[PATCH 1/2] block: Set inode of block_device size to zero when delete gendisk.

[majianpeng]

When remove gendisk, set the size of inode of block_device to zero.
This is mainly let the vfs know disk removed.

Signed-off-by: Jianpeng Ma <majianp...@gmail.com>
---
 block/genhd.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index dadf42b..c3a54b4 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -634,6 +634,7 @@ void del_gendisk(struct gendisk *disk)
 {
        struct disk_part_iter piter;
        struct hd_struct *part;
+       struct block_device *bdev;
 
        disk_del_events(disk);
 
@@ -655,6 +656,19 @@ void del_gendisk(struct gendisk *disk)
        blk_unregister_queue(disk);
        blk_unregister_region(disk_devt(disk), disk->minors);
 
+       /*
+        * When used buffer-mode on raw blockdevice,the disk removed.
+        * But the vfs don't know.So tell the vfs size of disk became zero,
+        * the buffer write  can return
+        */
+       bdev = bdget_disk(disk, 0);
+       if (bdev) {
+               mutex_lock(&bdev->bd_inode->i_mutex);
+               i_size_write(bdev->bd_inode, 0);
+               mutex_unlock(&bdev->bd_inode->i_mutex);
+               bdput(bdev);
+       }
+
        part_stat_set_all(&disk->part0, 0);
        disk->part0.stamp = 0;
 
-- 
1.8.4-rc0