Commit c460b662 authored by Rik van Riel's avatar Rik van Riel Committed by Linus Torvalds

ipc,sem: open code and rename sem_lock

Rename sem_lock() to sem_obtain_lock(), so we can introduce a sem_lock()
later that only locks the sem_array and does nothing else.

Open code the locking from ipc_lock() in sem_obtain_lock() so we can
introduce finer grained locking for the sem_array in the next patch.

[ propagate the ipc_obtain_object() errno out of sem_obtain_lock()]
Signed-off-by: default avatarRik van Riel <>
Acked-by: default avatarDavidlohr Bueso <>
Cc: Chegu Vinod <>
Cc: Emmanuel Benisty <>
Cc: Jason Low <>
Cc: Michel Lespinasse <>
Cc: Peter Hurley <>
Cc: Stanislav Kinsbursky <>
Tested-by: default avatarSedat Dilek <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 16df3674
......@@ -194,14 +194,31 @@ void __init sem_init (void)
* sem_lock_(check_) routines are called in the paths where the rw_mutex
* is not held.
static inline struct sem_array *sem_lock(struct ipc_namespace *ns, int id)
static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns, int id)
struct kern_ipc_perm *ipcp = ipc_lock(&sem_ids(ns), id);
struct kern_ipc_perm *ipcp;
struct sem_array *sma;
if (IS_ERR(ipcp))
return (struct sem_array *)ipcp;
ipcp = ipc_obtain_object(&sem_ids(ns), id);
if (IS_ERR(ipcp)) {
sma = ERR_CAST(ipcp);
goto err;
return container_of(ipcp, struct sem_array, sem_perm);
/* ipc_rmid() may have already freed the ID while sem_lock
* was spinning: verify that the structure is still valid
if (!ipcp->deleted)
return container_of(ipcp, struct sem_array, sem_perm);
return sma;
static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
......@@ -1593,7 +1610,7 @@ sleep_again:
goto out_free;
sma = sem_lock(ns, semid);
sma = sem_obtain_lock(ns, semid);
* Wait until it's guaranteed that no wakeup_sem_queue_do() is ongoing.
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