From 2955b47d2c1983998a8c5915cb96884e67f7cb53 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 9 Jul 2012 19:33:25 -0700 Subject: [SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams Acked-by: Arjan van de Ven Acked-by: Mark Brown Tested-by: Eldad Zack Signed-off-by: James Bottomley --- include/linux/async.h | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) (limited to 'include/linux/async.h') diff --git a/include/linux/async.h b/include/linux/async.h index 68a9530196f2..364e7ff16c08 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -9,19 +9,46 @@ * as published by the Free Software Foundation; version 2 * of the License. */ +#ifndef __ASYNC_H__ +#define __ASYNC_H__ #include #include typedef u64 async_cookie_t; typedef void (async_func_ptr) (void *data, async_cookie_t cookie); +struct async_domain { + struct list_head node; + struct list_head domain; + int count; + unsigned registered:1; +}; + +/* + * domain participates in global async_synchronize_full + */ +#define ASYNC_DOMAIN(_name) \ + struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \ + .domain = LIST_HEAD_INIT(_name.domain), \ + .count = 0, \ + .registered = 1 } + +/* + * domain is free to go out of scope as soon as all pending work is + * complete, this domain does not participate in async_synchronize_full + */ +#define ASYNC_DOMAIN_EXCLUSIVE(_name) \ + struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \ + .domain = LIST_HEAD_INIT(_name.domain), \ + .count = 0, \ + .registered = 0 } extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data); extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data, - struct list_head *list); + struct async_domain *domain); extern void async_synchronize_full(void); -extern void async_synchronize_full_domain(struct list_head *list); +extern void async_synchronize_full_domain(struct async_domain *domain); extern void async_synchronize_cookie(async_cookie_t cookie); extern void async_synchronize_cookie_domain(async_cookie_t cookie, - struct list_head *list); - + struct async_domain *domain); +#endif -- cgit From a4683487f90bfe3049686fc5c566bdc1ad03ace6 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 9 Jul 2012 19:33:30 -0700 Subject: [SCSI] async: make async_synchronize_full() flush all work regardless of domain In response to an async related regression James noted: "My theory is that this is an init problem: The assumption in a lot of our code is that async_synchronize_full() waits for everything ... even the domain specific async schedules, which isn't true." ...so make this assumption true. Each domain, including the default one, registers itself on a global domain list when work is scheduled. Once all entries complete it exits that list. Waiting for the list to be empty syncs all in-flight work across all domains. Domains can opt-out of global syncing if they are declared as exclusive ASYNC_DOMAIN_EXCLUSIVE(). All stack-based domains have been declared exclusive since the domain may go out of scope as soon as the last work item completes. Statically declared domains are mostly ok, but async_unregister_domain() is there to close any theoretical races with pending async_synchronize_full waiters at module removal time. Signed-off-by: Dan Williams Acked-by: Arjan van de Ven Reported-by: Meelis Roos Reported-by: Eldad Zack Tested-by: Eldad Zack Signed-off-by: James Bottomley --- include/linux/async.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/async.h') diff --git a/include/linux/async.h b/include/linux/async.h index 364e7ff16c08..7a24fe9b44b4 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -46,6 +46,7 @@ struct async_domain { extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data); extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data, struct async_domain *domain); +void async_unregister_domain(struct async_domain *domain); extern void async_synchronize_full(void); extern void async_synchronize_full_domain(struct async_domain *domain); extern void async_synchronize_cookie(async_cookie_t cookie); -- cgit