fd9f4e62a3
bio_clone_fast() sets the cloned bio to have the same ->bi_bdev as the source bio. This means that when request-based dm called setup_clone(), the cloned bio had its ->bi_bdev pointing to the dm device. After Commit0b6e522cdc("blk-mq: use ->bi_bdev for I/O accounting") __blk_account_io_start() started using the request's ->bio->bi_bdev for I/O accounting, if it was set. This caused IO going to the underlying devices to use the dm device for their I/O accounting. Set up the proper ->bi_bdev in blk_rq_prep_clone based on the whole device bdev for the queue the request is cloned onto. Fixes:0b6e522cdc("blk-mq: use ->bi_bdev for I/O accounting") Reported-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> [hch: the commit message is mostly from a different patch from Benjamin] Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com> Link: https://lore.kernel.org/r/20220118070444.1241739-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.