1994/0611/port/sysfile.c (diff list | history)

port/sysfile.c on 1990/0227
1990/0227		#include "u.h"
1992/0321		#include "../port/lib.h"
1990/0227		#include "mem.h" #include "dat.h" #include "fns.h"
1992/0111		#include "../port/error.h"
1990/0227		/* * The sys*() routines needn't poperror() as they return directly to syscall(). */ int
1991/0705		newfd(Chan *c)
1990/0227		{
1993/0501		Fgrp *f = up->fgrp;
1990/0227		int i;
1991/0705		lock(f);
1990/0227		for(i=0; i<NFD; i++)
1991/0705		if(f->fd[i] == 0){ if(i > f->maxfd) f->maxfd = i; f->fd[i] = c; unlock(f);
1990/0227		return i; }
1991/0705		unlock(f);
1992/0114		exhausted("file descriptors");
1992/0720		return 0;
1990/0227		} Chan*
1992/0825		fdtochan(int fd, int mode, int chkmnt, int iref)
1990/0227		{ Chan *c;
1992/0825		Fgrp *f;
1990/0227
1991/0904		c = 0;
1993/0501		f = up->fgrp;
1992/0825		lock(f); if(fd<0 || NFD<=fd || (c = f->fd[fd])==0) { unlock(f);
1990/11211		error(Ebadfd);
1992/0825		} if(iref) incref(c); unlock(f); if(chkmnt && (c->flag&CMSG)) { if(iref) close(c);
1992/0114		error(Ebadusefd);
1992/0825		}
1990/1009		if(mode<0 || c->mode==ORDWR)
1990/0227		return c;
1992/0825		if((mode&OTRUNC) && c->mode==OREAD) { if(iref) close(c);
1990/11211		error(Ebadusefd);
1992/0825		} if((mode&~OTRUNC) != c->mode) { if(iref) close(c);
1991/1011		error(Ebadusefd);
1992/0825		}
1990/0227		return c; } int openmode(ulong o) {
1990/08141		if(o >= (OTRUNC|OCEXEC|ORCLOSE|OEXEC))
1990/11211		error(Ebadarg);
1990/08141		o &= ~(OTRUNC|OCEXEC|ORCLOSE);
1990/0227		if(o > OEXEC)
1991/1018		error(Ebadarg);
1990/0227		if(o == OEXEC) return OREAD; return o; } long
1994/0321		sysfd2path(ulong *arg)
1993/1004		{ Chan *c; validaddr(arg[1], 1, 0); if(vmemchr((char*)arg[1], '\0', arg[2]) == 0) error(Ebadarg); c = fdtochan(arg[0], -1, 0, 0);
1994/0611		/* If we used open the chan will be at the first element * of a union rather than the mhead of the union. undomount * will make it look like we used Atodir rather than Aopen. */ if(c->qid.path & CHDIR) c = undomount(c);
1993/1004		ptpath(c->path, (char*)arg[1], arg[2]); return 0; } long
1990/1009		syspipe(ulong *arg) { int fd[2]; Chan *c[2]; Dev *d;
1993/0501		Fgrp *f = up->fgrp;
1990/1009		validaddr(arg[0], 2*BY2WD, 1); evenaddr(arg[0]); d = &devtab[devno('|', 0)];
1993/0501		c[0] = namec("#|", Atodir, 0, 0);
1990/1009		c[1] = 0; fd[0] = -1; fd[1] = -1; if(waserror()){ close(c[0]); if(c[1]) close(c[1]); if(fd[0] >= 0)
1991/0705		f->fd[fd[0]]=0;
1990/1009		if(fd[1] >= 0)
1991/0705		f->fd[fd[1]]=0;
1990/1009		nexterror(); }
1993/0501		c[1] = clone(c[0], 0); walk(c[0], "data", 1); walk(c[1], "data1", 1);
1990/1009		c[0] = (*d->open)(c[0], ORDWR); c[1] = (*d->open)(c[1], ORDWR);
1991/0705		fd[0] = newfd(c[0]); fd[1] = newfd(c[1]);
1990/1009		((long*)arg[0])[0] = fd[0]; ((long*)arg[0])[1] = fd[1]; poperror(); return 0; } long
1990/0227		sysdup(ulong *arg) { int fd; Chan *c, *oc;
1993/0501		Fgrp *f = up->fgrp;
1990/0227		/* * Close after dup'ing, so date > #d/1 works */
1992/0825		c = fdtochan(arg[0], -1, 0, 1);
1990/0227		fd = arg[1];
