libzfs_changelist.c revision 94de1d4cf6ec0a3bf040dcc4b8df107c4ed36b51
/*
* 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 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <libintl.h>
#include <libuutil.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zone.h>
#include <libzfs.h>
#include "libzfs_impl.h"
/*
* Structure to keep track of dataset state. Before changing the 'sharenfs' or
* 'mountpoint' property, we record whether the filesystem was previously
* mounted/shared. This prior state dictates whether we remount/reshare the
* dataset after the property has been changed.
*
* The interface consists of the following sequence of functions:
*
* changelist_gather()
* changelist_prefix()
* < change property >
* changelist_postfix()
* changelist_free()
*
* Other interfaces:
*
* changelist_remove() - remove a node from a gathered list
* changelist_rename() - renames all datasets appropriately when doing a rename
* changelist_unshare() - unshares all the nodes in a given changelist
* changelist_haszonedchild() - check if there is any child exported to
* a local zone
*/
typedef struct prop_changenode {
zfs_handle_t *cn_handle;
int cn_shared;
int cn_mounted;
int cn_zoned;
uu_list_node_t cn_listnode;
} prop_changenode_t;
struct prop_changelist {
zfs_prop_t cl_prop;
zfs_prop_t cl_realprop;
uu_list_pool_t *cl_pool;
uu_list_t *cl_list;
boolean_t cl_waslegacy;
boolean_t cl_allchildren;
boolean_t cl_alldependents;
int cl_flags;
boolean_t cl_haszonedchild;
};
/*
* If the property is 'mountpoint', go through and unmount filesystems as
* necessary. We don't do the same for 'sharenfs', because we can just re-share
* with different options without interrupting service.
*/
int
changelist_prefix(prop_changelist_t *clp)
{
prop_changenode_t *cn;
int ret = 0;
if (clp->cl_prop != ZFS_PROP_MOUNTPOINT)
return (0);
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
/*
* if we are in a global zone, but this dataset is exported to
* a local zone, do nothing.
*/
if ((getzoneid() == GLOBAL_ZONEID) && cn->cn_zoned)
continue;
/*
* If we have a volume and this was a rename, remove the
* /dev/zvol links
*/
if (cn->cn_handle->zfs_volblocksize &&
clp->cl_realprop == ZFS_PROP_NAME) {
if (zvol_remove_link(cn->cn_handle->zfs_hdl,
cn->cn_handle->zfs_name) != 0)
ret = -1;
} else if (zfs_unmount(cn->cn_handle, NULL, clp->cl_flags) != 0)
ret = -1;
}
return (ret);
}
/*
* If the proeprty is 'mountpoint' or 'sharenfs', go through and remount and/or
* reshare the filesystems as necessary. In changelist_gather() we recorded
* whether the filesystem was previously shared or mounted. The action we take
* depends on the previous state, and whether the value was previously 'legacy'.
* For non-legacy properties, we only remount/reshare the filesystem if it was
* previously mounted/shared. Otherwise, we always remount/reshare the
* filesystem.
*/
int
changelist_postfix(prop_changelist_t *clp)
{
prop_changenode_t *cn;
int ret = 0;
/*
* If we're changing the mountpoint, attempt to destroy the underlying
* mountpoint. All other datasets will have inherited from this dataset
* (in which case their mountpoints exist in the filesystem in the new
* location), or have explicit mountpoints set (in which case they won't
* be in the changelist).
*/
if ((cn = uu_list_last(clp->cl_list)) == NULL)
return (0);
if (clp->cl_prop == ZFS_PROP_MOUNTPOINT)
remove_mountpoint(cn->cn_handle);
/*
* We walk the datasets in reverse, because we want to mount any parent
* datasets before mounting the children.
*/
for (cn = uu_list_last(clp->cl_list); cn != NULL;
cn = uu_list_prev(clp->cl_list, cn)) {
/*
* if we are in a global zone, but this dataset is exported to
* a local zone, do nothing.
*/
if ((getzoneid() == GLOBAL_ZONEID) && cn->cn_zoned)
continue;
zfs_refresh_properties(cn->cn_handle);
/*
* If this is a volume and we're doing a rename, recreate the
* /dev/zvol links.
*/
if (cn->cn_handle->zfs_volblocksize &&
clp->cl_realprop == ZFS_PROP_NAME) {
if (zvol_create_link(cn->cn_handle->zfs_hdl,
cn->cn_handle->zfs_name) != 0)
ret = -1;
continue;
}
if ((clp->cl_waslegacy || cn->cn_mounted) &&
!zfs_is_mounted(cn->cn_handle, NULL) &&
zfs_mount(cn->cn_handle, NULL, 0) != 0)
ret = -1;
/*
* We always re-share even if the filesystem is currently
* shared, so that we can adopt any new options.
