Re: [PATCH v3 5/5] f2fs: Optimize f2fs_truncate_data_blocks_range()

[yi sun]

Kindly ping.
I think there are no problems with the first few patches, but the
current patch may still have room for improvement. Do you have any
good suggestions?

On Mon, Nov 4, 2024 at 11:46 AM Yi Sun <yi.sun@xxxxxxxxxx> wrote:
>
> Function f2fs_invalidate_blocks() can process continuous
> blocks at a time, so f2fs_truncate_data_blocks_range() is
> optimized to use the new functionality of
> f2fs_invalidate_blocks().
>
> Signed-off-by: Yi Sun <yi.sun@xxxxxxxxxx>
> ---
>  fs/f2fs/file.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 68 insertions(+), 4 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 9366e7fc7c39..d20cc5f36d4c 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -612,6 +612,15 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
>         return finish_preallocate_blocks(inode);
>  }
>
> +static bool check_curr_block_is_consecutive(struct f2fs_sb_info *sbi,
> +                                       block_t curr, block_t end)
> +{
> +       if (curr - end == 1 || curr == end)
> +               return true;
> +       else
> +               return false;
> +}
> +
>  void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
>  {
>         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
> @@ -621,8 +630,27 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
>         int cluster_index = 0, valid_blocks = 0;
>         int cluster_size = F2FS_I(dn->inode)->i_cluster_size;
>         bool released = !atomic_read(&F2FS_I(dn->inode)->i_compr_blocks);
> +       /*
> +        * Temporary record location.
> +        * When the current  @blkaddr and @blkaddr_end can be processed
> +        * together, update the value of @blkaddr_end.
> +        * When it is detected that current @blkaddr is not continues with
> +        * @blkaddr_end, it is necessary to process continues blocks
> +        * range [blkaddr_start, blkaddr_end].
> +        */
> +       block_t blkaddr_start, blkaddr_end;
> +       /*.
> +        * To avoid processing various invalid data blocks.
> +        * Because @blkaddr_start and @blkaddr_end may be assigned
> +        * NULL_ADDR or invalid data blocks, @last_valid is used to
> +        * record this situation.
> +        */
> +       bool last_valid = false;
> +       /* Process the last @blkaddr separately? */
> +       bool last_one = true;
>
>         addr = get_dnode_addr(dn->inode, dn->node_page) + ofs;
> +       blkaddr_start = blkaddr_end = le32_to_cpu(*addr);
>
>         /* Assumption: truncation starts with cluster */
>         for (; count > 0; count--, addr++, dn->ofs_in_node++, cluster_index++) {
> @@ -638,24 +666,60 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
>                 }
>
>                 if (blkaddr == NULL_ADDR)
> -                       continue;
> +                       goto next;
>
>                 f2fs_set_data_blkaddr(dn, NULL_ADDR);
>
>                 if (__is_valid_data_blkaddr(blkaddr)) {
>                         if (time_to_inject(sbi, FAULT_BLKADDR_CONSISTENCE))
> -                               continue;
> +                               goto next;
>                         if (!f2fs_is_valid_blkaddr_raw(sbi, blkaddr,
>                                                 DATA_GENERIC_ENHANCE))
> -                               continue;
> +                               goto next;
>                         if (compressed_cluster)
>                                 valid_blocks++;
>                 }
>
> -               f2fs_invalidate_blocks(sbi, blkaddr, 1);
> +
> +               if (check_curr_block_is_consecutive(sbi, blkaddr, blkaddr_end)) {
> +                       /*
> +                        * The current block @blkaddr is continuous with
> +                        * @blkaddr_end, so @blkaddr_end is updated.
> +                        * And the f2fs_invalidate_blocks() is skipped
> +                        * until @blkaddr that cannot be processed
> +                        * together is encountered.
> +                        */
> +                       blkaddr_end = blkaddr;
> +                       if (count == 1)
> +                               last_one = false;
> +                       else
> +                               goto skip_invalid;
> +               }
> +
> +               f2fs_invalidate_blocks(sbi, blkaddr_start,
> +                                       blkaddr_end - blkaddr_start + 1);
> +               blkaddr_start = blkaddr_end = blkaddr;
> +
> +               if (count == 1 && last_one)
> +                       f2fs_invalidate_blocks(sbi, blkaddr, 1);
> +
> +skip_invalid:
> +               last_valid = true;
>
>                 if (!released || blkaddr != COMPRESS_ADDR)
>                         nr_free++;
> +
> +               continue;
> +
> +next:
> +               /* If consecutive blocks have been recorded, we need to process them. */
> +               if (last_valid == true)
> +                       f2fs_invalidate_blocks(sbi, blkaddr_start,
> +                                       blkaddr_end - blkaddr_start + 1);
> +
> +               blkaddr_start = blkaddr_end = le32_to_cpu(*(addr + 1));
> +               last_valid = false;
> +
>         }
>
>         if (compressed_cluster)
> --
> 2.25.1
>