Commit 355341e4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: don't require ->write_iter for writable files in loop_configure 



Block devices can be opened read-write even if they can't be written to
for historic reasons.  Remove the check requiring file->f_op->write_iter
when the block devices was opened in loop_configure. The call to
loop_check_backing_file just below ensures the ->write_iter is present
for backing files opened for writing, which is the only check that is
actually needed.

Fixes: f5c84eff ("loop: Add sanity check for read/write_iter")
Reported-by: default avatarChristian Hesse <mail@eworm.de>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250520135420.1177312-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dd24f87f

drivers/block/loop.c

+0 −3
Original line number Diff line number Diff line
@@ -979,9 +979,6 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
	if (!file)

		return -EBADF;



	if ((mode & BLK_OPEN_WRITE) && !file->f_op->write_iter)

		return -EINVAL;



	error = loop_check_backing_file(file);

	if (error)

		return error;