linux-ext4 - [PATCH 4/7] ext4: Don't unlock page in ext4_bio_write

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Date:   Wed, 11 Jan 2023 16:43:28 +0100
From:   Jan Kara <jack@...e.cz>
To:     Ted Tso <tytso@....edu>
Cc:     <linux-ext4@...r.kernel.org>, Jan Kara <jack@...e.cz>
Subject: [PATCH 4/7] ext4: Don't unlock page in ext4_bio_write_page()

Do not unlock the written page in ext4_bio_write_page(). Instead leave
the page locked and unlock it in the callers. We'll need to keep the
page locked for data=journal writeback for a bit longer.

Signed-off-by: Jan Kara <jack@...e.cz>
---
 fs/ext4/inode.c   |  2 ++
 fs/ext4/page-io.c | 10 +++++-----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4c14aa1b9152..237880f0d406 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2076,6 +2076,7 @@ static int ext4_writepage(struct page *page,
 		return -ENOMEM;
 	}
 	ret = ext4_bio_write_page(&io_submit, page, len);
+	unlock_page(page);
 	ext4_io_submit(&io_submit);
 	/* Drop io_end reference we got from init */
 	ext4_put_io_end_defer(io_submit.io_end);
@@ -2110,6 +2111,7 @@ static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
 	else
 		len = PAGE_SIZE;
 	err = ext4_bio_write_page(&mpd->io_submit, page, len);
+	unlock_page(page);
 	if (!err)
 		mpd->wbc->nr_to_write--;
 	mpd->first_page++;
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index beaec6d81074..3bc7c7c5b99d 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -500,7 +500,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 
 	/* Nothing to submit? Just unlock the page... */
 	if (!nr_to_submit)
-		goto unlock;
+		return 0;
 
 	bh = head = page_buffers(page);
 
@@ -548,7 +548,8 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 				}
 				bh = bh->b_this_page;
 			} while (bh != head);
-			goto unlock;
+
+			return ret;
 		}
 	}
 
@@ -564,7 +565,6 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 		io_submit_add_bh(io, inode,
 				 bounce_page ? bounce_page : page, bh);
 	} while ((bh = bh->b_this_page) != head);
-unlock:
-	unlock_page(page);
-	return ret;
+
+	return 0;
 }
-- 
2.35.3