f2fs: use bitmap in discard_entry
This patch changes to use bitmap instead of extent in struct discard_entry
to indicate discard range in one segment, for fragmented space, this
implementation can save memory footprint.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 8741d51..43b6e1e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -182,11 +182,11 @@ struct inode_entry {
struct inode *inode; /* vfs inode pointer */
};
-/* for the list of blockaddresses to be discarded */
+/* for the bitmap indicate blocks to be discarded */
struct discard_entry {
struct list_head list; /* list head */
- block_t blkaddr; /* block address to be discarded */
- int len; /* # of consecutive blocks of the discard */
+ block_t start_blkaddr; /* start blockaddr of current segment */
+ unsigned char discard_map[SIT_VBLOCK_MAP_SIZE]; /* segment discard bitmap */
};
enum {