ref: 83246e296ea433b65b9d295b5e08fedd39ff1ab7
dir: /appl/cmd/disk/prep/prep.b/
implement Prep;
#
# prepare plan 9/inferno disk partition
#
include "sys.m";
sys: Sys;
include "draw.m";
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "disks.m";
disks: Disks;
Disk: import disks;
include "pedit.m";
pedit: Pedit;
Edit, Part: import pedit;
include "arg.m";
Prep: module
{
init: fn(nil: ref Draw->Context, nil: list of string);
};
blank := 0;
file := 0;
doauto := 0;
printflag := 0;
opart: array of ref Part;
secbuf: array of byte;
osecbuf: array of byte;
zeroes: array of byte;
rdonly := 0;
dowrite := 0;
Prepedit: type Edit[string];
edit: ref Edit;
Auto: adt
{
name: string;
min: big;
max: big;
weight: int;
alloc: int;
size: big;
};
KB: con big 1024;
MB: con KB*KB;
GB: con KB*MB;
#
# Order matters -- this is the layout order on disk.
#
auto: array of Auto = array[] of {
("9fat", big 10*MB, big 100*MB, 10, 0, big 0),
("nvram", big 512, big 512, 1, 0, big 0),
("fscfg", big 512, big 512, 1, 0, big 0),
("fs", big 200*MB, big 0, 10, 0, big 0),
("fossil", big 200*MB, big 0, 4, 0, big 0),
("arenas", big 500*MB, big 0, 20, 0, big 0),
("isect", big 25*MB, big 0, 1, 0, big 0),
("other", big 200*MB, big 0, 4, 0, big 0),
("swap", big 100*MB, big 512*MB, 1, 0, big 0),
("cache", big 50*MB, big 1*GB, 2, 0, big 0),
};
stderr: ref Sys->FD;
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
bufio = load Bufio Bufio->PATH;
disks = load Disks Disks->PATH;
pedit = load Pedit Pedit->PATH;
sys->pctl(Sys->FORKFD, nil);
disks->init();
pedit->init();
edit = Edit.mk("sector");
edit.add = cmdadd;
edit.del = cmddel;
edit.okname = cmdokname;
edit.sum = cmdsum;
edit.write = cmdwrite;
stderr = sys->fildes(2);
secsize := 0;
arg := load Arg Arg->PATH;
arg->init(args);
arg->setusage("disk/prep [-bfprw] [-a partname]... [-s sectorsize] /dev/sdC0/plan9");
while((o := arg->opt()) != 0)
case o {
'a' =>
p := arg->earg();
for(i:=0; i<len auto; i++){
if(p == auto[i].name){
if(auto[i].alloc){
sys->fprint(stderr, "you said -a %s more than once.\n", p);
arg->usage();
}
auto[i].alloc = 1;
break;
}
}
if(i == len auto){
sys->fprint(stderr, "don't know how to create automatic partition %s\n", p);
arg->usage();
}
doauto = 1;
'b' =>
blank++;
'f' =>
file++;
'p' =>
printflag++;
rdonly++;
'r' =>
rdonly++;
's' =>
secsize = int arg->earg();
'w' =>
dowrite++;
* =>
arg->usage();
}
args = arg->argv();
if(len args != 1)
arg->usage();
arg = nil;
mode := Sys->ORDWR;
if(rdonly)
mode = Sys->OREAD;
disk := Disk.open(hd args, mode, file);
if(disk == nil) {
sys->fprint(stderr, "cannot open disk: %r\n");
exits("opendisk");
}
if(secsize != 0) {
disk.secsize = secsize;
disk.secs = disk.size / big secsize;
}
edit.end = disk.secs;
checkfat(disk);
secbuf = array[disk.secsize+1] of byte;
osecbuf = array[disk.secsize+1] of byte;
zeroes = array[disk.secsize+1] of {* => byte 0};
edit.disk = disk;
if(blank == 0)
rdpart(edit);
# save old partition table
opart = array[len edit.part] of ref Part;
opart[0:] = edit.part;
if(printflag) {
edit.runcmd("P");
exits(nil);
}
if(doauto)
autopart(edit);
if(dowrite) {
edit.runcmd("w");
exits(nil);
}
edit.runcmd("p");
for(;;) {
sys->fprint(stderr, ">>> ");
edit.runcmd(edit.getline());
}
}
cmdsum(edit: ref Edit, p: ref Part, a: big, b: big)
{
