lustre/kernel_patches/patches/dev_read_only_2.4.20.patch

   1 Index: linux-2.4.20-8/drivers/block/blkpg.c
   2 ===================================================================
   3 --- linux-2.4.20-8.orig/drivers/block/blkpg.c   2002-08-03 08:39:43.000000000 +0800
   4 +++ linux-2.4.20-8/drivers/block/blkpg.c        2003-12-08 15:50:20.000000000 +0800
   5 @@ -296,3 +296,42 @@
   6  }
   7
   8  EXPORT_SYMBOL(blk_ioctl);
   9 +
  10 +
  11 +
  12 +#define NUM_DEV_NO_WRITE 16
  13 +static int dev_no_write[NUM_DEV_NO_WRITE];
  14 +
  15 +/*
  16 + * Debug code for turning block devices "read-only" (will discard writes
  17 + * silently).  This is for filesystem crash/recovery testing.
  18 + */
  19 +void dev_set_rdonly(kdev_t dev, int no_write)
  20 +{
  21 +       if (dev) {
  22 +               printk(KERN_WARNING "Turning device %s read-only\n",
  23 +                      bdevname(dev));
  24 +               dev_no_write[no_write] = 0xdead0000 + dev;
  25 +       }
  26 +}
  27 +
  28 +int dev_check_rdonly(kdev_t dev) {
  29 +       int i;
  30 +
  31 +       for (i = 0; i < NUM_DEV_NO_WRITE; i++) {
  32 +               if ((dev_no_write[i] & 0xffff0000) == 0xdead0000 &&
  33 +                   dev == (dev_no_write[i] & 0xffff))
  34 +                       return 1;
  35 +       }
  36 +       return 0;
  37 +}
  38 +
  39 +void dev_clear_rdonly(int no_write) {
  40 +       dev_no_write[no_write] = 0;
  41 +}
  42 +
  43 +EXPORT_SYMBOL(dev_set_rdonly);
  44 +EXPORT_SYMBOL(dev_check_rdonly);
  45 +EXPORT_SYMBOL(dev_clear_rdonly);
  46 +
  47 +
  48 Index: linux-2.4.20-8/drivers/block/ll_rw_blk.c
  49 ===================================================================
  50 --- linux-2.4.20-8.orig/drivers/block/ll_rw_blk.c       2003-12-08 15:47:50.000000000 +0800
  51 +++ linux-2.4.20-8/drivers/block/ll_rw_blk.c    2003-12-08 15:51:17.000000000 +0800
  52 @@ -1164,6 +1164,10 @@
  53                         buffer_IO_error(bh);
  54                         break;
  55                 }
  56 +               if ((dev_check_rdonly(bh->b_rdev))&&(rw & WRITE)) {
  57 +                        bh->b_end_io(bh, 0);
  58 +                        break;
  59 +                }
  60         } while (q->make_request_fn(q, rw, bh));
  61  }
  62