Patchwork [06/37] libext2fs: Add inode checksum support

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Submitter Darrick J. Wong
Date Sept. 1, 2011, 12:35 a.m.
Message ID <20110901003549.1176.81379.stgit@elm3c44.beaverton.ibm.com>
Download mbox | patch
Permalink /patch/112753/
State Changes Requested
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Comments

Darrick J. Wong - Sept. 1, 2011, 12:35 a.m.
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@us.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(-)



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Andreas Dilger - Sept. 4, 2011, 5:59 p.m.
On 2011-08-31, at 6:35 PM, "Darrick J. Wong" <djwong@us.ibm.com> wrote:

> 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@us.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);

This shouldn't have to be checked for every inode checksum. If the checksum is covering the whole inode size then this is a constant size, and e2fsck is already checking the value of i_extra_isize. 

> +    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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Darrick J. Wong - Sept. 5, 2011, 6:59 p.m.
On Sun, Sep 04, 2011 at 11:59:44AM -0600, Andreas Dilger wrote:
> On 2011-08-31, at 6:35 PM, "Darrick J. Wong" <djwong@us.ibm.com> wrote:
> 
> > 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@us.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);
> 
> This shouldn't have to be checked for every inode checksum. If the checksum
> is covering the whole inode size then this is a constant size, and e2fsck is
> already checking the value of i_extra_isize. 

This actually comes out later in the patchset when I change the checksum to
cover the entire inode size.  I'll remove this hunk since it goes away.

--D
> 
> > +    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 */
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
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Patch

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 */