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| Current File : //usr/src/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Portions Copyright 2007 Ramprakash Jelari
*
* Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
* All rights reserved.
*/
#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;
boolean_t cn_needpost; /* is postfix() needed? */
uu_list_node_t cn_listnode;
} prop_changenode_t;
struct prop_changelist {
zfs_prop_t cl_prop;
zfs_prop_t cl_realprop;
zfs_prop_t cl_shareprop; /* used with sharenfs/sharesmb */
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_mflags; /* Mount flags */
int cl_gflags; /* Gather request flags */
boolean_t cl_haszonedchild;
boolean_t cl_sorted;
};
/*
* 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. We do handle 'sharesmb'
* since there may be old resource names that need to be removed.
*/
int
changelist_prefix(prop_changelist_t *clp)
{
prop_changenode_t *cn;
int ret = 0;
if (clp->cl_prop != ZFS_PROP_MOUNTPOINT &&
clp->cl_prop != ZFS_PROP_SHARESMB)
return (0);
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
/* if a previous loop failed, set the remaining to false */
if (ret == -1) {
cn->cn_needpost = B_FALSE;
continue;
}
/*
* If we are in the global zone, but this dataset is exported
* to a local zone, do nothing.
*/
if (getzoneid() == GLOBAL_ZONEID && cn->cn_zoned)
continue;
if (!ZFS_IS_VOLUME(cn->cn_handle)) {
/*
* Do the property specific processing.
*/
switch (clp->cl_prop) {
case ZFS_PROP_MOUNTPOINT:
if (clp->cl_gflags & CL_GATHER_DONT_UNMOUNT)
break;
if (zfs_unmount(cn->cn_handle, NULL,
clp->cl_mflags) != 0) {
ret = -1;
cn->cn_needpost = B_FALSE;
}
break;
case ZFS_PROP_SHARESMB:
(void) zfs_unshare_smb(cn->cn_handle, NULL);
break;
}
}
}
if (ret == -1)
(void) changelist_postfix(clp);
return (ret);
}
/*
* If the property 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;
char shareopts[ZFS_MAXPROPLEN];
int errors = 0;
libzfs_handle_t *hdl;
/*
* 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 &&
!(clp->cl_gflags & CL_GATHER_DONT_UNMOUNT)) {
remove_mountpoint(cn->cn_handle);
}
/*
* It is possible that the changelist_prefix() used libshare
* to unshare some entries. Since libshare caches data, an
* attempt to reshare during postfix can fail unless libshare
* is uninitialized here so that it will reinitialize later.
*/
if (cn->cn_handle != NULL) {
hdl = cn->cn_handle->zfs_hdl;
assert(hdl != NULL);
zfs_uninit_libshare(hdl);
}
/*
* We walk the datasets in reverse, because we want to mount any parent
* datasets before mounting the children. We walk all datasets even if
* there are errors.
*/
for (cn = uu_list_last(clp->cl_list); cn != NULL;
cn = uu_list_prev(clp->cl_list, cn)) {
boolean_t sharenfs;
boolean_t sharesmb;
boolean_t mounted;
/*
* If we are in the global zone, but this dataset is exported
* to a local zone, do nothing.
*/
if (getzoneid() == GLOBAL_ZONEID && cn->cn_zoned)
continue;
/* Only do post-processing if it's required */
if (!cn->cn_needpost)
continue;
cn->cn_needpost = B_FALSE;
zfs_refresh_properties(cn->cn_handle);
if (ZFS_IS_VOLUME(cn->cn_handle))
continue;
/*
* Remount if previously mounted or mountpoint was legacy,
* or sharenfs or sharesmb property is set.
*/
sharenfs = ((zfs_prop_get(cn->cn_handle, ZFS_PROP_SHARENFS,
shareopts, sizeof (shareopts), NULL, NULL, 0,
B_FALSE) == 0) && (strcmp(shareopts, "off") != 0));
sharesmb = ((zfs_prop_get(cn->cn_handle, ZFS_PROP_SHARESMB,
shareopts, sizeof (shareopts), NULL, NULL, 0,
B_FALSE) == 0) && (strcmp(shareopts, "off") != 0));
mounted = (clp->cl_gflags & CL_GATHER_DONT_UNMOUNT) ||
zfs_is_mounted(cn->cn_handle, NULL);
if (!mounted && (cn->cn_mounted ||
((sharenfs || sharesmb || clp->cl_waslegacy) &&
(zfs_prop_get_int(cn->cn_handle,
ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_ON)))) {
if (zfs_mount(cn->cn_handle, NULL, 0) != 0)
errors++;
else
mounted = TRUE;
}
/*
* If the file system is mounted we always re-share even
* if the filesystem is currently shared, so that we can
* adopt any new options.
