71 lines
2.3 KiB
Diff
71 lines
2.3 KiB
Diff
From 3a527bb7e00bb9650f28d273f56c872db03452c5 Mon Sep 17 00:00:00 2001
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From: Hannes Reinecke <hare@suse.de>
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Date: Wed, 28 Sep 2011 08:07:01 -0600
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Subject: [PATCH] block: Free queue resources at blk_release_queue()
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A kernel crash is observed when a mounted ext3/ext4 filesystem is
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physically removed. The problem is that blk_cleanup_queue() frees up
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some resources eg by calling elevator_exit(), which are not checked for
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in normal operation. So we should rather move these calls to the
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destructor function blk_release_queue() as at that point all remaining
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references are gone. However, in doing so we have to ensure that any
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externally supplied queue_lock is disconnected as the driver might free
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up the lock after the call of blk_cleanup_queue(),
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Signed-off-by: Hannes Reinecke <hare@suse.de>
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Signed-off-by: Jens Axboe <axboe@kernel.dk>
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---
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block/blk-core.c | 13 ++++++-------
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block/blk-sysfs.c | 5 +++++
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2 files changed, 11 insertions(+), 7 deletions(-)
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diff --git a/block/blk-core.c b/block/blk-core.c
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index 1d49e1c..847d04e 100644
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--- a/block/blk-core.c
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+++ b/block/blk-core.c
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@@ -348,9 +348,10 @@ void blk_put_queue(struct request_queue *q)
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EXPORT_SYMBOL(blk_put_queue);
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/*
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- * Note: If a driver supplied the queue lock, it should not zap that lock
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- * unexpectedly as some queue cleanup components like elevator_exit() and
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- * blk_throtl_exit() need queue lock.
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+ * Note: If a driver supplied the queue lock, it is disconnected
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+ * by this function. The actual state of the lock doesn't matter
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+ * here as the request_queue isn't accessible after this point
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+ * (QUEUE_FLAG_DEAD is set) and no other requests will be queued.
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*/
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void blk_cleanup_queue(struct request_queue *q)
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{
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@@ -367,10 +368,8 @@ void blk_cleanup_queue(struct request_queue *q)
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queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
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mutex_unlock(&q->sysfs_lock);
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- if (q->elevator)
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- elevator_exit(q->elevator);
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-
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- blk_throtl_exit(q);
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+ if (q->queue_lock != &q->__queue_lock)
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+ q->queue_lock = &q->__queue_lock;
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blk_put_queue(q);
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}
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diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
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index d935bd8..45c56d8 100644
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--- a/block/blk-sysfs.c
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+++ b/block/blk-sysfs.c
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@@ -472,6 +472,11 @@ static void blk_release_queue(struct kobject *kobj)
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blk_sync_queue(q);
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+ if (q->elevator)
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+ elevator_exit(q->elevator);
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+
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+ blk_throtl_exit(q);
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+
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if (rl->rq_pool)
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mempool_destroy(rl->rq_pool);
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--
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1.7.6
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