On Mon, Oct 09, 2017 at 10:54:11AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Prevent kmemcheck from throwing warnings about reading uninitialised
> memory when formatting inodes into the incore log buffer. There are
> several issues here - we don't always log all the fields in the
> inode log format item, and we never log the inode the
> di_next_unlinked field.
>
> In the case of the inode log format item, this is exacerbated
> by the old xfs_inode_log_format structure padding issue. Hence make
> the padded, 64 bit aligned version of the structure the one we always
> use for formatting the log and get rid of the 64 bit variant. This
> means we'll always log the 64-bit version and so recovery only needs
> to convert from the unpadded 32 bit version from older 32 bit
> kernels.
>
> Signed-Off-By: Dave Chinner <dchinner@xxxxxxxxxx>
> Tested-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/libxfs/xfs_log_format.h | 27 +++++----------
> fs/xfs/xfs_inode_item.c | 79 ++++++++++++++++++++++--------------------
> fs/xfs/xfs_ondisk.h | 2 +-
> 3 files changed, 50 insertions(+), 58 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
> index 8372e9bcd7b6..71de185735e0 100644
> --- a/fs/xfs/libxfs/xfs_log_format.h
> +++ b/fs/xfs/libxfs/xfs_log_format.h
> @@ -270,6 +270,7 @@ typedef struct xfs_inode_log_format {
> uint32_t ilf_fields; /* flags for fields logged */
> uint16_t ilf_asize; /* size of attr d/ext/root */
> uint16_t ilf_dsize; /* size of data/ext/root */
> + uint32_t ilf_pad; /* pad for 64 bit boundary */
> uint64_t ilf_ino; /* inode number */
> union {
> uint32_t ilfu_rdev; /* rdev value for dev inode*/
> @@ -280,29 +281,17 @@ typedef struct xfs_inode_log_format {
> int32_t ilf_boffset; /* off of inode in buffer */
> } xfs_inode_log_format_t;
>
> -typedef struct xfs_inode_log_format_32 {
> - uint16_t ilf_type; /* inode log item type */
> - uint16_t ilf_size; /* size of this item */
> - uint32_t ilf_fields; /* flags for fields logged */
> - uint16_t ilf_asize; /* size of attr d/ext/root */
> - uint16_t ilf_dsize; /* size of data/ext/root */
> - uint64_t ilf_ino; /* inode number */
> - union {
> - uint32_t ilfu_rdev; /* rdev value for dev inode*/
> - uuid_t ilfu_uuid; /* mount point value */
> - } ilf_u;
> - int64_t ilf_blkno; /* blkno of inode buffer */
> - int32_t ilf_len; /* len of inode buffer */
> - int32_t ilf_boffset; /* off of inode in buffer */
> -} __attribute__((packed)) xfs_inode_log_format_32_t;
> -
> -typedef struct xfs_inode_log_format_64 {
> +/*
> + * Old 32 bit systems will log in this format without the 64 bit
> + * alignment padding. Recovery will detect this and convert it to the
> + * correct format.
> + */
> +struct xfs_inode_log_format_32 {
> uint16_t ilf_type; /* inode log item type */
> uint16_t ilf_size; /* size of this item */
> uint32_t ilf_fields; /* flags for fields logged */
> uint16_t ilf_asize; /* size of attr d/ext/root */
> uint16_t ilf_dsize; /* size of data/ext/root */
> - uint32_t ilf_pad; /* pad for 64 bit boundary */
> uint64_t ilf_ino; /* inode number */
> union {
> uint32_t ilfu_rdev; /* rdev value for dev inode*/
> @@ -311,7 +300,7 @@ typedef struct xfs_inode_log_format_64 {
> int64_t ilf_blkno; /* blkno of inode buffer */
> int32_t ilf_len; /* len of inode buffer */
> int32_t ilf_boffset; /* off of inode in buffer */
> -} xfs_inode_log_format_64_t;
> +} __attribute__((packed));
>
>
> /*
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index a705f34b58fa..9bbc2d7cc8cb 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -364,6 +364,9 @@ xfs_inode_to_log_dinode(
> to->di_dmstate = from->di_dmstate;
> to->di_flags = from->di_flags;
>
> + /* log a dummy value to ensure log structure is fully initialised */
> + to->di_next_unlinked = NULLAGINO;
> +
> if (from->di_version == 3) {
> to->di_changecount = inode->i_version;
> to->di_crtime.t_sec = from->di_crtime.t_sec;
> @@ -404,6 +407,11 @@ xfs_inode_item_format_core(
> * the second with the on-disk inode structure, and a possible third and/or
> * fourth with the inode data/extents/b-tree root and inode attributes
> * data/extents/b-tree root.
> + *
> + * Note: Always use the 64 bit inode log format structure so we don't
> + * leave an uninitialised hole in the format item on 64 bit systems. Log
> + * recovery on 32 bit systems handles this just fine, so there's no reason
> + * for not using an initialising the properly padded structure all the time.
