Re: [PATCH v4 03/12] ext4: factor out __es_alloc_extent() and __es_free_extent()

Jan Kara
2023-05-03T14:28:18Z

On Mon 24-04-23 11:38:37, Baokun Li wrote:
> Factor out __es_alloc_extent() and __es_free_extent(), which only allocate
> and free extent_status in these two helpers.
>
> The ext4_es_alloc_extent() function is split into __es_alloc_extent()
> and ext4_es_init_extent(). In __es_alloc_extent() we allocate memory using
> GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO if the memory allocation cannot
> fail, otherwise we use GFP_ATOMIC. and the ext4_es_init_extent() is used to
> initialize extent_status and update related variables after a successful
> allocation.
>
> This is to prepare for the use of pre-allocated extent_status later.
>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>

Looks good. Feel free to add:

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

Honza

> ---
> fs/ext4/extents_status.c | 30 +++++++++++++++++++-----------
> 1 file changed, 19 insertions(+), 11 deletions(-)
>
> diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
> index 573723b23d19..18665394392f 100644
> --- a/fs/ext4/extents_status.c
> +++ b/fs/ext4/extents_status.c
> @@ -461,14 +461,17 @@ static inline bool ext4_es_must_keep(struct extent_status *es)
> return false;
> }
>
> -static struct extent_status *
> -ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
> - ext4_fsblk_t pblk)
> +static inline struct extent_status *__es_alloc_extent(bool nofail)
> +{
> + if (!nofail)
> + return kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
> +
> + return kmem_cache_zalloc(ext4_es_cachep, GFP_KERNEL | __GFP_NOFAIL);
> +}
> +
> +static void ext4_es_init_extent(struct inode *inode, struct extent_status *es,
> + ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
> {
> - struct extent_status *es;
> - es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
> - if (es == NULL)
> - return NULL;
> es->es_lblk = lblk;
> es->es_len = len;
> es->es_pblk = pblk;
> @@ -483,8 +486,11 @@ ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
>
> EXT4_I(inode)->i_es_all_nr++;
> percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
> +}
>
> - return es;
> +static inline void __es_free_extent(struct extent_status *es)
> +{
> + kmem_cache_free(ext4_es_cachep, es);
> }
>
> static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
> @@ -501,7 +507,7 @@ static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
> s_es_stats.es_stats_shk_cnt);
> }
>
> - kmem_cache_free(ext4_es_cachep, es);
> + __es_free_extent(es);
> }
>
> /*
> @@ -802,10 +808,12 @@ static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
> }
> }
>
> - es = ext4_es_alloc_extent(inode, newes->es_lblk, newes->es_len,
> - newes->es_pblk);
> + es = __es_alloc_extent(false);
> if (!es)
> return -ENOMEM;
> + ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
> + newes->es_pblk);
> +
> rb_link_node(&es->rb_node, parent, p);
> rb_insert_color(&es->rb_node, &tree->root);
>
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR