From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
Theodore Tso <tytso@mit.edu>,
"Darrick J. Wong" <djwong@us.ibm.com>
Cc: Sunil Mushran <sunil.mushran@oracle.com>,
Martin K Petersen <martin.petersen@oracle.com>,
Greg Freemyer <greg.freemyer@gmail.com>,
Amir Goldstein <amir73il@gmail.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
Joel Becker <jlbec@evilplan.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 14/23] ext4: Add checksums to the MMP block
Date: Sat, 07 Jan 2012 00:29:26 -0800 [thread overview]
Message-ID: <20120107082926.21970.91132.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20120107082751.21970.84856.stgit@elm3c44.beaverton.ibm.com>
Compute and verify a checksum for the MMP block.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/ext4/ext4.h | 3 +++
fs/ext4/mmp.c | 44 +++++++++++++++++++++++++++++++++++++++-----
2 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e24386f..325bae0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2378,6 +2378,9 @@ extern int ext4_bio_write_page(struct ext4_io_submit *io,
/* mmp.c */
extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
+extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
+extern int ext4_mmp_csum_verify(struct super_block *sb,
+ struct mmp_struct *mmp);
/* BH_Uninit flag: blocks are allocated but uninitialized on disk */
enum ext4_state_bits {
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 7ea4ba4..142e9d7 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -6,12 +6,45 @@
#include "ext4.h"
+/* Checksumming functions */
+static __u32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int offset = offsetof(struct mmp_struct, mmp_checksum);
+ __u32 csum;
+
+ csum = ext4_chksum(sbi, sbi->s_csum_seed, (char *)mmp, offset);
+
+ return cpu_to_le32(csum);
+}
+
+int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);
+}
+
+void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);
+}
+
/*
* Write the MMP block using WRITE_SYNC to try to get the block on-disk
* faster.
*/
-static int write_mmp_block(struct buffer_head *bh)
+static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
{
+ struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
+
+ ext4_mmp_csum_set(sb, mmp);
mark_buffer_dirty(bh);
lock_buffer(bh);
bh->b_end_io = end_buffer_write_sync;
@@ -59,7 +92,8 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
}
mmp = (struct mmp_struct *)((*bh)->b_data);
- if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)
+ if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC ||
+ !ext4_mmp_csum_verify(sb, mmp))
return -EINVAL;
return 0;
@@ -120,7 +154,7 @@ static int kmmpd(void *data)
mmp->mmp_time = cpu_to_le64(get_seconds());
last_update_time = jiffies;
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
/*
* Don't spew too many error messages. Print one every
* (s_mmp_update_interval * 60) seconds.
@@ -200,7 +234,7 @@ static int kmmpd(void *data)
mmp->mmp_seq = cpu_to_le32(EXT4_MMP_SEQ_CLEAN);
mmp->mmp_time = cpu_to_le64(get_seconds());
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
failed:
kfree(data);
@@ -299,7 +333,7 @@ skip:
seq = mmp_new_seq();
mmp->mmp_seq = cpu_to_le32(seq);
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
if (retval)
goto failed;
next prev parent reply other threads:[~2012-01-07 8:29 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-07 8:27 [PATCH v2.3 00/23] ext4: Add metadata checksumming Darrick J. Wong
2012-01-07 8:27 ` [PATCH 01/23] ext4: Create a new BH_Verified flag to avoid unnecessary metadata validation Darrick J. Wong
2012-01-07 8:28 ` [PATCH 02/23] ext4: Change on-disk layout to support extended metadata checksumming Darrick J. Wong
2012-01-07 8:28 ` [PATCH 03/23] ext4: Record the checksum algorithm in use in the superblock Darrick J. Wong
2012-01-07 8:28 ` [PATCH 04/23] ext4: Only call out to crc32c if necessary Darrick J. Wong
2012-01-07 8:28 ` [PATCH 05/23] ext4: Calculate and verify superblock checksum Darrick J. Wong
2012-01-07 8:28 ` [PATCH 06/23] ext4: Calculate and verify inode checksums Darrick J. Wong
2012-01-07 8:28 ` [PATCH 07/23] ext4: Calculate and verify checksums for inode bitmaps Darrick J. Wong
2012-01-07 8:28 ` [PATCH 08/23] ext4: Calculate and verify block bitmap checksum Darrick J. Wong
2012-01-07 8:28 ` [PATCH 09/23] ext4: Verify and calculate checksums for extent tree blocks Darrick J. Wong
2012-01-07 8:28 ` [PATCH 10/23] ext4: Calculate and verify checksums for htree nodes Darrick J. Wong
2012-01-07 8:29 ` [PATCH 11/23] ext4: Calculate and verify checksums of directory leaf blocks Darrick J. Wong
2012-01-07 8:29 ` [PATCH 12/23] ext4: Calculate and verify checksums of extended attribute blocks Darrick J. Wong
2012-01-07 8:29 ` [PATCH 13/23] ext4: Add new feature to make block group checksums use metadata_csum algorithm Darrick J. Wong
[not found] ` <8ED6E1F9-DB56-4D31-BCA8-2A3A8D514BD5@dilger.ca>
2012-02-13 22:28 ` Ted Ts'o
2012-02-29 1:27 ` [RFC] e2fsprogs: Rework metadata_csum/gdt_csum flag handling Darrick J. Wong
2012-02-29 5:40 ` Andreas Dilger
2012-03-03 3:50 ` [RFC v2] " Darrick J. Wong
2012-02-29 1:32 ` [RFC] ext4: Rework metadata_csum/gdt_csum flag handling in kernel Darrick J. Wong
2012-02-29 5:48 ` Andreas Dilger
2012-03-03 3:56 ` [RFC v2] " Darrick J. Wong
2012-01-07 8:29 ` Darrick J. Wong [this message]
2012-01-07 8:29 ` [PATCH 15/23] jbd2: Change disk layout for metadata checksumming Darrick J. Wong
2012-01-07 8:29 ` [PATCH 16/23] jbd2: Enable journal clients to enable v2 checksumming Darrick J. Wong
2012-01-07 8:29 ` [PATCH 17/23] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
2012-01-07 8:29 ` [PATCH 18/23] jbd2: Checksum journal superblock Darrick J. Wong
2012-01-07 8:30 ` [PATCH 19/23] jbd2: Checksum revocation blocks Darrick J. Wong
2012-01-07 8:30 ` [PATCH 20/23] jbd2: Checksum descriptor blocks Darrick J. Wong
2012-01-07 8:30 ` [PATCH 21/23] jbd2: Checksum commit blocks Darrick J. Wong
2012-01-07 8:30 ` [PATCH 22/23] jbd2: Checksum data blocks that are stored in the journal Darrick J. Wong
2012-01-07 8:30 ` [PATCH 23/23] ext4/jbd2: Add metadata checksumming to the list of supported features Darrick J. Wong
-- strict thread matches above, loose matches on Subject: below --
2012-03-06 20:47 [PATCH v3 00/23] ext4: Add metadata checksumming Darrick J. Wong
2012-03-06 20:49 ` [PATCH 14/23] ext4: Add checksums to the MMP block Darrick J. Wong
2011-12-14 0:46 [PATCH v2.2 00/23] ext4: Add metadata checksumming Darrick J. Wong
2011-12-14 0:47 ` [PATCH 14/23] ext4: Add checksums to the MMP block Darrick J. Wong
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