diff options
Diffstat (limited to 'lib/libzfs/libzfs_iter.c')
-rw-r--r-- | lib/libzfs/libzfs_iter.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/lib/libzfs/libzfs_iter.c b/lib/libzfs/libzfs_iter.c new file mode 100644 index 000000000000..7ee326bc6905 --- /dev/null +++ b/lib/libzfs/libzfs_iter.c @@ -0,0 +1,600 @@ +/* + * 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" + +static 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 = zfs_ioctl(zhp->zfs_hdl, 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 (TREE_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); +} |