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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/amd64/compile/hs32/modules/usr/src/sys/modules/syscons/dragon/@/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c |
/*
* 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
* All rights reserved.
*/
/*
* 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 <sys/zfs_context.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_vfsops.h>
#include <sys/namei.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>
#include "zfs_namecheck.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);
}
#ifdef sun
vnodeops_t *zfsctl_ops_root;
vnodeops_t *zfsctl_ops_snapdir;
vnodeops_t *zfsctl_ops_snapshot;
vnodeops_t *zfsctl_ops_shares;
vnodeops_t *zfsctl_ops_shares_dir;
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 const fs_operation_def_t zfsctl_tops_shares[];
#else /* !sun */
static struct vop_vector zfsctl_ops_root;
static struct vop_vector zfsctl_ops_snapdir;
static struct vop_vector zfsctl_ops_snapshot;
static struct vop_vector zfsctl_ops_shares;
static struct vop_vector zfsctl_ops_shares_dir;
#endif /* !sun */
static vnode_t *zfsctl_mknode_snapdir(vnode_t *);
static vnode_t *zfsctl_mknode_shares(vnode_t *);
static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset);
static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *);
#ifdef sun
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 },
{ ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir },
{ ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares },
{ NULL }
};
#endif /* sun */
/*
* Root directory elements. We only have two entries
* snapshot and shares.
*/
static gfs_dirent_t zfsctl_root_entries[] = {
{ "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE },
{ "shares", zfsctl_mknode_shares, 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)
{
#ifdef sun
VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0);
#endif
}
void
zfsctl_fini(void)
{
#ifdef sun
/*
* 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);
if (zfsctl_ops_shares)
vn_freevnodeops(zfsctl_ops_shares);
if (zfsctl_ops_shares_dir)
vn_freevnodeops(zfsctl_ops_shares_dir);
zfsctl_ops_root = NULL;
zfsctl_ops_snapdir = NULL;
zfsctl_ops_snapshot = NULL;
zfsctl_ops_shares = NULL;
zfsctl_ops_shares_dir = NULL;
#endif /* sun */
}
boolean_t
zfsctl_is_node(vnode_t *vp)
{
return (vn_matchops(vp, zfsctl_ops_root) ||
vn_matchops(vp, zfsctl_ops_snapdir) ||
vn_matchops(vp, zfsctl_ops_snapshot) ||
vn_matchops(vp, zfsctl_ops_shares) ||
vn_matchops(vp, zfsctl_ops_shares_dir));
}
/*
* Return the inode number associated with the 'snapshot' or
* 'shares' directory.
*/
/* ARGSUSED */
static ino64_t
zfsctl_root_inode_cb(vnode_t *vp, int index)
{
zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
ASSERT(index <= 2);
if (index == 0)
return (ZFSCTL_INO_SNAPDIR);
return (zfsvfs->z_shares_dir);
}
/*
* 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;
uint64_t crtime[2];
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, LK_EXCLUSIVE, &rvp) == 0);
VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
&crtime, sizeof (crtime)));
ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime);
VN_URELE(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_vflag &= ~VV_ROOT;
zfsvfs->z_ctldir = vp;
VOP_UNLOCK(vp, 0);
}
/*
* 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(struct vop_open_args *ap)
{
int flags = ap->a_mode;
if (flags & FWRITE)
return (EACCES);
return (0);
}
/*
* Common close routine. Nothing to do here.
*/
/* ARGSUSED */
static int
zfsctl_common_close(struct vop_close_args *ap)
{
return (0);
}
/*
* Common access routine. Disallow writes.
*/
/* ARGSUSED */
static int
zfsctl_common_access(ap)
struct vop_access_args /* {
struct vnode *a_vp;
accmode_t a_accmode;
struct ucred *a_cred;
struct thread *a_td;
} */ *ap;
{
accmode_t accmode = ap->a_accmode;
#ifdef TODO
if (flags & V_ACE_MASK) {
if (accmode & ACE_ALL_WRITE_PERMS)
return (EACCES);
} else {
#endif
if (accmode & VWRITE)
return (EACCES);
#ifdef TODO
}
#endif
return (0);
}
/*
* Common getattr function. Fill in basic information.
*/
static void
zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
{
timestruc_t now;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_rdev = 0;
/*
* We are a purely 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_mount->mnt_stat.f_fsid.val[0];
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;
/* FreeBSD: Reset chflags(2) flags. */
vap->va_flags = 0;
}
/*ARGSUSED*/
static int
zfsctl_common_fid(ap)
struct vop_fid_args /* {
struct vnode *a_vp;
struct fid *a_fid;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
fid_t *fidp = (void *)ap->a_fid;
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);
fidp->fid_len = SHORT_FID_LEN;
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);
}
/*ARGSUSED*/
static int
zfsctl_shares_fid(ap)
struct vop_fid_args /* {
struct vnode *a_vp;
struct fid *a_fid;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
fid_t *fidp = (void *)ap->a_fid;
zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
znode_t *dzp;
int error;
ZFS_ENTER(zfsvfs);
if (zfsvfs->z_shares_dir == 0) {
ZFS_EXIT(zfsvfs);
return (ENOTSUP);
}
if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
error = VOP_FID(ZTOV(dzp), fidp);
VN_RELE(ZTOV(dzp));
}
ZFS_EXIT(zfsvfs);
return (error);
}
static int
zfsctl_common_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
/*
* Destroy the vm object and flush associated pages.
*/
vnode_destroy_vobject(vp);
VI_LOCK(vp);
vp->v_data = NULL;
VI_UNLOCK(vp);
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(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
zfsctl_node_t *zcp = vp->v_data;
ZFS_ENTER(zfsvfs);
vap->va_nodeid = ZFSCTL_INO_ROOT;
vap->va_nlink = vap->va_size = NROOT_ENTRIES;
vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
vap->va_birthtime = vap->va_ctime;
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, LK_EXCLUSIVE, vpp);
if (err == 0)
VOP_UNLOCK(*vpp, 0);
} else {
err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
cr, ct, direntflags, realpnp);
}
ZFS_EXIT(zfsvfs);
return (err);
}
#ifdef sun
static int
zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
caller_context_t *ct)
{
/*
* We only care about ACL_ENABLED so that libsec can
* display ACL correctly and not default to POSIX draft.
*/
if (cmd == _PC_ACL_ENABLED) {
*valp = _ACL_ACE_ENABLED;
return (0);
}
return (fs_pathconf(vp, cmd, valp, cr, ct));
}
#endif /* sun */
#ifdef sun
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_PATHCONF, { .vop_pathconf = zfsctl_pathconf } },
{ VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
{ NULL }
};
#endif /* sun */
/*
* Special case the handling of "..".
*/
/* ARGSUSED */
int
zfsctl_freebsd_root_lookup(ap)
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
vnode_t *dvp = ap->a_dvp;
vnode_t **vpp = ap->a_vpp;
cred_t *cr = ap->a_cnp->cn_cred;
int flags = ap->a_cnp->cn_flags;
int nameiop = ap->a_cnp->cn_nameiop;
char nm[NAME_MAX + 1];
int err;
if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE))
return (EOPNOTSUPP);
ASSERT(ap->a_cnp->cn_namelen < sizeof(nm));
strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1);
err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL);
if (err == 0 && (nm[0] != '.' || nm[1] != '\0'))
vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
return (err);
}
static struct vop_vector zfsctl_ops_root = {
.vop_default = &default_vnodeops,
.vop_open = zfsctl_common_open,
.vop_close = zfsctl_common_close,
.vop_ioctl = VOP_EINVAL,
.vop_getattr = zfsctl_root_getattr,
.vop_access = zfsctl_common_access,
.vop_readdir = gfs_vop_readdir,
.vop_lookup = zfsctl_freebsd_root_lookup,
.vop_inactive = gfs_vop_inactive,
.vop_reclaim = zfsctl_common_reclaim,
#ifdef TODO
.vop_pathconf = zfsctl_pathconf,
#endif
.vop_fid = zfsctl_common_fid,
};
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;
if (snapshot_namecheck(name, NULL, NULL) != 0)
return (EILSEQ);
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);
#ifdef sun
VN_HOLD(svp);
error = dounmount(vn_mountedvfs(svp), fflags, cr);
if (error) {
VN_RELE(svp);
return (error);
}
/*
* 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);
#else /* !sun */
return (dounmount(vn_mountedvfs(svp), fflags, curthread));
#endif /* !sun */
}
#ifdef sun
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, 0);
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, 0);
vfs_unlock(vfsp);
}
#endif /* sun */
#ifdef sun
/*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, 0);
if (err == 0)
zfsctl_rename_snap(sdp, sep, tnm);
mutex_exit(&sdp->sd_lock);
return (err);
}
#endif /* sun */
#ifdef sun
/* 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_index_t where;
