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| author | Jan Kara <jack@suse.cz> | 2014-04-03 14:46:56 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:20:54 -0700 |
| commit | e3a767b60fd8a9f5e133f42f4970cff77ec43173 (patch) | |
| tree | a8399e9f83f246bcaf7be821da534754d0c37692 /fs/ocfs2/ocfs2.h | |
| parent | 9f985cb6c45bc3f8b7e161c9658d409d051d576f (diff) | |
| download | lwn-e3a767b60fd8a9f5e133f42f4970cff77ec43173.tar.gz lwn-e3a767b60fd8a9f5e133f42f4970cff77ec43173.zip | |
ocfs2: implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference to
a workqueue if it happens from the downconvert thread.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/ocfs2.h')
| -rw-r--r-- | fs/ocfs2/ocfs2.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 553f53cc73ae..64c02239ba46 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -30,6 +30,7 @@ #include <linux/sched.h> #include <linux/wait.h> #include <linux/list.h> +#include <linux/llist.h> #include <linux/rbtree.h> #include <linux/workqueue.h> #include <linux/kref.h> @@ -419,6 +420,10 @@ struct ocfs2_super struct ocfs2_dentry_lock *dentry_lock_list; struct work_struct dentry_lock_work; + /* List of dquot structures to drop last reference to */ + struct llist_head dquot_drop_list; + struct work_struct dquot_drop_work; + wait_queue_head_t osb_mount_event; /* Truncate log info */ |