diff options
| -rw-r--r-- | sys/src/9/port/devmnt.c | 70 |
1 files changed, 41 insertions, 29 deletions
diff --git a/sys/src/9/port/devmnt.c b/sys/src/9/port/devmnt.c index 2b6610afc..91d6ad2f9 100644 --- a/sys/src/9/port/devmnt.c +++ b/sys/src/9/port/devmnt.c @@ -634,32 +634,11 @@ static long mntread(Chan *c, void *buf, long n, vlong off) { uchar *p, *e; - int nc, cache, isdir, dirlen; - - isdir = 0; - cache = c->flag & CCACHE; - if(c->qid.type & QTDIR) { - cache = 0; - isdir = 1; - } + int dirlen; p = buf; - if(cache) { - nc = cread(c, buf, n, off); - if(nc > 0) { - n -= nc; - if(n == 0) - return nc; - p += nc; - off += nc; - } - n = mntrdwr(Tread, c, p, n, off); - cupdate(c, p, n, off); - return n + nc; - } - - n = mntrdwr(Tread, c, buf, n, off); - if(isdir) { + n = mntrdwr(Tread, c, p, n, off); + if(c->qid.type & QTDIR) { for(e = &p[n]; p+BIT16SZ < e; p += dirlen){ dirlen = BIT16SZ+GBIT16(p); if(p+dirlen > e) @@ -695,6 +674,14 @@ mntrdwr(int type, Chan *c, void *buf, long n, vlong off) if(c->qid.type & QTDIR) cache = 0; for(;;) { + if(cache && type == Tread) { + nr = cread(c, (uchar*)uba, n, off); + if(nr > 0) { + nreq = nr; + goto Next; + } + } + r = mntralloc(c, m->msize); if(waserror()) { mntfree(r); @@ -714,13 +701,39 @@ mntrdwr(int type, Chan *c, void *buf, long n, vlong off) if(nr > nreq) nr = nreq; + if(cache) { + /* + * note that we cannot update the cache from uba as + * the user could change its contents from another + * process before the data gets copied to the cached. + */ + if(type == Tread) { + ulong nc, nn; + Block *b; + + nc = 0; + for(b = r->b; b != nil; b = b->next) { + nn = BLEN(b); + if(nc+nn > nr) + nn = nr - nc; + cupdate(c, b->rp, nn, off + nc); + nc += nn; + if(nc >= nr) + break; + } + } else { + if(convM2S(r->rpc, r->rpclen, &r->request) == 0) + panic("convM2S"); + cwrite(c, (uchar*)r->request.data, nr, off); + } + } + if(type == Tread) r->b = bl2mem((uchar*)uba, r->b, nr); - else if(cache) - cwrite(c, (uchar*)uba, nr, off); - - poperror(); mntfree(r); + poperror(); + + Next: off += nr; uba += nr; cnt += nr; @@ -807,7 +820,6 @@ mountio(Mnt *m, Mntrpc *r) up->text, up->pid, n, r->request.tag, r->request.fid, r->request.type); error(Emountrpc); } - if(devtab[m->c->type]->write(m->c, r->rpc, n, 0) != n) error(Emountrpc); |