mirror_zfs/lib/libzfs/libzfs_iter.c
Paul Dagnelie 30af21b025 Implement Redacted Send/Receive
Redacted send/receive allows users to send subsets of their data to 
a target system. One possible use case for this feature is to not 
transmit sensitive information to a data warehousing, test/dev, or 
analytics environment. Another is to save space by not replicating 
unimportant data within a given dataset, for example in backup tools 
like zrepl.

Redacted send/receive is a three-stage process. First, a clone (or 
clones) is made of the snapshot to be sent to the target. In this 
clone (or clones), all unnecessary or unwanted data is removed or
modified. This clone is then snapshotted to create the "redaction 
snapshot" (or snapshots). Second, the new zfs redact command is used 
to create a redaction bookmark. The redaction bookmark stores the 
list of blocks in a snapshot that were modified by the redaction 
snapshot(s). Finally, the redaction bookmark is passed as a parameter 
to zfs send. When sending to the snapshot that was redacted, the
redaction bookmark is used to filter out blocks that contain sensitive 
or unwanted information, and those blocks are not included in the send 
stream.  When sending from the redaction bookmark, the blocks it 
contains are considered as candidate blocks in addition to those 
blocks in the destination snapshot that were modified since the 
creation_txg of the redaction bookmark.  This step is necessary to 
allow the target to rehydrate data in the case where some blocks are 
accidentally or unnecessarily modified in the redaction snapshot.

The changes to bookmarks to enable fast space estimation involve 
adding deadlists to bookmarks. There is also logic to manage the 
life cycles of these deadlists.

The new size estimation process operates in cases where previously 
an accurate estimate could not be provided. In those cases, a send 
is performed where no data blocks are read, reducing the runtime 
significantly and providing a byte-accurate size estimate.

Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Chris Williamson <chris.williamson@delphix.com>
Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #7958
2019-06-19 09:48:12 -07:00

601 lines
14 KiB
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) 2013, 2019 by Delphix. All rights reserved.
* Copyright 2014 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2019 Datto Inc.
*/
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <stddef.h>
#include <libintl.h>
#include <libzfs.h>
#include <libzutil.h>
#include <sys/mntent.h>
#include "libzfs_impl.h"
int
zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
nvlist_t *nvl = zfs_get_clones_nvl(zhp);
nvpair_t *pair;
if (nvl == NULL)
return (0);
for (pair = nvlist_next_nvpair(nvl, NULL); pair != NULL;
pair = nvlist_next_nvpair(nvl, pair)) {
zfs_handle_t *clone = zfs_open(zhp->zfs_hdl, nvpair_name(pair),
ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME);
if (clone != NULL) {
int err = func(clone, data);
if (err != 0)
return (err);
}
}
return (0);
}
static int
zfs_do_list_ioctl(zfs_handle_t *zhp, int arg, zfs_cmd_t *zc)
{
int rc;
uint64_t orig_cookie;
orig_cookie = zc->zc_cookie;
top:
(void) strlcpy(zc->zc_name, zhp->zfs_name, sizeof (zc->zc_name));
rc = ioctl(zhp->zfs_hdl->libzfs_fd, arg, zc);
if (rc == -1) {
switch (errno) {
case ENOMEM:
/* expand nvlist memory and try again */
if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, zc) != 0) {
zcmd_free_nvlists(zc);
return (-1);
}
zc->zc_cookie = orig_cookie;
goto top;
/*
* An errno value of ESRCH indicates normal completion.
* If ENOENT is returned, then the underlying dataset
* has been removed since we obtained the handle.
*/
case ESRCH:
case ENOENT:
rc = 1;
break;
default:
rc = zfs_standard_error(zhp->zfs_hdl, errno,
dgettext(TEXT_DOMAIN,
"cannot iterate filesystems"));
break;
}
}
return (rc);
}
/*
* Iterate over all child filesystems
*/
int
zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
zfs_cmd_t zc = {"\0"};
zfs_handle_t *nzhp;
int ret;
if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM)
return (0);
if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
return (-1);
while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_DATASET_LIST_NEXT,
&zc)) == 0) {
/*
* Silently ignore errors, as the only plausible explanation is
* that the pool has since been removed.
*/
if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl,
&zc)) == NULL) {
continue;
}
if ((ret = func(nzhp, data)) != 0) {
zcmd_free_nvlists(&zc);
return (ret);
}
}
zcmd_free_nvlists(&zc);
return ((ret < 0) ? ret : 0);
}
/*
* Iterate over all snapshots
*/
int
zfs_iter_snapshots(zfs_handle_t *zhp, boolean_t simple, zfs_iter_f func,
void *data, uint64_t min_txg, uint64_t max_txg)
{
zfs_cmd_t zc = {"\0"};
zfs_handle_t *nzhp;
int ret;
nvlist_t *range_nvl = NULL;
if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT ||
zhp->zfs_type == ZFS_TYPE_BOOKMARK)
return (0);
zc.zc_simple = simple;
if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
return (-1);
if (min_txg != 0) {
range_nvl = fnvlist_alloc();
fnvlist_add_uint64(range_nvl, SNAP_ITER_MIN_TXG, min_txg);
}
if (max_txg != 0) {
if (range_nvl == NULL)
range_nvl = fnvlist_alloc();
fnvlist_add_uint64(range_nvl, SNAP_ITER_MAX_TXG, max_txg);
}
if (range_nvl != NULL &&
zcmd_write_src_nvlist(zhp->zfs_hdl, &zc, range_nvl) != 0) {
zcmd_free_nvlists(&zc);
fnvlist_free(range_nvl);
return (-1);
}
while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_SNAPSHOT_LIST_NEXT,
&zc)) == 0) {
if (simple)
nzhp = make_dataset_simple_handle_zc(zhp, &zc);
else
nzhp = make_dataset_handle_zc(zhp->zfs_hdl, &zc);
if (nzhp == NULL)
continue;
if ((ret = func(nzhp, data)) != 0) {
zcmd_free_nvlists(&zc);
fnvlist_free(range_nvl);
return (ret);
}
}
zcmd_free_nvlists(&zc);
fnvlist_free(range_nvl);
return ((ret < 0) ? ret : 0);
}
/*
* Iterate over all bookmarks
*/
int
zfs_iter_bookmarks(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
zfs_handle_t *nzhp;
nvlist_t *props = NULL;
nvlist_t *bmarks = NULL;
int err;
nvpair_t *pair;
if ((zfs_get_type(zhp) & (ZFS_TYPE_SNAPSHOT | ZFS_TYPE_BOOKMARK)) != 0)
return (0);
/* Setup the requested properties nvlist. */
props = fnvlist_alloc();
for (zfs_prop_t p = 0; p < ZFS_NUM_PROPS; p++) {
if (zfs_prop_valid_for_type(p, ZFS_TYPE_BOOKMARK, B_FALSE)) {
fnvlist_add_boolean(props, zfs_prop_to_name(p));
}
}
fnvlist_add_boolean(props, "redact_complete");
if ((err = lzc_get_bookmarks(zhp->zfs_name, props, &bmarks)) != 0)
goto out;
for (pair = nvlist_next_nvpair(bmarks, NULL);
pair != NULL; pair = nvlist_next_nvpair(bmarks, pair)) {
char name[ZFS_MAX_DATASET_NAME_LEN];
char *bmark_name;
nvlist_t *bmark_props;
bmark_name = nvpair_name(pair);
bmark_props = fnvpair_value_nvlist(pair);
if (snprintf(name, sizeof (name), "%s#%s", zhp->zfs_name,
bmark_name) >= sizeof (name)) {
err = EINVAL;
goto out;
}
nzhp = make_bookmark_handle(zhp, name, bmark_props);
if (nzhp == NULL)
continue;
if ((err = func(nzhp, data)) != 0)
goto out;
}
out:
fnvlist_free(props);
fnvlist_free(bmarks);
return (err);
}
/*
* Routines for dealing with the sorted snapshot functionality
*/
typedef struct zfs_node {
zfs_handle_t *zn_handle;
avl_node_t zn_avlnode;
} zfs_node_t;
static int
zfs_sort_snaps(zfs_handle_t *zhp, void *data)
{
avl_tree_t *avl = data;
zfs_node_t *node;
zfs_node_t search;
search.zn_handle = zhp;
node = avl_find(avl, &search, NULL);
if (node) {
/*
* If this snapshot was renamed while we were creating the
* AVL tree, it's possible that we already inserted it under
* its old name. Remove the old handle before adding the new
* one.
*/
zfs_close(node->zn_handle);
avl_remove(avl, node);
free(node);
}
node = zfs_alloc(zhp->zfs_hdl, sizeof (zfs_node_t));
node->zn_handle = zhp;
avl_add(avl, node);
return (0);
}
static int
zfs_snapshot_compare(const void *larg, const void *rarg)
{
zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
uint64_t lcreate, rcreate;
/*
* Sort them according to creation time. We use the hidden
* CREATETXG property to get an absolute ordering of snapshots.
