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From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Stefan Ring <stefanrin@gmail.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 1/1] xfs_metadump: Zap more stale data
Date: Fri, 5 Oct 2018 13:40:57 -0700	[thread overview]
Message-ID: <20181005204057.GB19324@magnolia> (raw)
In-Reply-To: <CAAxjCEw0prn7P3dn-OuuxbmMTgzs2HydpZsgkwH8RVBkedQXOA@mail.gmail.com>

On Fri, Oct 05, 2018 at 10:35:34PM +0200, Stefan Ring wrote:
> On Thu, Oct 4, 2018 at 10:57 PM Stefan Ring <stefanrin@gmail.com> wrote:
> > 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) {
> > +               __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)
> > +               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) {
> > +               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);
> 
> I forgot to mention this: sb_blocksize is used conspicuously rarely in
> this file. Is this the right metric to lean on?

No, because directory blocks span multiple fs blocks (good self catch!).

You could look it up in the directory geometry structure in the
xfs_mount *.

--D

> > +               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);
> >                 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);
> > +               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)) {
> > +                               if (show_warnings)
> > +                                       print_warning("inode %llu has unexpected extents",
> > +                                                       (unsigned long long)cur_ino);
> > +                               success = 0;
> > +                       }
> > +                       else
> > +                               memset(XFS_DFORK_DPTR(dip), 0, mp->m_sb.sb_inodesize - (XFS_DFORK_DPTR(dip) - (char*)dip));
> >         }
> >         nametable_clear();
> >
> > --
> > 2.14.4
> >

  reply	other threads:[~2018-10-06  3:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-04 20:57 [PATCH 0/1] Try to squash metadump data leaks Stefan Ring
2018-10-04 20:57 ` [PATCH 1/1] xfs_metadump: Zap more stale data Stefan Ring
2018-10-04 22:23   ` Darrick J. Wong
2018-10-05 20:46     ` Stefan Ring
2018-10-05 20:57       ` Darrick J. Wong
2018-10-05 20:35   ` Stefan Ring
2018-10-05 20:40     ` Darrick J. Wong [this message]
2018-10-07  9:43       ` Stefan Ring
2018-10-07 11:57         ` Stefan Ring
2018-10-07 16:21           ` Darrick J. Wong
2018-10-10  9:37           ` Stefan Ring

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