GFS2: Reduce file fragmentation

This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
index 523c0de0d805..27a0b4a901f5 100644
--- a/fs/gfs2/xattr.c
+++ b/fs/gfs2/xattr.c
@@ -327,6 +327,10 @@ static int ea_remove_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
 {
         int error;
 
+        error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
+        if (error)
+                return error;
+
         error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
         if (error)
                 goto out_alloc;
@@ -710,6 +714,10 @@ static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
         struct buffer_head *dibh;
         int error;
 
+        error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
+        if (error)
+                return error;
+
         error = gfs2_quota_lock_check(ip);
         if (error)
                 return error;
@@ -1483,6 +1491,10 @@ int gfs2_ea_dealloc(struct gfs2_inode *ip)
 {
         int error;
 
+        error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
+        if (error)
+                return error;
+
         error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
         if (error)
                 return error;