From c0daec32f839f687a7b631ea8c292dfb2637478a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Arkadiusz=20Buba=C5=82a?= Date: Fri, 10 Nov 2017 22:37:10 +0100 Subject: [PATCH] Long hold the dataset during upgrade MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Arkadiusz Bubała Closes #5295 Closes #6837 --- module/zfs/dmu_objset.c | 18 ++++++++++++++---- module/zfs/zfs_ioctl.c | 8 ++++---- module/zfs/zfs_vfsops.c | 7 ++++++- 3 files changed, 24 insertions(+), 9 deletions(-) diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c index fca936ac2a..e596b70e9c 100644 --- a/module/zfs/dmu_objset.c +++ b/module/zfs/dmu_objset.c @@ -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 */ @@ -79,6 +80,8 @@ 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); @@ -704,13 +707,12 @@ dmu_objset_own(const char *name, dmu_objset_type_t type, return (err); } - dsl_pool_rele(dp, FTAG); - /* user accounting requires the dataset to be decrypted */ if (dmu_objset_userobjspace_upgradable(*osp) && (ds->ds_dir->dd_crypto_obj == 0 || decrypt)) dmu_objset_userobjspace_upgrade(*osp); + dsl_pool_rele(dp, FTAG); return (0); } @@ -1311,6 +1313,7 @@ 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 @@ -1319,6 +1322,9 @@ 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; @@ -1326,8 +1332,10 @@ 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); } @@ -1343,7 +1351,9 @@ 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); diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c index 9bd9b58bad..b132a68859 100644 --- a/module/zfs/zfs_ioctl.c +++ b/module/zfs/zfs_ioctl.c @@ -5275,9 +5275,6 @@ 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) { @@ -5290,11 +5287,14 @@ 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); dsl_dataset_rele_flags(dmu_objset_ds(os), DS_HOLD_FLAG_DECRYPT, FTAG); return (error); diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c index 33557157b6..af5593c2e0 100644 --- a/module/zfs/zfs_vfsops.c +++ b/module/zfs/zfs_vfsops.c @@ -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); }