* WARNING: at block/blk-cgroup.c:867
@ 2012-06-01 11:29 Heiko Carstens
2012-06-04 4:30 ` [PATCH 1/2] block: fix return value on cfq_init() failure Tejun Heo
0 siblings, 1 reply; 4+ messages in thread
From: Heiko Carstens @ 2012-06-01 11:29 UTC (permalink / raw)
To: Tejun Heo, Jens Axboe; +Cc: linux-kernel
Hi Tejun,
for !CONFIG_CFQ_GROUP_IOSCHED the following warning triggered on s390:
------------[ cut here ]------------
WARNING: at block/blk-cgroup.c:867
Modules linked in:
Modules linked in:
CPU: 3 Not tainted 3.4.0-09547-gfb21aff #1
Process swapper/0 (pid: 1, task: 000000003ff80000, ksp: 000000003ff7f8b8)
Krnl PSW : 0704100180000000 00000000003d76ca (blkcg_policy_register+0xca/0xe0)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3
Krnl GPRS: 0000000000000000 00000000014b85ec 00000000014b85b0 0000000000000000
000000000096fb60 0000000000000000 00000000009a8e78 0000000000000048
000000000099c070 0000000000b6f000 0000000000000000 000000000099c0b8
00000000014b85b0 0000000000667580 000000003ff7fd98 000000003ff7fd70
Krnl Code: 00000000003d76be: a7280001 lhi %r2,1
00000000003d76c2: a7f4ffdf brc 15,3d7680
#00000000003d76c6: a7f40001 brc 15,3d76c8
>00000000003d76ca: a7c8ffea lhi %r12,-22
00000000003d76ce: a7f4ffce brc 15,3d766a
00000000003d76d2: a7f40001 brc 15,3d76d4
00000000003d76d6: a7c80000 lhi %r12,0
00000000003d76da: a7f4ffc2 brc 15,3d765e
Call Trace:
([<0000000000b6f000>] initcall_debug+0x0/0x4)
[<0000000000989e8a>] cfq_init+0x62/0xd4
[<00000000001000ba>] do_one_initcall+0x3a/0x170
[<000000000096fb60>] kernel_init+0x214/0x2bc
[<0000000000623202>] kernel_thread_starter+0x6/0xc
[<00000000006231fc>] kernel_thread_starter+0x0/0xc
no locks held by swapper/0/1.
Last Breaking-Event-Address:
[<00000000003d76c6>] blkcg_policy_register+0xc6/0xe0
---[ end trace b8ef4903fcbf9dd3 ]---
for !CONFIG_CFQ_GROUP_IOSCHED the blkcg_policy_cfq that cfq_init() tries to
register with blkcg_policy_register() is in the bss section and therefore
initialized with 0.
So the warning in blkcg_policy_register()
if (WARN_ON(pol->pd_size < sizeof(struct blkg_policy_data)))
return -EINVAL;
will trigger since pd_size == 0.
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH 1/2] block: fix return value on cfq_init() failure 2012-06-01 11:29 WARNING: at block/blk-cgroup.c:867 Heiko Carstens @ 2012-06-04 4:30 ` Tejun Heo 2012-06-04 4:31 ` [PATCH 2/2] block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED Tejun Heo 0 siblings, 1 reply; 4+ messages in thread From: Tejun Heo @ 2012-06-04 4:30 UTC (permalink / raw) To: Jens Axboe, Heiko Carstens; +Cc: linux-kernel cfq_init() would return zero after kmem cache creation failure. Fix so that it returns -ENOMEM. Signed-off-by: Tejun Heo <tj@kernel.org> --- block/cfq-iosched.c | 1 + 1 file changed, 1 insertion(+) --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -4202,6 +4202,7 @@ static int __init cfq_init(void) if (ret) return ret; + ret = -ENOMEM; cfq_pool = KMEM_CACHE(cfq_queue, 0); if (!cfq_pool) goto err_pol_unreg; ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 2/2] block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED 2012-06-04 4:30 ` [PATCH 1/2] block: fix return value on cfq_init() failure Tejun Heo @ 2012-06-04 4:31 ` Tejun Heo 2012-06-04 13:23 ` Jens Axboe 0 siblings, 1 reply; 4+ messages in thread From: Tejun Heo @ 2012-06-04 4:31 UTC (permalink / raw) To: Jens Axboe, Heiko Carstens; +Cc: linux-kernel cfq may be built w/ or w/o blkcg support depending on CONFIG_CFQ_CGROUP_IOSCHED. If blkcg support is disabled, most of related code is ifdef'd out but some part is left dangling - blkcg_policy_cfq is left zero-filled and blkcg_policy_[un]register() calls are made on it. Feeding zero filled policy to blkcg_policy_register() is incorrect and triggers