cmd/zinject/translate.c

	translate.c revision feef89cf5f5fee792c1a396bb0e48070935cf65a
/*
 * 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.
 */

#include <libzfs.h>

#include <sys/zfs_context.h>

#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/file.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/param.h>
#include <sys/stat.h>

#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dnode.h>
#include <sys/vdev_impl.h>

#include <sys/mkdev.h>

#include "zinject.h"

extern void kernel_init(int);
extern void kernel_fini(void);

static int debug;

static void
ziprintf(const char *fmt, ...)
{
    va_list ap;

    if (!debug)
        return;

    va_start(ap, fmt);
    (void) vprintf(fmt, ap);
    va_end(ap);
}

/*
 * Given a full path to a file, translate into a dataset name and a relative
 * path within the dataset.  'dataset' must be at least MAXNAMELEN characters,
 * and 'relpath' must be at least MAXPATHLEN characters.  We also pass a stat64
 * buffer, which we need later to get the object ID.
 */
static int
parse_pathname(const char *fullpath, char *dataset, char *relpath,
    struct stat64 *statbuf)
{
    struct extmnttab mp;
    FILE *fp;
    int match;
    const char *rel;

    if (fullpath[0] != '/') {
        (void) fprintf(stderr, "invalid object '%s': must be full "
            "path\n", fullpath);
        usage();
        return (-1);
    }

    if (strlen(fullpath) >= MAXPATHLEN) {
        (void) fprintf(stderr, "invalid object; pathname too long\n");
        return (-1);
    }

    if (stat64(fullpath, statbuf) != 0) {
        (void) fprintf(stderr, "cannot open '%s': %s\n",
            fullpath, strerror(errno));
        return (-1);
    }

    if ((fp = fopen(MNTTAB, "r")) == NULL) {
        (void) fprintf(stderr, "cannot open /etc/mnttab\n");
        return (-1);
    }

    match = 0;
    while (getextmntent(fp, &mp, sizeof (mp)) == 0) {
        if (makedev(mp.mnt_major, mp.mnt_minor) == statbuf->st_dev) {
            match = 1;
            break;
        }
    }

    if (!match) {
        (void) fprintf(stderr, "cannot find mountpoint for '%s'\n",
            fullpath);
        return (-1);
    }

    if (strcmp(mp.mnt_fstype, MNTTYPE_ZFS) != 0) {
        (void) fprintf(stderr, "invalid path '%s': not a ZFS "
            "filesystem\n", fullpath);
        return (-1);
    }

    if (strncmp(fullpath, mp.mnt_mountp, strlen(mp.mnt_mountp)) != 0) {
        (void) fprintf(stderr, "invalid path '%s': mountpoint "
            "doesn't match path\n", fullpath);
        return (-1);
    }

    (void) strcpy(dataset, mp.mnt_special);

    rel = fullpath + strlen(mp.mnt_mountp);
    if (rel[0] == '/')
        rel++;
    (void) strcpy(relpath, rel);

    return (0);
}

/*
 * Convert from a (dataset, path) pair into a (objset, object) pair.  Note that
 * we grab the object number from the inode number, since looking this up via
 * libzpool is a real pain.
 */
/* ARGSUSED */
static int
object_from_path(const char *dataset, const char *path, struct stat64 *statbuf,
    zinject_record_t *record)
{
    objset_t *os;
    int err;

    /*
     * Before doing any libzpool operations, call sync() to ensure that the
     * on-disk state is consistent with the in-core state.
     */
    sync();

    err = dmu_objset_own(dataset, DMU_OST_ZFS, B_TRUE, FTAG, &os);
    if (err != 0) {
        (void) fprintf(stderr, "cannot open dataset '%s': %s\n",
            dataset, strerror(err));
        return (-1);
    }

    record->zi_objset = dmu_objset_id(os);
    record->zi_object = statbuf->st_ino;

    dmu_objset_disown(os, FTAG);

    return (0);
}

/*
 * Calculate the real range based on the type, level, and range given.
 */
static int
calculate_range(const char *dataset, err_type_t type, int level, char *range,
    zinject_record_t *record)
{
    objset_t *os = NULL;
    dnode_t *dn = NULL;
    int err;
    int ret = -1;

