src/patches/suse-2.6.27.31/patches.suse/no-partition-scan

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: Implement 'no_partition_scan' commandline option
   3 Refences: FATE#303697
   4
   5 Under certain setups the partition table on the disk is not
   6 useable directly (eg for dmraid or multipathing). So we should
   7 be able to switch it off completely so as not to be flooded with
   8 pointless messages.
   9
  10 Signed-off-by: Hannes Reinecke <hare@suse.de>
  11
  12 ---
  13  block/genhd.c         |   38 ++++++++++++++++++++++++++++++++++++--
  14  fs/partitions/check.c |    2 ++
  15  include/linux/genhd.h |    1 +
  16  3 files changed, 39 insertions(+), 2 deletions(-)
  17
  18 --- a/block/genhd.c
  19 +++ b/block/genhd.c
  20 @@ -173,6 +173,18 @@ static int exact_lock(dev_t devt, void *
  21         return 0;
  22  }
  23
  24 +static int __read_mostly no_partition_scan;
  25 +
  26 +static int __init no_partition_scan_setup(char *str)
  27 +{
  28 +       no_partition_scan = 1;
  29 +       printk(KERN_INFO "genhd: omit partition scan.\n");
  30 +
  31 +       return 1;
  32 +}
  33 +
  34 +__setup("no_partition_scan", no_partition_scan_setup);
  35 +
  36  /**
  37   * add_disk - add partitioning information to kernel list
  38   * @disk: per-device partitioning information
  39 @@ -186,6 +198,8 @@ void add_disk(struct gendisk *disk)
  40         int retval;
  41
  42         disk->flags |= GENHD_FL_UP;
  43 +       if (no_partition_scan)
  44 +               disk->flags |= GENHD_FL_NO_PARTITION_SCAN;
  45         blk_register_region(MKDEV(disk->major, disk->first_minor),
  46                             disk->minors, NULL, exact_match, exact_lock, disk);
  47         register_disk(disk);
  48 @@ -429,7 +443,27 @@ static ssize_t disk_range_show(struct de
  49  {
  50         struct gendisk *disk = dev_to_disk(dev);
  51
  52 -       return sprintf(buf, "%d\n", disk->minors);
  53 +       return sprintf(buf, "%d\n",
  54 +                      (disk->flags & GENHD_FL_NO_PARTITION_SCAN ? 0 : disk->minors));
  55 +}
  56 +
  57 +static ssize_t disk_range_store(struct device *dev,
  58 +                               struct device_attribute *attr,
  59 +                               const char *buf, size_t count)
  60 +{
  61 +       struct gendisk *disk = dev_to_disk(dev);
  62 +       int i;
  63 +
  64 +       if (count > 0 && sscanf(buf, "%d", &i) > 0) {
  65 +               if (i == 0)
  66 +                       disk->flags |= GENHD_FL_NO_PARTITION_SCAN;
  67 +               else if (i <= disk->minors)
  68 +                       disk->flags &= ~GENHD_FL_NO_PARTITION_SCAN;
  69 +               else
  70 +                       count = -EINVAL;
  71 +       }
  72 +
  73 +       return count;
  74  }
  75
  76  static ssize_t disk_removable_show(struct device *dev,
  77 @@ -519,7 +553,7 @@ static ssize_t disk_fail_store(struct de
  78
  79  #endif
  80
  81 -static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
  82 +static DEVICE_ATTR(range, S_IRUGO|S_IWUSR, disk_range_show, disk_range_store);
  83  static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
  84  static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
  85  static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
  86 --- a/fs/partitions/check.c
  87 +++ b/fs/partitions/check.c
  88 @@ -486,6 +486,8 @@ int rescan_partitions(struct gendisk *di
  89                 disk->fops->revalidate_disk(disk);
  90         check_disk_size_change(disk, bdev);
  91         bdev->bd_invalidated = 0;
  92 +       if (disk->flags & GENHD_FL_NO_PARTITION_SCAN)
  93 +               return 0;
  94         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
  95                 return 0;
  96         if (IS_ERR(state))      /* I/O error reading the partition table */
  97 --- a/include/linux/genhd.h
  98 +++ b/include/linux/genhd.h
  99 @@ -109,6 +109,7 @@ struct hd_struct {
 100  #define GENHD_FL_UP                            16
 101  #define GENHD_FL_SUPPRESS_PARTITION_INFO       32
 102  #define GENHD_FL_FAIL                          64
 103 +#define GENHD_FL_NO_PARTITION_SCAN             128
 104
 105  struct gendisk {
 106         int major;                      /* major number of driver */