common/zfs/zfeature_common.c

	zfeature_common.c revision c3d26abc9ee97b4f60233556aadeb57e0bd30bb9
/*
 * 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) 2011, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
 * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 */

#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <errno.h>
#include <string.h>
#endif
#include <sys/debug.h>
#include <sys/fs/zfs.h>
#include <sys/inttypes.h>
#include <sys/types.h>
#include "zfeature_common.h"

/*
 * Set to disable all feature checks while opening pools, allowing pools with
 * unsupported features to be opened. Set for testing only.
 */
boolean_t zfeature_checks_disable = B_FALSE;

zfeature_info_t spa_feature_table[SPA_FEATURES];

/*
 * Valid characters for feature guids. This list is mainly for aesthetic
 * purposes and could be expanded in the future. There are different allowed
 * characters in the guids reverse dns portion (before the colon) and its
 * short name (after the colon).
 */
static int
valid_char(char c, boolean_t after_colon)
{
    return ((c >= 'a' && c <= 'z') ||
        (c >= '0' && c <= '9') ||
        (after_colon && c == '_') ||
        (!after_colon && (c == '.' || c == '-')));
}

/*
 * Every feature guid must contain exactly one colon which separates a reverse
 * dns organization name from the feature's "short" name (e.g.
 * "com.company:feature_name").
 */
boolean_t
zfeature_is_valid_guid(const char *name)
{
    int i;
    boolean_t has_colon = B_FALSE;

    i = 0;
    while (name[i] != '\0') {
        char c = name[i++];
        if (c == ':') {
            if (has_colon)
                return (B_FALSE);
            has_colon = B_TRUE;
            continue;
        }
        if (!valid_char(c, has_colon))
            return (B_FALSE);
    }

    return (has_colon);
}

boolean_t
zfeature_is_supported(const char *guid)
{
    if (zfeature_checks_disable)
        return (B_TRUE);

    for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
        zfeature_info_t *feature = &spa_feature_table[i];
        if (strcmp(guid, feature->fi_guid) == 0)
            return (B_TRUE);
    }
    return (B_FALSE);
}

int
zfeature_lookup_name(const char *name, spa_feature_t *res)
{
    for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
        zfeature_info_t *feature = &spa_feature_table[i];
        if (strcmp(name, feature->fi_uname) == 0) {
            if (res != NULL)
                *res = i;
            return (0);
        }
    }

    return (ENOENT);
}

boolean_t
zfeature_depends_on(spa_feature_t fid, spa_feature_t check)
{
    zfeature_info_t *feature = &spa_feature_table[fid];

    for (int i = 0; feature->fi_depends[i] != SPA_FEATURE_NONE; i++) {
        if (feature->fi_depends[i] == check)
            return (B_TRUE);
    }
    return (B_FALSE);
}

static void
zfeature_register(spa_feature_t fid, const char *guid, const char *name,
    const char *desc, zfeature_flags_t flags, const spa_feature_t *deps)
{
    zfeature_info_t *feature = &spa_feature_table[fid];
    static spa_feature_t nodeps[] = { SPA_FEATURE_NONE };

    ASSERT(name != NULL);
    ASSERT(desc != NULL);
    ASSERT((flags & ZFEATURE_FLAG_READONLY_COMPAT) == 0 ||
        (flags & ZFEATURE_FLAG_MOS) == 0);
    ASSERT3U(fid, <, SPA_FEATURES);
    ASSERT(zfeature_is_valid_guid(guid));

    if (deps == NULL)
        deps = nodeps;

    feature->fi_feature = fid;
    feature->fi_guid = guid;
    feature->fi_uname = name;
    feature->fi_desc = desc;
    feature->fi_flags = flags;
    feature->fi_depends = deps;
}

void
zpool_feature_init(void)
{
    zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
        "com.delphix:async_destroy", "async_destroy",
        "Destroy filesystems asynchronously.",
        ZFEATURE_FLAG_READONLY_COMPAT, NULL);

    zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
        "com.delphix:empty_bpobj", "empty_bpobj",
        "Snapshots use less space.",
        ZFEATURE_FLAG_READONLY_COMPAT, NULL);

    zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
        "org.illumos:lz4_compress", "lz4_compress",
        "LZ4 compression algorithm support.",
        ZFEATURE_FLAG_ACTIVATE_ON_ENABLE, NULL);

    zfeature_register(SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
        "com.joyent:multi_vdev_crash_dump", "multi_vdev_crash_dump",
        "Crash dumps to multiple vdev pools.",
        0, NULL);

    zfeature_register(SPA_FEATURE_SPACEMAP_HISTOGRAM,
        "com.delphix:spacemap_histogram", "spacemap_histogram",
        "Spacemaps maintain space histograms.",
        ZFEATURE_FLAG_READONLY_COMPAT, NULL);

    zfeature_register(SPA_FEATURE_ENABLED_TXG,
        "com.delphix:enabled_txg", "enabled_txg",
        "Record txg at which a feature is enabled",
        ZFEATURE_FLAG_READONLY_COMPAT, NULL);

    static spa_feature_t hole_birth_deps[] = { SPA_FEATURE_ENABLED_TXG,
        SPA_FEATURE_NONE };
    zfeature_register(SPA_FEATURE_HOLE_BIRTH,
        "com.delphix:hole_birth", "hole_birth",
        "Retain hole birth txg for more precise zfs send",
        ZFEATURE_FLAG_MOS | ZFEATURE_FLAG_ACTIVATE_ON_ENABLE,
        hole_birth_deps);

    zfeature_register(SPA_FEATURE_EXTENSIBLE_DATASET,
        "com.delphix:extensible_dataset", "extensible_dataset",
        "Enhanced dataset functionality, used by other features.",
        0, NULL);

    static const spa_feature_t bookmarks_deps[] = {
        SPA_FEATURE_EXTENSIBLE_DATASET,
        SPA_FEATURE_NONE
    };
    zfeature_register(SPA_FEATURE_BOOKMARKS,
        "com.delphix:bookmarks", "bookmarks",
        "\"zfs bookmark\" command",
        ZFEATURE_FLAG_READONLY_COMPAT, bookmarks_deps);

    static const spa_feature_t filesystem_limits_deps[] = {
        SPA_FEATURE_EXTENSIBLE_DATASET,
        SPA_FEATURE_NONE
    };
    zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
        "com.joyent:filesystem_limits", "filesystem_limits",
        "Filesystem and snapshot limits.",
        ZFEATURE_FLAG_READONLY_COMPAT, filesystem_limits_deps);

    zfeature_register(SPA_FEATURE_EMBEDDED_DATA,
        "com.delphix:embedded_data", "embedded_data",
        "Blocks which compress very well use even less space.",
        ZFEATURE_FLAG_MOS | ZFEATURE_FLAG_ACTIVATE_ON_ENABLE,
        NULL);

    static const spa_feature_t large_blocks_deps[] = {
        SPA_FEATURE_EXTENSIBLE_DATASET,
        SPA_FEATURE_NONE
    };
    zfeature_register(SPA_FEATURE_LARGE_BLOCKS,
        "org.open-zfs:large_blocks", "large_blocks",
        "Support for blocks larger than 128KB.",
        ZFEATURE_FLAG_PER_DATASET, large_blocks_deps);

    zfeature_register(SPA_FEATURE_SHA512,
        "org.illumos:sha512", "sha512",
        "SHA-512/256 hash algorithm.",
        ZFEATURE_FLAG_PER_DATASET, NULL);
    zfeature_register(SPA_FEATURE_SKEIN,
        "org.illumos:skein", "skein",
        "Skein hash algorithm.",
        ZFEATURE_FLAG_PER_DATASET, NULL);
    zfeature_register(SPA_FEATURE_EDONR,
        "org.illumos:edonr", "edonr",
        "Edon-R hash algorithm.",
        ZFEATURE_FLAG_PER_DATASET, NULL);
}