[v3,1/15] btrfs: add btrfs_sysfs_add_device helper

Commit Message

Anand Jain Sept. 3, 2020, 10:46 a.m. UTC

btrfs_sysfs_add_devices_dir() adds device link and devid kobject
(sysfs entries) for a device or all the devices in the btrfs_fs_devices.
In preparation to add these sysfs entries for the seed as well, add
a btrfs_sysfs_add_device() helper function and avoid code duplication.

Signed-off-by: Anand Jain <[e-mail]>
---
v3: Use device->fs_info instead of device->fs_devices->fs_info
    essentially both points to the same addr, but former is more
    efficient.
    Fix whitespace, which didn't appear red in the git diff earlier,
    strange.

 fs/btrfs/sysfs.c | 79 ++++++++++++++++++++++++++++++++----------------
 1 file changed, 53 insertions(+), 26 deletions(-)

Comments

Josef Bacik Sept. 3, 2020, 3:42 p.m. UTC | #1

On 9/3/20 6:46 AM, Anand Jain wrote:
> btrfs_sysfs_add_devices_dir() adds device link and devid kobject
> (sysfs entries) for a device or all the devices in the btrfs_fs_devices.
> In preparation to add these sysfs entries for the seed as well, add
> a btrfs_sysfs_add_device() helper function and avoid code duplication.
> 
> Signed-off-by: Anand Jain <[e-mail]>

Reviewed-by: Josef Bacik <[e-mail]>

Thanks,

Josef

Patch

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 190e59152be5..5cfa13957e2a 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1271,44 +1271,71 @@  static struct kobj_type devid_ktype = {
 	.release	= btrfs_release_devid_kobj,
 };
 
-int btrfs_sysfs_add_devices_dir(struct btrfs_fs_devices *fs_devices,
-				struct btrfs_device *one_device)
+static int btrfs_sysfs_add_device(struct btrfs_device *device)
 {
-	int error = 0;
-	struct btrfs_device *dev;
+	int ret;
 	unsigned int nofs_flag;
+	struct kobject *devices_kobj;
+	struct kobject *devinfo_kobj;
 
-	nofs_flag = memalloc_nofs_save();
-	list_for_each_entry(dev, &fs_devices->devices, dev_list) {
+	/*
+	 * make sure we use the fs_info::fs_devices to fetch the kobjects
+	 * even for the seed fs_devices
+	 */
+	devices_kobj = device->fs_info->fs_devices->devices_kobj;
+	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
+	ASSERT(devices_kobj);
+	ASSERT(devinfo_kobj);
 
-		if (one_device && one_device != dev)
-			continue;
+	nofs_flag = memalloc_nofs_save();
 
-		if (dev->bdev) {
-			struct hd_struct *disk;
-			struct kobject *disk_kobj;
+	if (device->bdev) {
+		struct hd_struct *disk;
+		struct kobject *disk_kobj;
 
-			disk = dev->bdev->bd_part;
-			disk_kobj = &part_to_dev(disk)->kobj;
+		disk = device->bdev->bd_part;
+		disk_kobj = &part_to_dev(disk)->kobj;
 
-			error = sysfs_create_link(fs_devices->devices_kobj,
-						  disk_kobj, disk_kobj->name);
-			if (error)
-				break;
+		ret = sysfs_create_link(devices_kobj, disk_kobj,
+					disk_kobj->name);
+		if (ret) {
+			btrfs_warn(device->fs_info,
+			   "sysfs create device link failed %d devid %llu",
+				   ret, device->devid);
+			goto out;
 		}
+	}
 
-		init_completion(&dev->kobj_unregister);
-		error = kobject_init_and_add(&dev->devid_kobj, &devid_ktype,
-					     fs_devices->devinfo_kobj, "%llu",
-					     dev->devid);
-		if (error) {
-			kobject_put(&dev->devid_kobj);
-			break;
-		}
+	init_completion(&device->kobj_unregister);
+	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
+				   devinfo_kobj, "%llu", device->devid);
+	if (ret) {
+		kobject_put(&device->devid_kobj);
+		btrfs_warn(device->fs_info,
+			   "sysfs devinfo init failed %d devid %llu",
+			   ret, device->devid);
 	}
+
+out:
 	memalloc_nofs_restore(nofs_flag);
+	return ret;
+}
 
-	return error;
+int btrfs_sysfs_add_devices_dir(struct btrfs_fs_devices *fs_devices,
+				struct btrfs_device *one_device)
+{
+	int ret;
+
+	if (one_device)
+		return btrfs_sysfs_add_device(one_device);
+
+	list_for_each_entry(one_device, &fs_devices->devices, dev_list) {
+		ret = btrfs_sysfs_add_device(one_device);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)