Commit afd69d5c authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: remove the use_dio field in struct loop_device 



This field duplicate the LO_FLAGS_DIRECT_IO flag in lo_flags.  Remove it
to have a single source of truth about using direct I/O.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-9-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0cd719aa

drivers/block/loop.c

+17 −22
Original line number Diff line number Diff line
@@ -68,7 +68,6 @@ struct loop_device { 
	struct list_head        idle_worker_list;

	struct rb_root          worker_tree;

	struct timer_list       timer;

	bool			use_dio;

	bool			sysfs_inited;



	struct request_queue	*lo_queue;
@@ -196,32 +195,30 @@ static bool lo_can_use_dio(struct loop_device *lo) 
	return true;

}



/*

 * Direct I/O can be enabled either by using an O_DIRECT file descriptor, or by

 * passing in the LO_FLAGS_DIRECT_IO flag from userspace.  It will be silently

 * disabled when the device block size is too small or the offset is unaligned.

 *

 * loop_get_status will always report the effective LO_FLAGS_DIRECT_IO flag and

 * not the originally passed in one.

 */

static inline void loop_update_dio(struct loop_device *lo)

{

	bool dio = lo->use_dio || (lo->lo_backing_file->f_flags & O_DIRECT);

	bool use_dio = dio && lo_can_use_dio(lo);

	bool dio_in_use = lo->lo_flags & LO_FLAGS_DIRECT_IO;



	lockdep_assert_held(&lo->lo_mutex);

	WARN_ON_ONCE(lo->lo_state == Lo_bound &&

		     lo->lo_queue->mq_freeze_depth == 0);



	if (lo->use_dio == use_dio)

		return;



	/* flush dirty pages before starting to use direct I/O */

	if (use_dio)

		vfs_fsync(lo->lo_backing_file, 0);



	/*

	 * The flag of LO_FLAGS_DIRECT_IO is handled similarly with

	 * LO_FLAGS_READ_ONLY, both are set from kernel, and losetup

	 * will get updated by ioctl(LOOP_GET_STATUS)

	 */

	lo->use_dio = use_dio;

	if (use_dio)

	if (lo->lo_backing_file->f_flags & O_DIRECT)

		lo->lo_flags |= LO_FLAGS_DIRECT_IO;

	else

	if ((lo->lo_flags & LO_FLAGS_DIRECT_IO) && !lo_can_use_dio(lo))

		lo->lo_flags &= ~LO_FLAGS_DIRECT_IO;



	/* flush dirty pages before starting to issue direct I/O */

	if ((lo->lo_flags & LO_FLAGS_DIRECT_IO) && !dio_in_use)

		vfs_fsync(lo->lo_backing_file, 0);

}



/**
@@ -1089,7 +1086,6 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
	disk_force_media_change(lo->lo_disk);

	set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);



	lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO;

	lo->lo_device = bdev;

	lo->lo_backing_file = file;

	lo->old_gfp_mask = mapping_gfp_mask(mapping);
@@ -1454,7 +1450,7 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) 


	if (lo->lo_state != Lo_bound)

		return -ENXIO;

	if (use_dio == lo->use_dio)

	if (use_dio == !!(lo->lo_flags & LO_FLAGS_DIRECT_IO))

		return 0;



	if (use_dio) {
@@ -1465,7 +1461,6 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) 
	}



	blk_mq_freeze_queue(lo->lo_queue);

	lo->use_dio = use_dio;

	if (use_dio)

		lo->lo_flags |= LO_FLAGS_DIRECT_IO;

	else
@@ -1876,7 +1871,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, 
		cmd->use_aio = false;

		break;

	default:

		cmd->use_aio = lo->use_dio;

		cmd->use_aio = lo->lo_flags & LO_FLAGS_DIRECT_IO;

		break;

	}