FIX: refreshes disk_space on backup create/destroy (#6169)

app/models/backup.rb

@@ -1,3 +1,5 @@
+require 'disk_space'
+
 class Backup
   include ActiveModel::SerializerSupport
 
@@ -36,6 +38,7 @@ class Backup
 
   def after_remove_hook
     remove_from_s3 if SiteSetting.enable_s3_backups? && !SiteSetting.s3_disable_cleanup?
+    DiskSpace.reset_cached_stats unless SiteSetting.enable_s3_backups?
   end
 
   def s3_bucket

lib/backup_restore/backuper.rb

@@ -1,3 +1,5 @@
+require 'disk_space'
+
 module BackupRestore
 
   class Backuper
@@ -276,9 +278,15 @@ module BackupRestore
       unpause_sidekiq
       disable_readonly_mode if Discourse.readonly_mode?
       mark_backup_as_not_running
+      refresh_disk_space
       log "Finished!"
     end
 
+    def refresh_disk_space
+      log "Refreshing disk cache..."
+      DiskSpace.reset_cached_stats
+    end
+
     def remove_tar_leftovers
       log "Removing '.tar' leftovers..."
       Dir["#{@archive_directory}/*.tar"].each { |filename| File.delete(filename) }

lib/disk_space.rb

@@ -2,6 +2,9 @@ class DiskSpace
 
   extend ActionView::Helpers::NumberHelper
 
+  DISK_SPACE_STATS_CACHE_KEY = 'disk_space_stats'.freeze
+  DISK_SPACE_STATS_UPDATED_CACHE_KEY = 'disk_space_stats_updated'.freeze
+
   def self.uploads_used_bytes
     # used(uploads_path)
     # temporary (on our internal setup its just too slow to iterate)
@@ -37,25 +40,36 @@ class DiskSpace
     }
   end
 
+  def self.reset_cached_stats
+    $redis.del(DISK_SPACE_STATS_UPDATED_CACHE_KEY)
+    $redis.del(DISK_SPACE_STATS_CACHE_KEY)
+    compute_disk_space
+  end
+
   def self.cached_stats
-    stats = $redis.get('disk_space_stats')
-    updated_at = $redis.get('disk_space_stats_updated')
+    stats = $redis.get(DISK_SPACE_STATS_CACHE_KEY)
+    updated_at = $redis.get(DISK_SPACE_STATS_UPDATED_CACHE_KEY)
 
     unless updated_at && (Time.now.to_i - updated_at.to_i) < 30.minutes
-      Scheduler::Defer.later "updated stats" do
-        $redis.set('disk_space_stats_updated', Time.now.to_i)
-        $redis.set('disk_space_stats', self.stats.to_json)
-      end
+      compute_disk_space
     end
 
     if stats
       JSON.parse(stats)
     end
-
   end
 
   protected
 
+  def self.compute_disk_space
+    Scheduler::Defer.later 'updated stats' do
+      $redis.set(DISK_SPACE_STATS_CACHE_KEY, self.stats.to_json)
+      $redis.set(DISK_SPACE_STATS_UPDATED_CACHE_KEY, Time.now.to_i)
+    end
+
+    nil
+  end
+
   def self.free(path)
     `df -Pk #{path} | awk 'NR==2 {print $4;}'`.to_i * 1024
   end