ref: a291bbdeddfd41a2f0907ecbd7b819f0eedffdaf
dir: /sys/src/cmd/dossrv/devio.c/
#include <u.h> #include <libc.h> #include "iotrack.h" #include "dat.h" #include "fns.h" int readonly; static int deverror(char *name, Xfs *xf, long addr, long n, long nret) { errno = Eio; if(nret < 0){ chat("%s errstr=\"%r\"...", name); close(xf->dev); xf->dev = -1; return -1; } fprint(2, "dev %d sector %ld, %s: %ld, should be %ld\n", xf->dev, addr, name, nret, n); return -1; } int devread(Xfs *xf, long addr, void *buf, long n) { long nread; if(xf->dev < 0) return -1; nread = pread(xf->dev, buf, n, xf->offset+(vlong)addr*Sectorsize); if (nread == n) return 0; return deverror("read", xf, addr, n, nread); } int devwrite(Xfs *xf, long addr, void *buf, long n) { long nwrite; if(xf->omode==OREAD) return -1; if(xf->dev < 0) return -1; nwrite = pwrite(xf->dev, buf, n, xf->offset+(vlong)addr*Sectorsize); if (nwrite == n) return 0; return deverror("write", xf, addr, n, nwrite); } int devcheck(Xfs *xf) { char buf[Sectorsize]; if(xf->dev < 0) return -1; if(pread(xf->dev, buf, Sectorsize, 0) != Sectorsize){ close(xf->dev); xf->dev = -1; return -1; } return 0; }