ref: f6dbd3d99325352b80e2ff6b0d13e8a1557369cb
dir: /sys/src/cmd/disk/prep/edit.c/
/*
* disk partition editor
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>
#include <disk.h>
#include "edit.h"
char*
getline(Edit *edit)
{
static int inited;
static Biobuf bin;
char *p;
int n;
if(!inited){
Binit(&bin, 0, OREAD);
inited = 1;
}
p = Brdline(&bin, '\n');
n = Blinelen(&bin);
if(p == nil || n < 1){
if(edit->changed)
fprint(2, "?warning: changes not written\n");
exits(0);
}
p[n - 1] = '\0';
while(isspace(*p))
p++;
return p;
}
Part*
findpart(Edit *edit, char *name)
{
int i;
for(i=0; i<edit->npart; i++)
if(strcmp(edit->part[i]->name, name) == 0)
return edit->part[i];
return nil;
}
static char*
okname(Edit *edit, char *name)
{
int i;
static char msg[100];
if(name[0] == '\0')
return "partition has no name";
// if(strlen(name) >= NAMELEN)
// return "name too long";
//
for(i=0; i<edit->npart; i++) {
if(strcmp(name, edit->part[i]->name) == 0) {
sprint(msg, "already have partition with name \"%s\"", name);
return msg;
}
}
return nil;
}
char*
addpart(Edit *edit, Part *p)
{
int i;
static char msg[100];
char *err;
if(err = okname(edit, p->name))
return err;
for(i=0; i<edit->npart; i++) {
if(p->start < edit->part[i]->end && edit->part[i]->start < p->end) {
sprint(msg, "\"%s\" %lld-%lld overlaps with \"%s\" %lld-%lld",
p->name, p->start, p->end,
edit->part[i]->name, edit->part[i]->start, edit->part[i]->end);
// return msg;
}
}
if(edit->npart >= nelem(edit->part))
return "too many partitions";
edit->part[i=edit->npart++] = p;
for(; i > 0 && p->start < edit->part[i-1]->start; i--) {
edit->part[i] = edit->part[i-1];
edit->part[i-1] = p;
}
if(p->changed)
edit->changed = 1;
return nil;
}
char*
delpart(Edit *edit, Part *p)
{
int i;
for(i=0; i<edit->npart; i++)
if(edit->part[i] == p)
break;
assert(i < edit->npart);
edit->npart--;
for(; i<edit->npart; i++)
edit->part[i] = edit->part[i+1];
edit->changed = 1;
return nil;
}
static char*
editdot(Edit *edit, int argc, char **argv)
{
char *err;
vlong ndot;
if(argc == 1) {
print("\t. %lld\n", edit->dot);
return nil;
}
if(argc > 2)
return "args";
if(err = parseexpr(argv[1], edit->dot, edit->end, edit->end, &ndot))
return err;
edit->dot = ndot;
return nil;
}
static char*
editadd(Edit *edit, int argc, char **argv)
{
char *name, *err, *q;
static char msg[100];
vlong start, end, maxend;
int i;
if(argc < 2)
return "args";
name = estrdup(argv[1]);
if((err = okname(edit, name)) || (err = edit->okname(edit, name)))
return err;
if(argc >= 3)
q = argv[2];
else {
fprint(2, "start %s: ", edit->unit);
q = getline(edit);
}
if(err = parseexpr(q, edit->dot, edit->end, edit->end, &start))
return err;
if(start < 0 || start >= edit->end)
return "start out of range";
for(i=0; i < edit->npart; i++) {
if(edit->part[i]->start <= start && start < edit->part[i]->end) {
sprint(msg, "start %s in partition \"%s\"", edit->unit, edit->part[i]->name);
return msg;
}
}
maxend = edit->end;
for(i=0; i < edit->npart; i++)
if(start < edit->part[i]->start && edit->part[i]->start < maxend)
