src/patches/suse-2.6.27.31/patches.drivers/bdev-resize-adjust-block-device-size

   1 Subject: Adjust block device size after an online resize of a disk.
   2 From: Andrew Patterson <andrew.patterson@hp.com>
   3 Date: Thu Oct 9 08:56:12 2008 +0200:
   4 Git: c3279d1454cdfed02a557d789d8a6d08ab4cbe70
   5 References: FATE#302348,FATE#303786
   6
   7 The revalidate_disk routine now checks if a disk has been resized by
   8 comparing the gendisk capacity to the bdev inode size.  If they are
   9 different (usually because the disk has been resized underneath the kernel)
  10 the bdev inode size is adjusted to match the capacity.
  11
  12 Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
  13 Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
  14 Signed-off-by: Hannes Reinecke <hare@suse.de>
  15 ---
  16  fs/block_dev.c     |   37 +++++++++++++++++++++++++++++++++++++
  17  include/linux/fs.h |    2 ++
  18  2 files changed, 39 insertions(+)
  19
  20 --- a/fs/block_dev.c
  21 +++ b/fs/block_dev.c
  22 @@ -869,6 +869,34 @@ struct block_device *open_by_devnum(dev_
  23  EXPORT_SYMBOL(open_by_devnum);
  24
  25  /**
  26 + * check_disk_size_change - checks for disk size change and adjusts
  27 + *                          bdev size.
  28 + *
  29 + * @disk: struct gendisk to check
  30 + * @bdev: struct bdev to adjust.
  31 + *
  32 + * This routine checks to see if the bdev size does not match the disk size
  33 + * and adjusts it if it differs.
  34 + */
  35 +void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
  36 +{
  37 +       loff_t disk_size, bdev_size;
  38 +
  39 +       disk_size = (loff_t)get_capacity(disk) << 9;
  40 +       bdev_size = i_size_read(bdev->bd_inode);
  41 +       if (disk_size != bdev_size) {
  42 +               char name[BDEVNAME_SIZE];
  43 +
  44 +               disk_name(disk, 0, name);
  45 +               printk(KERN_INFO
  46 +                      "%s: detected capacity change from %lld to %lld\n",
  47 +                      name, bdev_size, disk_size);
  48 +               i_size_write(bdev->bd_inode, disk_size);
  49 +       }
  50 +}
  51 +EXPORT_SYMBOL(check_disk_size_change);
  52 +
  53 +/**
  54   * revalidate_disk - wrapper for lower-level driver's revalidate_disk
  55   *                   call-back
  56   *
  57 @@ -880,11 +908,20 @@ EXPORT_SYMBOL(open_by_devnum);
  58   */
  59  int revalidate_disk(struct gendisk *disk)
  60  {
  61 +       struct block_device *bdev;
  62         int ret = 0;
  63
  64         if (disk->fops->revalidate_disk)
  65                 ret = disk->fops->revalidate_disk(disk);
  66
  67 +       bdev = bdget_disk(disk, 0);
  68 +       if (!bdev)
  69 +               return ret;
  70 +
  71 +       mutex_lock(&bdev->bd_mutex);
  72 +       check_disk_size_change(disk, bdev);
  73 +       mutex_unlock(&bdev->bd_mutex);
  74 +       bdput(bdev);
  75         return ret;
  76  }
  77  EXPORT_SYMBOL(revalidate_disk);
  78 --- a/include/linux/fs.h
  79 +++ b/include/linux/fs.h
  80 @@ -1742,6 +1742,8 @@ extern int fs_may_remount_ro(struct supe
  81   */
  82  #define bio_data_dir(bio)      ((bio)->bi_rw & 1)
  83
  84 +extern void check_disk_size_change(struct gendisk *disk,
  85 +                                  struct block_device *bdev);
  86  extern int revalidate_disk(struct gendisk *);
  87  extern int check_disk_change(struct block_device *);
  88  extern int __invalidate_device(struct block_device *);