lustre/kernel_patches/patches/dev_read_only-2.4.24.patch

   1 Index: linux-2.4.20-rh/drivers/block/blkpg.c
   2 ===================================================================
   3 --- linux-2.4.20-rh.orig/drivers/block/blkpg.c  2003-07-22 16:02:29.000000000 +0800
   4 +++ linux-2.4.20-rh/drivers/block/blkpg.c       2003-12-09 17:33:09.000000000 +0800
   5 @@ -297,3 +297,38 @@
   6  }
   7
   8  EXPORT_SYMBOL(blk_ioctl);
   9 +
  10 +#define NUM_DEV_NO_WRITE 16
  11 +static int dev_no_write[NUM_DEV_NO_WRITE];
  12 +
  13 +/*
  14 + * Debug code for turning block devices "read-only" (will discard writes
  15 + * silently).  This is for filesystem crash/recovery testing.
  16 + */
  17 +void dev_set_rdonly(kdev_t dev, int no_write)
  18 +{
  19 +       if (dev) {
  20 +               printk(KERN_WARNING "Turning device %s read-only\n",
  21 +                      bdevname(dev));
  22 +               dev_no_write[no_write] = 0xdead0000 + dev;
  23 +       }
  24 +}
  25 +
  26 +int dev_check_rdonly(kdev_t dev) {
  27 +       int i;
  28 +
  29 +       for (i = 0; i < NUM_DEV_NO_WRITE; i++) {
  30 +               if ((dev_no_write[i] & 0xffff0000) == 0xdead0000 &&
  31 +                   dev == (dev_no_write[i] & 0xffff))
  32 +                       return 1;
  33 +       }
  34 +       return 0;
  35 +}
  36 +
  37 +void dev_clear_rdonly(int no_write) {
  38 +       dev_no_write[no_write] = 0;
  39 +}
  40 +
  41 +EXPORT_SYMBOL(dev_set_rdonly);
  42 +EXPORT_SYMBOL(dev_check_rdonly);
  43 +EXPORT_SYMBOL(dev_clear_rdonly);
  44 Index: linux-2.4.20-rh/drivers/block/ll_rw_blk.c
  45 ===================================================================
  46 --- linux-2.4.20-rh.orig/drivers/block/ll_rw_blk.c      2003-07-22 16:02:34.000000000 +0800
  47 +++ linux-2.4.20-rh/drivers/block/ll_rw_blk.c   2003-12-09 17:39:38.000000000 +0800
  48 @@ -1183,6 +1183,10 @@
  49                         buffer_IO_error(bh);
  50                         break;
  51                 }
  52 +                if ((rw & WRITE)&&(dev_check_rdonly(bh->b_rdev))) {
  53 +                        bh->b_end_io(bh, 0);
  54 +                        break;
  55 +                }
  56         } while (q->make_request_fn(q, rw, bh));
  57  }
  58