maxend = edit->part[i]->start;
if(argc >= 4)
q = argv[3];
else {
fprint(2, "end [%lld..%lld] ", start, maxend);
q = getline(edit);
}
if(err = parseexpr(q, edit->dot, maxend, edit->end, &end))
return err;
if(start == end)
return "size zero partition";
if(end <= start || end > maxend)
return "end out of range";
if(argc > 4)
return "args";
if(err = edit->add(edit, name, start, end))
return err;
edit->dot = end;
return nil;
}
static char*
editdel(Edit *edit, int argc, char **argv)
{
Part *p;
if(argc != 2)
return "args";
if((p = findpart(edit, argv[1])) == nil)
return "no such partition";
return edit->del(edit, p);
}
static char *helptext =
". [newdot] - display or set value of dot\n"
"a name [start [end]] - add partition\n"
"d name - delete partition\n"
"h - print help message\n"
"p - print partition table\n"
"P - print commands to update sd(3) device\n"
"w - write partition table\n"
"q - quit\n";
static char*
edithelp(Edit *edit, int, char**)
{
print("%s", helptext);
if(edit->help)
return edit->help(edit);
return nil;
}
static char*
editprint(Edit *edit, int argc, char**)
{
vlong lastend;
int i;
Part **part;
if(argc != 1)
return "args";
lastend = 0;
part = edit->part;
for(i=0; i<edit->npart; i++) {
if(lastend < part[i]->start)
edit->sum(edit, nil, lastend, part[i]->start);
edit->sum(edit, part[i], part[i]->start, part[i]->end);
lastend = part[i]->end;
}
if(lastend < edit->end)
edit->sum(edit, nil, lastend, edit->end);
return nil;
}
char*
editwrite(Edit *edit, int argc, char**)
{
int i;
char *err;
if(argc != 1)
return "args";
if(edit->disk->rdonly)
return "read only";
err = edit->write(edit);
if(err)
return err;
for(i=0; i<edit->npart; i++)
edit->part[i]->changed = 0;
edit->changed = 0;
return nil;
}
static char*
editquit(Edit *edit, int argc, char**)
{
static int warned;
if(argc != 1) {
warned = 0;
return "args";
}
if(edit->changed && (!edit->warned || edit->lastcmd != 'q')) {
edit->warned = 1;
return "changes unwritten";
}
exits(0);
return nil; /* not reached */
}
char*
editctlprint(Edit *edit, int argc, char **)
{
if(argc != 1)
return "args";
if(edit->printctl)
edit->printctl(edit, 1);
else
ctldiff(edit, 1);
return nil;
}
typedef struct Cmd Cmd;
struct Cmd {
char c;
char *(*fn)(Edit*, int ,char**);
};
Cmd cmds[] = {
'.', editdot,
'a', editadd,
'd', editdel,
'?', edithelp,
'h', edithelp,
'P', editctlprint,
'p', editprint,
'w', editwrite,
'q', editquit,
};
void
runcmd(Edit *edit, char *cmd)
{
char *f[10], *err;
int i, nf;
while(*cmd && isspace(*cmd))
cmd++;
nf = tokenize(cmd, f, nelem(f));
if(nf >= 10) {
fprint(2, "?\n");
return;
}
if(nf < 1)
return;
if(strlen(f[0]) != 1) {
fprint(2, "?\n");
return;
}
err = nil;
for(i=0; i<nelem(cmds); i++) {
if(cmds[i].c == f[0][0]) {
err = cmds[i].fn(edit, nf, f);
break;
}
}
if(i == nelem(cmds)){
if(edit->ext)
err = edit->ext(edit, nf, f);
else
err = "unknown command";
}
if(err)
fprint(2, "?%s\n", err);
edit->lastcmd = f[0][0];
}
static Part*
ctlmkpart(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;
