lustre/kernel_patches/patches/dev_read_only_2.4.21-chaos.patch

   1 --- linux-2.4.24.orig/drivers/block/ll_rw_blk.c 2005-04-07 17:30:58.978035892 -0700
   2 +++ linux-2.4.24/drivers/block/ll_rw_blk.c      2005-04-07 17:22:04.354867801 -0700
   3 @@ -691,6 +691,85 @@ void set_device_ro(kdev_t dev,int flag)
   4         else ro_bits[major][minor >> 5] &= ~(1 << (minor & 31));
   5  }
   6
   7 +
   8 +/*
   9 + * Debug code for turning block devices read-only *silently* (will
  10 + * discard writes silently).  This is only for filesystem crash/recovery
  11 + * testing.
  12 + */
  13 +struct deventry {
  14 +       kdev_t dev;
  15 +       struct deventry *next;
  16 +};
  17 +
  18 +static struct deventry *devlist = NULL;
  19 +static spinlock_t devlock = SPIN_LOCK_UNLOCKED;
  20 +
  21 +int dev_check_rdonly(kdev_t dev) {
  22 +       struct deventry *cur;
  23 +       spin_lock(&devlock);
  24 +       cur = devlist;
  25 +       while(cur) {
  26 +               if (dev == cur->dev) {
  27 +                       spin_unlock(&devlock);
  28 +                       return 1;
  29 +               }
  30 +               cur = cur->next;
  31 +       }
  32 +       spin_unlock(&devlock);
  33 +       return 0;
  34 +}
  35 +
  36 +void dev_set_rdonly(kdev_t dev)
  37 +{
  38 +       struct deventry *newdev, *cur;
  39 +       newdev = kmalloc(sizeof(struct deventry), GFP_KERNEL);
  40 +       if (!newdev) return;
  41 +
  42 +       spin_lock(&devlock);
  43 +       cur = devlist;
  44 +       while(cur) {
  45 +               if (dev == cur->dev) {
  46 +                       spin_unlock(&devlock);
  47 +                       kfree(newdev);
  48 +                       return;
  49 +               }
  50 +               cur = cur->next;
  51 +       }
  52 +       newdev->dev = dev;
  53 +       newdev->next = devlist;
  54 +       devlist = newdev;
  55 +       spin_unlock(&devlock);
  56 +       printk(KERN_WARNING "Turning device %s read-only\n", bdevname(dev));
  57 +}
  58 +
  59 +void dev_clear_rdonly(kdev_t dev) {
  60 +       struct deventry *cur, *last = NULL;
  61 +       spin_lock(&devlock);
  62 +       cur = devlist;
  63 +       while(cur) {
  64 +               if (dev == cur->dev) {
  65 +                       if (last)
  66 +                               last->next = cur->next;
  67 +                       else
  68 +                               devlist = cur->next;
  69 +                       spin_unlock(&devlock);
  70 +                       kfree(cur);
  71 +                       printk(KERN_WARNING "Removing read-only on %s\n",
  72 +                              bdevname(dev));
  73 +                       return;
  74 +               }
  75 +               last = cur;
  76 +               cur = cur->next;
  77 +       }
  78 +       spin_unlock(&devlock);
  79 +}
  80 +
  81 +EXPORT_SYMBOL(dev_set_rdonly);
  82 +EXPORT_SYMBOL(dev_check_rdonly);
  83 +EXPORT_SYMBOL(dev_clear_rdonly);
  84 +
  85 +
  86  inline void drive_stat_acct (kdev_t dev, int rw,
  87                                 unsigned long nr_sectors, int new_io)
  88  {
  89 @@ -1256,6 +1336,10 @@ void generic_make_request (int rw, struc
  90                         break;
  91                 }
  92
  93 +               if ((rw & WRITE)&&(dev_check_rdonly(bh->b_rdev))) {
  94 +                       bh->b_end_io(bh, 0);
  95 +                       break;
  96 +               }
  97         } while (q->make_request_fn(q, rw, bh));
  98  }
  99
 100 --- linux-2.4.24.orig/include/linux/fs.h        2003-11-28 10:26:21.000000000 -0800
 101 +++ linux-2.4.24/include/linux/fs.h     2005-04-07 17:03:36.810595409 -0700
 102 @@ -1418,6 +1418,10 @@ extern struct buffer_head * getblk(kdev_
 103  extern void ll_rw_block(int, int, struct buffer_head * bh[]);
 104  extern void submit_bh(int, struct buffer_head *);
 105  extern int is_read_only(kdev_t);
 106 +#define HAVE_CLEAR_RDONLY_ON_PUT
 107 +void dev_set_rdonly(kdev_t dev);
 108 +int dev_check_rdonly(kdev_t dev);
 109 +void dev_clear_rdonly(kdev_t dev);
 110  extern void __brelse(struct buffer_head *);
 111  static inline void brelse(struct buffer_head *buf)
 112  {
 113 --- linux-2.4.24.orig/fs/block_dev.c    2003-06-13 07:51:37.000000000 -0700
 114 +++ linux-2.4.24/fs/block_dev.c 2005-04-07 14:01:49.000000000 -0700
 115 @@ -645,6 +645,7 @@ int blkdev_put(struct block_device *bdev
 116                 bdev->bd_op = NULL;
 117         unlock_kernel();
 118         up(&bdev->bd_sem);
 119 +       dev_clear_rdonly(to_kdev_t(bdev->bd_dev));
 120         bdput(bdev);
 121         return ret;
 122  }