diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-04 19:13:40 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-05 02:19:39 +0200 |
| commit | 4091fd942e96af5a0b1dfa6aac5f44153ebf7cdb (patch) | |
| tree | 0455a439ad1a9884018286670e49c4e18cfaa359 | |
| parent | ipc: sem_putref() does not need the semaphore lock any more (diff) | |
| download | linux-4091fd942e96af5a0b1dfa6aac5f44153ebf7cdb.tar.xz linux-4091fd942e96af5a0b1dfa6aac5f44153ebf7cdb.zip | |
ipc: move the rcu_read_lock() from sem_lock_and_putref() into callers
This is another ipc semaphore locking cleanup, trying to make the
locking more straightforward. We move the rcu read locking into the
callers of sem_lock_and_putref(), which in general means that we now
mostly do the rcu_read_lock() and rcu_read_unlock() in the same
function.
Mostly. We still have the ipc_addid/newary/freeary mess, and things
like ipcctl_pre_down_nolock().
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | ipc/sem.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index 5cf7b4c093b3..8f5aa34f8d30 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -322,7 +322,6 @@ static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns static inline void sem_lock_and_putref(struct sem_array *sma) { - rcu_read_lock(); sem_lock(sma, NULL, -1); ipc_rcu_putref(sma); } @@ -1117,6 +1116,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, return -ENOMEM; } + rcu_read_lock(); sem_lock_and_putref(sma); if (sma->sem_perm.deleted) { sem_unlock(sma, -1); @@ -1166,6 +1166,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, goto out_free; } } + rcu_read_lock(); sem_lock_and_putref(sma); if (sma->sem_perm.deleted) { sem_unlock(sma, -1); @@ -1451,7 +1452,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) } /* step 3: Acquire the lock on semaphore array */ - /* This also does the rcu_read_lock() */ + rcu_read_lock(); sem_lock_and_putref(sma); if (sma->sem_perm.deleted) { sem_unlock(sma, -1); |