Cleanup sparse file support by creating worker function for it

Simply move code to new function (for clarity). Function sets or clears
the sparse file attribute flag.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: David Disseldorp <ddiss@samba.org>

fs/cifs/smb2ops.c

@@ -731,29 +731,21 @@ smb2_sync_write(const unsigned int xid, struct cifsFileInfo *cfile,
 	return SMB2_write(xid, parms, written, iov, nr_segs);
 }
 
-static int
-smb2_set_file_size(const unsigned int xid, struct cifs_tcon *tcon,
-		   struct cifsFileInfo *cfile, __u64 size, bool set_alloc)
+/* Set or clear the SPARSE_FILE attribute based on value passed in setsparse */
+static bool smb2_set_sparse(const unsigned int xid, struct cifs_tcon *tcon,
+		struct cifsFileInfo *cfile, struct inode *inode, __u8 setsparse)
 {
-	__le64 eof = cpu_to_le64(size);
-	struct inode *inode;
-
-	/*
-	 * If extending file more than one page make sparse. Many Linux fs
-	 * make files sparse by default when extending via ftruncate
-	 */
-	inode = cfile->dentry->d_inode;
-
-	if (!set_alloc && (size > inode->i_size + 8192)) {
 	struct cifsInodeInfo *cifsi;
-		__u8 set_sparse = 1;
 	int rc;
 
 	cifsi = CIFS_I(inode);
 
-		/* if file already sparse or no server support don't bother */
-		if (cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE)
-			goto smb2_set_eof;
+	/* if file already sparse don't bother setting sparse again */
+	if ((cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) && setsparse)
+		return true; /* already sparse */
+
+	if (!(cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) && !setsparse)
+		return true; /* already not sparse */
 
 	/*
 	 * Can't check for sparse support on share the usual way via the
@@ -766,19 +758,45 @@ smb2_set_file_size(const unsigned int xid, struct cifs_tcon *tcon,
 	 * if the file is repeatedly extended.
 	 */
 	if (tcon->broken_sparse_sup)
-			goto smb2_set_eof;
+		return false;
 
 	rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
 			cfile->fid.volatile_fid, FSCTL_SET_SPARSE,
-				true /* is_fctl */, &set_sparse, 1, NULL, NULL);
+			true /* is_fctl */, &setsparse, 1, NULL, NULL);
 	if (rc) {
 		tcon->broken_sparse_sup = true;
 		cifs_dbg(FYI, "set sparse rc = %d\n", rc);
-		} else
+		return false;
+	}
+
+	if (setsparse)
 		cifsi->cifsAttrs |= FILE_ATTRIBUTE_SPARSE_FILE;
+	else
+		cifsi->cifsAttrs &= (~FILE_ATTRIBUTE_SPARSE_FILE);
+
+	return true;
+}
+
+static int
+smb2_set_file_size(const unsigned int xid, struct cifs_tcon *tcon,
+		   struct cifsFileInfo *cfile, __u64 size, bool set_alloc)
+{
+	__le64 eof = cpu_to_le64(size);
+	struct inode *inode;
+
+	/*
+	 * If extending file more than one page make sparse. Many Linux fs
+	 * make files sparse by default when extending via ftruncate
+	 */
+	inode = cfile->dentry->d_inode;
+
+	if (!set_alloc && (size > inode->i_size + 8192)) {
+		__u8 set_sparse = 1;
+
+		/* whether set sparse succeeds or not, extend the file */
+		smb2_set_sparse(xid, tcon, cfile, inode, set_sparse);
 	}
 
-smb2_set_eof:
 	return SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
 			    cfile->fid.volatile_fid, cfile->pid, &eof, false);
 }