UBUNTU: Ubuntu-4.15.0-96.97

[mirror_ubuntu-bionic-kernel.git] / block / blk-mq-debugfs.c

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index b56a4f35720d8a46e8a5daf3f2c63a51475308a3..ead271fb641e5ab37f46f571a6ad7d780aa4b131 100644 (file)
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -607,6 +607,14 @@ static int hctx_active_show(void *data, struct seq_file *m)
        return 0;
 }
 
+static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
+{
+       struct blk_mq_hw_ctx *hctx = data;
+
+       seq_printf(m, "%u\n", hctx->dispatch_busy);
+       return 0;
+}
+
 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
        __acquires(&ctx->lock)
 {
@@ -703,7 +711,11 @@ static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
        const struct blk_mq_debugfs_attr *attr = m->private;
        void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 
-       if (!attr->write)
+       /*
+        * Attributes that only implement .seq_ops are read-only and 'attr' is
+        * the same with 'data' in this case.
+        */
+       if (attr == data || !attr->write)
                return -EPERM;
 
        return attr->write(data, buf, count, ppos);
@@ -772,6 +784,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
        {"queued", 0600, hctx_queued_show, hctx_queued_write},
        {"run", 0600, hctx_run_show, hctx_run_write},
        {"active", 0400, hctx_active_show},
+       {"dispatch_busy", 0400, hctx_dispatch_busy_show},
        {},
 };