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author | mav <mav@FreeBSD.org> | 2015-10-03 07:29:56 +0000 |
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committer | mav <mav@FreeBSD.org> | 2015-10-03 07:29:56 +0000 |
commit | 4a52577541ebbe34a9fa8abe3948a8514c63258c (patch) | |
tree | 8ed8ab1f80ef30fc8881b08dd4e4e6ea57f4f7c3 /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c | |
parent | 3529a708dddb3cca632de7b55ab67db8aa2f543d (diff) | |
download | FreeBSD-src-4a52577541ebbe34a9fa8abe3948a8514c63258c.zip FreeBSD-src-4a52577541ebbe34a9fa8abe3948a8514c63258c.tar.gz |
MFC r286575: 5056 ZFS deadlock on db_mtx and dn_holds
Reviewed by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Justin Gibbs <justing@spectralogic.com>
illumos/illumos-gate@bc9014e6a81272073b9854d9f65dd59e18d18c35
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c')
-rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c | 111 |
1 files changed, 68 insertions, 43 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c index eb6f3d1..88edcda 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c @@ -23,6 +23,7 @@ * Copyright (c) 2012, 2014 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2013, Joyent, Inc. All rights reserved. + * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. * Copyright 2015 Nexenta Systems, Inc. All rights reserved. */ @@ -357,7 +358,7 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, zfs_prop_to_name(ZFS_PROP_SECONDARYCACHE), secondary_cache_changed_cb, os); } - if (!dsl_dataset_is_snapshot(ds)) { + if (!ds->ds_is_snapshot) { if (err == 0) { err = dsl_prop_register(ds, zfs_prop_to_name(ZFS_PROP_CHECKSUM), @@ -419,7 +420,7 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, os->os_secondary_cache = ZFS_CACHE_ALL; } - if (ds == NULL || !dsl_dataset_is_snapshot(ds)) + if (ds == NULL || !ds->ds_is_snapshot) os->os_zil_header = os->os_phys->os_zil_header; os->os_zil = zil_alloc(os, &os->os_zil_header); @@ -438,16 +439,13 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp, mutex_init(&os->os_obj_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&os->os_user_ptr_lock, NULL, MUTEX_DEFAULT, NULL); - DMU_META_DNODE(os) = dnode_special_open(os, - &os->os_phys->os_meta_dnode, DMU_META_DNODE_OBJECT, - &os->os_meta_dnode); + dnode_special_open(os, &os->os_phys->os_meta_dnode, + DMU_META_DNODE_OBJECT, &os->os_meta_dnode); if (arc_buf_size(os->os_phys_buf) >= sizeof (objset_phys_t)) { - DMU_USERUSED_DNODE(os) = dnode_special_open(os, - &os->os_phys->os_userused_dnode, DMU_USERUSED_OBJECT, - &os->os_userused_dnode); - DMU_GROUPUSED_DNODE(os) = dnode_special_open(os, - &os->os_phys->os_groupused_dnode, DMU_GROUPUSED_OBJECT, - &os->os_groupused_dnode); + dnode_special_open(os, &os->os_phys->os_userused_dnode, + DMU_USERUSED_OBJECT, &os->os_userused_dnode); + dnode_special_open(os, &os->os_phys->os_groupused_dnode, + DMU_GROUPUSED_OBJECT, &os->os_groupused_dnode); } *osp = os; @@ -535,7 +533,7 @@ dmu_objset_own(const char *name, dmu_objset_type_t type, } else if (type != DMU_OST_ANY && type != (*osp)->os_phys->os_type) { dsl_dataset_disown(ds, tag); return (SET_ERROR(EINVAL)); - } else if (!readonly && dsl_dataset_is_snapshot(ds)) { + } else if (!readonly && ds->ds_is_snapshot) { dsl_dataset_disown(ds, tag); return (SET_ERROR(EROFS)); } @@ -591,41 +589,53 @@ dmu_objset_disown(objset_t *os, void *tag) void dmu_objset_evict_dbufs(objset_t *os) { + dnode_t dn_marker; dnode_t *dn; mutex_enter(&os->os_lock); + dn = list_head(&os->os_dnodes); + while (dn != NULL) { + /* + * Skip dnodes without holds. We have to do this dance + * because dnode_add_ref() only works if there is already a + * hold. If the dnode has no holds, then it has no dbufs. + */ + if (dnode_add_ref(dn, FTAG)) { + list_insert_after(&os->os_dnodes, dn, &dn_marker); + mutex_exit(&os->os_lock); - /* process the mdn last, since the other dnodes have holds on it */ - list_remove(&os->os_dnodes, DMU_META_DNODE(os)); - list_insert_tail(&os->os_dnodes, DMU_META_DNODE(os)); - - /* - * Find the first dnode with holds. We have to do this dance - * because dnode_add_ref() only works if you already have a - * hold. If there are no holds then it has no dbufs so OK to - * skip. - */ - for (dn = list_head(&os->os_dnodes); - dn && !dnode_add_ref(dn, FTAG); - dn = list_next(&os->os_dnodes, dn)) - continue; - - while (dn) { - dnode_t *next_dn = dn; - - do { - next_dn = list_next(&os->os_dnodes, next_dn); - } while (next_dn && !dnode_add_ref(next_dn, FTAG)); + dnode_evict_dbufs(dn); + dnode_rele(dn, FTAG); - mutex_exit(&os->os_lock); - dnode_evict_dbufs(dn); - dnode_rele(dn, FTAG); - mutex_enter(&os->os_lock); - dn = next_dn; + mutex_enter(&os->os_lock); + dn = list_next(&os->os_dnodes, &dn_marker); + list_remove(&os->os_dnodes, &dn_marker); + } else { + dn = list_next(&os->os_dnodes, dn); + } } mutex_exit(&os->os_lock); + + if (DMU_USERUSED_DNODE(os) != NULL) { + dnode_evict_dbufs(DMU_GROUPUSED_DNODE(os)); + dnode_evict_dbufs(DMU_USERUSED_DNODE(os)); + } + dnode_evict_dbufs(DMU_META_DNODE(os)); } +/* + * Objset eviction processing is split into into two pieces. + * The first marks the objset as evicting, evicts any dbufs that + * have a refcount of zero, and then queues up the objset for the + * second phase of eviction. Once os->os_dnodes has been cleared by + * dnode_buf_pageout()->dnode_destroy(), the second phase is executed. + * The second phase closes the special dnodes, dequeues the objset from + * the list of those undergoing eviction, and finally frees the objset. + * + * NOTE: Due to asynchronous eviction processing (invocation of + * dnode_buf_pageout()), it is possible for the meta dnode for the + * objset to have no holds even though os->os_dnodes is not empty. + */ void dmu_objset_evict(objset_t *os) { @@ -635,7 +645,7 @@ dmu_objset_evict(objset_t *os) ASSERT(!dmu_objset_is_dirty(os, t)); if (ds) { - if (!dsl_dataset_is_snapshot(ds)) { + if (!ds->ds_is_snapshot) { VERIFY0(dsl_prop_unregister(ds, zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum_changed_cb, os)); @@ -672,8 +682,24 @@ dmu_objset_evict(objset_t *os) if (os->os_sa) sa_tear_down(os); + os->os_evicting = B_TRUE; dmu_objset_evict_dbufs(os); + mutex_enter(&os->os_lock); + spa_evicting_os_register(os->os_spa, os); + if (list_is_empty(&os->os_dnodes)) { + mutex_exit(&os->os_lock); + dmu_objset_evict_done(os); + } else { + mutex_exit(&os->os_lock); + } +} + +void +dmu_objset_evict_done(objset_t *os) +{ + ASSERT3P(list_head(&os->os_dnodes), ==, NULL); + dnode_special_close(&os->os_meta_dnode); if (DMU_USERUSED_DNODE(os)) { dnode_special_close(&os->os_userused_dnode); @@ -681,8 +707,6 @@ dmu_objset_evict(objset_t *os) } zil_free(os->os_zil); - ASSERT3P(list_head(&os->os_dnodes), ==, NULL); - VERIFY(arc_buf_remove_ref(os->os_phys_buf, &os->os_phys_buf)); /* @@ -697,6 +721,7 @@ dmu_objset_evict(objset_t *os) mutex_destroy(&os->os_lock); mutex_destroy(&os->os_obj_lock); mutex_destroy(&os->os_user_ptr_lock); + spa_evicting_os_deregister(os->os_spa, os); kmem_free(os, sizeof (objset_t)); } @@ -895,7 +920,7 @@ dmu_objset_clone_check(void *arg, dmu_tx_t *tx) return (error); /* You can only clone snapshots, not the head datasets. */ - if (!dsl_dataset_is_snapshot(origin)) { + if (!origin->ds_is_snapshot) { dsl_dataset_rele(origin, FTAG); return (SET_ERROR(EINVAL)); } @@ -1459,7 +1484,7 @@ int dmu_objset_is_snapshot(objset_t *os) { if (os->os_dsl_dataset != NULL) - return (dsl_dataset_is_snapshot(os->os_dsl_dataset)); + return (os->os_dsl_dataset->ds_is_snapshot); else return (B_FALSE); } |