[PATCH 3/7] cifs: smb2_close_getattr should also update i_size

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

SMB2 CLOSE command with SMB2_CLOSE_FLAG_POSTQUERY_ATTRIB
flag set is already used by the code for SMB3+.
smb2_close_getattr is the function that uses this to
update the inode attributes.

However, we were skipping the EndOfFile info that's returned
by the server. There is a small chance that the file size
may have been changed in the small window between the client
sending the close request (thereby giving up lease if it had)
to the point that the server returns the response.

This change uses the field to update the inode size.
Also, it is a valid case for a zero AllocationSize to be returned
by the server for the file. We were discarding such values, thereby
resulting in stale i_blocks value. Fixed that here too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/smb2ops.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index d9553c2556a2..e23577584ed6 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -1433,9 +1433,9 @@ smb2_close_getattr(const unsigned int xid, struct cifs_tcon *tcon,
 	 * but instead 512 byte (2**9) size is required for
 	 * calculating num blocks.
 	 */
-	if (le64_to_cpu(file_inf.AllocationSize) > 4096)
-		inode->i_blocks =
-			(512 - 1 + le64_to_cpu(file_inf.AllocationSize)) >> 9;
+	inode->i_blocks = (512 - 1 + le64_to_cpu(file_inf.AllocationSize)) >> 9;
+
+	inode->i_size = le64_to_cpu(file_inf.EndOfFile);
 
 	/* End of file and Attributes should not have to be updated on close */
 	spin_unlock(&inode->i_lock);
-- 
2.34.1