[PATCH v2 3/9] ext4: refactor out ext4_generic_attr_show()

Baokun Li
2024-02-27T09:10:10Z

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>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
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 2b1c529b7fdf..7f455b5f22c0 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