Commit 266e97a8 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

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: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
parent 66d36a29
......@@ -183,7 +183,7 @@ struct page *find_data_page(struct inode *inode, pgoff_t index)
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 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
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 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
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 @@ static int get_data_block_ro(struct inode *inode, sector_t iblock,
/* 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 do_write_data_page(struct page *page)
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 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
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);
......
......@@ -125,11 +125,15 @@ static inline int update_sits_in_cursum(struct f2fs_summary_block *rs, int i)
* file keeping -1 as its node offset to
* distinguish from index node blocks.
*/
#define RDONLY_NODE 1 /*
* specify a read-only mode when getting
* a node block. 0 is read-write mode.
* used by get_dnode_of_data().
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.
*/
};
#define F2FS_LINK_MAX 32000 /* maximum link count per file */
/* for in-memory extent cache entry */
......
......@@ -43,7 +43,7 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
/* 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 @@ static int truncate_blocks(struct inode *inode, u64 from)
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 @@ int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
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 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
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;
......
......@@ -384,7 +384,7 @@ static int get_node_path(long block, int offset[4], unsigned int noffset[4])
/*
* Caller should call f2fs_put_dnode(dn).
*/
int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int ro)
int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
{
struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
struct page *npage[4];
......@@ -411,7 +411,7 @@ int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int ro)
for (i = 1; i <= level; i++) {
bool done = false;
if (!nids[i] && !ro) {
if (!nids[i] && mode == ALLOC_NODE) {
mutex_lock_op(sbi, NODE_NEW);
/* alloc new node */
......@@ -434,7 +434,7 @@ int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int ro)
alloc_nid_done(sbi, nids[i]);
mutex_unlock_op(sbi, NODE_NEW);
done = true;
} else if (ro && i == level && level > 1) {
} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
npage[i] = get_node_page_ra(parent, offset[i - 1]);
if (IS_ERR(npage[i])) {
err = PTR_ERR(npage[i]);
......
......@@ -247,7 +247,7 @@ static void do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
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);
......
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