From c0329d0288dee6be26e5eca71fdc520c1c5e6acf Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Sat, 29 Nov 2025 18:32:40 +0800 Subject: [PATCH] ext4: cleanup zeroout in ext4_split_extent_at() zero_ex is a temporary variable used only for writing zeros and inserting extent status entry, it will not be directly inserted into the tree. Therefore, it can be assigned values from the target extent in various scenarios, eliminating the need to explicitly assign values to each variable individually. Signed-off-by: Zhang Yi Reviewed-by: Ojaswin Mujoo Reviewed-by: Jan Kara Reviewed-by: Baokun Li Message-ID: <20251129103247.686136-9-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 87 ++++++++++++++++++++--------------------------- 1 file changed, 36 insertions(+), 51 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 945995d68c4d3..2cfce2c012084 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3287,63 +3287,48 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle, ex = path[depth].p_ext; if (EXT4_EXT_MAY_ZEROOUT & split_flag) { - if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { - if (split_flag & EXT4_EXT_DATA_VALID1) { - err = ext4_ext_zeroout(inode, ex2); - zero_ex.ee_block = ex2->ee_block; - zero_ex.ee_len = cpu_to_le16( - ext4_ext_get_actual_len(ex2)); - ext4_ext_store_pblock(&zero_ex, - ext4_ext_pblock(ex2)); - } else { - err = ext4_ext_zeroout(inode, ex); - zero_ex.ee_block = ex->ee_block; - zero_ex.ee_len = cpu_to_le16( - ext4_ext_get_actual_len(ex)); - ext4_ext_store_pblock(&zero_ex, - ext4_ext_pblock(ex)); - } - } else { - err = ext4_ext_zeroout(inode, &orig_ex); - zero_ex.ee_block = orig_ex.ee_block; - zero_ex.ee_len = cpu_to_le16( - ext4_ext_get_actual_len(&orig_ex)); - ext4_ext_store_pblock(&zero_ex, - ext4_ext_pblock(&orig_ex)); - } + if (split_flag & EXT4_EXT_DATA_VALID1) + memcpy(&zero_ex, ex2, sizeof(zero_ex)); + else if (split_flag & EXT4_EXT_DATA_VALID2) + memcpy(&zero_ex, ex, sizeof(zero_ex)); + else + memcpy(&zero_ex, &orig_ex, sizeof(zero_ex)); + ext4_ext_mark_initialized(&zero_ex); - if (!err) { + err = ext4_ext_zeroout(inode, &zero_ex); + if (err) + goto fix_extent_len; + + /* + * The first half contains partially valid data, the splitting + * of this extent has not been completed, fix extent length + * and ext4_split_extent() split will the first half again. + */ + if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1) { /* - * The first half contains partially valid data, the - * splitting of this extent has not been completed, fix - * extent length and ext4_split_extent() split will the - * first half again. + * Drop extent cache to prevent stale unwritten + * extents remaining after zeroing out. */ - if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1) { - /* - * Drop extent cache to prevent stale unwritten - * extents remaining after zeroing out. - */ - ext4_es_remove_extent(inode, + ext4_es_remove_extent(inode, le32_to_cpu(zero_ex.ee_block), ext4_ext_get_actual_len(&zero_ex)); - goto fix_extent_len; - } - - /* update the extent length and mark as initialized */ - ex->ee_len = cpu_to_le16(ee_len); - ext4_ext_try_to_merge(handle, inode, path, ex); - err = ext4_ext_dirty(handle, inode, path + path->p_depth); - if (!err) - /* update extent status tree */ - ext4_zeroout_es(inode, &zero_ex); - /* If we failed at this point, we don't know in which - * state the extent tree exactly is so don't try to fix - * length of the original extent as it may do even more - * damage. - */ - goto out; + goto fix_extent_len; } + + /* update the extent length and mark as initialized */ + ex->ee_len = cpu_to_le16(ee_len); + ext4_ext_try_to_merge(handle, inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); + if (!err) + /* update extent status tree */ + ext4_zeroout_es(inode, &zero_ex); + /* + * If we failed at this point, we don't know in which + * state the extent tree exactly is so don't try to fix + * length of the original extent as it may do even more + * damage. + */ + goto out; } fix_extent_len: -- 2.47.3