sysvipc: fix the ipc structures initialization

[linux-2.6-omap-h63xx.git] / ipc / util.c

diff --git a/ipc/util.c b/ipc/util.c
index 3339177b336cae51c0b5a8085ad9a087891bb0b2..361fd1c96fcf31b92475882803dc927f281a8718 100644 (file)
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -266,9 +266,17 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
        if (ids->in_use >= size)
                return -ENOSPC;
 
+       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)
+       if (err) {
+               spin_unlock(&new->lock);
+               rcu_read_unlock();
                return err;
+       }
 
        ids->in_use++;
 
@@ -280,10 +288,6 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
                ids->seq = 0;
 
        new->id = ipc_buildid(id, new->seq);
-       spin_lock_init(&new->lock);
-       new->deleted = 0;
-       rcu_read_lock();
-       spin_lock(&new->lock);
        return id;
 }
 
@@ -688,10 +692,6 @@ void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
  * Look for an id in the ipc ids idr and lock the associated ipc object.
  *
  * The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is not already
- * held, i.e. idr tree not protected: it protects the idr tree in read mode
- * during the idr_find().
  */
 
 struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
@@ -699,18 +699,13 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
        struct kern_ipc_perm *out;
        int lid = ipcid_to_idx(id);
 
-       down_read(&ids->rw_mutex);
-
        rcu_read_lock();
        out = idr_find(&ids->ipcs_idr, lid);
        if (out == NULL) {
                rcu_read_unlock();
-               up_read(&ids->rw_mutex);
                return ERR_PTR(-EINVAL);
        }
 
-       up_read(&ids->rw_mutex);
-
        spin_lock(&out->lock);
        
        /* ipc_rmid() may have already freed the ID while ipc_lock
@@ -725,56 +720,6 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
        return out;
 }
 
-/**
- * ipc_lock_down - Lock an ipc structure with rw_sem held
- * @ids: IPC identifier set
- * @id: ipc id to look for
- *
- * Look for an id in the ipc ids idr and lock the associated ipc object.
- *
- * The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is already
- * held, i.e. idr tree protected.
- */
-
-struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *ids, int id)
-{
-       struct kern_ipc_perm *out;
-       int lid = ipcid_to_idx(id);
-
-       rcu_read_lock();
-       out = idr_find(&ids->ipcs_idr, lid);
-       if (out == NULL) {
-               rcu_read_unlock();
-               return ERR_PTR(-EINVAL);
-       }
-
-       spin_lock(&out->lock);
-
-       /*
-        * No need to verify that the structure is still valid since the
-        * rw_mutex is held.
-        */
-       return out;
-}
-
-struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id)
-{
-       struct kern_ipc_perm *out;
-
-       out = ipc_lock_down(ids, id);
-       if (IS_ERR(out))
-               return out;
-
-       if (ipc_checkid(out, id)) {
-               ipc_unlock(out);
-               return ERR_PTR(-EIDRM);
-       }
-
-       return out;
-}
-
 struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
 {
        struct kern_ipc_perm *out;
@@ -846,7 +791,7 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
        int err;
 
        down_write(&ids->rw_mutex);
-       ipcp = ipc_lock_check_down(ids, id);
+       ipcp = ipc_lock_check(ids, id);
        if (IS_ERR(ipcp)) {
                err = PTR_ERR(ipcp);
                goto out_up;