfs->z_ctldir != NULL); 1690 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1691 NULL, 0, NULL, cr, NULL, NULL, NULL); 1692 if (error != 0) 1693 return (error); 1694 sdp = dvp->v_data; 1695 1696 mutex_enter(&sdp->sd_lock); 1697 1698 sep = avl_first(&sdp->sd_snaps); 1699 while (sep != NULL) { 1700 next = AVL_NEXT(&sdp->sd_snaps, sep); 1701 1702 /* 1703 * If this snapshot is not mounted, then it must 1704 * have just been unmounted by somebody else, and 1705 * will be cleaned up by zfsctl_snapdir_inactive(). 1706 */ 1707 if (vn_ismntpt(sep->se_root)) { 1708 error = zfsctl_unmount_snap(sep, fflags, cr); 1709 if (error) { 1710 avl_index_t where; 1711 1712 /* 1713 * Before reinserting snapshot to the tree, 1714 * check if it was actually removed. For example 1715 * when snapshot mount point is busy, we will 1716 * have an error here, but there will be no need 1717 * to reinsert snapshot. 1718 */ 1719 if (avl_find(&sdp->sd_snaps, sep, &where) == NULL) 1720 avl_insert(&sdp->sd_snaps, sep, where); 1721 break; 1722 } 1723 } 1724 sep = next; 1725 } 1726 1727 mutex_exit(&sdp->sd_lock); 1728 VN_RELE(dvp); 1729 1730 return (error); 1731} 1732