}
static void
rdctlpart(Edit *edit)
{
int i, nline, nf;
char *line[128];
char buf[4096];
vlong a, b;
char *f[5];
Disk *disk;
disk = edit->disk;
edit->nctlpart = 0;
seek(disk->ctlfd, 0, 0);
if(readn(disk->ctlfd, buf, sizeof buf) <= 0) {
return;
}
nline = getfields(buf, line, nelem(line), 1, "\n");
for(i=0; i<nline; i++){
if(strncmp(line[i], "part ", 5) != 0)
continue;
nf = getfields(line[i], f, nelem(f), 1, " \t\r");
if(nf != 4 || strcmp(f[0], "part") != 0)
break;
a = strtoll(f[2], 0, 0);
b = strtoll(f[3], 0, 0);
if(a >= b)
break;
/* only gather partitions contained in the disk partition we are editing */
if(a < disk->offset || disk->offset+disk->secs < b)
continue;
a -= disk->offset;
b -= disk->offset;
/* the partition we are editing does not count */
if(strcmp(f[1], disk->part) == 0)
continue;
if(edit->nctlpart >= nelem(edit->ctlpart)) {
fprint(2, "?too many partitions in ctl file\n");
exits("ctlpart");
}
edit->ctlpart[edit->nctlpart++] = ctlmkpart(f[1], a, b, 0);
}
}
static vlong
ctlstart(Part *p)
{
if(p->ctlstart)
return p->ctlstart;
return p->start;
}
static vlong
ctlend(Part *p)
{
if(p->ctlend)
return p->ctlend;
return p->end;
}
static int
areequiv(Part *p, Part *q)
{
if(p->ctlname[0]=='\0' || q->ctlname[0]=='\0')
return 0;
return strcmp(p->ctlname, q->ctlname) == 0
&& ctlstart(p) == ctlstart(q) && ctlend(p) == ctlend(q);
}
static void
unchange(Edit *edit, Part *p)
{
int i;
Part *q;
for(i=0; i<edit->nctlpart; i++) {
q = edit->ctlpart[i];
if(p->start <= q->start && q->end <= p->end) {
q->changed = 0;
}
}
assert(p->changed == 0);
}
int
ctldiff(Edit *edit, int ctlfd)
{
int i, j, waserr;
Part *p;
vlong offset;
rdctlpart(edit);
/* everything is bogus until we prove otherwise */
for(i=0; i<edit->nctlpart; i++)
edit->ctlpart[i]->changed = 1;
/*
* partitions with same info have not changed,
* and neither have partitions inside them.
*/
for(i=0; i<edit->nctlpart; i++)
for(j=0; j<edit->npart; j++)
if(areequiv(edit->ctlpart[i], edit->part[j])) {
unchange(edit, edit->ctlpart[i]);
break;
}
waserr = 0;
/*
* delete all the changed partitions except data (we'll add them back if necessary)
*/
for(i=0; i<edit->nctlpart; i++) {
p = edit->ctlpart[i];
if(p->changed)
if(fprint(ctlfd, "delpart %s\n", p->ctlname)<0) {
fprint(2, "delpart failed: %s: %r\n", p->ctlname);
waserr = -1;
}
}
/*
* add all the partitions from the real list;
* this is okay since adding a parition with
* information identical to what is there is a no-op.
*/
offset = edit->disk->offset;
for(i=0; i<edit->npart; i++) {
p = edit->part[i];
if(p->ctlname[0]) {
if(fprint(ctlfd, "part %s %lld %lld\n", p->ctlname, offset+ctlstart(p), offset+ctlend(p)) < 0) {
fprint(2, "adding part failed: %s: %r\n", p->ctlname);
waserr = -1;
}
}
}
return waserr;
}
void*
emalloc(ulong sz)
{
void *v;
v = malloc(sz);
if(v == nil)
sysfatal("malloc %lud fails", sz);
memset(v, 0, sz);
return v;
}
char*
estrdup(char *s)
{
s = strdup(s);
if(s == nil)
sysfatal("strdup (%.10s) fails", s);
return s;
}