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Diffstat (limited to 'cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c')
-rw-r--r-- | cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c new file mode 100644 index 0000000..364d92a --- /dev/null +++ b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c @@ -0,0 +1,488 @@ +/* + * 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) 2012 by Delphix. All rights reserved. + */ + +/* + * LibZFS_Core (lzc) is intended to replace most functionality in libzfs. + * It has the following characteristics: + * + * - Thread Safe. libzfs_core is accessible concurrently from multiple + * threads. This is accomplished primarily by avoiding global data + * (e.g. caching). Since it's thread-safe, there is no reason for a + * process to have multiple libzfs "instances". Therefore, we store + * our few pieces of data (e.g. the file descriptor) in global + * variables. The fd is reference-counted so that the libzfs_core + * library can be "initialized" multiple times (e.g. by different + * consumers within the same process). + * + * - Committed Interface. The libzfs_core interface will be committed, + * therefore consumers can compile against it and be confident that + * their code will continue to work on future releases of this code. + * Currently, the interface is Evolving (not Committed), but we intend + * to commit to it once it is more complete and we determine that it + * meets the needs of all consumers. + * + * - Programatic Error Handling. libzfs_core communicates errors with + * defined error numbers, and doesn't print anything to stdout/stderr. + * + * - Thin Layer. libzfs_core is a thin layer, marshaling arguments + * to/from the kernel ioctls. There is generally a 1:1 correspondence + * between libzfs_core functions and ioctls to /dev/zfs. + * + * - Clear Atomicity. Because libzfs_core functions are generally 1:1 + * with kernel ioctls, and kernel ioctls are general atomic, each + * libzfs_core function is atomic. For example, creating multiple + * snapshots with a single call to lzc_snapshot() is atomic -- it + * can't fail with only some of the requested snapshots created, even + * in the event of power loss or system crash. + * + * - Continued libzfs Support. Some higher-level operations (e.g. + * support for "zfs send -R") are too complicated to fit the scope of + * libzfs_core. This functionality will continue to live in libzfs. + * Where appropriate, libzfs will use the underlying atomic operations + * of libzfs_core. For example, libzfs may implement "zfs send -R | + * zfs receive" by using individual "send one snapshot", rename, + * destroy, and "receive one snapshot" operations in libzfs_core. + * /sbin/zfs and /zbin/zpool will link with both libzfs and + * libzfs_core. Other consumers should aim to use only libzfs_core, + * since that will be the supported, stable interface going forwards. + */ + +#define _IN_LIBZFS_CORE_ + +#include <libzfs_core.h> +#include <ctype.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <fcntl.h> +#include <pthread.h> +#include <sys/nvpair.h> +#include <sys/param.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/zfs_ioctl.h> +#include <libzfs_impl.h> + +static int g_fd; +static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER; +static int g_refcount; + +int +libzfs_core_init(void) +{ + (void) pthread_mutex_lock(&g_lock); + if (g_refcount == 0) { + g_fd = open("/dev/zfs", O_RDWR); + if (g_fd < 0) { + (void) pthread_mutex_unlock(&g_lock); + return (errno); + } + } + g_refcount++; + (void) pthread_mutex_unlock(&g_lock); + return (0); +} + +void +libzfs_core_fini(void) +{ + (void) pthread_mutex_lock(&g_lock); + ASSERT3S(g_refcount, >, 0); + g_refcount--; + if (g_refcount == 0) + (void) close(g_fd); + (void) pthread_mutex_unlock(&g_lock); +} + +static int +lzc_ioctl(zfs_ioc_t ioc, const char *name, + nvlist_t *source, nvlist_t **resultp) +{ + zfs_cmd_t zc = { 0 }; + int error = 0; + char *packed; + size_t size; + + ASSERT3S(g_refcount, >, 0); + + (void) strlcpy(zc.zc_name, name, sizeof (zc.zc_name)); + + packed = fnvlist_pack(source, &size); + zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed; + zc.zc_nvlist_src_size = size; + + if (resultp != NULL) { + zc.zc_nvlist_dst_size = MAX(size * 2, 128 * 1024); + zc.zc_nvlist_dst = (uint64_t)(uintptr_t) + malloc(zc.zc_nvlist_dst_size); +#ifdef