Commit 874eaba9 authored by Zhang Yi's avatar Zhang Yi Committed by Theodore Ts'o
Browse files

ext4: make ext4_map_blocks() distinguish delalloc only extent 



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: default avatarZhang Yi <yi.zhang@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240127015825.1608160-6-yi.zhang@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 9f111822

fs/ext4/ext4.h

+3 −1
Original line number Diff line number Diff line
@@ -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;

fs/ext4/extents.c

+5 −2
Original line number Diff line number Diff line
@@ -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;

fs/ext4/inode.c

+2 −0
Original line number Diff line number Diff line
@@ -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;