1991/0221		if(fd != -1){
1992/0825		if(fd<0 || NFD<=fd) { close(c);
1991/0221		error(Ebadfd);
1992/0825		}
1991/0705		lock(f); if(fd > f->maxfd) f->maxfd = fd;
1992/0825
1991/0705		oc = f->fd[fd]; f->fd[fd] = c; unlock(f); if(oc) close(oc);
1991/0706		}else{
1991/0705		if(waserror()) { close(c); nexterror(); } fd = newfd(c); poperror();
1990/0227		}
1991/0705
1990/0227		return fd; } long sysopen(ulong *arg) { int fd;
1991/0705		Chan *c = 0;
1990/0227		openmode(arg[1]); /* error check only */
1991/0706		if(waserror()){
1991/0705		if(c) close(c); nexterror(); }
1990/0227		validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aopen, arg[1], 0);
1991/0705		fd = newfd(c); poperror();
1990/0227		return fd; } void
1991/0705		fdclose(int fd, int flag)
1990/0227		{ int i;
1991/0705		Chan *c;
1993/0501		Fgrp *f = up->fgrp;
1990/0227
1991/0705		lock(f); c = f->fd[fd];
1992/0817		if(c == 0){ /* can happen for users with shared fd tables */ unlock(f); return; }
1991/0705		if(flag){ if(c==0 || !(c->flag&flag)){ unlock(f); return; } } f->fd[fd] = 0; if(fd == f->maxfd) for(i=fd; --i>=0 && f->fd[i]==0; ) f->maxfd = i; unlock(f); close(c);
1990/0227		} long sysclose(ulong *arg) {
1992/0825		fdtochan(arg[0], -1, 0, 0);
1991/0705		fdclose(arg[0], 0);
1990/0227		return 0; } long unionread(Chan *c, void *va, long n) { long nr;
1992/0720		Chan *nc; Pgrp *pg;
1990/0227
1993/0501		pg = up->pgrp;
1993/0318		rlock(&pg->ns);
1991/1011		for(;;) { if(waserror()) {
1993/0318		runlock(&pg->ns);
1991/1011		nexterror(); }
1993/0318		nc = clone(c->mnt->to, 0);
1991/1011		poperror();
1992/0720		if(c->mountid != c->mnt->mountid) {
1993/0318		pprint("unionread: changed underfoot?\n"); runlock(&pg->ns);
1991/1011		close(nc); return 0; }
1993/0318		/* Error causes component of union to be skipped */
1992/0720		if(waserror()) {
1991/1011		close(nc);
1992/0720		goto next;
1991/1011		} nc = (*devtab[nc->type].open)(nc, OREAD); nc->offset = c->offset; nr = (*devtab[nc->type].read)(nc, va, n, nc->offset);
1993/0318		/* devdirread e.g. changes it */
1991/1011		c->offset = nc->offset; poperror();
1990/0227		close(nc);
1991/1011		if(nr > 0) {
1993/0318		runlock(&pg->ns);
1991/1011		return nr; }
1992/0720		/* Advance to next element */ next:
1993/0318		c->mnt = c->mnt->next;
1991/1011		if(c->mnt == 0) break; c->mountid = c->mnt->mountid; c->offset = 0;
1990/0227		}
1993/0318		runlock(&pg->ns);
1991/1011		return 0;
1990/0227		} long
1994/0405		sysread9p(ulong *arg) { int dir; long n; Chan *c; validaddr(arg[1], arg[2], 1); c = fdtochan(arg[0], OREAD, 1, 1); if(waserror()) { close(c); nexterror(); } n = arg[2]; dir = c->qid.path&CHDIR; if(dir) { n -= n%DIRLEN; if(c->offset%DIRLEN || n==0) error(Etoosmall); } if(dir && c->mnt) n = unionread(c, (void*)arg[1], n); else if(devchar[c->type] != L'M') n = (*devtab[c->type].read)(c, (void*)arg[1], n, c->offset); else n = mntread9p(c, (void*)arg[1], n, c->offset); lock(c); c->offset += n; unlock(c); poperror(); close(c); return n; } long
1990/0227		sysread(ulong *arg) {
1992/0825		int dir;