*/
if ((cn->cn_shared ||
(clp->cl_prop == ZFS_PROP_SHARENFS && clp->cl_waslegacy))) {
char shareopts[ZFS_MAXPROPLEN];
if (zfs_prop_get(cn->cn_handle, ZFS_PROP_SHARENFS,
shareopts, sizeof (shareopts), NULL, NULL, 0,
B_FALSE) == 0 && strcmp(shareopts, "off") == 0)
ret = zfs_unshare(cn->cn_handle, NULL);
else
ret = zfs_share(cn->cn_handle);
}
}
return (ret);
}
/*
* Is this "dataset" a child of "parent"?
*/
static boolean_t
isa_child_of(char *dataset, const char *parent)
{
int len;
/* snapshot does not have a child */
if (strchr(parent, '@'))
return (B_FALSE);
len = strlen(parent);
if (strncmp(dataset, parent, len) == 0 &&
(dataset[len] == '/' || dataset[len] == '\0'))
return (B_TRUE);
else
return (B_FALSE);
}
/*
* If we rename a filesystem, and child filesystem handles are no longer valid,
* since we identify datasets by their name in the ZFS namespace. So, we have
* to go through and fix up all the names appropriately. We could do this
* automatically if libzfs kept track of all open handles, but this is a lot
* less work.
*/
void
changelist_rename(prop_changelist_t *clp, const char *src, const char *dst)
{
prop_changenode_t *cn;
char newname[ZFS_MAXNAMELEN];
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
/*
* Do not rename a clone that's not in the source hierarchy.
*/
if (!isa_child_of(cn->cn_handle->zfs_name, src))
continue;
/*
* Destroy the previous mountpoint if needed.
*/
remove_mountpoint(cn->cn_handle);
(void) strlcpy(newname, dst, sizeof (newname));
(void) strcat(newname, cn->cn_handle->zfs_name + strlen(src));
(void) strlcpy(cn->cn_handle->zfs_name, newname,
sizeof (cn->cn_handle->zfs_name));
}
}
/*
* Given a gathered changelist for the "sharenfs" property,
* unshare all the nodes in the list.
*/
int
changelist_unshare(prop_changelist_t *clp)
{
prop_changenode_t *cn;
int ret = 0;
if (clp->cl_prop != ZFS_PROP_SHARENFS)
return (0);
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
if (zfs_unshare(cn->cn_handle, NULL) != 0)
ret = -1;
}
return (ret);
}
/*
* Check if there is any child exported to a local zone in a
* given changelist. This information has already been recorded
* while gathering the changelist via changelist_gather().
*/
int
changelist_haszonedchild(prop_changelist_t *clp)
{
return (clp->cl_haszonedchild);
}
/*
* Remove a node from a gathered list.
*/
void
changelist_remove(zfs_handle_t *zhp, prop_changelist_t *clp)
{
prop_changenode_t *cn;
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
if (strcmp(cn->cn_handle->zfs_name, zhp->zfs_name) == 0) {
uu_list_remove(clp->cl_list, cn);
zfs_close(cn->cn_handle);
free(cn);
return;
}
}
}
/*
* Release any memory associated with a changelist.
*/
void
changelist_free(prop_changelist_t *clp)
{
prop_changenode_t *cn;
uu_list_walk_t *walk;
if (clp->cl_list) {
verify((walk = uu_list_walk_start(clp->cl_list,
UU_WALK_ROBUST)) != NULL);
while ((cn = uu_list_walk_next(walk)) != NULL) {
uu_list_remove(clp->cl_list, cn);
zfs_close(cn->cn_handle);
free(cn);
}
uu_list_walk_end(walk);
uu_list_destroy(clp->cl_list);
}
if (clp->cl_pool)
uu_list_pool_destroy(clp->cl_pool);
free(clp);
}
static int
change_one(zfs_handle_t *zhp, void *data)
{
prop_changelist_t *clp = data;
char property[ZFS_MAXPROPLEN];
char where[64];
prop_changenode_t *cn;
zfs_source_t sourcetype;
/*
* We only want to unmount/unshare those filesystems which may
* inherit from the target filesystem. If we find any filesystem
* with a locally set mountpoint, we ignore any children since changing
* the property will not affect them. If this is a rename, we iterate
* over all children regardless, since we need them unmounted in order
* to do the rename. Also, if this is a volume and we're doing a
* rename, then always add it to the changelist.
