Long hold the dataset during upgrade

If the receive or rollback is performed while filesystem is upgrading
the objset may be evicted in `dsl_dataset_clone_swap_sync_impl`. This
will lead to NULL pointer dereference when upgrade tries to access
evicted objset.

This commit adds long hold of dataset during whole upgrade process.
The receive and rollback will return an EBUSY error until the
upgrade is not finished.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arkadiusz Bubała <arkadiusz.bubala@open-e.com>
Closes #5295
Closes #6837
This commit is contained in:
Arkadiusz Bubała 2017-11-10 22:37:10 +01:00 committed by Tony Hutter
parent d7881a6dca
commit a5c8119eba
3 changed files with 24 additions and 6 deletions

View File

@ -28,6 +28,7 @@
* Copyright (c) 2015, STRATO AG, Inc. All rights reserved.
* Copyright (c) 2016 Actifio, Inc. All rights reserved.
* Copyright 2017 Nexenta Systems, Inc.
* Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
*/
/* Portions Copyright 2010 Robert Milkowski */
@ -78,6 +79,8 @@ int dmu_find_threads = 0;
*/
int dmu_rescan_dnode_threshold = 1 << DN_MAX_INDBLKSHIFT;
static char *upgrade_tag = "upgrade_tag";
static void dmu_objset_find_dp_cb(void *arg);
static void dmu_objset_upgrade(objset_t *os, dmu_objset_upgrade_cb_t cb);
@ -1157,6 +1160,7 @@ dmu_objset_upgrade_task_cb(void *data)
os->os_upgrade_exit = B_TRUE;
os->os_upgrade_id = 0;
mutex_exit(&os->os_upgrade_lock);
dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
}
static void
@ -1165,6 +1169,9 @@ dmu_objset_upgrade(objset_t *os, dmu_objset_upgrade_cb_t cb)
if (os->os_upgrade_id != 0)
return;
ASSERT(dsl_pool_config_held(dmu_objset_pool(os)));
dsl_dataset_long_hold(dmu_objset_ds(os), upgrade_tag);
mutex_enter(&os->os_upgrade_lock);
if (os->os_upgrade_id == 0 && os->os_upgrade_status == 0) {
os->os_upgrade_exit = B_FALSE;
@ -1172,9 +1179,11 @@ dmu_objset_upgrade(objset_t *os, dmu_objset_upgrade_cb_t cb)
os->os_upgrade_id = taskq_dispatch(
os->os_spa->spa_upgrade_taskq,
dmu_objset_upgrade_task_cb, os, TQ_SLEEP);
if (os->os_upgrade_id == TASKQID_INVALID)
if (os->os_upgrade_id == TASKQID_INVALID) {
dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
os->os_upgrade_status = ENOMEM;
}
}
mutex_exit(&os->os_upgrade_lock);
}
@ -1189,7 +1198,10 @@ dmu_objset_upgrade_stop(objset_t *os)
os->os_upgrade_id = 0;
mutex_exit(&os->os_upgrade_lock);
taskq_cancel_id(os->os_spa->spa_upgrade_taskq, id);
if ((taskq_cancel_id(os->os_spa->spa_upgrade_taskq, id)) == 0) {
dsl_dataset_long_rele(dmu_objset_ds(os), upgrade_tag);
}
txg_wait_synced(os->os_spa->spa_dsl_pool, 0);
} else {
mutex_exit(&os->os_upgrade_lock);
}

View File

@ -5181,9 +5181,6 @@ zfs_ioc_userobjspace_upgrade(zfs_cmd_t *zc)
if (error != 0)
return (error);
dsl_dataset_long_hold(dmu_objset_ds(os), FTAG);
dsl_pool_rele(dmu_objset_pool(os), FTAG);
if (dmu_objset_userobjspace_upgradable(os)) {
mutex_enter(&os->os_upgrade_lock);
if (os->os_upgrade_id == 0) {
@ -5196,8 +5193,12 @@ zfs_ioc_userobjspace_upgrade(zfs_cmd_t *zc)
mutex_exit(&os->os_upgrade_lock);
}
dsl_pool_rele(dmu_objset_pool(os), FTAG);
taskq_wait_id(os->os_spa->spa_upgrade_taskq, os->os_upgrade_id);
error = os->os_upgrade_status;
} else {
dsl_pool_rele(dmu_objset_pool(os), FTAG);
}
dsl_dataset_long_rele(dmu_objset_ds(os), FTAG);

View File

@ -834,8 +834,13 @@ zfs_fuid_overobjquota(zfsvfs_t *zfsvfs, boolean_t isgroup, uint64_t fuid)
int err;
if (!dmu_objset_userobjspace_present(zfsvfs->z_os)) {
if (dmu_objset_userobjspace_upgradable(zfsvfs->z_os))
if (dmu_objset_userobjspace_upgradable(zfsvfs->z_os)) {
dsl_pool_config_enter(
dmu_objset_pool(zfsvfs->z_os), FTAG);
dmu_objset_userobjspace_upgrade(zfsvfs->z_os);
dsl_pool_config_exit(
dmu_objset_pool(zfsvfs->z_os), FTAG);
}
return (B_FALSE);
}