1990/0227		long n;
1992/0825		Chan *c;
1990/0227
1990/1004		validaddr(arg[1], arg[2], 1);
1992/0825		c = fdtochan(arg[0], OREAD, 1, 1); if(waserror()) { close(c);
1990/0227		nexterror(); }
1992/0825
1990/0227		n = arg[2];
1992/0825		dir = c->qid.path&CHDIR; if(dir) {
1990/0227		n -= n%DIRLEN; if(c->offset%DIRLEN || n==0)
1992/0114		error(Etoosmall);
1990/0227		}
1992/0825		if(dir && c->mnt)
1990/0227		n = unionread(c, (void*)arg[1], n); else
1991/0411		n = (*devtab[c->type].read)(c, (void*)arg[1], n, c->offset);
1992/0825		lock(c);
1991/1101		c->offset += n;
1992/0825		unlock(c); poperror(); close(c);
1990/0227		return n; } long
1994/0402		syswrite9p(ulong *arg) { Chan *c; long n; validaddr(arg[1], arg[2], 0); c = fdtochan(arg[0], OWRITE, 1, 1); if(waserror()) { close(c); nexterror(); } if(c->qid.path & CHDIR) error(Eisdir); if(devchar[c->type] != L'M') n = (*devtab[c->type].write)(c, (void*)arg[1], arg[2], c->offset); else n = mntwrite9p(c, (void*)arg[1], arg[2], c->offset); lock(c); c->offset += n; unlock(c); poperror(); close(c); return n; } long
1990/0227		syswrite(ulong *arg) { Chan *c; long n; validaddr(arg[1], arg[2], 0);
1992/0825		c = fdtochan(arg[0], OWRITE, 1, 1); if(waserror()) { close(c);
1990/0227		nexterror(); }
1992/0825
1990/11211		if(c->qid.path & CHDIR) error(Eisdir);
1992/0825
1991/0411		n = (*devtab[c->type].write)(c, (void*)arg[1], arg[2], c->offset);
1992/0825		lock(c);
1991/1101		c->offset += n;
1992/0825		unlock(c); poperror(); close(c);
1990/0227		return n; } long sysseek(ulong *arg) { Chan *c; char buf[DIRLEN]; Dir dir; long off;
1992/0825		c = fdtochan(arg[0], -1, 1, 0);
1990/11211		if(c->qid.path & CHDIR) error(Eisdir);
1992/0825
1991/0319		if(devchar[c->type] == '|') error(Eisstream);
1992/0825
1991/1101		off = 0;
1990/0227		switch(arg[2]){ case 0:
1991/1101		off = c->offset = arg[1];
1990/0227		break; case 1:
1992/0825		lock(c); /* lock for read/write update */
1990/0227		c->offset += (long)arg[1];
1991/1101		off = c->offset;
1992/0825		unlock(c);
1990/0227		break; case 2: (*devtab[c->type].stat)(c, buf); convM2D(buf, &dir); c->offset = dir.length + (long)arg[1];
1991/1101		off = c->offset;
1990/0227		break; } return off; } long sysfstat(ulong *arg) { Chan *c; validaddr(arg[1], DIRLEN, 1); evenaddr(arg[1]);
1992/0825		c = fdtochan(arg[0], -1, 0, 1); if(waserror()) { close(c); nexterror(); }
1990/0227		(*devtab[c->type].stat)(c, (char*)arg[1]);
1992/0825		poperror(); close(c);
1990/0227		return 0; } long sysstat(ulong *arg) { Chan *c; validaddr(arg[1], DIRLEN, 1); evenaddr(arg[1]); validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){ close(c); nexterror(); } (*devtab[c->type].stat)(c, (char*)arg[1]); poperror(); close(c); return 0; } long syschdir(ulong *arg) { Chan *c; validaddr(arg[0], 1, 0);
1993/0501
1990/0227		c = namec((char*)arg[0], Atodir, 0, 0);
1993/0501		close(up->dot); up->dot = c;
1990/0227		return 0; } long bindmount(ulong *arg, int ismount) { ulong flag;
1993/0501		int fd, ret; Chan *c0, *c1, *bc;
1990/0227		struct{ Chan *chan; char *spec;
1993/1014		int flags;
