Re: [PATCH] f2fs: reduce unncessary locking pages during read

From: Jaegeuk Kim
Date: Tue Mar 19 2013 - 03:05:23 EST


2013-03-19 (í), 13:54 +0900, Namjae Jeon:
> >
> > - err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
> > - if (err) {
> > - f2fs_put_page(page, 1);
> > - return ERR_PTR(err);
> > + if (PageUptodate(page)) {
> > + unlock_page(page);
> > + return page;
> > }
> > - unlock_page(page);
> Hi Jaegeuk.
> > +
> > + err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
> > + wait_on_page_locked(page);
> > + if (!PageUptodate(page))
> > + return ERR_PTR(-EIO);
> We don't need to release page before returning EIO ?

Good catch! :)

>
> > return page;
> > }
> >
> > @@ -241,9 +244,13 @@ struct page *get_lock_data_page(struct inode *inode,
> > pgoff_t index)
> > BUG_ON(dn.data_blkaddr == NULL_ADDR);
> >
> > err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
> > - if (err) {
> > - f2fs_put_page(page, 1);
> > + if (err)
> > return ERR_PTR(err);
> Here is also same. We don't need to release page in case of err ?

It's different.
The f2fs_readpage() releases the page if error is occurred.
Thanks,

>
> Thanks.
> > +
> > + lock_page(page);
> > + if (!PageUptodate(page)) {
> > + f2fs_put_page(page, 1);
> > + return ERR_PTR(-EIO);
> > }
> > return page;
> > }
> --
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--
Jaegeuk Kim
Samsung

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