if (avl_find(&sdp->sd_snaps, sep, &where) == NULL)
avl_insert(&sdp->sd_snaps, sep, where);
} else
err = dmu_objset_destroy(snapname, B_FALSE);
} else {
err = ENOENT;
}
mutex_exit(&sdp->sd_lock);
return (err);
}
#endif /* sun */
/*
* 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;
if (snapshot_namecheck(dirname, NULL, NULL) != 0)
return (EILSEQ);
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, NULL, NULL,
B_FALSE, B_FALSE, -1);
if (err)
return (err);
err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
}
return (err);
}
static int
zfsctl_freebsd_snapdir_mkdir(ap)
struct vop_mkdir_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
ASSERT(ap->a_cnp->cn_flags & SAVENAME);
return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL,
ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL));
}
/*
* 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 */
int
zfsctl_snapdir_lookup(ap)
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
vnode_t *dvp = ap->a_dvp;
vnode_t **vpp = ap->a_vpp;
struct componentname *cnp = ap->a_cnp;
char nm[NAME_MAX + 1];
zfsctl_snapdir_t *sdp = dvp->v_data;
objset_t *snap;
char snapname[MAXNAMELEN];
char real[MAXNAMELEN];
char *mountpoint;
zfs_snapentry_t *sep, search;
size_t mountpoint_len;
avl_index_t where;
zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
int err;
int flags = 0;
/*
* No extended attributes allowed under .zfs
*/
if (flags & LOOKUP_XATTR)
return (EINVAL);
ASSERT(ap->a_cnp->cn_namelen < sizeof(nm));
strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1);
ASSERT(dvp->v_type == VDIR);
*vpp = NULL;
/*
* 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 (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
ZFS_EXIT(zfsvfs);
return (0);
}
if (flags & FIGNORECASE) {
boolean_t conflict = B_FALSE;
err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
MAXNAMELEN, &conflict);
if (err == 0) {
strlcpy(nm, real, sizeof(nm));
} else if (err != ENOTSUP) {
ZFS_EXIT(zfsvfs);
return (err);
}
#if 0
if (realpnp)
(void) strlcpy(realpnp->pn_buf, nm,
realpnp->pn_bufsize);
if (conflict && direntflags)
*direntflags = ED_CASE_CONFLICT;
#endif
}
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, LK_EXCLUSIVE | LK_RETRY);
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);
/*
* handle "ls *" or "?" in a graceful manner,
* forcing EILSEQ to ENOENT.
* Since shell ultimately passes "*" or "?" as name to lookup
*/
return (err == EILSEQ ? ENOENT : err);
}
if (dmu_objset_hold(snapname, FTAG, &snap) != 0) {
mutex_exit(&sdp->sd_lock);
/* Translate errors and add SAVENAME when needed. */
if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) {
err = EJUSTRETURN;
cnp->cn_flags |= SAVENAME;
} else {
err = ENOENT;
}
ZFS_EXIT(zfsvfs);
return (err);
}
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));
VN_HOLD(*vpp);
avl_insert(&sdp->sd_snaps, sep, where);
dmu_objset_rele(snap, FTAG);
domount:
mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) +
strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1;
mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
(void) snprintf(mountpoint, mountpoint_len,
"%s/" ZFS_CTLDIR_NAME "/snapshot/%s",
dvp->v_vfsp->mnt_stat.f_mntonname, nm);
err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0);
kmem_free(mountpoint, mountpoint_len);
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;
}
mutex_exit(&sdp->sd_lock);
ZFS_EXIT(zfsvfs);
if (err != 0)
*vpp = NULL;
return (err);
}
/* ARGSUSED */
int
zfsctl_shares_lookup(ap)
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
vnode_t *dvp = ap->a_dvp;
vnode_t **vpp = ap->a_vpp;
struct componentname *cnp = ap->a_cnp;
zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
char nm[NAME_MAX + 1];
znode_t *dzp;
int error;
ZFS_ENTER(zfsvfs);
ASSERT(cnp->cn_namelen < sizeof(nm));
strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1);
if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
ZFS_EXIT(zfsvfs);
return (0);
}
if (zfsvfs->z_shares_dir == 0) {
ZFS_EXIT(zfsvfs);
return (ENOTSUP);
}
if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0)
error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp);
VN_RELE(ZTOV(dzp));
ZFS_EXIT(zfsvfs);
return (error);
}
/* 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);
}
/* ARGSUSED */
static int
zfsctl_shares_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *a_ncookies;
u_long **a_cookies;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
uio_t *uiop = ap->a_uio;
cred_t *cr = ap->a_cred;
int *eofp = ap->a_eofflag;
zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
znode_t *dzp;
int error;
ZFS_ENTER(zfsvfs);
if (zfsvfs->z_shares_dir == 0) {
ZFS_EXIT(zfsvfs);
