f2fs: fix dirty page accounting when redirty

We should de-account dirty counters for page when redirty in ->writepage().

Wu Fengguang described in 'commit 971767caf632190f77a40b4011c19948232eed75':
"writeback: fix dirtied pages accounting on redirty
De-account the accumulative dirty counters on page redirty.

Page redirties (very common in ext4) will introduce mismatch between
counters (a) and (b)

a) NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied
b) NR_WRITTEN, BDI_WRITTEN

This will introduce systematic errors in balanced_rate and result in
dirty page position errors (ie. the dirty pages are no longer balanced
around the global/bdi setpoints)."

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Chao Yu 2014-02-28 10:12:05 +08:00 committed by Jaegeuk Kim
parent 695fd1ed3b
commit 9cf3c3898a
3 changed files with 3 additions and 0 deletions

View file

@ -178,6 +178,7 @@ static int f2fs_write_meta_page(struct page *page,
redirty_out:
dec_page_count(sbi, F2FS_DIRTY_META);
wbc->pages_skipped++;
account_page_redirty(page);
set_page_dirty(page);
return AOP_WRITEPAGE_ACTIVATE;
}

View file

@ -839,6 +839,7 @@ static int f2fs_write_data_page(struct page *page,
redirty_out:
wbc->pages_skipped++;
account_page_redirty(page);
set_page_dirty(page);
return AOP_WRITEPAGE_ACTIVATE;
}

View file

@ -1193,6 +1193,7 @@ static int f2fs_write_node_page(struct page *page,
redirty_out:
dec_page_count(sbi, F2FS_DIRTY_NODES);
wbc->pages_skipped++;
account_page_redirty(page);
set_page_dirty(page);
return AOP_WRITEPAGE_ACTIVATE;
}