freebsd-dev/module/zfs/dmu_traverse.c
Brian Behlendorf 47050a88ac Fix stack traverse_impl()
Stack use reduced from 560 bytes to 128 bytes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-08-31 08:38:49 -07:00

491 lines
12 KiB
C

/*
* 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.
*/
#include <sys/zfs_context.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_pool.h>
#include <sys/dnode.h>
#include <sys/spa.h>
#include <sys/zio.h>
#include <sys/dmu_impl.h>
#include <sys/sa.h>
#include <sys/sa_impl.h>
#include <sys/callb.h>
int zfs_pd_blks_max = 100;
typedef struct prefetch_data {
kmutex_t pd_mtx;
kcondvar_t pd_cv;
int pd_blks_max;
int pd_blks_fetched;
int pd_flags;
boolean_t pd_cancel;
boolean_t pd_exited;
} prefetch_data_t;
typedef struct traverse_data {
spa_t *td_spa;
uint64_t td_objset;
blkptr_t *td_rootbp;
uint64_t td_min_txg;
int td_flags;
prefetch_data_t *td_pfd;
blkptr_cb_t *td_func;
void *td_arg;
} traverse_data_t;
static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *buf, uint64_t objset, uint64_t object);
static int
traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
{
traverse_data_t *td = arg;
zbookmark_t zb;
if (bp->blk_birth == 0)
return (0);
if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa))
return (0);
SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
(void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL, td->td_arg);
return (0);
}
static int
traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
{
traverse_data_t *td = arg;
if (lrc->lrc_txtype == TX_WRITE) {
lr_write_t *lr = (lr_write_t *)lrc;
blkptr_t *bp = &lr->lr_blkptr;
zbookmark_t zb;
if (bp->blk_birth == 0)
return (0);
if (claim_txg == 0 || bp->blk_birth < claim_txg)
return (0);
SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
(void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL,
td->td_arg);
}
return (0);
}
static void
traverse_zil(traverse_data_t *td, zil_header_t *zh)
{
uint64_t claim_txg = zh->zh_claim_txg;
zilog_t *zilog;
/*
* We only want to visit blocks that have been claimed but not yet
* replayed; plus, in read-only mode, blocks that are already stable.
*/
if (claim_txg == 0 && spa_writeable(td->td_spa))
return;
zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
(void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
claim_txg);
zil_free(zilog);
}
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
{
zbookmark_t czb;
int err = 0, lasterr = 0;
arc_buf_t *buf = NULL;
prefetch_data_t *pd = td->td_pfd;
boolean_t hard = td->td_flags & TRAVERSE_HARD;
if (bp->blk_birth == 0) {
err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp,
td->td_arg);
return (err);
}
if (bp->blk_birth <= td->td_min_txg)
return (0);
if (pd && !pd->pd_exited &&
((pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) {
mutex_enter(&pd->pd_mtx);
ASSERT(pd->pd_blks_fetched >= 0);
while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
cv_wait(&pd->pd_cv, &pd->pd_mtx);
pd->pd_blks_fetched--;
cv_broadcast(&pd->pd_cv);
mutex_exit(&pd->pd_mtx);
}
if (td->td_flags & TRAVERSE_PRE) {
err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
td->td_arg);
if (err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (err)
return (err);
}
if (BP_GET_LEVEL(bp) > 0) {
uint32_t flags = ARC_WAIT;
int i;
blkptr_t *cbp;
int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
err = dsl_read(NULL, td->td_spa, bp, pbuf,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
/* recursively visitbp() blocks below this */
cbp = buf->b_data;
for (i = 0; i < epb; i++, cbp++) {
SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
zb->zb_level - 1,
zb->zb_blkid * epb + i);
err = traverse_visitbp(td, dnp, buf, cbp, &czb);
if (err) {
if (!hard)
break;
lasterr = err;
}
}
} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
uint32_t flags = ARC_WAIT;
int i;
int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
err = dsl_read(NULL, td->td_spa, bp, pbuf,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
/* recursively visitbp() blocks below this */
dnp = buf->b_data;
for (i = 0; i < epb; i++, dnp++) {
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
zb->zb_blkid * epb + i);
if (err) {
if (!hard)
break;
lasterr = err;
}
}
} else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
uint32_t flags = ARC_WAIT;
objset_phys_t *osp;
dnode_phys_t *dnp;
err = dsl_read_nolock(NULL, td->td_spa, bp,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
osp = buf->b_data;
dnp = &osp->os_meta_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_META_DNODE_OBJECT);
if (err && hard) {
lasterr = err;
err = 0;
}
if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
dnp = &osp->os_userused_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_USERUSED_OBJECT);
}
if (err && hard) {
lasterr = err;
err = 0;
}
if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
dnp = &osp->os_groupused_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_GROUPUSED_OBJECT);
}
}
if (buf)
(void) arc_buf_remove_ref(buf, &buf);
if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) {
err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
td->td_arg);
}
return (err != 0 ? err : lasterr);
}
static int
traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *buf, uint64_t objset, uint64_t object)
{
int j, err = 0, lasterr = 0;
zbookmark_t czb;
boolean_t hard = (td->td_flags & TRAVERSE_HARD);
for (j = 0; j < dnp->dn_nblkptr; j++) {
SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
err = traverse_visitbp(td, dnp, buf,
(blkptr_t *)&dnp->dn_blkptr[j], &czb);
if (err) {
if (!hard)
break;
lasterr = err;
}
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
SET_BOOKMARK(&czb, objset,
object, 0, DMU_SPILL_BLKID);
err = traverse_visitbp(td, dnp, buf,
(blkptr_t *)&dnp->dn_spill, &czb);
if (err) {
if (!hard)
return (err);
lasterr = err;
}
}
return (err != 0 ? err : lasterr);
}
/* ARGSUSED */
static int
traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp,
void *arg)
{
prefetch_data_t *pfd = arg;
uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
ASSERT(pfd->pd_blks_fetched >= 0);
if (pfd->pd_cancel)
return (EINTR);
if (bp == NULL || !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0) ||
BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG)
return (0);
mutex_enter(&pfd->pd_mtx);
while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max)
cv_wait(&pfd->pd_cv, &pfd->pd_mtx);
pfd->pd_blks_fetched++;
cv_broadcast(&pfd->pd_cv);
mutex_exit(&pfd->pd_mtx);
(void) dsl_read(NULL, spa, bp, pbuf, NULL, NULL,
ZIO_PRIORITY_ASYNC_READ,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
&aflags, zb);
return (0);
}
static void
traverse_prefetch_thread(void *arg)
{
traverse_data_t *td_main = arg;
traverse_data_t td = *td_main;
zbookmark_t czb;
td.td_func = traverse_prefetcher;
td.td_arg = td_main->td_pfd;
td.td_pfd = NULL;
SET_BOOKMARK(&czb, td.td_objset,
ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
(void) traverse_visitbp(&td, NULL, NULL, td.td_rootbp, &czb);
mutex_enter(&td_main->td_pfd->pd_mtx);
td_main->td_pfd->pd_exited = B_TRUE;
cv_broadcast(&td_main->td_pfd->pd_cv);
mutex_exit(&td_main->td_pfd->pd_mtx);
}
/*
* NB: dataset must not be changing on-disk (eg, is a snapshot or we are
* in syncing context).
