ref: 985b2457cda207c2c65edeb647aedbb6e92dac46
dir: /sys/src/cmd/disk/kfs/sub.c/
#include "all.h"
Lock wpathlock;
struct {
Lock flock;
File* ffree; /* free file structures */
Wpath* wfree;
} suballoc;
enum{
Finc= 128, /* allocation chunksize for files */
Fmax= 10000, /* maximum file structures to be allocated */
Winc= 8*128, /* allocation chunksize for wpath */
Wmax= 8*10000, /* maximum wpath structures to be allocated */
};
Filsys*
fsstr(char *p)
{
Filsys *fs;
for(fs=filesys; fs->name; fs++)
if(strcmp(fs->name, p) == 0)
return fs;
return 0;
}
void
fileinit(Chan *cp)
{
File *f;
Tlock *t;
loop:
lock(&cp->flock);
f = cp->flist;
if(!f) {
unlock(&cp->flock);
return;
}
cp->flist = f->next;
unlock(&cp->flock);
qlock(f);
if(t = f->tlock) {
t->time = 0;
f->tlock = 0;
}
if(f->open & FREMOV)
doremove(f, 0);
freewp(f->wpath);
f->open = 0;
f->cp = 0;
qunlock(f);
goto loop;
}
/*
* returns a locked file structure
*/
File*
filep(Chan *cp, int fid, int flag)
{
File *f, *prev;
if(fid == NOF)
return 0;
loop:
lock(&cp->flock);
for(prev=0,f=cp->flist; f; prev=f,f=f->next) {
if(f->fid != fid)
continue;
if(prev) {
prev->next = f->next;
f->next = cp->flist;
cp->flist = f;
}
goto out;
}
if(flag) {
f = newfp(cp);
if(f) {
f->fid = fid;
goto out;
}
}
else print("cannot find %p.%ud (list=%p)\n", cp, fid, cp->flist);
unlock(&cp->flock);
return 0;
out:
unlock(&cp->flock);
qlock(f);
if(f->fid != fid) {
qunlock(f);
goto loop;
}
return f;
}
void
sublockinit(void)
{
lock(&suballoc.flock);
lock(&wpathlock);
conf.nfile = 0;
conf.nwpath = 0;
unlock(&suballoc.flock);
unlock(&wpathlock);
}
/*
* always called with cp->flock locked
*/
File*
newfp(Chan *cp)
{
File *f, *e;
retry:
lock(&suballoc.flock);
f = suballoc.ffree;
if(f != nil){
suballoc.ffree = f->list;
unlock(&suballoc.flock);
f->list = 0;
f->cp = cp;
f->next = cp->flist;
f->wpath = 0;
f->tlock = 0;
f->dslot = 0;
f->doffset = 0;
f->uid = 0;
f->cuid = 0;
cp->flist = f;
return f;
}
unlock(&suballoc.flock);
if(conf.nfile > Fmax){
print("%d: out of files\n", cp->chan);
return 0;
}
/*
* create a few new files
*/
f = malloc(Finc*sizeof(*f));
memset(f, 0, Finc*sizeof(*f));
lock(&suballoc.flock);
for(e = f+Finc; f < e; f++){
qlock(f);
qunlock(f);
f->list = suballoc.ffree;
suballoc.ffree = f;
}
conf.nfile += Finc;
unlock(&suballoc.flock);
goto retry;
}
void
freefp(File *fp)
{
Chan *cp;
File *f, *prev;
if(!fp || !(cp = fp->cp))
return;
authfree(fp);
lock(&cp->flock);
for(prev=0,f=cp->flist; f; prev=f,f=f->next) {
if(f != fp)
continue;
if(prev)
prev->next = f->next;
else
cp->flist = f->next;
f->cp = 0;
lock(&suballoc.flock);
f->list = suballoc.ffree;
suballoc.ffree = f;
unlock(&suballoc.flock);
break;
}
unlock(&cp->flock);
}
Wpath*
newwp(void)
{
Wpath *w, *e;
retry:
lock(&wpathlock);
w = suballoc.wfree;
if(w != nil){
suballoc.wfree = w->list;
unlock(&wpathlock);
memset(w, 0, sizeof(*w));
w->refs = 1;
w->up = 0;
return w;
}
unlock(&wpathlock);
if(conf.nwpath > Wmax){
print("out of wpaths\n");
return 0;
}
/*
* create a few new wpaths
*/
w = malloc(Winc*sizeof(*w));
memset(w, 0, Winc*sizeof(*w));
lock(&wpathlock);
for(e = w+Winc; w < e; w++){
w->list = suballoc.wfree;
suballoc.wfree = w;
}
conf.nwpath += Winc;
unlock(&wpathlock);
goto retry;
}
/*
* increment the references for the whole path
*/
Wpath*
getwp(Wpath *w)
{
Wpath *nw;
lock(&wpathlock);
for(nw = w; nw; nw=nw->up)
nw->refs++;
unlock(&wpathlock);
return w;
}
/*
* decrement the reference for each element of the path
*/
void
freewp(Wpath *w)
{
lock(&wpathlock);
for(; w; w=w->up){
w->refs--;
if(w->refs == 0){
w->list = suballoc.wfree;
suballoc.wfree = w;
}
}
unlock(&wpathlock);
}
/*
* decrement the reference for just this element
*/
void
putwp(Wpath *w)
{
lock(&wpathlock);
w->refs--;
if(w->refs == 0){
w->list = suballoc.wfree;
suballoc.wfree = w;
}
unlock(&wpathlock);
}
int
iaccess(File *f, Dentry *d, int m)
{
if(wstatallow)
return 0;
/*
* owner is next
*/
if(f->uid == d->uid)
if((m<<6) & d->mode)
return 0;
/*
* group membership is hard
*/
if(ingroup(f->uid, d->gid))
if((m<<3) & d->mode)
return 0;
/*
* other access for everyone except members of group 9999
*/
if(m & d->mode){
/*
* walk directories regardless.
