loop: replace kill_bdev with invalidate_bdev (f4bd34b1) · Commits · 戴 / test

When a filesystem is mounted on a loop device and on a loop ioctl LOOP_SET_STATUS64, because of kill_bdev, buffer_head mappings are getting destroyed. kill_bdev truncate_inode_pages truncate_inode_pages_range do_invalidatepage block_invalidatepage discard_buffer -->clear BH_Mapped flag sb_bread __bread_gfp bh = __getblk_gfp -->discard_buffer clear BH_Mapped flag __bread_slow submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)) --> hit this BUG_ON Fixes: ("loop: drop caches if offset or block_size are changed") Signed-off-by:

Zheng Bin <zhengbin13@huawei.com> Reviewed-by:

Christoph Hellwig <hch@lst.de> Reviewed-by:

Bart Van Assche <bvanassche@acm.org> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

drivers/block/loop.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1368,14 +1368,14 @@ loop_set_status(struct loop_device lo, const struct loop_info64 info)
		lo->lo_sizelimit != info->lo_sizelimit) {
		size_changed = true;
		sync_blockdev(lo->lo_device);
		kill_bdev(lo->lo_device);
		invalidate_bdev(lo->lo_device);
		}

		/* 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 kill_bdev(), try again */
		/* If any pages were dirtied after invalidate_bdev(), try again */
		err = -EAGAIN;
		pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n",
		__func__, lo->lo_number, lo->lo_file_name,
		@@ -1615,11 +1615,11 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg)
		return 0;

		sync_blockdev(lo->lo_device);
		kill_bdev(lo->lo_device);
		invalidate_bdev(lo->lo_device);

		blk_mq_freeze_queue(lo->lo_queue);

		/* kill_bdev should have truncated all the pages */
		/* 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) has still dirty pages (nrpages=%lu)\n",

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