xfnw/plan9fox
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

hjfs: fix getfree() races, fix very rare buf leak in deltraverse()

Browse source
This commit is contained in:
cinap_lenrek 2012-11-16 22:57:43 +01:00
parent 84ddc4cd4b
commit 08cd0ea8d4
1 changed files with 40 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

64
sys/src/cmd/hjfs/fs1.c
View file

@ -62,44 +62,57 @@ int
getfree(Fs *fs, uvlong *r)
{
Dev *d;
Buf *b, *c;
uvlong i, l;
Buf *b;
uvlong i, l, e;
int j, have;
d = fs->d;
while(nbrecv(fs->freelist, &l) > 0){
i = fs->fstart + l / REFPERBLK;
j = l % REFPERBLK;
b = getbuf(d, i, TREF, 0);
if(b != nil){
if(b->refs[j] == 0){
b->refs[j] = 1;
*r = l;
goto found;
}
putbuf(b);
}
}
b = getbuf(d, SUPERBLK, TSUPERBLOCK, 0);
if(b == nil)
return -1;
if(nbrecv(fs->freelist, r) > 0)
goto found;
e = b->sb.fend;
putbuf(b);
have = 0;
for(i = b->sb.fstart, l = 0; i < b->sb.fend; i++){
c = getbuf(d, i, TREF, 0);
if(c == nil){
putbuf(b);
return -1;
for(l = 0, i = fs->fstart; i < e; i++){
b = getbuf(d, i, TREF, 0);
if(b == nil){
l += REFPERBLK;
continue;
}
for(j = 0; j < REFPERBLK; j++, l++)
if(c->refs[j] == 0){
if(b->refs[j] == 0){
if(!have){
have = 1;
b->refs[j] = 1;
*r = l;
}else if(nbsend(fs->freelist, &l) <= 0){
putbuf(c);
goto done;
have = 1;
}
else if(nbsend(fs->freelist, &l) <= 0)
goto found;
}
putbuf(c);
}
done:
if(!have){
werrstr("disk full");
return -1;
if(have)
goto found;
putbuf(b);
}
werrstr("disk full");
return -1;
found:
b->op |= BDELWRI;
putbuf(b);
if(chref(fs, *r, 1) < 0)
return -1;
return 1;
}
@ -854,14 +867,17 @@ deltraverse(Fs *fs, Del *p, Buf *b, Del **last)
Del *dd;
frb = b == nil;
if(b == nil){
if(frb){
b = getbuf(fs->d, p->blk, TDENTRY, 0);
if(b == nil)
return -1;
}
d = getdent(p, b);
if(d == nil)
if(d == nil){
if(frb)
putbuf(b);
return -1;
}
s = d->size;
for(i = 0; i < s; i++){
rc = getblk(fs, p, b, i, &r, GBREAD);