[PATCH] 9p: fix segfault caused by race condition in meta-data operations
Running dbench multithreaded exposed a race condition where fid structures
were removed while in use. This patch adds semaphores to meta-data operations
to protect the fid structure. Some cleanup of error-case handling in the
inode operations is also included.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index aa974d6..48fc170 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -30,6 +30,8 @@
struct list_head list; /* list of fids associated with a dentry */
struct list_head active; /* XXX - debug */
+ struct semaphore lock;
+
u32 fid;
unsigned char fidopen; /* set when fid is opened */
unsigned char fidclunked; /* set when fid has already been clunked */
@@ -55,3 +57,6 @@
void v9fs_fid_destroy(struct v9fs_fid *fid);
struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *, int fid);
int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry);
+struct v9fs_fid *v9fs_fid_clone(struct dentry *dentry);
+void v9fs_fid_clunk(struct v9fs_session_info *v9ses, struct v9fs_fid *fid);
+