Merge branch 'next' into for-linus

Prepare first set of updates for 3.10 merge window.

1 files changed, 19 insertions, 23 deletions

diff --git a/ipc/util.c b/ipc/util.c
index 72fd0785ac94..464a8abd779f 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -122,6 +122,7 @@ void ipc_init_ids(struct ipc_ids *ids)
 
 	ids->in_use = 0;
 	ids->seq = 0;
+	ids->next_id = -1;
 	{
 		int seq_limit = INT_MAX/SEQ_MULTIPLIER;
 		if (seq_limit > USHRT_MAX)
@@ -251,7 +252,8 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 {
 	kuid_t euid;
 	kgid_t egid;
-	int id, err;
+	int id;
+	int next_id = ids->next_id;
 
 	if (size > IPCMNI)
 		size = IPCMNI;
@@ -259,16 +261,21 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	if (ids->in_use >= size)
 		return -ENOSPC;
 
+	idr_preload(GFP_KERNEL);
+
 	spin_lock_init(&new->lock);
 	new->deleted = 0;
 	rcu_read_lock();
 	spin_lock(&new->lock);
 
-	err = idr_get_new(&ids->ipcs_idr, new, &id);
-	if (err) {
+	id = idr_alloc(&ids->ipcs_idr, new,
+		       (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
+		       GFP_NOWAIT);
+	idr_preload_end();
+	if (id < 0) {
 		spin_unlock(&new->lock);
 		rcu_read_unlock();
-		return err;
+		return id;
 	}
 
 	ids->in_use++;
@@ -277,9 +284,14 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	new->cuid = new->uid = euid;
 	new->gid = new->cgid = egid;
 
-	new->seq = ids->seq++;
-	if(ids->seq > ids->seq_max)
-		ids->seq = 0;
+	if (next_id < 0) {
+		new->seq = ids->seq++;
+		if (ids->seq > ids->seq_max)
+			ids->seq = 0;
+	} else {
+		new->seq = ipcid_to_seqx(next_id);
+		ids->next_id = -1;
+	}
 
 	new->id = ipc_buildid(id, new->seq);
 	return id;
@@ -299,19 +311,10 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
 		struct ipc_ops *ops, struct ipc_params *params)
 {
 	int err;
-retry:
-	err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
-
-	if (!err)
-		return -ENOMEM;
 
 	down_write(&ids->rw_mutex);
 	err = ops->getnew(ns, params);
 	up_write(&ids->rw_mutex);
-
-	if (err == -EAGAIN)
-		goto retry;
-
 	return err;
 }
 
@@ -368,8 +371,6 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
 	struct kern_ipc_perm *ipcp;
 	int flg = params->flg;
 	int err;
-retry:
-	err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
 
 	/*
 	 * Take the lock as a writer since we are potentially going to add
@@ -381,8 +382,6 @@ retry:
 		/* key not used */
 		if (!(flg & IPC_CREAT))
 			err = -ENOENT;
-		else if (!err)
-			err = -ENOMEM;
 		else
 			err = ops->getnew(ns, params);
 	} else {
@@ -405,9 +404,6 @@ retry:
 	}
 	up_write(&ids->rw_mutex);
 
-	if (err == -EAGAIN)
-		goto retry;
-
 	return err;
 }