btrfs: create helper function __check_raid_min_devices()

move a section of btrfs_rm_device() code to check for min number of the
devices into the function __check_raid_min_devices()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5006683..db781d0 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1705,23 +1705,20 @@ out:
        return ret;
 }
 
-int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+static int __check_raid_min_devices(struct btrfs_root *root)
 {
-       struct btrfs_device *device;
-       struct btrfs_device *next_device;
-       struct block_device *bdev;
-       struct buffer_head *bh = NULL;
-       struct btrfs_super_block *disk_super;
-       struct btrfs_fs_devices *cur_devices;
        u64 all_avail;
-       u64 devid;
        u64 num_devices;
-       u8 *dev_uuid;
        unsigned seq;
        int ret = 0;
-       bool clear_super = false;
 
-       mutex_lock(&uuid_mutex);
+       num_devices = root->fs_info->fs_devices->num_devices;
+       btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
+       if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
+               WARN_ON(num_devices < 1);
+               num_devices--;
+       }
+       btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
 
        do {
                seq = read_seqbegin(&root->fs_info->profiles_lock);
@@ -1731,14 +1728,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                            root->fs_info->avail_metadata_alloc_bits;
        } while (read_seqretry(&root->fs_info->profiles_lock, seq));
 
-       num_devices = root->fs_info->fs_devices->num_devices;
-       btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
-       if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
-               WARN_ON(num_devices < 1);
-               num_devices--;
-       }
-       btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
-
        if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
                ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
                goto out;
@@ -1760,6 +1749,30 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                goto out;
        }
 
+out:
+       return ret;
+}
+
+int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+{
+       struct btrfs_device *device;
+       struct btrfs_device *next_device;
+       struct block_device *bdev;
+       struct buffer_head *bh = NULL;
+       struct btrfs_super_block *disk_super;
+       struct btrfs_fs_devices *cur_devices;
+       u64 devid;
+       u64 num_devices;
+       u8 *dev_uuid;
+       int ret = 0;
+       bool clear_super = false;
+
+       mutex_lock(&uuid_mutex);
+
+       ret = __check_raid_min_devices(root);
+       if (ret)
+               goto out;
+
        if (strcmp(device_path, "missing") == 0) {
                struct list_head *devices;
                struct btrfs_device *tmp;