[XFS] Fix attr2 corruption with btree data extents

SGI-PV: 958747
SGI-Modid: xfs-linux-melb:xfs-kern:27792a

Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Russell Cattelan <cattelan@thebarn.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 42 insertions, 3 deletions

diff --git a/fs/xfs/xfs_attr_leaf.c b/fs/xfs/xfs_attr_leaf.c
index cc4ffa413da..e4664136843 100644
--- a/fs/xfs/xfs_attr_leaf.c
+++ b/fs/xfs/xfs_attr_leaf.c
@@ -150,6 +150,7 @@ xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes)
 	int offset;
 	int minforkoff;	/* lower limit on valid forkoff locations */
 	int maxforkoff;	/* upper limit on valid forkoff locations */
+	int dsize;	
 	xfs_mount_t *mp = dp->i_mount;
 
 	offset = (XFS_LITINO(mp) - bytes) >> 3; /* rounded down */
@@ -169,8 +170,43 @@ xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes)
 		return 0;
 	}
 
-	/* data fork btree root can have at least this many key/ptr pairs */
-	minforkoff = MAX(dp->i_df.if_bytes, XFS_BMDR_SPACE_CALC(MINDBTPTRS));
+	dsize = dp->i_df.if_bytes;
+	
+	switch (dp->i_d.di_format) {
+	case XFS_DINODE_FMT_EXTENTS:
+		/* 
+		 * If there is no attr fork and the data fork is extents, 
+		 * determine if creating the default attr fork will result 
+		 * in the extents form migrating to btree. If so, the 
+		 * minimum offset only needs to be the space required for 
+		 * the btree root.
+		 */ 
+		if (!dp->i_d.di_forkoff && dp->i_df.if_bytes > mp->m_attroffset)
+			dsize = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
+		break;
+		
+	case XFS_DINODE_FMT_BTREE:
+		/*
+		 * If have data btree then keep forkoff if we have one,
+		 * otherwise we are adding a new attr, so then we set 
+		 * minforkoff to where the btree root can finish so we have 
+		 * plenty of room for attrs
+		 */
+		if (dp->i_d.di_forkoff) {
+			if (offset < dp->i_d.di_forkoff) 
+				return 0;
+			else 
+				return dp->i_d.di_forkoff;
+		} else
+			dsize = XFS_BMAP_BROOT_SPACE(dp->i_df.if_broot);
+		break;
+	}
+	
+	/* 
+	 * A data fork btree root must have space for at least 
+	 * MINDBTPTRS key/ptr pairs if the data fork is small or empty.
+	 */
+	minforkoff = MAX(dsize, XFS_BMDR_SPACE_CALC(MINDBTPTRS));
 	minforkoff = roundup(minforkoff, 8) >> 3;
 
 	/* attr fork btree root can have at least this many key/ptr pairs */
@@ -336,7 +372,8 @@ xfs_attr_shortform_remove(xfs_da_args_t *args)
 	 */
 	totsize -= size;
 	if (totsize == sizeof(xfs_attr_sf_hdr_t) && !args->addname &&
-	    (mp->m_flags & XFS_MOUNT_ATTR2)) {
+	    (mp->m_flags & XFS_MOUNT_ATTR2) && 
+	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE)) {
 		/*
 		 * Last attribute now removed, revert to original
 		 * inode format making all literal area available
@@ -748,6 +785,7 @@ xfs_attr_shortform_allfit(xfs_dabuf_t *bp, xfs_inode_t *dp)
 				+ be16_to_cpu(name_loc->valuelen);
 	}
 	if ((dp->i_mount->m_flags & XFS_MOUNT_ATTR2) &&
+	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
 	    (bytes == sizeof(struct xfs_attr_sf_hdr)))
 		return(-1);
 	return(xfs_attr_shortform_bytesfit(dp, bytes));
@@ -786,6 +824,7 @@ xfs_attr_leaf_to_shortform(xfs_dabuf_t *bp, xfs_da_args_t *args, int forkoff)
 
 	if (forkoff == -1) {
 		ASSERT(dp->i_mount->m_flags & XFS_MOUNT_ATTR2);
+		ASSERT(dp->i_d.di_format != XFS_DINODE_FMT_BTREE);
 
 		/*
 		 * Last attribute was removed, revert to original