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/file.c b/fs/f2fs/file.c
index 958a46d..269645e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -43,7 +43,7 @@
/* block allocation */
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, page->index, 0);
+ err = get_dnode_of_data(&dn, page->index, ALLOC_NODE);
if (err) {
mutex_unlock_op(sbi, DATA_NEW);
goto out;
@@ -258,7 +258,7 @@
mutex_lock_op(sbi, DATA_TRUNC);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, free_from, RDONLY_NODE);
+ err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE);
if (err) {
if (err == -ENOENT)
goto free_next;
@@ -420,7 +420,7 @@
mutex_lock_op(sbi, DATA_TRUNC);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, index, RDONLY_NODE);
+ err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
if (err) {
mutex_unlock_op(sbi, DATA_TRUNC);
if (err == -ENOENT)
@@ -504,7 +504,7 @@
mutex_lock_op(sbi, DATA_NEW);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- ret = get_dnode_of_data(&dn, index, 0);
+ ret = get_dnode_of_data(&dn, index, ALLOC_NODE);
if (ret) {
mutex_unlock_op(sbi, DATA_NEW);
break;