ocfs2: set gap to seperate entry and value when xattr in bucket

This patch set a gap (4 bytes) between xattr entry and
name/value when xattr in bucket. This gap use to seperate
entry and name/value when a bucket is full. It had already
been set when xattr in inode/block.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/xattr.c

@@ -82,13 +82,14 @@ struct ocfs2_xattr_set_ctxt {
 
 #define OCFS2_XATTR_ROOT_SIZE	(sizeof(struct ocfs2_xattr_def_value_root))
 #define OCFS2_XATTR_INLINE_SIZE	80
+#define OCFS2_XATTR_HEADER_GAP	4
 #define OCFS2_XATTR_FREE_IN_IBODY	(OCFS2_MIN_XATTR_INLINE_SIZE \
 					 - sizeof(struct ocfs2_xattr_header) \
-					 - sizeof(__u32))
+					 - OCFS2_XATTR_HEADER_GAP)
 #define OCFS2_XATTR_FREE_IN_BLOCK(ptr)	((ptr)->i_sb->s_blocksize \
 					 - sizeof(struct ocfs2_xattr_block) \
 					 - sizeof(struct ocfs2_xattr_header) \
-					 - sizeof(__u32))
+					 - OCFS2_XATTR_HEADER_GAP)
 
 static struct ocfs2_xattr_def_value_root def_xv = {
 	.xv.xr_list.l_count = cpu_to_le16(1),
@@ -1511,7 +1512,7 @@ static int ocfs2_xattr_set_entry(struct inode *inode,
 		last += 1;
 	}
 
-	free = min_offs - ((void *)last - xs->base) - sizeof(__u32);
+	free = min_offs - ((void *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
 	if (free < 0)
 		return -EIO;
 
@@ -2194,7 +2195,7 @@ static int ocfs2_xattr_can_be_in_inode(struct inode *inode,
 		last += 1;
 	}
 
-	free = min_offs - ((void *)last - xs->base) - sizeof(__u32);
+	free = min_offs - ((void *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
 	if (free < 0)
 		return 0;
 
@@ -5065,8 +5066,8 @@ try_again:
 	xh_free_start = le16_to_cpu(xh->xh_free_start);
 	header_size = sizeof(struct ocfs2_xattr_header) +
 			count * sizeof(struct ocfs2_xattr_entry);
-	max_free = OCFS2_XATTR_BUCKET_SIZE -
-		le16_to_cpu(xh->xh_name_value_len) - header_size;
+	max_free = OCFS2_XATTR_BUCKET_SIZE - header_size -
+		le16_to_cpu(xh->xh_name_value_len) - OCFS2_XATTR_HEADER_GAP;
 
 	mlog_bug_on_msg(header_size > blocksize, "bucket %llu has header size "
 			"of %u which exceed block size\n",
@@ -5099,7 +5100,7 @@ try_again:
 			need = 0;
 	}
 
-	free = xh_free_start - header_size;
+	free = xh_free_start - header_size - OCFS2_XATTR_HEADER_GAP;
 	/*
 	 * We need to make sure the new name/value pair
 	 * can exist in the same block.
@@ -5132,7 +5133,8 @@ try_again:
 			}
 
 			xh_free_start = le16_to_cpu(xh->xh_free_start);
-			free = xh_free_start - header_size;
+			free = xh_free_start - header_size
+				- OCFS2_XATTR_HEADER_GAP;
 			if (xh_free_start % blocksize < need)
 				free -= xh_free_start % blocksize;