* otherwise its impossible to get
* from the root to noworld's directories.
*/
if((d->mode & DDIR) && (m == DEXEC))
return 0;
if(!ingroup(f->uid, 9999))
return 0;
}
return 1;
}
Tlock*
tlocked(Iobuf *p, Dentry *d)
{
Tlock *t, *t1;
long qpath, tim;
Device dev;
tim = time(0);
qpath = d->qid.path;
dev = p->dev;
t1 = 0;
for(t=tlocks+NTLOCK-1; t>=tlocks; t--) {
if(t->qpath == qpath)
if(t->time >= tim)
if(devcmp(t->dev, dev) == 0)
return 0; /* its locked */
if(!t1 && t->time < tim)
t1 = t; /* steal first lock */
}
if(t1) {
t1->dev = dev;
t1->qpath = qpath;
t1->time = tim + TLOCK;
}
/* botch
* out of tlock nodes simulates
* a locked file
*/
return t1;
}
Qid
newqid(Device dev)
{
Iobuf *p;
Superb *sb;
Qid qid;
p = getbuf(dev, superaddr(dev), Bread|Bmod);
if(!p || checktag(p, Tsuper, QPSUPER))
panic("newqid: super block");
sb = (Superb*)p->iobuf;
sb->qidgen++;
qid.path = sb->qidgen;
qid.vers = 0;
qid.type = 0;
putbuf(p);
return qid;
}
/*
* what are legal characters in a name?
* only disallow control characters.
* a) utf avoids control characters.
* b) '/' may not be the separator
*/
int
checkname(char *n)
{
int i, c;
for(i=0; i<NAMELEN; i++) {
c = *n & 0xff;
if(c == 0) {
if(i == 0)
return 1;
memset(n, 0, NAMELEN-i);
return 0;
}
if(c <= 040)
return 1;
n++;
}
return 1; /* too long */
}
void
bfree(Device dev, long addr, int d)
{
Iobuf *p;
long a;
int i;
if(!addr)
return;
if(d > 0) {
d--;
p = getbuf(dev, addr, Bread);
if(p) {
for(i=INDPERBUF-1; i>=0; i--) {
a = ((long*)p->iobuf)[i];
bfree(dev, a, d);
}
putbuf(p);
}
}
/*
* stop outstanding i/o
*/
p = getbuf(dev, addr, Bprobe);
if(p) {
p->flags &= ~(Bmod|Bimm);
putbuf(p);
}
/*
* dont put written worm
* blocks into free list
*/
if(nofree(dev, addr))
return;
p = getbuf(dev, superaddr(dev), Bread|Bmod);
if(!p || checktag(p, Tsuper, QPSUPER))
panic("bfree: super block");
addfree(dev, addr, (Superb*)p->iobuf);
putbuf(p);
}
long
balloc(Device dev, int tag, long qid)
{
Iobuf *bp, *p;
Superb *sb;
long a;
int n;
p = getbuf(dev, superaddr(dev), Bread|Bmod);
if(!p || checktag(p, Tsuper, QPSUPER))
panic("balloc: super block");
sb = (Superb*)p->iobuf;
loop:
n = --sb->fbuf.nfree;
sb->tfree--;
if(n < 0 || n >= FEPERBUF)
panic("balloc: bad freelist");
a = sb->fbuf.free[n];
if(n <= 0) {
if(a == 0) {
sb->tfree = 0;
sb->fbuf.nfree = 1;
if(devgrow(dev, sb))
goto loop;
putbuf(p);
return 0;
}
bp = getbuf(dev, a, Bread);
if(!bp || checktag(bp, Tfree, QPNONE)) {
if(bp)
putbuf(bp);
putbuf(p);
return 0;
}
memmove(&sb->fbuf, bp->iobuf, (FEPERBUF+1)*sizeof(long));
putbuf(bp);
}
bp = getbuf(dev, a, Bmod);
memset(bp->iobuf, 0, RBUFSIZE);
settag(bp, tag, qid);
if(tag == Tind1 || tag == Tind2 || tag == Tdir)
bp->flags |= Bimm;
putbuf(bp);
putbuf(p);
return a;
}
void
addfree(Device dev, long addr, Superb *sb)
{
int n;
Iobuf *p;
if(addr >= sb->fsize){
print("addfree: bad addr %lux\n", addr);
return;
}
n = sb->fbuf.nfree;
if(n < 0 || n > FEPERBUF)
panic("addfree: bad freelist");
