1 files changed, 33 insertions, 63 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 73f4d53c02f3..322e2816f2fb 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -106,8 +106,14 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr)
         if (layer_idr)
                 return get_from_free_list(layer_idr);
 
-        /* try to allocate directly from kmem_cache */
-        new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
+        /*
+         * Try to allocate directly from kmem_cache.  We want to try this
+         * before preload buffer; otherwise, non-preloading idr_alloc()
+         * users will end up taking advantage of preloading ones.  As the
+         * following is allowed to fail for preloaded cases, suppress
+         * warning this time.
+         */
+        new = kmem_cache_zalloc(idr_layer_cache, gfp_mask | __GFP_NOWARN);
         if (new)
                 return new;
 
@@ -115,18 +121,24 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr)
          * Try to fetch one from the per-cpu preload buffer if in process
          * context.  See idr_preload() for details.
          */
-        if (in_interrupt())
-                return NULL;
-
-        preempt_disable();
-        new = __this_cpu_read(idr_preload_head);
-        if (new) {
-                __this_cpu_write(idr_preload_head, new->ary[0]);
-                __this_cpu_dec(idr_preload_cnt);
-                new->ary[0] = NULL;
+        if (!in_interrupt()) {
+                preempt_disable();
+                new = __this_cpu_read(idr_preload_head);
+                if (new) {
+                        __this_cpu_write(idr_preload_head, new->ary[0]);
+                        __this_cpu_dec(idr_preload_cnt);
+                        new->ary[0] = NULL;
+                }
+                preempt_enable();
+                if (new)
+                        return new;
         }
-        preempt_enable();
-        return new;
+
+        /*
+         * Both failed.  Try kmem_cache again w/o adding __GFP_NOWARN so
+         * that memory allocation failure warning is printed as intended.
+         */
+        return kmem_cache_zalloc(idr_layer_cache, gfp_mask);
 }
 
 static void idr_layer_rcu_free(struct rcu_head *head)
@@ -184,20 +196,7 @@ static void idr_mark_full(struct idr_layer **pa, int id)
         }
 }
 
-/**
- * idr_pre_get - reserve resources for idr allocation
- * @idp:        idr handle
- * @gfp_mask:   memory allocation flags
- *
- * 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.
- */
-int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
+int __idr_pre_get(struct idr *idp, gfp_t gfp_mask)
 {
         while (idp->id_free_cnt < MAX_IDR_FREE) {
                 struct idr_layer *new;
@@ -208,13 +207,12 @@ int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
         }
         return 1;
 }
-EXPORT_SYMBOL(idr_pre_get);
+EXPORT_SYMBOL(__idr_pre_get);
 
 /**
  * sub_alloc - try to allocate an id without growing the tree depth
  * @idp: idr handle
  * @starting_id: id to start search at
- * @id: pointer to the allocated handle
  * @pa: idr_layer[MAX_IDR_LEVEL] used as backtrack buffer
  * @gfp_mask: allocation mask for idr_layer_alloc()
  * @layer_idr: optional idr passed to idr_layer_alloc()
@@ -376,25 +374,7 @@ static void idr_fill_slot(struct idr *idr, void *ptr, int id,
         idr_mark_full(pa, 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
- * @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 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
- */
-int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
+int __idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
 {
         struct idr_layer *pa[MAX_IDR_LEVEL + 1];
         int rv;
@@ -407,7 +387,7 @@ int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
         *id = rv;
         return 0;
 }
-EXPORT_SYMBOL(idr_get_new_above);
+EXPORT_SYMBOL(__idr_get_new_above);
 
 /**
  * idr_preload - preload for idr_alloc()
@@ -569,8 +549,7 @@ void idr_remove(struct idr *idp, int id)
         struct idr_layer *p;
         struct idr_layer *to_free;
 
-        /* see comment in idr_find_slowpath() */
-        if (WARN_ON_ONCE(id < 0))
+        if (id < 0)
                 return;
 
         sub_remove(idp, (idp->layers - 1) * IDR_BITS, id);
@@ -667,15 +646,7 @@ void *idr_find_slowpath(struct idr *idp, int id)
         int n;
         struct idr_layer *p;
 
-        /*
-         * If @id is negative, idr_find() used to ignore the sign bit and
-         * performed lookup with the rest of bits, which is weird and can
-         * lead to very obscure bugs.  We're now returning NULL for all
-         * negative IDs but just in case somebody was depending on the sign
-         * bit being ignored, let's trigger WARN_ON_ONCE() so that they can
-         * be detected and fixed.  WARN_ON_ONCE() can later be removed.
-         */
-        if (WARN_ON_ONCE(id < 0))
+        if (id < 0)
                 return NULL;
 
         p = rcu_dereference_raw(idp->top);
@@ -824,8 +795,7 @@ void *idr_replace(struct idr *idp, void *ptr, int id)
         int n;
         struct idr_layer *p, *old_p;
 
-        /* see comment in idr_find_slowpath() */
-        if (WARN_ON_ONCE(id < 0))
+        if (id < 0)
                 return ERR_PTR(-EINVAL);
 
         p = idp->top;
@@ -918,7 +888,7 @@ static void free_bitmap(struct ida *ida, struct ida_bitmap *bitmap)
 int ida_pre_get(struct ida *ida, gfp_t gfp_mask)
 {
         /* allocate idr_layers */
-        if (!idr_pre_get(&ida->idr, gfp_mask))
+        if (!__idr_pre_get(&ida->idr, gfp_mask))
                 return 0;
 
         /* allocate free_bitmap */