*/
if (!(zhp->zfs_volblocksize && clp->cl_realprop == ZFS_PROP_NAME) &&
zfs_prop_get(zhp, clp->cl_prop, property,
sizeof (property), &sourcetype, where, sizeof (where),
B_FALSE) != 0) {
zfs_close(zhp);
return (0);
}
if (clp->cl_alldependents || clp->cl_allchildren ||
sourcetype == ZFS_SRC_DEFAULT || sourcetype == ZFS_SRC_INHERITED) {
if ((cn = zfs_alloc(zfs_get_handle(zhp),
sizeof (prop_changenode_t))) == NULL) {
zfs_close(zhp);
return (-1);
}
cn->cn_handle = zhp;
cn->cn_mounted = zfs_is_mounted(zhp, NULL);
cn->cn_shared = zfs_is_shared(zhp, NULL);
cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
/* indicate if any child is exported to a local zone */
if ((getzoneid() == GLOBAL_ZONEID) && cn->cn_zoned)
clp->cl_haszonedchild = B_TRUE;
uu_list_node_init(cn, &cn->cn_listnode, clp->cl_pool);
if (clp->cl_alldependents) {
verify(uu_list_insert_after(clp->cl_list,
uu_list_last(clp->cl_list), cn) == 0);
return (0);
} else {
verify(uu_list_insert_before(clp->cl_list,
uu_list_first(clp->cl_list), cn) == 0);
return (zfs_iter_children(zhp, change_one, data));
}
} else {
zfs_close(zhp);
}
return (0);
}
/*
* Given a ZFS handle and a property, construct a complete list of datasets that
* need to be modified as part of this process. For anything but the
* 'mountpoint' and 'sharenfs' properties, this just returns an empty list.
* Otherwise, we iterate over all children and look for any datasets which
* inherit this property. For each such dataset, we add it to the list and mark
* whether it was shared beforehand.
*/
prop_changelist_t *
changelist_gather(zfs_handle_t *zhp, zfs_prop_t prop, int flags)
{
prop_changelist_t *clp;
prop_changenode_t *cn;
zfs_handle_t *temp;
char property[ZFS_MAXPROPLEN];
if ((clp = zfs_alloc(zhp->zfs_hdl, sizeof (prop_changelist_t))) == NULL)
return (NULL);
clp->cl_pool = uu_list_pool_create("changelist_pool",
sizeof (prop_changenode_t),
offsetof(prop_changenode_t, cn_listnode),
NULL, 0);
if (clp->cl_pool == NULL) {
assert(uu_error() == UU_ERROR_NO_MEMORY);
(void) zfs_error(zhp->zfs_hdl, EZFS_NOMEM, "internal error");
changelist_free(clp);
return (NULL);
}
clp->cl_list = uu_list_create(clp->cl_pool, NULL, 0);
clp->cl_flags = flags;
if (clp->cl_list == NULL) {
assert(uu_error() == UU_ERROR_NO_MEMORY);
(void) zfs_error(zhp->zfs_hdl, EZFS_NOMEM, "internal error");
changelist_free(clp);
return (NULL);
}
/*
* If this is a rename or the 'zoned' property, we pretend we're
* changing the mountpoint and flag it so we can catch all children in
* change_one().
*
* Flag cl_alldependents to catch all children plus the
* dependents (clones) that are not in the hierarchy.
*/
if (prop == ZFS_PROP_NAME) {
clp->cl_prop = ZFS_PROP_MOUNTPOINT;
clp->cl_alldependents = B_TRUE;
} else if (prop == ZFS_PROP_ZONED) {
clp->cl_prop = ZFS_PROP_MOUNTPOINT;
clp->cl_allchildren = B_TRUE;
} else {
clp->cl_prop = prop;
}
clp->cl_realprop = prop;
if (clp->cl_prop != ZFS_PROP_MOUNTPOINT &&
clp->cl_prop != ZFS_PROP_SHARENFS)
return (clp);
if (clp->cl_alldependents) {
if (zfs_iter_dependents(zhp, change_one, clp) != 0) {
changelist_free(clp);
return (NULL);
}
} else if (zfs_iter_children(zhp, change_one, clp) != 0) {
changelist_free(clp);
return (NULL);
}
/*
* We have to re-open ourselves because we auto-close all the handles
* and can't tell the difference.
*/
if ((temp = zfs_open(zhp->zfs_hdl, zfs_get_name(zhp),
ZFS_TYPE_ANY)) == NULL) {
changelist_free(clp);
return (NULL);
}
/*
* Always add ourself to the list. We add ourselves to the end so that
* we're the last to be unmounted.
*/
if ((cn = zfs_alloc(zhp->zfs_hdl,
sizeof (prop_changenode_t))) == NULL) {
zfs_close(temp);
changelist_free(clp);
return (NULL);
}
cn->cn_handle = temp;
cn->cn_mounted = zfs_is_mounted(temp, NULL);
cn->cn_shared = zfs_is_shared(temp, NULL);
cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
uu_list_node_init(cn, &cn->cn_listnode, clp->cl_pool);
verify(uu_list_insert_after(clp->cl_list,
uu_list_last(clp->cl_list), cn) == 0);
/*
* If the property was previously 'legacy' or 'none', record this fact,
* as the behavior of changelist_postfix() will be different.
*/
if (zfs_prop_get(zhp, prop, property, sizeof (property),
NULL, NULL, 0, B_FALSE) == 0 &&
(strcmp(property, "legacy") == 0 || strcmp(property, "none") == 0 ||
strcmp(property, "off") == 0))
clp->cl_waslegacy = B_TRUE;
return (clp);
}