[ceph-client:tls_logger 12/19] net/ceph/ceph_san_pagefrag.c:107: warning: Excess function parameter 'n' description in 'cephsan_pagefrag_get_ptr_from_tail'

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/ceph/ceph-client.git tls_logger
head:   75b56e556ea415e29a13a8b7e98d302fbbec4c01
commit: b756c73bb29c0acb3b2509081debd5dc20045242 [12/19] fixup buffer allocation
config: i386-buildonly-randconfig-001-20250318 (https://download.01.org/0day-ci/archive/20250318/202503181819.sMIZbyRn-lkp@intel.com/config)
compiler: clang version 20.1.0 (https://github.com/llvm/llvm-project 24a30daaa559829ad079f2ff7f73eb4e18095f88)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250318/202503181819.sMIZbyRn-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503181819.sMIZbyRn-lkp@intel.com/

All warnings (new ones prefixed by >>):

   net/ceph/ceph_san_pagefrag.c:14: warning: Function parameter or struct member 'pf' not described in 'cephsan_pagefrag_init'
   net/ceph/ceph_san_pagefrag.c:54: warning: Function parameter or struct member 'pf' not described in 'cephsan_pagefrag_alloc'
>> net/ceph/ceph_san_pagefrag.c:107: warning: Excess function parameter 'n' description in 'cephsan_pagefrag_get_ptr_from_tail'
   net/ceph/ceph_san_pagefrag.c:119: warning: Function parameter or struct member 'pf' not described in 'cephsan_pagefrag_free'
   net/ceph/ceph_san_pagefrag.c:130: warning: Function parameter or struct member 'pf' not described in 'cephsan_pagefrag_deinit'
>> net/ceph/ceph_san_pagefrag.c:147: warning: Function parameter or struct member 'pf' not described in 'cephsan_pagefrag_reset'


