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authorjiangyiwen <jiangyiwen@huawei.com>2016-03-25 14:21:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-25 16:37:42 -0700
commit35ddf78e41852cbbd216948425a091ab9815678f (patch)
tree34d4ccd01c6a3bee717c545ecc0199d8c4213fd3 /fs/ocfs2/super.c
parentbe12b299a83fc807bbaccd2bcb8ec50cbb0cb55c (diff)
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ocfs2: fix occurring deadlock by changing ocfs2_wq from global to local
This patch fixes a deadlock, as follows: Node 1 Node 2 Node 3 1)volume a and b are only mount vol a only mount vol b mounted 2) start to mount b start to mount a 3) check hb of Node 3 check hb of Node 2 in vol a, qs_holds++ in vol b, qs_holds++ 4) -------------------- all nodes' network down -------------------- 5) progress of mount b the same situation as failed, and then call Node 2 ocfs2_dismount_volume. but the process is hung, since there is a work in ocfs2_wq cannot beo completed. This work is about vol a, because ocfs2_wq is global wq. BTW, this work which is scheduled in ocfs2_wq is ocfs2_orphan_scan_work, and the context in this work needs to take inode lock of orphan_dir, because lockres owner are Node 1 and all nodes' nework has been down at the same time, so it can't get the inode lock. 6) Why can't this node be fenced when network disconnected? Because the process of mount is hung what caused qs_holds is not equal 0. Because all works in the ocfs2_wq are relative to the super block. The solution is to change the ocfs2_wq from global to local. In other words, move it into struct ocfs2_super. Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Xue jiufei <xuejiufei@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/super.c')
-rw-r--r--fs/ocfs2/super.c37
1 files changed, 15 insertions, 22 deletions
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index e2c4e3839d7b..7db631e1c8b0 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -80,12 +80,6 @@ static struct kmem_cache *ocfs2_inode_cachep;
struct kmem_cache *ocfs2_dquot_cachep;
struct kmem_cache *ocfs2_qf_chunk_cachep;
-/* OCFS2 needs to schedule several different types of work which
- * require cluster locking, disk I/O, recovery waits, etc. Since these
- * types of work tend to be heavy we avoid using the kernel events
- * workqueue and schedule on our own. */
-struct workqueue_struct *ocfs2_wq = NULL;
-
static struct dentry *ocfs2_debugfs_root;
MODULE_AUTHOR("Oracle");
@@ -1613,33 +1607,25 @@ static int __init ocfs2_init(void)
if (status < 0)
goto out2;
- ocfs2_wq = create_singlethread_workqueue("ocfs2_wq");
- if (!ocfs2_wq) {
- status = -ENOMEM;
- goto out3;
- }
-
ocfs2_debugfs_root = debugfs_create_dir("ocfs2", NULL);
if (!ocfs2_debugfs_root) {
status = -ENOMEM;
mlog(ML_ERROR, "Unable to create ocfs2 debugfs root.\n");
- goto out4;
+ goto out3;
}
ocfs2_set_locking_protocol();
status = register_quota_format(&ocfs2_quota_format);
if (status < 0)
- goto out4;
+ goto out3;
status = register_filesystem(&ocfs2_fs_type);
if (!status)
return 0;
unregister_quota_format(&ocfs2_quota_format);
-out4:
- destroy_workqueue(ocfs2_wq);
- debugfs_remove(ocfs2_debugfs_root);
out3:
+ debugfs_remove(ocfs2_debugfs_root);
ocfs2_free_mem_caches();
out2:
exit_ocfs2_uptodate_cache();
@@ -1650,11 +1636,6 @@ out1:
static void __exit ocfs2_exit(void)
{
- if (ocfs2_wq) {
- flush_workqueue(ocfs2_wq);
- destroy_workqueue(ocfs2_wq);
- }
-
unregister_quota_format(&ocfs2_quota_format);
debugfs_remove(ocfs2_debugfs_root);
@@ -2349,6 +2330,12 @@ static int ocfs2_initialize_super(struct super_block *sb,
}
cleancache_init_shared_fs(sb);
+ osb->ocfs2_wq = create_singlethread_workqueue("ocfs2_wq");
+ if (!osb->ocfs2_wq) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ }
+
bail:
return status;
}
@@ -2536,6 +2523,12 @@ static void ocfs2_delete_osb(struct ocfs2_super *osb)
{
/* This function assumes that the caller has the main osb resource */
+ /* ocfs2_initializer_super have already created this workqueue */
+ if (osb->ocfs2_wq) {
+ flush_workqueue(osb->ocfs2_wq);
+ destroy_workqueue(osb->ocfs2_wq);
+ }
+
ocfs2_free_slot_info(osb);
kfree(osb->osb_orphan_wipes);