From: NeilBrown <neilb@suse.de>
Date: Sat, 18 Sep 2010 12:40:54 +0000 (+1000)
Subject: Use segsum rather than separate dblock for youth in lafs_free_get
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=7149d4aff74f55e330738a508c56daee586dbf79;p=LaFS.git

Use segsum rather than separate dblock for youth in lafs_free_get

As segsum now always have a youthblk for ss==0, we don't need to
separately find a data block.

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

diff --git a/segments.c b/segments.c
index 66d47eb..847c144 100644
--- a/segments.c
+++ b/segments.c
@@ -1062,10 +1062,9 @@ void lafs_free_get(struct fs *fs, unsigned int *dev, u32 *seg,
 	 * The youth value must have been zero, and we set it to the
 	 * current youth number.
 	 */
-	struct datablock *db = NULL;
 	u16 *youthp;
 	struct segstat *ss;
-	struct segsum *ssum;
+	struct segsum *ssum = NULL;
 	int ssnum;
 
 	BUG_ON(nonlogged); // FIXME should handle this case, not ignore it
@@ -1091,24 +1090,22 @@ again:
 	 * updates to the Youth block.
 	 */
 	if (!test_bit(FinalCheckpoint, &fs->fsstate) &&
-	    !(db &&
-	      db->b.inode == fs->devs[*dev].segsum &&
-	      db->b.fileaddr == ((*seg) >> (fs->blocksize_bits
-					    - 1)))) {
+	    !(ssum &&
+	      ssum->devnum == ss->dev &&
+	      ssum->segnum == ss->segment)) {
 		spin_unlock(&fs->lock);
-		if (db)
-			putdref(db, MKREF(youth));
-
-		db = lafs_get_block(fs->devs[*dev].segsum,
-				    (*seg) >> (fs->blocksize_bits
-					       - 1),
-				    NULL, GFP_KERNEL,
-				    MKREF(youth));
+		if (ssum)
+			ss_put(ssum, fs);
+
+		ssum = segsum_find(fs, ss->segment, ss->dev, 0);
 		/* As we hold a ref on youth block for anything in the
 		 * table, and that block was loaded at the time, it must
 		 * still be valid.
 		 */
-		BUG_ON(!test_bit(B_Valid, &db->b.flags));
+		BUG_ON(!ssum || !ssum->youthblk);
+		BUG_ON(!test_bit(B_Valid, &ssum->youthblk->b.flags));
+		set_bit(B_PinPending, &ssum->youthblk->b.flags);
+		lafs_pin_dblock(ssum->youthblk, AccountSpace);
 		goto again;
 	}
 	/* HACK youth_next should always be at least 0x8000 so that
@@ -1119,12 +1116,12 @@ again:
 	if (fs->youth_next < 0x8000)
 		fs->youth_next = 0x8000;
 
-	if (db && test_bit(FinalCheckpoint, &fs->fsstate)) {
-		putdref(db, MKREF(youth));
-		db = NULL;
+	if (ssum && test_bit(FinalCheckpoint, &fs->fsstate)) {
+		ss_put(ssum, fs);
+		ssum = NULL;
 	}
 
-	if (db) {
+	if (ssum) {
 		u16 y = fs->youth_next;
 		if (fs->scan.do_decay &&
 		    (fs->scan.free_dev < ss->dev
@@ -1134,11 +1131,12 @@ again:
 			    ))
 			/* Haven't decayed this block yet - revert decay */
 			y = decay_undo(y);
-		youthp = map_dblock(db);
+		youthp = map_dblock(ssum->youthblk);
 		youthp[(*seg) & ((1 << (fs->blocksize_bits
 					- 1)) - 1)]
 			= cpu_to_le16(y);
-		unmap_dblock(db, youthp);
+		unmap_dblock(ssum->youthblk, youthp);
+		lafs_dirty_dblock(ssum->youthblk);
 	}
 	fs->youth_next++;
 
@@ -1161,20 +1159,15 @@ again:
 			/* ?? what do I need to release etc */
 			/* Maybe this cannot fail because we own references
 			 * to the two blocks !! */
-			LAFS_BUG(1, db ? &db->b : NULL);
+			LAFS_BUG(1, NULL);
 		lafs_checkpoint_lock(fs);
 		set_bit(B_PinPending, &ssum->ssblk->b.flags);
 		(void)lafs_pin_dblock(ssum->ssblk, AccountSpace);
-		if (ssnum == 0) {
-			set_bit(B_PinPending, &ssum->youthblk->b.flags);
-			(void)lafs_pin_dblock(ssum->youthblk, AccountSpace);
-		}
 		lafs_checkpoint_unlock(fs);
 	}
-	if (db) {
-		lafs_dirty_dblock(db);
-		putdref(db, MKREF(youth));
-	}
+	if (ssum)
+		ss_put(ssum, fs);
+
 	dprintk("NEXT segment found %d/%d youth %d\n",
 		*dev, *seg, fs->youth_next - 1);
 	/* Note that we return an implicit reference to the ssum */