From: Matthew Wilcox <mawilcox@microsoft.com>
Date: Fri, 15 Dec 2017 20:48:32 +0000 (-0800)
Subject: cifs: Fix missing put_xid in cifs_file_strict_mmap
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=369813ffa51bbc02e0932fb2dd1e5f3374789dfa;hp=50a44c165a67ff0b7e14d221af6cb6c1035aa90a

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 f9d28635a702..a491aefc9b60 100644
--- 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;
 }