Btrfs: simplify iteration codes

Merge list_for_each* and list_entry to list_for_each_entry*

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 397c8db..fd0bedb 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -103,10 +103,8 @@
 						   u64 devid, u8 *uuid)
 {
 	struct btrfs_device *dev;
-	struct list_head *cur;
 
-	list_for_each(cur, head) {
-		dev = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry(dev, head, dev_list) {
 		if (dev->devid == devid &&
 		    (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
 			return dev;
@@ -117,11 +115,9 @@
 
 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
 {
-	struct list_head *cur;
 	struct btrfs_fs_devices *fs_devices;
 
-	list_for_each(cur, &fs_uuids) {
-		fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
+	list_for_each_entry(fs_devices, &fs_uuids, list) {
 		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
 			return fs_devices;
 	}
@@ -344,14 +340,11 @@
 
 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 {
-	struct list_head *tmp;
-	struct list_head *cur;
-	struct btrfs_device *device;
+	struct btrfs_device *device, *next;
 
 	mutex_lock(&uuid_mutex);
 again:
-	list_for_each_safe(cur, tmp, &fs_devices->devices) {
-		device = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
 		if (device->in_fs_metadata)
 			continue;
 
@@ -382,14 +375,12 @@
 
 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 {
-	struct list_head *cur;
 	struct btrfs_device *device;
 
 	if (--fs_devices->opened > 0)
 		return 0;
 
-	list_for_each(cur, &fs_devices->devices) {
-		device = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		if (device->bdev) {
 			close_bdev_exclusive(device->bdev, device->mode);
 			fs_devices->open_devices--;
@@ -438,7 +429,6 @@
 {
 	struct block_device *bdev;
 	struct list_head *head = &fs_devices->devices;
-	struct list_head *cur;
 	struct btrfs_device *device;
 	struct block_device *latest_bdev = NULL;
 	struct buffer_head *bh;
@@ -449,8 +439,7 @@
 	int seeding = 1;
 	int ret = 0;
 
-	list_for_each(cur, head) {
-		device = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry(device, head, dev_list) {
 		if (device->bdev)
 			continue;
 		if (!device->name)
@@ -1016,14 +1005,12 @@
 	}
 
 	if (strcmp(device_path, "missing") == 0) {
-		struct list_head *cur;
 		struct list_head *devices;
 		struct btrfs_device *tmp;
 
 		device = NULL;
 		devices = &root->fs_info->fs_devices->devices;
-		list_for_each(cur, devices) {
-			tmp = list_entry(cur, struct btrfs_device, dev_list);
+		list_for_each_entry(tmp, devices, dev_list) {
 			if (tmp->in_fs_metadata && !tmp->bdev) {
 				device = tmp;
 				break;
@@ -1279,7 +1266,6 @@
 	struct btrfs_trans_handle *trans;
 	struct btrfs_device *device;
 	struct block_device *bdev;
-	struct list_head *cur;
 	struct list_head *devices;
 	struct super_block *sb = root->fs_info->sb;
 	u64 total_bytes;
@@ -1303,8 +1289,7 @@
 	mutex_lock(&root->fs_info->volume_mutex);
 
 	devices = &root->fs_info->fs_devices->devices;
-	list_for_each(cur, devices) {
-		device = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry(device, devices, dev_list) {
 		if (device->bdev == bdev) {
 			ret = -EEXIST;
 			goto error;
@@ -1703,7 +1688,6 @@
 int btrfs_balance(struct btrfs_root *dev_root)
 {
 	int ret;
-	struct list_head *cur;
 	struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
 	struct btrfs_device *device;
 	u64 old_size;
@@ -1722,8 +1706,7 @@
 	dev_root = dev_root->fs_info->dev_root;
 
 	/* step one make some room on all the devices */
-	list_for_each(cur, devices) {
-		device = list_entry(cur, struct btrfs_device, dev_list);
+	list_for_each_entry(device, devices, dev_list) {
 		old_size = device->total_bytes;
 		size_to_free = div_factor(old_size, 1);
 		size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);