illumos + if (zc.zc_nvlist_dst == NULL) { +#else + if (zc.zc_nvlist_dst == 0) { +#endif + error = ENOMEM; + goto out; + } + } + + while (ioctl(g_fd, ioc, &zc) != 0) { + if (errno == ENOMEM && resultp != NULL) { + free((void *)(uintptr_t)zc.zc_nvlist_dst); + zc.zc_nvlist_dst_size *= 2; + zc.zc_nvlist_dst = (uint64_t)(uintptr_t) + malloc(zc.zc_nvlist_dst_size); +#ifdef illumos + if (zc.zc_nvlist_dst == NULL) { +#else + if (zc.zc_nvlist_dst == 0) { +#endif + error = ENOMEM; + goto out; + } + } else { + error = errno; + break; + } + } + if (zc.zc_nvlist_dst_filled) { + *resultp = fnvlist_unpack((void *)(uintptr_t)zc.zc_nvlist_dst, + zc.zc_nvlist_dst_size); + } else if (resultp != NULL) { + *resultp = NULL; + } + +out: + fnvlist_pack_free(packed, size); + free((void *)(uintptr_t)zc.zc_nvlist_dst); + return (error); +} + +int +lzc_create(const char *fsname, dmu_objset_type_t type, nvlist_t *props) +{ + int error; + nvlist_t *args = fnvlist_alloc(); + fnvlist_add_int32(args, "type", type); + if (props != NULL) + fnvlist_add_nvlist(args, "props", props); + error = lzc_ioctl(ZFS_IOC_CREATE, fsname, args, NULL); + nvlist_free(args); + return (error); +} + +int +lzc_clone(const char *fsname, const char *origin, + nvlist_t *props) +{ + int error; + nvlist_t *args = fnvlist_alloc(); + fnvlist_add_string(args, "origin", origin); + if (props != NULL) + fnvlist_add_nvlist(args, "props", props); + error = lzc_ioctl(ZFS_IOC_CLONE, fsname, args, NULL); + nvlist_free(args); + return (error); +} + +/* + * Creates snapshots. + * + * The keys in the snaps nvlist are the snapshots to be created. + * They must all be in the same pool. + * + * The props nvlist is properties to set. Currently only user properties + * are supported. { user:prop_name -> string value } + * + * The returned results nvlist will have an entry for each snapshot that failed. + * The value will be the (int32) error code. + * + * The return value will be 0 if all snapshots were created, otherwise it will + * be the errno of a (undetermined) snapshot that failed. + */ +int +lzc_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t **errlist) +{ + nvpair_t *elem; + nvlist_t *args; + int error; + char pool[MAXNAMELEN]; + + *errlist = NULL; + + /* determine the pool name */ + elem = nvlist_next_nvpair(snaps, NULL); + if (elem == NULL) + return (0); + (void) strlcpy(pool, nvpair_name(elem), sizeof (pool)); + pool[strcspn(pool, "/@")] = '\0'; + + args = fnvlist_alloc(); + fnvlist_add_nvlist(args, "snaps", snaps); + if (props != NULL) + fnvlist_add_nvlist(args, "props", props); + + error = lzc_ioctl(ZFS_IOC_SNAPSHOT, pool, args, errlist); + nvlist_free(args); + + return (error); +} + +/* + * Destroys snapshots. + * + * The keys in the snaps nvlist are the snapshots to be destroyed. + * They must all be in the same pool. + * + * Snapshots that do not exist will be silently ignored. + * + * If 'defer' is not set, and a snapshot has user holds or clones, the + * destroy operation will fail and none of the snapshots will be + * destroyed. + * + * If 'defer' is set, and a snapshot has user holds or clones, it will be + * marked for deferred destruction, and will be destroyed when the last hold + * or clone is removed/destroyed. + * + * The return value will be 0 if all snapshots were destroyed (or marked for + * later destruction if 'defer' is set) or didn't exist to begin with. + * + * Otherwise the return value will be the errno of a (undetermined) snapshot + * that failed, no snapshots will be destroyed, and the errlist will have an + * entry for each snapshot that failed. The value in the errlist will be + * the (int32) error code. + */ +int +lzc_destroy_snaps(nvlist_t *snaps, boolean_t defer, nvlist_t **errlist) +{ + nvpair_t *elem; + nvlist_t *args; + int error; + char pool[MAXNAMELEN]; + + /* determine the pool name */ + elem = nvlist_next_nvpair(snaps, NULL); + if (elem == NULL) + return (0); + (void) strlcpy(pool, nvpair_name(elem), sizeof (pool)); + pool[strcspn(pool, "/@")] = '\0'; + + args = fnvlist_alloc(); + fnvlist_add_nvlist(args, "snaps", snaps); + if (defer) + fnvlist_add_boolean(args, "defer"); + + error = lzc_ioctl(ZFS_IOC_DESTROY_SNAPS, pool, args, errlist); + nvlist_free(args); + + return (error); + +} + +int +lzc_snaprange_space(const char *firstsnap, const char *lastsnap, + uint64_t *usedp) +{ + nvlist_t *args; + nvlist_t *result; + int err; + char fs[MAXNAMELEN]; + char *atp; + + /* determine the fs name */ + (void) strlcpy(fs, firstsnap, sizeof (fs)); + atp = strchr(fs, '@'); + if (atp == NULL) + return (EINVAL); + *atp = '\0'; + + args = fnvlist_alloc(); + fnvlist_add_string(args, "firstsnap", firstsnap); + + err = lzc_ioctl(ZFS_IOC_SPACE_SNAPS, lastsnap, args, &result); + nvlist_free(args); + if (err == 0) + *usedp = fnvlist_lookup_uint64(result, "used"); + fnvlist_free(result); + + return (err); +} + +boolean_t +lzc_exists(const char *dataset) +{ + /* + * The objset_stats ioctl is still legacy, so we need to construct our + * own zfs_cmd_t rather than using zfsc_ioctl(). + */ + zfs_cmd_t zc = { 0 }; + + (void) strlcpy(zc.zc_name, dataset, sizeof (zc.zc_name)); + return (ioctl(g_fd, ZFS_IOC_OBJSET_STATS, &zc) == 0); +} + +/* + * If fromsnap is NULL, a full (non-incremental) stream will be sent. + */ +int +lzc_send(const char *snapname, const char *fromsnap, int fd) +{ + nvlist_t *args; + int err; + + args = fnvlist_alloc(); + fnvlist_add_int32(args, "fd", fd); + if (fromsnap != NULL) + fnvlist_add_string(args, "fromsnap", fromsnap); + err = lzc_ioctl(ZFS_IOC_SEND_NEW, snapname, args, NULL); + nvlist_free(args); + return (err); +} + +/* + * If fromsnap is NULL, a full (non-incremental) stream will be estimated. + */ +int +lzc_send_space(const char *snapname, const char *fromsnap, uint64_t *spacep) +{ + nvlist_t *args; + nvlist_t *result; + int err; + + args = fnvlist_alloc(); + if (fromsnap != NULL) + fnvlist_add_string(args, "fromsnap", fromsnap); + err = lzc_ioctl(ZFS_IOC_SEND_SPACE, snapname, args, &result); + nvlist_free(args); + if (err == 0) + *spacep = fnvlist_lookup_uint64(result, "space"); + nvlist_free(result); + return (err); +} + +static int +recv_read(int fd, void *buf, int ilen) +{ + char *cp = buf; + int rv; + int len = ilen; + + do { + rv = read(fd, cp, len); + cp += rv; + len -= rv; + } while (rv > 0); + + if (rv < 0 || len != 0) + return (EIO); + + return (0); +} + +/* + * The simplest receive case: receive from the specified fd, creating the + * specified snapshot. Apply the specified properties a "received" properties + * (which can be overridden by locally-set properties). If the stream is a + * clone, its origin snapshot must be specified by 'origin'. The 'force' + * flag will cause the target filesystem to be rolled back or destroyed if + * necessary to receive. + * + * Return 0 on success or an errno on failure. + * + * Note: this interface does not work on dedup'd streams + * (those with DMU_BACKUP_FEATURE_DEDUP). + */ +int +lzc_receive(const char *snapname, nvlist_t *props, const char *origin, + boolean_t force, int fd) +{ + /* + * The receive ioctl is still legacy, so we need to construct our own + * zfs_cmd_t rather than using zfsc_ioctl(). + */ + zfs_cmd_t zc = { 0 }; + char *atp; + char *packed = NULL; + size_t size; + dmu_replay_record_t drr; + int error; + + ASSERT3S(g_refcount, >, 0); + + /* zc_name is name of containing filesystem */ + (void) strlcpy(zc.zc_name, snapname, sizeof (zc.zc_name)); + atp = strchr(zc.zc_name, '@'); + if (atp == NULL) + return (EINVAL); + *atp = '\0'; + + /* if the fs does not exist, try its parent. */ + if (!lzc_exists(zc.zc_name)) { + char *slashp = strrchr(zc.zc_name, '/'); + if (slashp == NULL) + return (ENOENT); + *slashp = '\0'; + + } + + /* zc_value is full name of the snapshot to create */ + (void) strlcpy(zc.zc_value, snapname, sizeof (zc.zc_value)); + + if (props != NULL) { + /* zc_nvlist_src is props to set */ + packed = fnvlist_pack(props, &size); + zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed; + zc.zc_nvlist_src_size = size; + } + + /* zc_string is name of clone origin (if DRR_FLAG_CLONE) */ + if (origin != NULL) + (void) strlcpy(zc.zc_string, origin, sizeof (zc.zc_string)); + + /* zc_begin_record is non-byteswapped BEGIN record */ + error = recv_read(fd, &drr, sizeof (drr)); + if (error != 0) + goto out; + zc.zc_begin_record = drr.drr_u.drr_begin; + + /* zc_cookie is fd to read from */ + zc.zc_cookie = fd; + + /* zc guid is force flag */ + zc.zc_guid = force; + + /* zc_cleanup_fd is unused */ + zc.zc_cleanup_fd = -1; + + error = ioctl(g_fd, ZFS_IOC_RECV, &zc); + if (error != 0) + error = errno; + +out: + if (packed != NULL) + fnvlist_pack_free(packed, size); + free((void*)(uintptr_t)zc.zc_nvlist_dst); + return (error); +} |