I reviewed this by generating 100 random files via the following command:

seq -w 1 100 | xargs -n1 -I% sh -c 'dd if=/dev/urandom of=file.% 
bs=$(shuf -i1-10 -n1) count=1024'

Then I created a backup from those files, recreated the files with the 
above command and created a second backup.

Additionally I created a 3rd backup where I:

  * changed uid & gid of 10 files
  * changed permissions of 10 files
  * deleted 10 files
  * created 10 new files
  * moved some of the files into a new subdirectory
  * touched 10 files

All changes between 1 ->2 and 2 -> 3 and 1 -> 3 were picked up by the 
diff tool as far as I could tell.

Some files where the content has changed but everything else stayed the 
same (except for mtime), were not marked as changed without the flag 
--compare-content. Maybe we should not mark any files as changed without 
the --compare-content flag or we should mark all files as changed where 
any attribute changed?

With --compare-content the changes were picked up, which is what this 
flag is for, so I think it's OK.


Code LGTM!


Reviewed-by: Stefan Hanreich <s.hanreich@proxmox.com>
Tested-by: Stefan Hanreich <s.hanreich@proxmox.com>

On 11/29/22 15:17, Lukas Wagner wrote:
> This patch series contains a few improvements for the `diff archive` tool,
> mainly based on Wolfgang's suggestions.
>
> First, the output of is now much more detailed and shows
> some relevant file attributes, including what has changed between
> snapshots. Changed attributes are highlighted by a "*".
>
> For instance:
>
> $ proxmox-backup-debug diff archive ...
> A  f   644  10045  10000     0 B  2022-11-28 13:44:51  add.txt
> M  f   644  10045  10000     6 B *2022-11-28 13:45:05  content.txt
> D  f   644  10045  10000     0 B  2022-11-28 13:17:09  deleted.txt
> M  f   644  10045    *29     0 B  2022-11-28 13:16:20  gid.txt
> M  f  *777  10045  10000     0 B  2022-11-28 13:42:47  mode.txt
> M  f   644  10045  10000     0 B *2022-11-28 13:44:33  mtime.txt
> M  f   644  10045  10000    *7 B *2022-11-28 13:44:59 *size.txt
> M  f   644 *64045  10000     0 B  2022-11-28 13:16:18  uid.txt
> M *f   644  10045  10000    10 B  2022-11-28 13:44:59  type.txt
>
> The second commit introduces the possiblity to pass
> the --compare-content flag to the tool. If the flag is passed,
> the tool will compare the file content instead of relying on mtime
> alone to detect modifications.
>
> Lukas Wagner (2):
>    debug cli: show more file attributes for `diff archive` command
>    debug cli: add 'compare-content' flag to `diff archive` command
>
>   src/bin/proxmox_backup_debug/diff.rs | 356 ++++++++++++++++++++++-----
>   1 file changed, 299 insertions(+), 57 deletions(-)
>