ext4: don't set EXTENT_STATUS_DELAYED on allocated blocks

Currently, we release delayed allocation reservation when removing
delayed extent from extent status tree (which also happens when
overwriting one extent with another one). When we allocated unwritten
extent under some delayed allocated extent, we don't need the
reservation anymore and hence we don't need to preserve the
EXT4_MAP_DELAYED status bit. Allocating the new extent blocks will
properly release the reservation.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240813123452.2824659-4-yi.zhang@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/extents_status.c

@@ -869,14 +869,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 		return;
 
 	BUG_ON(end < lblk);
-
-	if ((status & EXTENT_STATUS_DELAYED) &&
-	    (status & EXTENT_STATUS_WRITTEN)) {
-		ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
-				" delayed and written which can potentially "
-				" cause data loss.", lblk, len);
-		WARN_ON(1);
-	}
+	WARN_ON_ONCE(status & EXTENT_STATUS_DELAYED);
 
 	newes.es_lblk = lblk;
 	newes.es_len = len;

fs/ext4/inode.c

@@ -558,12 +558,6 @@ static int ext4_map_create_blocks(handle_t *handle, struct inode *inode,
 
 	status = map->m_flags & EXT4_MAP_UNWRITTEN ?
 			EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
-	if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
-	    !(status & EXTENT_STATUS_WRITTEN) &&
-	    ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
-			       map->m_lblk + map->m_len - 1))
-		status |= EXTENT_STATUS_DELAYED;
-
 	ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
 			      map->m_pblk, status);
 
@@ -682,11 +676,6 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 
 		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
 				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
-		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
-		    !(status & EXTENT_STATUS_WRITTEN) &&
-		    ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
-				       map->m_lblk + map->m_len - 1))
-			status |= EXTENT_STATUS_DELAYED;
 		ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
 				      map->m_pblk, status);
 	}