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ipc: rename ids->rw_mutex

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Since in some situations the lock can be shared for readers, we shouldn't
be calling it a mutex, rename it to rwsem.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Davidlohr Bueso
2013-09-11 14:26:24 -07:00
committed by Linus Torvalds
parent c2c737a046
commit d9a605e40b
7 changed files with 69 additions and 69 deletions
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20
ipc/msg.c
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@@ -172,7 +172,7 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
* @ns: namespace
* @params: ptr to the structure that contains the key and msgflg
*
* Called with msg_ids.rw_mutex held (writer)
* Called with msg_ids.rwsem held (writer)
*/
static int newque(struct ipc_namespace *ns, struct ipc_params *params)
{
@@ -259,8 +259,8 @@ static void expunge_all(struct msg_queue *msq, int res)
* removes the message queue from message queue ID IDR, and cleans up all the
* messages associated with this queue.
*
* msg_ids.rw_mutex (writer) and the spinlock for this message queue are held
* before freeque() is called. msg_ids.rw_mutex remains locked on exit.
* msg_ids.rwsem (writer) and the spinlock for this message queue are held
* before freeque() is called. msg_ids.rwsem remains locked on exit.
*/
static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
@@ -282,7 +282,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
}
/*
* Called with msg_ids.rw_mutex and ipcp locked.
* Called with msg_ids.rwsem and ipcp locked.
*/
static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
{
@@ -386,9 +386,9 @@ copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
}
/*
* This function handles some msgctl commands which require the rw_mutex
* This function handles some msgctl commands which require the rwsem
* to be held in write mode.
* NOTE: no locks must be held, the rw_mutex is taken inside this function.
* NOTE: no locks must be held, the rwsem is taken inside this function.
*/
static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
struct msqid_ds __user *buf, int version)
@@ -403,7 +403,7 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
return -EFAULT;
}
down_write(&msg_ids(ns).rw_mutex);
down_write(&msg_ids(ns).rwsem);
rcu_read_lock();
ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
@@ -459,7 +459,7 @@ out_unlock0:
out_unlock1:
rcu_read_unlock();
out_up:
up_write(&msg_ids(ns).rw_mutex);
up_write(&msg_ids(ns).rwsem);
return err;
}
@@ -494,7 +494,7 @@ static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
msginfo.msgmnb = ns->msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
msginfo.msgseg = MSGSEG;
down_read(&msg_ids(ns).rw_mutex);
down_read(&msg_ids(ns).rwsem);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids(ns).in_use;
msginfo.msgmap = atomic_read(&ns->msg_hdrs);
@@ -505,7 +505,7 @@ static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
msginfo.msgtql = MSGTQL;
}
max_id = ipc_get_maxid(&msg_ids(ns));
up_read(&msg_ids(ns).rw_mutex);
up_read(&msg_ids(ns).rwsem);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;