NFSv4: Ensure that we set the verifier when revalidating delegated dentries

[safe/jmp/linux-2.6] / kernel / marker.c

diff --git a/kernel/marker.c b/kernel/marker.c
index 1abfb92..e9c6b2b 100644 (file)
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -62,7 +62,7 @@ struct marker_entry {
        int refcount;   /* Number of times armed. 0 if disarmed. */
        struct rcu_head rcu;
        void *oldptr;
-       unsigned char rcu_pending:1;
+       int rcu_pending;
        unsigned char ptype:1;
        char name[0];   /* Contains name'\0'format'\0' */
 };
@@ -103,11 +103,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
        char ptype;
 
        /*
-        * preempt_disable does two things : disabling preemption to make sure
-        * the teardown of the callbacks can be done correctly when they are in
-        * modules and they insure RCU read coherency.
+        * rcu_read_lock_sched does two things : disabling preemption to make
+        * sure the teardown of the callbacks can be done correctly when they
+        * are in modules and they insure RCU read coherency.
         */
-       preempt_disable();
+       rcu_read_lock_sched();
        ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
@@ -126,6 +126,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
                struct marker_probe_closure *multi;
                int i;
                /*
+                * Read mdata->ptype before mdata->multi.
+                */
+               smp_rmb();
+               multi = mdata->multi;
+               /*
                 * multi points to an array, therefore accessing the array
                 * depends on reading multi. However, even in this case,
                 * we must insure that the pointer is read _before_ the array
@@ -133,7 +138,6 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = mdata->multi;
                for (i = 0; multi[i].func; i++) {
                        va_start(args, call_private);
                        multi[i].func(multi[i].probe_private, call_private,
@@ -141,7 +145,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
                        va_end(args);
                }
        }
-       preempt_enable();
+       rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb);
 
@@ -158,7 +162,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
        va_list args;   /* not initialized */
        char ptype;
 
-       preempt_disable();
+       rcu_read_lock_sched();
        ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
@@ -175,6 +179,11 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
                struct marker_probe_closure *multi;
                int i;
                /*
+                * Read mdata->ptype before mdata->multi.
+                */
+               smp_rmb();
+               multi = mdata->multi;
+               /*
                 * multi points to an array, therefore accessing the array
                 * depends on reading multi. However, even in this case,
                 * we must insure that the pointer is read _before_ the array
@@ -182,12 +191,11 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = mdata->multi;
                for (i = 0; multi[i].func; i++)
                        multi[i].func(multi[i].probe_private, call_private,
                                mdata->format, &args);
        }
-       preempt_enable();
+       rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
 
@@ -441,7 +449,7 @@ static int remove_marker(const char *name)
        hlist_del(&e->hlist);
        /* Make sure the call_rcu has been executed */
        if (e->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        kfree(e);
        return 0;
 }
@@ -476,7 +484,7 @@ static int marker_set_format(struct marker_entry **entry, const char *format)
        hlist_del(&(*entry)->hlist);
        /* Make sure the call_rcu has been executed */
        if ((*entry)->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        kfree(*entry);
        *entry = e;
        trace_mark(core_marker_format, "name %s format %s",
@@ -552,7 +560,7 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
  * Disable a marker and its probe callback.
  * Note: only waiting an RCU period after setting elem->call to the empty
  * function insures that the original callback is not used anymore. This insured
- * by preempt_disable around the call site.
+ * by rcu_read_lock_sched around the call site.
  */
 static void disable_marker(struct marker *elem)
 {
@@ -645,17 +653,23 @@ int marker_probe_register(const char *name, const char *format,
        entry = get_marker(name);
        if (!entry) {
                entry = add_marker(name, format);
-               if (IS_ERR(entry)) {
+               if (IS_ERR(entry))
                        ret = PTR_ERR(entry);
-                       goto end;
-               }
+       } else if (format) {
+               if (!entry->format)
+                       ret = marker_set_format(&entry, format);
+               else if (strcmp(entry->format, format))
+                       ret = -EPERM;
        }
+       if (ret)
+               goto end;
+
        /*
         * If we detect that a call_rcu is pending for this marker,
         * make sure it's executed now.
         */
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_add_probe(entry, probe, probe_private);
        if (IS_ERR(old)) {
                ret = PTR_ERR(old);
@@ -666,14 +680,13 @@ int marker_probe_register(const char *name, const char *format,
        mutex_lock(&markers_mutex);
        entry = get_marker(name);
        WARN_ON(!entry);
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
 end:
        mutex_unlock(&markers_mutex);
        return ret;
@@ -704,7 +717,7 @@ int marker_probe_unregister(const char *name,
        if (!entry)
                goto end;
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_remove_probe(entry, probe, probe_private);
        mutex_unlock(&markers_mutex);
        marker_update_probes();         /* may update entry */
@@ -712,14 +725,13 @@ int marker_probe_unregister(const char *name,
        entry = get_marker(name);
        if (!entry)
                goto end;
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
        remove_marker(name);    /* Ignore busy error message */
        ret = 0;
 end:
@@ -786,21 +798,20 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
                goto end;
        }
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_remove_probe(entry, NULL, probe_private);
        mutex_unlock(&markers_mutex);
        marker_update_probes();         /* may update entry */
        mutex_lock(&markers_mutex);
        entry = get_marker_from_private_data(probe, probe_private);
        WARN_ON(!entry);
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
        remove_marker(entry->name);     /* Ignore busy error message */
 end:
        mutex_unlock(&markers_mutex);