1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Volker Sameske <sameske@de.ibm.com>
5 * Bugreports.to..: <Linux390@de.ibm.com>
6 * Copyright IBM Corp. 1999, 2012
7 */
8
9 #include <linux/buffer_head.h>
10 #include <linux/hdreg.h>
11 #include <linux/slab.h>
12 #include <asm/dasd.h>
13 #include <asm/ebcdic.h>
14 #include <linux/uaccess.h>
15 #include <asm/vtoc.h>
16 #include <linux/module.h>
17 #include <linux/dasd_mod.h>
18
19 #include "check.h"
20
21 union label_t {
22 struct vtoc_volume_label_cdl vol;
23 struct vtoc_volume_label_ldl lnx;
24 struct vtoc_cms_label cms;
25 };
26
27 /*
28 * compute the block number from a
29 * cyl-cyl-head-head structure
30 */
cchh2blk(struct vtoc_cchh * ptr,struct hd_geometry * geo)31 static sector_t cchh2blk(struct vtoc_cchh *ptr, struct hd_geometry *geo)
32 {
33 sector_t cyl;
34 __u16 head;
35
36 /* decode cylinder and heads for large volumes */
37 cyl = ptr->hh & 0xFFF0;
38 cyl <<= 12;
39 cyl |= ptr->cc;
40 head = ptr->hh & 0x000F;
41 return cyl * geo->heads * geo->sectors +
42 head * geo->sectors;
43 }
44
45 /*
46 * compute the block number from a
47 * cyl-cyl-head-head-block structure
48 */
cchhb2blk(struct vtoc_cchhb * ptr,struct hd_geometry * geo)49 static sector_t cchhb2blk(struct vtoc_cchhb *ptr, struct hd_geometry *geo)
50 {
51 sector_t cyl;
52 __u16 head;
53
54 /* decode cylinder and heads for large volumes */
55 cyl = ptr->hh & 0xFFF0;
56 cyl <<= 12;
57 cyl |= ptr->cc;
58 head = ptr->hh & 0x000F;
59 return cyl * geo->heads * geo->sectors +
60 head * geo->sectors +
61 ptr->b;
62 }
63
find_label(struct parsed_partitions * state,dasd_information2_t * info,struct hd_geometry * geo,int blocksize,sector_t * labelsect,char name[],char type[],union label_t * label)64 static int find_label(struct parsed_partitions *state,
65 dasd_information2_t *info,
66 struct hd_geometry *geo,
67 int blocksize,
68 sector_t *labelsect,
69 char name[],
70 char type[],
71 union label_t *label)
72 {
73 Sector sect;
74 unsigned char *data;
75 sector_t testsect[3];
76 unsigned char temp[5];
77 int found = 0;
78 int i, testcount;
79
80 /* There a three places where we may find a valid label:
81 * - on an ECKD disk it's block 2
82 * - on an FBA disk it's block 1
83 * - on an CMS formatted FBA disk it is sector 1, even if the block size
84 * is larger than 512 bytes (possible if the DIAG discipline is used)
85 * If we have a valid info structure, then we know exactly which case we
86 * have, otherwise we just search through all possebilities.
87 */
88 if (info) {
89 if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
90 (info->cu_type == 0x3880 && info->dev_type == 0x3370))
91 testsect[0] = info->label_block;
92 else
93 testsect[0] = info->label_block * (blocksize >> 9);
94 testcount = 1;
95 } else {
96 testsect[0] = 1;
97 testsect[1] = (blocksize >> 9);
98 testsect[2] = 2 * (blocksize >> 9);
99 testcount = 3;
100 }
101 for (i = 0; i < testcount; ++i) {
102 data = read_part_sector(state, testsect[i], §);
103 if (data == NULL)
104 continue;
105 memcpy(label, data, sizeof(*label));
106 memcpy(temp, data, 4);
107 temp[4] = 0;
108 EBCASC(temp, 4);
109 put_dev_sector(sect);
110 if (!strcmp(temp, "VOL1") ||
111 !strcmp(temp, "LNX1") ||
112 !strcmp(temp, "CMS1")) {
113 if (!strcmp(temp, "VOL1")) {
114 strncpy(type, label->vol.vollbl, 4);
115 strncpy(name, label->vol.volid, 6);
116 } else {
117 strncpy(type, label->lnx.vollbl, 4);
118 strncpy(name, label->lnx.volid, 6);
119 }
120 EBCASC(type, 4);
121 EBCASC(name, 6);
122 *labelsect = testsect[i];
123 found = 1;
124 break;
125 }
126 }
127 if (!found)
128 memset(label, 0, sizeof(*label));
129
130 return found;
131 }
132
find_vol1_partitions(struct parsed_partitions * state,struct hd_geometry * geo,int blocksize,char name[],union label_t * label)133 static int find_vol1_partitions(struct parsed_partitions *state,
134 struct hd_geometry *geo,
135 int blocksize,
136 char name[],
137 union label_t *label)
138 {
139 sector_t blk;
140 int counter;
141 char tmp[64];
142 Sector sect;
143 unsigned char *data;
144 loff_t offset, size;
145 struct vtoc_format1_label f1;
146 int secperblk;
147
148 snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
149 strlcat(state->pp_buf, tmp, PAGE_SIZE);
