[Ocfs2-devel] [PATCH 14/17] ocfs2: Add ocfs2_gd_is_discontig.

[Tao Ma <tao.ma@oracle.com>]

Hi Joel,

Joel Becker wrote:
> On Thu, Apr 22, 2010 at 02:40:28PM +0800, Tao Ma wrote:
>> Add ocfs2_gd_is_discontig so that we can test whether
>> a group descriptor is discontiguous or not.
>>
>> Signed-off-by: Tao Ma <tao.ma@oracle.com>
>> ---
>>  fs/ocfs2/ocfs2_fs.h |    6 ++++++
>>  1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
>> index 67bb8a7..b5b3cb7 100644
>> --- a/fs/ocfs2/ocfs2_fs.h
>> +++ b/fs/ocfs2/ocfs2_fs.h
>> @@ -1574,5 +1574,11 @@ static inline void ocfs2_set_de_type(struct ocfs2_dir_entry *de,
>>  	de->file_type = ocfs2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
>>  }
>>  
>> +static inline int ocfs2_gd_is_discontig(struct ocfs2_group_desc *gd)
>> +{
>> +	return ((offsetof(struct ocfs2_group_desc, bg_bitmap) + gd->bg_size ==
>> +		offsetof(struct ocfs2_group_desc, bg_list)) &&
>> +		gd->bg_list.l_next_free_rec);
> 
> 	You're missing a paren around the addition:
> 
> 	return (((offsetof(struct ocfs2_group_desc, bg_bitmap) + gd->bg_size) ==
> 		 offsetof(struct ocfs2_group_desc, bg_list)) &&
> 		gd->bg_list.l_next_free_rec);
Actually '+' is more precedent than '=='. But yes, we have made a consensus
that we should use more paren to make it clear.
> 	
> 	Would this be more readable:
> 
> 	if ((offsetof(struct ocfs2_group_desc, bg_bitmap) + gd->bg_size) !=
> 	    offsetof(struct ocfs2_group_desc, bg_list))
> 		return 0;
> 	/*
> 	 * Only valid to check l_next_free_rec if 
> 	 * bg_bitmap + bg_size == bg_list
> 	 */
> 	if (!gd->bg_list.l_next_free_rec)
> 		return 0;
> 	return 1;
OK, I will use it. Here is the updated one.

Regards,
Tao

From 98733de3ad63dab2359d9643dda25e0fb4ddafc9 Mon Sep 17 00:00:00 2001
From: Tao Ma <tao.ma@oracle.com>
Date: Tue, 27 Apr 2010 08:30:28 +0800
Subject: [PATCH 14/17] ocfs2: Add ocfs2_gd_is_discontig.

Add ocfs2_gd_is_discontig so that we can test whether
a group descriptor is discontiguous or not.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
---
 fs/ocfs2/ocfs2_fs.h |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index 67bb8a7..5f54a76 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -1574,5 +1574,18 @@ static inline void ocfs2_set_de_type(struct ocfs2_dir_entry *de,
 	de->file_type = ocfs2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
 }
 
+static inline int ocfs2_gd_is_discontig(struct ocfs2_group_desc *gd)
+{
+	if ((offsetof(struct ocfs2_group_desc, bg_bitmap) + gd->bg_size) !=
+	    offsetof(struct ocfs2_group_desc, bg_list))
+		return 0;
+	/*
+	 * Only valid to check l_next_free_rec if
+	 * bg_bitmap + bg_size == bg_list.
+	 */
+	if (!gd->bg_list.l_next_free_rec)
+		return 0;
+	return 1;
+}
 #endif  /* _OCFS2_FS_H */
 
-- 
1.5.5