commit 8da5ff23ce0a84d9845b01e6fe5047e17836bf5a
author Miklos Szeredi <miklos@szeredi.hu> Tue Oct 17 00:10:08 2006 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> Tue Oct 17 08:18:45 2006 -0700
tree dc711306a3793c91a5df7fc0223738a40ea3fb7c
parent 7762f5a0b709b415fda132258ad37b9f2a1db994

[PATCH] fuse: locking fix for nlookup

An inode could be returned by independent parallel lookups, in this case an
update of the lookup counter could be lost resulting in a memory leak in
userspace.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/fuse/dir.c

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index a8f65c1..7ecfe95 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -163,7 +163,9 @@
 				fuse_send_forget(fc, req, outarg.nodeid, 1);
 				return 0;
 			}
+			spin_lock(&fc->lock);
 			fi->nlookup ++;
+			spin_unlock(&fc->lock);
 		}
 		fuse_put_request(fc, req);
 		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)

fs/fuse/inode.c

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 8e10616..e911423 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -195,7 +195,9 @@
 	}
 
 	fi = get_fuse_inode(inode);
+	spin_lock(&fc->lock);
 	fi->nlookup ++;
+	spin_unlock(&fc->lock);
 	fuse_change_attributes(inode, attr);
 	return inode;
 }