GFS2: Use cached rgrp in gfs2_rlist_add()

Each block which is deallocated, requires a call to gfs2_rlist_add()
and each of those calls was calling gfs2_blk2rgrpd() in order to
figure out which rgrp the block belonged in. This can be speeded up
by making use of the rgrp cached in the inode. We also reset this
cached rgrp in case the block has changed rgrp. This should provide
a big reduction in gfs2_blk2rgrpd() calls during deallocation.

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

1 files changed, 9 insertions, 5 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 08b3a8002aca..3088fb25656d 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1560,7 +1560,7 @@ fail:
 
 /**
  * gfs2_rlist_add - add a RG to a list of RGs
- * @sdp: the filesystem
+ * @ip: the inode
  * @rlist: the list of resource groups
  * @block: the block
  *
@@ -1570,9 +1570,10 @@ fail:
  *
  */
 
-void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
+void gfs2_rlist_add(struct gfs2_inode *ip, struct gfs2_rgrp_list *rlist,
                     u64 block)
 {
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_rgrpd *rgd;
         struct gfs2_rgrpd **tmp;
         unsigned int new_space;
@@ -1581,12 +1582,15 @@ void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
         if (gfs2_assert_warn(sdp, !rlist->rl_ghs))
                 return;
 
-        rgd = gfs2_blk2rgrpd(sdp, block);
+        if (ip->i_rgd && rgrp_contains_block(ip->i_rgd, block))
+                rgd = ip->i_rgd;
+        else
+                rgd = gfs2_blk2rgrpd(sdp, block);
         if (!rgd) {
-                if (gfs2_consist(sdp))
-                        fs_err(sdp, "block = %llu\n", (unsigned long long)block);
+                fs_err(sdp, "rlist_add: no rgrp for block %llu\n", (unsigned long long)block);
                 return;
         }
+        ip->i_rgd = rgd;
 
         for (x = 0; x < rlist->rl_rgrps; x++)
                 if (rlist->rl_rgd[x] == rgd)