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  
64  /* Volume Label Type/ID Length */
65  #define DASD_VOL_TYPE_LEN	4
66  #define DASD_VOL_ID_LEN		6
67  
68  /* Volume Label Types */
69  #define DASD_VOLLBL_TYPE_VOL1 0
70  #define DASD_VOLLBL_TYPE_LNX1 1
71  #define DASD_VOLLBL_TYPE_CMS1 2
72  
73  struct dasd_vollabel {
74  	char *type;
75  	int idx;
76  };
77  
78  static struct dasd_vollabel dasd_vollabels[] = {
79  	[DASD_VOLLBL_TYPE_VOL1] = {
80  		.type = "VOL1",
81  		.idx = DASD_VOLLBL_TYPE_VOL1,
82  	},
83  	[DASD_VOLLBL_TYPE_LNX1] = {
84  		.type = "LNX1",
85  		.idx = DASD_VOLLBL_TYPE_LNX1,
86  	},
87  	[DASD_VOLLBL_TYPE_CMS1] = {
88  		.type = "CMS1",
89  		.idx = DASD_VOLLBL_TYPE_CMS1,
90  	},
91  };
92  
get_label_by_type(const char * type)93  static int get_label_by_type(const char *type)
94  {
95  	int i;
96  
97  	for (i = 0; i < ARRAY_SIZE(dasd_vollabels); i++) {
98  		if (!memcmp(type, dasd_vollabels[i].type, DASD_VOL_TYPE_LEN))
99  			return dasd_vollabels[i].idx;
100  	}
101  
102  	return -1;
103  }
104  
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)105  static int find_label(struct parsed_partitions *state,
106  		      dasd_information2_t *info,
107  		      struct hd_geometry *geo,
108  		      int blocksize,
109  		      sector_t *labelsect,
110  		      char name[],
111  		      char type[],
112  		      union label_t *label)
113  {
114  	sector_t testsect[3];
115  	int i, testcount;
116  	Sector sect;
117  	void *data;
118  
119  	/* There a three places where we may find a valid label:
120  	 * - on an ECKD disk it's block 2
121  	 * - on an FBA disk it's block 1
122  	 * - on an CMS formatted FBA disk it is sector 1, even if the block size
123  	 *   is larger than 512 bytes (possible if the DIAG discipline is used)
124  	 * If we have a valid info structure, then we know exactly which case we
125  	 * have, otherwise we just search through all possebilities.
126  	 */
127  	if (info) {
128  		if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
129  		    (info->cu_type == 0x3880 && info->dev_type == 0x3370))
130  			testsect[0] = info->label_block;
131  		else
132  			testsect[0] = info->label_block * (blocksize >> 9);
133  		testcount = 1;
134  	} else {
135  		testsect[0] = 1;
136  		testsect[1] = (blocksize >> 9);
137  		testsect[2] = 2 * (blocksize >> 9);
138  		testcount = 3;
139  	}
140  	for (i = 0; i < testcount; ++i) {
141  		data = read_part_sector(state, testsect[i], &sect);
142  		if (data == NULL)
143  			continue;
144  		memcpy(label, data, sizeof(*label));
145  		memcpy(type, data, DASD_VOL_TYPE_LEN);
146  		EBCASC(type, DASD_VOL_TYPE_LEN);
147  		put_dev_sector(sect);
148  		switch (get_label_by_type(type)) {
149  		case DASD_VOLLBL_TYPE_VOL1:
150  			memcpy(name, label->vol.volid, DASD_VOL_ID_LEN);
151  			EBCASC(name, DASD_VOL_ID_LEN);
152  			*labelsect = testsect[i];
153  			return 1;
154  		case DASD_VOLLBL_TYPE_LNX1:
155  		case DASD_VOLLBL_TYPE_CMS1:
156  			memcpy(name, label->lnx.volid, DASD_VOL_ID_LEN);
157  			EBCASC(name, DASD_VOL_ID_LEN);
158  			*labelsect = testsect[i];
159  			return 1;
160  		default:
161  			break;
162  		}
163  	}
164  
165  	return 0;
166  }
167  
find_vol1_partitions(struct parsed_partitions * state,struct hd_geometry * geo,int blocksize,char name[],union label_t * label)168  static int find_vol1_partitions(struct parsed_partitions *state,
169  				struct hd_geometry *geo,
170  				int blocksize,
171  				char name[],
172  				union label_t *label)
173  {
174  	sector_t blk;
175  	int counter;
176  	char tmp[64];
177  	Sector sect;
178  	unsigned char *data;
179  	loff_t offset, size;
180  	struct vtoc_format1_label f1;
181  	int secperblk;
182  
183  	snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
184  	strlcat(state->pp_buf, tmp, PAGE_SIZE);
185  	/*
186  	 * get start of VTOC from the disk label and then search for format1
187  	 * and format8 labels
188  	 */
189  	secperblk = blocksize >> 9;
190  	blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
191  	counter = 0;
192  	data = read_part_sector(state, blk * secperblk, &sect);
193  	while (data != NULL) {
194  		memcpy(&f1, data, sizeof(struct vtoc_format1_label));
195  		put_dev_sector(sect);
196  		/* skip FMT4 / FMT5 / FMT7 labels */
197  		if (f1.DS1FMTID == _ascebc['4']
198  		    || f1.DS1FMTID == _ascebc['5']
199  		    || f1.DS1FMTID == _ascebc['7']
200  		    || f1.DS1FMTID == _ascebc['9']) {
201  			blk++;
202  			data = read_part_sector(state, blk * secperblk, &sect);
203  			continue;
204  		}
205  		/* only FMT1 and 8 labels valid at this point */
206  		if (f1.DS1FMTID != _ascebc['1'] &&
207  		    f1.DS1FMTID != _ascebc['8'])
208  			break;
209  		/* OK, we got valid partition data */
210  		offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
211  		size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
212  			offset + geo->sectors;
213  		offset *= secperblk;
214  		size *= secperblk;
215  		if (counter >= state->limit)
216  			break;
217  		put_partition(state, counter + 1, offset, size);
218  		counter++;
219  		blk++;
220  		data = read_part_sector(state, blk * secperblk, &sect);
221  	}
222  	strlcat(state->pp_buf, "\n", PAGE_SIZE);
223  
224  	if (!data)
225  		return -1;
226  
227  	return 1;
228  }
229  
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)230  static int find_lnx1_partitions(struct parsed_partitions *state,
231  				struct hd_geometry *geo,
232  				int blocksize,
233  				char name[],
234  				union label_t *label,
235  				sector_t labelsect,
236  				sector_t nr_sectors,
237  				dasd_information2_t *info)
238  {
239  	loff_t offset, geo_size, size;
240  	char tmp[64];
241  	int secperblk;
242  
243  	snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
244  	strlcat(state->pp_buf, tmp, PAGE_SIZE);
245  	secperblk = blocksize >> 9;
246  	if (label->lnx.ldl_version == 0xf2) {
247  		size = label->lnx.formatted_blocks * secperblk;
248  	} else {
249  		/*
250  		 * Formated w/o large volume support. If the sanity check
251  		 * 'size based on geo == size based on nr_sectors' is true, then
252  		 * we can safely assume that we know the formatted size of
253  		 * the disk, otherwise we need additional information
254  		 * that we can only get from a real DASD device.
255  		 */
256  		geo_size = geo->cylinders * geo->heads
257  			* geo->sectors * secperblk;
258  		size = nr_sectors;
259  		if (size != geo_size) {
260  			if (!info) {
261  				strlcat(state->pp_buf, "\n", PAGE_SIZE);
262  				return 1;
263  			}
264  			if (!strcmp(info->type, "ECKD"))
265  				if (geo_size < size)
266  					size = geo_size;
267  			/* else keep size based on nr_sectors */
268  		}
269  	}
270  	/* first and only partition starts in the first block after the label */
271  	offset = labelsect + secperblk;
272  	put_partition(state, 1, offset, size - offset);
273  	strlcat(state->pp_buf, "\n", PAGE_SIZE);
274  	return 1;
275  }
276  
find_cms1_partitions(struct parsed_partitions * state,struct hd_geometry * geo,int blocksize,char name[],union label_t * label,sector_t labelsect)277  static int find_cms1_partitions(struct parsed_partitions *state,
278  				struct hd_geometry *geo,
279  				int blocksize,
280  				char name[],
281  				union label_t *label,
282  				sector_t labelsect)
283  {
284  	loff_t offset, size;
285  	char tmp[64];
286  	int secperblk;
287  
288  	/*
289  	 * VM style CMS1 labeled disk
290  	 */
291  	blocksize = label->cms.block_size;
292  	secperblk = blocksize >> 9;
293  	if (label->cms.disk_offset != 0) {
294  		snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
295  		strlcat(state->pp_buf, tmp, PAGE_SIZE);
296  		/* disk is reserved minidisk */
297  		offset = label->cms.disk_offset * secperblk;
298  		size = (label->cms.block_count - 1) * secperblk;
299  	} else {
300  		snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
301  		strlcat(state->pp_buf, tmp, PAGE_SIZE);
302  		/*
303  		 * Special case for FBA devices:
304  		 * If an FBA device is CMS formatted with blocksize > 512 byte
305  		 * and the DIAG discipline is used, then the CMS label is found
306  		 * in sector 1 instead of block 1. However, the partition is
307  		 * still supposed to start in block 2.
308  		 */
309  		if (labelsect == 1)
310  			offset = 2 * secperblk;
311  		else
312  			offset = labelsect + secperblk;
313  		size = label->cms.block_count * secperblk;
314  	}
315  
316  	put_partition(state, 1, offset, size-offset);
317  	strlcat(state->pp_buf, "\n", PAGE_SIZE);
318  	return 1;
319  }
320  
321  
322  /*
323   * This is the main function, called by check.c
324   */
ibm_partition(struct parsed_partitions * state)325  int ibm_partition(struct parsed_partitions *state)
326  {
327  	int (*fn)(struct gendisk *disk, dasd_information2_t *info);
328  	struct gendisk *disk = state->disk;
329  	struct block_device *bdev = disk->part0;
330  	int blocksize, res;
331  	loff_t offset, size;
332  	sector_t nr_sectors;
333  	dasd_information2_t *info;
334  	struct hd_geometry *geo;
335  	char type[DASD_VOL_TYPE_LEN + 1] = "";
336  	char name[DASD_VOL_ID_LEN + 1] = "";
337  	sector_t labelsect;
338  	union label_t *label;
339  
340  	res = 0;
341  	if (!disk->fops->getgeo)
342  		goto out_exit;
343  	fn = symbol_get(dasd_biodasdinfo);
344  	blocksize = bdev_logical_block_size(bdev);
345  	if (blocksize <= 0)
346  		goto out_symbol;
347  	nr_sectors = bdev_nr_sectors(bdev);
348  	if (nr_sectors == 0)
349  		goto out_symbol;
350  	info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
351  	if (info == NULL)
352  		goto out_symbol;
353  	geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
354  	if (geo == NULL)
355  		goto out_nogeo;
356  	label = kmalloc(sizeof(union label_t), GFP_KERNEL);
357  	if (label == NULL)
358  		goto out_nolab;
359  	/* set start if not filled by getgeo function e.g. virtblk */
360  	geo->start = get_start_sect(bdev);
361  	if (disk->fops->getgeo(bdev, geo))
362  		goto out_freeall;
363  	if (!fn || fn(disk, info)) {
364  		kfree(info);
365  		info = NULL;
366  	}
367  
368  	if (find_label(state, info, geo, blocksize, &labelsect, name, type, label)) {
369  		switch (get_label_by_type(type)) {
370  		case DASD_VOLLBL_TYPE_VOL1:
371  			res = find_vol1_partitions(state, geo, blocksize, name,
372  						   label);
373  			break;
374  		case DASD_VOLLBL_TYPE_LNX1:
375  			res = find_lnx1_partitions(state, geo, blocksize, name,
376  						   label, labelsect, nr_sectors,
377  						   info);
378  			break;
379  		case DASD_VOLLBL_TYPE_CMS1:
380  			res = find_cms1_partitions(state, geo, blocksize, name,
381  						   label, labelsect);
382  			break;
383  		}
384  	} else if (info) {
385  		/*
386  		 * ugly but needed for backward compatibility:
387  		 * If the block device is a DASD (i.e. BIODASDINFO2 works),
388  		 * then we claim it in any case, even though it has no valid
389  		 * label. If it has the LDL format, then we simply define a
390  		 * partition as if it had an LNX1 label.
391  		 */
392  		res = 1;
393  		if (info->format == DASD_FORMAT_LDL) {
394  			strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
395  			size = nr_sectors;
396  			offset = (info->label_block + 1) * (blocksize >> 9);
397  			put_partition(state, 1, offset, size-offset);
398  			strlcat(state->pp_buf, "\n", PAGE_SIZE);
399  		}
400  	} else
401  		res = 0;
402  
403  out_freeall:
404  	kfree(label);
405  out_nolab:
406  	kfree(geo);
407  out_nogeo:
408  	kfree(info);
409  out_symbol:
410  	if (fn)
411  		symbol_put(dasd_biodasdinfo);
412  out_exit:
413  	return res;
414  }
415