src/patches/grub-0.95-odirect.patch

   1 --- grub-0.95/grub/asmstub.c.odirect    2004-11-30 16:58:06.577019488 -0500
   2 +++ grub-0.95/grub/asmstub.c    2004-11-30 16:59:56.057375944 -0500
   3 @@ -53,6 +53,9 @@
   4  # ifndef BLKFLSBUF
   5  #  define BLKFLSBUF    _IO (0x12,97)   /* flush buffer cache */
   6  # endif /* ! BLKFLSBUF */
   7 +# ifndef O_DIRECT
   8 +#   define O_DIRECT 040000
   9 +# endif /* ! O_DIRECT */
  10  #endif /* __linux__ */
  11
  12  /* We want to prevent any circularararity in our stubs, as well as
  13 @@ -764,7 +767,7 @@
  14      {
  15        /* The unpartitioned device name: /dev/XdX */
  16        char *devname = device_map[drive];
  17 -      char buf[512];
  18 +      char * buf, * buf_unaligned;
  19
  20        if (! devname)
  21         return -1;
  22 @@ -775,13 +778,13 @@
  23
  24        /* Open read/write, or read-only if that failed. */
  25        if (! read_only)
  26 -       disks[drive].flags = open (devname, O_RDWR);
  27 +       disks[drive].flags = open (devname, O_RDWR | O_DIRECT);
  28
  29        if (disks[drive].flags == -1)
  30         {
  31           if (read_only || errno == EACCES || errno == EROFS || errno == EPERM)
  32             {
  33 -             disks[drive].flags = open (devname, O_RDONLY);
  34 +             disks[drive].flags = open (devname, O_RDONLY | O_DIRECT);
  35               if (disks[drive].flags == -1)
  36                 {
  37                   assign_device_name (drive, 0);
  38 @@ -795,6 +798,10 @@
  39             }
  40         }
  41
  42 +      buf_unaligned = malloc((512 * sizeof(char)) + 4095);
  43 +      buf = (char *) (((unsigned long)buf_unaligned + 4096 - 1) &
  44 +                      (~(4096-1)));
  45 +
  46        /* Attempt to read the first sector.  */
  47        if (read (disks[drive].flags, buf, 512) != 512)
  48         {
  49 @@ -806,6 +813,7 @@
  50
  51        if (disks[drive].flags != -1)
  52         get_drive_geometry (&disks[drive], device_map, drive);
  53 +      free(buf_unaligned);
  54      }
  55
  56    if (disks[drive].flags == -1)
  57 @@ -827,24 +835,34 @@
  58  nread (int fd, char *buf, size_t len)
  59  {
  60    int size = len;
  61 +  char * buf_unaligned, * buff, * obuff;
  62 +  int ret;
  63 +
  64 +  buf_unaligned = malloc((len * sizeof(char)) + 4095);
  65 +  obuff = buff = (char *) (((unsigned long)buf_unaligned + 4096 - 1) &
  66 +                           (~(4096-1)));
  67 +
  68
  69    while (len)
  70      {
  71 -      int ret = read (fd, buf, len);
  72 +      ret = read (fd, buff, len);
  73
  74        if (ret <= 0)
  75         {
  76           if (errno == EINTR)
  77             continue;
  78           else
  79 -           return ret;
  80 +            break;
  81         }
  82
  83        len -= ret;
  84 -      buf += ret;
  85 +      buff += ret;
  86      }
  87
  88 -  return size;
  89 +  if (!len) ret = size;
  90 +
  91 +  buf = memcpy(buf, obuff, size);
  92 +  return ret;
  93  }
  94
  95  /* Write LEN bytes from BUF to FD. Return less than or equal to zero if an
  96 @@ -853,10 +871,18 @@
  97  nwrite (int fd, char *buf, size_t len)
  98  {
  99    int size = len;
 100 +  char * buf_unaligned, * buff;
 101 +
 102 +  buf_unaligned = malloc((len * sizeof(char)) + 4095);
 103 +  buff = (char *) (((unsigned long)buf_unaligned + 4096 - 1) &
 104 +                   (~(4096-1)));
 105
 106    while (len)
 107      {
 108 -      int ret = write (fd, buf, len);
 109 +      int ret;
 110 +
 111 +      memcpy(buff, buf, len);
 112 +      ret = write (fd, buff, len);
 113
 114        if (ret <= 0)
 115         {