idr: make idr_get_new* rcu-safe
Make the idr_get_new* routines rcu-safe.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Jim Houston <jim.houston@comcast.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
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 80ba06f..44ab3b2 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -6,6 +6,8 @@
* Modified by George Anzinger to reuse immediately and to use
* find bit instructions. Also removed _irq on spinlocks.
*
+ * Modified by Nadia Derbey to make it RCU safe.
+ *
* Small id to pointer translation service.
*
* It uses a radix tree like structure as a sparse array indexed
@@ -96,7 +98,7 @@
* @gfp_mask: memory allocation flags
*
* This function should be called prior to locking and calling the
- * following function. It preallocates enough memory to satisfy
+ * idr_get_new* functions. It preallocates enough memory to satisfy
* the worst possible allocation.
*
* If the system is REALLY out of memory this function returns 0,
@@ -170,7 +172,7 @@
new = get_from_free_list(idp);
if (!new)
return -1;
- p->ary[m] = new;
+ rcu_assign_pointer(p->ary[m], new);
p->count++;
}
pa[l--] = p;
@@ -226,7 +228,7 @@
__set_bit(0, &new->bitmap);
p = new;
}
- idp->top = p;
+ rcu_assign_pointer(idp->top, p);
idp->layers = layers;
v = sub_alloc(idp, &id, pa);
if (v == IDR_NEED_TO_GROW)
@@ -245,7 +247,8 @@
* Successfully found an empty slot. Install the user
* pointer and mark the slot full.
*/
- pa[0]->ary[id & IDR_MASK] = (struct idr_layer *)ptr;
+ rcu_assign_pointer(pa[0]->ary[id & IDR_MASK],
+ (struct idr_layer *)ptr);
pa[0]->count++;
idr_mark_full(pa, id);
}
@@ -710,7 +713,8 @@
return -EAGAIN;
memset(bitmap, 0, sizeof(struct ida_bitmap));
- pa[0]->ary[idr_id & IDR_MASK] = (void *)bitmap;
+ rcu_assign_pointer(pa[0]->ary[idr_id & IDR_MASK],
+ (void *)bitmap);
pa[0]->count++;
}