Btrfs: cleanup unused num_can_discard in fs_devices

The member variants - num_can_discard - 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>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e9676a42430946aa5f6cec00cf63912140021353..483fc6d45299c7074c1b9734eebcc07e6303f0d6 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -720,8 +720,6 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                        fs_devices->rw_devices--;
                }
 
-               if (device->can_discard)
-                       fs_devices->num_can_discard--;
                if (device->missing)
                        fs_devices->missing_devices--;
 
@@ -828,10 +826,8 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                }
 
                q = bdev_get_queue(bdev);
-               if (blk_queue_discard(q)) {
+               if (blk_queue_discard(q))
                        device->can_discard = 1;
-                       fs_devices->num_can_discard++;
-               }
 
                device->bdev = bdev;
                device->in_fs_metadata = 0;
@@ -1835,8 +1831,7 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
                if (!fs_devices->seeding)
                        fs_devices->rw_devices++;
        }
-       if (srcdev->can_discard)
-               fs_devices->num_can_discard--;
+
        if (srcdev->bdev) {
                fs_devices->open_devices--;
 
@@ -1886,8 +1881,6 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
                fs_info->fs_devices->open_devices--;
        }
        fs_info->fs_devices->num_devices--;
-       if (tgtdev->can_discard)
-               fs_info->fs_devices->num_can_discard++;
 
        next_device = list_entry(fs_info->fs_devices->devices.next,
                                 struct btrfs_device, dev_list);
@@ -2008,7 +2001,6 @@ static int btrfs_prepare_sprout(struct btrfs_root *root)
        fs_devices->num_devices = 0;
        fs_devices->open_devices = 0;
        fs_devices->missing_devices = 0;
-       fs_devices->num_can_discard = 0;
        fs_devices->rotating = 0;
        fs_devices->seed = seed_devices;
 
@@ -2200,8 +2192,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        root->fs_info->fs_devices->open_devices++;
        root->fs_info->fs_devices->rw_devices++;
        root->fs_info->fs_devices->total_devices++;
-       if (device->can_discard)
-               root->fs_info->fs_devices->num_can_discard++;
        root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
 
        spin_lock(&root->fs_info->free_chunk_lock);
@@ -2371,8 +2361,6 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
        list_add(&device->dev_list, &fs_info->fs_devices->devices);
        fs_info->fs_devices->num_devices++;
        fs_info->fs_devices->open_devices++;
-       if (device->can_discard)
-               fs_info->fs_devices->num_can_discard++;
        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
        *device_out = device;

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index e894ac696889b99acec84c5de40b1dedba6fa3e8..37f8bff97df119cbbceaed964d93861f3448873d 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -124,7 +124,6 @@ struct btrfs_fs_devices {
        u64 rw_devices;
        u64 missing_devices;
        u64 total_rw_bytes;
-       u64 num_can_discard;
        u64 total_devices;
        struct block_device *latest_bdev;