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 05/23] ext4: Calculate and verify superblock checksum
Date: Tue, 06 Mar 2012 12:48:28 -0800 [thread overview]
Message-ID: <20120306204828.1663.39312.stgit@elm3b70.beaverton.ibm.com> (raw)
In-Reply-To: <20120306204750.1663.96751.stgit@elm3b70.beaverton.ibm.com>
Calculate and verify the superblock checksum. Since the UUID and block group
number are embedded in each copy of the superblock, we need only checksum the
entire block. Refactor some of the code to eliminate open-coding of the
checksum update call.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/ext4/ext4.h | 10 ++++++++++
fs/ext4/ext4_jbd2.c | 9 ++++++++-
fs/ext4/ext4_jbd2.h | 7 +++++--
fs/ext4/inode.c | 3 +--
fs/ext4/namei.c | 4 ++--
fs/ext4/resize.c | 4 +++-
fs/ext4/super.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 76 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a4b2689..0f48aea 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1273,6 +1273,9 @@ struct ext4_sb_info {
/* Reference to checksum algorithm driver via cryptoapi */
struct crypto_shash *s_chksum_driver;
+
+ /* Precomputed FS UUID checksum for seeding other checksums */
+ __u32 s_csum_seed;
};
static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -1985,6 +1988,10 @@ extern int ext4_group_extend(struct super_block *sb,
extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
/* super.c */
+extern int ext4_superblock_csum_verify(struct super_block *sb,
+ struct ext4_super_block *es);
+extern void ext4_superblock_csum_set(struct super_block *sb,
+ struct ext4_super_block *es);
extern void *ext4_kvmalloc(size_t size, gfp_t flags);
extern void *ext4_kvzalloc(size_t size, gfp_t flags);
extern void ext4_kvfree(void *ptr);
@@ -2260,6 +2267,9 @@ static inline void ext4_unlock_group(struct super_block *sb,
static inline void ext4_mark_super_dirty(struct super_block *sb)
{
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+ ext4_superblock_csum_set(sb, es);
if (EXT4_SB(sb)->s_journal == NULL)
sb->s_dirt =1;
}
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index aca1790..90f7c2e 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -138,16 +138,23 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
}
int __ext4_handle_dirty_super(const char *where, unsigned int line,
- handle_t *handle, struct super_block *sb)
+ handle_t *handle, struct super_block *sb,
+ int now)
{
struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
int err = 0;
if (ext4_handle_valid(handle)) {
+ ext4_superblock_csum_set(sb,
+ (struct ext4_super_block *)bh->b_data);
err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
+ } else if (now) {
+ ext4_superblock_csum_set(sb,
+ (struct ext4_super_block *)bh->b_data);
+ mark_buffer_dirty(bh);
} else
sb->s_dirt = 1;
return err;
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 5802fa1..ed9b78d 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -141,7 +141,8 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
struct buffer_head *bh);
int __ext4_handle_dirty_super(const char *where, unsigned int line,
- handle_t *handle, struct super_block *sb);
+ handle_t *handle, struct super_block *sb,
+ int now);
#define ext4_journal_get_write_access(handle, bh) \
__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
@@ -153,8 +154,10 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line,
#define ext4_handle_dirty_metadata(handle, inode, bh) \
__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
(bh))
+#define ext4_handle_dirty_super_now(handle, sb) \
+ __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 1)
#define ext4_handle_dirty_super(handle, sb) \
- __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
+ __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 0)
handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index feaa82f..f3afe9c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3926,8 +3926,7 @@ static int ext4_do_update_inode(handle_t *handle,
EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
sb->s_dirt = 1;
ext4_handle_sync(handle);
- err = ext4_handle_dirty_metadata(handle, NULL,
- EXT4_SB(sb)->s_sbh);
+ err = ext4_handle_dirty_super_now(handle, sb);
}
}
raw_inode->i_generation = cpu_to_le32(inode->i_generation);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 8b56fdf..e62e517 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2021,7 +2021,7 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
/* Insert this inode at the head of the on-disk orphan list... */
NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
- err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+ err = ext4_handle_dirty_super_now(handle, sb);
rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
if (!err)
err = rc;
@@ -2094,7 +2094,7 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
if (err)
goto out_brelse;
sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
- err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
+ err = ext4_handle_dirty_super_now(handle, inode->i_sb);
} else {
struct ext4_iloc iloc2;
struct inode *i_prev =
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index c6898e1..20c0a54 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -796,7 +796,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
