Re: [f2fs-dev] [PATCH 4/6] f2fs: avoid multiple node page writes due to inline_data

From: Jaegeuk Kim
Date: Tue Jan 26 2016 - 13:48:31 EST


Hi Chao,

On Tue, Jan 26, 2016 at 01:41:05PM +0800, Chao Yu wrote:
> Hi Jaegeuk,
>
> > -----Original Message-----
> > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx]
> > Sent: Tuesday, January 26, 2016 6:05 AM
> > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx;
> > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> > Cc: Jaegeuk Kim
> > Subject: [f2fs-dev] [PATCH 4/6] f2fs: avoid multiple node page writes due to inline_data
> >
> > The sceanrio is:
> > 1. create fully node blocks
> > 2. flush node blocks
> > 3. write inline_data for all the node blocks again
> > 4. flush node blocks redundantly
> >
> > So, this patch tries to flush inline_data when flushing node blocks.
> >
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> > fs/f2fs/data.c | 1 +
> > fs/f2fs/inline.c | 2 ++
> > fs/f2fs/node.c | 39 +++++++++++++++++++++++++++++++++++++++
> > fs/f2fs/node.h | 15 +++++++++++++++
> > 4 files changed, 57 insertions(+)
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 89a37ba..260c0eb 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -1463,6 +1463,7 @@ restart:
> > if (pos + len <= MAX_INLINE_DATA) {
> > read_inline_data(page, ipage);
> > set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
> > + set_inline_node(ipage);
> > sync_inode_page(&dn);
> > } else {
> > err = f2fs_convert_inline_page(&dn, page);
> > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
> > index 8df13e5..fc4d298 100644
> > --- a/fs/f2fs/inline.c
> > +++ b/fs/f2fs/inline.c
> > @@ -159,6 +159,7 @@ no_update:
> >
> > /* clear inline data and flag after data writeback */
> > truncate_inline_inode(dn->inode_page, 0);
> > + clear_inline_node(dn->inode_page);
> > clear_out:
> > stat_dec_inline_inode(dn->inode);
> > f2fs_clear_inline_inode(dn->inode);
> > @@ -233,6 +234,7 @@ int f2fs_write_inline_data(struct inode *inode, struct page *page)
> > set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
> >
> > sync_inode_page(&dn);
> > + clear_inline_node(dn.inode_page);
> > f2fs_put_dnode(&dn);
> > return 0;
> > }
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 23b800d..94a6755 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1154,6 +1154,37 @@ void sync_inode_page(struct dnode_of_data *dn)
> > dn->node_changed = ret ? true: false;
> > }
> >
> > +static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
> > +{
> > + struct inode *inode;
> > + struct page *page;
> > +
> > + /* should flush inline_data before evict_inode */
> > + inode = ilookup(sbi->sb, ino);
> > + if (!inode)
> > + return;
> > +
> > + page = pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0);
> > + if (!page)
> > + goto iput_out;
> > +
> > + if (!PageUptodate(page))
> > + goto page_out;
> > +
> > + if (!PageDirty(page))
> > + goto page_out;
> > +
> > + if (!clear_page_dirty_for_io(page))
> > + goto page_out;
> > +
> > + if (!f2fs_write_inline_data(inode, page))
>
> better to redirty the page when fail except -EAGAIN?

Agreed.

>
> > + inode_dec_dirty_pages(inode);
> > +page_out:
> > + f2fs_put_page(page, 1);
> > +iput_out:
> > + iput(inode);
> > +}
> > +
> > int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
> > struct writeback_control *wbc)
> > {
> > @@ -1221,6 +1252,14 @@ continue_unlock:
> > goto continue_unlock;
> > }
> >
> > + /* flush inline_data */
> > + if (!ino && is_inline_node(page)) {
> > + clear_inline_node(page);
>
> Should clear after flushed inline data? otherwise if we failed to flush
> inline data, we will lose the change to flush it before node flush.

My intention was just letting it go and flush by ->writepage later.
So, the above set_page_dirty() would handle this, right?

Thanks,

>
> Thanks,
>
> > + unlock_page(page);
> > + flush_inline_data(sbi, ino_of_node(page));
> > + continue;
> > + }
> > +
> > if (!clear_page_dirty_for_io(page))
> > goto continue_unlock;
> >
> > diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
> > index 23bd992..1f4f9d4 100644
> > --- a/fs/f2fs/node.h
> > +++ b/fs/f2fs/node.h
> > @@ -379,6 +379,21 @@ static inline int is_node(struct page *page, int type)
> > #define is_fsync_dnode(page) is_node(page, FSYNC_BIT_SHIFT)
> > #define is_dent_dnode(page) is_node(page, DENT_BIT_SHIFT)
> >
> > +static inline int is_inline_node(struct page *page)
> > +{
> > + return PageChecked(page);
> > +}
> > +
> > +static inline void set_inline_node(struct page *page)
> > +{
> > + SetPageChecked(page);
> > +}
> > +
> > +static inline void clear_inline_node(struct page *page)
> > +{
> > + ClearPageChecked(page);
> > +}
> > +
> > static inline void set_cold_node(struct inode *inode, struct page *page)
> > {
> > struct f2fs_node *rn = F2FS_NODE(page);
> > --
> > 2.6.3
> >
> >
> > ------------------------------------------------------------------------------
> > Site24x7 APM Insight: Get Deep Visibility into Application Performance
> > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
> > Monitor end-to-end web transactions and take corrective actions now
> > Troubleshoot faster and improve end-user experience. Signup Now!
> > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel