1 files changed, 91 insertions, 19 deletions

diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index 099bec94b820..d124117efd42 100644
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -365,20 +365,8 @@ static unsigned long long next_sqnum(struct ubifs_info *c)
 	return sqnum;
 }
 
-/**
- * ubifs_prepare_node - prepare node to be written to flash.
- * @c: UBIFS file-system description object
- * @node: the node to pad
- * @len: node length
- * @pad: if the buffer has to be padded
- *
- * This function prepares node at @node to be written to the media - it
- * calculates node CRC, fills the common header, and adds proper padding up to
- * the next minimum I/O unit if @pad is not zero.
- */
-void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
+void ubifs_init_node(struct ubifs_info *c, void *node, int len, int pad)
 {
-	uint32_t crc;
 	struct ubifs_ch *ch = node;
 	unsigned long long sqnum = next_sqnum(c);
 
@@ -389,8 +377,6 @@ void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
 	ch->group_type = UBIFS_NO_NODE_GROUP;
 	ch->sqnum = cpu_to_le64(sqnum);
 	ch->padding[0] = ch->padding[1] = 0;
-	crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
-	ch->crc = cpu_to_le32(crc);
 
 	if (pad) {
 		len = ALIGN(len, 8);
@@ -399,6 +385,68 @@ void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
 	}
 }
 
+void ubifs_crc_node(struct ubifs_info *c, void *node, int len)
+{
+	struct ubifs_ch *ch = node;
+	uint32_t crc;
+
+	crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
+	ch->crc = cpu_to_le32(crc);
+}
+
+/**
+ * ubifs_prepare_node_hmac - prepare node to be written to flash.
+ * @c: UBIFS file-system description object
+ * @node: the node to pad
+ * @len: node length
+ * @hmac_offs: offset of the HMAC in the node
+ * @pad: if the buffer has to be padded
+ *
+ * This function prepares node at @node to be written to the media - it
+ * calculates node CRC, fills the common header, and adds proper padding up to
+ * the next minimum I/O unit if @pad is not zero. if @hmac_offs is positive then
+ * a HMAC is inserted into the node at the given offset.
+ *
+ * This function returns 0 for success or a negative error code otherwise.
+ */
+int ubifs_prepare_node_hmac(struct ubifs_info *c, void *node, int len,
+			    int hmac_offs, int pad)
+{
+	int err;
+
+	ubifs_init_node(c, node, len, pad);
+
+	if (hmac_offs > 0) {
+		err = ubifs_node_insert_hmac(c, node, len, hmac_offs);
+		if (err)
+			return err;
+	}
+
+	ubifs_crc_node(c, node, len);
+
+	return 0;
+}
+
+/**
+ * ubifs_prepare_node - prepare node to be written to flash.
+ * @c: UBIFS file-system description object
+ * @node: the node to pad
+ * @len: node length
+ * @pad: if the buffer has to be padded
+ *
+ * This function prepares node at @node to be written to the media - it
+ * calculates node CRC, fills the common header, and adds proper padding up to
+ * the next minimum I/O unit if @pad is not zero.
+ */
+void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
+{
+	/*
+	 * Deliberately ignore return value since this function can only fail
+	 * when a hmac offset is given.
+	 */
+	ubifs_prepare_node_hmac(c, node, len, 0, pad);
+}
+
 /**
  * ubifs_prep_grp_node - prepare node of a group to be written to flash.
  * @c: UBIFS file-system description object
@@ -849,12 +897,13 @@ out:
 }
 
 /**
- * ubifs_write_node - write node to the media.
+ * ubifs_write_node_hmac - write node to the media.
  * @c: UBIFS file-system description object
  * @buf: the node to write
  * @len: node length
  * @lnum: logical eraseblock number
  * @offs: offset within the logical eraseblock
+ * @hmac_offs: offset of the HMAC within the node
  *
  * This function automatically fills node magic number, assigns sequence
  * number, and calculates node CRC checksum. The length of the @buf buffer has
@@ -862,8 +911,8 @@ out:
  * appends padding node and padding bytes if needed. Returns zero in case of
  * success and a negative error code in case of failure.
  */
-int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
-		     int offs)
+int ubifs_write_node_hmac(struct ubifs_info *c, void *buf, int len, int lnum,
+			  int offs, int hmac_offs)
 {
 	int err, buf_len = ALIGN(len, c->min_io_size);
 
@@ -878,7 +927,10 @@ int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
 	if (c->ro_error)
 		return -EROFS;
 
-	ubifs_prepare_node(c, buf, len, 1);
+	err = ubifs_prepare_node_hmac(c, buf, len, hmac_offs, 1);
+	if (err)
+		return err;
+
 	err = ubifs_leb_write(c, lnum, buf, offs, buf_len);
 	if (err)
 		ubifs_dump_node(c, buf);
@@ -887,6 +939,26 @@ int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
 }
 
 /**
+ * ubifs_write_node - write node to the media.
+ * @c: UBIFS file-system description object
+ * @buf: the node to write
+ * @len: node length
+ * @lnum: logical eraseblock number
+ * @offs: offset within the logical eraseblock
+ *
+ * This function automatically fills node magic number, assigns sequence
+ * number, and calculates node CRC checksum. The length of the @buf buffer has
+ * to be aligned to the minimal I/O unit size. This function automatically
+ * appends padding node and padding bytes if needed. Returns zero in case of
+ * success and a negative error code in case of failure.
+ */
+int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
+		     int offs)
+{
+	return ubifs_write_node_hmac(c, buf, len, lnum, offs, -1);
+}
+
+/**
  * ubifs_read_node_wbuf - read node from the media or write-buffer.
  * @wbuf: wbuf to check for un-written data
  * @buf: buffer to read to