jffs2: cache data_crc results
As we moved data_crc() invocation from jffs2_1pass_build_lists() to
jffs2_1pass_read_inode() data_crc is going to be calculated on each
inode access. This patch adds caching of data_crc() results. There
is no significant improvement in speed (because of flash access
caching added in previous patch I think, crc in RAM is really fast)
but this patch impacts memory usage -- every b_node structure uses
12 bytes instead of 8.
Signed-off-by: Alexey Neyman <avn@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
diff --git a/fs/jffs2/jffs2_1pass.c b/fs/jffs2/jffs2_1pass.c
index 4e49a05..be7c1a1 100644
--- a/fs/jffs2/jffs2_1pass.c
+++ b/fs/jffs2/jffs2_1pass.c
@@ -765,7 +765,10 @@
put_fl_mem(jNode, pL->readbuf);
continue;
}
- if (!data_crc(jNode)) {
+ if (b->datacrc == CRC_UNKNOWN)
+ b->datacrc = data_crc(jNode) ?
+ CRC_OK : CRC_BAD;
+ if (b->datacrc == CRC_BAD) {
put_fl_mem(jNode, pL->readbuf);
continue;
}
diff --git a/fs/jffs2/jffs2_private.h b/fs/jffs2/jffs2_private.h
index 3633dea..658b325 100644
--- a/fs/jffs2/jffs2_private.h
+++ b/fs/jffs2/jffs2_private.h
@@ -7,6 +7,7 @@
struct b_node {
u32 offset;
struct b_node *next;
+ enum { CRC_UNKNOWN = 0, CRC_OK, CRC_BAD } datacrc;
};
struct b_list {