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authorNadia Derbey <Nadia.Derbey@bull.net>2008-07-25 10:48:03 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 19:53:42 +0200
commit00c2bf85d8febfcfddde63822043462b026134ff (patch)
tree25dbdf6d713408da992eace1168c45244d13c2a7 /ipc/shm.c
parentipc: call idr_find() without locking in ipc_lock() (diff)
downloadlinux-00c2bf85d8febfcfddde63822043462b026134ff.tar.xz
linux-00c2bf85d8febfcfddde63822043462b026134ff.zip
ipc: get rid of ipc_lock_down()
Remove the ipc_lock_down() routines: they used to call idr_find() locklessly (given that the ipc ids lock was already held), so they are not needed anymore. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/shm.c')
-rw-r--r--ipc/shm.c21
1 files changed, 3 insertions, 18 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index a726aebce7d7..e77ec698cf40 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -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_struct *vma)
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();
@@ -932,7 +917,7 @@ 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 &&