From: NeilBrown <neilb@suse.de>
Date: Sat, 2 Oct 2010 04:31:21 +0000 (+1000)
Subject: Don't use I_ICredit for UnincCredit when cleaning.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=9f5dbbc17ecfcd2e9158b7072da42731a91a633e;p=LaFS.git

Don't use I_ICredit for UnincCredit when cleaning.

ICredit is only to be used when dirtying a block, so any setting of
UnincCredit for cleaning must get the credit from elsewhere.  If no
such credit is available, fall back on dirtying the block.

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

diff --git a/clean.c b/clean.c
index f135cf5..ed37560 100644
--- a/clean.c
+++ b/clean.c
@@ -17,6 +17,7 @@
 static int mark_cleaning(struct block *b)
 {
 	int err;
+	int credits;
 
 	if (test_bit(B_Realloc, &b->flags))
 		/* As cleaning is single threaded,
@@ -29,13 +30,12 @@ static int mark_cleaning(struct block *b)
 	if (err)
 		return err;
 	LAFS_BUG(!test_bit(B_Valid, &b->flags), b);
-	if (!test_bit(B_Realloc, &b->flags)) {
-		if (lafs_space_alloc(fs_from_inode(b->inode), 1, CleanSpace) == 1) {
-			if (test_and_set_bit(B_Realloc, &b->flags))
-				lafs_space_return(fs_from_inode(b->inode), 1);
-		} else
-			return -EAGAIN;
-	}
+	credits = lafs_space_alloc(fs_from_inode(b->inode), 2, CleanSpace);
+	if (credits == 0)
+		return -EAGAIN;
+	if (!test_and_set_bit(B_Realloc, &b->flags))
+		credits--;
+
 	lafs_pin_block(b);
 	if (test_bit(B_Dirty, &b->flags)) {
 		/* If dirty, then now that it is pinned,
@@ -43,14 +43,12 @@ static int mark_cleaning(struct block *b)
 		 * Realloc
 		 */
 		if (test_and_clear_bit(B_Realloc, &b->flags))
-			if (test_and_set_bit(B_Credit, &b->flags))
-				lafs_space_return(fs_from_inode(b->inode), 1);
-		return 0;
+			credits++;
 	}
 
 	if (!test_and_set_bit(B_UnincCredit, &b->flags))
-		if (!test_and_clear_bit(B_ICredit, &b->flags))
-			LAFS_BUG(1, b); // ICredit should be set before we dirty a block.
+		credits--;
+	lafs_space_return(fs_from_inode(b->inode), credits);
 
 	lafs_refile(b, 0);
 	lafs_refile(&b->parent->b, 0);
diff --git a/cluster.c b/cluster.c
index b94387a..168426f 100644
--- a/cluster.c
+++ b/cluster.c
@@ -531,13 +531,13 @@ static int flush_data_to_inode(struct block *b)
 		int credits = 1;
 		LAFS_BUG(!test_bit(B_Valid, &lai->iblock->b.flags),
 			 &lai->iblock->b);
+		if (test_and_clear_bit(B_UnincCredit, &b->flags))
+			credits++;
 		if (!test_and_set_bit(B_Realloc, &lai->iblock->b.flags))
 			credits--;
 		if (!test_and_set_bit(B_UnincCredit, &lai->iblock->b.flags))
-			if (!test_and_clear_bit(B_ICredit,
-						&lai->iblock->b.flags))
-				if (!test_and_clear_bit(B_UnincCredit, &b->flags))
-					LAFS_BUG(1, b); /* We needed an UnincCredit */
+			credits--;
+		LAFS_BUG(credits < 0, b);
 		lafs_space_return(fs, credits);
 	} else {
 		printk("Wasn't dirty or realloc: %s\n", strblk(b));
@@ -689,17 +689,20 @@ int lafs_cluster_allocate(struct block *b, int cnum)
 		 */
 		LAFS_BUG(!test_bit(B_Valid, &b2->flags), b2);
 
-		if (!test_and_set_bit(B_UnincCredit, &b2->flags))
-			if (!test_and_clear_bit(B_ICredit, &b2->flags))
-				credits--;
-
 		if (cnum == 0) {
+			if (!test_and_set_bit(B_UnincCredit, &b2->flags))
+				if (!test_and_clear_bit(B_ICredit, &b2->flags))
+					credits--;
+
 			if (!test_bit(B_Dirty, &b2->flags))
 				/* need some credits... */
 				if (!test_and_set_bit(B_Credit, &b2->flags))
 					credits--;
 			lafs_dirty_dblock(dblk(b2));
 		} else {
+			if (!test_and_set_bit(B_UnincCredit, &b2->flags))
+				credits--;
+
 			if (!test_and_set_bit(B_Realloc, &b2->flags))
 				credits--;
 		}
diff --git a/index.c b/index.c
index 5fa3037..32af941 100644
--- a/index.c
+++ b/index.c
@@ -2203,11 +2203,14 @@ new_parent:
 			} else
 				lafs_dirty_iblock(p);
 		}
-		if (!test_and_set_bit(B_UnincCredit, &p->b.flags))
-			if (!test_and_clear_bit(B_ICredit, &p->b.flags))
-				LAFS_BUG(1, &p->b); // ICredit should be set before
-		//we dirty a block.
-
+		if (!test_bit(B_UnincCredit, &p->b.flags)) {
+			/* Ditto for UnincCredit */
+			if (lafs_space_alloc(fs, 1, CleanSpace) == 1) {
+				if (test_and_set_bit(B_UnincCredit, &p->b.flags))
+					lafs_space_return(fs, 1);
+			} else
+				lafs_dirty_iblock(p);
+		}
 	}
 
 	dprintk("Uninc same phase\n");