spa_history.c revision da165920f9fa0e493db9dba43b0c3771051409dc
/*
* 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 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/zap.h>
#include <sys/dsl_synctask.h>
#include <sys/dmu_tx.h>
#include <sys/dmu_objset.h>
#include <sys/utsname.h>
#include <sys/cmn_err.h>
#include <sys/sunddi.h>
#ifdef _KERNEL
#include <sys/zone.h>
#endif
/*
* Routines to manage the on-disk history log.
*
* The history log is stored as a dmu object containing
* <packed record length, record nvlist> tuples.
*
* Where "record nvlist" is a nvlist containing uint64_ts and strings, and
* "packed record length" is the packed length of the "record nvlist" stored
* as a little endian uint64_t.
*
* The log is implemented as a ring buffer, though the original creation
* of the pool ('zpool create') is never overwritten.
*
* The history log is tracked as object 'spa_t::spa_history'. The bonus buffer
* of 'spa_history' stores the offsets for logging/retrieving history as
* 'spa_history_phys_t'. 'sh_pool_create_len' is the ending offset in bytes of
* where the 'zpool create' record is stored. This allows us to never
* overwrite the original creation of the pool. 'sh_phys_max_off' is the
* physical ending offset in bytes of the log. This tells you the length of
* the buffer. 'sh_eof' is the logical EOF (in bytes). Whenever a record
* is added, 'sh_eof' is incremented by the the size of the record.
* 'sh_eof' is never decremented. 'sh_bof' is the logical BOF (in bytes).
* This is where the consumer should start reading from after reading in
* the 'zpool create' portion of the log.
*
* 'sh_records_lost' keeps track of how many records have been overwritten
* and permanently lost.
*/
/* convert a logical offset to physical */
static uint64_t
spa_history_log_to_phys(uint64_t log_off, spa_history_phys_t *shpp)
{
uint64_t phys_len;
phys_len = shpp->sh_phys_max_off - shpp->sh_pool_create_len;
return ((log_off - shpp->sh_pool_create_len) % phys_len
+ shpp->sh_pool_create_len);
}
void
spa_history_create_obj(spa_t *spa, dmu_tx_t *tx)
{
dmu_buf_t *dbp;
spa_history_phys_t *shpp;
objset_t *mos = spa->spa_meta_objset;
ASSERT(spa->spa_history == 0);
spa->spa_history = dmu_object_alloc(mos, DMU_OT_SPA_HISTORY,
SPA_MAXBLOCKSIZE, DMU_OT_SPA_HISTORY_OFFSETS,
sizeof (spa_history_phys_t), tx);
VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_HISTORY, sizeof (uint64_t), 1,
&spa->spa_history, tx) == 0);
VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp));
ASSERT(dbp->db_size >= sizeof (spa_history_phys_t));
shpp = dbp->db_data;
dmu_buf_will_dirty(dbp, tx);
/*
* Figure out maximum size of history log. We set it at
* 1% of pool size, with a max of 32MB and min of 128KB.
*/
shpp->sh_phys_max_off = spa_get_dspace(spa) / 100;
shpp->sh_phys_max_off = MIN(shpp->sh_phys_max_off, 32<<20);
shpp->sh_phys_max_off = MAX(shpp->sh_phys_max_off, 128<<10);
dmu_buf_rele(dbp, FTAG);
}
/*
* Change 'sh_bof' to the beginning of the next record.
