Commit 79e5dc59 authored Aug 25, 2020 by Martijn Coenen Committed by Jens Axboe Aug 26, 2020

loop: Set correct device size when using LOOP_CONFIGURE



The device size calculation was done before processing the loop
configuration, which meant that the we set the size on the underlying
block device incorrectly in case lo_offset/lo_sizelimit were set in the
configuration. Delay computing the size until we've setup the device
parameters correctly.

Fixes: 3448914e("loop: Add LOOP_CONFIGURE ioctl")
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Tested-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent acb19e17

drivers/block/loop.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1114,8 +1114,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
		mapping = file->f_mapping;
		inode = mapping->host;

		size = get_loop_size(lo, file);

		if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) {
		error = -EINVAL;
		goto out_unlock;
		@@ -1165,6 +1163,8 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
		loop_update_rotational(lo);
		loop_update_dio(lo);
		loop_sysfs_init(lo);

		size = get_loop_size(lo, file);
		loop_set_size(lo, size);

		set_blocksize(bdev, S_ISBLK(inode->i_mode) ?

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