From 334e94de9bea353156abd6f2242d3cc4a24562b0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 18 Mar 2006 15:05:53 -0500 Subject: [PATCH] deal with rmmod/put_io_context() races Signed-off-by: Al Viro --- block/as-iosched.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'block/as-iosched.c') 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); } -- cgit v1.2.3