Re: [PATCH v5 09/10] ext4: make ext4_insert_delayed_block() insert multi-blocks

Jan Kara
2024-05-20T09:39:52Z

On Fri 17-05-24 20:40:04, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
>
> Rename ext4_insert_delayed_block() to ext4_insert_delayed_blocks(),
> pass length parameter to make it insert multiple delalloc blocks at a
> time. For non-bigalloc case, just reserve len blocks and insert delalloc
> extent. For bigalloc case, we can ensure that the clusters in the middle
> of a extent must be unallocated, we only need to check whether the start
> and end clusters are delayed/allocated. We should subtract the space for
> the start and/or end block(s) if they are allocated.
>
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/inode.c | 51 ++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 36 insertions(+), 15 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index eefedb7264c7..4febee4c833f 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1679,24 +1679,29 @@ static int ext4_clu_alloc_state(struct inode *inode, ext4_lblk_t lblk)
> }
>
> /*
> - * ext4_insert_delayed_block - adds a delayed block to the extents status
> - * tree, incrementing the reserved cluster/block
> - * count or making a pending reservation
> - * where needed
> + * ext4_insert_delayed_blocks - adds a multiple delayed blocks to the extents
> + * status tree, incrementing the reserved
> + * cluster/block count or making pending
> + * reservations where needed
> *
> * @inode - file containing the newly added block
> - * @lblk - logical block to be added
> + * @lblk - start logical block to be added
> + * @len - length of blocks to be added
> *
> * Returns 0 on success, negative error code on failure.
> */
> -static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
> +static int ext4_insert_delayed_blocks(struct inode *inode, ext4_lblk_t lblk,
> + ext4_lblk_t len)
> {
> struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> int ret;
> - bool allocated = false;
> + bool lclu_allocated = false;
> + bool end_allocated = false;
> + ext4_lblk_t resv_clu;
> + ext4_lblk_t end = lblk + len - 1;
>
> /*
> - * If the cluster containing lblk is shared with a delayed,
> + * If the cluster containing lblk or end is shared with a delayed,
> * written, or unwritten extent in a bigalloc file system, it's
> * already been accounted for and does not need to be reserved.
> * A pending reservation must be made for the cluster if it's
> @@ -1707,23 +1712,39 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
> * extents status tree doesn't get a match.
> */
> if (sbi->s_cluster_ratio == 1) {
> - ret = ext4_da_reserve_space(inode, 1);
> + ret = ext4_da_reserve_space(inode, len);
> if (ret != 0) /* ENOSPC */
> return ret;
> } else { /* bigalloc */
> + resv_clu = EXT4_B2C(sbi, end) - EXT4_B2C(sbi, lblk) + 1;
> +
> ret = ext4_clu_alloc_state(inode, lblk);
> if (ret < 0)
> return ret;
> - if (ret == 2)
> - allocated = true;
> - if (ret == 0) {
> - ret = ext4_da_reserve_space(inode, 1);
> + if (ret > 0) {
> + resv_clu--;
> + lclu_allocated = (ret == 2);
> + }
> +
> + if (EXT4_B2C(sbi, lblk) != EXT4_B2C(sbi, end)) {
> + ret = ext4_clu_alloc_state(inode, end);
> + if (ret < 0)
> + return ret;
> + if (ret > 0) {
> + resv_clu--;
> + end_allocated = (ret == 2);
> + }
> + }
> +
> + if (resv_clu) {
> + ret = ext4_da_reserve_space(inode, resv_clu);
> if (ret != 0) /* ENOSPC */
> return ret;
> }
> }
>
> - ext4_es_insert_delayed_extent(inode, lblk, 1, allocated, false);
> + ext4_es_insert_delayed_extent(inode, lblk, len, lclu_allocated,
> + end_allocated);
> return 0;
> }
>
> @@ -1828,7 +1849,7 @@ static int ext4_da_map_blocks(struct inode *inode, struct ext4_map_blocks *map,
> }
> }
>
> - retval = ext4_insert_delayed_block(inode, map->m_lblk);
> + retval = ext4_insert_delayed_blocks(inode, map->m_lblk, map->m_len);
> up_write(&EXT4_I(inode)->i_data_sem);
> if (retval)
> return retval;
> --
> 2.39.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR