btrfs: factor sysfs code out of link_block_group
The part of link_block_group that just creates the sysfs object is
independent and can be factored out to a helper.
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 115499c..50cb9f9 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -4,6 +4,7 @@
*/
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
@@ -749,6 +750,51 @@ static void init_feature_attrs(void)
}
}
+/*
+ * Create a sysfs entry for a given block group type at path
+ * /sys/fs/btrfs/UUID/allocation/data/TYPE
+ */
+void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache)
+{
+ struct btrfs_fs_info *fs_info = cache->fs_info;
+ struct btrfs_space_info *space_info = cache->space_info;
+ struct raid_kobject *rkobj;
+ const int index = btrfs_bg_flags_to_raid_index(cache->flags);
+ unsigned int nofs_flag;
+ int ret;
+
+ /*
+ * Setup a NOFS context because kobject_add(), deep in its call chain,
+ * does GFP_KERNEL allocations, and we are often called in a context
+ * where if reclaim is triggered we can deadlock (we are either holding
+ * a transaction handle or some lock required for a transaction
+ * commit).
+ */
+ nofs_flag = memalloc_nofs_save();
+
+ rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+ if (!rkobj) {
+ memalloc_nofs_restore(nofs_flag);
+ btrfs_warn(cache->fs_info,
+ "couldn't alloc memory for raid level kobject");
+ return;
+ }
+
+ rkobj->flags = cache->flags;
+ kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
+ ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
+ btrfs_bg_type_to_raid_name(rkobj->flags));
+ memalloc_nofs_restore(nofs_flag);
+ if (ret) {
+ kobject_put(&rkobj->kobj);
+ btrfs_warn(fs_info,
+ "failed to add kobject for block cache, ignoring");
+ return;
+ }
+
+ space_info->block_group_kobjs[index] = &rkobj->kobj;
+}
+
/* when one_device is NULL, it removes all device links */
int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,