ext4_kvfree(o_group_desc);
le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
- err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+ err = ext4_handle_dirty_super_now(handle, sb);
if (err)
ext4_std_error(sb, err);
@@ -968,6 +968,8 @@ static void update_backups(struct super_block *sb,
goto exit_err;
}
+ ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
+
while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
struct buffer_head *bh;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cfd8aa3..9881e90 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -121,6 +121,38 @@ static int ext4_verify_csum_type(struct super_block *sb,
return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
}
+static __le32 ext4_superblock_csum(struct super_block *sb,
+ struct ext4_super_block *es)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int offset = offsetof(struct ext4_super_block, s_checksum);
+ __u32 csum;
+
+ csum = ext4_chksum(sbi, ~0, (char *)es, offset);
+
+ return cpu_to_le32(csum);
+}
+
+int ext4_superblock_csum_verify(struct super_block *sb,
+ struct ext4_super_block *es)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ return es->s_checksum == ext4_superblock_csum(sb, es);
+}
+
+void ext4_superblock_csum_set(struct super_block *sb,
+ struct ext4_super_block *es)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ es->s_checksum = ext4_superblock_csum(sb, es);
+}
+
void *ext4_kvmalloc(size_t size, gfp_t flags)
{
void *ret;
@@ -3210,6 +3242,20 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
}
}
+ /* Check superblock checksum */
+ if (!ext4_superblock_csum_verify(sb, es)) {
+ ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
+ "invalid superblock checksum. Run e2fsck?");
+ silent = 1;
+ goto cantfind_ext4;
+ }
+
+ /* Precompute checksum seed for all metadata */
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
+ sizeof(es->s_uuid));
+
/* Set defaults before we parse the mount options */
def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
set_opt(sb, INIT_INODE_TABLE);
@@ -4218,6 +4264,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
&EXT4_SB(sb)->s_freeinodes_counter));
sb->s_dirt = 0;
BUFFER_TRACE(sbh, "marking dirty");
+ ext4_superblock_csum_set(sb, es);
mark_buffer_dirty(sbh);
if (sync) {
error = sync_dirty_buffer(sbh);
next prev parent reply other threads:[~2012-03-06 20:48 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-06 20:47 [PATCH v3 00/23] ext4: Add metadata checksumming Darrick J. Wong
2012-03-06 20:48 ` [PATCH 01/23] ext4: Create a new BH_Verified flag to avoid unnecessary metadata validation Darrick J. Wong
2012-03-06 20:48 ` [PATCH 02/23] ext4: Change on-disk layout to support extended metadata checksumming Darrick J. Wong
2012-03-06 20:48 ` [PATCH 03/23] ext4: Record the checksum algorithm in use in the superblock Darrick J. Wong
2012-03-06 20:48 ` [PATCH 04/23] ext4: Only call out to crc32c if necessary Darrick J. Wong
2012-03-06 20:48 ` Darrick J. Wong [this message]
2012-04-27 20:05 ` [PATCH 05/23] ext4: Calculate and verify superblock checksum Ted Ts'o
2012-04-30 16:19 ` djwong
2012-03-06 20:48 ` [PATCH 06/23] ext4: Calculate and verify inode checksums Darrick J. Wong
2012-03-06 20:48 ` [PATCH 07/23] ext4: Calculate and verify checksums for inode bitmaps Darrick J. Wong
2012-03-06 20:48 ` [PATCH 08/23] ext4: Calculate and verify block bitmap checksum Darrick J. Wong
2012-03-06 20:48 ` [PATCH 09/23] ext4: Verify and calculate checksums for extent tree blocks Darrick J. Wong
2012-03-06 20:49 ` [PATCH 10/23] ext4: Calculate and verify checksums for htree nodes Darrick J. Wong
2012-03-06 20:49 ` [PATCH 11/23] ext4: Calculate and verify checksums of directory leaf blocks Darrick J. Wong
2012-03-06 20:49 ` [PATCH 12/23] ext4: Calculate and verify checksums of extended attribute blocks Darrick J. Wong
2012-03-06 20:49 ` [PATCH 13/23] ext4: Make block group checksums use metadata_csum algorithm Darrick J. Wong
2012-03-06 20:49 ` [PATCH 14/23] ext4: Add checksums to the MMP block Darrick J. Wong
2012-03-06 20:49 ` [PATCH 15/23] jbd2: Change disk layout for metadata checksumming Darrick J. Wong
2012-04-28 14:19 ` Ted Ts'o
2012-04-28 22:58 ` Andreas Dilger
2012-04-29 19:39 ` Ted Ts'o
2012-04-30 4:08 ` Andreas Dilger
2012-05-18 22:51 ` djwong
2012-04-30 15:53 ` djwong
2012-04-30 16:51 ` Andreas Dilger
2012-03-06 20:49 ` [PATCH 16/23] jbd2: Enable journal clients to enable v2 checksumming Darrick J. Wong
2012-03-06 20:49 ` [PATCH 17/23] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
2012-03-06 20:50 ` [PATCH 18/23] jbd2: Checksum journal superblock Darrick J. Wong
2012-03-06 20:50 ` [PATCH 19/23] jbd2: Checksum revocation blocks Darrick J. Wong
2012-03-06 20:50 ` [PATCH 20/23] jbd2: Checksum descriptor blocks Darrick J. Wong
2012-03-06 20:50 ` [PATCH 21/23] jbd2: Checksum commit blocks Darrick J. Wong
2012-03-06 20:50 ` [PATCH 22/23] jbd2: Checksum data blocks that are stored in the journal Darrick J. Wong
2012-03-06 20:50 ` [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 --
2012-01-07 8:27 [PATCH v2.3 00/23] ext4: Add metadata checksumming Darrick J. Wong
2012-01-07 8:28 ` [PATCH 05/23] ext4: Calculate and verify superblock checksum Darrick J. Wong
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