[PATCH] Cleanup patch for process freezing

1. Establish a simple API for process freezing defined in linux/include/sched.h:

   frozen(process)		Check for frozen process
   freezing(process)		Check if a process is being frozen
   freeze(process)		Tell a process to freeze (go to refrigerator)
   thaw_process(process)	Restart process
   frozen_process(process)	Process is frozen now

2. Remove all references to PF_FREEZE and PF_FROZEN from all
   kernel sources except sched.h

3. Fix numerous locations where try_to_freeze is manually done by a driver

4. Remove the argument that is no longer necessary from two function calls.

5. Some whitespace cleanup

6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
   cleared before setting PF_FROZEN, recalc_sigpending does not check
   PF_FROZEN).

This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!

Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 6 insertions, 6 deletions

diff --git a/net/rxrpc/krxiod.c b/net/rxrpc/krxiod.c
index 2b537f425a17..dada34a77b21 100644
--- a/net/rxrpc/krxiod.c
+++ b/net/rxrpc/krxiod.c
@@ -138,7 +138,7 @@ static int rxrpc_krxiod(void *arg)
 
                 _debug("### End Work");
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/rxrpc/krxsecd.c b/net/rxrpc/krxsecd.c
index 6020c89d9228..1aadd026d354 100644
--- a/net/rxrpc/krxsecd.c
+++ b/net/rxrpc/krxsecd.c
@@ -107,7 +107,7 @@ static int rxrpc_krxsecd(void *arg)
 
                 _debug("### End Inbound Calls");
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/rxrpc/krxtimod.c b/net/rxrpc/krxtimod.c
index 249c2b0290bb..3ac81cdd1211 100644
--- a/net/rxrpc/krxtimod.c
+++ b/net/rxrpc/krxtimod.c
@@ -90,7 +90,7 @@ static int krxtimod(void *arg)
                         complete_and_exit(&krxtimod_dead, 0);
                 }
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 05907035bc96..56db8f13e6cb 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1185,8 +1185,8 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
         arg->page_len = (pages-2)*PAGE_SIZE;
         arg->len = (pages-1)*PAGE_SIZE;
         arg->tail[0].iov_len = 0;
-        
-        try_to_freeze(PF_FREEZE);
+
+        try_to_freeze();
         if (signalled())
                 return -EINTR;
 
@@ -1227,7 +1227,7 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
 
                 schedule_timeout(timeout);
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 spin_lock_bh(&serv->sv_lock);
                 remove_wait_queue(&rqstp->rq_wait, &wait);