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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: cmm@us.ibm.com, tytso@mit.edu, akpm@linux-foundation.org
Cc: linux-ext4@vger.kernel.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [Updated PATCH] ext4: Use the correct block number when reading the super block.
Date: Mon, 31 Dec 2007 13:59:22 +0530	[thread overview]
Message-ID: <1199089762-10378-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)

If the block device hard sector size is larger than EXT4_MIN_BLOCK_SIZE we
end up with wrong block number when reading super block.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/ext4/super.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1ca0f54..3095370 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1629,8 +1629,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	 * block sizes.  We need to calculate the offset from buffer start.
 	 */
 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
-		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
-		offset = do_div(logical_sb_block, blocksize);
+		logical_sb_block = (sb_block * EXT4_MIN_BLOCK_SIZE) / blocksize;
+		offset = do_div((sb_block * EXT4_MIN_BLOCK_SIZE), blocksize);
 	} else {
 		logical_sb_block = sb_block;
 	}
@@ -1747,8 +1747,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
 		brelse (bh);
 		sb_set_blocksize(sb, blocksize);
-		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
-		offset = do_div(logical_sb_block, blocksize);
+		logical_sb_block = (sb_block * EXT4_MIN_BLOCK_SIZE) / blocksize;
+		offset = do_div((sb_block * EXT4_MIN_BLOCK_SIZE), blocksize);
 		bh = sb_bread(sb, logical_sb_block);
 		if (!bh) {
 			printk(KERN_ERR
-- 
1.5.4.rc2-dirty

             reply	other threads:[~2007-12-31  8:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-31  8:29 Aneesh Kumar K.V [this message]
2007-12-31  8:42 ` [Updated PATCH] ext4: Use the correct block number when reading the super block Aneesh Kumar K.V

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