Re: [PATCH v4 04/12] ext4: use pre-allocated es in __es_insert_extent()

Jan Kara
2023-05-03T14:28:44Z

On Mon 24-04-23 11:38:38, Baokun Li wrote:
> Pass a extent_status pointer prealloc to __es_insert_extent(). If the
> pointer is non-null, it is used directly when a new extent_status is
> needed to avoid memory allocation failures.
>
> Suggested-by: Jan Kara <jack@suse.cz>
> 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 | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
> index 18665394392f..a6a62a744e83 100644
> --- a/fs/ext4/extents_status.c
> +++ b/fs/ext4/extents_status.c
> @@ -144,7 +144,8 @@
> static struct kmem_cache *ext4_es_cachep;
> static struct kmem_cache *ext4_pending_cachep;
>
> -static int __es_insert_extent(struct inode *inode, struct extent_status *newes);
> +static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
> + struct extent_status *prealloc);
> static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
> ext4_lblk_t end, int *reserved);
> static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
> @@ -768,7 +769,8 @@ static inline void ext4_es_insert_extent_check(struct inode *inode,
> }
> #endif
>
> -static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
> +static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
> + struct extent_status *prealloc)
> {
> struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
> struct rb_node **p = &tree->root.rb_node;
> @@ -808,7 +810,10 @@ static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
> }
> }
>
> - es = __es_alloc_extent(false);
> + if (prealloc)
> + es = prealloc;
> + else
> + es = __es_alloc_extent(false);
> if (!es)
> return -ENOMEM;
> ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
> @@ -868,7 +873,7 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
> if (err != 0)
> goto error;
> retry:
> - err = __es_insert_extent(inode, &newes);
> + err = __es_insert_extent(inode, &newes, NULL);
> if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
> 128, EXT4_I(inode)))
> goto retry;
> @@ -918,7 +923,7 @@ void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
>
> es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
> if (!es || es->es_lblk > end)
> - __es_insert_extent(inode, &newes);
> + __es_insert_extent(inode, &newes, NULL);
> write_unlock(&EXT4_I(inode)->i_es_lock);
> }
>
> @@ -1366,7 +1371,7 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
> orig_es.es_len - len2;
> ext4_es_store_pblock_status(&newes, block,
> ext4_es_status(&orig_es));
> - err = __es_insert_extent(inode, &newes);
> + err = __es_insert_extent(inode, &newes, NULL);
> if (err) {
> es->es_lblk = orig_es.es_lblk;
> es->es_len = orig_es.es_len;
> @@ -2020,7 +2025,7 @@ int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
> if (err != 0)
> goto error;
> retry:
> - err = __es_insert_extent(inode, &newes);
> + err = __es_insert_extent(inode, &newes, NULL);
> if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
> 128, EXT4_I(inode)))
> goto retry;
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR