Add ordered directory traversal

[mpolitzer]

No description provided.

[josch]

I'm not involved in the development of genext2fs but you asked for a review so here you have it.
My only other suggestion would be to add a unit test that uses disorderfs to show that your patch works.

[josch]

alphasort is locale aware. You need to set LC_COLLATE to a fixed value like C to produce the same output independent of the user's locale

[mpolitzer]

The man page states that this is already the default behavior. Would you rather make it explicit?

...
On startup of the main program, the portable "C" locale is selected as default.
...

[josch]

you are right!

[josch]

Here is an idea how a test for this feature could look like:

$ mkdir rootdir sorted reversed
$ touch rootdir/a rootdir/b rootdir/c
$ disorderfs --sort-dirents=yes --reverse-dirents=no rootdir sorted
disorderfs: sorting directory entries
$ disorderfs --sort-dirents=yes --reverse-dirents=yes rootdir reversed
disorderfs: reversing directory entries
disorderfs: sorting directory entries
$ SOURCE_DATE_EPOCH=0 genext2fs --size-in-blocks 1000 --root sorted out1.img
copying from directory sorted
$ SOURCE_DATE_EPOCH=0 genext2fs --size-in-blocks 1000 --root reversed out2.img
copying from directory reversed
$ cmp out1.img out2.img
out1.img out2.img differ: byte 7221, line 3
$ SOURCE_DATE_EPOCH=0 ~/git/genext2fs/genext2fs --size-in-blocks 1000 --root sorted out1.img
copying from directory sorted
$ SOURCE_DATE_EPOCH=0 ~/git/genext2fs/genext2fs --size-in-blocks 1000 --root reversed out2.img
copying from directory reversed
$ cmp out1.img out2.img
$ echo $?
0
$ fusermount -u sorted
$ fusermount -u reversed

As expected, the images differ without your patch and they are identical with your patch.

[bestouff]

@josch :

I'm not involved in the development of genext2fs

Yes but you're more active than me; I'd really like to handle you maintainership of genext2fs. Or at the very least nominate you co-maintainer as github settings permit.

@mpolitzer sorry for the OT rant

[mpolitzer]

@josch :

I'm not involved in the development of genext2fs

Yes but you're more active than me; I'd really like to handle you maintainership of genext2fs. Or at the very least nominate you co-maintainer as github settings permit.

@mpolitzer sorry for the OT rant

No problem

[mpolitzer]

Hello @josch and @bestouff,

This PR is ready for another review pass.
I updated it by adding a disorderfs test to the test.sh file in the lines of @josch suggestion.

[josch]

These changes look good to me now.

@bestouff after merging this, could you tag a new release?

[mpolitzer]

bump