ref: c4ecd0fee0f0cef485a223d6e638a56bafd5bbda
dir: /sys/src/cmd/disk/prep/prep.c/
/*
* prep - prepare plan9 disk partition
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <disk.h>
#include "edit.h"
enum {
Maxpath = 128,
};
static int blank;
static int file;
static int doautox;
static int printflag;
static Part **opart;
static int nopart;
static char *osecbuf;
static char *secbuf;
static int rdonly;
static int dowrite;
static int docache;
static int donvram;
static void autoxpart(Edit*);
static Part *mkpart(char*, vlong, vlong, int);
static void rdpart(Edit*);
static void wrpart(Edit*);
static void checkfat(Disk*);
static void cmdsum(Edit*, Part*, vlong, vlong);
static char *cmdadd(Edit*, char*, vlong, vlong);
static char *cmddel(Edit*, Part*);
static char *cmdokname(Edit*, char*);
static char *cmdwrite(Edit*);
static char *cmdctlprint(Edit*, int, char**);
Edit edit = {
.add= cmdadd,
.del= cmddel,
.okname=cmdokname,
.sum= cmdsum,
.write= cmdwrite,
.unit= "sector",
};
typedef struct Auto Auto;
struct Auto
{
char *name;
uvlong min;
uvlong max;
uint weight;
uchar alloc;
uvlong size;
};
#define TB (1024LL*GB)
#define GB (1024*1024*1024)
#define MB (1024*1024)
#define KB (1024)
/*
* Order matters -- this is the layout order on disk.
*/
Auto autox[] =
{
{ "9fat", 10*MB, 100*MB, 10, },
{ "nvram", 512, 512, 1, },
{ "fscfg", 512, 512, 1, },
{ "fs", 200*MB, 0, 10, },
{ "fossil", 200*MB, 0, 4, },
{ "arenas", 500*MB, 0, 20, },
{ "isect", 25*MB, 0, 1, },
{ "bloom", 4*MB, 512*MB, 1, },
{ "other", 200*MB, 0, 4, },
{ "swap", 100*MB, 512*MB, 1, },
{ "cache", 50*MB, 1*GB, 2, },
{ "fscache", 200*MB, 0, 4, },
{ "fsworm", 500*MB, 0, 20, },
};
void
usage(void)
{
fprint(2, "usage: disk/prep [-bcfprw] [-a partname]... [-s sectorsize] /dev/sdC0/plan9\n");
exits("usage");
}
void
main(int argc, char **argv)
{
int i;
char *p;
Disk *disk;
vlong secsize;
secsize = 0;
ARGBEGIN{
case 'a':
p = EARGF(usage());
for(i=0; i<nelem(autox); i++){
if(strcmp(p, autox[i].name) == 0){
if(autox[i].alloc){
fprint(2, "you said -a %s more than once.\n", p);
usage();
}
autox[i].alloc = 1;
break;
}
}
if(i == nelem(autox)){
fprint(2, "don't know how to create automatic partition %s\n", p);
usage();
}
doautox = 1;
break;
case 'b':
blank++;
break;
case 'c':
docache++;
break;
case 'f':
file++;
break;
case 'n':
donvram++;
break;
case 'p':
printflag++;
rdonly++;
break;
case 'r':
rdonly++;
break;
case 's':
secsize = atoi(ARGF());
break;
case 'w':
dowrite++;
break;
default:
usage();
}ARGEND;
if(argc != 1)
usage();
disk = opendisk(argv[0], rdonly, file);
if(disk == nil)
sysfatal("cannot open disk: %r");
if(secsize != 0) {
disk->secsize = secsize;
disk->secs = disk->size / secsize;
}
edit.unitsz = disk->secsize;
edit.end = disk->secs;
checkfat(disk);
secbuf = emalloc(disk->secsize+1);
osecbuf = emalloc(disk->secsize+1);
edit.disk = disk;
if(blank == 0)
rdpart(&edit);
opart = emalloc(edit.npart*sizeof(opart[0]));
/* save old partition table */
for(i=0; i<edit.npart; i++)
opart[i] = edit.part[i];
nopart = edit.npart;
if(printflag) {
runcmd(&edit, "P");
exits(0);
}
if(doautox)
autoxpart(&edit);
if(dowrite) {
runcmd(&edit, "w");
exits(0);
}
runcmd(&edit, "p");
for(;;) {
fprint(2, ">>> ");
runcmd(&edit, getline(&edit));
}
}
static void
cmdsum(Edit *edit, Part *p, vlong a, vlong b)
{
vlong sz, div;
char *suf, *name;
char c;
c = p && p->changed ? '\'' : ' ';
name = p ? p->name : "empty";
sz = (b-a)*edit->disk->secsize;
if(sz >= 1*TB){
suf = "TB";
div = TB;
}else if(sz >= 1*GB){
suf = "GB";
div = GB;
}else if(sz >= 1*MB){
suf = "MB";
div = MB;
}else if(sz >= 1*KB){
suf = "KB";
div = KB;
}else{
if (sz < 0)
fprint(2, "%s: negative size!\n", argv0);
suf = "B ";
div = 1;
}
if(div == 1)
print("%c %-12s %*lld %-*lld (%lld sectors, %lld %s)\n", c, name,
edit->disk->width, a, edit->disk->width, b, b-a, sz, suf);
else
print("%c %-12s %*lld %-*lld (%lld sectors, %lld.%.2d %s)\n", c, name,
edit->disk->width, a, edit->disk->width, b, b-a,
sz/div, (int)(((sz%div)*100)/div), suf);
}
static char*
cmdadd(Edit *edit, char *name, vlong start, vlong end)
{
if(start < 2 && strcmp(name, "9fat") != 0)
return "overlaps with the pbs and/or the partition table";
return addpart(edit, mkpart(name, start, end, 1));
}
static char*
cmddel(Edit *edit, Part *p)
{
return delpart(edit, p);
}
static char*
cmdwrite(Edit *edit)
{
wrpart(edit);
return nil;
}
static char isfrog[256]={
/*NUL*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*BKS*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*DLE*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*CAN*/ 1, 1, 1, 1, 1, 1, 1, 1,
[' '] 1,
['/'] 1,
[0x7f] 1,
};
static char*
cmdokname(Edit*, char *elem)
{
for(; *elem; elem++)
if(isfrog[*(uchar*)elem])
return "bad character in name";
return nil;
}
static Part*
mkpart(char *name, vlong start, vlong end, int changed)
{
Part *p;
p = emalloc(sizeof(*p));
p->name = estrdup(name);
p->ctlname = estrdup(name);
p->start = start;
p->end = end;
p->changed = changed;
return p;
}
/* plan9 partition is first sector of the disk */
static void
rdpart(Edit *edit)
{
int i, nline, nf, waserr;
vlong a, b;
char *line[128];
char *f[5];
char *err;
Disk *disk;
disk = edit->disk;
seek(disk->fd, disk->secsize, 0);
if(readn(disk->fd, osecbuf, disk->secsize) != disk->secsize)
return;
osecbuf[disk->secsize] = '\0';
memmove(secbuf, osecbuf, disk->secsize+1);
if(strncmp(secbuf, "part", 4) != 0){
fprint(2, "no plan9 partition table found\n");
return;
}
waserr = 0;
nline = getfields(secbuf, line, nelem(line), 1, "\n");
for(i=0; i<nline; i++){
if(strncmp(line[i], "part", 4) != 0) {
Error:
if(waserr == 0)
fprint(2, "syntax error reading partition\n");
waserr = 1;
continue;
}
nf = getfields(line[i], f, nelem(f), 1, " \t\r");
if(nf != 4 || strcmp(f[0], "part") != 0)
goto Error;
a = strtoll(f[2], 0, 0);
b = strtoll(f[3], 0, 0);
if(a >= b)
goto Error;
if(err = addpart(edit, mkpart(f[1], a, b, 0))) {
fprint(2, "?%s: not continuing\n", err);
exits("partition");
}
}
}
static vlong
min(vlong a, vlong b)
{
if(a < b)
return a;
return b;
}
static void
autoxpart(Edit *edit)
{
int i, totw, futz;
vlong secs, secsize, psecsize, s, e, pa;
long stride;
char *err;
if(edit->npart > 0) {
if(doautox)
fprint(2, "partitions already exist; not repartitioning\n");
return;
}
secs = edit->disk->secs;
secsize = edit->disk->secsize;
psecsize = edit->disk->psecsize;
stride = psecsize / secsize;
pa = (edit->disk->offset - edit->disk->physalign + stride) % stride;
secs -= (secs + pa) % stride;
for(;;){
/* compute total weights */
totw = 0;
for(i=0; i<nelem(autox); i++){
if(autox[i].alloc==0 || autox[i].size)
continue;
totw += autox[i].weight;
}
if(totw == 0)
break;
if(secs <= 0){
fprint(2, "ran out of disk space during autoxpartition.\n");
return;
}
/* assign any minimums for small disks */
futz = 0;
for(i=0; i<nelem(autox); i++){
