Merge branch 'akpm-incoming-1'

[~andy/linux] / lib / idr.c

diff --git a/lib/idr.c b/lib/idr.c
index c1a2069017614e6f95a7c2a892fcca1c9c2a7ff1..e35850d3004a28995d544b40f8c13f9d6c404f32 100644 (file)
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -110,9 +110,10 @@ static void idr_mark_full(struct idr_layer **pa, int id)
  * @idp:       idr handle
  * @gfp_mask:  memory allocation flags
  *
- * This function should be called prior to locking and calling the
- * idr_get_new* functions. It preallocates enough memory to satisfy
- * the worst possible allocation.
+ * This function should be called prior to calling the idr_get_new* functions.
+ * It preallocates enough memory to satisfy the worst possible allocation. The
+ * caller should pass in GFP_KERNEL if possible.  This of course requires that
+ * no spinning locks be held.
  *
  * If the system is REALLY out of memory this function returns 0,
  * otherwise 1.
@@ -284,15 +285,17 @@ static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id)
  * idr_get_new_above - allocate new idr entry above or equal to a start id
  * @idp: idr handle
  * @ptr: pointer you want associated with the id
- * @start_id: id to start search at
+ * @starting_id: id to start search at
  * @id: pointer to the allocated handle
  *
  * This is the allocate id function.  It should be called with any
  * required locks.
  *
- * If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call.  If the idr is full, it will
- * return -ENOSPC.
+ * If allocation from IDR's private freelist fails, idr_get_new_above() will
+ * return -EAGAIN.  The caller should retry the idr_pre_get() call to refill
+ * IDR's preallocation and then retry the idr_get_new_above() call.
+ *
+ * If the idr is full idr_get_new_above() will return -ENOSPC.
  *
  * @id returns a value in the range @starting_id ... 0x7fffffff
  */
@@ -318,12 +321,11 @@ EXPORT_SYMBOL(idr_get_new_above);
  * @ptr: pointer you want associated with the id
  * @id: pointer to the allocated handle
  *
- * This is the allocate id function.  It should be called with any
- * required locks.
+ * If allocation from IDR's private freelist fails, idr_get_new_above() will
+ * return -EAGAIN.  The caller should retry the idr_pre_get() call to refill
+ * IDR's preallocation and then retry the idr_get_new_above() call.
  *
- * If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call.  If the idr is full, it will
- * return -ENOSPC.
+ * If the idr is full idr_get_new_above() will return -ENOSPC.
  *
  * @id returns a value in the range 0 ... 0x7fffffff
  */
@@ -479,7 +481,7 @@ EXPORT_SYMBOL(idr_remove_all);
 
 /**
  * idr_destroy - release all cached layers within an idr tree
- * idp: idr handle
+ * @idp: idr handle
  */
 void idr_destroy(struct idr *idp)
 {
@@ -586,10 +588,11 @@ EXPORT_SYMBOL(idr_for_each);
 /**
  * idr_get_next - lookup next object of id to given id.
  * @idp: idr handle
- * @id:  pointer to lookup key
+ * @nextidp:  pointer to lookup key
  *
  * Returns pointer to registered object with id, which is next number to
- * given id.
+ * given id. After being looked up, *@nextidp will be updated for the next
+ * iteration.
  */
 
 void *idr_get_next(struct idr *idp, int *nextidp)
@@ -602,7 +605,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
        /* find first ent */
        n = idp->layers * IDR_BITS;
        max = 1 << n;
-       p = rcu_dereference(idp->top);
+       p = rcu_dereference_raw(idp->top);
        if (!p)
                return NULL;
 
@@ -610,7 +613,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
                while (n > 0 && p) {
                        n -= IDR_BITS;
                        *paa++ = p;
-                       p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+                       p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
                }
 
                if (p) {
@@ -758,7 +761,7 @@ EXPORT_SYMBOL(ida_pre_get);
 /**
  * ida_get_new_above - allocate new ID above or equal to a start id
  * @ida:       ida handle
- * @staring_id:        id to start search at
+ * @starting_id: id to start search at
  * @p_id:      pointer to the allocated handle
  *
  * Allocate new ID above or equal to @ida.  It should be called with
@@ -912,7 +915,7 @@ EXPORT_SYMBOL(ida_remove);
 
 /**
  * ida_destroy - release all cached layers within an ida tree
- * ida:                ida handle
+ * @ida:               ida handle
  */
 void ida_destroy(struct ida *ida)
 {