From 37804376121de1a25fb582bdd8970f139c4d9685 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@redhat.com>
Date: Mon, 26 Aug 2013 14:13:30 +1000
Subject: XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length),
 file: fs/xfs/xfs_trans_buf.c, line: 568

The calculation doesn't take into account the size of the dir v3
header, so overestimates the hash entries in a node. This causes
directory buffer overruns when splitting and merging nodes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h
index 8cdc77b..b1f2679 100644
--- a/fs/xfs/xfs_da_btree.h
+++ b/fs/xfs/xfs_da_btree.h
@@ -133,12 +133,19 @@ extern void xfs_da3_node_hdr_to_disk(struct xfs_da_intnode *to,
 				     struct xfs_da3_icnode_hdr *from);
 
 static inline int
-xfs_da3_node_hdr_size(struct xfs_da_intnode *dap)
+__xfs_da3_node_hdr_size(bool v3)
 {
-	if (dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC))
+	if (v3)
 		return sizeof(struct xfs_da3_node_hdr);
 	return sizeof(struct xfs_da_node_hdr);
 }
+static inline int
+xfs_da3_node_hdr_size(struct xfs_da_intnode *dap)
+{
+	bool	v3 = dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC);
+
+	return __xfs_da3_node_hdr_size(v3);
+}
 
 static inline struct xfs_da_node_entry *
 xfs_da3_node_tree_p(struct xfs_da_intnode *dap)
diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index d3ff96c..edf203a 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -90,6 +90,9 @@ void
 xfs_dir_mount(
 	xfs_mount_t	*mp)
 {
+	int	nodehdr_size;
+
+
 	ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
 	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
 	       XFS_MAX_BLOCKSIZE);
@@ -98,12 +101,13 @@ xfs_dir_mount(
 	mp->m_dirdatablk = xfs_dir2_db_to_da(mp, XFS_DIR2_DATA_FIRSTDB(mp));
 	mp->m_dirleafblk = xfs_dir2_db_to_da(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
 	mp->m_dirfreeblk = xfs_dir2_db_to_da(mp, XFS_DIR2_FREE_FIRSTDB(mp));
-	mp->m_attr_node_ents =
-		(mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
-		(uint)sizeof(xfs_da_node_entry_t);
-	mp->m_dir_node_ents =
-		(mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
-		(uint)sizeof(xfs_da_node_entry_t);
+
+	nodehdr_size = __xfs_da3_node_hdr_size(xfs_sb_version_hascrc(&mp->m_sb));
+	mp->m_attr_node_ents = (mp->m_sb.sb_blocksize - nodehdr_size) /
+				(uint)sizeof(xfs_da_node_entry_t);
+	mp->m_dir_node_ents = (mp->m_dirblksize - nodehdr_size) /
+				(uint)sizeof(xfs_da_node_entry_t);
+
 	mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
 	if (xfs_sb_version_hasasciici(&mp->m_sb))
 		mp->m_dirnameops = &xfs_ascii_ci_nameops;
-- 
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