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f2fs: remove redundant lock_page calls

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In get_node_page, we do not need to call lock_page all the time.

If the node page is cached as uptodate,

1. grab_cache_page locks the page,
2. read_node_page unlocks the page, and
3. lock_page is called for further process.

Let's avoid this.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Jaegeuk Kim 2013-03-31 12:47:20 +09:00
parent 53cf95222f
commit 56ae674cc2
2 changed files with 28 additions and 15 deletions
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40
fs/f2fs/node.c
View File

@ -847,6 +847,12 @@ fail:
return ERR_PTR(err);
}
/*
* Caller should do after getting the following values.
* 0: f2fs_put_page(page, 0)
* LOCKED_PAGE: f2fs_put_page(page, 1)
* error: nothing
*/
static int read_node_page(struct page *page, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
@ -859,10 +865,8 @@ static int read_node_page(struct page *page, int type)
return -ENOENT;
}
if (PageUptodate(page)) {
unlock_page(page);
return 0;
}
if (PageUptodate(page))
return LOCKED_PAGE;
return f2fs_readpage(sbi, page, ni.blk_addr, type);
}
@ -874,6 +878,7 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
{
struct address_space *mapping = sbi->node_inode->i_mapping;
struct page *apage;
int err;
apage = find_get_page(mapping, nid);
if (apage && PageUptodate(apage)) {
@ -886,30 +891,36 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
if (!apage)
return;
if (read_node_page(apage, READA) == 0)
err = read_node_page(apage, READA);
if (err == 0)
f2fs_put_page(apage, 0);
else if (err == LOCKED_PAGE)
f2fs_put_page(apage, 1);
return;
}
struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
{
int err;
struct page *page;
struct address_space *mapping = sbi->node_inode->i_mapping;
struct page *page;
int err;
page = grab_cache_page(mapping, nid);
if (!page)
return ERR_PTR(-ENOMEM);
err = read_node_page(page, READ_SYNC);
if (err)
if (err < 0)
return ERR_PTR(err);
else if (err == LOCKED_PAGE)
goto got_it;
lock_page(page);
if (!PageUptodate(page)) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
got_it:
BUG_ON(nid != nid_of_node(page));
mark_page_accessed(page);
return page;
@ -923,10 +934,9 @@ struct page *get_node_page_ra(struct page *parent, int start)
{
struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
struct address_space *mapping = sbi->node_inode->i_mapping;
int i, end;
int err = 0;
nid_t nid;
struct page *page;
int err, i, end;
nid_t nid;
/* First, try getting the desired direct node. */
nid = get_nid(parent, start, false);
@ -936,12 +946,12 @@ struct page *get_node_page_ra(struct page *parent, int start)
page = grab_cache_page(mapping, nid);
if (!page)
return ERR_PTR(-ENOMEM);
else if (PageUptodate(page))
goto page_hit;
err = read_node_page(page, READ_SYNC);
if (err)
if (err < 0)
return ERR_PTR(err);
else if (err == LOCKED_PAGE)
goto page_hit;
/* Then, try readahead for siblings of the desired node */
end = start + MAX_RA_NODE;
@ -956,7 +966,7 @@ struct page *get_node_page_ra(struct page *parent, int start)
lock_page(page);
page_hit:
if (PageError(page)) {
if (!PageUptodate(page)) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}

3
fs/f2fs/node.h
View File

@ -29,6 +29,9 @@
/* vector size for gang look-up from nat cache that consists of radix tree */
#define NATVEC_SIZE 64
/* return value for read_node_page */
#define LOCKED_PAGE 1
/*
* For node information
*/