150 /*
151 * get start of VTOC from the disk label and then search for format1
152 * and format8 labels
153 */
154 secperblk = blocksize >> 9;
155 blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
156 counter = 0;
157 data = read_part_sector(state, blk * secperblk, §);
158 while (data != NULL) {
159 memcpy(&f1, data, sizeof(struct vtoc_format1_label));
160 put_dev_sector(sect);
161 /* skip FMT4 / FMT5 / FMT7 labels */
162 if (f1.DS1FMTID == _ascebc['4']
163 || f1.DS1FMTID == _ascebc['5']
164 || f1.DS1FMTID == _ascebc['7']
165 || f1.DS1FMTID == _ascebc['9']) {
166 blk++;
167 data = read_part_sector(state, blk * secperblk, §);
168 continue;
169 }
170 /* only FMT1 and 8 labels valid at this point */
171 if (f1.DS1FMTID != _ascebc['1'] &&
172 f1.DS1FMTID != _ascebc['8'])
173 break;
174 /* OK, we got valid partition data */
175 offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
176 size = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
177 offset + geo->sectors;
178 offset *= secperblk;
179 size *= secperblk;
180 if (counter >= state->limit)
181 break;
182 put_partition(state, counter + 1, offset, size);
183 counter++;
184 blk++;
185 data = read_part_sector(state, blk * secperblk, §);
186 }
187 strlcat(state->pp_buf, "\n", PAGE_SIZE);
188
189 if (!data)
190 return -1;
191
192 return 1;
193 }
194
find_lnx1_partitions(struct parsed_partitions * state,struct hd_geometry * geo,int blocksize,char name[],union label_t * label,sector_t labelsect,sector_t nr_sectors,dasd_information2_t * info)195 static int find_lnx1_partitions(struct parsed_partitions *state,
196 struct hd_geometry *geo,
197 int blocksize,
198 char name[],
199 union label_t *label,
200 sector_t labelsect,
201 sector_t nr_sectors,
202 dasd_information2_t *info)
203 {
204 loff_t offset, geo_size, size;
205 char tmp[64];
206 int secperblk;
207
208 snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
209 strlcat(state->pp_buf, tmp, PAGE_SIZE);
210 secperblk = blocksize >> 9;
211 if (label->lnx.ldl_version == 0xf2) {
212 size = label->lnx.formatted_blocks * secperblk;
213 } else {
214 /*
215 * Formated w/o large volume support. If the sanity check
216 * 'size based on geo == size based on nr_sectors' is true, then
217 * we can safely assume that we know the formatted size of
218 * the disk, otherwise we need additional information
219 * that we can only get from a real DASD device.
220 */
221 geo_size = geo->cylinders * geo->heads
222 * geo->sectors * secperblk;
223 size = nr_sectors;
224 if (size != geo_size) {
225 if (!info) {
226 strlcat(state->pp_buf, "\n", PAGE_SIZE);
227 return 1;
228 }
229 if (!strcmp(info->type, "ECKD"))
230 if (geo_size < size)
231 size = geo_size;
232 /* else keep size based on nr_sectors */
233 }
234 }
235 /* first and only partition starts in the first block after the label */
236 offset = labelsect + secperblk;
237 put_partition(state, 1, offset, size - offset);
238 strlcat(state->pp_buf, "\n", PAGE_SIZE);
239 return 1;
240 }
241
find_cms1_partitions(struct parsed_partitions * state,struct hd_geometry * geo,int blocksize,char name[],union label_t * label,sector_t labelsect)242 static int find_cms1_partitions(struct parsed_partitions *state,
243 struct hd_geometry *geo,
244 int blocksize,
245 char name[],
246 union label_t *label,
247 sector_t labelsect)
248 {
249 loff_t offset, size;
250 char tmp[64];
251 int secperblk;
252
253 /*
254 * VM style CMS1 labeled disk
255 */
256 blocksize = label->cms.block_size;
257 secperblk = blocksize >> 9;
258 if (label->cms.disk_offset != 0) {
259 snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
260 strlcat(state->pp_buf, tmp, PAGE_SIZE);
261 /* disk is reserved minidisk */
262 offset = label->cms.disk_offset * secperblk;
263 size = (label->cms.block_count - 1) * secperblk;
264 } else {
265 snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
266 strlcat(state->pp_buf, tmp, PAGE_SIZE);
267 /*
268 * Special case for FBA devices:
269 * If an FBA device is CMS formatted with blocksize > 512 byte
270 * and the DIAG discipline is used, then the CMS label is found
271 * in sector 1 instead of block 1. However, the partition is
272 * still supposed to start in block 2.
