v9fs: don't use primary fid when removing file

v9fs_insert uses v9fs_fid_lookup (which also locks the fid) to get the
primary fid associated with the dentry and destroys the v9fs_fid struct
after removing the file.  If another process called v9fs_fid_lookup on the
same dentry, it may wait undefinitely for the fid's lock (as the struct is
freed).

This patch changes v9fs_remove to use a cloned fid, so the primary fid is
not locked and freed.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@hera.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 124a085..b01b0a4 100644 (file)
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -415,7 +415,7 @@ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
        file_inode = file->d_inode;
        sb = file_inode->i_sb;
        v9ses = v9fs_inode2v9ses(file_inode);
-       v9fid = v9fs_fid_lookup(file);
+       v9fid = v9fs_fid_clone(file);
        if(IS_ERR(v9fid))
                return PTR_ERR(v9fid);