c := ' ';
name := "empty";
if(p != nil){
if(p.changed)
c = '\'';
name = p.name;
}
sz := (b-a)*big edit.disk.secsize;
suf := "B ";
div := big 1;
if(sz >= big 1*GB){
suf = "GB";
div = GB;
}else if(sz >= big 1*MB){
suf = "MB";
div = MB;
}else if(sz >= big 1*KB){
suf = "KB";
div = KB;
}
if(div == big 1)
sys->print("%c %-12s %*bd %-*bd (%bd sectors, %bd %s)\n", c, name,
edit.disk.width, a, edit.disk.width, b, b-a, sz, suf);
else
sys->print("%c %-12s %*bd %-*bd (%bd sectors, %bd.%.2d %s)\n", c, name,
edit.disk.width, a, edit.disk.width, b, b-a,
sz/div, int (((sz%div)*big 100)/div), suf);
}
cmdadd(edit: ref Edit, name: string, start: big, end: big): string
{
if(start < big 2 && name == "9fat")
return "overlaps with the pbs and/or the partition table";
return edit.addpart(mkpart(name, start, end, 1));
}
cmddel(edit: ref Edit, p: ref Part): string
{
return edit.delpart(p);
}
cmdwrite(edit: ref Edit): string
{
wrpart(edit);
return nil;
}
isfrog := array[256] of {
byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, # NUL
byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, # BKS
byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, # DLE
byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, byte 1, # CAN
' ' => byte 1,
'/' => byte 1,
16r7f=> byte 1,
* => byte 0
};
cmdokname(nil: ref Edit, elem: string): string
{
for(i := 0; i < len elem; i++)
if(int isfrog[elem[i]])
return "bad character in name";
return nil;
}
mkpart(name: string, start: big, end: big, changed: int): ref Part
{
p := ref Part;
p.name = name;
p.ctlname = name;
p.start = start;
p.end = end;
p.changed = changed;
p.ctlstart = big 0;
p.ctlend = big 0;
return p;
}
# plan9 partition table is first sector of the disk
rdpart(edit: ref Edit)
{
disk := edit.disk;
sys->seek(disk.fd, big disk.secsize, 0);
if(sys->readn(disk.fd, osecbuf, disk.secsize) != disk.secsize)
return;
osecbuf[disk.secsize] = byte 0;
secbuf[0:] = osecbuf;
for(i := 0; i < disk.secsize; i++)
if(secbuf[i] == byte 0)
break;
tab := string secbuf[0:i];
if(len tab < 4 || tab[0:4] != "part"){
sys->fprint(stderr, "no plan9 partition table found\n");
return;
}
waserr := 0;
(nline, lines) := sys->tokenize(tab, "\n");
for(i=0; i<nline; i++){
line := hd lines;
lines = tl lines;
if(len line < 4 || line[0:4] != "part"){
waserr = 1;
continue;
}
(nf, f) := sys->tokenize(line, " \t\r");
if(nf != 4 || hd f != "part"){
waserr = 1;
continue;
}
a := big hd tl tl f;
b := big hd tl tl tl f;
if(a >= b){
waserr = 1;
continue;
}
if((err := edit.addpart(mkpart(hd tl f, a, b, 0))) != nil) {
sys->fprint(stderr, "?%s: not continuing\n", err);
exits("partition");
}
}
if(waserr)
sys->fprint(stderr, "syntax error reading partition\n");
}
min(a, b: big): big
{
if(a < b)
return a;
return b;
}
autopart(edit: ref Edit)
{
if(len edit.part > 0) {
if(doauto)
sys->fprint(stderr, "partitions already exist; not repartitioning\n");
return;
}
secs := edit.disk.secs;
secsize := big edit.disk.secsize;
for(;;){
# compute total weights
totw := 0;
for(i:=0; i<len auto; i++){
if(auto[i].alloc==0 || auto[i].size != big 0)
continue;
totw += auto[i].weight;
}
if(totw == 0)
break;
if(secs <= big 0){
sys->fprint(stderr, "ran out of disk space during autopartition.\n");
return;
}
# assign any minimums for small disks
futz := 0;
