From 7e81f99afd91c937f0e66dc135e26c1c4f78b003 Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Tue, 10 Mar 2020 14:12:30 +0100 Subject: [PATCH] loop: Only change blocksize when needed. Return early in loop_set_block_size() if the requested block size is identical to the one we already have; this avoids expensive calls to freeze the block queue. Reviewed-by: Christoph Hellwig Signed-off-by: Martijn Coenen Signed-off-by: Jens Axboe --- drivers/block/loop.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 739b372a5112..93b8d6047c14 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1539,16 +1539,16 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg)) return -EINVAL; - if (lo->lo_queue->limits.logical_block_size != arg) { - sync_blockdev(lo->lo_device); - kill_bdev(lo->lo_device); - } + if (lo->lo_queue->limits.logical_block_size == arg) + return 0; + + sync_blockdev(lo->lo_device); + kill_bdev(lo->lo_device); blk_mq_freeze_queue(lo->lo_queue); /* kill_bdev should have truncated all the pages */ - if (lo->lo_queue->limits.logical_block_size != arg && - lo->lo_device->bd_inode->i_mapping->nrpages) { + if (lo->lo_device->bd_inode->i_mapping->nrpages) { err = -EAGAIN; pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", __func__, lo->lo_number, lo->lo_file_name,