*/
static int
traverse_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *rootbp,
uint64_t txg_start, int flags, blkptr_cb_t func, void *arg)
{
traverse_data_t *td;
prefetch_data_t *pd;
zbookmark_t *czb;
int err;
td = kmem_alloc(sizeof(traverse_data_t), KM_SLEEP);
pd = kmem_zalloc(sizeof(prefetch_data_t), KM_SLEEP);
czb = kmem_alloc(sizeof(zbookmark_t), KM_SLEEP);
td->td_spa = spa;
td->td_objset = ds ? ds->ds_object : 0;
td->td_rootbp = rootbp;
td->td_min_txg = txg_start;
td->td_func = func;
td->td_arg = arg;
td->td_pfd = pd;
td->td_flags = flags;
pd->pd_blks_max = zfs_pd_blks_max;
pd->pd_flags = flags;
mutex_init(&pd->pd_mtx, NULL, MUTEX_DEFAULT, NULL);
cv_init(&pd->pd_cv, NULL, CV_DEFAULT, NULL);
/* See comment on ZIL traversal in dsl_scan_visitds. */
if (ds != NULL && !dsl_dataset_is_snapshot(ds)) {
objset_t *os;
err = dmu_objset_from_ds(ds, &os);
if (err)
return (err);
traverse_zil(td, &os->os_zil_header);
}
if (!(flags & TRAVERSE_PREFETCH) ||
0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
td, TQ_NOQUEUE))
pd->pd_exited = B_TRUE;
SET_BOOKMARK(czb, td->td_objset,
ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
err = traverse_visitbp(td, NULL, NULL, rootbp, czb);
mutex_enter(&pd->pd_mtx);
pd->pd_cancel = B_TRUE;
cv_broadcast(&pd->pd_cv);
while (!pd->pd_exited)
cv_wait(&pd->pd_cv, &pd->pd_mtx);
mutex_exit(&pd->pd_mtx);
mutex_destroy(&pd->pd_mtx);
cv_destroy(&pd->pd_cv);
kmem_free(czb, sizeof(zbookmark_t));
kmem_free(pd, sizeof(struct prefetch_data));
kmem_free(td, sizeof(struct traverse_data));
return (err);
}
/*
* NB: dataset must not be changing on-disk (eg, is a snapshot or we are
* in syncing context).
*/
int
traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags,
blkptr_cb_t func, void *arg)
{
return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds,
&ds->ds_phys->ds_bp, txg_start, flags, func, arg));
}
/*
* NB: pool must not be changing on-disk (eg, from zdb or sync context).
*/
int
traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
blkptr_cb_t func, void *arg)
{
int err, lasterr = 0;
uint64_t obj;
dsl_pool_t *dp = spa_get_dsl(spa);
objset_t *mos = dp->dp_meta_objset;
boolean_t hard = (flags & TRAVERSE_HARD);
/* visit the MOS */
err = traverse_impl(spa, NULL, spa_get_rootblkptr(spa),
txg_start, flags, func, arg);
if (err)
return (err);
/* visit each dataset */
for (obj = 1; err == 0 || (err != ESRCH && hard);
err = dmu_object_next(mos, &obj, FALSE, txg_start)) {
dmu_object_info_t doi;
err = dmu_object_info(mos, obj, &doi);
if (err) {
if (!hard)
return (err);
lasterr = err;
continue;
}
if (doi.doi_type == DMU_OT_DSL_DATASET) {
dsl_dataset_t *ds;
uint64_t txg = txg_start;
rw_enter(&dp->dp_config_rwlock, RW_READER);
err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
rw_exit(&dp->dp_config_rwlock);
if (err) {
if (!hard)
return (err);
lasterr = err;
continue;
}
if (ds->ds_phys->ds_prev_snap_txg > txg)
txg = ds->ds_phys->ds_prev_snap_txg;
err = traverse_dataset(ds, txg, flags, func, arg);
dsl_dataset_rele(ds, FTAG);
if (err) {
if (!hard)
return (err);
lasterr = err;
}
}
}
if (err == ESRCH)
err = 0;
return (err != 0 ? err : lasterr);
}