linux-ext4 - [PATCH][BUG][TAKE2] ext4: unify each meaning of the offset in ext4_check_dir

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Message-Id: <20100203161348.0bf98d58.toshi.okajima@jp.fujitsu.com>
Date:	Wed, 3 Feb 2010 16:13:48 +0900
From:	Toshiyuki Okajima <toshi.okajima@...fujitsu.com>
To:	tytso@....edu, adilger@....com
Cc:	linux-ext4@...r.kernel.org
Subject: [PATCH][BUG][TAKE2] ext4: unify each meaning of the offset in
 ext4_check_dir_entry calling from some functions.

From: Toshiyuki Okajima <toshi.okajima@...fujitsu.com>

"offset" of the error message of ext4_check_dir_entry() might change the
meaning by the caller. There are 2 meanings:
- "File offset"
  called by:
   ext4_readdir, htree_dirblock_to_tree, search_dirblock, ext4_dx_find_entry,
   empty_dir
- "Buffer offset"
  called by:
   add_dirent_to_buf, ext4_delete_entry

The best way to solve this problem is to change the meaning of
"Buffer offset" into "File offset" but it is not easy.
However, we can solve this problem easily if we unify the meanings into
"Buffer offset". So, instead of "File Offset" meaning, we add the block number
information to this message.

--- Examples ---
Original error message:
 EXT4-fs error (device loop0): htree_dirblock_to_tree: bad entry in directory \
 #12: rec_len is too small for name_len - offset=12288, inode=216, rec_len=12,\
  name_len=11

Error message which is changed by this patch:
 EXT4-fs error (device loop0): htree_dirblock_to_tree: bad entry in directory \
 #12: rec_len is too small for name_len - block=78, offset=0, inode=216, \
 rec_len=12, name_len=11

Signed-off-by: Toshiyuki Okajima <toshi.okajima@...fujitsu.com>
---
 fs/ext4/dir.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 9dc9316..65da7e5 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -84,9 +84,11 @@ int ext4_check_dir_entry(const char *function, struct inode *dir,
 
 	if (error_msg != NULL)
 		ext4_error(dir->i_sb, function,
-			"bad entry in directory #%lu: %s - "
+			"bad entry in directory #%lu: %s - block=%llu, "
 			"offset=%u, inode=%u, rec_len=%d, name_len=%d",
-			dir->i_ino, error_msg, offset,
+			dir->i_ino, error_msg, 
+			(unsigned long long)bh->b_blocknr, 
+			(unsigned)(offset%bh->b_size),
 			le32_to_cpu(de->inode),
 			rlen, de->name_len);
 	return error_msg == NULL ? 1 : 0;
-- 
1.5.5.6
--
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