> */
> STATIC void
> xfs_inode_item_format(
> @@ -412,8 +420,8 @@ xfs_inode_item_format(
> {
> struct xfs_inode_log_item *iip = INODE_ITEM(lip);
> struct xfs_inode *ip = iip->ili_inode;
> - struct xfs_inode_log_format *ilf;
> struct xfs_log_iovec *vecp = NULL;
> + struct xfs_inode_log_format *ilf;
>
> ASSERT(ip->i_d.di_version > 1);
>
> @@ -425,7 +433,17 @@ xfs_inode_item_format(
> ilf->ilf_boffset = ip->i_imap.im_boffset;
> ilf->ilf_fields = XFS_ILOG_CORE;
> ilf->ilf_size = 2; /* format + core */
> - xlog_finish_iovec(lv, vecp, sizeof(struct xfs_inode_log_format));
> +
> + /*
> + * make sure we don't leak uninitialised data into the log in the case
> + * when we don't log every field in the inode.
> + */
> + ilf->ilf_dsize = 0;
> + ilf->ilf_asize = 0;
> + ilf->ilf_pad = 0;
> + uuid_copy(&ilf->ilf_u.ilfu_uuid, &uuid_null);
> +
> + xlog_finish_iovec(lv, vecp, sizeof(*ilf));
>
> xfs_inode_item_format_core(ip, lv, &vecp);
> xfs_inode_item_format_data_fork(iip, ilf, lv, &vecp);
> @@ -855,44 +873,29 @@ xfs_istale_done(
> }
>
> /*
> - * convert an xfs_inode_log_format struct from either 32 or 64 bit versions
> - * (which can have different field alignments) to the native version
> + * convert an xfs_inode_log_format struct from the old 32 bit version
> + * (which can have different field alignments) to the native 64 bit version
> */
> int
> xfs_inode_item_format_convert(
> - xfs_log_iovec_t *buf,
> - xfs_inode_log_format_t *in_f)
> + struct xfs_log_iovec *buf,
> + struct xfs_inode_log_format *in_f)
> {
> - if (buf->i_len == sizeof(xfs_inode_log_format_32_t)) {
> - xfs_inode_log_format_32_t *in_f32 = buf->i_addr;
> -
> - in_f->ilf_type = in_f32->ilf_type;
> - in_f->ilf_size = in_f32->ilf_size;
> - in_f->ilf_fields = in_f32->ilf_fields;
> - in_f->ilf_asize = in_f32->ilf_asize;
> - in_f->ilf_dsize = in_f32->ilf_dsize;
> - in_f->ilf_ino = in_f32->ilf_ino;
> - /* copy biggest field of ilf_u */
> - uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f32->ilf_u.ilfu_uuid);
> - in_f->ilf_blkno = in_f32->ilf_blkno;
> - in_f->ilf_len = in_f32->ilf_len;
> - in_f->ilf_boffset = in_f32->ilf_boffset;
> - return 0;
> - } else if (buf->i_len == sizeof(xfs_inode_log_format_64_t)){
> - xfs_inode_log_format_64_t *in_f64 = buf->i_addr;
> -
> - in_f->ilf_type = in_f64->ilf_type;
> - in_f->ilf_size = in_f64->ilf_size;
> - in_f->ilf_fields = in_f64->ilf_fields;
> - in_f->ilf_asize = in_f64->ilf_asize;
> - in_f->ilf_dsize = in_f64->ilf_dsize;
> - in_f->ilf_ino = in_f64->ilf_ino;
> - /* copy biggest field of ilf_u */
> - uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f64->ilf_u.ilfu_uuid);
> - in_f->ilf_blkno = in_f64->ilf_blkno;
> - in_f->ilf_len = in_f64->ilf_len;
> - in_f->ilf_boffset = in_f64->ilf_boffset;
> - return 0;
> - }
> - return -EFSCORRUPTED;
> + struct xfs_inode_log_format_32 *in_f32 = buf->i_addr;
> +
> + if (buf->i_len != sizeof(*in_f32))
> + return -EFSCORRUPTED;
> +
> + in_f->ilf_type = in_f32->ilf_type;
> + in_f->ilf_size = in_f32->ilf_size;
> + in_f->ilf_fields = in_f32->ilf_fields;
> + in_f->ilf_asize = in_f32->ilf_asize;
> + in_f->ilf_dsize = in_f32->ilf_dsize;
> + in_f->ilf_ino = in_f32->ilf_ino;
> + /* copy biggest field of ilf_u */
> + uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f32->ilf_u.ilfu_uuid);
> + in_f->ilf_blkno = in_f32->ilf_blkno;
> + in_f->ilf_len = in_f32->ilf_len;
> + in_f->ilf_boffset = in_f32->ilf_boffset;
> + return 0;
> }
> diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
> index 0c381d71b242..0492436a053f 100644
> --- a/fs/xfs/xfs_ondisk.h
> +++ b/fs/xfs/xfs_ondisk.h
> @@ -134,7 +134,7 @@ xfs_check_ondisk_structs(void)
> XFS_CHECK_STRUCT_SIZE(struct xfs_icreate_log, 28);
> XFS_CHECK_STRUCT_SIZE(struct xfs_ictimestamp, 8);
> XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_32, 52);
> - XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_64, 56);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format, 56);
> XFS_CHECK_STRUCT_SIZE(struct xfs_qoff_logformat, 20);
> XFS_CHECK_STRUCT_SIZE(struct xfs_trans_header, 16);
> }
> --
> 2.14.2
>
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