From f188f2f0738b4888130f9f07181f4cc367afb2d1 Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Sun, 18 Nov 2012 12:53:31 +0100 Subject: hjfs: eleminate seek syscalls reduce syscalls by using pread/pwrite instead of seek/read/write. --- sys/src/cmd/hjfs/dev.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/sys/src/cmd/hjfs/dev.c b/sys/src/cmd/hjfs/dev.c index 45c3a9e09..4826b4bdd 100644 --- a/sys/src/cmd/hjfs/dev.c +++ b/sys/src/cmd/hjfs/dev.c @@ -30,20 +30,27 @@ devwork(void *v) b->error = Einval; goto reply; } - seek(d->fd, b->off * BLOCK, 0); b->error = nil; if(b->op & BWRITE){ memset(buf, 0, sizeof(buf)); pack(b, buf); - if(write(d->fd, buf, BLOCK) < BLOCK){ + if(pwrite(d->fd, buf, BLOCK, b->off*BLOCK) < BLOCK){ dprint("hjfs: write: %r\n"); b->error = Eio; } }else{ - if(readn(d->fd, buf, BLOCK) < 0){ - dprint("hjfs: read: %r\n"); + int n, m; + + for(n = 0; n < BLOCK; n += m){ + m = pread(d->fd, buf+n, BLOCK-n, b->off*BLOCK+n); + if(m < 0) + dprint("hjfs: read: %r\n"); + if(m <= 0) + break; + } + if(n < BLOCK) b->error = Eio; - }else + else unpack(b, buf); } reply: -- cgit v1.2.3