coredump: move mm->core_waiters into struct core_state
[linux-2.6.git] / fs / exec.c
index 7173456..50de3aa 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -722,12 +722,10 @@ static int exec_mmap(struct mm_struct *mm)
                 * Make sure that if there is a core dump in progress
                 * for the old mm, we get out and die instead of going
                 * through with the exec.  We must hold mmap_sem around
-                * checking core_waiters and changing tsk->mm.  The
-                * core-inducing thread will increment core_waiters for
-                * each thread whose ->mm == old_mm.
+                * checking core_state and changing tsk->mm.
                 */
                down_read(&old_mm->mmap_sem);
-               if (unlikely(old_mm->core_waiters)) {
+               if (unlikely(old_mm->core_state)) {
                        up_read(&old_mm->mmap_sem);
                        return -EINTR;
                }
@@ -1514,7 +1512,7 @@ static void zap_process(struct task_struct *start)
        t = start;
        do {
                if (t != current && t->mm) {
-                       t->mm->core_waiters++;
+                       t->mm->core_state->nr_threads++;
                        sigaddset(&t->pending.signal, SIGKILL);
                        signal_wake_up(t, 1);
                }
@@ -1538,11 +1536,11 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
        if (err)
                return err;
 
-       if (atomic_read(&mm->mm_users) == mm->core_waiters + 1)
+       if (atomic_read(&mm->mm_users) == mm->core_state->nr_threads + 1)
                goto done;
        /*
         * We should find and kill all tasks which use this mm, and we should
-        * count them correctly into mm->core_waiters. We don't take tasklist
+        * count them correctly into ->nr_threads. We don't take tasklist
         * lock, but this is safe wrt:
         *
         * fork:
@@ -1590,7 +1588,7 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
        }
        rcu_read_unlock();
 done:
-       return mm->core_waiters;
+       return mm->core_state->nr_threads;
 }
 
 static int coredump_wait(int exit_code)
@@ -1603,9 +1601,12 @@ static int coredump_wait(int exit_code)
 
        init_completion(&mm->core_done);
        init_completion(&core_state.startup);
+       core_state.nr_threads = 0;
        mm->core_state = &core_state;
 
        core_waiters = zap_threads(tsk, mm, exit_code);
+       if (core_waiters < 0)
+               mm->core_state = NULL;
        up_write(&mm->mmap_sem);
 
        if (unlikely(core_waiters < 0))
@@ -1623,8 +1624,8 @@ static int coredump_wait(int exit_code)
 
        if (core_waiters)
                wait_for_completion(&core_state.startup);
+       mm->core_state = NULL;
 fail:
-       BUG_ON(mm->core_waiters);
        return core_waiters;
 }
 
@@ -1702,7 +1703,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        /*
         * If another thread got here first, or we are not dumpable, bail out.
         */
-       if (mm->core_waiters || !get_dumpable(mm)) {
+       if (mm->core_state || !get_dumpable(mm)) {
                up_write(&mm->mmap_sem);
                goto fail;
        }