diff options
| -rw-r--r-- | sys/src/cmd/hjfs/buf.c | 75 |
1 files changed, 39 insertions, 36 deletions
diff --git a/sys/src/cmd/hjfs/buf.c b/sys/src/cmd/hjfs/buf.c index e52c250eb..1850bf6db 100644 --- a/sys/src/cmd/hjfs/buf.c +++ b/sys/src/cmd/hjfs/buf.c @@ -54,14 +54,26 @@ delayreq(BufReq req, BufReq **first, BufReq **last) BufReq *r; r = emalloc(sizeof(*r)); - memcpy(r, &req, sizeof(*r)); + *r = req; r->next = nil; if(*first == nil) - *first = *last = r; - else{ + *first = r; + else (*last)->next = r; - *last = r; - } + *last = r; +} + +static BufReq +undelayreq(BufReq **first, BufReq **last) +{ + BufReq r; + + r = **first; + free(*first); + *first = r.next; + if(r.next == nil) + *last = nil; + return r; } static void @@ -81,7 +93,7 @@ givebuf(BufReq req, Buf *b) { Buf *c, *l; - assert(!b->busy); +again: if(req.d == b->d && req.off == b->off){ markbusy(b); send(req.resp, &b); @@ -90,19 +102,30 @@ givebuf(BufReq req, Buf *b) l = &req.d->buf[req.off & BUFHASH]; for(c = l->dnext; c != l; c = c->dnext) if(c->off == req.off){ - if(c->busy){ + if(c->busy) delayreq(req, &c->next, &c->last); - return; + else{ + markbusy(c); + send(req.resp, &c); } - markbusy(c); - send(req.resp, &c); - return; + if(b->next == nil) + return; + req = undelayreq(&b->next, &b->last); + goto again; } + if(b->next != nil){ + givebuf(undelayreq(&b->next, &b->last), b); + b = bfree.fnext; + } + if(b == &bfree){ + delayreq(req, &freereq, &freereqlast); + return; + } markbusy(b); - if(b->op & BDELWRI){ + if(b->d != nil && b->op & BDELWRI){ + delayreq(req, &b->next, &b->last); b->op &= ~BDELWRI; b->op |= BWRITE; - delayreq(req, &b->next, &b->last); b->resp = putb; work(b->d, b); return; @@ -120,27 +143,7 @@ givebuf(BufReq req, Buf *b) static void handleget(BufReq req) { - Buf *b; - - b = bfree.fnext; - if(b == &bfree){ - delayreq(req, &freereq, &freereqlast); - return; - } - givebuf(req, b); -} - -static void -undelayreq(Buf *b, BufReq **first, BufReq **last) -{ - BufReq *r; - - r = *first; - *first = r->next; - if(*last == r) - *last = nil; - givebuf(*r, b); - free(r); + givebuf(req, bfree.fnext); } static void @@ -161,9 +164,9 @@ handleput(Buf *b) b->op &= ~BWRITE; markfree(b); if(b->next != nil) - undelayreq(b, &b->next, &b->last); + givebuf(undelayreq(&b->next, &b->last), b); else if(freereq != nil) - undelayreq(b, &freereq, &freereqlast); + givebuf(undelayreq(&freereq, &freereqlast), b); } static void |