On Thu, Oct 04, 2018 at 10:57:49PM +0200, Stefan Ring wrote:
> I have empirically found and tried to fix some places where stale data was not properly zeroed out.
>
> In the order of the code changes:
>
> The "freeindex" blocks in inode directories, from last entry to end of block.
>
> XFS_DIR2_LEAF1_MAGIC, from last entry to end of block.
>
> In btree format inodes before as well as after the btree pointers.
>
> In dev inodes, everything after the header.
Mostly looks ok, but with some style issues:
> ---
> db/metadump.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 69 insertions(+), 5 deletions(-)
>
> diff --git a/db/metadump.c b/db/metadump.c
> index cc2ae9af..e7159cd1 100644
> --- a/db/metadump.c
> +++ b/db/metadump.c
> @@ -1421,12 +1421,42 @@ process_sf_attr(
> memset(asfep, 0, XFS_DFORK_ASIZE(dip, mp) - ino_attr_size);
> }
>
> +static void
> +process_dir_free_block(
> + char *block)
> +{
> + struct xfs_dir2_free *free;
> + struct xfs_dir3_icfree_hdr freehdr;
> +
> + if (!zero_stale_data)
> + return;
> +
> + free = (struct xfs_dir2_free *)block;
> + M_DIROPS(mp)->free_hdr_from_disk(&freehdr, free);
> +
> + /* Zero out space from end of bests[] to end of block */
> + if (freehdr.magic == XFS_DIR2_FREE_MAGIC) {
How about XFS_DIR3_FREE_MAGIC ?
> + __be16 *bests;
> + char *high;
> + int used;
> +
> + bests = M_DIROPS(mp)->free_bests_p(free);
> + high = (char *)&bests[freehdr.nvalid];
> + used = high - (char*)free;
> + memset(high, 0, mp->m_sb.sb_blocksize - used);
> + iocur_top->need_crc = 1;
> + }
> + else if (show_warnings)
Though perhaps this should be structured as:
switch (freehdr.magic) {
case XFS_DIR3_FREE_MAGIC:
case XFS_DIR2_FREE_MAGIC:
/* clear stuff */
break;
default:
if (show_warnings)
print_warning(...);
break;
}
> + print_warning("invalid magic in dir inode %llu free block",
> + (unsigned long long)cur_ino);
> +}
> +
> static void
> process_dir_leaf_block(
> char *block)
> {
> struct xfs_dir2_leaf *leaf;
> - struct xfs_dir3_icleaf_hdr leafhdr;
> + struct xfs_dir3_icleaf_hdr leafhdr;
>
> if (!zero_stale_data)
> return;
> @@ -1449,6 +1479,18 @@ process_dir_leaf_block(
> lbp = xfs_dir2_leaf_bests_p(ltp);
> memset(free, 0, (char *)lbp - free);
> iocur_top->need_crc = 1;
> + } else
> + if (leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
> + leafhdr.magic == XFS_DIR3_LEAFN_MAGIC) {
Convert this whole thing to a switch?
> + struct xfs_dir2_leaf_entry *ents;
> + char *free;
> + int used;
> +
> + ents = M_DIROPS(mp)->leaf_ents_p(leaf);
> + free = (char *)&ents[leafhdr.count];
> + used = free - (char*)leaf;
> + memset(free, 0, mp->m_sb.sb_blocksize - used);
> + iocur_top->need_crc = 1;
> }
> }
>
> @@ -1499,7 +1541,7 @@ process_dir_data_block(
> if (show_warnings)
> print_warning(
> "invalid magic in dir inode %llu block %ld",
> - (long long)cur_ino, (long)offset);
> + (unsigned long long)cur_ino, (long)offset);
Unrelated (but still good) change.
> return;
> }
>
> @@ -1813,8 +1855,7 @@ process_single_fsb_objects(
> switch (btype) {
> case TYP_DIR2:
> if (o >= mp->m_dir_geo->freeblk) {
> - /* TODO, zap any stale data */
> - break;
> + process_dir_free_block(dp);
> } else if (o >= mp->m_dir_geo->leafblk) {
> process_dir_leaf_block(dp);
> } else {
> @@ -2115,6 +2156,20 @@ process_btinode(
> }
>
> pp = XFS_BMDR_PTR_ADDR(dib, 1, maxrecs);
> +
> + if (zero_stale_data) {
> + /* Space before btree pointers */
> + char *top;
> + int used;
> + top = (char*)XFS_BMDR_PTR_ADDR(dib, 1, nrecs);
Blank line between "int used;" and "top =...", please.
> + memset(top, 0, (char*)pp - top);
> +
> + /* Space after btree pointers */
> + top = (char*)&pp[nrecs];
> + used = top - (char*)dip;
> + memset(top, 0, mp->m_sb.sb_inodesize - used);
> + }
> +
> for (i = 0; i < nrecs; i++) {
> xfs_agnumber_t ag;
> xfs_agblock_t bno;
> @@ -2250,7 +2305,16 @@ process_inode(
> case S_IFREG:
> success = process_inode_data(dip, TYP_DATA);
> break;
> - default: ;
> + default:
> + if (XFS_DFORK_NEXTENTS(dip, XFS_ATTR_FORK) ||
> + XFS_DFORK_NEXTENTS(dip, XFS_DATA_FORK)) {
Please line up the XFS_DFORK_NEXTENTS(...) calls.
> + if (show_warnings)
> + print_warning("inode %llu has unexpected extents",
> + (unsigned long long)cur_ino);
> + success = 0;
> + }
> + else
} else
memset(...)
> + memset(XFS_DFORK_DPTR(dip), 0, mp->m_sb.sb_inodesize - (XFS_DFORK_DPTR(dip) - (char*)dip));
Please put this in a separate helper that isn't triple-indented and
overflows 80 columns.
--D
> }
> nametable_clear();
>
> --
> 2.14.4
>
