From: Steven Whitehouse <swhiteho@redhat.com>
Subject: [RHEL5] Fix up gfs2 dirent format to make it compatible with gfs1
Date: Tue, 12 Dec 2006 11:12:17 +0000
Bugzilla: 219266
Message-Id: <1165921937.3752.1086.camel@quoit.chygwyn.com>
Changelog: gfs2: dirent format compatible with gfs1


Hi,

Here is the patch from upstream which fixes bz #219266. The bz referred
to below are actually the userland part of the fix. It is harmless in
that the only effect is to generate warnings from fsck, but we might as
well fix it up anyway so that its 100% correct from now on,

Steve.

>From 5e7d65cd9d3819512b059f4260de0119b985454c Mon Sep 17 00:00:00 2001

When deleting directory entries, we set the inum.no_addr to zero
in a dirent when its the first dirent in a block and thus cannot
be merged into the previous dirent as is the usual case. In gfs1,
inum.no_formal_ino was used instead.

This patch changes gfs2 to set both inum.no_addr and inum.no_formal_ino
to zero. It also changes the test from just looking at inum.no_addr to
look at both inum.no_addr and inum.no_formal_ino and a sentinel is
now considered to be a dirent in which _either_ (or both) of them
is set to zero.

This resolves Red Hat bugzillas: #215809, #211465

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
 fs/gfs2/dir.c |   26 ++++++++++++++++----------
 1 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index a2923fb..0fdcb77 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -340,10 +340,15 @@ fail:
 	return (copied) ? copied : error;
 }
 
+static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
+{
+	return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
+}
+
 static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
 				     const struct qstr *name, int ret)
 {
-	if (dent->de_inum.no_addr != 0 &&
+	if (!gfs2_dirent_sentinel(dent) &&
 	    be32_to_cpu(dent->de_hash) == name->hash &&
 	    be16_to_cpu(dent->de_name_len) == name->len &&
 	    memcmp(dent+1, name->name, name->len) == 0)
@@ -388,7 +393,7 @@ static int gfs2_dirent_find_space(const 
 	unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 	unsigned totlen = be16_to_cpu(dent->de_rec_len);
 
-	if (!dent->de_inum.no_addr)
+	if (gfs2_dirent_sentinel(dent))
 		actual = GFS2_DIRENT_SIZE(0);
 	if (totlen - actual >= required)
 		return 1;
@@ -405,7 +410,7 @@ static int gfs2_dirent_gather(const stru
 			      void *opaque)
 {
 	struct dirent_gather *g = opaque;
-	if (dent->de_inum.no_addr) {
+	if (!gfs2_dirent_sentinel(dent)) {
 		g->pdent[g->offset++] = dent;
 	}
 	return 0;
@@ -433,10 +438,10 @@ static int gfs2_check_dirent(struct gfs2
 	if (unlikely(offset + size > len))
 		goto error;
 	msg = "zero inode number";
-	if (unlikely(!first && !dent->de_inum.no_addr))
+	if (unlikely(!first && gfs2_dirent_sentinel(dent)))
 		goto error;
 	msg = "name length is greater than space in dirent";
-	if (dent->de_inum.no_addr &&
+	if (!gfs2_dirent_sentinel(dent) &&
 	    unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
 		     size))
 		goto error;
@@ -598,7 +603,7 @@ static int dirent_next(struct gfs2_inode
 		return ret;
 
         /* Only the first dent could ever have de_inum.no_addr == 0 */
-	if (!tmp->de_inum.no_addr) {
+	if (gfs2_dirent_sentinel(tmp)) {
 		gfs2_consist_inode(dip);
 		return -EIO;
 	}
@@ -621,7 +626,7 @@ static void dirent_del(struct gfs2_inode
 {
 	u16 cur_rec_len, prev_rec_len;
 
-	if (!cur->de_inum.no_addr) {
+	if (gfs2_dirent_sentinel(cur)) {
 		gfs2_consist_inode(dip);
 		return;
 	}
@@ -633,7 +638,8 @@ static void dirent_del(struct gfs2_inode
 	   out the inode number and return.  */
 
 	if (!prev) {
-		cur->de_inum.no_addr = 0;	/* No endianess worries */
+		cur->de_inum.no_addr = 0;
+		cur->de_inum.no_formal_ino = 0;
 		return;
 	}
 
@@ -664,7 +670,7 @@ static struct gfs2_dirent *gfs2_init_dir
 	struct gfs2_dirent *ndent;
 	unsigned offset = 0, totlen;
 
-	if (dent->de_inum.no_addr)
+	if (!gfs2_dirent_sentinel(dent))
 		offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
 	totlen = be16_to_cpu(dent->de_rec_len);
 	BUG_ON(offset + name->len > totlen);
@@ -1002,7 +1008,7 @@ static int dir_split_leaf(struct inode *
 		if (dirent_next(dip, obh, &next))
 			next = NULL;
 
-		if (dent->de_inum.no_addr &&
+		if (!gfs2_dirent_sentinel(dent) &&
 		    be32_to_cpu(dent->de_hash) < divider) {
 			struct qstr str;
 			str.name = (char*)(dent+1);
-- 
1.4.1