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| author | Jan Kara <jack@suse.cz> | 2017-04-11 11:29:01 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-04-11 08:09:14 -0600 |
| commit | 3f19cd23f3a9420fe7bd98ad41d05e45fa6d4d47 (patch) | |
| tree | 1070c884072bcc98912373ca6953c2010451b1a5 /block/blk-wbt.c | |
| parent | f5c0b0910ac4c1bc93474d7593cc73622fdfc822 (diff) | |
| download | linux-0-day-3f19cd23f3a9420fe7bd98ad41d05e45fa6d4d47.tar.gz linux-0-day-3f19cd23f3a9420fe7bd98ad41d05e45fa6d4d47.tar.xz | |
block: Fix list corruption of blk stats callback list
When CFQ calls wbt_disable_default(), it will call
blk_stat_remove_callback() to stop gathering IO statistics for the
purposes of writeback throttling. Later, when request_queue is
unregistered, wbt_exit() will call blk_stat_remove_callback() again
which will try to delete callback from the list again and possibly cause
list corruption.
Fix the problem by making wbt_disable_default() called wbt_exit() which
is properly guarded against being called multiple times.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-wbt.c')
| -rw-r--r-- | block/blk-wbt.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index ffa80e11cf142..b3b79149d3a0c 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -653,19 +653,15 @@ void wbt_set_write_cache(struct rq_wb *rwb, bool write_cache_on) rwb->wc = write_cache_on; } - /* - * Disable wbt, if enabled by default. Only called from CFQ, if we have - * cgroups enabled +/* + * Disable wbt, if enabled by default. Only called from CFQ. */ void wbt_disable_default(struct request_queue *q) { struct rq_wb *rwb = q->rq_wb; - if (rwb && rwb->enable_state == WBT_STATE_ON_DEFAULT) { - blk_stat_remove_callback(q, rwb->cb); - rwb->win_nsec = rwb->min_lat_nsec = 0; - wbt_update_limits(rwb); - } + if (rwb && rwb->enable_state == WBT_STATE_ON_DEFAULT) + wbt_exit(q); } EXPORT_SYMBOL_GPL(wbt_disable_default); |