[RFC PATCH v2 05/25] ext4: make ext4_map_blocks() distinguish delalloc only extent

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

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

Add a new map flag EXT4_MAP_DELAYED to indicate the mapping range is a
delayed allocated only (not unwritten) one, and making
ext4_map_blocks() can distinguish it, no longer mixing it with holes.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/ext4.h    | 4 +++-
 fs/ext4/extents.c | 5 +++--
 fs/ext4/inode.c   | 2 ++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a5d784872303..55195909d32f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -252,8 +252,10 @@ struct ext4_allocation_request {
 #define EXT4_MAP_MAPPED		BIT(BH_Mapped)
 #define EXT4_MAP_UNWRITTEN	BIT(BH_Unwritten)
 #define EXT4_MAP_BOUNDARY	BIT(BH_Boundary)
+#define EXT4_MAP_DELAYED	BIT(BH_Delay)
 #define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
-				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
+				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
+				 EXT4_MAP_DELAYED)
 
 struct ext4_map_blocks {
 	ext4_fsblk_t m_pblk;
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 0892d0568013..fc69f13cf510 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4073,9 +4073,10 @@ static void ext4_ext_determine_hole(struct inode *inode,
 	} else if (in_range(map->m_lblk, es.es_lblk, es.es_len)) {
 		/*
 		 * Straddle the beginning of the queried range, it's no
-		 * longer a hole, adjust the length to the delayed extent's
-		 * after map->m_lblk.
+		 * longer a hole, mark it is a delalloc and adjust the
+		 * length to the delayed extent's after map->m_lblk.
 		 */
+		map->m_flags |= EXT4_MAP_DELAYED;
 		len = es.es_lblk + es.es_len - map->m_lblk;
 		goto out;
 	} else {
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1b5e6409f958..c141bf6d8db2 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -515,6 +515,8 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 			map->m_len = retval;
 		} else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
 			map->m_pblk = 0;
+			map->m_flags |= ext4_es_is_delayed(&es) ?
+					EXT4_MAP_DELAYED : 0;
 			retval = es.es_len - (map->m_lblk - es.es_lblk);
 			if (retval > map->m_len)
 				retval = map->m_len;
-- 
2.39.2