diff options
Diffstat (limited to 'zfs/lib/libdmu-ctl/zfs_ctldir.c')
| -rw-r--r-- | zfs/lib/libdmu-ctl/zfs_ctldir.c | 1147 |
1 files changed, 0 insertions, 1147 deletions
diff --git a/zfs/lib/libdmu-ctl/zfs_ctldir.c b/zfs/lib/libdmu-ctl/zfs_ctldir.c deleted file mode 100644 index 45de481c9..000000000 --- a/zfs/lib/libdmu-ctl/zfs_ctldir.c +++ /dev/null @@ -1,1147 +0,0 @@ -/* - * CDDL HEADER START - * - * The contents of this file are subject to the terms of the - * Common Development and Distribution License (the "License"). - * You may not use this file except in compliance with the License. - * - * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE - * or http://www.opensolaris.org/os/licensing. - * See the License for the specific language governing permissions - * and limitations under the License. - * - * When distributing Covered Code, include this CDDL HEADER in each - * file and include the License file at usr/src/OPENSOLARIS.LICENSE. - * If applicable, add the following below this CDDL HEADER, with the - * fields enclosed by brackets "[]" replaced with your own identifying - * information: Portions Copyright [yyyy] [name of copyright owner] - * - * CDDL HEADER END - */ -/* - * Copyright 2008 Sun Microsystems, Inc. All rights reserved. - * Use is subject to license terms. - */ - -#pragma ident "@(#)zfs_ctldir.c 1.20 08/04/27 SMI" - -/* - * ZFS control directory (a.k.a. ".zfs") - * - * This directory provides a common location for all ZFS meta-objects. - * Currently, this is only the 'snapshot' directory, but this may expand in the - * future. The elements are built using the GFS primitives, as the hierarchy - * does not actually exist on disk. - * - * For 'snapshot', we don't want to have all snapshots always mounted, because - * this would take up a huge amount of space in /etc/mnttab. We have three - * types of objects: - * - * ctldir ------> snapshotdir -------> snapshot - * | - * | - * V - * mounted fs - * - * The 'snapshot' node contains just enough information to lookup '..' and act - * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we - * perform an automount of the underlying filesystem and return the - * corresponding vnode. - * - * All mounts are handled automatically by the kernel, but unmounts are - * (currently) handled from user land. The main reason is that there is no - * reliable way to auto-unmount the filesystem when it's "no longer in use". - * When the user unmounts a filesystem, we call zfsctl_unmount(), which - * unmounts any snapshots within the snapshot directory. - * - * The '.zfs', '.zfs/snapshot', and all directories created under - * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and - * share the same vfs_t as the head filesystem (what '.zfs' lives under). - * - * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>' - * (ie: snapshots) are ZFS nodes and have their own unique vfs_t. - * However, vnodes within these mounted on file systems have their v_vfsp - * fields set to the head filesystem to make NFS happy (see - * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t - * so that it cannot be freed until all snapshots have been unmounted. - */ - -#include <fs/fs_subr.h> -#include <sys/zfs_ctldir.h> -#include <sys/zfs_ioctl.h> -#include <sys/zfs_vfsops.h> -#include <sys/vfs_opreg.h> -#include <sys/gfs.h> -#include <sys/stat.h> -#include <sys/dmu.h> -#include <sys/dsl_deleg.h> -#include <sys/mount.h> -#include <sys/sunddi.h> - -typedef struct zfsctl_node { - gfs_dir_t zc_gfs_private; - uint64_t zc_id; - timestruc_t zc_cmtime; /* ctime and mtime, always the same */ -} zfsctl_node_t; - -typedef struct zfsctl_snapdir { - zfsctl_node_t sd_node; - kmutex_t sd_lock; - avl_tree_t sd_snaps; -} zfsctl_snapdir_t; - -typedef struct { - char *se_name; - vnode_t *se_root; - avl_node_t se_node; -} zfs_snapentry_t; - -static int -snapentry_compare(const void *a, const void *b) -{ - const zfs_snapentry_t *sa = a; - const zfs_snapentry_t *sb = b; - int ret = strcmp(sa->se_name, sb->se_name); - - if (ret < 0) - return (-1); - else if (ret > 0) - return (1); - else - return (0); -} - -vnodeops_t *zfsctl_ops_root; -vnodeops_t *zfsctl_ops_snapdir; -vnodeops_t *zfsctl_ops_snapshot; - -static