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>
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 7880687..b1502c4 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1420,6 +1420,10 @@
return -EIO;
}
+ error = gfs2_rindex_update(sdp);
+ if (error)
+ return error;
+
error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
return error;
@@ -1550,6 +1554,9 @@
out_unlock:
/* Error path for case 1 */
+ if (gfs2_rs_active(ip->i_res))
+ gfs2_rs_deltree(ip->i_res);
+
if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags))
gfs2_glock_dq(&ip->i_iopen_gh);
gfs2_holder_uninit(&ip->i_iopen_gh);