1990/0227		}bogus; flag = arg[2];
1992/0607		fd = arg[0];
1990/0227		if(flag>MMASK || (flag&MORDER)==(MBEFORE|MAFTER))
1990/11211		error(Ebadarg);
1993/0501
1993/1014		bogus.flags = flag & (MRECOV|MCACHE);
1993/0501
1990/0227		if(ismount){
1993/0501		bc = fdtochan(fd, ORDWR, 0, 1);
1992/0825		if(waserror()) { close(bc); nexterror(); } bogus.chan = bc;
1990/11211		validaddr(arg[3], 1, 0);
1991/0615		if(vmemchr((char*)arg[3], '\0', NAMELEN) == 0) error(Ebadarg);
1992/0825
1990/0227		bogus.spec = (char*)arg[3];
1992/0825
1990/0227		ret = devno('M', 0); c0 = (*devtab[ret].attach)((char*)&bogus);
1992/0825		poperror(); close(bc); } else {
1993/0501		bogus.spec = 0;
1990/0227		validaddr(arg[0], 1, 0); c0 = namec((char*)arg[0], Aaccess, 0, 0); }
1993/0501
1990/0227		if(waserror()){ close(c0); nexterror(); }
1993/0501
1990/0227		validaddr(arg[1], 1, 0); c1 = namec((char*)arg[1], Amount, 0, 0); if(waserror()){ close(c1); nexterror(); }
1993/0501		ret = mount(c0, c1, flag, bogus.spec);
1991/0614		poperror();
1990/0227		close(c1);
1991/0614		poperror(); close(c0);
1991/0705		if(ismount)
1992/0607		fdclose(fd, 0);
1990/0227		return ret; } long sysbind(ulong *arg) { return bindmount(arg, 0); } long sysmount(ulong *arg) { return bindmount(arg, 1); } long
1991/1011		sysunmount(ulong *arg) { Chan *cmount, *cmounted; cmounted = 0; validaddr(arg[1], 1, 0); cmount = namec((char *)arg[1], Amount, 0, 0); if(arg[0]) { if(waserror()) { close(cmount); nexterror(); } validaddr(arg[0], 1, 0);
1993/1111		cmounted = namec((char*)arg[0], Aopen, OREAD, 0);
1991/1011		poperror(); } if(waserror()) { close(cmount); if(cmounted) close(cmounted); nexterror(); } unmount(cmount, cmounted); close(cmount); if(cmounted) close(cmounted); poperror(); return 0; } long
1990/0227		syscreate(ulong *arg) { int fd;
1991/0705		Chan *c = 0;
1990/0227		openmode(arg[1]); /* error check only */
1991/0705		if(waserror()) { if(c) close(c); nexterror(); }
1990/0227		validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Acreate, arg[1], arg[2]);
1991/0705		fd = newfd(c); poperror();
1990/0227		return fd; } long sysremove(ulong *arg) { Chan *c; validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){
1990/0703		c->type = 0; /* see below */
1990/0227		close(c); nexterror(); } (*devtab[c->type].remove)(c); /* * Remove clunks the fid, but we need to recover the Chan * so fake it up. rootclose() is known to be a nop. */ c->type = 0;
1991/0614		poperror();
1990/0227		close(c); return 0; } long syswstat(ulong *arg) { Chan *c; validaddr(arg[1], DIRLEN, 0);
1991/1107		nameok((char*)arg[1]);
1990/0227		validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){ close(c); nexterror(); } (*devtab[c->type].wstat)(c, (char*)arg[1]); poperror(); close(c); return 0; } long sysfwstat(ulong *arg) { Chan *c; validaddr(arg[1], DIRLEN, 0);
1991/1107		nameok((char*)arg[1]);
1992/0825		c = fdtochan(arg[0], -1, 1, 1); if(waserror()) { close(c); nexterror(); }
1990/0227		(*devtab[c->type].wstat)(c, (char*)arg[1]);
1992/0825		poperror(); close(c);
1990/0227		return 0; }