On 3/30/2023 4:02 PM, Jens Axboe wrote:
> Please take Damien's advice from v1 and compact these patches. This is
> getting somewhat out of hand and silly, imho. Are we gaming patch
> counts?! If not, what's the point?
>
okay, but it's not true with the patch-count here is how I got here :-
Last year I started testing poll queues for null_blk and found an OOPs
[1]. Then I fixed an OOPs with adding single parameter check, curiously
I also looked around other parameters such as bs, submit_queues, gb,
max_sector, queue_depth to see if I can add similar fix. As I moved
forward with testing with each parameter I wrote a testcase and then
wrote a patch for specific parameter because for poll_queue it was
fixing OOPs and now it is a warn message [2] that's why I still think
is a fix.
So how can I mix poll_queue fix with other code which has nothing to
do with the fix ? since a fix needs to be isolated and not mixed up with
new functionality I kept everything isolated into their own patches,
also keeping check isolated allows us to print the right error
message instead of just -EINVAL with reference to V2.
Clearly that is not how things to be done, as per your suggestion
I'll make a single patch for all the checks.
I should have sent a fix alone then do the fixing for rest params later
2-3 patches that's my mistake.
I truly believe that testing and finding bugs adds more value than
increasing patch count, that is how I found an OOPs in my testing and
wrote a testcase(s) for that, it is in commit log. Amount of testing
I've done for this is really not worth a patch count but definitely
worth a blktests :).
On the similar note I'll also trim the brd series.
-ck
[1] Entering kdb (current=0xffff88817eaed100, pid 5624) on processor 12
Oops: (null)
due to oops @ 0xffffffff8165093f
CPU: 12 PID: 5624 Comm: modprobe Tainted: G OE
6.0.0-rc7blk+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:blk_mq_alloc_tag_set+0x14f/0x380
Code: 83 c5 01 3b 6b 40 0f 83 9a 01 00 00 48 8b 43 68 4c 63 e5 4e 8d 34
e0 f6 43 58 08 75 d7 8b 53 44 89 ee 48 89 df e8 d1 ed ff ff <49> 89 06
48 8b 43 68 4a 83 3c e0 00 75 c3 83 ed 01 78 0f 89 ee 48
RSP: 0018:ffffc90002eefd70 EFLAGS: 00010282
RAX: ffff888112b155c0 RBX: ffff88811069dc38 RCX: 0000000000000003
RDX: ffff88811069d000 RSI: ffff88810ed60000 RDI: 00000000000001f8
RBP: 0000000000000000 R08: 0000000000000003 R09: ffff888112b15650
R10: 000000000010ed60 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000040 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f71e4147b80(0000) GS:ffff888fff500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000014d81c000 CR4: 0000000000350ee0
Call Trace:
<TASK>
null_add_dev+0x7a7/0x870 [null_blk]
null_init+0x1de/0x1000 [null_blk]
? 0xffffffffc03a9000
do_one_initcall+0x44/0x210
? kmem_cache_alloc_trace+0x15b/0x2b0
do_init_module+0x4c/0x1f0
__do_sys_finit_module+0xb4/0x130
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f71e426e15d
Code: c5 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
f0 ff ff 73 01 c3 48 8b 0d e3 7c 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007fffb29f27a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 0000564b29d78b90 RCX: 00007f71e426e15d
RDX: 0000000000000000 RSI: 0000564b29d78f00 RDI: 0000000000000003
RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000020
R10: 0000000000000003 R11: 0000000000000246 R12: 0000564b29d78f00
R13: 0000564b29d78cc0 R14: 0000564b29d78b90 R15: 0000564b29d78f20
</TASK>
[2]
modprobe null_blk poll_queues=64
[29808.758787] ------------[ cut here ]------------
