to the disk, the stale data in the second half will be exposed once the cached extent entry is gone. Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting an unwritten extent before submitting I/O, and make ext4_split_convert_extents() to zero out the entire extent range to zero for this case, and also mark the extent in the extent status tree for consistency. Fixes: b8a8684502a0 ("ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate") Signed-off-by: Zhang Yi Reviewed-by: Ojaswin Mujoo Reviewed-by: Baokun Li Cc: stable@kernel.org Message-ID: <20251129103247.686136-4-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o [ different function signatures ] Signed-off-by: Sasha Levin --- fs/ext4/extents.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 1aad4ae0e7ae4..dfc365b021094 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3705,11 +3705,15 @@ static int ext4_split_convert_extents(handle_t *handle, /* Convert to unwritten */ if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { split_flag |= EXT4_EXT_DATA_VALID1; - /* Convert to initialized */ - } else if (flags & EXT4_GET_BLOCKS_CONVERT) { + /* Split the existing unwritten extent */ + } else if (flags & (EXT4_GET_BLOCKS_UNWRIT_EXT | + EXT4_GET_BLOCKS_CONVERT)) { split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; - split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); + split_flag |= EXT4_EXT_MARK_UNWRIT2; + /* Convert to initialized */ + if (flags & EXT4_GET_BLOCKS_CONVERT) + split_flag |= EXT4_EXT_DATA_VALID2; } flags |= EXT4_GET_BLOCKS_PRE_IO; return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); @@ -3874,7 +3878,7 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, /* get_block() before submitting IO, split the extent */ if (flags & EXT4_GET_BLOCKS_PRE_IO) { ret = ext4_split_convert_extents(handle, inode, map, ppath, - flags | EXT4_GET_BLOCKS_CONVERT); + flags); if (ret < 0) { err = ret; goto out2; -- 2.51.0[PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/OSasha Levin undefinedstable@vger.kernel.org undefined undefined undefined undefined undefined undefined¯l†“