cifs: Fix missing put_xid in cifs_file_strict_mmap

commit f04a703c3d613845ae3141bfaf223489de8ab3eb upstream.

If cifs_zap_mapping() returned an error, we would return without putting
the xid that we got earlier.  Restructure cifs_file_strict_mmap() and
cifs_file_mmap() to be more similar to each other and have a single
point of return that always puts the xid.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index f9d2863..a491aef 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2530,20 +2530,18 @@ static struct vm_operations_struct cifs_file_vm_ops = {
 
 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
 {
-       int rc, xid;
+       int xid, rc = 0;
        struct inode *inode = file->f_path.dentry->d_inode;
 
        xid = GetXid();
 
-       if (!CIFS_I(inode)->clientCanCacheRead) {
+       if (!CIFS_I(inode)->clientCanCacheRead)
                rc = cifs_invalidate_mapping(inode);
-               if (rc)
-                       return rc;
-       }
-
-       rc = generic_file_mmap(file, vma);
-       if (rc == 0)
+       if (!rc)
+               rc = generic_file_mmap(file, vma);
+       if (!rc)
                vma->vm_ops = &cifs_file_vm_ops;
+
        FreeXid(xid);
        return rc;
 }
@@ -2553,15 +2551,15 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
        int rc, xid;
 
        xid = GetXid();
+
        rc = cifs_revalidate_file(file);
-       if (rc) {
+       if (rc)
                cFYI(1, "Validation prior to mmap failed, error=%d", rc);
-               FreeXid(xid);
-               return rc;
-       }
-       rc = generic_file_mmap(file, vma);
-       if (rc == 0)
+       if (!rc)
+               rc = generic_file_mmap(file, vma);
+       if (!rc)
                vma->vm_ops = &cifs_file_vm_ops;
+
        FreeXid(xid);
        return rc;
 }