xfs: add background scanning to clear eofblocks inodes

Create a new mount workqueue and delayed_work to enable background
scanning and freeing of eofblocks inodes. The scanner kicks in once
speculative preallocation occurs and stops requeueing itself when
no eofblocks inodes exist.

The scan interval is based on the new
'speculative_prealloc_lifetime' tunable (default to 5m). The
background scanner performs unfiltered, best effort scans (which
skips inodes under lock contention or with a dirty cache mapping).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index a631ca3b9065..dc306a09f56f 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -196,6 +196,8 @@ typedef struct xfs_mount {
 #endif
         struct xfs_mru_cache    *m_filestream;  /* per-mount filestream data */
         struct delayed_work     m_reclaim_work; /* background inode reclaim */
+        struct delayed_work     m_eofblocks_work; /* background eof blocks
+                                                     trimming */
         __int64_t               m_update_flags; /* sb flags we need to update
                                                    on the next remount,rw */
         struct shrinker         m_inode_shrink; /* inode reclaim shrinker */
@@ -207,6 +209,7 @@ typedef struct xfs_mount {
         struct workqueue_struct *m_cil_workqueue;
         struct workqueue_struct *m_reclaim_workqueue;
         struct workqueue_struct *m_log_workqueue;
+        struct workqueue_struct *m_eofblocks_workqueue;
 } xfs_mount_t;
 
 /*