[29808.758790] WARNING: CPU: 27 PID: 41164 at lib/group_cpus.c:400
group_cpus_evenly+0x26e/0x280
[29808.758798] Modules linked in: null_blk(O+) xt_state xt_conntrack
nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 uinput nvme(O) nvme_core(O)
nvme_common snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer
snd soundcore ip6table_mangle ip6table_raw ip6table_security
iptable_mangle iptable_raw iptable_security ip_set nf_tables rfkill
nfnetlink ip6table_filter ip6_tables iptable_filter tun sunrpc
intel_rapl_msr intel_rapl_common xfs kvm_amd ppdev ccp kvm parport_pc
parport irqbypass pcspkr joydev i2c_piix4 zram ip_tables bochs
drm_vram_helper crct10dif_pclmul crc32_pclmul drm_kms_helper
crc32c_intel drm_ttm_helper ghash_clmulni_intel ttm sha512_ssse3
virtio_net net_failover serio_raw virtio_blk drm failover ata_generic
pata_acpi qemu_fw_cfg fuse [last unloaded: null_blk(O)]
[29808.758850] CPU: 27 PID: 41164 Comm: modprobe Tainted: G W O
N 6.3.0-rc1lblk+ #2
[29808.758853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[29808.758855] RIP: 0010:group_cpus_evenly+0x26e/0x280
[29808.758858] Code: b1 ff 48 8b 7c 24 08 e8 20 d1 5d 00 48 8b 3c 24 e8
17 d1 5d 00 45 85 ed 0f 89 01 fe ff ff e9 f1 fd ff ff e8 b4 9d 8d ff eb
ac <0f> 0b eb a8 e8 39 c4 60 00 41 bd f4 ff ff ff eb 9b cc 90 90 90 90
[29808.758860] RSP: 0018:ffffc90000f4bcb8 EFLAGS: 00010287
[29808.758862] RAX: 0000000080000000 RBX: 0000000000000040 RCX:
0000000000000000
[29808.758864] RDX: 0000000000000001 RSI: 0000000000000030 RDI:
00000000ffffffff
[29808.758865] RBP: ffff8888535b2668 R08: ffff8888535b2150 R09:
ffff8888c3fa0000
[29808.758866] R10: ffff8888535b2150 R11: 0000000000000000 R12:
ffff8888c3fa0000
[29808.758868] R13: 0000000000000000 R14: 0000000000000030 R15:
0000000000000000
[29808.758871] FS: 00007f00bda3eb80(0000) GS:ffff888fff8c0000(0000)
knlGS:0000000000000000
[29808.758873] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[29808.758875] CR2: 00007f00bd506800 CR3: 00000008330cc000 CR4:
0000000000350ee0
[29808.758878] DR0: ffffffff843793e1 DR1: ffffffff843793e2 DR2:
ffffffff843793e3
[29808.758879] DR3: ffffffff8437944f DR6: 00000000ffff0ff0 DR7:
0000000000000600
[29808.758880] Call Trace:
[29808.758883] <TASK>
[29808.758888] blk_mq_map_queues+0x16/0xc0
[29808.758893] null_map_queues+0xa5/0xe0 [null_blk]
[29808.758903] blk_mq_alloc_tag_set+0x14d/0x3f0
[29808.758907] ? __kmalloc+0xbc/0x130
[29808.758911] null_add_dev.part.0+0x601/0x700 [null_blk]
[29808.758920] null_init+0x109/0xff0 [null_blk]
[29808.758929] ? __pfx_init_module+0x10/0x10 [null_blk]
[29808.758937] do_one_initcall+0x44/0x220
[29808.758942] ? kmalloc_trace+0x25/0x90
[29808.758945] do_init_module+0x4c/0x210
[29808.758949] __do_sys_finit_module+0xb4/0x130
[29808.758955] do_syscall_64+0x3b/0x90
[29808.758959] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[29808.758963] RIP: 0033:0x7f00bd52c15d
[29808.758965] Code: c5 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa
48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 7c 0c 00 f7 d8 64 89 01 48
[29808.758967] RSP: 002b:00007ffdc8b239b8 EFLAGS: 00000246 ORIG_RAX:
0000000000000139
[29808.758969] RAX: ffffffffffffffda RBX: 0000559f27d02b90 RCX:
00007f00bd52c15d
[29808.758970] RDX: 0000000000000000 RSI: 0000559f27d02f00 RDI:
0000000000000003
[29808.758971] RBP: 0000000000040000 R08: 0000000000000000 R09:
0000000000000020
[29808.758972] R10: 0000000000000003 R11: 0000000000000246 R12:
0000559f27d02f00
[29808.758973] R13: 0000559f27d02cc0 R14: 0000559f27d02b90 R15:
0000559f27d02f20
[29808.758976] </TASK>
[29808.758977] ---[ end trace 0000000000000000 ]---
