Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: rename ->make_request_fn and move it to the
 block_device_operations
From:   Jens Axboe <axboe@kernel.dk>
To:     Christoph Hellwig <hch@lst.de>
Cc:     dm-devel@redhat.com, linux-kernel@vger.kernel.org,
        linux-m68k@lists.linux-m68k.org, linux-xtensa@linux-xtensa.org,
        drbd-dev@lists.linbit.com, linuxppc-dev@lists.ozlabs.org,
        linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org,
        linux-nvdimm@lists.01.org, linux-nvme@lists.infradead.org,
        linux-s390@vger.kernel.org
References: <20200629193947.2705954-1-hch@lst.de>
 <bd1443c0-be37-115b-1110-df6f0e661a50@kernel.dk>
Message-ID: <6ddbe343-0fc2-58c8-3726-c4ba9952994f@kernel.dk>
Date:   Tue, 30 Jun 2020 09:43:31 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.8.0
MIME-Version: 1.0
In-Reply-To: <bd1443c0-be37-115b-1110-df6f0e661a50@kernel.dk>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 6/30/20 7:57 AM, Jens Axboe wrote:
> On 6/29/20 1:39 PM, Christoph Hellwig wrote:
>> Hi Jens,
>>
>> this series moves the make_request_fn method into block_device_operations
>> with the much more descriptive ->submit_bio name.  It then also gives
>> generic_make_request a more descriptive name, and further optimize the
>> path to issue to blk-mq, removing the need for the direct_make_request
>> bypass.
> 
> Looks good to me, and it's a nice cleanup as well. Applied.

Dropped, insta-crashes with dm:

[   10.240134] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   10.241000] #PF: supervisor instruction fetch in kernel mode
[   10.241666] #PF: error_code(0x0010) - not-present page
[   10.242280] PGD 0 P4D 0 
[   10.242600] Oops: 0010 [#1] PREEMPT SMP
[   10.243073] CPU: 1 PID: 2110 Comm: systemd-udevd Not tainted 5.8.0-rc3+ #6655
[   10.243939] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
[   10.245012] RIP: 0010:0x0
[   10.245322] Code: Bad RIP value.
[   10.245695] RSP: 0018:ffffc900002f7af8 EFLAGS: 00010246
[   10.246333] RAX: ffffffff81c83520 RBX: ffff8881b805dea8 RCX: ffff88819e844070
[   10.247227] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88819e844070
[   10.248112] RBP: ffffc900002f7b48 R08: ffff8881b6f38800 R09: ffff88818ff0ea58
[   10.248994] R10: 0000000000000000 R11: ffff88818ff0ea58 R12: ffff88819e844070
[   10.250077] R13: 00000000ffffffff R14: 0000000000000000 R15: ffff888107812948
[   10.251168] FS:  00007f5c3ed66a80(0000) GS:ffff8881b9c80000(0000) knlGS:0000000000000000
[   10.252161] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   10.253189] CR2: ffffffffffffffd6 CR3: 00000001b2953003 CR4: 00000000001606e0
[   10.254157] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   10.255279] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   10.256365] Call Trace:
[   10.256781]  submit_bio_noacct+0x1f6/0x3d0
[   10.257297]  submit_bio+0x37/0x130
[   10.257780]  ? guard_bio_eod+0x2e/0x70
[   10.258418]  mpage_readahead+0x13c/0x180
[   10.259096]  ? blkdev_direct_IO+0x490/0x490
[   10.259654]  read_pages+0x68/0x2d0
[   10.260051]  page_cache_readahead_unbounded+0x1b7/0x220
[   10.260818]  generic_file_buffered_read+0x865/0xc80
[   10.261587]  ? _copy_to_user+0x6d/0x80
[   10.262171]  ? cp_new_stat+0x119/0x130
[   10.262680]  new_sync_read+0xfe/0x170
[   10.263155]  vfs_read+0xc8/0x180
[   10.263647]  ksys_read+0x53/0xc0
[   10.264209]  do_syscall_64+0x3c/0x70
[   10.264759]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   10.265200] RIP: 0033:0x7f5c3fcc9ab2
[   10.265510] Code: Bad RIP value.
[   10.265775] RSP: 002b:00007ffc8e0cf9c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[   10.266426] RAX: ffffffffffffffda RBX: 000055d5eca76c68 RCX: 00007f5c3fcc9ab2
[   10.267012] RDX: 0000000000000040 RSI: 000055d5eca76c78 RDI: 0000000000000006
[   10.267591] RBP: 000055d5eca44890 R08: 000055d5eca76c50 R09: 00007f5c3fd99a40
[   10.268168] R10: 0000000000000008 R11: 0000000000000246 R12: 000000003bd90000
[   10.268744] R13: 0000000000000040 R14: 000055d5eca76c50 R15: 000055d5eca448e0
[   10.269319] Modules linked in:
[   10.269562] CR2: 0000000000000000
[   10.269845] ---[ end trace f09b8963e5a3593b ]---

-- 
Jens Axboe