lustre/obdclass/integrity.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2018, DataDirect Networks Storage.
  24  * Author: Li Xi.
  25  *
  26  * General data integrity functions
  27  */
  28 #include <linux/blkdev.h>
  29 #include <linux/crc-t10dif.h>
  30 #include <asm/checksum.h>
  31 #include <obd_class.h>
  32 #include <obd_cksum.h>
  33
  34 #if IS_ENABLED(CONFIG_CRC_T10DIF)
  35 __u16 obd_dif_crc_fn(void *data, unsigned int len)
  36 {
  37         return cpu_to_be16(crc_t10dif(data, len));
  38 }
  39 EXPORT_SYMBOL(obd_dif_crc_fn);
  40
  41 __u16 obd_dif_ip_fn(void *data, unsigned int len)
  42 {
  43         return ip_compute_csum(data, len);
  44 }
  45 EXPORT_SYMBOL(obd_dif_ip_fn);
  46
  47 int obd_page_dif_generate_buffer(const char *obd_name, struct page *page,
  48                                  __u32 offset, __u32 length,
  49                                  __u16 *guard_start, int guard_number,
  50                                  int *used_number, int sector_size,
  51                                  obd_dif_csum_fn *fn)
  52 {
  53         unsigned int i;
  54         char *data_buf;
  55         __u16 *guard_buf = guard_start;
  56         unsigned int data_size;
  57         int used = 0;
  58
  59         data_buf = kmap(page) + offset;
  60         for (i = 0; i < length; i += sector_size) {
  61                 if (used >= guard_number) {
  62                         CERROR("%s: unexpected used guard number of DIF %u/%u, "
  63                                "data length %u, sector size %u: rc = %d\n",
  64                                obd_name, used, guard_number, length,
  65                                sector_size, -E2BIG);
  66                         return -E2BIG;
  67                 }
  68                 data_size = length - i;
  69                 if (data_size > sector_size)
  70                         data_size = sector_size;
  71                 *guard_buf = fn(data_buf, data_size);
  72                 guard_buf++;
  73                 data_buf += data_size;
  74                 used++;
  75         }
  76         kunmap(page);
  77         *used_number = used;
  78
  79         return 0;
  80 }
  81 EXPORT_SYMBOL(obd_page_dif_generate_buffer);
  82
  83 static int __obd_t10_performance_test(const char *obd_name,
  84                                       enum cksum_types cksum_type,
  85                                       struct page *data_page,
  86                                       int repeat_number)
  87 {
  88         unsigned char cfs_alg = cksum_obd2cfs(OBD_CKSUM_T10_TOP);
  89         struct ahash_request *req;
  90         obd_dif_csum_fn *fn = NULL;
  91         unsigned int bufsize;
  92         unsigned char *buffer;
  93         struct page *__page;
  94         __u16 *guard_start;
  95         int guard_number;
  96         int used_number = 0;
  97         int sector_size = 0;
  98         __u32 cksum;
  99         int rc = 0;
 100         int rc2;
 101         int used;
 102         int i;
 103
 104         obd_t10_cksum2dif(cksum_type, &fn, &sector_size);
 105         if (!fn)
 106                 return -EINVAL;
 107
 108         __page = alloc_page(GFP_KERNEL);
 109         if (__page == NULL)
 110                 return -ENOMEM;
 111
 112         req = cfs_crypto_hash_init(cfs_alg, NULL, 0);
 113         if (IS_ERR(req)) {
 114                 rc = PTR_ERR(req);
 115                 CERROR("%s: unable to initialize checksum hash %s: rc = %d\n",
 116                        obd_name, cfs_crypto_hash_name(cfs_alg), rc);
 117                 GOTO(out, rc);
 118         }
 119
 120         buffer = kmap(__page);
 121         guard_start = (__u16 *)buffer;
 122         guard_number = PAGE_SIZE / sizeof(*guard_start);
 123         for (i = 0; i < repeat_number; i++) {
 124                 /*
 125                  * The left guard number should be able to hold checksums of a
 126                  * whole page
 127                  */
 128                 rc = obd_page_dif_generate_buffer(obd_name, data_page, 0,
 129                                                   PAGE_SIZE,
 130                                                   guard_start + used_number,
 131                                                   guard_number - used_number,
 132                                                   &used, sector_size, fn);
 133                 if (rc)
 134                         break;
 135
 136                 used_number += used;
 137                 if (used_number == guard_number) {
 138                         cfs_crypto_hash_update_page(req, __page, 0,
 139                                 used_number * sizeof(*guard_start));
 140                         used_number = 0;
 141                 }
 142         }
 143         kunmap(__page);
 144         if (rc)
 145                 GOTO(out_final, rc);
 146
 147         if (used_number != 0)
 148                 cfs_crypto_hash_update_page(req, __page, 0,
 149                         used_number * sizeof(*guard_start));
 150
 151         bufsize = sizeof(cksum);
 152 out_final:
 153         rc2 = cfs_crypto_hash_final(req, (unsigned char *)&cksum, &bufsize);
 154         rc = rc ? rc : rc2;
 155 out:
 156         __free_page(__page);
 157
 158         return rc;
 159 }
 160
 161 /**
 162  *  Array of T10PI checksum algorithm speed in MByte per second
 163  */
 164 static int obd_t10_cksum_speeds[OBD_T10_CKSUM_MAX];
 165
 166 static enum obd_t10_cksum_type
 167 obd_t10_cksum2type(enum cksum_types cksum_type)
 168 {
 169         switch (cksum_type) {
 170         case OBD_CKSUM_T10IP512:
 171                 return OBD_T10_CKSUM_IP512;
 172         case OBD_CKSUM_T10IP4K:
 173                 return OBD_T10_CKSUM_IP4K;
 174         case OBD_CKSUM_T10CRC512:
 175                 return OBD_T10_CKSUM_CRC512;
 176         case OBD_CKSUM_T10CRC4K:
 177                 return OBD_T10_CKSUM_CRC4K;
 178         default:
 179                 return OBD_T10_CKSUM_UNKNOWN;
 180         }
 181 }
 182
 183 static const char *obd_t10_cksum_name(enum obd_t10_cksum_type index)
 184 {
 185         DECLARE_CKSUM_NAME;
 186
 187         /* Need to skip "crc32", "adler", "crc32c", "reserved" */
 188         return cksum_name[3 + index];
 189 }
 190
 191 /**
 192  * Compute the speed of specified T10PI checksum type
 193  *
 194  * Run a speed test on the given T10PI checksum on buffer using a 1MB buffer
 195  * size. This is a reasonable buffer size for Lustre RPCs, even if the actual
 196  * RPC size is larger or smaller.
