Re: [PATCH 12/35] Unionfs: Documentation

From: Jan Engelhardt
Date: Tue Dec 05 2006 - 15:59:38 EST



>+++ b/Documentation/filesystems/unionfs/00-INDEX
>@@ -0,0 +1,8 @@
>+00-INDEX
>+ - this file.
>+concepts.txt
>+ - A brief introduction of concepts
>+rename.txt
>+ - Information regarding rename operations
>+usage.txt
>+ - Usage & known limitations

Try "and", & is so... 'lazy'.


>+Since 'foo' is stored on a read-only branch, it cannot be removed. A whiteout
>+is used to remove the name 'foo' from the unified namespace. Again, since
>+branch 1 is read-only, the whiteout cannot be created there. So, we try on a
>+higher priority (lower numerically) branch. And there we create the whiteout.

higher priority (numerically lower) branch and create the whiteout there.
(Starting a sentence with 'and' is like telling fairytales^W stories.)

>+solution is to take the instance from the highest priority (lowest numerical
>+value) and "hide" the others.

(numerically lowest value)

>+When a change is made to the contents of a file's data or meta-data, they
>+have to be stored somewhere. The best way is to create a copy of the
>+original file on a branch that is writable, and then redirect the write
>+though to this copy. The copy must be made on a higher priority branch so
>+that lookup & readdir return this newer "version" of the file rather than
>+the original (see duplicate elimination).

s/&/and/g;

>+Modifying a Unionfs branch directly, while the union is mounted is currently
>+unsupported.

Either:
Modifying a Unionfs branch directly while the union
is mounted is currently unsupported.
Or:
Modifying a Unionfs branch directly, while the union
is mounted, is currently unsupported.

> Any such change can cause Unionfs to oops, however it could even
>+RESULT IN DATA LOSS.

Or stay silent (-> silent data corruption / loss)

>+Unionfs shouldn't use lookup_one_len on the underlying fs as it confuses

For written text, non-shortened forms (should not) are preferred. At least
that's (<- that's texified speech not documentation) what we were told back in
scool :p

>+NFS. Currently, unionfs_lookup passes lookup intents to the lower

should not use lookup_one_len() [...] Currently, unionfs_lookup()

most doc add () to clarify it is a function.

>+filesystem, this eliminates part of the problem. The remaining calls to
>+lookup_one_len may need to be changed to pass an intent.

~

-`J'
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/