On Mar 8, 2021, at 2:40 PM, Theodore Ts'o <tytso@xxxxxxx> wrote: > > On Mon, Mar 08, 2021 at 12:01:46PM -0800, George Goffe wrote: >> Howdy, >> >> I'm helping to shoot a bug on a Fedora Core 35 system and have been >> requested to provide a meta-data dump of the problem filesystem. The >> filenames are restricted so I need to scrub this file before sending >> it. >> >> Does ext4 have a facility whereby I can scrub the filenames from the dump? > > Yes, please see the following excerpt from the e2image man page: > > This will only send the metadata information, without any data > blocks. However, the filenames in the directory blocks can still > reveal information about the contents of the filesystem that the > bug reporter may wish to keep confidential. To address this > concern, the -s option can be specified. This will cause e2image > to scramble directory entries and zero out any unused portions of > the directory blocks before writing the image file. However, the > -s option will prevent analysis of problems related to hash-tree > indexed directories. I had actually looked for this option in the e2image man page in order to reply to this email, but I couldn't find it and wondered if I had mis-remembered the existence of this functionality. I've pushed a patch that reorganizes the e2image man page to list all of the options explicitly in a separate OPTIONS section, rather than putting them inline in the text, which makes it hard to find them. Cheers, Andreas > The -s option can be used with the -r and -Q options to e2image, for > creating raw and qcow2 image dumps, respectively. Because the > filenames have been scrambled, this will invalidate the hash-tree > indexes for the directory, so e2fsck will complain about this. But > for some kinds of corruption, the -s option can provide data when the > customer would otherwise not be willing to provide a metadata-only > dump of the file system. > > Hope this helps, > > - Ted Cheers, Andreas
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