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loop: remove the racy bd_inode->i_mapping->nrpages asserts

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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 <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220330052917.2566582-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-03-30 07:29:10 +02:00 committed by Jens Axboe
parent b15ed54694
commit 98ded54a33
1 changed files with 0 additions and 20 deletions
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20
drivers/block/loop.c
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@ -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;