nbd: Fix debugfs error handling

Static checker complains about the implemented error handling. It is
indeed wrong. We don't care about the return values of created debugfs
files.

We only have to check the return values of created dirs for NULL
pointer. If we use a null pointer as parent directory for files, this
may lead to debugfs files in wrong places.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e4c5cc1079344110298f0becd938d91b27685924..d61a04155d99c33722af247a9030b9dc646017ac 100644 (file)
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -892,50 +892,23 @@ static const struct file_operations nbd_dbg_flags_ops = {
 static int nbd_dev_dbg_init(struct nbd_device *nbd)
 {
        struct dentry *dir;
-       struct dentry *f;
+
+       if (!nbd_dbg_dir)
+               return -EIO;
 
        dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir);
-       if (IS_ERR_OR_NULL(dir)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s' (%ld)\n",
-                       nbd_name(nbd), PTR_ERR(dir));
-               return PTR_ERR(dir);
+       if (!dir) {
+               dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n",
+                       nbd_name(nbd));
+               return -EIO;
        }
        nbd->dbg_dir = dir;
 
-       f = debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
-       if (IS_ERR_OR_NULL(f)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks', %ld\n",
-                       PTR_ERR(f));
-               return PTR_ERR(f);
-       }
-
-       f = debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
-       if (IS_ERR_OR_NULL(f)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes', %ld\n",
-                       PTR_ERR(f));
-               return PTR_ERR(f);
-       }
-
-       f = debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
-       if (IS_ERR_OR_NULL(f)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout', %ld\n",
-                       PTR_ERR(f));
-               return PTR_ERR(f);
-       }
-
-       f = debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
-       if (IS_ERR_OR_NULL(f)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize', %ld\n",
-                       PTR_ERR(f));
-               return PTR_ERR(f);
-       }
-
-       f = debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops);
-       if (IS_ERR_OR_NULL(f)) {
-               dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags', %ld\n",
-                       PTR_ERR(f));
-               return PTR_ERR(f);
-       }
+       debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
+       debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
+       debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
+       debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
+       debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops);
 
        return 0;
 }
@@ -950,8 +923,8 @@ static int nbd_dbg_init(void)
        struct dentry *dbg_dir;
 
        dbg_dir = debugfs_create_dir("nbd", NULL);
-       if (IS_ERR(dbg_dir))
-               return PTR_ERR(dbg_dir);
+       if (!dbg_dir)
+               return -EIO;
 
        nbd_dbg_dir = dbg_dir;