Commit b38c8be2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: refactor queue limits updates 



Replace loop_reconfigure_limits with a slightly less encompassing
loop_update_limits that expects the caller to acquire and commit the
queue limits to prepare for sorting out the freeze vs limits lock
ordering.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarNilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250110054726.1499538-11-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1233751f

drivers/block/loop.c

+20 −16
Original line number Diff line number Diff line
@@ -977,12 +977,12 @@ static unsigned int loop_default_blocksize(struct loop_device *lo, 
	return SECTOR_SIZE;

}



static int loop_reconfigure_limits(struct loop_device *lo, unsigned int bsize)

static void loop_update_limits(struct loop_device *lo, struct queue_limits *lim,

		unsigned int bsize)

{

	struct file *file = lo->lo_backing_file;

	struct inode *inode = file->f_mapping->host;

	struct block_device *backing_bdev = NULL;

	struct queue_limits lim;

	u32 granularity = 0, max_discard_sectors = 0;



	if (S_ISBLK(inode->i_mode))
@@ -995,22 +995,20 @@ static int loop_reconfigure_limits(struct loop_device *lo, unsigned int bsize) 


	loop_get_discard_config(lo, &granularity, &max_discard_sectors);



	lim = queue_limits_start_update(lo->lo_queue);

	lim.logical_block_size = bsize;

	lim.physical_block_size = bsize;

	lim.io_min = bsize;

	lim.features &= ~(BLK_FEAT_WRITE_CACHE | BLK_FEAT_ROTATIONAL);

	lim->logical_block_size = bsize;

	lim->physical_block_size = bsize;

	lim->io_min = bsize;

	lim->features &= ~(BLK_FEAT_WRITE_CACHE | BLK_FEAT_ROTATIONAL);

	if (file->f_op->fsync && !(lo->lo_flags & LO_FLAGS_READ_ONLY))

		lim.features |= BLK_FEAT_WRITE_CACHE;

		lim->features |= BLK_FEAT_WRITE_CACHE;

	if (backing_bdev && !bdev_nonrot(backing_bdev))

		lim.features |= BLK_FEAT_ROTATIONAL;

	lim.max_hw_discard_sectors = max_discard_sectors;

	lim.max_write_zeroes_sectors = max_discard_sectors;

		lim->features |= BLK_FEAT_ROTATIONAL;

	lim->max_hw_discard_sectors = max_discard_sectors;

	lim->max_write_zeroes_sectors = max_discard_sectors;

	if (max_discard_sectors)

		lim.discard_granularity = granularity;

		lim->discard_granularity = granularity;

	else

		lim.discard_granularity = 0;

	return queue_limits_commit_update(lo->lo_queue, &lim);

		lim->discard_granularity = 0;

}



static int loop_configure(struct loop_device *lo, blk_mode_t mode,
@@ -1019,6 +1017,7 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
{

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

	struct address_space *mapping;

	struct queue_limits lim;

	int error;

	loff_t size;

	bool partscan;
@@ -1090,7 +1089,9 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, 
	lo->old_gfp_mask = mapping_gfp_mask(mapping);

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



	error = loop_reconfigure_limits(lo, config->block_size);

	lim = queue_limits_start_update(lo->lo_queue);

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

	error = queue_limits_commit_update(lo->lo_queue, &lim);

	if (error)

		goto out_unlock;
@@ -1458,6 +1459,7 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) 


static int loop_set_block_size(struct loop_device *lo, unsigned long arg)

{

	struct queue_limits lim;

	int err = 0;



	if (lo->lo_state != Lo_bound)
@@ -1470,7 +1472,9 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) 
	invalidate_bdev(lo->lo_device);



	blk_mq_freeze_queue(lo->lo_queue);

	err = loop_reconfigure_limits(lo, arg);

	lim = queue_limits_start_update(lo->lo_queue);

	loop_update_limits(lo, &lim, arg);

	err = queue_limits_commit_update(lo->lo_queue, &lim);

	loop_update_dio(lo);

	blk_mq_unfreeze_queue(lo->lo_queue);