    /*
     * Determine the numeric range from the string.
     */
    if (range == NULL) {
        /*
         * If range is unspecified, set the range to [0,-1], which
         * indicates that the whole object should be treated as an
         * error.
         */
        record->zi_start = 0;
        record->zi_end = -1ULL;
    } else {
        char *end;

        /* XXX add support for suffixes */
        record->zi_start = strtoull(range, &end, 10);


        if (*end == '\0')
            record->zi_end = record->zi_start + 1;
        else if (*end == ',')
            record->zi_end = strtoull(end + 1, &end, 10);

        if (*end != '\0') {
            (void) fprintf(stderr, "invalid range '%s': must be "
                "a numeric range of the form 'start[,end]'\n",
                range);
            goto out;
        }
    }

    switch (type) {
    case TYPE_DATA:
        break;

    case TYPE_DNODE:
        /*
         * If this is a request to inject faults into the dnode, then we
         * must translate the current (objset,object) pair into an
         * offset within the metadnode for the objset.  Specifying any
         * kind of range with type 'dnode' is illegal.
         */
        if (range != NULL) {
            (void) fprintf(stderr, "range cannot be specified when "
                "type is 'dnode'\n");
            goto out;
        }

        record->zi_start = record->zi_object * sizeof (dnode_phys_t);
        record->zi_end = record->zi_start + sizeof (dnode_phys_t);
        record->zi_object = 0;
        break;
    }

    /*
     * Get the dnode associated with object, so we can calculate the block
     * size.
     */
    if ((err = dmu_objset_own(dataset, DMU_OST_ANY,
        B_TRUE, FTAG, &os)) != 0) {
        (void) fprintf(stderr, "cannot open dataset '%s': %s\n",
            dataset, strerror(err));
        goto out;
    }

    if (record->zi_object == 0) {
        dn = os->os_meta_dnode;
    } else {
        err = dnode_hold(os, record->zi_object, FTAG, &dn);
        if (err != 0) {
            (void) fprintf(stderr, "failed to hold dnode "
                "for object %llu\n",
                (u_longlong_t)record->zi_object);
            goto out;
        }
    }


    ziprintf("data shift: %d\n", (int)dn->dn_datablkshift);
    ziprintf(" ind shift: %d\n", (int)dn->dn_indblkshift);

    /*
     * Translate range into block IDs.
     */
    if (record->zi_start != 0 || record->zi_end != -1ULL) {
        record->zi_start >>= dn->dn_datablkshift;
        record->zi_end >>= dn->dn_datablkshift;
    }

    /*
     * Check level, and then translate level 0 blkids into ranges
     * appropriate for level of indirection.
     */
    record->zi_level = level;
    if (level > 0) {
        ziprintf("level 0 blkid range: [%llu, %llu]\n",
            record->zi_start, record->zi_end);

        if (level >= dn->dn_nlevels) {
            (void) fprintf(stderr, "level %d exceeds max level "
                "of object (%d)\n", level, dn->dn_nlevels - 1);
            goto out;
        }

        if (record->zi_start != 0 || record->zi_end != 0) {
            int shift = dn->dn_indblkshift - SPA_BLKPTRSHIFT;

            for (; level > 0; level--) {
                record->zi_start >>= shift;
                record->zi_end >>= shift;
            }
        }
    }

    ret = 0;
out:
    if (dn) {
        if (dn != os->os_meta_dnode)
            dnode_rele(dn, FTAG);
    }
    if (os)
        dmu_objset_disown(os, FTAG);

    return (ret);
}

int
translate_record(err_type_t type, const char *object, const char *range,
    int level, zinject_record_t *record, char *poolname, char *dataset)
{
    char path[MAXPATHLEN];
    char *slash;
    struct stat64 statbuf;
    int ret = -1;

    kernel_init(FREAD);

    debug = (getenv("ZINJECT_DEBUG") != NULL);

    ziprintf("translating: %s\n", object);