*/
static int
spa_history_advance_bof(spa_t *spa, spa_history_phys_t *shpp)
{
objset_t *mos = spa->spa_meta_objset;
uint64_t firstread, reclen, phys_bof;
char buf[sizeof (reclen)];
int err;
phys_bof = spa_history_log_to_phys(shpp->sh_bof, shpp);
firstread = MIN(sizeof (reclen), shpp->sh_phys_max_off - phys_bof);
if ((err = dmu_read(mos, spa->spa_history, phys_bof, firstread,
buf)) != 0)
return (err);
if (firstread != sizeof (reclen)) {
if ((err = dmu_read(mos, spa->spa_history,
shpp->sh_pool_create_len, sizeof (reclen) - firstread,
buf + firstread)) != 0)
return (err);
}
reclen = LE_64(*((uint64_t *)buf));
shpp->sh_bof += reclen + sizeof (reclen);
shpp->sh_records_lost++;
return (0);
}
static int
spa_history_write(spa_t *spa, void *buf, uint64_t len, spa_history_phys_t *shpp,
dmu_tx_t *tx)
{
uint64_t firstwrite, phys_eof;
objset_t *mos = spa->spa_meta_objset;
int err;
ASSERT(MUTEX_HELD(&spa->spa_history_lock));
/* see if we need to reset logical BOF */
while (shpp->sh_phys_max_off - shpp->sh_pool_create_len -
(shpp->sh_eof - shpp->sh_bof) <= len) {
if ((err = spa_history_advance_bof(spa, shpp)) != 0) {
return (err);
}
}
phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp);
firstwrite = MIN(len, shpp->sh_phys_max_off - phys_eof);
shpp->sh_eof += len;
dmu_write(mos, spa->spa_history, phys_eof, firstwrite, buf, tx);
len -= firstwrite;
if (len > 0) {
/* write out the rest at the beginning of physical file */
dmu_write(mos, spa->spa_history, shpp->sh_pool_create_len,
len, (char *)buf + firstwrite, tx);
}
return (0);
}
static char *
spa_history_zone()
{
#ifdef _KERNEL
return (curproc->p_zone->zone_name);
#else
return ("global");
#endif
}
/*
* Write out a history event.
*/
static void
spa_history_log_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
{
spa_t *spa = arg1;
history_arg_t *hap = arg2;
const char *history_str = hap->ha_history_str;
objset_t *mos = spa->spa_meta_objset;
dmu_buf_t *dbp;
spa_history_phys_t *shpp;
size_t reclen;
uint64_t le_len;
nvlist_t *nvrecord;
char *record_packed = NULL;
int ret;
/*
* If we have an older pool that doesn't have a command
* history object, create it now.
*/
mutex_enter(&spa->spa_history_lock);
if (!spa->spa_history)
spa_history_create_obj(spa, tx);
mutex_exit(&spa->spa_history_lock);
/*
* Get the offset of where we need to write via the bonus buffer.
* Update the offset when the write completes.
*/
VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp));
shpp = dbp->db_data;
dmu_buf_will_dirty(dbp, tx);
#ifdef ZFS_DEBUG
{
dmu_object_info_t doi;
dmu_object_info_from_db(dbp, &doi);
ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS);
}
#endif
VERIFY(nvlist_alloc(&nvrecord, NV_UNIQUE_NAME, KM_SLEEP) == 0);
VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_TIME,
gethrestime_sec()) == 0);
VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_WHO,
(uint64_t)crgetuid(cr)) == 0);
if (hap->ha_zone[0] != '\0')
VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_ZONE,
hap->ha_zone) == 0);
#ifdef _KERNEL
VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_HOST,
utsname.nodename) == 0);
#endif
if (hap->ha_log_type == LOG_CMD_POOL_CREATE ||
hap->ha_log_type == LOG_CMD_NORMAL) {
VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_CMD,
history_str) == 0);
} else {
VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_INT_EVENT,
hap->ha_event) == 0);
VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_TXG,
tx->tx_txg) == 0);
VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_INT_STR,
history_str) == 0);
}
VERIFY(nvlist_size(nvrecord, &reclen, NV_ENCODE_XDR) == 0);
record_packed = kmem_alloc(reclen, KM_SLEEP);
VERIFY(nvlist_pack(nvrecord, &record_packed, &reclen,
NV_ENCODE_XDR, KM_SLEEP) == 0);
mutex_enter(&spa->spa_history_lock);
if (hap->ha_log_type == LOG_CMD_POOL_CREATE)
VERIFY(shpp->sh_eof == shpp->sh_pool_create_len);
/* write out the packed length as little endian */
le_len = LE_64((uint64_t)reclen);
ret = spa_history_write(spa, &le_len, sizeof (le_len), shpp, tx);
if (!ret)
ret = spa_history_write(spa, record_packed, reclen, shpp, tx);
if (!ret && hap->ha_log_type == LOG_CMD_POOL_CREATE) {
shpp->sh_pool_create_len += sizeof (le_len) + reclen;
shpp->sh_bof = shpp->sh_pool_create_len;
}
mutex_exit(&spa->spa_history_lock);
nvlist_free(nvrecord);
kmem_free(record_packed, reclen);
dmu_buf_rele(dbp, FTAG);
if (hap->ha_log_type == LOG_INTERNAL) {
kmem_free((void*)hap->ha_history_str, HIS_MAX_RECORD_LEN);
kmem_free(hap, sizeof (history_arg_t));
}
}
/*
* Write out a history event.
