From 98ded54a33839e7b8f8bed772e01a544f48e33a7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:10 +0200 Subject: [PATCH] loop: remove the racy bd_inode->i_mapping->nrpages asserts Nothing prevents a file system or userspace opener of the block device from redirtying the page right afte sync_blockdev returned. Fortunately data in the page cache during a block device change is mostly harmless anyway. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Tested-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220330052917.2566582-9-hch@lst.de Signed-off-by: Jens Axboe --- drivers/block/loop.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 98e12d2..610942e 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1271,15 +1271,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) /* I/O need to be drained during transfer transition */ blk_mq_freeze_queue(lo->lo_queue); - if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { - /* If any pages were dirtied after invalidate_bdev(), try again */ - err = -EAGAIN; - pr_warn("%s: loop%d (%s) still has dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - prev_lo_flags = lo->lo_flags; err = loop_set_status_from_info(lo, info); @@ -1490,21 +1481,10 @@ 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); - - /* invalidate_bdev should have truncated all the pages */ - if (lo->lo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: loop%d (%s) still has dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - blk_queue_logical_block_size(lo->lo_queue, arg); blk_queue_physical_block_size(lo->lo_queue, arg); blk_queue_io_min(lo->lo_queue, arg); loop_update_dio(lo); -out_unfreeze: blk_mq_unfreeze_queue(lo->lo_queue); return err; -- 2.7.4