From: NeilBrown <neilb@suse.de>
Date: Sat, 14 Aug 2010 10:34:45 +0000 (+1000)
Subject: Refactor try_clean
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=e67be93c91a17879b45aee7a7a67a95355d93a0d;p=LaFS.git

Refactor try_clean

It is a very big function - change it to 3 moderate sized functions.

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

diff --git a/clean.c b/clean.c
index 7cff7c3..f2a8a7f 100644
--- a/clean.c
+++ b/clean.c
@@ -133,63 +133,61 @@ static void cleaner_flush(struct fs *fs)
 	lafs_cluster_flush(fs, 1);
 }
 
-static int try_clean(struct fs *fs, struct toclean *tc)
+static void cleaner_load(struct fs *fs, struct toclean *tc)
+{
+	/* Need to read in the cluster header */
+	int err;
+	err = lafs_load_page_async(fs, tc->chead,
+				   tc->haddr,
+				   (PAGE_SIZE /
+				    fs->blocksize),
+				   &tc->ac);
+
+	BUG_ON(err && err != -EAGAIN && err != -EIO);
+
+	if (err == -EAGAIN)
+		return;
+	if (err)
+		//printk("CLEANER got IO error !!\n");
+		// FIXME adjust youth to so as not to touch this again
+		goto bad_header;
+
+	tc->ch = page_address(tc->chead);
+	if (memcmp(tc->ch->idtag, "LaFSHead", 8) != 0)
+		goto bad_header;
+	if (memcmp(tc->ch->uuid, fs->state->uuid, 16) != 0)
+		goto bad_header;
+	if (tc->seq == 0)
+		tc->seq = le64_to_cpu(tc->ch->seq);
+	else {
+		tc->seq++;
+		if (tc->seq != le64_to_cpu(tc->ch->seq)) {
+			printk("Bad seq number\n");
+			goto bad_header;
+		}
+	}
+	tc->gh = tc->ch->groups;
+	tc->desc = tc->gh->u.desc;
+	if (lafs_calc_cluster_csum(tc->ch) != tc->ch->checksum) {
+		//printk("Cluster header checksum is wrong!!\n");
+		goto bad_header;
+	}
+	dprintk("try_clean: got header %d\n", (int)tc->haddr);
+	return;
+	
+bad_header:
+	tc->ac.state = 0;
+	tc->have_addr = 0;
+}
+
+static void cleaner_parse(struct fs *fs, struct toclean *tc)
 {
-	/* return 1 if everything has been found, -ve if we need to flush */
-	int again = 0;
 	u32 bnum;
 	int bcnt;
 	u32 inum, fsnum;
 	struct inode *ino = NULL;
-	struct datablock *b, *tmp;
-	int rv = 0;
 
-	mutex_lock(&fs->cleaner.lock);
-	dprintk("try_clean: state = %d\n", tc->ac.state);
-	if (tc->ch == NULL && tc->have_addr) {
-		/* Need to read in the cluster header */
-		int err;
-		err = lafs_load_page_async(fs, tc->chead,
-					   tc->haddr,
-					   (PAGE_SIZE /
-					    fs->blocksize),
-					   &tc->ac);
-
-		rv = 0;
-		if (err == -EAGAIN)
-			goto out;
-		if (err == -EIO) {
-			//printk("CLEANER got IO error !!\n");
-			// FIXME adjust youth to so as not to touch this again
-		bad_header:
-			tc->ac.state = 0;
-			tc->have_addr = 0;
-			rv = 0;
-			goto out;
-		}
-		BUG_ON(err);
-		tc->ch = page_address(tc->chead);
-		if (memcmp(tc->ch->idtag, "LaFSHead", 8) != 0)
-			goto bad_header;
-		if (memcmp(tc->ch->uuid, fs->state->uuid, 16) != 0)
-			goto bad_header;
-		if (tc->seq == 0)
-			tc->seq = le64_to_cpu(tc->ch->seq);
-		else {
-			tc->seq++;
-			if (tc->seq != le64_to_cpu(tc->ch->seq)) {
-				printk("Bad seq number\n");
-				goto bad_header;
-			}
-		}
-		tc->gh = tc->ch->groups;
-		tc->desc = tc->gh->u.desc;
-		if (lafs_calc_cluster_csum(tc->ch) != tc->ch->checksum) {
-			//printk("Cluster header checksum is wrong!!\n");
-			goto bad_header;
-		}
-		dprintk("try_clean: got header %d\n", (int)tc->haddr);
-	}
+	int again = 0;
 	while (tc->ch && again < 16) {
 		/* Load the index block for each described data or index block.
 		 * For data blocks, get the address and possibly load the
@@ -283,6 +281,7 @@ static int try_clean(struct fs *fs, struct toclean *tc)
 			}
 			break;
 		} else {
+			struct datablock *b;
 			dprintk("got the inode\n");
 			/* Minor optimisation for files that have shrunk */
 			/* Actually this is critical for handling truncation
@@ -341,6 +340,14 @@ static int try_clean(struct fs *fs, struct toclean *tc)
 	}
 	if (ino)
 		iput(ino);
+}
+
+static int cleaner_process(struct fs *fs, struct toclean *tc)
+{
+	struct datablock *b, *tmp;
+	int rv = 0;
+	struct inode *ino;
+
 	dprintk("start processing list\n");
 	list_for_each_entry_safe(b, tmp, &tc->cleaning, cleaning) {
 		struct block *cb = NULL;
@@ -400,11 +407,29 @@ static int try_clean(struct fs *fs, struct toclean *tc)
 		iput(ino);
 		putref(cb, MKREF(clean2));
 		if (rv)
-			goto out;
+			break;
 	}
-	rv = tc->ch == NULL && !tc->have_addr &&
-		list_empty(&tc->cleaning);
-out:
+	return rv;
+}
+
+static int try_clean(struct fs *fs, struct toclean *tc)
+{
+	/* return 1 if everything has been found, -ve if we need to flush */
+	int rv = 0;
+
+	mutex_lock(&fs->cleaner.lock);
+	dprintk("try_clean: state = %d\n", tc->ac.state);
+	if (tc->ch == NULL && tc->have_addr)
+		cleaner_load(fs, tc);
+
+	if (tc->ch)
+		cleaner_parse(fs, tc);
+
+	if (!list_empty(&tc->cleaning))
+		rv = cleaner_process(fs, tc);
+	if (!rv)
+		rv = (tc->ch == NULL && !tc->have_addr &&
+		      list_empty(&tc->cleaning));
 	mutex_unlock(&fs->cleaner.lock);
 	return rv;
 }