sys/src/cmd/dossrv/devio.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include "iotrack.h"
   4 #include "dat.h"
   5 #include "fns.h"
   6
   7 int readonly;
   8
   9 static int
  10 deverror(char *name, Xfs *xf, long addr, long n, long nret)
  11 {
  12         errno = Eio;
  13         if(nret < 0){
  14                 chat("%s errstr=\"%r\"...", name);
  15                 close(xf->dev);
  16                 xf->dev = -1;
  17                 return -1;
  18         }
  19         fprint(2, "dev %d sector %ld, %s: %ld, should be %ld\n", xf->dev, addr, name, nret, n);
  20         return -1;
  21 }
  22
  23 int
  24 devread(Xfs *xf, vlong addr, void *buf, long n)
  25 {
  26         long nread;
  27
  28         if(xf->dev < 0)
  29                 return -1;
  30         nread = pread(xf->dev, buf, n, xf->offset+addr*Sectorsize);
  31         if (nread == n)
  32                 return 0;
  33         return deverror("read", xf, addr, n, nread);
  34 }
  35
  36 int
  37 devwrite(Xfs *xf, vlong addr, void *buf, long n)
  38 {
  39         long nwrite;
  40
  41         if(xf->omode==OREAD)
  42                 return -1;
  43
  44         if(xf->dev < 0)
  45                 return -1;
  46         nwrite = pwrite(xf->dev, buf, n, xf->offset+addr*Sectorsize);
  47         if (nwrite == n)
  48                 return 0;
  49         return deverror("write", xf, addr, n, nwrite);
  50 }
  51
  52 int
  53 devcheck(Xfs *xf)
  54 {
  55         char buf[Sectorsize];
  56
  57         if(xf->dev < 0)
  58                 return -1;
  59         if(pread(xf->dev, buf, Sectorsize, 0) != Sectorsize){
  60                 close(xf->dev);
  61                 xf->dev = -1;
  62                 return -1;
  63         }
  64         return 0;
  65 }