Re: [PATCH v4 02/10] loop: Factor out setting loop device size

[Christoph Hellwig]

On Wed, Apr 29, 2020 at 04:03:33PM +0200, Martijn Coenen wrote:
> This code is used repeatedly.
> 
> Signed-off-by: Martijn Coenen 
> ---
>  drivers/block/loop.c | 31 ++-
>  1 file changed, 22 insertions(+), 9 deletions(-)

Looks good:

Reviewed-by: Christoph Hellwig 

[PATCH v4 02/10] loop: Factor out setting loop device size

[Martijn Coenen]

This code is used repeatedly.

Signed-off-by: Martijn Coenen 
---
 drivers/block/loop.c | 31 ++-
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 396b8bd4d75c..6643e48ad71c 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -241,12 +241,29 @@ loop_validate_size(loff_t size)
return 0;
 }
 
+/**
+ * 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(_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+}
+
 static int
 figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
 {
int err;
loff_t size = get_size(offset, sizelimit, lo->lo_backing_file);
-   struct block_device *bdev = lo->lo_device;
 
err = loop_validate_size(size);
if (err)
@@ -256,10 +273,9 @@ figure_loop_size(struct loop_device *lo, loff_t offset, 
loff_t sizelimit)
lo->lo_offset = offset;
if (lo->lo_sizelimit != sizelimit)
lo->lo_sizelimit = sizelimit;
-   set_capacity(lo->lo_disk, x);
-   bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9);
-   /* let user-space know about the new size */
-   kobject_uevent(_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+
+   loop_set_size(lo, size);
+
return 0;
 }
 
@@ -1055,11 +1071,8 @@ static int loop_set_fd(struct loop_device *lo, fmode_t 
mode,
 
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(_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);
-- 
2.26.2.303.gf8c07b1a785-goog