ida: make ida_simple_get/put() IRQ safe

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@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/idr.c b/lib/idr.c
index bbf211aea4ebed20f0190ccdf97c91baed7ad422..ed055b297c81c127dcbef79cb821f904936245c2 100644 (file)
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -944,6 +944,7 @@ int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
 {
        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);