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
| ||
|
Date: Wed, 15 Jan 2014 18:31:50 -0500 From: "J. Bruce Fields" <bfields@...ldses.org> To: Miklos Szeredi <miklos@...redi.hu> Cc: Al Viro <viro@...iv.linux.org.uk>, Linus Torvalds <torvalds@...ux-foundation.org>, Linux-Fsdevel <linux-fsdevel@...r.kernel.org>, Kernel Mailing List <linux-kernel@...r.kernel.org>, Christoph Hellwig <hch@...radead.org>, Andrew Morton <akpm@...ux-foundation.org>, David Howells <dhowells@...hat.com>, Zach Brown <zab@...hat.com>, Jan Kara <jack@...e.cz>, Andy Lutomirski <luto@...capital.net>, "mszeredi@...e.cz" <mszeredi@...e.cz> Subject: Re: [PATCH 05/11] vfs: add RENAME_NOREPLACE flag On Wed, Jan 15, 2014 at 07:35:04PM +0100, Miklos Szeredi wrote: > On Wed, Jan 15, 2014 at 7:19 PM, J. Bruce Fields <bfields@...ldses.org> wrote: > > On Wed, Jan 08, 2014 at 11:10:09PM +0100, Miklos Szeredi wrote: > >> From: Miklos Szeredi <mszeredi@...e.cz> > >> > >> If this flag is specified and the target of the rename exists then the > >> rename syscall fails with EEXIST. > > > > Why is this useful? > > > > (I'm sure it is, it'd just be useful to have the reasons recorded > > someplace.) > > > >> The VFS does the existence checking, so it is trivial to enable for most > >> local filesystems. This patch only enables it in ext4. > >> > >> For network filesystems the VFS check is not enough as there may be a race > >> between a remote create and the rename, so these filesystems need to handle > >> this flag in their ->rename() implementations to ensure atomicity. > > > > Till that's done this should probably result in -EOPNOTSUPP on those > > filesystems? > > > > I think this would need new protocol in the NFS case. > > Yes, it needs to be enabled on a case-by-case basis. Oh, right, I missed all those if (flags) return -EOPNOTSUPP; added with "vfs: add renameat2 syscall". Apologies. > Only enabled for > ext4 now, but trivial to do for most fs. Got it, thanks! --b. -- 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