multipath.rules: find_multipaths "smart" logic
[multipath-tools/.git] / kpartx / dasd.c
1 /*
2  * dasd.c
3  *
4  * IBM DASD partition table handling.
5  *
6  * Mostly taken from drivers/s390/block/dasd.c
7  *
8  * Copyright (c) 2005, Hannes Reinecke, SUSE Linux Products GmbH
9  * Copyright IBM Corporation, 2009
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * as published by the Free Software Foundation; either version 2
14  * of the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
23  */
24
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <inttypes.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/sysmacros.h>
32 #include <sys/ioctl.h>
33 #include <linux/hdreg.h>
34 #include <errno.h>
35 #include <string.h>
36 #include <fcntl.h>
37 #include <libdevmapper.h>
38 #include "devmapper.h"
39 #include "kpartx.h"
40 #include "byteorder.h"
41 #include "dasd.h"
42
43 unsigned long long sectors512(unsigned long long sectors, int blocksize)
44 {
45         return sectors * (blocksize >> 9);
46 }
47
48 /*
49  * Magic records per track calculation, copied from fdasd.c
50  */
51 static unsigned int ceil_quot(unsigned int d1, unsigned int d2)
52 {
53         return (d1 + (d2 - 1)) / d2;
54 }
55
56 unsigned int recs_per_track(unsigned int dl)
57 {
58         int dn = ceil_quot(dl + 6, 232) + 1;
59         return 1729 / (10 + 9 + ceil_quot(dl + 6 * dn, 34));
60 }
61
62
63 typedef unsigned int __attribute__((__may_alias__)) label_ints_t;
64
65 /*
66  */
67 int
68 read_dasd_pt(int fd, struct slice all, struct slice *sp, int ns)
69 {
70         int retval = -1;
71         int blocksize;
72         uint64_t disksize;
73         uint64_t offset, size, fmt_size;
74         dasd_information_t info;
75         struct hd_geometry geo;
76         char type[5] = {0,};
77         volume_label_t vlabel;
78         unsigned char *data = NULL;
79         uint64_t blk;
80         int fd_dasd = -1;
81         struct stat sbuf;
82         dev_t dev;
83         char *devname;
84         char pathname[256];
85
86         if (fd < 0) {
87                 return -1;
88         }
89
90         if (fstat(fd, &sbuf) == -1) {
91                 return -1;
92         }
93
94         devname = dm_mapname(major(sbuf.st_rdev), minor(sbuf.st_rdev));
95
96         if (devname != NULL) {
97                 /* We were passed a handle to a dm device.
98                  * Get the first target and operate on that instead.
99                  */
100                 if (!(dev = dm_get_first_dep(devname))) {
101                         free(devname);
102                         return -1;
103                 }
104                 free(devname);
105
106                 if ((unsigned int)major(dev) != 94) {
107                         /* Not a DASD */
108                         return -1;
109                 }
110
111                 /*
112                  * Hard to believe, but there's no simple way to translate
113                  * major/minor into an openable device file, so we have
114                  * to create one for ourselves.
115                  */
116
117                 sprintf(pathname, "/dev/.kpartx-node-%u-%u",
118                         (unsigned int)major(dev), (unsigned int)minor(dev));
119                 if ((fd_dasd = open(pathname, O_RDONLY)) == -1) {
120                         /* Devicenode does not exist. Try to create one */
121                         if (mknod(pathname, 0600 | S_IFBLK, dev) == -1) {
122                                 /* Couldn't create a device node */
123                                 return -1;
124                         }
125                         fd_dasd = open(pathname, O_RDONLY);
126                         /*
127                          * The file will vanish when the last process (we)
128                          * has ceased to access it.
129                          */
130                         unlink(pathname);
131                 }
132                 if (!fd_dasd) {
133                         /* Couldn't open the device */
134                         return -1;
135                 }
136         } else if ((unsigned int)major(sbuf.st_rdev) != 94) {
137                         /* Not a DASD */
138                         return -1;
139         } else {
140                 fd_dasd = fd;
141         }
142
143         if (ioctl(fd_dasd, BIODASDINFO, (unsigned long)&info) != 0) {
144                 info.label_block = 2;
145                 info.FBA_layout = 0;
146                 memcpy(info.type, "ECKD", sizeof(info.type));
147         }
148
149         if (ioctl(fd_dasd, BLKSSZGET, &blocksize) != 0)
150                 goto out;
151
152         if (ioctl(fd_dasd, BLKGETSIZE64, &disksize) != 0)
153                 goto out;
154
155         if (ioctl(fd_dasd, HDIO_GETGEO, (unsigned long)&geo) != 0) {
156                 unsigned int cyl;
157
158                 geo.heads = 15;
159                 geo.sectors = recs_per_track(blocksize);
160                 cyl = disksize / (blocksize * geo.heads * geo.sectors);
161                 if (cyl < LV_COMPAT_CYL)
162                         geo.cylinders = cyl;
163                 else
164                         geo.cylinders = LV_COMPAT_CYL;
165                 geo.start = 0;
166         }
167
168         disksize >>= 9;
169
170         if (blocksize < 512 || blocksize > 4096)
171                 goto out;
172
173         /*
174          * Get volume label, extract name and type.
175          */
176
177         if (!(data = (unsigned char *)malloc(blocksize)))
178                 goto out;
179
180
181         if (lseek(fd_dasd, info.label_block * blocksize, SEEK_SET) == -1)
182                 goto out;
183         if (read(fd_dasd, data, blocksize) == -1) {
184                 perror("read");
185                 goto out;
186         }
187
188         if ((!info.FBA_layout) && (!strcmp(info.type, "ECKD")))
189                 memcpy (&vlabel, data, sizeof(vlabel));
190         else {
191                 bzero(&vlabel,4);
192                 memcpy (&vlabel.vollbl, data, sizeof(vlabel) - 4);
193         }
194         vtoc_ebcdic_dec(vlabel.vollbl, type, 4);
195
196         /*
197          * Three different types: CMS1, VOL1 and LNX1/unlabeled
198          */
199         if (strncmp(type, "CMS1", 4) == 0) {
200                 /*
201                  * VM style CMS1 labeled disk
202                  */
203                 label_ints_t *label = (label_ints_t *) &vlabel;
204
205                 blocksize = label[4];
206                 if (label[14] != 0) {
207                         /* disk is reserved minidisk */
208                         offset = label[14];
209                         size   = sectors512(label[8] - 1, blocksize);
210                 } else {
211                         offset = info.label_block + 1;
212                         size   = sectors512(label[8], blocksize);
213                 }
214                 sp[0].start = sectors512(offset, blocksize);
215                 sp[0].size  = size - sp[0].start;
216                 retval = 1;
217         } else if ((strncmp(type, "VOL1", 4) == 0) &&
218                 (!info.FBA_layout) && (!strcmp(info.type, "ECKD"))) {
219                 /*
220                  * New style VOL1 labeled disk
221                  */
222                 int counter;
223
224                 /* get block number and read then go through format1 labels */
225                 blk = cchhb2blk(&vlabel.vtoc, &geo) + 1;
226                 counter = 0;
227                 if (lseek(fd_dasd, blk * blocksize, SEEK_SET) == -1)
228                         goto out;
229
230                 while (read(fd_dasd, data, blocksize) != -1) {
231                         format1_label_t f1;
232
233                         memcpy(&f1, data, sizeof(format1_label_t));
234
235                         /* skip FMT4 / FMT5 / FMT7 labels */
236                         if (EBCtoASC[f1.DS1FMTID] == '4'
237                             || EBCtoASC[f1.DS1FMTID] == '5'
238                             || EBCtoASC[f1.DS1FMTID] == '7'
239                             || EBCtoASC[f1.DS1FMTID] == '9') {
240                                 blk++;
241                                 continue;
242                         }
243
244                         /* only FMT1 and FMT8 valid at this point */
245                         if (EBCtoASC[f1.DS1FMTID] != '1' &&
246                             EBCtoASC[f1.DS1FMTID] != '8')
247                                 break;
248
249                         /* OK, we got valid partition data */
250                         offset = cchh2blk(&f1.DS1EXT1.llimit, &geo);
251                         size  = cchh2blk(&f1.DS1EXT1.ulimit, &geo) -
252                                 offset + geo.sectors;
253                         sp[counter].start = sectors512(offset, blocksize);
254                         sp[counter].size  = sectors512(size, blocksize);
255                         counter++;
256                         blk++;
257                 }
258                 retval = counter;
259         } else {
260                 /*
261                  * Old style LNX1 or unlabeled disk
262                  */
263                 if (strncmp(type, "LNX1", 4) == 0) {
264                         if (vlabel.ldl_version == 0xf2) {
265                                 fmt_size = sectors512(vlabel.formatted_blocks,
266                                                       blocksize);
267                         } else if (!strcmp(info.type, "ECKD")) {
268                                 /* formatted w/o large volume support */
269                                 fmt_size = geo.cylinders * geo.heads
270                                         * geo.sectors * (blocksize >> 9);
271                         } else {
272                                 /* old label and no usable disk geometry
273                                  * (e.g. DIAG) */
274                                 fmt_size = disksize;
275                         }
276                         size = disksize;
277                         if (fmt_size < size)
278                                 size = fmt_size;
279                 } else
280                         size = disksize;
281
282                 sp[0].start = sectors512(info.label_block + 1, blocksize);
283                 sp[0].size  = size - sp[0].start;
284                 retval = 1;
285         }
286
287 out:
288         if (data != NULL)
289                 free(data);
290         if (fd_dasd != -1 && fd_dasd != fd)
291                 close(fd_dasd);
292         return retval;
293 }