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Date: Wed, 31 Aug 2011 17:35:49 -0700
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>,
Amir Goldstein <amir73il@...il.com>,
Andi Kleen <andi@...stfloor.org>,
Mingming Cao <cmm@...ibm.com>,
Joel Becker <jlbec@...lplan.org>, linux-ext4@...r.kernel.org,
Coly Li <colyli@...il.com>
Subject: [PATCH 06/37] libext2fs: Add inode checksum support
This patch adds the ability for the libext2fs functions to read and write the
inode checksum. It also fixes a few fields that were omitted from the byte
swapping routines.
Signed-off-by: Darrick J. Wong <djwong@...ibm.com>
---
lib/ext2fs/csum.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
lib/ext2fs/ext2_err.et.in | 9 +++++++
lib/ext2fs/ext2_fs.h | 4 ++-
lib/ext2fs/ext2fs.h | 6 +++++
lib/ext2fs/inode.c | 20 +++++++++++++++
lib/ext2fs/swapfs.c | 10 ++++++--
6 files changed, 104 insertions(+), 4 deletions(-)
diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index 2fece68..57adc4c 100644
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -29,6 +29,65 @@
#define STATIC static
#endif
+__u32 ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode)
+{
+ struct ext2_inode_large *desc = inode;
+ int offset = offsetof(struct ext2_inode_large, i_checksum);
+ int extra_size = inode->i_extra_isize;
+ size_t size = fs->super->s_inode_size;
+ __u32 crc = 0;
+
+ if (size < EXT2_GOOD_OLD_INODE_SIZE + extra_size)
+ printf("ERROR: inode %d size %d != extra_size %d!\n", inum,
+ size, extra_size + EXT2_GOOD_OLD_INODE_SIZE);
+
+ if (fs->super->s_creator_os != EXT2_OS_LINUX)
+ return 0;
+
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+
+ return 0;
+
+#ifdef WORDS_BIGENDIAN
+ char buf[EXT2_INODE_CORE_SIZE(fs->super)];
+ struct ext2_inode_large *swabinode = (struct ext2_inode_large *)buf;
+
+ /* Have to swab back to little-endian to do the checksum */
+ memcpy(swabinode, inode, size);
+ ext2fs_swap_inode_full(fs, swabinode, swabinode, 1, size);
+ desc = swabinode;
+#endif
+ inum = ext2fs_cpu_to_le32(inum);
+ crc = crc32c_le(~0, fs->super->s_uuid, sizeof(fs->super->s_uuid));
+ crc = crc32c_le(crc, (char *)&inum, sizeof(inum));
+ crc = crc32c_le(crc, (char *)desc, offset);
+ offset += sizeof(inode->i_checksum); /* skip checksum */
+ crc = crc32c_le(crc, (char *)desc + offset,
+ EXT2_GOOD_OLD_INODE_SIZE + extra_size - offset);
+ return crc;
+}
+
+int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode)
+{
+ if (fs->super->s_creator_os == EXT2_OS_LINUX &&
+ EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+ (inode->i_checksum != ext2fs_inode_csum(fs, inum, inode)))
+ return 0;
+ return 1;
+}
+
+void ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode)
+{
+ if (fs->super->s_creator_os != EXT2_OS_LINUX)
+ return;
+ inode->i_checksum = ext2fs_inode_csum(fs, inum, inode);
+}
+
STATIC __u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
{
__u16 crc = 0;
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index 995ddc3..31c8fe1 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -422,4 +422,13 @@ ec EXT2_NO_MTAB_FILE,
ec EXT2_ET_CANT_USE_LEGACY_BITMAPS,
"Filesystem too large to use legacy bitmaps"
+ec EXT2_ET_INODE_CSUM_INVALID,
+ "Inode checksum is incorrect"
+
+ec EXT2_ET_INODE_CORRUPT,
+ "Inode checksum indicates corruption"
+
+ec EXT2_ET_INODE_CSUM_NONZERO,
+ "Inode checksum should not be set"
+
end
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index ae7662e..1f08673 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -362,7 +362,7 @@ struct ext2_inode_large {
__u16 l_i_file_acl_high;
__u16 l_i_uid_high; /* these 2 fields */
__u16 l_i_gid_high; /* were reserved2[0] */
- __u32 l_i_reserved2;
+ __u32 l_i_checksum; /* crc32c(uuid+inum+inode) */
} linux2;
struct {
__u8 h_i_frag; /* Fragment number */
@@ -393,7 +393,7 @@ struct ext2_inode_large {
#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 osd2.linux2.l_i_checksum
#else
#if defined(__GNU__)
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index e571508..db8b28b 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -892,6 +892,12 @@ 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_inode_csum(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode);
+extern void ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode);
+extern int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+ struct ext2_inode_large *inode);
extern void ext2fs_group_desc_csum_set(ext2_filsys fs, dgrp_t group);
extern int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group);
extern errcode_t ext2fs_set_gdt_csum(ext2_filsys fs);
diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c
index 76893fd..0789505 100644
--- a/lib/ext2fs/inode.c
+++ b/lib/ext2fs/inode.c
@@ -509,6 +509,12 @@ errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
if (EXT2_INODE_SIZE(scan->fs->super) == EXT2_GOOD_OLD_INODE_SIZE)
inode->i_extra_isize = 0;
+ /* Verify the inode checksum. */
+ if (!(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_inode_csum_verify(scan->fs, scan->current_inode, inode))
+ return EXT2_ET_INODE_CSUM_INVALID;
+
+
scan->inodes_left--;
scan->current_inode++;
*ino = scan->current_inode;
@@ -617,6 +623,10 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
(struct ext2_inode_large *) inode,
0, bufsize);
#endif
+ /* Verify the inode checksum. */
+ if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_inode_csum_verify(fs, ino, inode))
+ return EXT2_ET_INODE_CSUM_INVALID;
/* Update the inode cache */
fs->icache->cache_last = (fs->icache->cache_last + 1) %
@@ -685,6 +695,16 @@ errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
w_inode = &temp_inode;
memset(w_inode, 0, length);
+ /*
+ * If inode checksum enabled, ensure that we actually have the whole
+ * inode in memory.
+ */
+ if (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE &&
+ bufsize <= EXT2_GOOD_OLD_INODE_SIZE) {
+ fprintf(stderr, "inode %d has a too-short buffer!\n", ino);
+ abort();
+ }
+ ext2fs_inode_csum_set(fs, ino, inode);
#ifdef WORDS_BIGENDIAN
ext2fs_swap_inode_full(fs, w_inode, inode, 1, bufsize);
#else
diff --git a/lib/ext2fs/swapfs.c b/lib/ext2fs/swapfs.c
index 517f1d7..df604ba 100644
--- a/lib/ext2fs/swapfs.c
+++ b/lib/ext2fs/swapfs.c
@@ -244,8 +244,7 @@ void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
t->osd2.linux2.l_i_gid_high =
ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
- t->osd2.linux2.l_i_reserved2 =
- ext2fs_swab32(f->osd2.linux2.l_i_reserved2);
+ t->i_checksum = ext2fs_swab32(f->i_checksum);
break;
case EXT2_OS_HURD:
t->osd1.hurd1.h_i_translator =
@@ -279,6 +278,13 @@ void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
return;
}
+ t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
+ t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
+ t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
+ t->i_crtime = ext2fs_swab32(f->i_crtime);
+ t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
+ t->i_version_hi = ext2fs_swab32(f->i_version_hi);
+
i = EXT2_GOOD_OLD_INODE_SIZE + extra_isize + sizeof(__u32);
if (bufsize < (int) i)
return; /* no space for EA magic */
--
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