lustre/kernel_patches/patches/dev_read_only-2.6-lnxi.patch

   1 Index: linux-2.6.5-lnxi/drivers/block/ll_rw_blk.c
   2 ===================================================================
   3 --- linux-2.6.5-lnxi.orig/drivers/block/ll_rw_blk.c
   4 +++ linux-2.6.5-lnxi/drivers/block/ll_rw_blk.c
   5 @@ -2718,7 +2718,7 @@ static inline void blk_partition_remap(s
   6         }
   7  }
   8
   9 -int dev_check_rdonly(dev_t dev);
  10 +int dev_check_rdonly(struct block_device *bdev);
  11
  12  /**
  13   * generic_make_request: hand a buffer to its device driver for I/O
  14 @@ -2810,7 +2810,7 @@ end_io:
  15
  16                 /* this is cfs's dev_rdonly check */
  17                 if (bio->bi_rw == WRITE &&
  18 -                               dev_check_rdonly(bio->bi_bdev->bd_dev)) {
  19 +                               dev_check_rdonly(bio->bi_bdev)) {
  20                         bio_endio(bio, bio->bi_size, 0);
  21                         break;
  22                 }
  23 @@ -3395,53 +3395,86 @@ void swap_io_context(struct io_context *
  24         *ioc2 = temp;
  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 +struct deventry {
  37 +       dev_t dev;
  38 +       struct deventry *next;
  39 +};
  40 +
  41 +static struct deventry *devlist = NULL;
  42 +static spinlock_t devlock = SPIN_LOCK_UNLOCKED;
  43 +
  44 +int dev_check_rdonly(struct block_device *bdev)
  45  {
  46 -       if (no_write >= MAX_RDONLY_DEVS) {
  47 -               printk(KERN_ALERT "%s:%d illegal arg %d (max %d)\n",
  48 -                               __FILE__, __LINE__, no_write, MAX_RDONLY_DEVS);
  49 -               return;
  50 +       struct deventry *cur;
  51 +       if (!bdev) return 0;
  52 +       spin_lock(&devlock);
  53 +       cur = devlist;
  54 +       while(cur) {
  55 +               if (bdev->bd_dev == cur->dev) {
  56 +                       spin_unlock(&devlock);
  57 +                       return 1;
  58         }
  59 -
  60 -       if (bdev) {
  61 -               printk(KERN_WARNING "Turning device %s read-only at %d\n",
  62 -                               bdev->bd_disk ? bdev->bd_disk->disk_name : "?",
  63 -                               no_write);
  64 -               rdonly_devs[no_write] = bdev->bd_dev;
  65 +               cur = cur->next;
  66         }
  67 +       spin_unlock(&devlock);
  68 +       return 0;
  69  }
  70
  71 -void dev_clear_rdonly(int no_write)
  72 +void dev_set_rdonly(struct block_device *bdev)
  73  {
  74 -       if (no_write >= MAX_RDONLY_DEVS) {
  75 -               printk(KERN_ALERT "%s:%d illegal arg %d (max %d)\n",
  76 -                               __FILE__, __LINE__, no_write, MAX_RDONLY_DEVS);
  77 -               return;
  78 -       }
  79 +       struct deventry *newdev, *cur;
  80
  81 -       if (rdonly_devs[no_write] == 0)
  82 +       if (!bdev)
  83 +               return;
  84 +       newdev = kmalloc(sizeof(struct deventry), GFP_KERNEL);
  85 +       if (!newdev)
  86                 return;
  87
  88 -       printk(KERN_WARNING "Clearing read-only at %d\n", no_write);
  89 -       rdonly_devs[no_write] = 0;
  90 -}
  91 -
  92 -int dev_check_rdonly(dev_t dev)
  93 -{
  94 -       int i;
  95 -
  96 -       for (i = 0; i < MAX_RDONLY_DEVS; i++)
  97 -               if (rdonly_devs[i] == dev)
  98 -                       return 1;
  99 -       return 0;
 100 +       spin_lock(&devlock);
 101 +       cur = devlist;
 102 +       while(cur) {
 103 +               if (bdev->bd_dev == cur->dev) {
 104 +                       spin_unlock(&devlock);
 105 +                       kfree(newdev);
 106 +                       return;
 107 +               }
 108 +               cur = cur->next;
 109 +       }
 110 +       newdev->dev = bdev->bd_dev;
 111 +       newdev->next = devlist;
 112 +       devlist = newdev;
 113 +       spin_unlock(&devlock);
 114 +       printk(KERN_WARNING "Turning device %s (%#x) read-only\n",
 115 +              bdev->bd_disk ? bdev->bd_disk->disk_name : "", bdev->bd_dev);
 116 +}
 117 +
 118 +void dev_clear_rdonly(struct block_device *bdev)
 119 +{
 120 +       struct deventry *cur, *last = NULL;
 121 +       if (!bdev) return;
 122 +       spin_lock(&devlock);
 123 +       cur = devlist;
 124 +       while(cur) {
 125 +               if (bdev->bd_dev == cur->dev) {
 126 +                       if (last)
 127 +                               last->next = cur->next;
 128 +                       else
 129 +                               devlist = cur->next;
 130 +                       spin_unlock(&devlock);
 131 +                       kfree(cur);
 132 +                       printk(KERN_WARNING "Removing read-only on %s (%#x)\n",
 133 +                              bdev->bd_disk ? bdev->bd_disk->disk_name :
 134 +                                              "unknown block", bdev->bd_dev);
 135 +                       return;
 136 +               }
 137 +               last = cur;
 138 +               cur = cur->next;
 139 +       }
 140 +       spin_unlock(&devlock);
 141  }
 142
 143  EXPORT_SYMBOL(dev_set_rdonly);
 144 Index: linux-2.6.5-lnxi/fs/block_dev.c
 145 ===================================================================
 146 --- linux-2.6.5-lnxi.orig/fs/block_dev.c
 147 +++ linux-2.6.5-lnxi/fs/block_dev.c
 148 @@ -767,6 +767,7 @@ int blkdev_put(struct block_device *bdev
 149                         blkdev_put(bdev->bd_contains);
 150                 }
 151                 bdev->bd_contains = NULL;
 152 +               dev_clear_rdonly(bdev);
 153         }
 154         unlock_kernel();
 155         up(&bdev->bd_sem);
 156 Index: linux-2.6.5-lnxi/include/linux/fs.h
 157 ===================================================================
 158 --- linux-2.6.5-lnxi.orig/include/linux/fs.h
 159 +++ linux-2.6.5-lnxi/include/linux/fs.h
 160 @@ -1424,6 +1424,10 @@ extern void file_kill(struct file *f);
 161  struct bio;
 162  extern int submit_bio(int, struct bio *);
 163  extern int bdev_read_only(struct block_device *);
 164 +#define HAVE_CLEAR_RDONLY_ON_PUT
 165 +void dev_set_rdonly(struct block_device *bdev);
 166 +int dev_check_rdonly(struct block_device *bdev);
 167 +void dev_clear_rdonly(struct block_device *bdev);
 168  extern int set_blocksize(struct block_device *, int);
 169  extern int sb_set_blocksize(struct super_block *, int);
 170  extern int sb_min_blocksize(struct super_block *, int);