if(autox[i].alloc==0 || autox[i].size)
continue;
s = (secs*autox[i].weight)/totw;
if(s < autox[i].min/secsize){
autox[i].size = autox[i].min/secsize;
secs -= autox[i].size;
futz = 1;
break;
}
}
if(futz)
continue;
/* assign any maximums for big disks */
futz = 0;
for(i=0; i<nelem(autox); i++){
if(autox[i].alloc==0 || autox[i].size)
continue;
s = (secs*autox[i].weight)/totw;
if(autox[i].max && s > autox[i].max/secsize){
autox[i].size = autox[i].max/secsize;
secs -= autox[i].size;
futz = 1;
break;
}
}
if(futz)
continue;
/* finally, assign partition sizes according to weights */
for(i=0; i<nelem(autox); i++){
if(autox[i].alloc==0 || autox[i].size)
continue;
s = (secs*autox[i].weight)/totw;
autox[i].size = s;
/* use entire disk even in face of rounding errors */
secs -= autox[i].size;
totw -= autox[i].weight;
}
}
s = 0;
if(autox[0].alloc == 0){
/* if no 9fat, reserve space for plan9 partition table */
s = 2;
if((s + pa) % stride) s += stride - (s + pa) % stride;
}
secs = edit->disk->secs;
for(i=0; i<nelem(autox); i++){
if(autox[i].alloc == 0)
continue;
e = (s + autox[i].size);
if((e + pa) % stride) e += stride - (e + pa) % stride;
if(e>secs) e = secs - stride + (secs + pa) % stride;
print("%s %llud\n", autox[i].name, e - s);
if(err = addpart(edit, mkpart(autox[i].name, s, e, 1)))
fprint(2, "addpart %s: %s\n", autox[i].name, err);
s = e;
}
}
static void
restore(Edit *edit, int ctlfd)
{
int i;
vlong offset;
offset = edit->disk->offset;
fprint(2, "attempting to restore partitions to previous state\n");
if(seek(edit->disk->wfd, edit->disk->secsize, 0) != 0){
fprint(2, "cannot restore: error seeking on disk\n");
exits("inconsistent");
}
if(write(edit->disk->wfd, osecbuf, edit->disk->secsize) != edit->disk->secsize){
fprint(2, "cannot restore: couldn't write old partition table to disk\n");
exits("inconsistent");
}
if(ctlfd >= 0){
for(i=0; i<edit->npart; i++)
fprint(ctlfd, "delpart %s", edit->part[i]->name);
for(i=0; i<nopart; i++){
if(fprint(ctlfd, "part %s %lld %lld", opart[i]->name, opart[i]->start+offset, opart[i]->end+offset) < 0){
fprint(2, "restored disk partition table but not kernel; reboot\n");
exits("inconsistent");
}
}
}
exits("restored");
}
static void
wrpart(Edit *edit)
{
int i, n;
Disk *disk;
disk = edit->disk;
memset(secbuf, 0, disk->secsize);
n = 0;
for(i=0; i<edit->npart; i++)
n += snprint(secbuf+n, disk->secsize-n, "part %s %lld %lld\n",
edit->part[i]->name, edit->part[i]->start, edit->part[i]->end);
if(seek(disk->wfd, disk->secsize, 0) != disk->secsize){
fprint(2, "error seeking %d %lld on disk: %r\n", disk->wfd, disk->secsize);
exits("seek");
}
if(write(disk->wfd, secbuf, disk->secsize) != disk->secsize){
fprint(2, "error writing partition table to disk\n");
restore(edit, -1);
}
if(ctldiff(edit, disk->ctlfd) < 0)
fprint(2, "?warning: partitions could not be updated in devsd\n");
}
/*
* Look for a boot sector in sector 1, as would be
* the case if editing /dev/sdC0/data when that
* was really a bootable disk.
*/
static void
checkfat(Disk *disk)
{
uchar buf[32];
if(seek(disk->fd, disk->secsize, 0) < 0
|| read(disk->fd, buf, sizeof(buf)) < sizeof(buf))
return;
if(buf[0] != 0xEB || buf[1] != 0x3C || buf[2] != 0x90)
return;
fprint(2,
"there's a fat partition where the\n"
"plan9 partition table would go.\n"
"if you really want to overwrite it, zero\n"
"the second sector of the disk and try again\n");
exits("fat partition");
}