57a13a5b81
The block layer can't support a block size larger than page size yet. And a block size that's too small or not a power of two won't work either. If a misconfigured device presents an invalid block size in configuration space, it will result in the kernel crash something like below: [ 506.154324] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 506.160416] RIP: 0010:create_empty_buffers+0x24/0x100 [ 506.174302] Call Trace: [ 506.174651] create_page_buffers+0x4d/0x60 [ 506.175207] block_read_full_page+0x50/0x380 [ 506.175798] ? __mod_lruvec_page_state+0x60/0xa0 [ 506.176412] ? __add_to_page_cache_locked+0x1b2/0x390 [ 506.177085] ? blkdev_direct_IO+0x4a0/0x4a0 [ 506.177644] ? scan_shadow_nodes+0x30/0x30 [ 506.178206] ? lru_cache_add+0x42/0x60 [ 506.178716] do_read_cache_page+0x695/0x740 [ 506.179278] ? read_part_sector+0xe0/0xe0 [ 506.179821] read_part_sector+0x36/0xe0 [ 506.180337] adfspart_check_ICS+0x32/0x320 [ 506.180890] ? snprintf+0x45/0x70 [ 506.181350] ? read_part_sector+0xe0/0xe0 [ 506.181906] bdev_disk_changed+0x229/0x5c0 [ 506.182483] blkdev_get_whole+0x6d/0x90 [ 506.183013] blkdev_get_by_dev+0x122/0x2d0 [ 506.183562] device_add_disk+0x39e/0x3c0 [ 506.184472] virtblk_probe+0x3f8/0x79b [virtio_blk] [ 506.185461] virtio_dev_probe+0x15e/0x1d0 [virtio] So let's use a block layer helper to validate the block size. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20211026144015.188-5-xieyongji@bytedance.com 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.