*/
int
spa_history_log(spa_t *spa, const char *history_str, history_log_type_t what)
{
history_arg_t ha;
ASSERT(what != LOG_INTERNAL);
ha.ha_history_str = history_str;
ha.ha_log_type = what;
(void) strlcpy(ha.ha_zone, spa_history_zone(), sizeof (ha.ha_zone));
return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_history_log_sync,
spa, &ha, 0));
}
/*
* Read out the command history.
*/
int
spa_history_get(spa_t *spa, uint64_t *offp, uint64_t *len, char *buf)
{
objset_t *mos = spa->spa_meta_objset;
dmu_buf_t *dbp;
uint64_t read_len, phys_read_off, phys_eof;
uint64_t leftover = 0;
spa_history_phys_t *shpp;
int err;
/*
* If the command history doesn't exist (older pool),
* that's ok, just return ENOENT.
*/
if (!spa->spa_history)
return (ENOENT);
if ((err = dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp)) != 0)
return (err);
shpp = dbp->db_data;
#ifdef ZFS_DEBUG
{
dmu_object_info_t doi;
dmu_object_info_from_db(dbp, &doi);
ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS);
}
#endif
mutex_enter(&spa->spa_history_lock);
phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp);
if (*offp < shpp->sh_pool_create_len) {
/* read in just the zpool create history */
phys_read_off = *offp;
read_len = MIN(*len, shpp->sh_pool_create_len -
phys_read_off);
} else {
/*
* Need to reset passed in offset to BOF if the passed in
* offset has since been overwritten.
*/
*offp = MAX(*offp, shpp->sh_bof);
phys_read_off = spa_history_log_to_phys(*offp, shpp);
/*
* Read up to the minimum of what the user passed down or
* the EOF (physical or logical). If we hit physical EOF,
* use 'leftover' to read from the physical BOF.
*/
if (phys_read_off <= phys_eof) {
read_len = MIN(*len, phys_eof - phys_read_off);
} else {
read_len = MIN(*len,
shpp->sh_phys_max_off - phys_read_off);
if (phys_read_off + *len > shpp->sh_phys_max_off) {
leftover = MIN(*len - read_len,
phys_eof - shpp->sh_pool_create_len);
}
}
}
/* offset for consumer to use next */
*offp += read_len + leftover;
/* tell the consumer how much you actually read */
*len = read_len + leftover;
if (read_len == 0) {
mutex_exit(&spa->spa_history_lock);
dmu_buf_rele(dbp, FTAG);
return (0);
}
err = dmu_read(mos, spa->spa_history, phys_read_off, read_len, buf);
if (leftover && err == 0) {
err = dmu_read(mos, spa->spa_history, shpp->sh_pool_create_len,
leftover, buf + read_len);
}
mutex_exit(&spa->spa_history_lock);
dmu_buf_rele(dbp, FTAG);
return (err);
}
void
spa_history_internal_log(history_internal_events_t event, spa_t *spa,
dmu_tx_t *tx, cred_t *cr, const char *fmt, ...)
{
history_arg_t *hap;
char *str;
va_list adx;
hap = kmem_alloc(sizeof (history_arg_t), KM_SLEEP);
str = kmem_alloc(HIS_MAX_RECORD_LEN, KM_SLEEP);
va_start(adx, fmt);
(void) vsnprintf(str, HIS_MAX_RECORD_LEN, fmt, adx);
va_end(adx);
hap->ha_log_type = LOG_INTERNAL;
hap->ha_history_str = str;
hap->ha_event = event;
hap->ha_zone[0] = '\0';
if (dmu_tx_is_syncing(tx)) {
spa_history_log_sync(spa, hap, cr, tx);
} else {
dsl_sync_task_do_nowait(spa_get_dsl(spa), NULL,
spa_history_log_sync, spa, hap, 0, tx);
}
/* spa_history_log_sync() will free hap and str */
}