if(n >= FEPERBUF) {
p = getbuf(dev, addr, Bmod);
if(p == 0)
panic("addfree: getbuf");
memmove(p->iobuf, &sb->fbuf, (FEPERBUF+1)*sizeof(long));
settag(p, Tfree, QPNONE);
putbuf(p);
n = 0;
}
sb->fbuf.free[n++] = addr;
sb->fbuf.nfree = n;
sb->tfree++;
if(addr >= sb->fsize)
sb->fsize = addr+1;
}
int
Cfmt(Fmt *f1)
{
Chan *cp;
cp = va_arg(f1->args, Chan*);
return fmtprint(f1, "C%d.%.3d", cp->type, cp->chan);
}
int
Dfmt(Fmt *f1)
{
Device d;
d = va_arg(f1->args, Device);
return fmtprint(f1, "D%d.%d.%d.%d", d.type, d.ctrl, d.unit, d.part);
}
int
Afmt(Fmt *f1)
{
Filta a;
a = va_arg(f1->args, Filta);
return fmtprint(f1, "%6lud %6lud %6lud",
fdf(a.f->filter[0], a.scale*60),
fdf(a.f->filter[1], a.scale*600),
fdf(a.f->filter[2], a.scale*6000));
}
int
Gfmt(Fmt *f1)
{
int t;
t = va_arg(f1->args, int);
if(t >= 0 && t < MAXTAG)
return fmtstrcpy(f1, tagnames[t]);
else
return fmtprint(f1, "<badtag %d>", t);
}
void
formatinit(void)
{
fmtinstall('C', Cfmt); /* print channels */
fmtinstall('D', Dfmt); /* print devices */
fmtinstall('A', Afmt); /* print filters */
fmtinstall('G', Gfmt); /* print tags */
fmtinstall('T', Tfmt); /* print times */
fmtinstall('O', ofcallfmt); /* print old fcalls */
}
int
devcmp(Device d1, Device d2)
{
if(d1.type == d2.type)
if(d1.ctrl == d2.ctrl)
if(d1.unit == d2.unit)
if(d1.part == d2.part)
return 0;
return 1;
}
void
rootream(Device dev, long addr)
{
Iobuf *p;
Dentry *d;
p = getbuf(dev, addr, Bmod|Bimm);
memset(p->iobuf, 0, RBUFSIZE);
settag(p, Tdir, QPROOT);
d = getdir(p, 0);
strcpy(d->name, "/");
d->uid = -1;
d->gid = -1;
d->mode = DALLOC | DDIR | 0775;
d->qid = QID9P1(QPROOT|QPDIR,0);
d->atime = time(0);
d->mtime = d->atime;
putbuf(p);
}
int
superok(Device dev, long addr, int set)
{
Iobuf *p;
Superb *s;
int ok;
p = getbuf(dev, addr, Bread|Bmod|Bimm);
s = (Superb*)p->iobuf;
ok = s->fsok;
s->fsok = set;
putbuf(p);
return ok;
}
void
superream(Device dev, long addr)
{
Iobuf *p;
Superb *s;
long i;
p = getbuf(dev, addr, Bmod|Bimm);
memset(p->iobuf, 0, RBUFSIZE);
settag(p, Tsuper, QPSUPER);
s = (Superb*)p->iobuf;
s->fstart = 1;
s->fsize = devsize(dev);
s->fbuf.nfree = 1;
s->qidgen = 10;
for(i=s->fsize-1; i>=addr+2; i--)
addfree(dev, i, s);
putbuf(p);
}
/*
* returns 1 if n is prime
* used for adjusting lengths
* of hashing things.
* there is no need to be clever
*/
int
prime(long n)
{
long i;
if((n%2) == 0)
return 0;
for(i=3;; i+=2) {
if((n%i) == 0)
return 0;
if(i*i >= n)
return 1;
}
}
void
hexdump(void *a, int n)
{
char s1[30], s2[4];
uchar *p;
int i;
p = a;
s1[0] = 0;
for(i=0; i<n; i++) {
sprint(s2, " %.2ux", p[i]);
strcat(s1, s2);
if((i&7) == 7) {
print("%s\n", s1);
s1[0] = 0;
}
}
if(s1[0])
print("%s\n", s1);
}
long
qidpathgen(Device *dev)
{
Iobuf *p;
Superb *sb;
long path;
p = getbuf(*dev, superaddr((*dev)), Bread|Bmod);
if(!p || checktag(p, Tsuper, QPSUPER))
panic("newqid: super block");
sb = (Superb*)p->iobuf;
sb->qidgen++;
path = sb->qidgen;
putbuf(p);
return path;
}