273 */
274 if (labelsect == 1)
275 offset = 2 * secperblk;
276 else
277 offset = labelsect + secperblk;
278 size = label->cms.block_count * secperblk;
279 }
280
281 put_partition(state, 1, offset, size-offset);
282 strlcat(state->pp_buf, "\n", PAGE_SIZE);
283 return 1;
284 }
285
286
287 /*
288 * This is the main function, called by check.c
289 */
ibm_partition(struct parsed_partitions * state)290 int ibm_partition(struct parsed_partitions *state)
291 {
292 int (*fn)(struct gendisk *disk, dasd_information2_t *info);
293 struct gendisk *disk = state->disk;
294 struct block_device *bdev = disk->part0;
295 int blocksize, res;
296 loff_t offset, size;
297 sector_t nr_sectors;
298 dasd_information2_t *info;
299 struct hd_geometry *geo;
300 char type[5] = {0,};
301 char name[7] = {0,};
302 sector_t labelsect;
303 union label_t *label;
304
305 res = 0;
306 if (!disk->fops->getgeo)
307 goto out_exit;
308 fn = symbol_get(dasd_biodasdinfo);
309 blocksize = bdev_logical_block_size(bdev);
310 if (blocksize <= 0)
311 goto out_symbol;
312 nr_sectors = bdev_nr_sectors(bdev);
313 if (nr_sectors == 0)
314 goto out_symbol;
315 info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
316 if (info == NULL)
317 goto out_symbol;
318 geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
319 if (geo == NULL)
320 goto out_nogeo;
321 label = kmalloc(sizeof(union label_t), GFP_KERNEL);
322 if (label == NULL)
323 goto out_nolab;
324 /* set start if not filled by getgeo function e.g. virtblk */
325 geo->start = get_start_sect(bdev);
326 if (disk->fops->getgeo(bdev, geo))
327 goto out_freeall;
328 if (!fn || fn(disk, info)) {
329 kfree(info);
330 info = NULL;
331 }
332
333 if (find_label(state, info, geo, blocksize, &labelsect, name, type,
334 label)) {
335 if (!strncmp(type, "VOL1", 4)) {
336 res = find_vol1_partitions(state, geo, blocksize, name,
337 label);
338 } else if (!strncmp(type, "LNX1", 4)) {
339 res = find_lnx1_partitions(state, geo, blocksize, name,
340 label, labelsect, nr_sectors,
341 info);
342 } else if (!strncmp(type, "CMS1", 4)) {
343 res = find_cms1_partitions(state, geo, blocksize, name,
344 label, labelsect);
345 }
346 } else if (info) {
347 /*
348 * ugly but needed for backward compatibility:
349 * If the block device is a DASD (i.e. BIODASDINFO2 works),
350 * then we claim it in any case, even though it has no valid
351 * label. If it has the LDL format, then we simply define a
352 * partition as if it had an LNX1 label.
353 */
354 res = 1;
355 if (info->format == DASD_FORMAT_LDL) {
356 strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
357 size = nr_sectors;
358 offset = (info->label_block + 1) * (blocksize >> 9);
359 put_partition(state, 1, offset, size-offset);
360 strlcat(state->pp_buf, "\n", PAGE_SIZE);
361 }
362 } else
363 res = 0;
364
365 out_freeall:
366 kfree(label);
367 out_nolab:
368 kfree(geo);
369 out_nogeo:
370 kfree(info);
371 out_symbol:
372 if (fn)
373 symbol_put(dasd_biodasdinfo);
374 out_exit:
375 return res;
376 }
377