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SubjectRe: [PATCH v3 1/3] lib: bitmap: introduce bitmap_print_to_buf
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在 2021/6/3 17:50, Andy Shevchenko 写道:
> On Thu, Jun 03, 2021 at 05:22:40PM +0800, Tian Tao wrote:
>> New API bitmap_print_to_buf() with bin_attribute to avoid maskp
>> exceeding PAGE_SIZE. bitmap_print_to_pagebuf() is a special case
>> of bitmap_print_to_buf(), so in bitmap_print_to_pagebuf() call
>> bitmap_print_to_buf().
> ...
>
>> /**
>> + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string
>> + * @list: indicates whether the bitmap must be list
>> + * @buf: the kernel space buffer to read to
>> + * @maskp: pointer to bitmap to convert
>> + * @nmaskbits: size of bitmap, in bits
>> + * @off: offset in data buffer below
>> + * @count: the maximum number of bytes to print
>> + *
>> + * The role of bitmap_print_to_buf() and bitmap_print_to_pagebuf() is
>> + * the same, the difference is that buf of bitmap_print_to_buf()
>> + * can be more than one pagesize.
>> + */
>> +int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp,
>> + int nmaskbits, loff_t off, size_t count)
>> +{
>> + const char *fmt = list ? "%*pbl\n" : "%*pb\n";
>> + ssize_t size;
>> + void *data;
>> +
>> + if (off == LLONG_MAX && count == PAGE_SIZE - offset_in_page(buf))
>> + return scnprintf(buf, count, fmt, nmaskbits, maskp);
>> +
>> + data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1);
> Are you sure you have put parameters in the correct order?

yes, I already test it.

ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
                                const void *from, size_t available)

>
>> + kfree(data);
>> +
>> + return size;
>> +}
> I guess you have to provide the test case(s).
>

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