Btrfs: cleanup unused latest_devid and latest_trans in fs_devices

The member variants - latest_devid and latest_trans - of fs_devices structure
are set, but no one use them to do anything. so remove them.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 11 insertions, 31 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e04424490f12..46cd29ad3156 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -475,14 +475,13 @@ static noinline int device_list_add(const char *path,
                         return PTR_ERR(fs_devices);
 
                 list_add(&fs_devices->list, &fs_uuids);
-                fs_devices->latest_devid = devid;
-                fs_devices->latest_trans = found_transid;
 
                 device = NULL;
         } else {
                 device = __find_device(&fs_devices->devices, devid,
                                        disk_super->dev_item.uuid);
         }
+
         if (!device) {
                 if (fs_devices->opened)
                         return -EBUSY;
@@ -567,10 +566,6 @@ static noinline int device_list_add(const char *path,
         if (!fs_devices->opened)
                 device->generation = found_transid;
 
-        if (found_transid > fs_devices->latest_trans) {
-                fs_devices->latest_devid = devid;
-                fs_devices->latest_trans = found_transid;
-        }
         *fs_devices_ret = fs_devices;
 
         return ret;
@@ -586,8 +581,6 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
         if (IS_ERR(fs_devices))
                 return fs_devices;
 
-        fs_devices->latest_devid = orig->latest_devid;
-        fs_devices->latest_trans = orig->latest_trans;
         fs_devices->total_devices = orig->total_devices;
 
         /* We have held the volume lock, it is safe to get the devices. */
@@ -626,10 +619,7 @@ void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
                                struct btrfs_fs_devices *fs_devices, int step)
 {
         struct btrfs_device *device, *next;
-
-        struct block_device *latest_bdev = NULL;
-        u64 latest_devid = 0;
-        u64 latest_transid = 0;
+        struct btrfs_device *latest_dev = NULL;
 
         mutex_lock(&uuid_mutex);
 again:
@@ -637,11 +627,9 @@ again:
         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
                 if (device->in_fs_metadata) {
                         if (!device->is_tgtdev_for_dev_replace &&
-                            (!latest_transid ||
-                             device->generation > latest_transid)) {
-                                latest_devid = device->devid;
-                                latest_transid = device->generation;
-                                latest_bdev = device->bdev;
+                            (!latest_dev ||
+                             device->generation > latest_dev->generation)) {
+                                latest_dev = device;
                         }
                         continue;
                 }
@@ -683,9 +671,7 @@ again:
                 goto again;
         }
 
-        fs_devices->latest_bdev = latest_bdev;
-        fs_devices->latest_devid = latest_devid;
-        fs_devices->latest_trans = latest_transid;
+        fs_devices->latest_bdev = latest_dev->bdev;
 
         mutex_unlock(&uuid_mutex);
 }
@@ -800,11 +786,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
         struct block_device *bdev;
         struct list_head *head = &fs_devices->devices;
         struct btrfs_device *device;
-        struct block_device *latest_bdev = NULL;
+        struct btrfs_device *latest_dev = NULL;
         struct buffer_head *bh;
         struct btrfs_super_block *disk_super;
-        u64 latest_devid = 0;
-        u64 latest_transid = 0;
         u64 devid;
         int seeding = 1;
         int ret = 0;
@@ -832,11 +816,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                         goto error_brelse;
 
                 device->generation = btrfs_super_generation(disk_super);
-                if (!latest_transid || device->generation > latest_transid) {
-                        latest_devid = devid;
-                        latest_transid = device->generation;
-                        latest_bdev = bdev;
-                }
+                if (!latest_dev ||
+                    device->generation > latest_dev->generation)
+                        latest_dev = device;
 
                 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
                         device->writeable = 0;
@@ -879,9 +861,7 @@ error_brelse:
         }
         fs_devices->seeding = seeding;
         fs_devices->opened = 1;
-        fs_devices->latest_bdev = latest_bdev;
-        fs_devices->latest_devid = latest_devid;
-        fs_devices->latest_trans = latest_transid;
+        fs_devices->latest_bdev = latest_dev->bdev;
         fs_devices->total_rw_bytes = 0;
 out:
         return ret;