Not logged in
Log in now
Create an account
Subscribe to LWN
LWN.net Weekly Edition for May 23, 2013
An "enum" for Python 3
An unexpected perf feature
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
Which is exactly what our applications are doing. POSIX says, commit. We don't and then we blame others for it.
This is the same thing HTML5 is doing
Posted Mar 15, 2009 22:33 UTC (Sun) by khim (subscriber, #9252)
Sorry, but it's not the problem with POSIX or FS - it's problem with
number of applications. Once a lot of applications are starting to depend
on some weird feature (content sniffing in case of HTML, atomicity of
open/write/close/rename on case of filesystem) it makes no sense to try to
fix them all. Much better to document it and make it official. This is what
Microsoft did with a lot of "internal" functions in MS-DOS 5 (and it was
praised for it, not ostracized), this is what HTML is doing in HTML5 and
this is what Linux filesystems should do.
Was it good idea to depend on said atomicity? May be, may be not. But
the time to fix these problems come and gone - today it's much better to
extend the spec.
Posted Mar 15, 2009 23:37 UTC (Sun) by bojan (subscriber, #14302)
Time to fix these problems using the existing API is now, because right now we have the attention of everyone on how to use the API properly. To the credit of some in this discussion, bugs are already being fixed in Gnome (as I already mentioned in another comment). I also have bugs to fix in my own code - there is no denying that :-(
In general, I agree with you on extending the spec. But, before the spec gets extended officially, we need to make sure that _every_ POSIX compliant file system implements it that way. Otherwise, apps depending on this new spec will not be reliable until that's the case. So, can we actually make sure that's the case? I very much doubt it. There is a lot of different systems out there that are implementing POSIX, some of them very old. Auditing all of them and then fixing them may be harder than fixing the applications.
Why do we need such blessing?
Posted Mar 16, 2009 0:05 UTC (Mon) by khim (subscriber, #9252)
Linux extends POSIX all the time. New syscalls, new features (things
like "According to the standard specification (e.g., POSIX.1-2001),
sync() schedules the writes, but may return before the actual writing is
done. However, since version 1.3.20 Linux does actually wait."), etc.
If application wants to use such "extended feature" - it can do this, if
not - it can use POSIX-approved features only.
As for old POSIX systems... it's up to application writers again. And
you can be pretty sure A LOT OF them don't give a damn about POSIX
compliance. They are starting to consider Linux as third platfrom for their
products (first two are obviously Windows and MacOS in that order), but if
you'll try to talk to them about POSIX it'll just lead to the removal of
Linux from list of supported platforms. Support of many distributions is
already hard enough, support of some exotic filesystems "we'll think about
it but don't hold your breath...", support for old exotic POSIX systems...
Now - the interesting question is: do we welcome such selfish developers
or not? This is hard question because the answer "no, they should play by
our rules" will just lead to exodus of users - because they need these
applications and WINE is not a good long-term solution...
Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds