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>,
Amir Goldstein <amir73il@gmail.com>,
Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
Joel Becker <jlbec@evilplan.org>,
linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 34/37] libext2fs: Calculate and verify superblock checksums
Date: Wed, 31 Aug 2011 17:38:49 -0700 [thread overview]
Message-ID: <20110901003849.1176.83693.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20110901003509.1176.51159.stgit@elm3c44.beaverton.ibm.com>
Calculate and verify the superblock checksums. Each copy of the superblock
records the number of the group it's in and the FS UUID, so we can simply
checksum the whole block.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
lib/ext2fs/closefs.c | 13 ++++++-------
lib/ext2fs/csum.c | 39 +++++++++++++++++++++++++++++++++++++++
lib/ext2fs/ext2_err.et.in | 3 +++
lib/ext2fs/ext2_fs.h | 3 ++-
lib/ext2fs/ext2fs.h | 6 ++++++
lib/ext2fs/openfs.c | 6 ++++++
lib/ext2fs/swapfs.c | 2 ++
7 files changed, 64 insertions(+), 8 deletions(-)
diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c
index 73dc136..017e9ba 100644
--- a/lib/ext2fs/closefs.c
+++ b/lib/ext2fs/closefs.c
@@ -256,10 +256,11 @@ static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
if (sgrp > ((1 << 16) - 1))
sgrp = (1 << 16) - 1;
+
+ super_shadow->s_block_group_nr = sgrp;
+ ext2fs_superblock_csum_set(fs, super_shadow);
#ifdef WORDS_BIGENDIAN
- super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
-#else
- fs->super->s_block_group_nr = sgrp;
+ ext2fs_swap_super(super_shadow);
#endif
return io_channel_write_blk64(fs->io, group_block, -SUPERBLOCK_SIZE,
@@ -315,6 +316,7 @@ errcode_t ext2fs_flush(ext2_filsys fs)
&group_shadow);
if (retval)
goto errout;
+ memcpy(super_shadow, fs->super, sizeof(struct ext2_super_block));
memcpy(group_shadow, fs->group_desc, (size_t) fs->blocksize *
fs->desc_blocks);
@@ -335,10 +337,6 @@ errcode_t ext2fs_flush(ext2_filsys fs)
*/
fs->super->s_state &= ~EXT2_VALID_FS;
fs->super->s_feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
-#ifdef WORDS_BIGENDIAN
- *super_shadow = *fs->super;
- ext2fs_swap_super(super_shadow);
-#endif
/*
* If this is an external journal device, don't write out the
@@ -408,6 +406,7 @@ write_primary_superblock_only:
fs->super->s_block_group_nr = 0;
fs->super->s_state = fs_state;
fs->super->s_feature_incompat = feature_incompat;
+ ext2fs_superblock_csum_set(fs, fs->super);
#ifdef WORDS_BIGENDIAN
*super_shadow = *fs->super;
ext2fs_swap_super(super_shadow);
diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index dc87de3..1da5bfc 100644
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -29,6 +29,45 @@
#define STATIC static
#endif
+__u32 ext2fs_superblock_csum(ext2_filsys fs, struct ext2_super_block *sb)
+{
+ int offset = offsetof(struct ext2_super_block, s_checksum);
+ __u32 crc = 0;
+
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 0;
+
+#ifdef WORDS_BIGENDIAN
+ struct ext2_super_block swabsb;
+ memcpy(&swabsb, sb, sizeof(struct ext2_super_block));
+ ext2fs_swap_super(&swabsb);
+ sb = &swabsb;
+#endif
+
+ crc = crc32c_le(~0, (char *)sb, offset);
+
+ return crc;
+}
+
+int ext2fs_superblock_csum_verify(ext2_filsys fs, struct ext2_super_block *sb)
+{
+ if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+ (sb->s_checksum != ext2fs_superblock_csum(fs, sb)))
+ return 0;
+ return 1;
+}
+
+void ext2fs_superblock_csum_set(ext2_filsys fs, struct ext2_super_block *sb)
+{
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ sb->s_checksum = ext2fs_superblock_csum(fs, sb);
+}
+
__u32 ext2fs_ext_attr_block_csum(ext2_filsys fs, blk64_t block,
struct ext2_ext_attr_header *hdr)
{
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index 6e2c22c..956427d 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -434,4 +434,7 @@ ec EXT2_ET_INODE_CSUM_NONZERO,
ec EXT2_ET_EXT_ATTR_BLOCK_CORRUPT,
"Extended attribute block fails checksum"
+ec EXT2_ET_SB_CSUM_INVALID,
+ "Superblock fails checksum"
+
end
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index 40b5900..7d43e15 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -589,7 +589,8 @@ struct ext2_super_block {
__u32 s_usr_quota_inum; /* inode number of user quota file */
__u32 s_grp_quota_inum; /* inode number of group quota file */
__u32 s_overhead_blocks; /* overhead blocks/clusters in fs */
- __u32 s_reserved[109]; /* Padding to the end of the block */
+ __u32 s_checksum; /* crc32c(superblock) */
+ __u32 s_reserved[108]; /* Padding to the end of the block */
};
#define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 0820e43..282806b 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -894,6 +894,12 @@ extern __u32 crc32c_be(__u32 crc, unsigned char const *p, size_t len);
extern __u32 crc32c_le(__u32 crc, unsigned char const *p, size_t len);
/* csum.c */
+extern __u32 ext2fs_superblock_csum(ext2_filsys fs,
+ struct ext2_super_block *sb);
+extern int ext2fs_superblock_csum_verify(ext2_filsys fs,
+ struct ext2_super_block *sb);
+extern void ext2fs_superblock_csum_set(ext2_filsys fs,
+ struct ext2_super_block *sb);
extern __u32 ext2fs_ext_attr_block_csum(ext2_filsys fs, blk64_t block,
struct ext2_ext_attr_header *hdr);
extern int ext2fs_ext_attr_block_csum_verify(ext2_filsys fs, blk64_t block,
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index 0edeb2f..5472d9a 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -198,6 +198,12 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
}
#endif
+ if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_superblock_csum_verify(fs, fs->super)) {
+ retval = EXT2_ET_SB_CSUM_INVALID;
+ goto cleanup;
+ }
+
if (fs->super->s_magic != EXT2_SUPER_MAGIC) {
retval = EXT2_ET_BAD_MAGIC;
goto cleanup;
diff --git a/lib/ext2fs/swapfs.c b/lib/ext2fs/swapfs.c
index 5cbb4b9..5234451 100644
--- a/lib/ext2fs/swapfs.c
+++ b/lib/ext2fs/swapfs.c
@@ -94,6 +94,8 @@ void ext2fs_swap_super(struct ext2_super_block * sb)
}
for (; i < 17; i++)
sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
+
+ sb->s_checksum = ext2fs_swab32(sb->s_checksum);
}
void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
next prev parent reply other threads:[~2011-09-01 0:38 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 0:35 [PATCH v1 00/37] e2fsprogs: Add metadata checksumming Darrick J. Wong
2011-09-01 0:35 ` [PATCH 01/37] e2fsprogs: Read and write full-sized inodes Darrick J. Wong
2011-09-03 18:05 ` Andreas Dilger
2011-09-04 14:04 ` Ted Ts'o
2011-09-04 17:40 ` Andreas Dilger
2011-09-14 16:39 ` Ted Ts'o
2011-09-15 20:25 ` Darrick J. Wong
2011-09-15 21:35 ` Andreas Dilger
2011-09-16 1:04 ` Darrick J. Wong
2011-09-18 1:52 ` Ted Ts'o
2011-09-01 0:35 ` [PATCH 02/37] libext2fs: Add metadata checksum flag Darrick J. Wong
2011-09-04 1:47 ` Andreas Dilger
2011-09-01 0:35 ` [PATCH 03/37] debugfs: Optionally ignore bad checksums Darrick J. Wong
2011-09-01 0:35 ` [PATCH 04/37] libext2fs: Add crc32c implementation for metadata checksumming Darrick J. Wong
2011-09-16 3:32 ` Ted Ts'o
2011-09-01 0:35 ` [PATCH 05/37] libext2fs: Implement a crc32c self-test Darrick J. Wong
2011-09-01 0:35 ` [PATCH 06/37] libext2fs: Add inode checksum support Darrick J. Wong
2011-09-04 17:59 ` Andreas Dilger
2011-09-05 18:59 ` Darrick J. Wong
2011-09-01 0:35 ` [PATCH 07/37] debugfs: Dump inode checksum when appropriate Darrick J. Wong
2011-09-01 0:36 ` [PATCH 08/37] tune2fs: Add inode checksum support Darrick J. Wong
2011-09-01 0:36 ` [PATCH 09/37] e2fsck: Verify and correct inode checksums Darrick J. Wong
2011-09-04 18:17 ` Andreas Dilger
2011-09-05 19:05 ` Darrick J. Wong
2011-09-01 0:36 ` [PATCH 10/37] mke2fs: Allow metadata checksums to be turned on at mkfs time Darrick J. Wong
2011-09-04 18:28 ` Andreas Dilger
2011-09-05 19:20 ` Darrick J. Wong
2011-09-06 1:54 ` Andreas Dilger
2011-09-06 17:13 ` Darrick J. Wong
2011-09-01 0:36 ` [PATCH 11/37] libext2fs: Create the inode bitmap checksum Darrick J. Wong
2011-09-14 17:02 ` Ted Ts'o
2011-09-14 19:31 ` Darrick J. Wong
2011-09-14 20:00 ` Andreas Dilger
2011-09-14 19:59 ` Andreas Dilger
2011-09-14 22:14 ` Ted Ts'o
2011-09-01 0:36 ` [PATCH 12/37] tune2fs: Rewrite inode bitmap checksums Darrick J. Wong
2011-09-01 0:36 ` [PATCH 13/37] dumpe2fs: Display inode bitmap checksum Darrick J. Wong
2011-09-04 18:30 ` Andreas Dilger
2011-09-05 19:20 ` Darrick J. Wong
2011-09-01 0:36 ` [PATCH 14/37] e2fsck: Verify " Darrick J. Wong
2011-09-01 0:36 ` [PATCH 15/37] libext2fs: Create the block " Darrick J. Wong
2011-09-01 0:36 ` [PATCH 16/37] dumpe2fs: Display " Darrick J. Wong
2011-09-01 0:37 ` [PATCH 17/37] e2fsck: Verify " Darrick J. Wong
2011-09-01 0:37 ` [PATCH 18/37] e2fsck: Don't verify bitmap checksums Darrick J. Wong
2011-09-01 0:37 ` [PATCH 19/37] tune2fs: Rewrite block " Darrick J. Wong
2011-09-01 0:37 ` [PATCH 20/37] libext2fs: Verify and calculate extent tree block checksums Darrick J. Wong
2011-09-01 0:37 ` [PATCH 21/37] tune2fs: Enable extent tree checksums Darrick J. Wong
2011-09-01 0:37 ` [PATCH 22/37] libext2fs: Introduce dx_tail and dir_entry_tail Darrick J. Wong
2011-09-01 0:37 ` [PATCH 23/37] debugfs: Print htree internal node checksums Darrick J. Wong
2011-09-01 0:37 ` [PATCH 24/37] libext2fs: Add dx_root/dx_node checksum calculation and verification helpers Darrick J. Wong
2011-09-01 0:37 ` [PATCH 25/37] e2fsck: Verify htree root/node checksums Darrick J. Wong
2011-09-01 0:37 ` [PATCH 26/37] libext2fs: Introduce dir_entry_tail to provide checksums for directory leaf nodes Darrick J. Wong
2011-09-01 0:38 ` [PATCH 27/37] e2fsck: Check directory leaf block checksums Darrick J. Wong
2011-09-01 0:38 ` [PATCH 28/37] tune2fs: Rebuild and checksum directories when toggling metadata_csum or changing UUID Darrick J. Wong
2011-09-01 0:38 ` [PATCH 29/37] libext2fs: Verify and calculate extended attribute block checksums Darrick J. Wong
2011-09-01 0:38 ` [PATCH 30/37] e2fsck: Check " Darrick J. Wong
2011-09-01 0:38 ` [PATCH 32/37] libext2fs: Extend inode checksum to cover the EA block Darrick J. Wong
2011-09-14 16:48 ` Ted Ts'o
2011-09-01 0:38 ` [PATCH 33/37] tune2fs: Rewrite extended attribute block checksums Darrick J. Wong
2011-09-01 0:38 ` Darrick J. Wong [this message]
2011-09-01 0:38 ` [PATCH 35/37] e2fsck: Handle superblock checksum errors gracefully Darrick J. Wong
2011-09-01 0:39 ` [PATCH 36/37] e2p: Print superblock checksum in list_super Darrick J. Wong
2011-09-01 0:39 ` [PATCH 37/37] e2fsck: Support CRC32c checksum in journal commit blocks Darrick J. Wong
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