linux-ext4 - [PATCH 1/4] ext4: remove useless code in ext4_map_create

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Message-ID: <20251027122303.1146352-1-yangerkun@huawei.com>
Date: Mon, 27 Oct 2025 20:23:00 +0800
From: Yang Erkun <yangerkun@...wei.com>
To: <linux-ext4@...r.kernel.org>, <tytso@....edu>, <adilger.kernel@...ger.ca>,
	<jack@...e.cz>
CC: <yi.zhang@...wei.com>, <libaokun1@...wei.com>, <yangerkun@...wei.com>,
	<yangerkun@...weicloud.com>
Subject: [PATCH 1/4] ext4: remove useless code in ext4_map_create_blocks

IO path with EXT4_GET_BLOCKS_PRE_IO means dio within i_size or
dioread_nolock buffer writeback, they all means we need a unwritten
extent(or this extent has already been initialized), and the split won't
zero the range we really write. So this check seems useless. Besides,
even if we repeatedly execute ext4_es_insert_extent, there won't
actually be any issues.

Signed-off-by: Yang Erkun <yangerkun@...wei.com>
---
 fs/ext4/inode.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e99306a8f47c..e8bac93ca668 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -583,7 +583,6 @@ static int ext4_map_query_blocks(handle_t *handle, struct inode *inode,
 static int ext4_map_create_blocks(handle_t *handle, struct inode *inode,
 				  struct ext4_map_blocks *map, int flags)
 {
-	struct extent_status es;
 	unsigned int status;
 	int err, retval = 0;
 
@@ -644,16 +643,6 @@ static int ext4_map_create_blocks(handle_t *handle, struct inode *inode,
 			return err;
 	}
 
-	/*
-	 * If the extent has been zeroed out, we don't need to update
-	 * extent status tree.
-	 */
-	if (flags & EXT4_GET_BLOCKS_PRE_IO &&
-	    ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
-		if (ext4_es_is_written(&es))
-			return retval;
-	}
-
 	status = map->m_flags & EXT4_MAP_UNWRITTEN ?
 			EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
 	ext4_es_insert_extent(inode, map->m_lblk, map->m_len, map->m_pblk,
-- 
2.39.2