[CIFS] lock inode open file list in close in case racing with open

Harmless since it only protected turning off caching for the
inode, but cleaner to lock around this in case we have a close
racing with open.

Signed-off-by: Shaggy <shaggy@us.ibm.com>
CC: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index b1807fd1ac4030ed7d6e7bf802d9ae2677e1f392..79254919386539d5a4883f44b96a1581dcebbec0 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -545,6 +545,7 @@ int cifs_close(struct inode *inode, struct file *file)
        } else
                rc = -EBADF;
 
+       read_lock(&GlobalSMBSeslock);
        if (list_empty(&(CIFS_I(inode)->openFileList))) {
                cFYI(1, ("closing last open instance for inode %p", inode));
                /* if the file is not open we do not know if we can cache info
@@ -552,6 +553,7 @@ int cifs_close(struct inode *inode, struct file *file)
                CIFS_I(inode)->clientCanCacheRead = FALSE;
                CIFS_I(inode)->clientCanCacheAll  = FALSE;
        }
+       read_unlock(&GlobalSMBSeslock);
        if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
                rc = CIFS_I(inode)->write_behind_rc;
        FreeXid(xid);