return (ENOTSUP);
}
if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY);
error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies);
VN_URELE(ZTOV(dzp));
} else {
*eofp = 1;
error = ENOENT;
}
ZFS_EXIT(zfsvfs);
return (error);
}
/*
* 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, pvp->v_vfsp,
&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));
VOP_UNLOCK(vp, 0);
return (vp);
}
vnode_t *
zfsctl_mknode_shares(vnode_t *pvp)
{
vnode_t *vp;
zfsctl_node_t *sdp;
vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp,
&zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
NULL, NULL);
sdp = vp->v_data;
sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
VOP_UNLOCK(vp, 0);
return (vp);
}
/* ARGSUSED */
static int
zfsctl_shares_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct thread *a_td;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
vattr_t *vap = ap->a_vap;
cred_t *cr = ap->a_cred;
zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
znode_t *dzp;
int error;
ZFS_ENTER(zfsvfs);
if (zfsvfs->z_shares_dir == 0) {
ZFS_EXIT(zfsvfs);
return (ENOTSUP);
}
if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY);
error = VOP_GETATTR(ZTOV(dzp), vap, cr);
VN_URELE(ZTOV(dzp));
}
ZFS_EXIT(zfsvfs);
return (error);
}
/* ARGSUSED */
static int
zfsctl_snapdir_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
vattr_t *vap = ap->a_vap;
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;
vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os);
vap->va_birthtime = vap->va_ctime;
ZFS_EXIT(zfsvfs);
return (0);
}
/* ARGSUSED */
static int
zfsctl_snapdir_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
zfsctl_snapdir_t *sdp = vp->v_data;
zfs_snapentry_t *sep;
/*
* On forced unmount we have to free snapshots from here.
*/
mutex_enter(&sdp->sd_lock);
while ((sep = avl_first(&sdp->sd_snaps)) != NULL) {
avl_remove(&sdp->sd_snaps, sep);
kmem_free(sep->se_name, strlen(sep->se_name) + 1);
kmem_free(sep, sizeof (zfs_snapentry_t));
}
mutex_exit(&sdp->sd_lock);
gfs_dir_inactive(vp);
ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
mutex_destroy(&sdp->sd_lock);
avl_destroy(&sdp->sd_snaps);
kmem_free(sdp, sizeof (zfsctl_snapdir_t));
return (0);
}
#ifdef sun
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 }
};
static const fs_operation_def_t zfsctl_tops_shares[] = {
{ VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
{ VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
{ VOPNAME_IOCTL, { .error = fs_inval } },
{ VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } },
{ VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
{ VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } },
{ VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } },
{ VOPNAME_SEEK, { .vop_seek = fs_seek } },
{ VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
{ VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } },
{ NULL }
};
#else /* !sun */
static struct vop_vector zfsctl_ops_snapdir = {
.vop_default = &default_vnodeops,
.vop_open = zfsctl_common_open,
.vop_close = zfsctl_common_close,
.vop_ioctl = VOP_EINVAL,
.vop_getattr = zfsctl_snapdir_getattr,
.vop_access = zfsctl_common_access,
.vop_mkdir = zfsctl_freebsd_snapdir_mkdir,
.vop_readdir = gfs_vop_readdir,
.vop_lookup = zfsctl_snapdir_lookup,
.vop_inactive = zfsctl_snapdir_inactive,
.vop_reclaim = zfsctl_common_reclaim,
.vop_fid = zfsctl_common_fid,
};
static struct vop_vector zfsctl_ops_shares = {
.vop_default = &default_vnodeops,
.vop_open = zfsctl_common_open,
.vop_close = zfsctl_common_close,
.vop_ioctl = VOP_EINVAL,
.vop_getattr = zfsctl_shares_getattr,
.vop_access = zfsctl_common_access,
.vop_readdir = zfsctl_shares_readdir,
.vop_lookup = zfsctl_shares_lookup,
.vop_inactive = gfs_vop_inactive,
.vop_reclaim = zfsctl_common_reclaim,
.vop_fid = zfsctl_shares_fid,
};
#endif /* !sun */
/*
* 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, pvp->v_vfsp,
&zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
VN_HOLD(vp);
zcp = vp->v_data;
zcp->zc_id = objset;
VOP_UNLOCK(vp, 0);
return (vp);
}
static int
zfsctl_snapshot_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
cred_t *cr = ap->a_td->td_ucred;
struct vop_inactive_args iap;
zfsctl_snapdir_t *sdp;
zfs_snapentry_t *sep, *next;
int locked;
vnode_t *dvp;
if (vp->v_count > 0)
goto end;
VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
sdp = dvp->v_data;
VOP_UNLOCK(dvp, 0);
if (!(locked = MUTEX_HELD(&sdp->sd_lock)))
mutex_enter(&sdp->sd_lock);
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);
if (!locked)
mutex_exit(&sdp->sd_lock);
VN_RELE(dvp);
end:
/*
* 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.
