block: merge invalidate_partitions into rescan_partitions

A lot of the logic in invalidate_partitions and rescan_partitions is
shared.  Merge the two functions to simplify things.  There is a small
behavior change in that we now send the kevent change notice also if we
were not invalidating but no partitions were found, which seems like
the right thing to do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/ioctl.c

@@ -171,7 +171,7 @@ int __blkdev_reread_part(struct block_device *bdev)
 
 	lockdep_assert_held(&bdev->bd_mutex);
 
-	return rescan_partitions(disk, bdev);
+	return rescan_partitions(disk, bdev, false);
 }
 EXPORT_SYMBOL(__blkdev_reread_part);
 

block/partition-generic.c

@@ -576,7 +576,8 @@ static int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
 	return ret;
 }
 
-int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
+int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
+		bool invalidate)
 {
 	int ret;
 
@@ -585,13 +586,22 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 	if (ret)
 		return ret;
 
-	if (disk->fops->revalidate_disk)
+	if (invalidate)
+		set_capacity(disk, 0);
+	else if (disk->fops->revalidate_disk)
 		disk->fops->revalidate_disk(disk);
-	check_disk_size_change(disk, bdev, true);
+
+	check_disk_size_change(disk, bdev, !invalidate);
 	bdev->bd_invalidated = 0;
 
-	if (!get_capacity(disk))
+	if (!get_capacity(disk)) {
+		/*
+		 * Tell userspace that the media / partition table may have
+		 * changed.
+		 */
+		kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 		return 0;
+	}
 
 	ret = blk_add_partitions(disk, bdev);
 	if (ret == -EAGAIN)
@@ -599,26 +609,6 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 	return ret;
 }
 
-int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
-{
-	int res;
-
-	if (!bdev->bd_invalidated)
-		return 0;
-
-	res = drop_partitions(disk, bdev);
-	if (res)
-		return res;
-
-	set_capacity(disk, 0);
-	check_disk_size_change(disk, bdev, false);
-	bdev->bd_invalidated = 0;
-	/* tell userspace that the media / partition table may have changed */
-	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
-
-	return 0;
-}
-
 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 {
 	struct address_space *mapping = bdev->bd_inode->i_mapping;

fs/block_dev.c

@@ -1511,10 +1511,7 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
 static void bdev_disk_changed(struct block_device *bdev, bool invalidate)
 {
 	if (disk_part_scan_enabled(bdev->bd_disk)) {
-		if (invalidate)
-			invalidate_partitions(bdev->bd_disk, bdev);
-		else
-			rescan_partitions(bdev->bd_disk, bdev);
+		rescan_partitions(bdev->bd_disk, bdev, invalidate);
 	} else {
 		check_disk_size_change(bdev->bd_disk, bdev, !invalidate);
 		bdev->bd_invalidated = 0;

include/linux/genhd.h

@@ -622,8 +622,8 @@ extern dev_t blk_lookup_devt(const char *name, int partno);
 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 
 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
-extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
-extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
+int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
+		bool invalidate);
 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 						     int partno, sector_t start,
 						     sector_t len, int flags,