From: Zhang Yi <yi.zhang@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
fs/ext4/ext4.h | 4 +++-
fs/ext4/extents.c | 7 +++++--
fs/ext4/inode.c | 2 ++
3 files changed, 10 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 e0b7e48c4c67..6b64319a7df8 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4076,8 +4076,11 @@ static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode,
/*
* The delalloc extent containing lblk, it must have been
* added after ext4_map_blocks() checked the extent status
- * tree, adjust the length to the delalloc extent's after
- * lblk.
+ * tree so we are not holding i_rwsem and delalloc info is
+ * only stabilized by i_data_sem we are going to release
+ * soon. Don't modify the extent status tree and report
+ * extent as a hole, just adjust the length to the delalloc
+ * extent's after lblk.
*/
len = es.es_lblk + es.es_len - lblk;
return len;
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
