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Illumos #755: dmu_recv_stream builds incomplete guid_to_ds_map

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An incomplete guid_to_ds_map would cause restore_write_byref() to fail
while receiving a de-duplicated backup stream.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Garrett D`Amore <garrett@nexenta.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References to Illumos issue and patch:
- https://www.illumos.org/issues/755
- https://github.com/illumos/illumos-gate/commit/ec5cf9d53a

Signed-off-by: Gunnar Beutner <gunnar@beutner.name>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #372
This commit is contained in:
Alexander Stetsenko 2011-10-16 08:41:05 +02:00 committed by Brian Behlendorf
parent b385d7da6e
commit 8d35c1499d
2 changed files with 34 additions and 58 deletions
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1
include/sys/dmu.h
View File

@ -721,6 +721,7 @@ typedef struct dmu_recv_cookie {
char *drc_top_ds;
boolean_t drc_newfs;
boolean_t drc_force;
struct avl_tree *drc_guid_to_ds_map;
} dmu_recv_cookie_t;
int dmu_recv_begin(char *tofs, char *tosnap, char *topds, struct drr_begin *,

91
module/zfs/dmu_send.c
View File

@ -21,6 +21,9 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
@ -833,61 +836,6 @@ guid_compare(const void *arg1, const void *arg2)
return (0);
}
/*
* This function is a callback used by dmu_objset_find() (which
* enumerates the object sets) to build an avl tree that maps guids
* to datasets. The resulting table is used when processing DRR_WRITE_BYREF
* send stream records. These records, which are used in dedup'ed
* streams, do not contain data themselves, but refer to a copy
* of the data block that has already been written because it was
* earlier in the stream. That previous copy is identified by the
* guid of the dataset with the referenced data.
*/
int
find_ds_by_guid(const char *name, void *arg)
{
avl_tree_t *guid_map = arg;
dsl_dataset_t *ds, *snapds;
guid_map_entry_t *gmep;
dsl_pool_t *dp;
int err;
uint64_t lastobj, firstobj;
if (dsl_dataset_hold(name, FTAG, &ds) != 0)
return (0);
dp = ds->ds_dir->dd_pool;
rw_enter(&dp->dp_config_rwlock, RW_READER);
firstobj = ds->ds_dir->dd_phys->dd_origin_obj;
lastobj = ds->ds_phys->ds_prev_snap_obj;
while (lastobj != firstobj) {
err = dsl_dataset_hold_obj(dp, lastobj, guid_map, &snapds);
if (err) {
/*
* Skip this snapshot and move on. It's not
* clear why this would ever happen, but the
* remainder of the snapshot streadm can be
* processed.
*/
rw_exit(&dp->dp_config_rwlock);
dsl_dataset_rele(ds, FTAG);
return (0);
}
gmep = kmem_alloc(sizeof (guid_map_entry_t), KM_SLEEP);
gmep->guid = snapds->ds_phys->ds_guid;
gmep->gme_ds = snapds;
avl_add(guid_map, gmep);
lastobj = snapds->ds_phys->ds_prev_snap_obj;
}
rw_exit(&dp->dp_config_rwlock);
dsl_dataset_rele(ds, FTAG);
return (0);
}
static void
free_guid_map_onexit(void *arg)
{
@ -1373,9 +1321,6 @@ dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp,
avl_create(ra.guid_to_ds_map, guid_compare,
sizeof (guid_map_entry_t),
offsetof(guid_map_entry_t, avlnode));
(void) dmu_objset_find(drc->drc_top_ds, find_ds_by_guid,
(void *)ra.guid_to_ds_map,
DS_FIND_CHILDREN);
ra.err = zfs_onexit_add_cb(minor,
free_guid_map_onexit, ra.guid_to_ds_map,
action_handlep);
@ -1387,6 +1332,8 @@ dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp,
if (ra.err)
goto out;
}
drc->drc_guid_to_ds_map = ra.guid_to_ds_map;
}
/*
@ -1524,6 +1471,30 @@ recv_end_sync(void *arg1, void *arg2, dmu_tx_t *tx)
ds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
}
static int
add_ds_to_guidmap(avl_tree_t *guid_map, dsl_dataset_t *ds)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
uint64_t snapobj = ds->ds_phys->ds_prev_snap_obj;
dsl_dataset_t *snapds;
guid_map_entry_t *gmep;
int err;
ASSERT(guid_map != NULL);
rw_enter(&dp->dp_config_rwlock, RW_READER);
err = dsl_dataset_hold_obj(dp, snapobj, guid_map, &snapds);
if (err == 0) {
gmep = kmem_alloc(sizeof (guid_map_entry_t), KM_SLEEP);
gmep->guid = snapds->ds_phys->ds_guid;
gmep->gme_ds = snapds;
avl_add(guid_map, gmep);
}
rw_exit(&dp->dp_config_rwlock);
return (err);
}
static int
dmu_recv_existing_end(dmu_recv_cookie_t *drc)
{
@ -1564,6 +1535,8 @@ dmu_recv_existing_end(dmu_recv_cookie_t *drc)
out:
mutex_exit(&ds->ds_recvlock);
if (err == 0 && drc->drc_guid_to_ds_map != NULL)
(void) add_ds_to_guidmap(drc->drc_guid_to_ds_map, ds);
dsl_dataset_disown(ds, dmu_recv_tag);
(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag, B_FALSE);
return (err);
@ -1593,6 +1566,8 @@ dmu_recv_new_end(dmu_recv_cookie_t *drc)
/* clean up the fs we just recv'd into */
(void) dsl_dataset_destroy(ds, dmu_recv_tag, B_FALSE);
} else {
if (drc->drc_guid_to_ds_map != NULL)
(void) add_ds_to_guidmap(drc->drc_guid_to_ds_map, ds);
/* release the hold from dmu_recv_begin */
dsl_dataset_disown(ds, dmu_recv_tag);
}