const fs_operation_def_t zfsctl_tops_root[]; -static const fs_operation_def_t zfsctl_tops_snapdir[]; -static const fs_operation_def_t zfsctl_tops_snapshot[]; - -static vnode_t *zfsctl_mknode_snapdir(vnode_t *); -static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset); -static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *); - -static gfs_opsvec_t zfsctl_opsvec[] = { - { ".zfs", zfsctl_tops_root, &zfsctl_ops_root }, - { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir }, - { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot }, - { NULL } -}; - -/* - * Root directory elements. We have only a single static entry, 'snapshot'. - */ -static gfs_dirent_t zfsctl_root_entries[] = { - { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE }, - { NULL } -}; - -/* include . and .. in the calculation */ -#define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \ - sizeof (gfs_dirent_t)) + 1) - - -/* - * Initialize the various GFS pieces we'll need to create and manipulate .zfs - * directories. This is called from the ZFS init routine, and initializes the - * vnode ops vectors that we'll be using. - */ -void -zfsctl_init(void) -{ - VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0); -} - -void -zfsctl_fini(void) -{ - /* - * Remove vfsctl vnode ops - */ - if (zfsctl_ops_root) - vn_freevnodeops(zfsctl_ops_root); - if (zfsctl_ops_snapdir) - vn_freevnodeops(zfsctl_ops_snapdir); - if (zfsctl_ops_snapshot) - vn_freevnodeops(zfsctl_ops_snapshot); - - zfsctl_ops_root = NULL; - zfsctl_ops_snapdir = NULL; - zfsctl_ops_snapshot = NULL; -} - -/* - * Return the inode number associated with the 'snapshot' directory. - */ -/* ARGSUSED */ -static ino64_t -zfsctl_root_inode_cb(vnode_t *vp, int index) -{ - ASSERT(index == 0); - return (ZFSCTL_INO_SNAPDIR); -} - -/* - * Create the '.zfs' directory. This directory is cached as part of the VFS - * structure. This results in a hold on the vfs_t. The code in zfs_umount() - * therefore checks against a vfs_count of 2 instead of 1. This reference - * is removed when the ctldir is destroyed in the unmount. - */ -void -zfsctl_create(zfsvfs_t *zfsvfs) -{ - vnode_t *vp, *rvp; - zfsctl_node_t *zcp; - - ASSERT(zfsvfs->z_ctldir == NULL); - - vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs, - zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries, - zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL); - zcp = vp->v_data; - zcp->zc_id = ZFSCTL_INO_ROOT; - - VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0); - ZFS_TIME_DECODE(&zcp->zc_cmtime, VTOZ(rvp)->z_phys->zp_crtime); - VN_RELE(rvp); - - /* - * We're only faking the fact that we have a root of a filesystem for - * the sake of the GFS interfaces. Undo the flag manipulation it did - * for us. - */ - vp->v_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT); - - zfsvfs->z_ctldir = vp; -} - -/* - * Destroy the '.zfs' directory. Only called when the filesystem is unmounted. - * There might still be more references if we were force unmounted, but only - * new zfs_inactive() calls can occur and they don't reference .zfs - */ -void -zfsctl_destroy(zfsvfs_t *zfsvfs) -{ - VN_RELE(zfsvfs->z_ctldir); - zfsvfs->z_ctldir = NULL; -} - -/* - * Given a root znode, retrieve the associated .zfs directory. - * Add a hold to the vnode and return it. - */ -vnode_t * -zfsctl_root(znode_t *zp) -{ - ASSERT(zfs_has_ctldir(zp)); - VN_HOLD(zp->z_zfsvfs->z_ctldir); - return (zp->z_zfsvfs->z_ctldir); -} - -/* - * Common open routine. Disallow any write access. - */ -/* ARGSUSED */ -static int -zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct) -{ - if (flags & FWRITE) - return (EACCES); - - return (0); -} - -/* - * Common close routine. Nothing to do here. - */ -/* ARGSUSED */ -static int -zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off, - cred_t *cr, caller_context_t *ct) -{ - return (0); -} - -/* - * Common access routine. Disallow writes. - */ -/* ARGSUSED */ -static int -zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr, - caller_context_t *ct) -{ - if (mode & VWRITE) - return (EACCES); - - return (0); -} - -/* - * Common getattr function. Fill in basic information. - */ -static void -zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) -{ - zfsctl_node_t *zcp = vp->v_data; - timestruc_t now; - - vap->va_uid = 0; - vap->va_gid = 0; - vap->va_rdev = 0; - /* - * We are a purly virtual object, so we have no - * blocksize or allocated blocks. - */ - vap->va_blksize = 0; - vap->va_nblocks = 0; - vap->va_seq = 0; - vap->va_fsid = vp->v_vfsp->vfs_dev; - vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | - S_IROTH | S_IXOTH; - vap->va_type = VDIR; - /* - * We live in the now (for atime). - */ - gethrestime(&now); - vap->va_atime = now; - vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; -} - -/*ARGSUSED*/ -static int -zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - zfsctl_node_t *zcp = vp->v_data; - uint64_t object = zcp->zc_id; - zfid_short_t *zfid; - int i; - - ZFS_ENTER(zfsvfs); - - if (fidp->fid_len < SHORT_FID_LEN) { - fidp->fid_len = SHORT_FID_LEN; - ZFS_EXIT(zfsvfs); - return (ENOSPC); - } - - zfid = (zfid_short_t *)fidp; - - zfid->zf_len = SHORT_FID_LEN; - - for (i = 0; i < sizeof (zfid->zf_object); i++) - zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); - - /* .zfs znodes always have a generation number of 0 */ - for (i = 0; i < sizeof (zfid->zf_gen); i++) - zfid->zf_gen[i] = 0; - - ZFS_EXIT(zfsvfs); - return (0); -} - -/* - * .zfs inode namespace - * - * We need to generate unique inode numbers for all files and directories - * within the .zfs pseudo-filesystem. We use the following scheme: - * - * ENTRY ZFSCTL_INODE - * .zfs 1 - * .zfs/snapshot 2 - * .zfs/snapshot/<snap> objectid(snap) - */ - -#define ZFSCTL_INO_SNAP(id) (id) - -/* - * Get root directory attributes. - */ -/* ARGSUSED */ -static int -zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, - caller_context_t *ct) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - - ZFS_ENTER(zfsvfs); - vap->va_nodeid = ZFSCTL_INO_ROOT; - vap->va_nlink = vap->va_size = NROOT_ENTRIES; - - zfsctl_common_getattr(vp, vap); - ZFS_EXIT(zfsvfs); - - return (0); -} - -/* - * Special case the handling of "..". - */ -/* ARGSUSED */ -int -zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, - int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, - int *direntflags, pathname_t *realpnp) -{ - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - int err; - - /* - * No extended attributes allowed under .zfs - */ - if (flags & LOOKUP_XATTR) - return (EINVAL); - - ZFS_ENTER(zfsvfs); - - if (strcmp(nm, "..") == 0) { - err = VFS_ROOT(dvp->v_vfsp, vpp); - } else { - err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, - cr, ct, direntflags, realpnp); - } - - ZFS_EXIT(zfsvfs); - - return (err); -} - -static const fs_operation_def_t zfsctl_tops_root[] = { - { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, - { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, - { VOPNAME_IOCTL, { .error = fs_inval } }, - { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, - { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, - { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, - { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, - { VOPNAME_SEEK, { .vop_seek = fs_seek } }, - { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, - { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, - { NULL } -}; - -static int -zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) -{ - objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; - - dmu_objset_name(os, zname); - if (strlen(zname) + 1 + strlen(name) >= len) - return (ENAMETOOLONG); - (void) strcat(zname, "@"); - (void) strcat(zname, name); - return (0); -} - -static int -zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) -{ - vnode_t *svp = sep->se_root; - int error; - - ASSERT(vn_ismntpt(svp)); - - /* this will be dropped by dounmount() */ - if ((error = vn_vfswlock(svp)) != 0) - return (error); - - VN_HOLD(svp); - error = dounmount(vn_mountedvfs(svp), fflags, cr); - if (error) { - VN_RELE(svp); - return (error); - } - VFS_RELE(svp->v_vfsp); - /* - * We can't use VN_RELE(), as that will try to invoke - * zfsctl_snapdir_inactive(), which would cause us to destroy - * the sd_lock mutex held by our caller. - */ - ASSERT(svp->v_count == 