[patch] Move CRC computation to separate function

[Joel Reardon]

This patch moves the computation of CRCs for data nodes from 
within ubifs_prepare_node to a separate function ubifs_set_datanode_crc, 
which takes a data node, and computes and sets the CRC. This is to avoid 
duplication of the CRC computation code in other places where it may be 
needed.

Signed-off-by: Joel Reardon <reardonj@xxxxxxxxxxx>
diff -uprN -X linux-3.2.1-vanilla/Documentation/dontdiff 
linux-3.2.1-vanilla/fs/ubifs/io.c linux-3.2.1-ubifsec/fs/ubifs/io.c
--- linux-3.2.1-vanilla/fs/ubifs/io.c   2012-01-12 20:42:45.000000000 
+0100
+++ linux-3.2.1-ubifsec/fs/ubifs/io.c   2012-02-20 20:17:48.796684293 
+0100
@@ -367,6 +367,18 @@ static unsigned long long next_sqnum(str
 }

 /**
+ * ubifs_set_datanode_crc - writes the crc for a data node to the common
+ * header.
+ * @node: the data node
+ */
+void ubifs_set_datanode_crc(void *node)
+{
+       struct ubifs_ch *ch = (struct ubifs_ch *) node;
+       int len = le32_to_cpu(ch->len);
+       ch->crc = cpu_to_le32(crc32(UBIFS_CRC32_INIT, node + 8, len - 8));
+}
+
+/**
  * ubifs_prepare_node - prepare node to be written to flash.
  * @c: UBIFS file-system description object
  * @node: the node to pad
@@ -379,7 +391,6 @@ static unsigned long long next_sqnum(str
  */
 void ubifs_prepare_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);

@@ -390,8 +401,7 @@ void ubifs_prepare_node(struct ubifs_inf
        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);
+       ubifs_set_datanode_crc(node);

        if (pad) {
                len = ALIGN(len, 8);
diff -uprN -X linux-3.2.1-vanilla/Documentation/dontdiff 
linux-3.2.1-vanilla/fs/ubifs/ubifs.h linux-3.2.1-ubifsec/fs/ubifs/ubifs.h
--- linux-3.2.1-vanilla/fs/ubifs/ubifs.h        2012-01-12 
20:42:45.000000000 +0100
+++ linux-3.2.1-ubifsec/fs/ubifs/ubifs.h        2012-02-20 
20:18:17.368685674 +0100
@@ -1489,6 +1489,7 @@ int ubifs_write_node(struct ubifs_info *
                     int offs, int dtype);
 int ubifs_check_node(const struct ubifs_info *c, const void *buf, int 
lnum,
                     int offs, int quiet, int must_chk_crc);
+void ubifs_set_datanode_crc(void *node);
 void ubifs_prepare_node(struct ubifs_info *c, void *buf, int len, int 
pad);
 void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int 
last);
 int ubifs_io_init(struct ubifs_info *c);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/