*/
if (sharenfs && mounted)
errors += zfs_share_nfs(cn->cn_handle);
else if (cn->cn_shared || clp->cl_waslegacy)
errors += zfs_unshare_nfs(cn->cn_handle, NULL);
if (sharesmb && mounted)
errors += zfs_share_smb(cn->cn_handle);
else if (cn->cn_shared || clp->cl_waslegacy)
errors += zfs_unshare_smb(cn->cn_handle, NULL);
}
return (errors ? -1 : 0);
}
/*
* Is this "dataset" a child of "parent"?
*/
boolean_t
isa_child_of(const char *dataset, const char *parent)
{
int len;
len = strlen(parent);
if (strncmp(dataset, parent, len) == 0 &&
(dataset[len] == '@' || dataset[len] == '/' ||
dataset[len] == '\0'))
return (B_TRUE);
else
return (B_FALSE);
}
/*
* If we rename a filesystem, child filesystem handles are no longer valid
* since we identify each dataset by its name in the ZFS namespace. As a
* result, 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' or 'sharesmb' property,
* unshare all the datasets in the list.
*/
int
changelist_unshare(prop_changelist_t *clp, zfs_share_proto_t *proto)
{
prop_changenode_t *cn;
int ret = 0;
if (clp->cl_prop != ZFS_PROP_SHARENFS &&
clp->cl_prop != ZFS_PROP_SHARESMB)
return (0);
for (cn = uu_list_first(clp->cl_list); cn != NULL;
cn = uu_list_next(clp->cl_list, cn)) {
if (zfs_unshare_proto(cn->cn_handle, NULL, proto) != 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(prop_changelist_t *clp, const char *name)
{
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, 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;
void *cookie;
if (clp->cl_list) {
cookie = NULL;
while ((cn = uu_list_teardown(clp->cl_list, &cookie)) != NULL) {
zfs_close(cn->cn_handle);
free(cn);
}
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;
zprop_source_t sourcetype;
zprop_source_t share_sourcetype;
/*
* We only want to unmount/unshare those filesystems that 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 (!(ZFS_IS_VOLUME(zhp) && 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 we are "watching" sharenfs or sharesmb
* then check out the companion property which is tracked
* in cl_shareprop
*/
if (clp->cl_shareprop != ZPROP_INVAL &&
zfs_prop_get(zhp, clp->cl_shareprop, property,
sizeof (property), &share_sourcetype, where, sizeof (where),
B_FALSE) != 0) {
zfs_close(zhp);
return (0);
}
if (clp->cl_alldependents || clp->cl_allchildren ||
sourcetype == ZPROP_SRC_DEFAULT ||
sourcetype == ZPROP_SRC_INHERITED ||
(clp->cl_shareprop != ZPROP_INVAL &&
(share_sourcetype == ZPROP_SRC_DEFAULT ||
share_sourcetype == ZPROP_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 = (clp->cl_gflags & CL_GATHER_MOUNT_ALWAYS) ||
zfs_is_mounted(zhp, NULL);
cn->cn_shared = zfs_is_shared(zhp);
cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
cn->cn_needpost = B_TRUE;
/* 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_sorted) {
uu_list_index_t idx;
(void) uu_list_find(clp->cl_list, cn, NULL,
&idx);
uu_list_insert(clp->cl_list, cn, idx);
} else {
/*
* Add this child to beginning of the list. Children
* below this one in the hierarchy will get added above
* this one in the list. This produces a list in
* reverse dataset name order.
* This is necessary when the original mountpoint
* is legacy or none.
*/
verify(uu_list_insert_before(clp->cl_list,
uu_list_first(clp->cl_list), cn) == 0);
}
if (!clp->cl_alldependents)
return (zfs_iter_children(zhp, change_one, data));
} else {
zfs_close(zhp);
}
return (0);
}
/*ARGSUSED*/
static int
compare_mountpoints(const void *a, const void *b, void *unused)
{
const prop_changenode_t *ca = a;
const prop_changenode_t *cb = b;
char mounta[MAXPATHLEN];
char mountb[MAXPATHLEN];
boolean_t hasmounta, hasmountb;
/*
* When unsharing or unmounting filesystems, we need to do it in
* mountpoint order. This allows the user to have a mountpoint
* hierarchy that is different from the dataset hierarchy, and still
* allow it to be changed. However, if either dataset doesn't have a
* mountpoint (because it is a volume or a snapshot), we place it at the
* end of the list, because it doesn't affect our change at all.
