[Cluster-devel] [GFS2 Patch] [TRY #2] GFS2: Combine functions get_local_rgrp and gfs2_inplace_reserve

[Bob Peterson]

Hi,

This function combines rgrp functions get_local_rgrp and
gfs2_inplace_reserve so that the double retry loop is gone.

The patch needed some adjustments due to upstream changes
that made its predecessor not apply, as Steve mentioned earlier.

Regards,

Bob Peterson
Red Hat File Systems

Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
---
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 3c6f7ed..e53d0a1 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1207,25 +1207,30 @@ static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip
 }
 
 /**
- * get_local_rgrp - Choose and lock a rgrp for allocation
+ * gfs2_inplace_reserve - Reserve space in the filesystem
  * @ip: the inode to reserve space for
- * @last_unlinked: the last unlinked block
- *
- * Try to acquire rgrp in way which avoids contending with others.
+ * @requested: the number of blocks to be reserved
  *
  * Returns: errno
  */
 
-static int get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked)
+int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 	struct gfs2_rgrpd *rgd, *begin = NULL;
 	struct gfs2_blkreserv *rs = ip->i_res;
-	int error, rg_locked, flags = LM_FLAG_TRY;
+	int error = 0, rg_locked, flags = LM_FLAG_TRY;
+	u64 last_unlinked = NO_BLOCK;
 	int loops = 0;
 
 	if (sdp->sd_args.ar_rgrplvb)
 		flags |= GL_SKIP;
+	rs = ip->i_res;
+	rs->rs_requested = requested;
+	if (gfs2_assert_warn(sdp, requested)) {
+		error = -EINVAL;
+		goto out;
+	}
 
 	if (ip->i_rgd && rgrp_contains_block(ip->i_rgd, ip->i_goal))
 		rgd = begin = ip->i_rgd;
@@ -1263,63 +1268,34 @@ static int get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked)
 			if (rgd->rd_flags & GFS2_RDF_CHECK) {
 				if (sdp->sd_args.ar_rgrplvb)
 					gfs2_rgrp_bh_get(rgd);
-				try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr);
+				try_rgrp_unlink(rgd, &last_unlinked,
+						ip->i_no_addr);
 			}
 			if (!rg_locked)
 				gfs2_glock_dq_uninit(&rs->rs_rgd_gh);
 			/* fall through */
 		case GLR_TRYFAILED:
 			rgd = gfs2_rgrpd_get_next(rgd);
-			if (rgd == begin) {
-				flags &= ~LM_FLAG_TRY;
-				loops++;
-			}
+			if (rgd != begin) /* If we didn't wrap */
+				break;
+
+			flags &= ~LM_FLAG_TRY;
+			loops++;
+			/* Check that fs hasn't grown if writing to rindex */
+			if (ip == GFS2_I(sdp->sd_rindex) &&
+			    !sdp->sd_rindex_uptodate) {
+				error = gfs2_ri_update(ip);
+				if (error)
+					goto out;
+			} else if (loops == 2)
+				/* Flushing the log may release space */
+				gfs2_log_flush(sdp, NULL);
 			break;
 		default:
-			return error;
+			goto out;
 		}
 	}
-
-	return -ENOSPC;
-}
-
-/**
- * gfs2_inplace_reserve - Reserve space in the filesystem
- * @ip: the inode to reserve space for
- * @requested: the number of blocks to be reserved
- *
- * Returns: errno
- */
-
-int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested)
-{
-	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-	struct gfs2_blkreserv *rs;
-	int error = 0;
-	u64 last_unlinked = NO_BLOCK;
-	int tries = 0;
-
-	rs = ip->i_res;
-	rs->rs_requested = requested;
-	if (gfs2_assert_warn(sdp, requested)) {
-		error = -EINVAL;
-		goto out;
-	}
-
-	do {
-		error = get_local_rgrp(ip, &last_unlinked);
-		if (error != -ENOSPC)
-			break;
-		/* Check that fs hasn't grown if writing to rindex */
-		if (ip == GFS2_I(sdp->sd_rindex) && !sdp->sd_rindex_uptodate) {
-			error = gfs2_ri_update(ip);
-			if (error)
-				break;
-			continue;
-		}
-		/* Flushing the log may release space */
-		gfs2_log_flush(sdp, NULL);
-	} while (tries++ < 3);
+	error = -ENOSPC;
 
 out:
 	if (error)