cifs: don't call cifs_new_fileinfo unless cifs_open succeeds

It's currently possible for cifs_open to fail after it has already
called cifs_new_fileinfo. In that situation, the new fileinfo will be
leaked as the caller doesn't call fput. That in turn leads to a busy
inodes after umount problem since the fileinfo holds an extra inode
reference now. Shuffle cifs_open around a bit so that it only calls
cifs_new_fileinfo if it's going to succeed.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>

1 files changed, 11 insertions, 6 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 02a2df9cdd9c..409e4f523e61 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -268,17 +268,20 @@ int cifs_open(struct inode *inode, struct file *file)
                         /* no need for special case handling of setting mode
                            on read only files needed here */
 
+                        rc = cifs_posix_open_inode_helper(inode, file,
+                                        pCifsInode, oplock, netfid);
+                        if (rc != 0) {
+                                CIFSSMBClose(xid, tcon, netfid);
+                                goto out;
+                        }
+
                         pCifsFile = cifs_new_fileinfo(inode, netfid, file,
                                                         file->f_path.mnt,
                                                         oflags);
                         if (pCifsFile == NULL) {
                                 CIFSSMBClose(xid, tcon, netfid);
                                 rc = -ENOMEM;
-                                goto out;
                         }
-
-                        rc = cifs_posix_open_inode_helper(inode, file,
-                                        pCifsInode, oplock, netfid);
                         goto out;
                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
                         if (tcon->ses->serverNOS)
@@ -359,6 +362,10 @@ int cifs_open(struct inode *inode, struct file *file)
                 goto out;
         }
 
+        rc = cifs_open_inode_helper(inode, tcon, &oplock, buf, full_path, xid);
+        if (rc != 0)
+                goto out;
+
         pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
                                         file->f_flags);
         if (pCifsFile == NULL) {
@@ -366,8 +373,6 @@ int cifs_open(struct inode *inode, struct file *file)
                 goto out;
         }
 
-        rc = cifs_open_inode_helper(inode, tcon, &oplock, buf, full_path, xid);
-
         if (oplock & CIFS_CREATE_ACTION) {
                 /* time to set mode which we can not set earlier due to
                    problems creating new read-only files */