Re: [PATCH v2 02/15] ceph: add BLOG deserialization support

On Mon, 6 Jul 2026 at 22:38, Alex Markuze <[email protected]> wrote:
>
> Add blog_des.c implementing the binary record deserialization engine
> used by the debugfs read paths.  Supports %d, %i, %u, %o, %x, %X,
> %s, %p, %c, and length modifiers (l, ll, h, hh, z).
>
> Signed-off-by: Alex Markuze <[email protected]>
> ---
>  fs/ceph/blog_des.c | 332 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 332 insertions(+)
>  create mode 100644 fs/ceph/blog_des.c
>
> diff --git a/fs/ceph/blog_des.c b/fs/ceph/blog_des.c
> new file mode 100644
> index 000000000000..e84ca3fa156c
> --- /dev/null
> +++ b/fs/ceph/blog_des.c
> @@ -0,0 +1,332 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Binary Logging Deserialization
> + */
> +

[......]

> +               case 'p': {
> +                       void *ptr;
> +
> +                       if (buf_ptr + sizeof(void *) > buf_end)
> +                               return -EBADMSG;
> +
> +                       ptr = (void *)(unsigned long)get_unaligned((unsigned long *)buf_ptr);
> +                       buf_ptr += sizeof(void *);
> +
> +                       /*
> +                        * Skip kernel %p sub-specifiers (U, I, d, D, etc.).
> +                        * bout/boutc do not support %p extensions; call sites
> +                        * must pre-format them with snprintf and pass %s.
> +                        */
> +                       while (fmt_ptr[1] && isalpha(fmt_ptr[1]))

s/isalpha()/isalnum()/ ?

Because %p can also include numbers, likes:

sprintf(tbuf, "%pI4", n->key);  <<== For IPv4 address

> +                               fmt_ptr++;
> +
> +                       ret = snprintf(out_ptr, remaining, "%p", ptr);
[......]