RE: [f2fs-dev] [PATCH 3/3 V2] f2fs: introduce f2fs_cache_node_page()to add page into node_inode cache

From: Chao Yu
Date: Sun Dec 08 2013 - 21:16:09 EST


Hi,

> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk.kim@xxxxxxxxxxx]
> Sent: Monday, December 09, 2013 7:37 AM
> To: Chao Yu
> Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [f2fs-dev] [PATCH 3/3 V2] f2fs: introduce f2fs_cache_node_page() to add page into node_inode cache
>
> 2013-12-06 (ê), 17:10 +0800, Chao Yu:
> > This patch introduces f2fs_cache_node_page(), in this function, page which is
> > readed ahead will be copy to node_inode's mapping cache.
> > It will avoid rereading these node pages.
> >
> > change log:
> > o check validity of grabbed page suggested by Jaegeuk Kim.
> >
> > Suggested-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
> > Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
> > ---
> > fs/f2fs/node.c | 35 +++++++++++++++++++++++++++++++++++
> > 1 file changed, 35 insertions(+)
> >
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 099f06f..3ff98fa 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1600,6 +1600,39 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > return 0;
> > }
> >
> > +/*
> > + * f2fs_cache_node_page() copy updated page data to node_inode cache page.
> > + */
> > +void f2fs_cache_node_page(struct f2fs_sb_info *sbi, struct page *page,
> > + nid_t nid)
> > +{
> > + struct address_space *mapping = sbi->node_inode->i_mapping;
> > + struct page *npage;
>
>
> What I meant for the validity was to check the block address to figure
> out this node page is up-to-date or not.
> IOW, something like this.

Yes, you're right.

So, how about the this one?
---
fs/f2fs/node.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 099f06f..3e7a336 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1600,13 +1600,46 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
return 0;
}

+/*
+ * f2fs_cache_node_page() check validaty of input page by searching NAT.
+ * Then, it will copy updated data of vaild page to node_inode cache.
+ */
+void f2fs_cache_node_page(struct f2fs_sb_info *sbi, struct page *page,
+ nid_t nid, block_t blkaddr)
+{
+ struct address_space *mapping = sbi->node_inode->i_mapping;
+ struct page *npage;
+ struct node_info ni;
+
+ get_node_info(sbi, nid, &ni);
+
+ if (ni.blk_addr != blkaddr)
+ return;
+
+ npage = grab_cache_page(mapping, nid);
+ if (!npage)
+ return;
+
+ if (PageUptodate(npage)) {
+ f2fs_put_page(npage, 1);
+ return;
+ }
+
+ memcpy(page_address(npage), page_address(page), PAGE_CACHE_SIZE);
+
+ SetPageUptodate(npage);
+ f2fs_put_page(npage, 1);
+
+ return;
+}
+
int restore_node_summary(struct f2fs_sb_info *sbi,
unsigned int segno, struct f2fs_summary_block *sum)
{
struct f2fs_node *rn;
struct f2fs_summary *sum_entry;
struct page *page, *tmp;
- block_t addr;
+ block_t addr, blkaddr;
int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
int i, last_offset, nrpages, err = 0;
LIST_HEAD(page_list);
@@ -1624,6 +1657,7 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
if (err)
return err;

+ blkaddr = addr;
list_for_each_entry_safe(page, tmp, &page_list, lru) {

lock_page(page);
@@ -1633,6 +1667,8 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
sum_entry->version = 0;
sum_entry->ofs_in_node = 0;
sum_entry++;
+ f2fs_cache_node_page(sbi, page,
+ le32_to_cpu(rn->footer.nid), blkaddr);
} else {
err = -EIO;
}
@@ -1640,6 +1676,7 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
list_del(&page->lru);
unlock_page(page);
__free_pages(page, 0);
+ blkaddr++;
}
}
return err;
--
1.7.9.5

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