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Message-ID: <20240725120754.q6wfgluukul33vh3@quack3>
Date: Thu, 25 Jul 2024 14:07:54 +0200
From: Jan Kara <jack@...e.cz>
To: libaokun@...weicloud.com
Cc: linux-ext4@...r.kernel.org, tytso@....edu, adilger.kernel@...ger.ca,
jack@...e.cz, ritesh.list@...il.com, linux-kernel@...r.kernel.org,
yi.zhang@...wei.com, yangerkun@...wei.com,
Baokun Li <libaokun1@...wei.com>
Subject: Re: [PATCH 14/20] ext4: get rid of ppath in ext4_split_extent()
On Wed 10-07-24 12:06:48, libaokun@...weicloud.com wrote:
> From: Baokun Li <libaokun1@...wei.com>
>
> 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_extent(), the following is done here:
>
> * The 'allocated' is changed from passing a value to passing an address.
> * Its caller needs to update ppath if it uses ppath.
>
> No functional changes.
>
> Signed-off-by: Baokun Li <libaokun1@...wei.com>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@...e.cz>
Honza
> ---
> fs/ext4/extents.c | 97 ++++++++++++++++++++++++-----------------------
> 1 file changed, 50 insertions(+), 47 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 0bd068ed324f..2a4f6c89858c 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -3345,21 +3345,18 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
> * c> Splits in three extents: Somone is splitting in middle of the extent
> *
> */
> -static int ext4_split_extent(handle_t *handle,
> - struct inode *inode,
> - struct ext4_ext_path **ppath,
> - struct ext4_map_blocks *map,
> - int split_flag,
> - int flags)
> +static struct ext4_ext_path *ext4_split_extent(handle_t *handle,
> + struct inode *inode,
> + struct ext4_ext_path *path,
> + struct ext4_map_blocks *map,
> + int split_flag, int flags,
> + unsigned int *allocated)
> {
> - struct ext4_ext_path *path = *ppath;
> ext4_lblk_t ee_block;
> struct ext4_extent *ex;
> unsigned int ee_len, depth;
> - int err = 0;
> int unwritten;
> int split_flag1, flags1;
> - int allocated = map->m_len;
>
> depth = ext_depth(inode);
> ex = path[depth].p_ext;
> @@ -3377,33 +3374,25 @@ static int ext4_split_extent(handle_t *handle,
> split_flag1 |= EXT4_EXT_DATA_VALID1;
> path = ext4_split_extent_at(handle, inode, path,
> map->m_lblk + map->m_len, split_flag1, flags1);
> - if (IS_ERR(path)) {
> - err = PTR_ERR(path);
> - *ppath = NULL;
> - goto out;
> + if (IS_ERR(path))
> + return path;
> + /*
> + * Update path is required because previous ext4_split_extent_at
> + * may result in split of original leaf or extent zeroout.
> + */
> + path = ext4_find_extent(inode, map->m_lblk, path, flags);
> + if (IS_ERR(path))
> + return path;
> + depth = ext_depth(inode);
> + ex = path[depth].p_ext;
> + if (!ex) {
> + EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
> + (unsigned long) map->m_lblk);
> + ext4_free_ext_path(path);
> + return ERR_PTR(-EFSCORRUPTED);
> }
> - *ppath = path;
> - } else {
> - allocated = ee_len - (map->m_lblk - ee_block);
> - }
> - /*
> - * Update path is required because previous ext4_split_extent_at() may
> - * result in split of original leaf or extent zeroout.
> - */
> - path = ext4_find_extent(inode, map->m_lblk, path, flags);
> - if (IS_ERR(path)) {
> - *ppath = NULL;
> - return PTR_ERR(path);
> - }
> - *ppath = path;
> - depth = ext_depth(inode);
> - ex = path[depth].p_ext;
> - if (!ex) {
> - EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
> - (unsigned long) map->m_lblk);
> - return -EFSCORRUPTED;
> + unwritten = ext4_ext_is_unwritten(ex);
> }
> - unwritten = ext4_ext_is_unwritten(ex);
>
> if (map->m_lblk >= ee_block) {
> split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
> @@ -3414,17 +3403,18 @@ static int ext4_split_extent(handle_t *handle,
> }
> path = ext4_split_extent_at(handle, inode, path,
> map->m_lblk, split_flag1, flags);
> - if (IS_ERR(path)) {
> - err = PTR_ERR(path);
> - *ppath = NULL;
> - goto out;
> - }
> - *ppath = path;
> + if (IS_ERR(path))
> + return path;
> }
>
> + if (allocated) {
> + if (map->m_lblk + map->m_len > ee_block + ee_len)
> + *allocated = ee_len - (map->m_lblk - ee_block);
> + else
> + *allocated = map->m_len;
> + }
> ext4_ext_show_leaf(inode, path);
> -out:
> - return err ? err : allocated;
> + return path;
> }
>
> /*
> @@ -3669,10 +3659,15 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
> }
>
> fallback:
> - err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
> - flags);
> - if (err > 0)
> - err = 0;
> + path = ext4_split_extent(handle, inode, path, &split_map, split_flag,
> + flags, NULL);
> + if (IS_ERR(path)) {
> + err = PTR_ERR(path);
> + *ppath = NULL;
> + goto out;
> + }
> + err = 0;
> + *ppath = path;
> out:
> /* If we have gotten a failure, don't zero out status tree */
> if (!err) {
> @@ -3718,6 +3713,7 @@ static int ext4_split_convert_extents(handle_t *handle,
> 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);
> @@ -3745,7 +3741,14 @@ 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;
> - return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
> + 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;
> }
>
> static int ext4_convert_unwritten_extents_endio(handle_t *handle,
> --
> 2.39.2
>
--
Jan Kara <jack@...e.com>
SUSE Labs, CR
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