lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20100624131455.GA10441@laptop>
Date:	Thu, 24 Jun 2010 23:14:55 +1000
From:	Nick Piggin <npiggin@...e.de>
To:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	Al Viro <viro@...IV.linux.org.uk>,
	Ulrich Drepper <drepper@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [rfc] new stat*fs-like syscall?

This has come up a few times in the past, and I'd like to try to get
an agreement on it. statvfs(2) importantly contains f_flag (mount
flags), and is encouraged to use rather than statfs(2). The kernel
provides a statfs syscall only.

This means glibc has to provide f_flag support by parsing /proc/mounts
and stat(2)ing mount points. This is really slow, and /proc/mounts is
hard for the kernel to provide. It's actually the last scalability
bottleneck in the core vfs for dbench (samba) after my patches.

Not only that, but it's racy.

Other than types, other differences are:
- statvfs(2) has is f_frsize, which seems fairly useless.
- statvfs(2) has f_favail.
- statfs(2) f_bsize is optimal transfer block, statvfs(2) f_bsize is fs
  block size. The latter could be useful for disk space algorithms.
  Both can be ill defned.
- statvfs(2) lacks f_type.

Is there anything more we should add here? Samba wants a capabilities
field, with things like sparse files, quotas, compression, encryption,
case preserving/sensitive.

Any thoughts?

Thanks,
Nick

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

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