lustre/kernel_patches/patches/dev_read_only_2.6.0.patch

   1  drivers/block/ll_rw_blk.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++
   2  include/linux/blkdev.h    |    1
   3  2 files changed, 50 insertions(+)
   4
   5 --- linux-2.6.0-test6/drivers/block/ll_rw_blk.c~dev_read_only_2.6.0     2003-10-14 19:56:55.000000000 +0400
   6 +++ linux-2.6.0-test6-alexey/drivers/block/ll_rw_blk.c  2003-10-22 01:35:56.000000000 +0400
   7 @@ -2213,6 +2213,9 @@ end_io:
   8
   9                 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))
  10                         goto end_io;
  11 +               if (test_bit(QUEUE_FLAG_RDONLY, &q->queue_flags)
  12 +                               && bio->bi_rw == WRITE)
  13 +                       goto end_io;
  14
  15                 /*
  16                  * If this device has partitions, remap block n
  17 @@ -2867,6 +2870,52 @@ void blk_unregister_queue(struct gendisk
  18         }
  19  }
  20
  21 +#define MAX_RDONLY_DEVS                16
  22 +
  23 +static struct block_device *rdonly_devs[MAX_RDONLY_DEVS] = {0, };
  24 +
  25 +/*
  26 + * Debug code for turning block devices "read-only" (will discard writes
  27 + * silently).  This is for filesystem crash/recovery testing.
  28 + */
  29 +void dev_set_rdonly(struct block_device *bdev, int no_write)
  30 +{
  31 +       if (bdev) {
  32 +               request_queue_t *q;
  33 +
  34 +               q = bdev_get_queue(bdev);
  35 +               if (!q) {
  36 +                       printk(KERN_ERR
  37 +                               "dev_set_rdonly() for non-existing device\n");
  38 +                       return;
  39 +               }
  40 +               printk(KERN_WARNING "Turning device %s read-only\n",
  41 +                               bdev->bd_disk ? bdev->bd_disk->disk_name : "?");
  42 +               set_bit(QUEUE_FLAG_RDONLY, &q->queue_flags);
  43 +               rdonly_devs[no_write] = bdev;
  44 +       }
  45 +}
  46 +
  47 +void dev_clear_rdonly(int no_write)
  48 +{
  49 +       request_queue_t *q;
  50 +
  51 +       if (rdonly_devs[no_write] == NULL)
  52 +               return;
  53 +
  54 +       q = bdev_get_queue(rdonly_devs[no_write]);
  55 +       if (!q) {
  56 +               printk(KERN_ERR
  57 +                       "dev_clear_rdonly: no queue for device at slot %d\n",
  58 +                       no_write);
  59 +               return;
  60 +       }
  61 +       clear_bit(QUEUE_FLAG_RDONLY, &q->queue_flags);
  62 +       rdonly_devs[no_write] = NULL;
  63 +}
  64 +
  65 +EXPORT_SYMBOL(dev_set_rdonly);
  66 +EXPORT_SYMBOL(dev_clear_rdonly);
  67
  68  EXPORT_SYMBOL(process_that_request_first);
  69  EXPORT_SYMBOL(end_that_request_first);
  70 --- linux-2.6.0-test6/include/linux/blkdev.h~dev_read_only_2.6.0        2003-10-14 19:57:05.000000000 +0400
  71 +++ linux-2.6.0-test6-alexey/include/linux/blkdev.h     2003-10-21 23:31:18.000000000 +0400
  72 @@ -367,6 +367,7 @@ struct request_queue
  73  #define        QUEUE_FLAG_READFULL     3       /* write queue has been filled */
  74  #define QUEUE_FLAG_WRITEFULL   4       /* read queue has been filled */
  75  #define QUEUE_FLAG_DEAD                5       /* queue being torn down */
  76 +#define QUEUE_FLAG_RDONLY      6       /* queue accepts reads only */
  77
  78  #define blk_queue_plugged(q)   !list_empty(&(q)->plug_list)
  79  #define blk_queue_tagged(q)    test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
  80
  81 _