afs: Fix setting of i_blocks

The setting of i_blocks, which is calculated from i_size, has got
accidentally misordered relative to the setting of i_size when initially
setting up an inode.  Further, i_blocks isn't updated by afs_apply_status()
when the size is updated.

To fix this, break the i_size/i_blocks setting out into a helper function
and call it from both places.

Fixes: a58823ac4589 ("afs: Fix application of status and callback to be under same lock")
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index dd89313..18a50d4 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -56,6 +56,16 @@ static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *paren
 }
 
 /*
+ * Set the file size and block count.  Estimate the number of 512 bytes blocks
+ * used, rounded up to nearest 1K for consistency with other AFS clients.
+ */
+static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
+{
+	i_size_write(&vnode->vfs_inode, size);
+	vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
+}
+
+/*
  * Initialise an inode from the vnode status.
  */
 static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
@@ -124,12 +134,7 @@ static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
 		return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type);
 	}
 
-	/*
-	 * Estimate 512 bytes  blocks used, rounded up to nearest 1K
-	 * for consistency with other AFS clients.
-	 */
-	inode->i_blocks		= ((i_size_read(inode) + 1023) >> 10) << 1;
-	i_size_write(&vnode->vfs_inode, status->size);
+	afs_set_i_size(vnode, status->size);
 
 	vnode->invalid_before	= status->data_version;
 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
@@ -232,7 +237,7 @@ static void afs_apply_status(struct afs_fs_cursor *fc,
 
 	if (data_changed) {
 		inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
-		i_size_write(&vnode->vfs_inode, status->size);
+		afs_set_i_size(vnode, status->size);
 	}
 }