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| author | Takashi Iwai <tiwai@suse.de> | 2014-12-10 16:38:30 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-12-10 08:57:31 -0700 |
| commit | 06a41a99d13d8e919e9a00a4849e6b85ae492592 (patch) | |
| tree | 8812b9bebdbf8961d914be9b024af072676a78f3 /block | |
| parent | 7eca210375dcc029ad69c0cf48d2bf7a71f0121d (diff) | |
| download | linux-06a41a99d13d8e919e9a00a4849e6b85ae492592.tar.gz linux-06a41a99d13d8e919e9a00a4849e6b85ae492592.tar.bz2 linux-06a41a99d13d8e919e9a00a4849e6b85ae492592.zip | |
blk-mq: Fix uninitialized kobject at CPU hotplugging
When a CPU is hotplugged, the current blk-mq spews a warning like:
kobject '(null)' (ffffe8ffffc8b5d8): tried to add an uninitialized object, something is seriously wrong.
CPU: 1 PID: 1386 Comm: systemd-udevd Not tainted 3.18.0-rc7-2.g088d59b-default #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_171129-lamiak 04/01/2014
0000000000000000 0000000000000002 ffffffff81605f07 ffffe8ffffc8b5d8
ffffffff8132c7a0 ffff88023341d370 0000000000000020 ffff8800bb05bd58
ffff8800bb05bd08 000000000000a0a0 000000003f441940 0000000000000007
Call Trace:
[<ffffffff81005306>] dump_trace+0x86/0x330
[<ffffffff81005644>] show_stack_log_lvl+0x94/0x170
[<ffffffff81006d21>] show_stack+0x21/0x50
[<ffffffff81605f07>] dump_stack+0x41/0x51
[<ffffffff8132c7a0>] kobject_add+0xa0/0xb0
[<ffffffff8130aee1>] blk_mq_register_hctx+0x91/0xb0
[<ffffffff8130b82e>] blk_mq_sysfs_register+0x3e/0x60
[<ffffffff81309298>] blk_mq_queue_reinit_notify+0xf8/0x190
[<ffffffff8107cfdc>] notifier_call_chain+0x4c/0x70
[<ffffffff8105fd23>] cpu_notify+0x23/0x50
[<ffffffff81060037>] _cpu_up+0x157/0x170
[<ffffffff810600d9>] cpu_up+0x89/0xb0
[<ffffffff815fa5b5>] cpu_subsys_online+0x35/0x80
[<ffffffff814323cd>] device_online+0x5d/0xa0
[<ffffffff81432485>] online_store+0x75/0x80
[<ffffffff81236a5a>] kernfs_fop_write+0xda/0x150
[<ffffffff811c5532>] vfs_write+0xb2/0x1f0
[<ffffffff811c5f42>] SyS_write+0x42/0xb0
[<ffffffff8160c4ed>] system_call_fastpath+0x16/0x1b
[<00007f0132fb24e0>] 0x7f0132fb24e0
This is indeed because of an uninitialized kobject for blk_mq_ctx.
The blk_mq_ctx kobjects are initialized in blk_mq_sysfs_init(), but it
goes loop over hctx_for_each_ctx(), i.e. it initializes only for
online CPUs. Thus, when a CPU is hotplugged, the ctx for the newly
onlined CPU is registered without initialization.
This patch fixes the issue by initializing the all ctx kobjects
belonging to each queue.
Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=908794
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-sysfs.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 371d8800b48a..1630a20d5dcf 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -390,16 +390,15 @@ static void blk_mq_sysfs_init(struct request_queue *q) { struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; - int i, j; + int i; kobject_init(&q->mq_kobj, &blk_mq_ktype); - queue_for_each_hw_ctx(q, hctx, i) { + queue_for_each_hw_ctx(q, hctx, i) kobject_init(&hctx->kobj, &blk_mq_hw_ktype); - hctx_for_each_ctx(hctx, ctx, j) - kobject_init(&ctx->kobj, &blk_mq_ctx_ktype); - } + queue_for_each_ctx(q, ctx, i) + kobject_init(&ctx->kobj, &blk_mq_ctx_ktype); } /* see blk_register_queue() */ |