*/
lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
return (AVL_CMP(lcreate, rcreate));
}
int
zfs_iter_snapshots_sorted(zfs_handle_t *zhp, zfs_iter_f callback, void *data,
uint64_t min_txg, uint64_t max_txg)
{
int ret = 0;
zfs_node_t *node;
avl_tree_t avl;
void *cookie = NULL;
avl_create(&avl, zfs_snapshot_compare,
sizeof (zfs_node_t), offsetof(zfs_node_t, zn_avlnode));
ret = zfs_iter_snapshots(zhp, B_FALSE, zfs_sort_snaps, &avl, min_txg,
max_txg);
for (node = avl_first(&avl); node != NULL; node = AVL_NEXT(&avl, node))
ret |= callback(node->zn_handle, data);
while ((node = avl_destroy_nodes(&avl, &cookie)) != NULL)
free(node);
avl_destroy(&avl);
return (ret);
}
typedef struct {
char *ssa_first;
char *ssa_last;
boolean_t ssa_seenfirst;
boolean_t ssa_seenlast;
zfs_iter_f ssa_func;
void *ssa_arg;
} snapspec_arg_t;
static int
snapspec_cb(zfs_handle_t *zhp, void *arg)
{
snapspec_arg_t *ssa = arg;
const char *shortsnapname;
int err = 0;
if (ssa->ssa_seenlast)
return (0);
shortsnapname = strchr(zfs_get_name(zhp), '@') + 1;
if (!ssa->ssa_seenfirst && strcmp(shortsnapname, ssa->ssa_first) == 0)
ssa->ssa_seenfirst = B_TRUE;
if (strcmp(shortsnapname, ssa->ssa_last) == 0)
ssa->ssa_seenlast = B_TRUE;
if (ssa->ssa_seenfirst) {
err = ssa->ssa_func(zhp, ssa->ssa_arg);
} else {
zfs_close(zhp);
}
return (err);
}
/*
* spec is a string like "A,B%C,D"
*
* <snaps>, where <snaps> can be:
* <snap> (single snapshot)
* <snap>%<snap> (range of snapshots, inclusive)
* %<snap> (range of snapshots, starting with earliest)
* <snap>% (range of snapshots, ending with last)
* % (all snapshots)
* <snaps>[,...] (comma separated list of the above)
*
* If a snapshot can not be opened, continue trying to open the others, but
* return ENOENT at the end.
*/
int
zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
zfs_iter_f func, void *arg)
{
char *buf, *comma_separated, *cp;
int err = 0;
int ret = 0;
buf = zfs_strdup(fs_zhp->zfs_hdl, spec_orig);
cp = buf;
while ((comma_separated = strsep(&cp, ",")) != NULL) {
char *pct = strchr(comma_separated, '%');
if (pct != NULL) {
snapspec_arg_t ssa = { 0 };
ssa.ssa_func = func;
ssa.ssa_arg = arg;
if (pct == comma_separated)
ssa.ssa_seenfirst = B_TRUE;
else
ssa.ssa_first = comma_separated;
*pct = '\0';
ssa.ssa_last = pct + 1;
/*
* If there is a lastname specified, make sure it
* exists.
*/
if (ssa.ssa_last[0] != '\0') {
char snapname[ZFS_MAX_DATASET_NAME_LEN];
(void) snprintf(snapname, sizeof (snapname),
"%s@%s", zfs_get_name(fs_zhp),
ssa.ssa_last);
if (!zfs_dataset_exists(fs_zhp->zfs_hdl,
snapname, ZFS_TYPE_SNAPSHOT)) {
ret = ENOENT;
continue;
}
}
err = zfs_iter_snapshots_sorted(fs_zhp,
snapspec_cb, &ssa, 0, 0);
if (ret == 0)
ret = err;
if (ret == 0 && (!ssa.ssa_seenfirst ||
(ssa.ssa_last[0] != '\0' && !ssa.ssa_seenlast))) {
ret = ENOENT;
}
} else {
char snapname[ZFS_MAX_DATASET_NAME_LEN];
zfs_handle_t *snap_zhp;
(void) snprintf(snapname, sizeof (snapname), "%s@%s",
zfs_get_name(fs_zhp), comma_separated);
snap_zhp = make_dataset_handle(fs_zhp->zfs_hdl,
snapname);
if (snap_zhp == NULL) {
ret = ENOENT;
continue;
}
err = func(snap_zhp, arg);
if (ret == 0)
ret = err;
}
}
free(buf);
return (ret);
}
/*
* Iterate over all children, snapshots and filesystems
* Process snapshots before filesystems because they are nearer the input
* handle: this is extremely important when used with zfs_iter_f functions
* looking for data, following the logic that we would like to find it as soon
* and as close as possible.
