[PATCH] ida: make ida_simple_get/put() IRQ safe

From: Tejun Heo
Date: Wed Oct 26 2011 - 16:33:18 EST


It's often convenient to be able to release resource from IRQ context.
Make ida_simple_*() use irqsave/restore spin ops so that they are IRQ
safe.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Acked-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
Andrew, can you please route this through mm?

Thank you.

lib/idr.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

Index: work/lib/idr.c
===================================================================
--- work.orig/lib/idr.c
+++ work/lib/idr.c
@@ -944,6 +944,7 @@ int ida_simple_get(struct ida *ida, unsi
{
int ret, id;
unsigned int max;
+ unsigned long flags;

BUG_ON((int)start < 0);
BUG_ON((int)end < 0);
@@ -959,7 +960,7 @@ again:
if (!ida_pre_get(ida, gfp_mask))
return -ENOMEM;

- spin_lock(&simple_ida_lock);
+ spin_lock_irqsave(&simple_ida_lock, flags);
ret = ida_get_new_above(ida, start, &id);
if (!ret) {
if (id > max) {
@@ -969,7 +970,7 @@ again:
ret = id;
}
}
- spin_unlock(&simple_ida_lock);
+ spin_unlock_irqrestore(&simple_ida_lock, flags);

if (unlikely(ret == -EAGAIN))
goto again;
@@ -985,10 +986,12 @@ EXPORT_SYMBOL(ida_simple_get);
*/
void ida_simple_remove(struct ida *ida, unsigned int id)
{
+ unsigned long flags;
+
BUG_ON((int)id < 0);
- spin_lock(&simple_ida_lock);
+ spin_lock_irqsave(&simple_ida_lock, flags);
ida_remove(ida, id);
- spin_unlock(&simple_ida_lock);
+ spin_unlock_irqrestore(&simple_ida_lock, flags);
}
EXPORT_SYMBOL(ida_simple_remove);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/