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Date: Mon, 28 Nov 2011 15:26:56 -0800
From: "Darrick J. Wong" <djwong@...ibm.com>
To: Andreas Dilger <adilger.kernel@...ger.ca>,
Theodore Tso <tytso@....edu>,
"Darrick J. Wong" <djwong@...ibm.com>
Cc: Sunil Mushran <sunil.mushran@...cle.com>,
Martin K Petersen <martin.petersen@...cle.com>,
Greg Freemyer <greg.freemyer@...il.com>,
Amir Goldstein <amir73il@...il.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
Andi Kleen <andi@...stfloor.org>,
Mingming Cao <cmm@...ibm.com>,
Joel Becker <jlbec@...lplan.org>,
linux-fsdevel <linux-fsdevel@...r.kernel.org>,
linux-ext4@...r.kernel.org, Coly Li <colyli@...il.com>
Subject: [PATCH 06/22] ext4: Calculate and verify inode checksums
This patch introduces to ext4 the ability to calculate and verify inode
checksums. This requires the use of a new ro compatibility flag and some
accompanying e2fsprogs patches to provide the relevant features in tune2fs and
e2fsck. The inode generation changes have been integrated into this patch.
Signed-off-by: Darrick J. Wong <djwong@...ibm.com>
---
fs/ext4/ext4.h | 10 +++--
fs/ext4/ialloc.c | 13 ++++++
fs/ext4/inode.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++----
fs/ext4/ioctl.c | 7 +++
4 files changed, 130 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 4022320..6953d9f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -633,7 +633,8 @@ struct ext4_inode {
__le16 l_i_file_acl_high;
__le16 l_i_uid_high; /* these 2 fields */
__le16 l_i_gid_high; /* were reserved2[0] */
- __u32 l_i_reserved2;
+ __le16 l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
+ __le16 l_i_reserved;
} linux2;
struct {
__le16 h_i_reserved1; /* Obsoleted fragment number/size which are removed in ext4 */
@@ -649,7 +650,7 @@ struct ext4_inode {
} masix2;
} osd2; /* OS dependent 2 */
__le16 i_extra_isize;
- __le16 i_pad1;
+ __le16 i_checksum_hi; /* crc32c(uuid+inum+inode) BE */
__le32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
__le32 i_mtime_extra; /* extra Modification time(nsec << 2 | epoch) */
__le32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
@@ -751,7 +752,7 @@ do { \
#define i_gid_low i_gid
#define i_uid_high osd2.linux2.l_i_uid_high
#define i_gid_high osd2.linux2.l_i_gid_high
-#define i_reserved2 osd2.linux2.l_i_reserved2
+#define i_checksum_lo osd2.linux2.l_i_checksum_lo
#elif defined(__GNU__)
@@ -891,6 +892,9 @@ struct ext4_inode_info {
*/
tid_t i_sync_tid;
tid_t i_datasync_tid;
+
+ /* crc32c(uuid+inum) */
+ __u32 i_uuid_inum_csum;
};
/*
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 00beb4f..6151a68 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -892,6 +892,19 @@ got:
inode->i_generation = sbi->s_next_generation++;
spin_unlock(&sbi->s_next_gen_lock);
+ /* Precompute second piece of csum */
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ __u32 csum;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __le32 inum = cpu_to_le32(inode->i_ino);
+ __le32 gen = cpu_to_le32(inode->i_generation);
+ csum = ext4_chksum(sbi, sbi->s_uuid_csum, (__u8 *)&inum,
+ sizeof(inum));
+ ei->i_uuid_inum_csum = ext4_chksum(sbi, csum, (__u8 *)&gen,
+ sizeof(gen));
+ }
+
ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
ext4_set_inode_state(inode, EXT4_STATE_NEW);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 47eeabc..d11b7cb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -48,6 +48,73 @@
#define MPAGE_DA_EXTENT_TAIL 0x01
+static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __u16 csum_lo;
+ __u16 csum_hi = 0;
+ __u32 csum;
+
+ csum_lo = raw->i_checksum_lo;
+ raw->i_checksum_lo = 0;
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
+ csum_hi = raw->i_checksum_hi;
+ raw->i_checksum_hi = 0;
+ }
+
+ csum = ext4_chksum(sbi, ei->i_uuid_inum_csum, (__u8 *)raw,
+ EXT4_INODE_SIZE(inode->i_sb));
+
+ raw->i_checksum_lo = csum_lo;
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+ raw->i_checksum_hi = csum_hi;
+
+ return csum;
+}
+
+static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ __u32 provided, calculated;
+
+ if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+ cpu_to_le32(EXT4_OS_LINUX) ||
+ !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ provided = le16_to_cpu(raw->i_checksum_lo);
+ calculated = ext4_inode_csum(inode, raw, ei);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+ provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
+ else
+ calculated &= 0xFFFF;
+
+ return provided == calculated;
+}
+
+static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ __u32 csum;
+
+ if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+ cpu_to_le32(EXT4_OS_LINUX) ||
+ !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ csum = ext4_inode_csum(inode, raw, ei);
+ raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+ raw->i_checksum_hi = cpu_to_le16(csum >> 16);
+}
+
static inline int ext4_begin_ordered_truncate(struct inode *inode,
loff_t new_size)
{
@@ -3785,6 +3852,39 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
if (ret < 0)
goto bad_inode;
raw_inode = ext4_raw_inode(&iloc);
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
+ if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
+ EXT4_INODE_SIZE(inode->i_sb)) {
+ EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
+ EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
+ EXT4_INODE_SIZE(inode->i_sb));
+ ret = -EIO;
+ goto bad_inode;
+ }
+ } else
+ ei->i_extra_isize = 0;
+
+ /* Precompute second piece of csum */
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __u32 csum;
+ __le32 inum = cpu_to_le32(inode->i_ino);
+ __le32 gen = raw_inode->i_generation;
+ csum = ext4_chksum(sbi, sbi->s_uuid_csum, (__u8 *)&inum,
+ sizeof(inum));
+ ei->i_uuid_inum_csum = ext4_chksum(sbi, csum, (__u8 *)&gen,
+ sizeof(gen));
+ }
+
+ if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
+ EXT4_ERROR_INODE(inode, "checksum invalid");
+ ret = -EIO;
+ goto bad_inode;
+ }
+
inode->i_mode = le16_to_cpu(raw_inode->i_mode);
inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
@@ -3862,12 +3962,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
}
if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
- ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
- if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
- EXT4_INODE_SIZE(inode->i_sb)) {
- ret = -EIO;
- goto bad_inode;
- }
if (ei->i_extra_isize == 0) {
/* The extra space is currently unused. Use it. */
ei->i_extra_isize = sizeof(struct ext4_inode) -
@@ -3879,8 +3973,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
ext4_set_inode_state(inode, EXT4_STATE_XATTR);
}
- } else
- ei->i_extra_isize = 0;
+ }
EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
@@ -4105,6 +4198,8 @@ static int ext4_do_update_inode(handle_t *handle,
raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
}
+ ext4_inode_csum_set(inode, raw_inode, ei);
+
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
rc = ext4_handle_dirty_metadata(handle, NULL, bh);
if (!err)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a567968..4217f99 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -150,6 +150,13 @@ flags_out:
if (!inode_owner_or_capable(inode))
return -EPERM;
+ if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ ext4_warning(sb, "Setting inode version is not "
+ "supported with metadata_csum enabled.");
+ return -ENOTTY;
+ }
+
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
--
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