blk-mq-debug: Introduce debugfs_create_files()

Replace the two debugfs_create_file() loops by a call to the new
debugfs_create_files() function. Add an empty element at the end
of the two attribute arrays such that the array size does not have
to be passed to debugfs_create_files().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 54b2f48..1077008 100644 (file)
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -652,6 +652,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
        {"queued", 0600, &hctx_queued_fops},
        {"run", 0600, &hctx_run_fops},
        {"active", 0400, &hctx_active_fops},
+       {},
 };
 
 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
@@ -659,6 +660,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
        {"dispatched", 0600, &ctx_dispatched_fops},
        {"merged", 0600, &ctx_merged_fops},
        {"completed", 0600, &ctx_completed_fops},
+       {},
 };
 
 int blk_mq_debugfs_register(struct request_queue *q, const char *name)
@@ -687,27 +689,31 @@ void blk_mq_debugfs_unregister(struct request_queue *q)
        q->debugfs_dir = NULL;
 }
 
+static bool debugfs_create_files(struct dentry *parent, void *data,
+                               const struct blk_mq_debugfs_attr *attr)
+{
+       for (; attr->name; attr++) {
+               if (!debugfs_create_file(attr->name, attr->mode, parent,
+                                        data, attr->fops))
+                       return false;
+       }
+       return true;
+}
+
 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
                                       struct blk_mq_ctx *ctx,
                                       struct dentry *hctx_dir)
 {
        struct dentry *ctx_dir;
        char name[20];
-       int i;
 
        snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
        ctx_dir = debugfs_create_dir(name, hctx_dir);
        if (!ctx_dir)
                return -ENOMEM;
 
-       for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) {
-               const struct blk_mq_debugfs_attr *attr;
-
-               attr = &blk_mq_debugfs_ctx_attrs[i];
-               if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx,
-                                        attr->fops))
-                       return -ENOMEM;
-       }
+       if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
+               return -ENOMEM;
 
        return 0;
 }
@@ -725,14 +731,8 @@ static int blk_mq_debugfs_register_hctx(struct request_queue *q,
        if (!hctx_dir)
                return -ENOMEM;
 
-       for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) {
-               const struct blk_mq_debugfs_attr *attr;
-
-               attr = &blk_mq_debugfs_hctx_attrs[i];
-               if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx,
-                                        attr->fops))
-                       return -ENOMEM;
-       }
+       if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
+               return -ENOMEM;
 
        hctx_for_each_ctx(hctx, ctx, i) {
                if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))