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| author | Shaohua Li <shaohua.li@intel.com> | 2010-05-25 10:16:53 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2010-05-25 10:17:26 +0200 |
| commit | d02a2c077fb81f3224c770be62a318165b23b486 (patch) | |
| tree | 74696554d35fe81d52236d4059ef2af51d870d84 /block/cfq-iosched.c | |
| parent | b9598db3401282bb27b4aef77e3eee12015f7f29 (diff) | |
| download | lwn-d02a2c077fb81f3224c770be62a318165b23b486.tar.gz lwn-d02a2c077fb81f3224c770be62a318165b23b486.zip | |
cfq-iosched: fix an oops caused by slab leak
I got below oops when unloading cfq-iosched. Considering scenario:
queue A merge to B, C merge to D and B will be merged to D. Before B is merged
to D, we do split B. We should put B's reference for D.
[ 807.768536] =============================================================================
[ 807.768539] BUG cfq_queue: Objects remaining on kmem_cache_close()
[ 807.768541] -----------------------------------------------------------------------------
[ 807.768543]
[ 807.768546] INFO: Slab 0xffffea0003e6b4e0 objects=26 used=1 fp=0xffff88011d584fd8 flags=0x200000000004082
[ 807.768550] Pid: 5946, comm: rmmod Tainted: G W 2.6.34-07097-gf4b87de-dirty #724
[ 807.768552] Call Trace:
[ 807.768560] [<ffffffff81104e8d>] slab_err+0x8f/0x9d
[ 807.768564] [<ffffffff811059e1>] ? flush_cpu_slab+0x0/0x93
[ 807.768569] [<ffffffff8164be52>] ? add_preempt_count+0xe/0xca
[ 807.768572] [<ffffffff8164bd9c>] ? sub_preempt_count+0xe/0xb6
[ 807.768577] [<ffffffff81648871>] ? _raw_spin_unlock+0x15/0x30
[ 807.768580] [<ffffffff8164bd9c>] ? sub_preempt_count+0xe/0xb6
[ 807.768584] [<ffffffff811061bc>] list_slab_objects+0x9b/0x19f
[ 807.768588] [<ffffffff8164bf0a>] ? add_preempt_count+0xc6/0xca
[ 807.768591] [<ffffffff81109e27>] kmem_cache_destroy+0x13f/0x21d
[ 807.768597] [<ffffffffa000ff13>] cfq_slab_kill+0x1a/0x43 [cfq_iosched]
[ 807.768601] [<ffffffffa000ffcf>] cfq_exit+0x93/0x9e [cfq_iosched]
[ 807.768606] [<ffffffff810973a2>] sys_delete_module+0x1b1/0x219
[ 807.768612] [<ffffffff8102fb5b>] system_call_fastpath+0x16/0x1b
[ 807.768618] INFO: Object 0xffff88011d584618 @offset=1560
[ 807.768622] INFO: Allocated in cfq_get_queue+0x11e/0x274 [cfq_iosched] age=7173 cpu=1 pid=5496
[ 807.768626] =============================================================================
Cc: stable@kernel.org
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c72e5acc573d..5ff4f4850e71 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2560,15 +2560,10 @@ static void cfq_free_io_context(struct io_context *ioc) __call_for_each_cic(ioc, cic_free_func); } -static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) +static void cfq_put_cooperator(struct cfq_queue *cfqq) { struct cfq_queue *__cfqq, *next; - if (unlikely(cfqq == cfqd->active_queue)) { - __cfq_slice_expired(cfqd, cfqq, 0); - cfq_schedule_dispatch(cfqd); - } - /* * If this queue was scheduled to merge with another queue, be * sure to drop the reference taken on that queue (and others in @@ -2584,6 +2579,16 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) cfq_put_queue(__cfqq); __cfqq = next; } +} + +static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) +{ + if (unlikely(cfqq == cfqd->active_queue)) { + __cfq_slice_expired(cfqd, cfqq, 0); + cfq_schedule_dispatch(cfqd); + } + + cfq_put_cooperator(cfqq); cfq_put_queue(cfqq); } @@ -3536,6 +3541,9 @@ split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) } cic_set_cfqq(cic, NULL, 1); + + cfq_put_cooperator(cfqq); + cfq_put_queue(cfqq); return NULL; } |