Commit d2781648 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: factor out a loop_assign_backing_file helper 



Split the code for setting up a backing file into a helper in preparation
of adding more code to this path.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250131120120.1315125-2-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8985c429

drivers/block/loop.c

+10 −10
Original line number Diff line number Diff line
@@ -573,6 +573,14 @@ static int loop_validate_file(struct file *file, struct block_device *bdev) 
	return 0;

}



static void loop_assign_backing_file(struct loop_device *lo, struct file *file)

{

	lo->lo_backing_file = file;

	lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping);

	mapping_set_gfp_mask(file->f_mapping,

			lo->old_gfp_mask & ~(__GFP_IO | __GFP_FS));

}



/*

 * loop_change_fd switched the backing store of a loopback device to

 * a new file. This is useful for operating system installers to free up
@@ -626,10 +634,7 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, 
	disk_force_media_change(lo->lo_disk);

	memflags = blk_mq_freeze_queue(lo->lo_queue);

	mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);

	lo->lo_backing_file = file;

	lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping);

	mapping_set_gfp_mask(file->f_mapping,

			     lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));

	loop_assign_backing_file(lo, file);

	loop_update_dio(lo);

	blk_mq_unfreeze_queue(lo->lo_queue, memflags);

	partscan = lo->lo_flags & LO_FLAGS_PARTSCAN;
@@ -1019,7 +1024,6 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
			  const struct loop_config *config)

{

	struct file *file = fget(config->fd);

	struct address_space *mapping;

	struct queue_limits lim;

	int error;

	loff_t size;
@@ -1055,8 +1059,6 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
	if (error)

		goto out_unlock;



	mapping = file->f_mapping;



	if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) {

		error = -EINVAL;

		goto out_unlock;
@@ -1088,9 +1090,7 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
	set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);



	lo->lo_device = bdev;

	lo->lo_backing_file = file;

	lo->old_gfp_mask = mapping_gfp_mask(mapping);

	mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));

	loop_assign_backing_file(lo, file);



	lim = queue_limits_start_update(lo->lo_queue);

	loop_update_limits(lo, &lim, config->block_size);