From: NeilBrown <neilb@suse.de>
Date: Sat, 3 Jul 2010 01:00:20 +0000 (+1000)
Subject: Avoid overallocation to the cleaner
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=a25e8ccb52445d319d4dcdc65086f4f5e8256de8;p=LaFS.git

Avoid overallocation to the cleaner

Don't give space to the cleaner at the expense of space for
writing new blocks.  That would be greedy.

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

diff --git a/segments.c b/segments.c
index 5570360..2733b1a 100644
--- a/segments.c
+++ b/segments.c
@@ -574,12 +574,16 @@ int lafs_alloc_cleaner_segs(struct fs *fs, int max)
 	/* cleaner is about to start.
 	 * See how many segments of space can safely
 	 * be reserved for its use.
+	 * We don't allocate more to the cleaner than we
+	 * leave spare for new allocations.
 	 */
 	int watermark = fs->max_segment * 4;
 	int rv = 0;
 	spin_lock(&fs->alloc_lock);
 	while (fs->clean_reserved < max * fs->max_segment &&
-	       fs->free_blocks > fs->allocated_blocks + watermark) {
+	       fs->free_blocks > (fs->clean_reserved
+				  + fs->allocated_blocks
+				  + watermark)) {
 		fs->clean_reserved += fs->max_segment;
 		fs->free_blocks -= fs->max_segment;
 		rv++;