1997/0408/ip/kio.c (diff list | history)

ip/kio.c on 1997/0327
1997/0327		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "kernel.h" #define validaddr(a, b, c) long kclose(int fd) { if(waserror()) return -1; /* * Take no reference on the chan because we don't really need the * data structure, and are calling fdtochan only for error checks. * fdclose takes care of processes racing through here. */ fdtochan(fd, -1, 0, 0); fdclose(fd, 0); poperror(); return 0; } long kopen(char *path, int mode) { int fd; Chan *c = 0; if(waserror()) { if(c) cclose(c); return -1; } openmode(mode); validaddr((ulong)path, 1, 0); c = namec(path, Aopen, mode, 0); fd = newfd(c); poperror(); return fd; } long kread(int fd, void *va, long n) { int dir; Chan *c; if(waserror()) return -1; validaddr((ulong)va, n, 1); c = fdtochan(fd, OREAD, 1, 1); if(waserror()) { cclose(c); nexterror(); } 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, va, n);
1997/0408		else if(devtab[c->type]->dc != L'M')
1997/0327		n = devtab[c->type]->read(c, va, n, c->offset); else n = mntread9p(c, va, n, c->offset); lock(c); c->offset += n; unlock(c); poperror(); cclose(c); poperror(); return n; } long kseek(int fd, int offset, int whence) { Chan *c; char buf[DIRLEN]; Dir dir; long off; if(waserror()) return -1; c = fdtochan(fd, -1, 1, 1); if(waserror()) { cclose(c); nexterror(); } if(c->qid.path & CHDIR) error(Eisdir);
1997/0408		if(devtab[c->type]->dc == '|')
1997/0327		error(Eisstream); off = 0; switch(whence) { case 0: off = c->offset = offset; break; case 1: lock(c); /* lock for read/write update */ c->offset += offset; off = c->offset; unlock(c); break; case 2: devtab[c->type]->stat(c, buf); convM2D(buf, &dir); c->offset = dir.length + offset; off = c->offset; break; } poperror(); cclose(c); poperror(); return off; } long kwrite(int fd, void *va, long n) { Chan *c; if(waserror()) return -1; validaddr((ulong)va, n, 0); c = fdtochan(fd, OWRITE, 1, 1); if(waserror()) { cclose(c); nexterror(); } if(c->qid.path & CHDIR) error(Eisdir); n = devtab[c->type]->write(c, va, n, c->offset); lock(c); c->offset += n; unlock(c); poperror(); cclose(c); poperror(); return n; } /* Set kernel error string */ void kerrstr(char *err) { if(up != nil) strncpy(up->error, err, ERRLEN); } /* Get kernel error string */ void kgerrstr(char *err) { char *s; s = "<no-up>"; if(up != nil) s = up->error; strncpy(err, s, ERRLEN); } /* Set kernel error string, using formatted print */ void kwerrstr(char *fmt, ...) { va_list arg; char buf[256]; va_start(arg, fmt); doprint(buf, buf+sizeof(buf), fmt, arg); va_end(arg); strncpy(up->error, buf, ERRLEN); }