From: NeilBrown <neilb@suse.de>
Date: Fri, 2 Jul 2010 23:29:34 +0000 (+1000)
Subject: Close segments properly when we get to the end.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=5741cd613a397acbfcd30fdb56fa3c8addcf862d;p=LaFS.git

Close segments properly when we get to the end.

Passing -1 to new_segment was just *wrong*.
Do it right, and make sure to close all segments, and
release refcounts, at unmount.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/cluster.c b/cluster.c
index 5569205..526fb9d 100644
--- a/cluster.c
+++ b/cluster.c
@@ -396,26 +396,46 @@ static void cluster_reset(struct fs *fs, struct wc *wc)
 	
 }
 
-static int new_segment(struct fs *fs, int cnum)
+static void close_segment(struct fs *fs, int cnum)
 {
-	/* new_segment can fail if cnum > 0 and there is no
-	 * clean_reserved
-	 */
-	struct wc *wc = fs->wc + cnum;
-	unsigned int dev;
-	u32 seg;
-
 	/* Release old segment */
 	/* FIXME I need lafs_seg_{de,}ref for every snapshot,
 	 * don't I ???
 	 */
+	struct wc *wc = fs->wc + cnum;
 	if (wc->seg.dev >= 0) {
+		if (cnum) {
+			spin_lock(&fs->lock);
+			fs->clean_reserved -= seg_remainder(fs, &wc->seg);
+			spin_unlock(&fs->lock);
+		}
 		lafs_seg_forget(fs, wc->seg.dev, wc->seg.num);
 		wc->seg.dev = -1;
 	}
+}
 
-	if (cnum < 0 ||
-	    (cnum && fs->clean_reserved < fs->max_segment))
+void lafs_close_all_segments(struct fs *fs)
+{
+	int cnum;
+	for (cnum = 0; cnum < WC_NUM; cnum++)
+		close_segment(fs, cnum);
+}
+
+static int new_segment(struct fs *fs, int cnum)
+{
+	/* new_segment can fail if cnum > 0 and there is no
+	 * clean_reserved
+	 */
+	struct wc *wc = fs->wc + cnum;
+	unsigned int dev;
+	u32 seg;
+
+	close_segment(fs, cnum);
+
+	/* FIXME if clean_reserve is too small, maybe
+	 * clear it completely.
+	 */
+	if ((cnum && fs->clean_reserved < fs->max_segment))
 			return -ENOSPC;
 	/* This gets a reference on the 'segsum' */
 	lafs_free_get(fs, &dev, &seg, 0);
@@ -1194,7 +1214,7 @@ static void cluster_flush(struct fs *fs, int cnum)
 		if (cnum == 0)
 			new_segment(fs, cnum);
 		else
-			new_segment(fs, -1);
+			close_segment(fs, cnum);
 	}
 
 	/* Fill in the cluster header */
diff --git a/lafs.h b/lafs.h
index 78cadfd..7c9928a 100644
--- a/lafs.h
+++ b/lafs.h
@@ -648,6 +648,7 @@ int lafs_calc_cluster_csum(struct cluster_head *head);
 int lafs_cluster_init(struct fs *fs, int cnum, u64 addr, u64 prev, u64 seq);
 void lafs_clusters_done(struct fs *fs);
 void lafs_done_work(struct work_struct *ws);
+void lafs_close_all_segments(struct fs *fs);
 
 /* index.c */
 void lafs_pin_block_ph(struct block *b, int ph);
diff --git a/super.c b/super.c
index 71f5098..efc2071 100644
--- a/super.c
+++ b/super.c
@@ -732,6 +732,7 @@ lafs_put_super(struct super_block *sb)
 		set_bit(FinalCheckpoint, &fs->fsstate);
 		lafs_checkpoint_unlock_wait(fs);
 		lafs_cluster_wait_all(fs);
+		lafs_close_all_segments(fs);
 		lafs_empty_segment_table(fs);
 		lafs_seg_put_all(fs);