    if (MOS_TYPE(type)) {
        /*
         * MOS objects are treated specially.
         */
        switch (type) {
        case TYPE_MOS:
            record->zi_type = 0;
            break;
        case TYPE_MOSDIR:
            record->zi_type = DMU_OT_OBJECT_DIRECTORY;
            break;
        case TYPE_METASLAB:
            record->zi_type = DMU_OT_OBJECT_ARRAY;
            break;
        case TYPE_CONFIG:
            record->zi_type = DMU_OT_PACKED_NVLIST;
            break;
        case TYPE_BPLIST:
            record->zi_type = DMU_OT_BPLIST;
            break;
        case TYPE_SPACEMAP:
            record->zi_type = DMU_OT_SPACE_MAP;
            break;
        case TYPE_ERRLOG:
            record->zi_type = DMU_OT_ERROR_LOG;
            break;
        }

        dataset[0] = '\0';
        (void) strcpy(poolname, object);
        return (0);
    }

    /*
     * Convert a full path into a (dataset, file) pair.
     */
    if (parse_pathname(object, dataset, path, &statbuf) != 0)
        goto err;

    ziprintf("   dataset: %s\n", dataset);
    ziprintf("      path: %s\n", path);

    /*
     * Convert (dataset, file) into (objset, object)
     */
    if (object_from_path(dataset, path, &statbuf, record) != 0)
        goto err;

    ziprintf("raw objset: %llu\n", record->zi_objset);
    ziprintf("raw object: %llu\n", record->zi_object);

    /*
     * For the given object, calculate the real (type, level, range)
     */
    if (calculate_range(dataset, type, level, (char *)range, record) != 0)
        goto err;

    ziprintf("    objset: %llu\n", record->zi_objset);
    ziprintf("    object: %llu\n", record->zi_object);
    if (record->zi_start == 0 &&
        record->zi_end == -1ULL)
        ziprintf("     range: all\n");
    else
        ziprintf("     range: [%llu, %llu]\n", record->zi_start,
            record->zi_end);

    /*
     * Copy the pool name
     */
    (void) strcpy(poolname, dataset);
    if ((slash = strchr(poolname, '/')) != NULL)
        *slash = '\0';

    ret = 0;

err:
    kernel_fini();
    return (ret);
}

int
translate_raw(const char *str, zinject_record_t *record)
{
    /*
     * A raw bookmark of the form objset:object:level:blkid, where each
     * number is a hexidecimal value.
     */
    if (sscanf(str, "%llx:%llx:%x:%llx", (u_longlong_t *)&record->zi_objset,
        (u_longlong_t *)&record->zi_object, &record->zi_level,
        (u_longlong_t *)&record->zi_start) != 4) {
        (void) fprintf(stderr, "bad raw spec '%s': must be of the form "
            "'objset:object:level:blkid'\n", str);
        return (-1);
    }

    record->zi_end = record->zi_start;

    return (0);
}

int
translate_device(const char *pool, const char *device, err_type_t label_type,
    zinject_record_t *record)
{
    char *end;
    zpool_handle_t *zhp;
    nvlist_t *tgt;
    boolean_t isspare, iscache;

    /*
     * Given a device name or GUID, create an appropriate injection record
     * with zi_guid set.
     */
    if ((zhp = zpool_open(g_zfs, pool)) == NULL)
        return (-1);

    record->zi_guid = strtoull(device, &end, 16);
    if (record->zi_guid == 0 || *end != '\0') {
        tgt = zpool_find_vdev(zhp, device, &isspare, &iscache, NULL);

        if (tgt == NULL) {
            (void) fprintf(stderr, "cannot find device '%s' in "
                "pool '%s'\n", device, pool);
            return (-1);
        }

        verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID,
            &record->zi_guid) == 0);
    }

    switch (label_type) {
    case TYPE_LABEL_UBERBLOCK:
        record->zi_start = offsetof(vdev_label_t, vl_uberblock[0]);
        record->zi_end = record->zi_start + VDEV_UBERBLOCK_RING - 1;
        break;
    case TYPE_LABEL_NVLIST:
        record->zi_start = offsetof(vdev_label_t, vl_vdev_phys);
        record->zi_end = record->zi_start + VDEV_PHYS_SIZE - 1;
        break;
    }
    return (0);
}