*/
iap.a_vp = vp;
return (gfs_vop_inactive(&iap));
}
static int
zfsctl_traverse_begin(vnode_t **vpp, int lktype)
{
VN_HOLD(*vpp);
/* Snapshot should be already mounted, but just in case. */
if (vn_mountedvfs(*vpp) == NULL)
return (ENOENT);
return (traverse(vpp, lktype));
}
static void
zfsctl_traverse_end(vnode_t *vp, int err)
{
if (err == 0)
vput(vp);
else
VN_RELE(vp);
}
static int
zfsctl_snapshot_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
int err;
err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY);
if (err == 0)
err = VOP_GETATTR(vp, ap->a_vap, ap->a_cred);
zfsctl_traverse_end(vp, err);
return (err);
}
static int
zfsctl_snapshot_fid(ap)
struct vop_fid_args /* {
struct vnode *a_vp;
struct fid *a_fid;
} */ *ap;
{
vnode_t *vp = ap->a_vp;
int err;
err = zfsctl_traverse_begin(&vp, LK_SHARED | LK_RETRY);
if (err == 0)
err = VOP_VPTOFH(vp, (void *)ap->a_fid);
zfsctl_traverse_end(vp, err);
return (err);
}
static int
zfsctl_snapshot_lookup(ap)
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
vnode_t *dvp = ap->a_dvp;
vnode_t **vpp = ap->a_vpp;
struct componentname *cnp = ap->a_cnp;
cred_t *cr = ap->a_cnp->cn_cred;
zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
int error;
if (cnp->cn_namelen != 2 || cnp->cn_nameptr[0] != '.' ||
cnp->cn_nameptr[1] != '.') {
return (ENOENT);
}
ASSERT(dvp->v_type == VDIR);
ASSERT(zfsvfs->z_ctldir != NULL);
error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", vpp,
NULL, 0, NULL, cr, NULL, NULL, NULL);
if (error == 0)
vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
return (error);
}
static int
zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap)
{
zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data;
vnode_t *dvp, *vp;
zfsctl_snapdir_t *sdp;
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;
if (vp == ap->a_vp)
break;
sep = AVL_NEXT(&sdp->sd_snaps, sep);
}
if (sep == NULL) {
mutex_exit(&sdp->sd_lock);
error = ENOENT;
} else {
size_t len;
len = strlen(sep->se_name);
*ap->a_buflen -= len;
bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len);
mutex_exit(&sdp->sd_lock);
vref(dvp);
*ap->a_vpp = dvp;
}
VN_RELE(dvp);
return (error);
}
/*
* These VP's should never see the light of day. They should always
* be covered.
*/
static struct vop_vector zfsctl_ops_snapshot = {
.vop_default = &default_vnodeops,
.vop_inactive = zfsctl_snapshot_inactive,
.vop_lookup = zfsctl_snapshot_lookup,
.vop_reclaim = zfsctl_common_reclaim,
.vop_getattr = zfsctl_snapshot_getattr,
.vop_fid = zfsctl_snapshot_fid,
.vop_vptocnp = zfsctl_snapshot_vptocnp,
};
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, LK_SHARED | LK_RETRY);
if (error == 0) {
if (vp == sep->se_root)
error = EINVAL;
else
*zfsvfsp = VTOZ(vp)->z_zfsvfs;
}
mutex_exit(&sdp->sd_lock);
if (error == 0)
VN_URELE(vp);
else
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)) {
error = zfsctl_unmount_snap(sep, fflags, cr);
if (error) {
avl_index_t where;
/*
* Before reinserting snapshot to the tree,
* check if it was actually removed. For example
* when snapshot mount point is busy, we will
* have an error here, but there will be no need
* to reinsert snapshot.
*/
if (avl_find(&sdp->sd_snaps, sep, &where) == NULL)
avl_insert(&sdp->sd_snaps, sep, where);
break;
}
}
sep = next;
}
mutex_exit(&sdp->sd_lock);
VN_RELE(dvp);
return (error);
}