[PATCH] stop elv_unregister() from rogering other iosched's data, fix locking

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2006-03-18 13:21:20 -05:00
parent 25975f863b
commit e17a9489b4
4 changed files with 25 additions and 15 deletions

View File

@ -195,6 +195,12 @@ static void free_as_io_context(struct as_io_context *aic)
kfree(aic);
}
static void as_trim(struct io_context *ioc)
{
kfree(ioc->aic);
ioc->aic = NULL;
}
/* Called when the task exits */
static void exit_as_io_context(struct as_io_context *aic)
{
@ -1860,6 +1866,7 @@ static struct elevator_type iosched_as = {
.elevator_may_queue_fn = as_may_queue,
.elevator_init_fn = as_init_queue,
.elevator_exit_fn = as_exit_queue,
.trim = as_trim,
},
.elevator_ktype = &as_ktype,

View File

@ -1211,6 +1211,13 @@ static void cfq_free_io_context(struct cfq_io_context *cic)
kmem_cache_free(cfq_ioc_pool, cic);
}
static void cfq_trim(struct io_context *ioc)
{
ioc->set_ioprio = NULL;
if (ioc->cic)
cfq_free_io_context(ioc->cic);
}
/*
* Called with interrupts disabled
*/
@ -2472,6 +2479,7 @@ static struct elevator_type iosched_cfq = {
.elevator_may_queue_fn = cfq_may_queue,
.elevator_init_fn = cfq_init_queue,
.elevator_exit_fn = cfq_exit_queue,
.trim = cfq_trim,
},
.elevator_ktype = &cfq_ktype,
.elevator_name = "cfq",

View File

@ -675,21 +675,15 @@ void elv_unregister(struct elevator_type *e)
/*
* Iterate every thread in the process to remove the io contexts.
*/
read_lock(&tasklist_lock);
do_each_thread(g, p) {
struct io_context *ioc = p->io_context;
if (ioc && ioc->cic) {
ioc->cic->exit(ioc->cic);
ioc->cic->dtor(ioc->cic);
ioc->cic = NULL;
}
if (ioc && ioc->aic) {
ioc->aic->exit(ioc->aic);
ioc->aic->dtor(ioc->aic);
ioc->aic = NULL;
}
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
if (e->ops.trim) {
read_lock(&tasklist_lock);
do_each_thread(g, p) {
task_lock(p);
e->ops.trim(p->io_context);
task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
}
spin_lock_irq(&elv_list_lock);
list_del_init(&e->list);

View File

@ -48,6 +48,7 @@ struct elevator_ops
elevator_init_fn *elevator_init_fn;
elevator_exit_fn *elevator_exit_fn;
void (*trim)(struct io_context *);
};
#define ELV_NAME_MAX (16)