the following WARN_ON() if CONFIG_BLK_CGROUP && !CONFIG_CFQ_GROUP_IOSCHED. ------------[ cut here ]------------ WARNING: at block/blk-cgroup.c:867 Modules linked in: Modules linked in: CPU: 3 Not tainted 3.4.0-09547-gfb21aff #1 Process swapper/0 (pid: 1, task: 000000003ff80000, ksp: 000000003ff7f8b8) Krnl PSW : 0704100180000000 00000000003d76ca (blkcg_policy_register+0xca/0xe0) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3 Krnl GPRS: 0000000000000000 00000000014b85ec 00000000014b85b0 0000000000000000 000000000096fb60 0000000000000000 00000000009a8e78 0000000000000048 000000000099c070 0000000000b6f000 0000000000000000 000000000099c0b8 00000000014b85b0 0000000000667580 000000003ff7fd98 000000003ff7fd70 Krnl Code: 00000000003d76be: a7280001 lhi %r2,1 00000000003d76c2: a7f4ffdf brc 15,3d7680 #00000000003d76c6: a7f40001 brc 15,3d76c8 >00000000003d76ca: a7c8ffea lhi %r12,-22 00000000003d76ce: a7f4ffce brc 15,3d766a 00000000003d76d2: a7f40001 brc 15,3d76d4 00000000003d76d6: a7c80000 lhi %r12,0 00000000003d76da: a7f4ffc2 brc 15,3d765e Call Trace: ([<0000000000b6f000>] initcall_debug+0x0/0x4) [<0000000000989e8a>] cfq_init+0x62/0xd4 [<00000000001000ba>] do_one_initcall+0x3a/0x170 [<000000000096fb60>] kernel_init+0x214/0x2bc [<0000000000623202>] kernel_thread_starter+0x6/0xc [<00000000006231fc>] kernel_thread_starter+0x0/0xc no locks held by swapper/0/1. Last Breaking-Event-Address: [<00000000003d76c6>] blkcg_policy_register+0xc6/0xe0 ---[ end trace b8ef4903fcbf9dd3 ]--- This patch fixes the problem by ensuring all blkcg support code is inside CONFIG_CFQ_GROUP_IOSCHED. * blkcg_policy_cfq declaration and blkg_to_cfqg() definition are moved inside the first CONFIG_CFQ_GROUP_IOSCHED block. __maybe_unused is dropped from blkcg_policy_cfq decl. * blkcg_deactivate_poilcy() invocation is moved inside ifdef. This also makes the activation logic match cfq_init_queue(). * All blkcg_policy_[un]register() invocations are moved inside ifdef. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> LKML-Reference: <20120601112954.GC3535@osiris.boeblingen.de.ibm.com> --- block/cfq-iosched.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -17,8 +17,6 @@ #include "blk.h" #include "blk-cgroup.h" -static struct blkcg_policy blkcg_policy_cfq __maybe_unused; - /* * tunables */ @@ -418,11 +416,6 @@ static inline struct cfq_group *pd_to_cf return pd ? container_of(pd, struct cfq_group, pd) : NULL; } -static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) -{ - return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); -} - static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) { return pd_to_blkg(&cfqg->pd); @@ -572,6 +565,13 @@ static inline void cfqg_stats_update_avg #ifdef CONFIG_CFQ_GROUP_IOSCHED +static struct blkcg_policy blkcg_policy_cfq; + +static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) +{ + return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); +} + static inline void cfqg_get(struct cfq_group *cfqg) { return blkg_get(cfqg_to_blkg(cfqg)); @@ -3951,10 +3951,11 @@ static void cfq_exit_queue(struct elevat cfq_shutdown_timer_wq(cfqd); -#ifndef CONFIG_CFQ_GROUP_IOSCHED +#ifdef CONFIG_CFQ_GROUP_IOSCHED + blkcg_deactivate_policy(q, &blkcg_policy_cfq); +#else kfree(cfqd->root_group); #endif - blkcg_deactivate_policy(q, &blkcg_policy_cfq); kfree(cfqd); } @@ -4194,13 +4195,13 @@ static int __init cfq_init(void) #ifdef CONFIG_CFQ_GROUP_IOSCHED if (!cfq_group_idle) cfq_group_idle = 1; -#else - cfq_group_idle = 0; -#endif ret = blkcg_policy_register(&blkcg_policy_cfq); if (ret) return ret; +#else + cfq_group_idle = 0; +#endif ret = -ENOMEM; cfq_pool = KMEM_CACHE(cfq_queue, 0); @@ -4216,13 +4217,17 @@ static int __init cfq_init(void) err_free_pool: kmem_cache_destroy(cfq_pool); err_pol_unreg: +#ifdef CONFIG_CFQ_GROUP_IOSCHED blkcg_policy_unregister(&blkcg_policy_cfq); +#endif return ret; } static void __exit cfq_exit(void) { +#ifdef CONFIG_CFQ_GROUP_IOSCHED blkcg_policy_unregister(&blkcg_policy_cfq); +#endif elv_unregister(&iosched_cfq); kmem_cache_destroy(cfq_pool); } ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED 2012-06-04 4:31 ` [PATCH 2/2] block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED Tejun Heo @ 2012-06-04 13:23 ` Jens Axboe 0 siblings, 0 replies; 4+ messages in thread From: Jens Axboe @ 2012-06-04 13:23 UTC (permalink / raw) To: Tejun Heo; +Cc: Heiko Carstens, linux-kernel@vger.kernel.org On 06/04/2012 06:31 AM, Tejun Heo wrote: > cfq may be built w/ or w/o blkcg support depending on > CONFIG_CFQ_CGROUP_IOSCHED. If blkcg support is disabled, most of > related code is ifdef'd out but some part is left dangling - > blkcg_policy_cfq is left zero-filled and blkcg_policy_[un]register() > calls are made on it. > > Feeding zero filled policy to blkcg_policy_register() is incorrect and > triggers the following WARN_ON() if CONFIG_BLK_CGROUP && > !CONFIG_CFQ_GROUP_IOSCHED. > > ------------[ cut here ]------------ > WARNING: at block/blk-cgroup.c:867 > Modules linked in: > Modules linked in: > CPU: 3 Not tainted 3.4.0-09547-gfb21aff #1 > Process swapper/0 (pid: 1, task: 000000003ff80000, ksp: 000000003ff7f8b8) > Krnl PSW : 0704100180000000 00000000003d76ca (blkcg_policy_register+0xca/0xe0) > R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3 > Krnl GPRS: 0000000000000000 00000000014b85ec 00000000014b85b0 0000000000000000 > 000000000096fb60 0000000000000000 00000000009a8e78 0000000000000048 > 000000000099c070 0000000000b6f000 0000000000000000 000000000099c0b8 > 00000000014b85b0 0000000000667580 000000003ff7fd98 000000003ff7fd70 > Krnl Code: 00000000003d76be: a7280001 lhi %r2,1 > 00000000003d76c2: a7f4ffdf brc 15,3d7680 > #00000000003d76c6: a7f40001 brc 15,3d76c8 > >00000000003d76ca: a7c8ffea lhi %r12,-22 > 00000000003d76ce: a7f4ffce brc 15,3d766a > 00000000003d76d2: a7f40001 brc 15,3d76d4 > 00000000003d76d6: a7c80000 lhi %r12,0 > 00000000003d76da: a7f4ffc2 brc 15,3d765e > Call Trace: > ([<0000000000b6f000>] initcall_debug+0x0/0x4) > [<0000000000989e8a>] cfq_init+0x62/0xd4 > [<00000000001000ba>] do_one_initcall+0x3a/0x170 > [<000000000096fb60>] kernel_init+0x214/0x2bc > [<0000000000623202>] kernel_thread_starter+0x6/0xc > [<00000000006231fc>] kernel_thread_starter+0x0/0xc > no locks held by swapper/0/1. > Last Breaking-Event-Address: > [<00000000003d76c6>] blkcg_policy_register+0xc6/0xe0 > ---[ end trace b8ef4903fcbf9dd3 ]--- > > This patch fixes the problem by ensuring all blkcg support code is > inside CONFIG_CFQ_GROUP_IOSCHED. > > * blkcg_policy_cfq declaration and blkg_to_cfqg() definition are moved > inside the first CONFIG_CFQ_GROUP_IOSCHED block. __maybe_unused is > dropped from blkcg_policy_cfq decl. > > * blkcg_deactivate_poilcy() invocation is moved inside ifdef. This > also makes the activation logic match cfq_init_queue(). > > * All blkcg_policy_[un]register() invocations are moved inside ifdef. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> > LKML-Reference: <20120601112954.GC3535@osiris.boeblingen.de.ibm.com> Thanks Tejun, applied this one and 1/2 as well as a standalone bug fix. -- Jens Axboe ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-06-04 13:23 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-06-01 11:29 WARNING: at block/blk-cgroup.c:867 Heiko Carstens 2012-06-04 4:30 ` [PATCH 1/2] block: fix return value on cfq_init() failure Tejun Heo 2012-06-04 4:31 ` [PATCH 2/2] block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED Tejun Heo 2012-06-04 13:23 ` Jens Axboe
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