 197  *
 198  * The speed is stored internally in the obd_t10_cksum_speeds[] array, and
 199  * is available through the obd_t10_cksum_speed() function.
 200  *
 201  * This function needs to stay the same as cfs_crypto_performance_test() so
 202  * that the speeds are comparable. And this function should reflect the real
 203  * cost of the checksum calculation.
 204  *
 205  * \param[in] obd_name          name of the OBD device
 206  * \param[in] cksum_type        checksum type (OBD_CKSUM_T10*)
 207  */
 208 static void obd_t10_performance_test(const char *obd_name,
 209                                      enum cksum_types cksum_type)
 210 {
 211         enum obd_t10_cksum_type index = obd_t10_cksum2type(cksum_type);
 212         const int buf_len = max(PAGE_SIZE, 1048576UL);
 213         unsigned long bcount;
 214         unsigned long start;
 215         unsigned long end;
 216         struct page *page;
 217         int rc = 0;
 218         void *buf;
 219
 220         page = alloc_page(GFP_KERNEL);
 221         if (page == NULL) {
 222                 rc = -ENOMEM;
 223                 goto out;
 224         }
 225
 226         buf = kmap(page);
 227         memset(buf, 0xAD, PAGE_SIZE);
 228         kunmap(page);
 229
 230         for (start = jiffies, end = start + msecs_to_jiffies(MSEC_PER_SEC / 4),
 231              bcount = 0; time_before(jiffies, end) && rc == 0; bcount++) {
 232                 rc = __obd_t10_performance_test(obd_name, cksum_type, page,
 233                                                 buf_len / PAGE_SIZE);
 234                 if (rc)
 235                         break;
 236         }
 237         end = jiffies;
 238         __free_page(page);
 239 out:
 240         if (rc) {
 241                 obd_t10_cksum_speeds[index] = rc;
 242                 CDEBUG(D_INFO, "%s: T10 checksum algorithm %s test error: "
 243                        "rc = %d\n", obd_name, obd_t10_cksum_name(index), rc);
 244         } else {
 245                 unsigned long tmp;
 246
 247                 tmp = ((bcount * buf_len / jiffies_to_msecs(end - start)) *
 248                        1000) / (1024 * 1024);
 249                 obd_t10_cksum_speeds[index] = (int)tmp;
 250                 CDEBUG(D_CONFIG, "%s: T10 checksum algorithm %s speed = %d "
 251                        "MB/s\n", obd_name, obd_t10_cksum_name(index),
 252                        obd_t10_cksum_speeds[index]);
 253         }
 254 }
 255 #endif /* CONFIG_CRC_T10DIF */
 256
 257 int obd_t10_cksum_speed(const char *obd_name,
 258                         enum cksum_types cksum_type)
 259 {
 260 #if IS_ENABLED(CONFIG_CRC_T10DIF)
 261         enum obd_t10_cksum_type index = obd_t10_cksum2type(cksum_type);
 262
 263         if (unlikely(obd_t10_cksum_speeds[index] == 0)) {
 264                 static DEFINE_MUTEX(obd_t10_cksum_speed_mutex);
 265
 266                 mutex_lock(&obd_t10_cksum_speed_mutex);
 267                 if (obd_t10_cksum_speeds[index] == 0)
 268                         obd_t10_performance_test(obd_name, cksum_type);
 269                 mutex_unlock(&obd_t10_cksum_speed_mutex);
 270         }
 271
 272         return obd_t10_cksum_speeds[index];
 273 #else /* !CONFIG_CRC_T10DIF */
 274         return 0;
 275 #endif /* !CONFIG_CRC_T10DIF */
 276 }
 277 EXPORT_SYMBOL(obd_t10_cksum_speed);