Re: [PATCH 15/20] ext4: get rid of ppath in ext4_split_convert_extents()

From: Jan Kara
Date: Thu Jul 25 2024 - 08:12:40 EST


On Wed 10-07-24 12:06:49, libaokun@xxxxxxxxxxxxxxx wrote:
> From: Baokun Li <libaokun1@xxxxxxxxxx>
>
> The use of path and ppath is now very confusing, so to make the code more
> readable, pass path between functions uniformly, and get rid of ppath.
>
> To get rid of the ppath in ext4_split_convert_extents(), the following is
> done here:
>
> * Its caller needs to update ppath if it uses ppath.
>
> No functional changes.
>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza


> ---
> fs/ext4/extents.c | 65 ++++++++++++++++++++++++-----------------------
> 1 file changed, 33 insertions(+), 32 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 2a4f6c89858c..a41cbb8c4475 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -3699,21 +3699,21 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
> * being filled will be convert to initialized by the end_io callback function
> * via ext4_convert_unwritten_extents().
> *
> - * Returns the size of unwritten extent to be written on success.
> + * The size of unwritten extent to be written is passed to the caller via the
> + * allocated pointer. Return an extent path pointer on success, or an error
> + * pointer on failure.
> */
> -static int ext4_split_convert_extents(handle_t *handle,
> +static struct ext4_ext_path *ext4_split_convert_extents(handle_t *handle,
> struct inode *inode,
> struct ext4_map_blocks *map,
> - struct ext4_ext_path **ppath,
> - int flags)
> + struct ext4_ext_path *path,
> + int flags, unsigned int *allocated)
> {
> - struct ext4_ext_path *path = *ppath;
> ext4_lblk_t eof_block;
> ext4_lblk_t ee_block;
> struct ext4_extent *ex;
> unsigned int ee_len;
> int split_flag = 0, depth;
> - unsigned int allocated = 0;
>
> ext_debug(inode, "logical block %llu, max_blocks %u\n",
> (unsigned long long)map->m_lblk, map->m_len);
> @@ -3741,14 +3741,8 @@ static int ext4_split_convert_extents(handle_t *handle,
> split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
> }
> flags |= EXT4_GET_BLOCKS_PRE_IO;
> - path = ext4_split_extent(handle, inode, path, map, split_flag, flags,
> - &allocated);
> - if (IS_ERR(path)) {
> - *ppath = NULL;
> - return PTR_ERR(path);
> - }
> - *ppath = path;
> - return allocated;
> + return ext4_split_extent(handle, inode, path, map, split_flag, flags,
> + allocated);
> }
>
> static int ext4_convert_unwritten_extents_endio(handle_t *handle,
> @@ -3784,11 +3778,14 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
> inode->i_ino, (unsigned long long)ee_block, ee_len,
> (unsigned long long)map->m_lblk, map->m_len);
> #endif
> - err = ext4_split_convert_extents(handle, inode, map, ppath,
> - EXT4_GET_BLOCKS_CONVERT);
> - if (err < 0)
> - return err;
> - path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
> + path = ext4_split_convert_extents(handle, inode, map, path,
> + EXT4_GET_BLOCKS_CONVERT, NULL);
> + if (IS_ERR(path)) {
> + *ppath = NULL;
> + return PTR_ERR(path);
> + }
> +
> + path = ext4_find_extent(inode, map->m_lblk, path, 0);
> if (IS_ERR(path)) {
> *ppath = NULL;
> return PTR_ERR(path);
> @@ -3845,11 +3842,14 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
> (unsigned long long)ee_block, ee_len);
>
> if (ee_block != map->m_lblk || ee_len > map->m_len) {
> - err = ext4_split_convert_extents(handle, inode, map, ppath,
> - EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
> - if (err < 0)
> - return err;
> - path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
> + path = ext4_split_convert_extents(handle, inode, map, path,
> + EXT4_GET_BLOCKS_CONVERT_UNWRITTEN, NULL);
> + if (IS_ERR(path)) {
> + *ppath = NULL;
> + return PTR_ERR(path);
> + }
> +
> + path = ext4_find_extent(inode, map->m_lblk, path, 0);
> if (IS_ERR(path)) {
> *ppath = NULL;
> return PTR_ERR(path);
> @@ -3915,19 +3915,20 @@ 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);
> - if (ret < 0) {
> - err = ret;
> + *ppath = ext4_split_convert_extents(handle, inode, map, *ppath,
> + flags | EXT4_GET_BLOCKS_CONVERT, &allocated);
> + if (IS_ERR(*ppath)) {
> + err = PTR_ERR(*ppath);
> + *ppath = NULL;
> goto out2;
> }
> /*
> - * shouldn't get a 0 return when splitting an extent unless
> + * shouldn't get a 0 allocated when splitting an extent unless
> * m_len is 0 (bug) or extent has been corrupted
> */
> - if (unlikely(ret == 0)) {
> + if (unlikely(allocated == 0)) {
> EXT4_ERROR_INODE(inode,
> - "unexpected ret == 0, m_len = %u",
> + "unexpected allocated == 0, m_len = %u",
> map->m_len);
> err = -EFSCORRUPTED;
> goto out2;
> @@ -3988,9 +3989,9 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
> err = -EFSCORRUPTED;
> goto out2;
> }
> + allocated = ret;
>
> out:
> - allocated = ret;
> map->m_flags |= EXT4_MAP_NEW;
> map_out:
> map->m_flags |= EXT4_MAP_MAPPED;
> --
> 2.39.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR