Re: [PATCH 3/7] ext4: refactor out ext4_generic_attr_show()

Jan Kara
2024-02-13T16:44:04Z

On Fri 26-01-24 16:57:12, Baokun Li wrote:
> Refactor out the function ext4_generic_attr_show() to handle the reading
> of values of various common types, with no functional changes.
>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>

Looks good. Feel free to add:

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

Honza

> ---
> fs/ext4/sysfs.c | 74 +++++++++++++++++++++----------------------------
> 1 file changed, 32 insertions(+), 42 deletions(-)
>
> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
> index 834f9a0eb641..a5d657fa05cb 100644
> --- a/fs/ext4/sysfs.c
> +++ b/fs/ext4/sysfs.c
> @@ -366,13 +366,42 @@ static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
> #define print_tstamp(buf, es, tstamp) \
> __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
>
> +static ssize_t ext4_generic_attr_show(struct ext4_attr *a,
> + struct ext4_sb_info *sbi, char *buf)
> +{
> + void *ptr = calc_ptr(a, sbi);
> +
> + if (!ptr)
> + return 0;
> +
> + switch (a->attr_id) {
> + case attr_inode_readahead:
> + case attr_pointer_ui:
> + if (a->attr_ptr == ptr_ext4_super_block_offset)
> + return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr));
> + return sysfs_emit(buf, "%u\n", *((unsigned int *) ptr));
> + case attr_pointer_ul:
> + return sysfs_emit(buf, "%lu\n", *((unsigned long *) ptr));
> + case attr_pointer_u8:
> + return sysfs_emit(buf, "%u\n", *((unsigned char *) ptr));
> + case attr_pointer_u64:
> + if (a->attr_ptr == ptr_ext4_super_block_offset)
> + return sysfs_emit(buf, "%llu\n", le64_to_cpup(ptr));
> + return sysfs_emit(buf, "%llu\n", *((unsigned long long *) ptr));
> + case attr_pointer_string:
> + return sysfs_emit(buf, "%.*s\n", a->attr_size, (char *) ptr);
> + case attr_pointer_atomic:
> + return sysfs_emit(buf, "%d\n", atomic_read((atomic_t *) ptr));
> + }
> + return 0;
> +}
> +
> static ssize_t ext4_attr_show(struct kobject *kobj,
> struct attribute *attr, char *buf)
> {
> struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
> s_kobj);
> struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
> - void *ptr = calc_ptr(a, sbi);
>
> switch (a->attr_id) {
> case attr_delayed_allocation_blocks:
> @@ -391,45 +420,6 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
> return sysfs_emit(buf, "%llu\n",
> (unsigned long long)
> percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
> - case attr_inode_readahead:
> - case attr_pointer_ui:
> - if (!ptr)
> - return 0;
> - if (a->attr_ptr == ptr_ext4_super_block_offset)
> - return sysfs_emit(buf, "%u\n",
> - le32_to_cpup(ptr));
> - else
> - return sysfs_emit(buf, "%u\n",
> - *((unsigned int *) ptr));
> - case attr_pointer_ul:
> - if (!ptr)
> - return 0;
> - return sysfs_emit(buf, "%lu\n",
> - *((unsigned long *) ptr));
> - case attr_pointer_u8:
> - if (!ptr)
> - return 0;
> - return sysfs_emit(buf, "%u\n",
> - *((unsigned char *) ptr));
> - case attr_pointer_u64:
> - if (!ptr)
> - return 0;
> - if (a->attr_ptr == ptr_ext4_super_block_offset)
> - return sysfs_emit(buf, "%llu\n",
> - le64_to_cpup(ptr));
> - else
> - return sysfs_emit(buf, "%llu\n",
> - *((unsigned long long *) ptr));
> - case attr_pointer_string:
> - if (!ptr)
> - return 0;
> - return sysfs_emit(buf, "%.*s\n", a->attr_size,
> - (char *) ptr);
> - case attr_pointer_atomic:
> - if (!ptr)
> - return 0;
> - return sysfs_emit(buf, "%d\n",
> - atomic_read((atomic_t *) ptr));
> case attr_feature:
> return sysfs_emit(buf, "supported\n");
> case attr_first_error_time:
> @@ -438,9 +428,9 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
> return print_tstamp(buf, sbi->s_es, s_last_error_time);
> case attr_journal_task:
> return journal_task_show(sbi, buf);
> + default:
> + return ext4_generic_attr_show(a, sbi, buf);
> }
> -
> - return 0;
> }
>
> static ssize_t ext4_generic_attr_store(struct ext4_attr *a,
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR