1 e1dddc05 2004-06-17 devnull #include <u.h>
2 e1dddc05 2004-06-17 devnull #include <libc.h>
3 e1dddc05 2004-06-17 devnull #include <bio.h>
4 e1dddc05 2004-06-17 devnull #include <ctype.h>
5 e1dddc05 2004-06-17 devnull #include <disk.h>
7 e1dddc05 2004-06-17 devnull static Disk*
8 e1dddc05 2004-06-17 devnull mkwidth(Disk *disk)
10 e1dddc05 2004-06-17 devnull char buf[40];
12 e1dddc05 2004-06-17 devnull sprint(buf, "%lld", disk->size);
13 e1dddc05 2004-06-17 devnull disk->width = strlen(buf);
14 e1dddc05 2004-06-17 devnull return disk;
18 e1dddc05 2004-06-17 devnull * Discover the disk geometry by various sleazeful means.
20 e1dddc05 2004-06-17 devnull * First, if there is a partition table in sector 0,
21 e1dddc05 2004-06-17 devnull * see if all the partitions have the same end head
22 e1dddc05 2004-06-17 devnull * and sector; if so, we'll assume that that's the
23 e1dddc05 2004-06-17 devnull * right count.
25 e1dddc05 2004-06-17 devnull * If that fails, we'll try looking at the geometry that the ATA
26 e1dddc05 2004-06-17 devnull * driver supplied, if any, and translate that as a
27 e1dddc05 2004-06-17 devnull * BIOS might.
29 e1dddc05 2004-06-17 devnull * If that too fails, which should only happen on a SCSI
30 e1dddc05 2004-06-17 devnull * disk with no currently defined partitions, we'll try
31 e1dddc05 2004-06-17 devnull * various common (h, s) pairs used by BIOSes when faking
32 e1dddc05 2004-06-17 devnull * the geometries.
34 e1dddc05 2004-06-17 devnull typedef struct Table Table;
35 e1dddc05 2004-06-17 devnull typedef struct Tentry Tentry;
36 e1dddc05 2004-06-17 devnull struct Tentry {
37 e1dddc05 2004-06-17 devnull uchar active; /* active flag */
38 e1dddc05 2004-06-17 devnull uchar starth; /* starting head */
39 e1dddc05 2004-06-17 devnull uchar starts; /* starting sector */
40 e1dddc05 2004-06-17 devnull uchar startc; /* starting cylinder */
41 e1dddc05 2004-06-17 devnull uchar type; /* partition type */
42 e1dddc05 2004-06-17 devnull uchar endh; /* ending head */
43 e1dddc05 2004-06-17 devnull uchar ends; /* ending sector */
44 e1dddc05 2004-06-17 devnull uchar endc; /* ending cylinder */
45 e1dddc05 2004-06-17 devnull uchar xlba[4]; /* starting LBA from beginning of disc */
46 e1dddc05 2004-06-17 devnull uchar xsize[4]; /* size in sectors */
49 e1dddc05 2004-06-17 devnull Toffset = 446, /* offset of partition table in sector */
50 e1dddc05 2004-06-17 devnull Magic0 = 0x55,
51 e1dddc05 2004-06-17 devnull Magic1 = 0xAA,
52 cbeb0b26 2006-04-01 devnull NTentry = 4
54 e1dddc05 2004-06-17 devnull struct Table {
55 e1dddc05 2004-06-17 devnull Tentry entry[NTentry];
56 e1dddc05 2004-06-17 devnull uchar magic[2];
58 e1dddc05 2004-06-17 devnull static int
59 e1dddc05 2004-06-17 devnull partitiongeometry(Disk *disk)
61 e1dddc05 2004-06-17 devnull char *rawname;
62 e1dddc05 2004-06-17 devnull int i, h, rawfd, s;
63 e1dddc05 2004-06-17 devnull uchar buf[512];
64 e1dddc05 2004-06-17 devnull Table *t;
66 e1dddc05 2004-06-17 devnull t = (Table*)(buf + Toffset);
69 e1dddc05 2004-06-17 devnull * look for an MBR first in the /dev/sdXX/data partition, otherwise
70 e1dddc05 2004-06-17 devnull * attempt to fall back on the current partition.
72 e1dddc05 2004-06-17 devnull rawname = malloc(strlen(disk->prefix) + 5); /* prefix + "data" + nul */
73 e1dddc05 2004-06-17 devnull if(rawname == nil)
74 e1dddc05 2004-06-17 devnull return -1;
76 e1dddc05 2004-06-17 devnull strcpy(rawname, disk->prefix);
77 e1dddc05 2004-06-17 devnull strcat(rawname, "data");
78 e1dddc05 2004-06-17 devnull rawfd = open(rawname, OREAD);
79 e1dddc05 2004-06-17 devnull free(rawname);
80 e1dddc05 2004-06-17 devnull if(rawfd >= 0
81 e1dddc05 2004-06-17 devnull && seek(rawfd, 0, 0) >= 0
82 e1dddc05 2004-06-17 devnull && readn(rawfd, buf, 512) == 512
83 e1dddc05 2004-06-17 devnull && t->magic[0] == Magic0
84 e1dddc05 2004-06-17 devnull && t->magic[1] == Magic1) {
85 e1dddc05 2004-06-17 devnull close(rawfd);
87 e1dddc05 2004-06-17 devnull if(rawfd >= 0)
88 e1dddc05 2004-06-17 devnull close(rawfd);
89 e1dddc05 2004-06-17 devnull if(seek(disk->fd, 0, 0) < 0
90 e1dddc05 2004-06-17 devnull || readn(disk->fd, buf, 512) != 512
91 e1dddc05 2004-06-17 devnull || t->magic[0] != Magic0
92 e1dddc05 2004-06-17 devnull || t->magic[1] != Magic1) {
93 e1dddc05 2004-06-17 devnull return -1;
97 e1dddc05 2004-06-17 devnull h = s = -1;
98 e1dddc05 2004-06-17 devnull for(i=0; i<NTentry; i++) {
99 e1dddc05 2004-06-17 devnull if(t->entry[i].type == 0)
100 e1dddc05 2004-06-17 devnull continue;
102 e1dddc05 2004-06-17 devnull t->entry[i].ends &= 63;
103 e1dddc05 2004-06-17 devnull if(h == -1) {
104 e1dddc05 2004-06-17 devnull h = t->entry[i].endh;
105 e1dddc05 2004-06-17 devnull s = t->entry[i].ends;
106 e1dddc05 2004-06-17 devnull } else {
108 e1dddc05 2004-06-17 devnull * Only accept the partition info if every
109 e1dddc05 2004-06-17 devnull * partition is consistent.
111 e1dddc05 2004-06-17 devnull if(h != t->entry[i].endh || s != t->entry[i].ends)
112 e1dddc05 2004-06-17 devnull return -1;
116 e1dddc05 2004-06-17 devnull if(h == -1)
117 e1dddc05 2004-06-17 devnull return -1;
119 e1dddc05 2004-06-17 devnull disk->h = h+1; /* heads count from 0 */
120 e1dddc05 2004-06-17 devnull disk->s = s; /* sectors count from 1 */
121 e1dddc05 2004-06-17 devnull disk->c = disk->secs / (disk->h*disk->s);
122 e1dddc05 2004-06-17 devnull disk->chssrc = Gpart;
123 e1dddc05 2004-06-17 devnull return 0;
127 e1dddc05 2004-06-17 devnull * If there is ATA geometry, use it, perhaps massaged.
129 e1dddc05 2004-06-17 devnull static int
130 e1dddc05 2004-06-17 devnull drivergeometry(Disk *disk)
134 e1dddc05 2004-06-17 devnull if(disk->c == 0 || disk->h == 0 || disk->s == 0)
135 e1dddc05 2004-06-17 devnull return -1;
137 e1dddc05 2004-06-17 devnull disk->chssrc = Gdisk;
138 e1dddc05 2004-06-17 devnull if(disk->c < 1024)
139 e1dddc05 2004-06-17 devnull return 0;
141 e1dddc05 2004-06-17 devnull switch(disk->h) {
142 e1dddc05 2004-06-17 devnull case 15:
143 e1dddc05 2004-06-17 devnull disk->h = 255;
144 e1dddc05 2004-06-17 devnull disk->c /= 17;
145 e1dddc05 2004-06-17 devnull return 0;
148 25745eb3 2008-06-05 rsc for(m = 2; m*disk->h < 256; m *= 2) {
149 25745eb3 2008-06-05 rsc if(disk->c/m < 1024) {
150 25745eb3 2008-06-05 rsc disk->c /= m;
151 25745eb3 2008-06-05 rsc disk->h *= m;
156 25745eb3 2008-06-05 rsc /* set to 255, 63 and be done with it */
157 25745eb3 2008-06-05 rsc disk->h = 255;
158 25745eb3 2008-06-05 rsc disk->s = 63;
159 25745eb3 2008-06-05 rsc disk->c = disk->secs / (disk->h * disk->s);
164 e1dddc05 2004-06-17 devnull * There's no ATA geometry and no partitions.
165 e1dddc05 2004-06-17 devnull * Our guess is as good as anyone's.
167 e1dddc05 2004-06-17 devnull static struct {
170 e1dddc05 2004-06-17 devnull } guess[] = {
173 e1dddc05 2004-06-17 devnull 128, 63,
174 e1dddc05 2004-06-17 devnull 255, 63,
176 e1dddc05 2004-06-17 devnull static int
177 e1dddc05 2004-06-17 devnull guessgeometry(Disk *disk)
182 e1dddc05 2004-06-17 devnull disk->chssrc = Gguess;
183 e1dddc05 2004-06-17 devnull c = 1024;
184 e1dddc05 2004-06-17 devnull for(i=0; i<nelem(guess); i++)
185 e1dddc05 2004-06-17 devnull if(c*guess[i].h*guess[i].s >= disk->secs) {
186 e1dddc05 2004-06-17 devnull disk->h = guess[i].h;
187 e1dddc05 2004-06-17 devnull disk->s = guess[i].s;
188 e1dddc05 2004-06-17 devnull disk->c = disk->secs / (disk->h * disk->s);
189 e1dddc05 2004-06-17 devnull return 0;
192 e1dddc05 2004-06-17 devnull /* use maximum values */
193 e1dddc05 2004-06-17 devnull disk->h = 255;
194 e1dddc05 2004-06-17 devnull disk->s = 63;
195 e1dddc05 2004-06-17 devnull disk->c = disk->secs / (disk->h * disk->s);
196 e1dddc05 2004-06-17 devnull return 0;
199 e1dddc05 2004-06-17 devnull static void
200 e1dddc05 2004-06-17 devnull findgeometry(Disk *disk)
202 e1dddc05 2004-06-17 devnull if(partitiongeometry(disk) < 0
203 e1dddc05 2004-06-17 devnull && drivergeometry(disk) < 0
204 e1dddc05 2004-06-17 devnull && guessgeometry(disk) < 0) { /* can't happen */
205 e1dddc05 2004-06-17 devnull print("we're completely confused about your disk; sorry\n");
206 e1dddc05 2004-06-17 devnull assert(0);
210 e1dddc05 2004-06-17 devnull static Disk*
211 e1dddc05 2004-06-17 devnull openfile(Disk *disk)
215 e1dddc05 2004-06-17 devnull if((d = dirfstat(disk->fd)) == nil){
216 e1dddc05 2004-06-17 devnull free(disk);
217 e1dddc05 2004-06-17 devnull return nil;
220 e1dddc05 2004-06-17 devnull disk->secsize = 512;
221 e1dddc05 2004-06-17 devnull disk->size = d->length;
222 e1dddc05 2004-06-17 devnull disk->secs = disk->size / disk->secsize;
223 e1dddc05 2004-06-17 devnull disk->offset = 0;
224 e1dddc05 2004-06-17 devnull free(d);
226 e1dddc05 2004-06-17 devnull findgeometry(disk);
227 e1dddc05 2004-06-17 devnull return mkwidth(disk);
230 e1dddc05 2004-06-17 devnull static Disk*
231 e1dddc05 2004-06-17 devnull opensd(Disk *disk)
233 e1dddc05 2004-06-17 devnull Biobuf b;
234 e1dddc05 2004-06-17 devnull char *p, *f[10];
237 e1dddc05 2004-06-17 devnull Binit(&b, disk->ctlfd, OREAD);
238 e1dddc05 2004-06-17 devnull while(p = Brdline(&b, '\n')) {
239 e1dddc05 2004-06-17 devnull p[Blinelen(&b)-1] = '\0';
240 e1dddc05 2004-06-17 devnull nf = tokenize(p, f, nelem(f));
241 e1dddc05 2004-06-17 devnull if(nf >= 3 && strcmp(f[0], "geometry") == 0) {
242 e1dddc05 2004-06-17 devnull disk->secsize = strtoll(f[2], 0, 0);
243 e1dddc05 2004-06-17 devnull if(nf >= 6) {
244 e1dddc05 2004-06-17 devnull disk->c = strtol(f[3], 0, 0);
245 e1dddc05 2004-06-17 devnull disk->h = strtol(f[4], 0, 0);
246 e1dddc05 2004-06-17 devnull disk->s = strtol(f[5], 0, 0);
249 e1dddc05 2004-06-17 devnull if(nf >= 4 && strcmp(f[0], "part") == 0 && strcmp(f[1], disk->part) == 0) {
250 e1dddc05 2004-06-17 devnull disk->offset = strtoll(f[2], 0, 0);
251 e1dddc05 2004-06-17 devnull disk->secs = strtoll(f[3], 0, 0) - disk->offset;
256 e1dddc05 2004-06-17 devnull disk->size = disk->secs * disk->secsize;
257 e1dddc05 2004-06-17 devnull if(disk->size <= 0) {
258 e1dddc05 2004-06-17 devnull strcpy(disk->part, "");
259 e1dddc05 2004-06-17 devnull disk->type = Tfile;
260 e1dddc05 2004-06-17 devnull return openfile(disk);
263 e1dddc05 2004-06-17 devnull findgeometry(disk);
264 e1dddc05 2004-06-17 devnull return mkwidth(disk);
268 e1dddc05 2004-06-17 devnull opendisk(char *disk, int rdonly, int noctl)
270 e1dddc05 2004-06-17 devnull char *p, *q;
271 e1dddc05 2004-06-17 devnull Disk *d;
273 e1dddc05 2004-06-17 devnull d = malloc(sizeof(*d));
274 e1dddc05 2004-06-17 devnull if(d == nil)
275 e1dddc05 2004-06-17 devnull return nil;
277 e1dddc05 2004-06-17 devnull d->fd = d->wfd = d->ctlfd = -1;
278 e1dddc05 2004-06-17 devnull d->rdonly = rdonly;
280 e1dddc05 2004-06-17 devnull d->fd = open(disk, OREAD);
281 e1dddc05 2004-06-17 devnull if(d->fd < 0) {
282 e1dddc05 2004-06-17 devnull werrstr("cannot open disk file");
283 e1dddc05 2004-06-17 devnull free(d);
284 e1dddc05 2004-06-17 devnull return nil;
287 e1dddc05 2004-06-17 devnull if(rdonly == 0) {
288 e1dddc05 2004-06-17 devnull d->wfd = open(disk, OWRITE);
289 e1dddc05 2004-06-17 devnull if(d->wfd < 0)
290 e1dddc05 2004-06-17 devnull d->rdonly = 1;
293 e1dddc05 2004-06-17 devnull if(noctl)
294 e1dddc05 2004-06-17 devnull return openfile(d);
296 e1dddc05 2004-06-17 devnull p = malloc(strlen(disk) + 4); /* 4: slop for "ctl\0" */
297 e1dddc05 2004-06-17 devnull if(p == nil) {
298 e1dddc05 2004-06-17 devnull close(d->wfd);
299 e1dddc05 2004-06-17 devnull close(d->fd);
300 e1dddc05 2004-06-17 devnull free(d);
301 e1dddc05 2004-06-17 devnull return nil;
303 e1dddc05 2004-06-17 devnull strcpy(p, disk);
305 e1dddc05 2004-06-17 devnull /* check for floppy(3) disk */
306 e1dddc05 2004-06-17 devnull if(strlen(p) >= 7) {
307 e1dddc05 2004-06-17 devnull q = p+strlen(p)-7;
308 604ad4d8 2005-11-01 devnull if(q[0] == 'f' && q[1] == 'd' && isdigit((uchar)q[2]) && strcmp(q+3, "disk") == 0) {
309 e1dddc05 2004-06-17 devnull strcpy(q+3, "ctl");
310 e1dddc05 2004-06-17 devnull if((d->ctlfd = open(p, ORDWR)) >= 0) {
311 e1dddc05 2004-06-17 devnull *q = '\0';
312 e1dddc05 2004-06-17 devnull d->prefix = p;
313 e1dddc05 2004-06-17 devnull d->type = Tfloppy;
314 e1dddc05 2004-06-17 devnull return openfile(d);
319 e1dddc05 2004-06-17 devnull /* attempt to find sd(3) disk or partition */
320 e1dddc05 2004-06-17 devnull if(q = strrchr(p, '/'))
325 e1dddc05 2004-06-17 devnull strcpy(q, "ctl");
326 e1dddc05 2004-06-17 devnull if((d->ctlfd = open(p, ORDWR)) >= 0) {
327 e1dddc05 2004-06-17 devnull *q = '\0';
328 e1dddc05 2004-06-17 devnull d->prefix = p;
329 e1dddc05 2004-06-17 devnull d->type = Tsd;
330 e1dddc05 2004-06-17 devnull d->part = strdup(disk+(q-p));
331 e1dddc05 2004-06-17 devnull if(d->part == nil){
332 e1dddc05 2004-06-17 devnull close(d->ctlfd);
333 e1dddc05 2004-06-17 devnull close(d->wfd);
334 e1dddc05 2004-06-17 devnull close(d->fd);
335 e1dddc05 2004-06-17 devnull free(p);
336 e1dddc05 2004-06-17 devnull free(d);
337 e1dddc05 2004-06-17 devnull return nil;
339 e1dddc05 2004-06-17 devnull return opensd(d);
342 e1dddc05 2004-06-17 devnull *q = '\0';
343 e1dddc05 2004-06-17 devnull d->prefix = p;
344 e1dddc05 2004-06-17 devnull /* assume we just have a normal file */
345 e1dddc05 2004-06-17 devnull d->type = Tfile;
346 e1dddc05 2004-06-17 devnull return openfile(d);