*/
hasmounta = (zfs_prop_get(ca->cn_handle, ZFS_PROP_MOUNTPOINT, mounta,
sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
hasmountb = (zfs_prop_get(cb->cn_handle, ZFS_PROP_MOUNTPOINT, mountb,
sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
if (!hasmounta && hasmountb)
return (-1);
else if (hasmounta && !hasmountb)
return (1);
else if (!hasmounta && !hasmountb)
return (0);
else
return (strcmp(mountb, mounta));
}
/*
* 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 that
* inherit the 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 gather_flags,
int mnt_flags)
{
prop_changelist_t *clp;
prop_changenode_t *cn;
zfs_handle_t *temp;
char property[ZFS_MAXPROPLEN];
uu_compare_fn_t *compare = NULL;
boolean_t legacy = B_FALSE;
if ((clp = zfs_alloc(zhp->zfs_hdl, sizeof (prop_changelist_t))) == NULL)
return (NULL);
/*
* For mountpoint-related tasks, we want to sort everything by
* mountpoint, so that we mount and unmount them in the appropriate
* order, regardless of their position in the hierarchy.
*/
if (prop == ZFS_PROP_NAME || prop == ZFS_PROP_ZONED ||
prop == ZFS_PROP_MOUNTPOINT || prop == ZFS_PROP_SHARENFS ||
prop == ZFS_PROP_SHARESMB) {
if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT,
property, sizeof (property),
NULL, NULL, 0, B_FALSE) == 0 &&
(strcmp(property, "legacy") == 0 ||
strcmp(property, "none") == 0)) {
legacy = B_TRUE;
}
if (!legacy) {
compare = compare_mountpoints;
clp->cl_sorted = B_TRUE;
}
}
clp->cl_pool = uu_list_pool_create("changelist_pool",
sizeof (prop_changenode_t),
offsetof(prop_changenode_t, cn_listnode),
compare, 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,
clp->cl_sorted ? UU_LIST_SORTED : 0);
clp->cl_gflags = gather_flags;
clp->cl_mflags = mnt_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 if (prop == ZFS_PROP_CANMOUNT) {
clp->cl_prop = ZFS_PROP_MOUNTPOINT;
} else if (prop == ZFS_PROP_VOLSIZE) {
clp->cl_prop = ZFS_PROP_MOUNTPOINT;
} else {
clp->cl_prop = prop;
}
clp->cl_realprop = prop;
if (clp->cl_prop != ZFS_PROP_MOUNTPOINT &&
clp->cl_prop != ZFS_PROP_SHARENFS &&
clp->cl_prop != ZFS_PROP_SHARESMB)
return (clp);
/*
* If watching SHARENFS or SHARESMB then
* also watch its companion property.
*/
if (clp->cl_prop == ZFS_PROP_SHARENFS)
clp->cl_shareprop = ZFS_PROP_SHARESMB;
else if (clp->cl_prop == ZFS_PROP_SHARESMB)
clp->cl_shareprop = ZFS_PROP_SHARENFS;
if (clp->cl_alldependents) {
if (zfs_iter_dependents(zhp, B_TRUE, 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_DATASET)) == 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 = (clp->cl_gflags & CL_GATHER_MOUNT_ALWAYS) ||
zfs_is_mounted(temp, NULL);
cn->cn_shared = zfs_is_shared(temp);
cn->cn_zoned = zfs_prop_get_int(zhp, ZFS_PROP_ZONED);
cn->cn_needpost = B_TRUE;
uu_list_node_init(cn, &cn->cn_listnode, clp->cl_pool);
if (clp->cl_sorted) {
uu_list_index_t idx;
(void) uu_list_find(clp->cl_list, cn, NULL, &idx);
uu_list_insert(clp->cl_list, cn, idx);
} else {
/*
* Add the target dataset to the end of the list.
* The list is not really unsorted. The list will be
* in reverse dataset name order. This is necessary
* when the original mountpoint is legacy or none.
*/
verify(uu_list_insert_after(clp->cl_list,
uu_list_last(clp->cl_list), cn) == 0);
}
/*
* If the mountpoint property was previously 'legacy', or 'none',
* record it as the behavior of changelist_postfix() will be different.
*/
if ((clp->cl_prop == ZFS_PROP_MOUNTPOINT) && legacy) {
/*
* do not automatically mount ex-legacy datasets if
* we specifically set canmount to noauto
*/
if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) !=
ZFS_CANMOUNT_NOAUTO)
clp->cl_waslegacy = B_TRUE;
}
return (clp);
}