[PATCH 5.4 101/215] loop: Factor out setting loop device size

Greg Kroah-Hartman
2024-04-11T10:19:02Z

From: Martijn Coenen <maco@android.com>

[ Upstream commit 5795b6f5607f7e4db62ddea144727780cb351a9b ]

This code is used repeatedly.

Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/loop.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)

--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -226,20 +226,35 @@ static void __loop_update_dio(struct loo
blk_mq_unfreeze_queue(lo->lo_queue);
}

+/**
+ * loop_set_size() - sets device size and notifies userspace
+ * @lo: struct loop_device to set the size for
+ * @size: new size of the loop device
+ *
+ * Callers must validate that the size passed into this function fits into
+ * a sector_t, eg using loop_validate_size()
+ */
+static void loop_set_size(struct loop_device *lo, loff_t size)
+{
+ struct block_device *bdev = lo->lo_device;
+
+ set_capacity(lo->lo_disk, size);
+ bd_set_size(bdev, size << SECTOR_SHIFT);
+ /* let user-space know about the new size */
+ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+}
+
static void
figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
{
loff_t size = get_size(offset, sizelimit, lo->lo_backing_file);
- struct block_device *bdev = lo->lo_device;

if (lo->lo_offset != offset)
lo->lo_offset = offset;
if (lo->lo_sizelimit != sizelimit)
lo->lo_sizelimit = sizelimit;
- set_capacity(lo->lo_disk, size);
- bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9);
- /* let user-space know about the new size */
- kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+
+ loop_set_size(lo, size);
}

static inline int
@@ -1033,11 +1048,8 @@ static int loop_set_fd(struct loop_devic

loop_update_rotational(lo);
loop_update_dio(lo);
- set_capacity(lo->lo_disk, size);
- bd_set_size(bdev, size << 9);
loop_sysfs_init(lo);
- /* let user-space know about the new size */
- kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+ loop_set_size(lo, size);

set_blocksize(bdev, S_ISBLK(inode->i_mode) ?
block_size(inode->i_bdev) : PAGE_SIZE);