[PATCH v2 1/6] ext4: move the calculation of wbc->nr_to_write to mpage_folio_done()

[Zhang Yi <yi.zhang@huaweicloud.com>]

From: Zhang Yi <yi.zhang@huawei.com>

mpage_folio_done() should be a more appropriate place than
mpage_submit_folio() for updating the wbc->nr_to_write after we have
submitted a fully mapped folio. Preparing to make mpage_submit_folio()
allows to submit partially mapped folio that is still under processing.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/inode.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index be9a4cba35fd..3a086fee7989 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2024,7 +2024,10 @@ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 
 static void mpage_folio_done(struct mpage_da_data *mpd, struct folio *folio)
 {
-	mpd->first_page += folio_nr_pages(folio);
+	unsigned long nr_pages = folio_nr_pages(folio);
+
+	mpd->first_page += nr_pages;
+	mpd->wbc->nr_to_write -= nr_pages;
 	folio_unlock(folio);
 }
 
@@ -2055,8 +2058,6 @@ static int mpage_submit_folio(struct mpage_da_data *mpd, struct folio *folio)
 	    !ext4_verity_in_progress(mpd->inode))
 		len = size & (len - 1);
 	err = ext4_bio_write_folio(&mpd->io_submit, folio, len);
-	if (!err)
-		mpd->wbc->nr_to_write -= folio_nr_pages(folio);
 
 	return err;
 }
-- 
2.46.1