*/
int
zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
int ret;
if ((ret = zfs_iter_snapshots(zhp, B_FALSE, func, data, 0, 0)) != 0)
return (ret);
return (zfs_iter_filesystems(zhp, func, data));
}
typedef struct iter_stack_frame {
struct iter_stack_frame *next;
zfs_handle_t *zhp;
} iter_stack_frame_t;
typedef struct iter_dependents_arg {
boolean_t first;
boolean_t allowrecursion;
iter_stack_frame_t *stack;
zfs_iter_f func;
void *data;
} iter_dependents_arg_t;
static int
iter_dependents_cb(zfs_handle_t *zhp, void *arg)
{
iter_dependents_arg_t *ida = arg;
int err = 0;
boolean_t first = ida->first;
ida->first = B_FALSE;
if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
err = zfs_iter_clones(zhp, iter_dependents_cb, ida);
} else if (zhp->zfs_type != ZFS_TYPE_BOOKMARK) {
iter_stack_frame_t isf;
iter_stack_frame_t *f;
/*
* check if there is a cycle by seeing if this fs is already
* on the stack.
*/
for (f = ida->stack; f != NULL; f = f->next) {
if (f->zhp->zfs_dmustats.dds_guid ==
zhp->zfs_dmustats.dds_guid) {
if (ida->allowrecursion) {
zfs_close(zhp);
return (0);
} else {
zfs_error_aux(zhp->zfs_hdl,
dgettext(TEXT_DOMAIN,
"recursive dependency at '%s'"),
zfs_get_name(zhp));
err = zfs_error(zhp->zfs_hdl,
EZFS_RECURSIVE,
dgettext(TEXT_DOMAIN,
"cannot determine dependent "
"datasets"));
zfs_close(zhp);
return (err);
}
}
}
isf.zhp = zhp;
isf.next = ida->stack;
ida->stack = &isf;
err = zfs_iter_filesystems(zhp, iter_dependents_cb, ida);
if (err == 0)
err = zfs_iter_snapshots(zhp, B_FALSE,
iter_dependents_cb, ida, 0, 0);
ida->stack = isf.next;
}
if (!first && err == 0)
err = ida->func(zhp, ida->data);
else
zfs_close(zhp);
return (err);
}
int
zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion,
zfs_iter_f func, void *data)
{
iter_dependents_arg_t ida;
ida.allowrecursion = allowrecursion;
ida.stack = NULL;
ida.func = func;
ida.data = data;
ida.first = B_TRUE;
return (iter_dependents_cb(zfs_handle_dup(zhp), &ida));
}
/*
* Iterate over mounted children of the specified dataset
*/
int
zfs_iter_mounted(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
char mnt_prop[ZFS_MAXPROPLEN];
struct mnttab entry;
zfs_handle_t *mtab_zhp;
size_t namelen = strlen(zhp->zfs_name);
FILE *mnttab;
int err = 0;
if ((mnttab = fopen(MNTTAB, "r")) == NULL)
return (ENOENT);
while (err == 0 && getmntent(mnttab, &entry) == 0) {
/* Ignore non-ZFS entries */
if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
continue;
/* Ignore datasets not within the provided dataset */
if (strncmp(entry.mnt_special, zhp->zfs_name, namelen) != 0 ||
(entry.mnt_special[namelen] != '/' &&
entry.mnt_special[namelen] != '@'))
continue;
if ((mtab_zhp = zfs_open(zhp->zfs_hdl, entry.mnt_special,
ZFS_TYPE_FILESYSTEM)) == NULL)
continue;
/* Ignore legacy mounts as they are user managed */
verify(zfs_prop_get(mtab_zhp, ZFS_PROP_MOUNTPOINT, mnt_prop,
sizeof (mnt_prop), NULL, NULL, 0, B_FALSE) == 0);
if (strcmp(mnt_prop, "legacy") == 0) {
zfs_close(mtab_zhp);
continue;
}
err = func(mtab_zhp, data);
}
fclose(mnttab);
return (err);
}