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authorAl Viro <viro@zeniv.linux.org.uk>2006-03-18 15:05:53 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2006-03-18 18:34:15 -0500
commit334e94de9bea353156abd6f2242d3cc4a24562b0 (patch)
treeff4a253e9e3bf487be03bf58727a7ea40a34ba87 /block/as-iosched.c
parente17a9489b4a686bb5e9615e1d375c67619cb99c5 (diff)
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[PATCH] deal with rmmod/put_io_context() races
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'block/as-iosched.c')
-rw-r--r--block/as-iosched.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index d2ee2af44b5..55a997fc4bb 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -182,6 +182,9 @@ struct as_rq {
static kmem_cache_t *arq_pool;
+static atomic_t ioc_count = ATOMIC_INIT(0);
+static struct completion *ioc_gone;
+
static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq);
static void as_antic_stop(struct as_data *ad);
@@ -193,11 +196,14 @@ static void as_antic_stop(struct as_data *ad);
static void free_as_io_context(struct as_io_context *aic)
{
kfree(aic);
+ if (atomic_dec_and_test(&ioc_count) && ioc_gone)
+ complete(ioc_gone);
}
static void as_trim(struct io_context *ioc)
{
- kfree(ioc->aic);
+ if (ioc->aic)
+ free_as_io_context(ioc->aic);
ioc->aic = NULL;
}
@@ -226,6 +232,7 @@ static struct as_io_context *alloc_as_io_context(void)
ret->seek_total = 0;
ret->seek_samples = 0;
ret->seek_mean = 0;
+ atomic_inc(&ioc_count);
}
return ret;
@@ -1900,7 +1907,13 @@ static int __init as_init(void)
static void __exit as_exit(void)
{
+ DECLARE_COMPLETION(all_gone);
elv_unregister(&iosched_as);
+ ioc_gone = &all_gone;
+ barrier();
+ if (atomic_read(&ioc_count))
+ complete(ioc_gone);
+ synchronize_rcu();
kmem_cache_destroy(arq_pool);
}