lustre/kernel_patches/patches/dev_read_only-2.6.10-fc3.patch

   1  drivers/block/ll_rw_blk.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++
   2  include/linux/blkdev.h    |    1
   3  2 files changed, 50 insertions(+)
   4
   5 Index: linux-2.6.10/drivers/block/ll_rw_blk.c
   6 ===================================================================
   7 --- linux-2.6.10.orig/drivers/block/ll_rw_blk.c 2004-12-25 05:33:59.000000000 +0800
   8 +++ linux-2.6.10/drivers/block/ll_rw_blk.c      2005-04-05 15:42:58.075467024 +0800
   9 @@ -2679,6 +2679,13 @@
  10                 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))
  11                         goto end_io;
  12
  13 +                /* this is cfs's dev_rdonly check */
  14 +                if (bio->bi_rw == WRITE &&
  15 +                                dev_check_rdonly(bio->bi_bdev->bd_dev)) {
  16 +                        bio_endio(bio, bio->bi_size, 0);
  17 +                        break;
  18 +                }
  19 +
  20                 block_wait_queue_running(q);
  21
  22                 /*
  23 @@ -3287,6 +3294,58 @@
  24         return queue_var_show(max_hw_sectors_kb, (page));
  25  }
  26
  27 +#define MAX_RDONLY_DEVS                16
  28 +
  29 +static dev_t rdonly_devs[MAX_RDONLY_DEVS] = {0, };
  30 +
  31 +/*
  32 + * Debug code for turning block devices "read-only" (will discard writes
  33 + * silently).  This is for filesystem crash/recovery testing.
  34 + */
  35 +void dev_set_rdonly(struct block_device *bdev, int no_write)
  36 +{
  37 +       if (no_write >= MAX_RDONLY_DEVS) {
  38 +               printk(KERN_ALERT "%s:%d illegal arg %d (max %d)\n",
  39 +                               __FILE__, __LINE__, no_write, MAX_RDONLY_DEVS);
  40 +               return;
  41 +       }
  42 +
  43 +       if (bdev) {
  44 +               printk(KERN_WARNING "Turning device %s read-only at %d\n",
  45 +                               bdev->bd_disk ? bdev->bd_disk->disk_name : "?",
  46 +                               no_write);
  47 +               rdonly_devs[no_write] = bdev->bd_dev;
  48 +       }
  49 +}
  50 +
  51 +void dev_clear_rdonly(int no_write)
  52 +{
  53 +       if (no_write >= MAX_RDONLY_DEVS) {
  54 +               printk(KERN_ALERT "%s:%d illegal arg %d (max %d)\n",
  55 +                               __FILE__, __LINE__, no_write, MAX_RDONLY_DEVS);
  56 +               return;
  57 +       }
  58 +
  59 +       if (rdonly_devs[no_write] == 0)
  60 +               return;
  61 +
  62 +       printk(KERN_WARNING "Clearing read-only at %d\n", no_write);
  63 +       rdonly_devs[no_write] = 0;
  64 +}
  65 +
  66 +int dev_check_rdonly(dev_t dev)
  67 +{
  68 +       int i;
  69 +
  70 +       for (i = 0; i < MAX_RDONLY_DEVS; i++)
  71 +               if (rdonly_devs[i] == dev)
  72 +                       return 1;
  73 +       return 0;
  74 +}
  75 +
  76 +EXPORT_SYMBOL(dev_set_rdonly);
  77 +EXPORT_SYMBOL(dev_clear_rdonly);
  78 +EXPORT_SYMBOL(dev_check_rdonly);
  79
  80  static struct queue_sysfs_entry queue_requests_entry = {
  81         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },