f2fs: introduce readahead mode of node pages
Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.
- get_data_block_ro
- get_lock_data_page
- do_write_data_page
- truncate_blocks
- truncate_hole
However, this readahead mechanism is initially introduced for the use of
get_data_block_ro to enhance the sequential read performance.
So, let's clarify all the cases with the additional modes as follows.
enum {
ALLOC_NODE, /* allocate a new node page if needed */
LOOKUP_NODE, /* look up a node without readahead */
LOOKUP_NODE_RA, /*
* look up a node with readahead called
* by get_datablock_ro.
*/
}
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index b235215..6b82e20 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -247,7 +247,7 @@
end = start + ADDRS_PER_BLOCK;
set_new_dnode(&dn, inode, NULL, NULL, 0);
- if (get_dnode_of_data(&dn, start, 0))
+ if (get_dnode_of_data(&dn, start, ALLOC_NODE))
return;
wait_on_page_writeback(dn.node_page);