[PATCH 10/10]
With the previous patch ipc_lock() becomes lockless.
So there is no need anymore for ipc_lock_down()-like routines.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
---
ipc/shm.c | 21 +++------------------
ipc/util.c | 52 +---------------------------------------------------
ipc/util.h | 6 ------
3 files changed, 4 insertions(+), 75 deletions(-)
Index: linux-2.6.25-mm1/ipc/util.c
===================================================================
--- linux-2.6.25-mm1.orig/ipc/util.c 2008-04-29 14:53:14.000000000 +0200
+++ linux-2.6.25-mm1/ipc/util.c 2008-04-29 14:59:06.000000000 +0200
@@ -716,56 +716,6 @@ struct kern_ipc_perm *ipc_lock(struct ip
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 ridr 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. ridr 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 = ridr_find(&ids->ipcs_ridr, 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;
@@ -837,7 +787,7 @@ struct kern_ipc_perm *ipcctl_pre_down(st
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;
Index: linux-2.6.25-mm1/ipc/util.h
===================================================================
--- linux-2.6.25-mm1.orig/ipc/util.h 2008-04-25 15:29:13.000000000 +0200
+++ linux-2.6.25-mm1/ipc/util.h 2008-04-29 14:59:49.000000000 +0200
@@ -102,11 +102,6 @@ void* ipc_rcu_alloc(int size);
void ipc_rcu_getref(void *ptr);
void ipc_rcu_putref(void *ptr);
-/*
- * ipc_lock_down: called with rw_mutex held
- * ipc_lock: called without that lock held
- */
-struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
@@ -155,7 +150,6 @@ static inline void ipc_unlock(struct ker
rcu_read_unlock();
}
-struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id);
struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params);
Index: linux-2.6.25-mm1/ipc/shm.c
===================================================================
--- linux-2.6.25-mm1.orig/ipc/shm.c 2008-04-29 14:48:26.000000000 +0200
+++ linux-2.6.25-mm1/ipc/shm.c 2008-04-29 15:01:24.000000000 +0200
@@ -112,23 +112,8 @@ void __init shm_init (void)
}
/*
- * shm_lock_(check_)down routines are called in the paths where the rw_mutex
- * is held to protect access to the idr tree.
- */
-static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
- int id)
-{
- struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id);
-
- if (IS_ERR(ipcp))
- return (struct shmid_kernel *)ipcp;
-
- return container_of(ipcp, struct shmid_kernel, shm_perm);
-}
-
-/*
* shm_lock_(check_) routines are called in the paths where the rw_mutex
- * is not held.
+ * is not necessarily held.
*/
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
@@ -211,7 +196,7 @@ static void shm_close(struct vm_area_str
down_write(&shm_ids(ns).rw_mutex);
/* remove from the list of attaches of the shm segment */
- shp = shm_lock_down(ns, sfd->id);
+ shp = shm_lock(ns, sfd->id);
BUG_ON(IS_ERR(shp));
shp->shm_lprid = task_tgid_vnr(current);
shp->shm_dtim = get_seconds();
@@ -933,7 +918,7 @@ invalid:
out_nattch:
down_write(&shm_ids(ns).rw_mutex);
- shp = shm_lock_down(ns, shmid);
+ shp = shm_lock(ns, shmid);
BUG_ON(IS_ERR(shp));
shp->shm_nattch--;
if(shp->shm_nattch == 0 &&
--
--