for(i=0; i<len auto; i++){
if(auto[i].alloc==0 || auto[i].size != big 0)
continue;
s := (secs*big auto[i].weight)/big totw;
if(s < big auto[i].min/secsize){
auto[i].size = big auto[i].min/secsize;
secs -= auto[i].size;
futz = 1;
break;
}
}
if(futz)
continue;
# assign any maximums for big disks
futz = 0;
for(i=0; i<len auto; i++){
if(auto[i].alloc==0 || auto[i].size != big 0)
continue;
s := (secs*big auto[i].weight)/big totw;
if(auto[i].max != big 0 && s > auto[i].max/secsize){
auto[i].size = auto[i].max/secsize;
secs -= auto[i].size;
futz = 1;
break;
}
}
if(futz)
continue;
# finally, assign partition sizes according to weights
for(i=0; i<len auto; i++){
if(auto[i].alloc==0 || auto[i].size != big 0)
continue;
s := (secs*big auto[i].weight)/big totw;
auto[i].size = s;
# use entire disk even in face of rounding errors
secs -= auto[i].size;
totw -= auto[i].weight;
}
}
for(i:=0; i<len auto; i++)
if(auto[i].alloc)
sys->print("%s %bud\n", auto[i].name, auto[i].size);
s := big 0;
for(i=0; i<len auto; i++){
if(auto[i].alloc == 0)
continue;
if((err := edit.addpart(mkpart(auto[i].name, s, s+auto[i].size, 1))) != nil)
sys->fprint(stderr, "addpart %s: %s\n", auto[i].name, err);
s += auto[i].size;
}
}
restore(edit: ref Edit, ctlfd: ref Sys->FD)
{
offset := edit.disk.offset;
sys->fprint(stderr, "attempting to restore partitions to previous state\n");
if(sys->seek(edit.disk.wfd, big edit.disk.secsize, 0) != big 0){
sys->fprint(stderr, "cannot restore: error seeking on disk: %r\n");
exits("inconsistent");
}
if(sys->write(edit.disk.wfd, osecbuf, edit.disk.secsize) != edit.disk.secsize){
sys->fprint(stderr, "cannot restore: couldn't write old partition table to disk: %r\n");
exits("inconsistent");
}
if(ctlfd != nil){
for(i:=0; i<len edit.part; i++)
sys->fprint(ctlfd, "delpart %s", edit.part[i].name);
for(i=0; i<len opart; i++){
if(sys->fprint(ctlfd, "part %s %bd %bd", opart[i].name, opart[i].start+offset, opart[i].end+offset) < 0){
sys->fprint(stderr, "restored disk partition table but not kernel table; reboot\n");
exits("inconsistent");
}
}
}
exits("restored");
}
wrpart(edit: ref Edit)
{
disk := edit.disk;
secbuf[0:] = zeroes;
n := 0;
for(i:=0; i<len edit.part; i++){
a := sys->aprint("part %s %bd %bd\n",
edit.part[i].name, edit.part[i].start, edit.part[i].end);
if(n + len a > disk.secsize){
sys->fprint(stderr, "partition table bigger than sector (%d bytes)\n", disk.secsize);
exits("overflow");
}
secbuf[n:] = a;
n += len a;
}
if(sys->seek(disk.wfd, big disk.secsize, 0) != big disk.secsize){
sys->fprint(stderr, "error seeking to %d on disk: %r\n", disk.secsize);
exits("seek");
}
if(sys->write(disk.wfd, secbuf, disk.secsize) != disk.secsize){
sys->fprint(stderr, "error writing partition table to disk: %r\n");
restore(edit, nil);
}
if(edit.ctldiff(disk.ctlfd) < 0)
sys->fprint(stderr, "?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.
#
checkfat(disk: ref Disk)
{
buf := array[32] of byte;
if(sys->seek(disk.fd, big disk.secsize, 0) != big disk.secsize ||
sys->read(disk.fd, buf, len buf) < len buf)
return;
if(buf[0] != byte 16rEB || buf[1] != byte 16r3C || buf[2] != byte 16r90)
return;
sys->fprint(stderr,
"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");
}
exits(s: string)
{
if(s != nil)
raise "fail:"+s;
exit;
}