[Drbd-dev] misc bio allocation cleanups

[Guoqing Jiang]

Hi Christoph,

I tried with latest for-5.12/block branch, and got below issue when 
trying to create raid1 array.

[   80.605832] BUG: kernel NULL pointer dereference, address: 
0000000000000018
[   80.606159] #PF: supervisor read access in kernel mode
[   80.606159] #PF: error_code(0x0000) - not-present page
[   80.606159] PGD 0 P4D 0
[   80.606159] Oops: 0000 [#1] SMP NOPTI
[   80.606159] CPU: 1 PID: 207 Comm: mdadm Not tainted 5.11.0-rc5+ #37
[   80.606159] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), 
BIOS 1.10.2-1ubuntu1 04/01/2014
[   80.606159] RIP: 0010:bdev_read_only+0x0/0x30
[   80.606159] Code: 89 df 5b 5d e9 71 21 e7 ff 81 e6 ff ff 0f 00 48 c7 
c7 40 99 d9 9e e8 0f e5 04 00 eb a0 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 
00 <80> 7f 18 00 b8 01 00 00 00 75 11 48 8b 97 60 03 00 00 48 8b 4a 40
[   80.606159] RSP: 0018:ffffb14f405dfd38 EFLAGS: 00000246
[   80.606159] RAX: 0000000000000000 RBX: ffff9b0e0863b018 RCX: 
ffff9b0e01edc000
[   80.606159] RDX: ffff9b0e01b54c00 RSI: ffff9b0e0863b000 RDI: 
0000000000000000
[   80.606159] RBP: ffff9b0e01272200 R08: 0000000000000000 R09: 
0000000000000000
[   80.606159] R10: ffffee978004da40 R11: 0000000000000cc0 R12: 
ffff9b0e0863b000
[   80.606159] R13: ffff9b0e01f2cc00 R14: ffff9b0e0863b000 R15: 
0000000000000000
[   80.606159] FS:  00007f522ec65740(0000) GS:ffff9b0e7bc80000(0000) 
knlGS:0000000000000000
[   80.606159] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   80.606159] CR2: 0000000000000018 CR3: 0000000001364000 CR4: 
00000000000006e0
[   80.606159] Call Trace:
[   80.606159]  bind_rdev_to_array+0x2f7/0x380
[   80.606159]  ? cred_has_capability+0x80/0x120
[   80.606159]  md_add_new_disk+0x204/0x630
[   80.606159]  ? security_capable+0x33/0x50
[   80.606159]  md_ioctl+0xee7/0x1690
[   80.606159]  ? selinux_file_ioctl+0x143/0x200
[   80.606159]  blkdev_ioctl+0x1ff/0x240
[   80.606159]  block_ioctl+0x34/0x40
[   80.606159]  __x64_sys_ioctl+0x89/0xc0
[   80.606159]  do_syscall_64+0x33/0x40
[   80.606159]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   80.606159] RIP: 0033:0x7f522e564317
[   80.606159] Code: b3 66 90 48 8b 05 71 4b 2d 00 64 c7 00 26 00 00 00 
48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 4b 2d 00 f7 d8 64 89 01 48
[   80.606159] RSP: 002b:00007ffc3abd96f8 EFLAGS: 00000246 ORIG_RAX: 
0000000000000010
[   80.606159] RAX: ffffffffffffffda RBX: 00005653ee690350 RCX: 
00007f522e564317
[   80.606159] RDX: 00005653ee694058 RSI: 0000000040140921 RDI: 
0000000000000004
[   80.606159] RBP: 00005653ee690410 R08: 00007f522e839db0 R09: 
0000000000000000
[   80.606159] R10: 00005653ee690010 R11: 0000000000000246 R12: 
0000000000000000
[   80.606159] R13: 0000000000000000 R14: 0000000000000000 R15: 
00005653ee694010
[   80.606159] Modules linked in:
[   80.606159] CR2: 0000000000000018
[   80.622996] ---[ end trace 22144b856a3c1001 ]---
[   80.623285] RIP: 0010:bdev_read_only+0x0/0x30
[   80.623501] Code: 89 df 5b 5d e9 71 21 e7 ff 81 e6 ff ff 0f 00 48 c7 
c7 40 99 d9 9e e8 0f e5 04 00 eb a0 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 
00 <80> 7f 18 00 b8 01 00 00 00 75 11 48 8b 97 60 03 00 00 48 8b 4a 40
[   80.624544] RSP: 0018:ffffb14f405dfd38 EFLAGS: 00000246
[   80.624788] RAX: 0000000000000000 RBX: ffff9b0e0863b018 RCX: 
ffff9b0e01edc000
[   80.625136] RDX: ffff9b0e01b54c00 RSI: ffff9b0e0863b000 RDI: 
0000000000000000
[   80.625449] RBP: ffff9b0e01272200 R08: 0000000000000000 R09: 
0000000000000000
[   80.625761] R10: ffffee978004da40 R11: 0000000000000cc0 R12: 
ffff9b0e0863b000
[   80.626112] R13: ffff9b0e01f2cc00 R14: ffff9b0e0863b000 R15: 
0000000000000000
[   80.626429] FS:  00007f522ec65740(0000) GS:ffff9b0e7bc80000(0000) 
knlGS:0000000000000000
[   80.626784] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   80.627035] CR2: 0000000000000018 CR3: 0000000001364000 CR4: 
00000000000006e0
Killed


Thanks,
Guoqing