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/data.c b/fs/f2fs/data.c
index 7bd22a2..277966a 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -183,7 +183,7 @@
f2fs_put_page(page, 0);
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)
return ERR_PTR(err);
f2fs_put_dnode(&dn);
@@ -222,7 +222,7 @@
int err;
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)
return ERR_PTR(err);
f2fs_put_dnode(&dn);
@@ -262,7 +262,7 @@
int err;
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, index, 0);
+ err = get_dnode_of_data(&dn, index, ALLOC_NODE);
if (err)
return ERR_PTR(err);
@@ -392,7 +392,7 @@
/* When reading holes, we need its node page */
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, pgofs, RDONLY_NODE);
+ err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
if (err)
return (err == -ENOENT) ? 0 : err;
@@ -443,7 +443,7 @@
int err = 0;
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, page->index, RDONLY_NODE);
+ err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
if (err)
return err;
@@ -607,7 +607,7 @@
mutex_lock_op(sbi, DATA_NEW);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, index, 0);
+ err = get_dnode_of_data(&dn, index, ALLOC_NODE);
if (err) {
mutex_unlock_op(sbi, DATA_NEW);
f2fs_put_page(page, 1);