block: move bdev_disk_changed

Move bdev_disk_changed to block/partitions/core.c, together with the
rest of the partition scanning code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210624123240.441814-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 54 insertions, 1 deletions

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 186d4fbd9f09..b79785f7027c 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -596,7 +596,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
 	return true;
 }
 
-int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
+static int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
 {
 	struct parsed_partitions *state;
 	int ret = -EAGAIN, p;
@@ -657,6 +657,59 @@ out_free_state:
 	return ret;
 }
 
+int bdev_disk_changed(struct block_device *bdev, bool invalidate)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	int ret = 0;
+
+	lockdep_assert_held(&disk->open_mutex);
+
+	if (!(disk->flags & GENHD_FL_UP))
+		return -ENXIO;
+
+rescan:
+	if (disk->open_partitions)
+		return -EBUSY;
+	sync_blockdev(bdev);
+	invalidate_bdev(bdev);
+	blk_drop_partitions(disk);
+
+	clear_bit(GD_NEED_PART_SCAN, &disk->state);
+
+	/*
+	 * Historically we only set the capacity to zero for devices that
+	 * support partitions (independ of actually having partitions created).
+	 * Doing that is rather inconsistent, but changing it broke legacy
+	 * udisks polling for legacy ide-cdrom devices.  Use the crude check
+	 * below to get the sane behavior for most device while not breaking
+	 * userspace for this particular setup.
+	 */
+	if (invalidate) {
+		if (disk_part_scan_enabled(disk) ||
+		    !(disk->flags & GENHD_FL_REMOVABLE))
+			set_capacity(disk, 0);
+	}
+
+	if (get_capacity(disk)) {
+		ret = blk_add_partitions(disk, bdev);
+		if (ret == -EAGAIN)
+			goto rescan;
+	} else if (invalidate) {
+		/*
+		 * Tell userspace that the media / partition table may have
+		 * changed.
+		 */
+		kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+	}
+
+	return ret;
+}
+/*
+ * Only exported for loop and dasd for historic reasons.  Don't use in new
+ * code!
+ */
+EXPORT_SYMBOL_GPL(bdev_disk_changed);
+
 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
 {
 	struct address_space *mapping = state->bdev->bd_inode->i_mapping;