btrfs: sysfs: add UUID/debug/discard directory

Setup base sysfs directory for discard stats + tunables.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0626e55..7131704 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -930,6 +930,7 @@ struct btrfs_fs_info {
 
 #ifdef CONFIG_BTRFS_DEBUG
        struct kobject *debug_kobj;
+       struct kobject *discard_debug_kobj;
 #endif
 };
 

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 5a09c7a..0eec1a8 100644 (file)
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -339,6 +339,13 @@ static const struct attribute_group btrfs_static_feature_attr_group = {
 #ifdef CONFIG_BTRFS_DEBUG
 
 /*
+ * Discard statistics and tunables
+ */
+static const struct attribute *discard_debug_attrs[] = {
+       NULL,
+};
+
+/*
  * Runtime debugging exported via sysfs
  *
  * /sys/fs/btrfs/debug - applies to module or all filesystems
@@ -776,6 +783,12 @@ void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
                kobject_put(fs_info->space_info_kobj);
        }
 #ifdef CONFIG_BTRFS_DEBUG
+       if (fs_info->discard_debug_kobj) {
+               sysfs_remove_files(fs_info->discard_debug_kobj,
+                                  discard_debug_attrs);
+               kobject_del(fs_info->discard_debug_kobj);
+               kobject_put(fs_info->discard_debug_kobj);
+       }
        if (fs_info->debug_kobj) {
                sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
                kobject_del(fs_info->debug_kobj);
@@ -1127,6 +1140,19 @@ int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
        error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
        if (error)
                goto failure;
+
+       /* Discard directory */
+       fs_info->discard_debug_kobj = kobject_create_and_add("discard",
+                                                    fs_info->debug_kobj);
+       if (!fs_info->discard_debug_kobj) {
+               error = -ENOMEM;
+               goto failure;
+       }
+
+       error = sysfs_create_files(fs_info->discard_debug_kobj,
+                                  discard_debug_attrs);
+       if (error)
+               goto failure;
 #endif
 
        error = addrm_unknown_feature_attrs(fs_info, true);