Illumos 5056 - ZFS deadlock on db_mtx and dn_holds

5056 ZFS deadlock on db_mtx and dn_holds
Author: Justin Gibbs <justing@spectralogic.com>
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>

References:
  https://www.illumos.org/issues/5056
  https://github.com/illumos/illumos-gate/commit/bc9014e

Porting Notes:

sa_handle_get_from_db():
  - the original patch includes an otherwise unmentioned fix for a
    possible usage of an uninitialised variable

dmu_objset_open_impl():
  - Under Illumos list_link_init() is the same as filling a list_node_t
    with NULLs, so they don't notice if they miss doing list_link_init()
    on a zero'd containing structure (e.g. allocated with kmem_zalloc as
    here). Under Linux, not so much: an uninitialised list_node_t goes
    "Boom!" some time later when it's used or destroyed.

dmu_objset_evict_dbufs():
  - reduce stack usage using kmem_alloc()

Ported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This commit is contained in:
Justin T. Gibbs
2015-04-02 14:44:32 +11:00
committed by Brian Behlendorf
parent d683ddbb72
commit 0c66c32d1d
35 changed files with 645 additions and 316 deletions
+4 -6
View File
@@ -23,6 +23,7 @@
* Copyright (c) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013, Joyent, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
*/
#ifndef _SYS_DSL_DATASET_H
@@ -125,11 +126,14 @@ typedef struct dsl_dataset_phys {
} dsl_dataset_phys_t;
typedef struct dsl_dataset {
dmu_buf_user_t ds_dbu;
/* Immutable: */
struct dsl_dir *ds_dir;
dmu_buf_t *ds_dbuf;
uint64_t ds_object;
uint64_t ds_fsid_guid;
boolean_t ds_is_snapshot;
/* only used in syncing context, only valid for non-snapshots: */
struct dsl_dataset *ds_prev;
@@ -188,12 +192,6 @@ dsl_dataset_phys(dsl_dataset_t *ds)
*/
#define MAX_TAG_PREFIX_LEN 17
static inline boolean_t
dsl_dataset_is_snapshot(dsl_dataset_t *ds)
{
return (dsl_dataset_phys(ds)->ds_num_children != 0);
}
#define DS_UNIQUE_IS_ACCURATE(ds) \
((dsl_dataset_phys(ds)->ds_flags & DS_FLAG_UNIQUE_ACCURATE) != 0)