xnu-2782.20.48.tar.gz

[apple/xnu.git] / bsd / kern / kern_acct.c

diff --git a/bsd/kern/kern_acct.c b/bsd/kern/kern_acct.c
index 516de08dc0bc46896d9bd160375325c2654722e6..aec90c9e0d3b876f785a08bdc2c2de958dc2b63d 100644 (file)
--- a/bsd/kern/kern_acct.c
+++ b/bsd/kern/kern_acct.c
@@ -116,7 +116,7 @@
  */
 comp_t encode_comp_t(uint32_t, uint32_t);
 void   acctwatch(void *);
-void   acctwatch_funnel(void *);
+void   acct_init(void);
 
 /*
  * Accounting vnode pointer, and suspended accounting vnode pointer.  States
@@ -139,6 +139,21 @@ int        acctsuspend = 2;        /* stop accounting when < 2% free space left */
 int    acctresume = 4;         /* resume when free space risen to > 4% */
 int    acctchkfreq = 15;       /* frequency (in seconds) to check space */
 
+
+static lck_grp_t       *acct_subsys_lck_grp;
+static lck_mtx_t       *acct_subsys_mutex;
+
+#define ACCT_SUBSYS_LOCK() lck_mtx_lock(acct_subsys_mutex)
+#define ACCT_SUBSYS_UNLOCK() lck_mtx_unlock(acct_subsys_mutex)
+
+void
+acct_init(void)
+{
+       acct_subsys_lck_grp = lck_grp_alloc_init("acct", NULL);
+       acct_subsys_mutex = lck_mtx_alloc_init(acct_subsys_lck_grp, NULL);
+}
+
+
 /*
  * Accounting system call.  Written based on the specification and
  * previous implementation done by Mark Tinguely.
@@ -191,21 +206,26 @@ acct(proc_t p, struct acct_args *uap, __unused int *retval)
         * If accounting was previously enabled, kill the old space-watcher,
         * close the file, and (if no new file was specified, leave).
         */
+       ACCT_SUBSYS_LOCK();
        if (acctp != NULLVP || suspend_acctp != NULLVP) {
-               untimeout(acctwatch_funnel, NULL);
+               untimeout(acctwatch, NULL);
                error = vn_close((acctp != NULLVP ? acctp : suspend_acctp),
                                FWRITE, vfs_context_current());
 
                acctp = suspend_acctp = NULLVP;
        }
-       if (uap->path == USER_ADDR_NULL)
+       if (uap->path == USER_ADDR_NULL) {
+               ACCT_SUBSYS_UNLOCK();
                return (error);
+       }
 
        /*
         * Save the new accounting file vnode, and schedule the new
         * free space watcher.
         */
        acctp = nd.ni_vp;
+       ACCT_SUBSYS_UNLOCK();
+
        acctwatch(NULL);
        return (error);
 }
@@ -230,9 +250,12 @@ acct_process(proc_t p)
        struct  tty *tp;
 
        /* If accounting isn't enabled, don't bother */
+       ACCT_SUBSYS_LOCK();
        vp = acctp;
-       if (vp == NULLVP)
+       if (vp == NULLVP) {
+               ACCT_SUBSYS_UNLOCK();
                return (0);
+       }
 
        /*
         * Get process accounting information.
@@ -301,6 +324,8 @@ acct_process(proc_t p)
        }
 
        kauth_cred_unref(&safecred);
+       ACCT_SUBSYS_UNLOCK();
+
        return (error);
 }
 
@@ -342,16 +367,6 @@ encode_comp_t(uint32_t s, uint32_t us)
        return (exp);
 }
 
-/* XXX The acctwatch() thread need to be protected by a mutex instead. */
-void
-acctwatch_funnel(void *a)
-{
-        thread_funnel_set(kernel_flock, TRUE);
-       acctwatch(a);
-        thread_funnel_set(kernel_flock, FALSE);
-}
-
-
 /*
  * Periodically check the file system to see if accounting
  * should be turned on or off.  Beware the case where the vnode
@@ -369,6 +384,7 @@ acctwatch(__unused void *a)
        VFSATTR_WANTED(&va, f_blocks);
        VFSATTR_WANTED(&va, f_bavail);
 
+       ACCT_SUBSYS_LOCK();
        if (suspend_acctp != NULLVP) {
                /*
                 * Resuming accounting when accounting is suspended, and the
@@ -378,6 +394,7 @@ acctwatch(__unused void *a)
                if (suspend_acctp->v_type == VBAD) {
                        (void) vn_close(suspend_acctp, FWRITE, vfs_context_kernel());
                        suspend_acctp = NULLVP;
+                       ACCT_SUBSYS_UNLOCK();
                        return;
                }
                (void)vfs_getattr(suspend_acctp->v_mount, &va, ctx);
@@ -395,6 +412,7 @@ acctwatch(__unused void *a)
                if (acctp->v_type == VBAD) {
                        (void) vn_close(acctp, FWRITE, vfs_context_kernel());
                        acctp = NULLVP;
+                       ACCT_SUBSYS_UNLOCK();
                        return;
                }
                (void)vfs_getattr(acctp->v_mount, &va, ctx);
@@ -404,8 +422,10 @@ acctwatch(__unused void *a)
                        log(LOG_NOTICE, "Accounting suspended\n");
                }
        } else {
+               ACCT_SUBSYS_UNLOCK();
                return;
-        }
-        
-       timeout(acctwatch_funnel, NULL, acctchkfreq * hz);
+       }
+       ACCT_SUBSYS_UNLOCK();
+    
+       timeout(acctwatch, NULL, acctchkfreq * hz);
 }