From: NeilBrown <neilb@suse.de>
Date: Mon, 7 Jun 2010 01:30:48 +0000 (+1000)
Subject: Make sure find_block loads data from inode.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=91f65e5fba56b16c4b1124f058a1d0870eaba6a6;p=LaFS.git

Make sure find_block loads data from inode.

lafs_load_block expects not to need to read block 0
of a depth==0 inode as lafs_find_block is expected to
load that.
However there is a case where find_block (called from lafs_find_block)
skips the load.  So remove that case.

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

diff --git a/index.c b/index.c
index 7512092..5d113ec 100644
--- a/index.c
+++ b/index.c
@@ -1692,28 +1692,27 @@ find_block(struct datablock *b, int adopt, int async)
 	LAFS_BUG(test_bit(B_Pinned, &b->b.flags) &&
 		 b->b.parent == NULL,
 		 &b->b);
-
-	if (test_bit(B_PhysValid, &b->b.flags)
-	    && (!adopt || b->b.parent || test_bit(B_Root, &b->b.flags))) {
-		return 0;
-	}
 	if (b->b.inode == NULL)
 		return 0;
 	lai = LAFSI(b->b.inode);
 
 	if (lai->depth == 0) {
 		/* Data is in the inode if anywhere */
-		b->b.physaddr = 0;
-		set_bit(B_PhysValid, &b->b.flags);
+		if (!test_bit(B_PhysValid, &b->b.flags)) {
+			b->b.physaddr = 0;
+			set_bit(B_PhysValid, &b->b.flags);
+		}
 		db = lafs_inode_dblock(b->b.inode, async, MKREF(findblock));
 		if (IS_ERR(db))
 			return PTR_ERR(db);
-		if (!test_bit(B_Valid, &b->b.flags) && b->b.fileaddr == 0)
+		if (!test_bit(B_Valid, &b->b.flags) && b->b.fileaddr == 0) {
 			/* Now is the best time to copy data from inode into
 			 * datablock, as we know we have a valid inode block
 			 * now.
 			 */
+			LAFS_BUG(b->b.physaddr != 0, &b->b);
 			fill_block_zero(b, db);
+		}
 		if (adopt) {
 			ib = lafs_make_iblock(b->b.inode, adopt, async,
 					      MKREF(findblock));
@@ -1726,6 +1725,12 @@ find_block(struct datablock *b, int adopt, int async)
 			putdref(db, MKREF(findblock));
 		return 0;
 	}
+
+	if (test_bit(B_PhysValid, &b->b.flags)
+	    && (!adopt || b->b.parent || test_bit(B_Root, &b->b.flags))) {
+		return 0;
+	}
+
 	db = lafs_inode_dblock(b->b.inode, async, MKREF(findblock));
 	if (IS_ERR(db))
 		return PTR_ERR(db);