vim +107 net/ceph/ceph_san_pagefrag.c

     5	
     6	/**
     7	 * cephsan_pagefrag_init - Initialize the pagefrag allocator.
     8	 *
     9	 * Allocates a 4MB contiguous buffer and resets head and tail pointers.
    10	 *
    11	 * Return: 0 on success, negative error code on failure.
    12	 */
    13	int cephsan_pagefrag_init(struct cephsan_pagefrag *pf)
  > 14	{
    15	    pf->pages = alloc_pages(GFP_KERNEL, get_order(CEPHSAN_PAGEFRAG_SIZE));
    16	    if (!pf->pages)
    17	        return -ENOMEM;
    18	
    19	    pf->buffer = page_address(pf->pages);
    20	    pf->head = 0;
    21	    pf->tail = 0;
    22	    return 0;
    23	}
    24	EXPORT_SYMBOL(cephsan_pagefrag_init);
    25	
    26	/**
    27	 * cephsan_pagefrag_init_with_buffer - Initialize pagefrag with an existing buffer
    28	 * @pf: pagefrag allocator to initialize
    29	 * @buffer: pre-allocated buffer to use
    30	 * @size: size of the buffer
    31	 *
    32	 * Return: 0 on success
    33	 */
    34	int cephsan_pagefrag_init_with_buffer(struct cephsan_pagefrag *pf, void *buffer, size_t size)
    35	{
    36	    pf->pages = NULL; /* No pages allocated, using provided buffer */
    37	    pf->buffer = buffer;
    38	    pf->head = 0;
    39	    pf->tail = 0;
    40	    return 0;
    41	}
    42	EXPORT_SYMBOL(cephsan_pagefrag_init_with_buffer);
    43	
    44	/**
    45	 * cephsan_pagefrag_alloc - Allocate bytes from the pagefrag buffer.
    46	 * @n: number of bytes to allocate.
    47	 *
    48	 * Allocates @n bytes if there is sufficient free space in the buffer.
    49	 * Advances the head pointer by @n bytes (wrapping around if needed).
    50	 *
    51	 * Return: pointer to the allocated memory, or NULL if not enough space.
    52	 */
    53	u64 cephsan_pagefrag_alloc(struct cephsan_pagefrag *pf, unsigned int n)
    54	{
    55	    /* Case 1: tail > head */
    56	    if (pf->tail > pf->head) {
    57	        if (pf->tail - pf->head > n) {
    58	            unsigned int prev_head = pf->head;
    59	            pf->head += n;
    60	            return ((u64)n << 32) | prev_head;
    61	        } else {
    62	            return 0;
    63	        }
    64	    }
    65	    /* Case 2: tail <= head */
    66	    if (pf->head + n <= CEPHSAN_PAGEFRAG_SIZE) {
    67	        /* Normal allocation */
    68	        unsigned int prev_head = pf->head;
    69	        pf->head += n;
    70	        return ((u64)n << 32) | prev_head;
    71	    } else {
    72	        /* Need to wrap around */
    73	        if (n < pf->tail) {
    74	            pf->head = n;
    75	            n += CEPHSAN_PAGEFRAG_SIZE - pf->head;
    76	            return ((u64)n << 32) | 0;
    77	        } else {
    78	            return 0;
    79	        }
    80	    }
    81	    pr_err("impossible: Not enough space in pagefrag buffer\n");
    82	    return 0;
    83	}
    84	EXPORT_SYMBOL(cephsan_pagefrag_alloc);
    85	
    86	/**
    87	 * cephsan_pagefrag_get_ptr - Get buffer pointer from pagefrag allocation result
    88	 * @pf: pagefrag allocator
    89	 * @val: return value from cephsan_pagefrag_alloc
    90	 *
    91	 * Return: pointer to allocated buffer region
    92	 */
    93	void *cephsan_pagefrag_get_ptr(struct cephsan_pagefrag *pf, u64 val)
    94	{
    95	    return pf->buffer + (val & 0xFFFFFFFF);
    96	}
    97	EXPORT_SYMBOL(cephsan_pagefrag_get_ptr);
    98	
    99	/**
   100	 * cephsan_pagefrag_get_ptr_from_tail - Get buffer pointer from pagefrag tail
   101	 * @pf: pagefrag allocator
   102	 * @n: number of bytes to get pointer from
   103	 *
   104	 * Returns pointer to the buffer region at the tail pointer minus @n bytes.
   105	 */
   106	void *cephsan_pagefrag_get_ptr_from_tail(struct cephsan_pagefrag *pf)
 > 107	{
   108	    return pf->buffer + pf->tail;
   109	}
   110	EXPORT_SYMBOL(cephsan_pagefrag_get_ptr_from_tail);
   111	
   112	/**
   113	 * cephsan_pagefrag_free - Free bytes in the pagefrag allocator.
   114	 * @n: number of bytes to free.
   115	 *
   116	 * Advances the tail pointer by @n bytes (wrapping around if needed).
   117	 */
   118	void cephsan_pagefrag_free(struct cephsan_pagefrag *pf, unsigned int n)
   119	{
   120	    pf->tail = (pf->tail + n) & (CEPHSAN_PAGEFRAG_SIZE - 1);
   121	}
   122	EXPORT_SYMBOL(cephsan_pagefrag_free);
   123	
   124	/**
   125	 * cephsan_pagefrag_deinit - Deinitialize the pagefrag allocator.
   126	 *
   127	 * Frees the allocated buffer and resets the head and tail pointers.
   128	 */
   129	void cephsan_pagefrag_deinit(struct cephsan_pagefrag *pf)
   130	{
   131	    if (pf->pages) {
   132	        free_pages((unsigned long)pf->pages, get_order(CEPHSAN_PAGEFRAG_SIZE));
   133	        pf->pages = NULL;
   134	    }
   135	    /* Don't free buffer if it was provided externally */
   136	    pf->buffer = NULL;
   137	    pf->head = pf->tail = 0;
   138	}
   139	EXPORT_SYMBOL(cephsan_pagefrag_deinit);
   140	
   141	/**
   142	 * cephsan_pagefrag_reset - Reset the pagefrag allocator.
   143	 *
   144	 * Resets the head and tail pointers to the beginning of the buffer.
   145	 */
   146	void cephsan_pagefrag_reset(struct cephsan_pagefrag *pf)
 > 147	{

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