Re: [PATCH] jfs: clear PAGECACHE_TAG_DIRTY for no-write pages

Fengguang Wu
2007-12-29T02:21:18Z

On Fri, Dec 28, 2007 at 10:53:14AM -0600, Dave Kleikamp wrote:

> ---
>
> diff -Nurp linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c linux/fs/jfs/jfs_metapage.c
> --- linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c 2007-12-28 10:28:33.000000000 -0600
> +++ linux/fs/jfs/jfs_metapage.c 2007-12-28 10:37:30.000000000 -0600
> @@ -360,6 +360,7 @@ static int metapage_writepage(struct pag
> struct metapage *mp;
> int redirty = 0;
> sector_t lblock;
> + int nr_underway = 0;
> sector_t pblock;
> sector_t next_block = 0;
> sector_t page_start;
> @@ -371,6 +372,7 @@ static int metapage_writepage(struct pag
> (PAGE_CACHE_SHIFT - inode->i_blkbits);
> BUG_ON(!PageLocked(page));
> BUG_ON(PageWriteback(page));

This line should be moved below:
> + set_page_writeback(page);

>
> for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
> mp = page_to_mp(page, offset);
> @@ -413,11 +415,10 @@ static int metapage_writepage(struct pag
> if (!bio->bi_size)
> goto dump_bio;
> submit_bio(WRITE, bio);
> + nr_underway++;
> bio = NULL;
> - } else {
> - set_page_writeback(page);
> + } else
> inc_io(page);
> - }
> xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
> pblock = metapage_get_blocks(inode, lblock, &xlen);
> if (!pblock) {
> @@ -449,12 +450,16 @@ static int metapage_writepage(struct pag
> goto dump_bio;
>
> submit_bio(WRITE, bio);
> + nr_underway++;
> }
> if (redirty)
> redirty_page_for_writepage(wbc, page);
+ else
+ set_page_writeback(page);
>
> unlock_page(page);
>
> + if (nr_underway == 0)
+ if (nr_underway == 0 && redirty == 0)

> + end_page_writeback(page);
> +
> return 0;
> add_failed:
> /* We should never reach here, since we're only adding one vec */

Otherwise looks pretty good.

Reviewed-by: Fengguang Wu <wfg@mail.ustc.edu.cn>