1); - gfs_vop_inactive(svp, cr, NULL); - - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - kmem_free(sep, sizeof (zfs_snapentry_t)); - - return (0); -} - -static void -zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) -{ - avl_index_t where; - vfs_t *vfsp; - refstr_t *pathref; - char newpath[MAXNAMELEN]; - char *tail; - - ASSERT(MUTEX_HELD(&sdp->sd_lock)); - ASSERT(sep != NULL); - - vfsp = vn_mountedvfs(sep->se_root); - ASSERT(vfsp != NULL); - - vfs_lock_wait(vfsp); - - /* - * Change the name in the AVL tree. - */ - avl_remove(&sdp->sd_snaps, sep); - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); - (void) strcpy(sep->se_name, nm); - VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); - avl_insert(&sdp->sd_snaps, sep, where); - - /* - * Change the current mountpoint info: - * - update the tail of the mntpoint path - * - update the tail of the resource path - */ - pathref = vfs_getmntpoint(vfsp); - (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); - VERIFY((tail = strrchr(newpath, '/')) != NULL); - *(tail+1) = '\0'; - ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); - (void) strcat(newpath, nm); - refstr_rele(pathref); - vfs_setmntpoint(vfsp, newpath); - - pathref = vfs_getresource(vfsp); - (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); - VERIFY((tail = strrchr(newpath, '@')) != NULL); - *(tail+1) = '\0'; - ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); - (void) strcat(newpath, nm); - refstr_rele(pathref); - vfs_setresource(vfsp, newpath); - - vfs_unlock(vfsp); -} - -/*ARGSUSED*/ -static int -zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, - cred_t *cr, caller_context_t *ct, int flags) -{ - zfsctl_snapdir_t *sdp = sdvp->v_data; - zfs_snapentry_t search, *sep; - zfsvfs_t *zfsvfs; - avl_index_t where; - char from[MAXNAMELEN], to[MAXNAMELEN]; - char real[MAXNAMELEN]; - int err; - - zfsvfs = sdvp->v_vfsp->vfs_data; - ZFS_ENTER(zfsvfs); - - if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { - err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, - MAXNAMELEN, NULL); - if (err == 0) { - snm = real; - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); - return (err); - } - } - - ZFS_EXIT(zfsvfs); - - err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from); - if (!err) - err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to); - if (!err) - err = zfs_secpolicy_rename_perms(from, to, cr); - if (err) - return (err); - - /* - * Cannot move snapshots out of the snapdir. - */ - if (sdvp != tdvp) - return (EINVAL); - - if (strcmp(snm, tnm) == 0) - return (0); - - mutex_enter(&sdp->sd_lock); - - search.se_name = (char *)snm; - if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { - mutex_exit(&sdp->sd_lock); - return (ENOENT); - } - - err = dmu_objset_rename(from, to, B_FALSE); - if (err == 0) - zfsctl_rename_snap(sdp, sep, tnm); - - mutex_exit(&sdp->sd_lock); - - return (err); -} - -/* ARGSUSED */ -static int -zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, - caller_context_t *ct, int flags) -{ - zfsctl_snapdir_t *sdp = dvp->v_data; - zfs_snapentry_t *sep; - zfs_snapentry_t search; - zfsvfs_t *zfsvfs; - char snapname[MAXNAMELEN]; - char real[MAXNAMELEN]; - int err; - - zfsvfs = dvp->v_vfsp->vfs_data; - ZFS_ENTER(zfsvfs); - - if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { - - err = dmu_snapshot_realname(zfsvfs->z_os, name, real, - MAXNAMELEN, NULL); - if (err == 0) { - name = real; - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); - return (err); - } - } - - ZFS_EXIT(zfsvfs); - - err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname); - if (!err) - err = zfs_secpolicy_destroy_perms(snapname, cr); - if (err) - return (err); - - mutex_enter(&sdp->sd_lock); - - search.se_name = name; - sep = avl_find(&sdp->sd_snaps, &search, NULL); - if (sep) { - avl_remove(&sdp->sd_snaps, sep); - err = zfsctl_unmount_snap(sep, MS_FORCE, cr); - if (err) - avl_add(&sdp->sd_snaps, sep); - else - err = dmu_objset_destroy(snapname); - } else { - err = ENOENT; - } - - mutex_exit(&sdp->sd_lock); - - return (err); -} - -/* - * This creates a snapshot under '.zfs/snapshot'. - */ -/* ARGSUSED */ -static int -zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, - cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) -{ - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - char name[MAXNAMELEN]; - int err; - static enum symfollow follow = NO_FOLLOW; - static enum uio_seg seg = UIO_SYSSPACE; - - dmu_objset_name(zfsvfs->z_os, name); - - *vpp = NULL; - - err = zfs_secpolicy_snapshot_perms(name, cr); - if (err) - return (err); - - if (err == 0) { - err = dmu_objset_snapshot(name, dirname, B_FALSE); - if (err) - return (err); - err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); - } - - return (err); -} - -/* - * Lookup entry point for the 'snapshot' directory. Try to open the - * snapshot if it exist, creating the pseudo filesystem vnode as necessary. - * Perform a mount of the associated dataset on top of the vnode. - */ -/* ARGSUSED */ -static int -zfsctl_snapdir_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, - int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, - int *direntflags, pathname_t *realpnp) -{ - zfsctl_snapdir_t *sdp = dvp->v_data; - objset_t *snap; - char snapname[MAXNAMELEN]; - char real[MAXNAMELEN]; - char *mountpoint; - zfs_snapentry_t *sep, search; - struct mounta margs; - vfs_t *vfsp; - size_t mountpoint_len; - avl_index_t where; - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - int err; - - /* - * No extended attributes allowed under .zfs - */ - if (flags & LOOKUP_XATTR) - return (EINVAL); - - ASSERT(dvp->v_type == VDIR); - - if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) - return (0); - - /* - * If we get a recursive call, that means we got called - * from the domount() code while it was trying to look up the - * spec (which looks like a local path for zfs). We need to - * add some flag to domount() to tell it not to do this lookup. - */ - if (MUTEX_HELD(&sdp->sd_lock)) - return (ENOENT); - - ZFS_ENTER(zfsvfs); - - if (flags & FIGNORECASE) { - boolean_t conflict = B_FALSE; - - err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, - MAXNAMELEN, &conflict); - if (err == 0) { - nm = real; - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); - return (err); - } - if (realpnp) - (void) strlcpy(realpnp->pn_buf, nm, - realpnp->pn_bufsize); - if (conflict && direntflags) - *direntflags = ED_CASE_CONFLICT; - } - - mutex_enter(&sdp->sd_lock); - search.se_name = (char *)nm; - if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { - *vpp = sep->se_root; - VN_HOLD(*vpp); - err = traverse(vpp); - if (err) { - VN_RELE(*vpp); - *vpp = NULL; - } else if (*vpp == sep->se_root) { - /* - * The snapshot was unmounted behind our backs, - * try to remount it. - */ - goto domount; - } else { - /* - * VROOT was set during the traverse call. We need - * to clear it since we're pretending to be part - * of our parent's vfs. - */ - (*vpp)->v_flag &= ~VROOT; - } - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); - return (err); - } - - /* - * The requested snapshot is not currently mounted, look it up. - */ - err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname); - if (err) { - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); - return (err); - } - if (dmu_objset_open(snapname, DMU_OST_ZFS, - DS_MODE_STANDARD | DS_MODE_READONLY, &snap) != 0) { - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); - return (ENOENT); - } - - sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); - sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); - (void) strcpy(sep->se_name, nm); - *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); - avl_insert(&sdp->sd_snaps, sep, where); - - dmu_objset_close(snap); -domount: - mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) + - strlen("/.zfs/snapshot/") + strlen(nm) + 1; - mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); - (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s", - refstr_value(dvp->v_vfsp->vfs_mntpt), nm); - - margs.spec = snapname; - margs.dir = mountpoint; - margs.flags = MS_SYSSPACE | MS_NOMNTTAB; - margs.fstype = "zfs"; - margs.dataptr = NULL; - margs.datalen = 0; - margs.optptr = NULL; - margs.optlen = 0; - - err = domount("zfs", &margs, *vpp, kcred, &vfsp); - kmem_free(mountpoint, mountpoint_len); - - if (err == 0) { - /* - * Return the mounted root rather than the covered mount point. - * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns - * the ZFS vnode mounted on top of the GFS node. This ZFS - * vnode is the root the newly created vfsp. - */ - VFS_RELE(vfsp); - err = traverse(vpp); - } - - if (err == 0) { - /* - * Fix up the root vnode mounted on .zfs/snapshot/<snapname>. - * - * This is where we lie about our v_vfsp in order to - * make .zfs/snapshot/<snapname> accessible over NFS - * without requiring manual mounts of <snapname>. - */ - ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); - VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; - (*vpp)->v_vfsp = zfsvfs->z_vfs; - (*vpp)->v_flag &= ~VROOT; - } - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); - - /* - * If we had an error, drop our hold on the vnode and - * zfsctl_snapshot_inactive() will clean up. - */ - if (err) { - VN_RELE(*vpp); - *vpp = NULL; - } - return (err); -} - -/* ARGSUSED */ -static int -zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, - offset_t *offp, offset_t *nextp, void *data, int flags) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - char snapname[MAXNAMELEN]; - uint64_t id, cookie; - boolean_t case_conflict; - int error; - - ZFS_ENTER(zfsvfs); - - cookie = *offp; - error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id, - &cookie, &case_conflict); - if (error) { - ZFS_EXIT(zfsvfs); - if (error == ENOENT) { - *eofp = 1; - return (0); - } - return (error); - } - - if (flags & V_RDDIR_ENTFLAGS) { - edirent_t *eodp = dp; - - (void) strcpy(eodp->ed_name, snapname); - eodp->ed_ino = ZFSCTL_INO_SNAP(id); - eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; - } else { - struct dirent64 *odp = dp; - - (void) strcpy(odp->d_name, snapname); - odp->d_ino = ZFSCTL_INO_SNAP(id); - } - *nextp = cookie; - - ZFS_EXIT(zfsvfs); - - return (0); -} - -/* - * pvp is the '.zfs' directory (zfsctl_node_t). - * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). - * - * This function is the callback to create a GFS vnode for '.zfs/snapshot' - * when a lookup is performed on .zfs for "snapshot". - */ -vnode_t * -zfsctl_mknode_snapdir(vnode_t *pvp) -{ - vnode_t *vp; - zfsctl_snapdir_t *sdp; - - vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, - zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, - zfsctl_snapdir_readdir_cb, NULL); - sdp = vp->v_data; - sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; - sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; - mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); - avl_create(&sdp->sd_snaps, snapentry_compare, - sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); - return (vp); -} - -/* ARGSUSED */ -static int -zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, - caller_context_t *ct) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - zfsctl_snapdir_t *sdp = vp->v_data; - - ZFS_ENTER(zfsvfs); - zfsctl_common_getattr(vp, vap); - vap->va_nodeid = gfs_file_inode(vp); - vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; - ZFS_EXIT(zfsvfs); - - return (0); -} - -/* ARGSUSED */ -static void -zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct) -{ - zfsctl_snapdir_t *sdp = vp->v_data; - void *private; - - private = gfs_dir_inactive(vp); - if (private != NULL) { - ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); - mutex_destroy(&sdp->sd_lock); - avl_destroy(&sdp->sd_snaps); - kmem_free(private, sizeof (zfsctl_snapdir_t)); - } -} - -static const fs_operation_def_t zfsctl_tops_snapdir[] = { - { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, - { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, - { VOPNAME_IOCTL, { .error = fs_inval } }, - { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, - { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, - { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, - { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, - { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, - { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, - { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, - { VOPNAME_SEEK, { .vop_seek = fs_seek } }, - { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, - { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, - { NULL } -}; - -/* - * pvp is the GFS vnode '.zfs/snapshot'. - * - * This creates a GFS node under '.zfs/snapshot' representing each - * snapshot. This newly created GFS node is what we mount snapshot - * vfs_t's ontop of. - */ -static vnode_t * -zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) -{ - vnode_t *vp; - zfsctl_node_t *zcp; - - vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, - zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); - zcp = vp->v_data; - zcp->zc_id = objset; - VFS_HOLD(vp->v_vfsp); - - return (vp); -} - -static void -zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct) -{ - zfsctl_snapdir_t *sdp; - zfs_snapentry_t *sep, *next; - vnode_t *dvp; - - VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); - sdp = dvp->v_data; - - mutex_enter(&sdp->sd_lock); - - if (vp->v_count > 1) { - mutex_exit(&sdp->sd_lock); - return; - } - ASSERT(!vn_ismntpt(vp)); - - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - next = AVL_NEXT(&sdp->sd_snaps, sep); - - if (sep->se_root == vp) { - avl_remove(&sdp->sd_snaps, sep); - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - kmem_free(sep, sizeof (zfs_snapentry_t)); - break; - } - sep = next; - } - ASSERT(sep != NULL); - - mutex_exit(&sdp->sd_lock); - VN_RELE(dvp); - VFS_RELE(vp->v_vfsp); - - /* - * Dispose of the vnode for the snapshot mount point. - * This is safe to do because once this entry has been removed - * from the AVL tree, it can't be found again, so cannot become - * "active". If we lookup the same name again we will end up - * creating a new vnode. - */ - gfs_vop_inactive(vp, cr, ct); -} - - -/* - * These VP's should never see the light of day. They should always - * be covered. - */ -static const fs_operation_def_t zfsctl_tops_snapshot[] = { - VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive }, - NULL, NULL -}; - -int -zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) -{ - zfsvfs_t *zfsvfs = vfsp->vfs_data; - vnode_t *dvp, *vp; - zfsctl_snapdir_t *sdp; - zfsctl_node_t *zcp; - zfs_snapentry_t *sep; - int error; - - ASSERT(zfsvfs->z_ctldir != NULL); - error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, - NULL, 0, NULL, kcred, NULL, NULL, NULL); - if (error != 0) - return (error); - sdp = dvp->v_data; - - mutex_enter(&sdp->sd_lock); - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - vp = sep->se_root; - zcp = vp->v_data; - if (zcp->zc_id == objsetid) - break; - - sep = AVL_NEXT(&sdp->sd_snaps, sep); - } - - if (sep != NULL) { - VN_HOLD(vp); - /* - * Return the mounted root rather than the covered mount point. - * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> - * and returns the ZFS vnode mounted on top of the GFS node. - * This ZFS vnode is the root of the vfs for objset 'objsetid'. - */ - error = traverse(&vp); - if (error == 0) { - if (vp == sep->se_root) - error = EINVAL; - else - *zfsvfsp = VTOZ(vp)->z_zfsvfs; - } - mutex_exit(&sdp->sd_lock); - VN_RELE(vp); - } else { - error = EINVAL; - mutex_exit(&sdp->sd_lock); - } - - VN_RELE(dvp); - - return (error); -} - -/* - * Unmount any snapshots for the given filesystem. This is called from - * zfs_umount() - if we have a ctldir, then go through and unmount all the - * snapshots. - */ -int -zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) -{ - zfsvfs_t *zfsvfs = vfsp->vfs_data; - vnode_t *dvp; - zfsctl_snapdir_t *sdp; - zfs_snapentry_t *sep, *next; - int error; - - ASSERT(zfsvfs->z_ctldir != NULL); - error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, - NULL, 0, NULL, cr, NULL, NULL, NULL); - if (error != 0) - return (error); - sdp = dvp->v_data; - - mutex_enter(&sdp->sd_lock); - - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - next = AVL_NEXT(&sdp->sd_snaps, sep); - - /* - * If this snapshot is not mounted, then it must - * have just been unmounted by somebody else, and - * will be cleaned up by zfsctl_snapdir_inactive(). - */ - if (vn_ismntpt(sep->se_root)) { - avl_remove(&sdp->sd_snaps, sep); - error = zfsctl_unmount_snap(sep, fflags, cr); - if (error) { - avl_add(&sdp->sd_snaps, sep); - break; - } - } - sep = next; - } - - mutex_exit(&sdp->sd_lock); - VN_RELE(dvp); - - return (error); -} |