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>

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>
Nadia Derbey · Linus Torvalds
1 parent 944ca05c7b
Showing 1 changed file with 9 additions and 5 deletions Side-by-side Diff
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++;
 	}
...	...	@@ -6,6 +6,8 @@
6	6	* Modified by George Anzinger to reuse immediately and to use
7	7	* find bit instructions. Also removed _irq on spinlocks.
8	8	*
	9	+ * Modified by Nadia Derbey to make it RCU safe.
	10	+ *
9	11	* Small id to pointer translation service.
10	12	*
11	13	* It uses a radix tree like structure as a sparse array indexed
...	...	@@ -96,7 +98,7 @@
96	98	* @gfp_mask: memory allocation flags
97	99	*
98	100	* This function should be called prior to locking and calling the
99		- * following function. It preallocates enough memory to satisfy
	101	+ * idr_get_new* functions. It preallocates enough memory to satisfy
100	102	* the worst possible allocation.
101	103	*
102	104	* If the system is REALLY out of memory this function returns 0,
...	...	@@ -170,7 +172,7 @@
170	172	new = get_from_free_list(idp);
171	173	if (!new)
172	174	return -1;
173		- p->ary[m] = new;
	175	+ rcu_assign_pointer(p->ary[m], new);
174	176	p->count++;
175	177	}
176	178	pa[l--] = p;
...	...	@@ -226,7 +228,7 @@
226	228	__set_bit(0, &new->bitmap);
227	229	p = new;
228	230	}
229		- idp->top = p;
	231	+ rcu_assign_pointer(idp->top, p);
230	232	idp->layers = layers;
231	233	v = sub_alloc(idp, &id, pa);
232	234	if (v == IDR_NEED_TO_GROW)
...	...	@@ -245,7 +247,8 @@
245	247	* Successfully found an empty slot. Install the user
246	248	* pointer and mark the slot full.
247	249	*/
248		- pa[0]->ary[id & IDR_MASK] = (struct idr_layer *)ptr;
	250	+ rcu_assign_pointer(pa[0]->ary[id & IDR_MASK],
	251	+ (struct idr_layer *)ptr);
249	252	pa[0]->count++;
250	253	idr_mark_full(pa, id);
251	254	}
...	...	@@ -710,7 +713,8 @@
710	713	return -EAGAIN;
711	714
712	715	memset(bitmap, 0, sizeof(struct ida_bitmap));
713		- pa[0]->ary[idr_id & IDR_MASK] = (void *)bitmap;
	716	+ rcu_assign_pointer(pa[0]->ary[idr_id & IDR_MASK],
	717	+ (void *)bitmap);
714	718	pa[0]->count++;
715	719	}
716	720