linux-ext4 - [PATCH 3/3] gfs2: Convert stuffed_readpage() to stuffed_read

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Date:   Tue,  7 Nov 2023 21:26:42 +0000
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-ext4@...r.kernel.org, gfs2@...ts.linux.dev,
        linux-fsdevel@...r.kernel.org, linux-xfs@...r.kernel.org,
        "Darrick J . Wong" <djwong@...nel.org>,
        linux-erofs@...ts.ozlabs.org, "Theodore Ts'o" <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Andreas Gruenbacher <agruenba@...hat.com>
Subject: [PATCH 3/3] gfs2: Convert stuffed_readpage() to stuffed_read_folio()

Use folio_fill_tail() to implement the unstuffing and folio_end_read()
to simultaneously mark the folio uptodate and unlock it.  Unifies a
couple of code paths.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 fs/gfs2/aops.c | 37 +++++++++++++++++--------------------
 1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 9611bfceda4b..ba8742dc91f8 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -403,18 +403,18 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
 }
 
 /**
- * stuffed_readpage - Fill in a Linux folio with stuffed file data
+ * stuffed_read_folio - Fill in a Linux folio with stuffed file data
  * @ip: the inode
  * @folio: the folio
  *
  * Returns: errno
  */
-static int stuffed_readpage(struct gfs2_inode *ip, struct folio *folio)
+static int stuffed_read_folio(struct gfs2_inode *ip, struct folio *folio)
 {
-	struct buffer_head *dibh;
-	size_t i_size = i_size_read(&ip->i_inode);
-	void *data;
-	int error;
+	struct buffer_head *dibh = NULL;
+	size_t dsize = i_size_read(&ip->i_inode);
+	void *from = NULL;
+	int error = 0;
 
 	/*
 	 * Due to the order of unstuffing files and ->fault(), we can be
@@ -422,22 +422,20 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct folio *folio)
 	 * so we need to supply one here. It doesn't happen often.
 	 */
 	if (unlikely(folio->index)) {
-		folio_zero_range(folio, 0, folio_size(folio));
-		folio_mark_uptodate(folio);
-		return 0;
+		dsize = 0;
+	} else {
+		error = gfs2_meta_inode_buffer(ip, &dibh);
+		if (error)
+			goto out;
+		from = dibh->b_data + sizeof(struct gfs2_dinode);
 	}
 
-	error = gfs2_meta_inode_buffer(ip, &dibh);
-	if (error)
-		return error;
-
-	data = dibh->b_data + sizeof(struct gfs2_dinode);
-	memcpy_to_folio(folio, 0, data, i_size);
-	folio_zero_range(folio, i_size, folio_size(folio) - i_size);
+	folio_fill_tail(folio, 0, from, dsize);
 	brelse(dibh);
-	folio_mark_uptodate(folio);
+out:
+	folio_end_read(folio, error == 0);
 
-	return 0;
+	return error;
 }
 
 /**
@@ -456,8 +454,7 @@ static int gfs2_read_folio(struct file *file, struct folio *folio)
 	    (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
 		error = iomap_read_folio(folio, &gfs2_iomap_ops);
 	} else if (gfs2_is_stuffed(ip)) {
-		error = stuffed_readpage(ip, folio);
-		folio_unlock(folio);
+		error = stuffed_read_folio(ip, folio);
 	} else {
 		error = mpage_read_folio(folio, gfs2_block_map);
 	}
-- 
2.42.0