fault-inject: add ratelimit option

Current debug levels are not optimal.  Especially if one want to provoke
big numbers of faults(broken device simulator) then any verbose level will
produce giant numbers of identical logging messages.  Let's add ratelimit
parameter for that purpose.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 4 deletions

diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index d7d501ea856d..f1cdeb024d17 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -40,10 +40,16 @@ EXPORT_SYMBOL_GPL(setup_fault_attr);
 
 static void fail_dump(struct fault_attr *attr)
 {
-        if (attr->verbose > 0)
-                printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure\n");
-        if (attr->verbose > 1)
-                dump_stack();
+        if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) {
+                printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n"
+                       "name %pd, interval %lu, probability %lu, "
+                       "space %d, times %d\n", attr->dname,
+                       attr->probability, attr->interval,
+                       atomic_read(&attr->space),
+                       atomic_read(&attr->times));
+                if (attr->verbose > 1)
+                        dump_stack();
+        }
 }
 
 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
@@ -202,6 +208,12 @@ struct dentry *fault_create_debugfs_attr(const char *name,
                 goto fail;
         if (!debugfs_create_ul("verbose", mode, dir, &attr->verbose))
                 goto fail;
+        if (!debugfs_create_u32("verbose_ratelimit_interval_ms", mode, dir,
+                                &attr->ratelimit_state.interval))
+                goto fail;
+        if (!debugfs_create_u32("verbose_ratelimit_burst", mode, dir,
+                                &attr->ratelimit_state.burst))
+                goto fail;
         if (!debugfs_create_bool("task-filter", mode, dir, &attr->task_filter))
                 goto fail;
 
@@ -222,6 +234,7 @@ struct dentry *fault_create_debugfs_attr(const char *name,
 
 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
 
+        attr->dname = dget(dir);
         return dir;
 fail:
         debugfs_remove_recursive(dir);