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Groups > linux.kernel > #1359581
| From | Gregory Farnum <greg@gregs42.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks |
| Date | 2016-03-17 06:20 +0100 |
| Message-ID | <rdyvM-2PK-3@gated-at.bofh.it> (permalink) |
| References | (7 earlier) <rd66u-9k-9@gated-at.bofh.it> <rd8UG-1Z1-11@gated-at.bofh.it> <rdruj-6nD-23@gated-at.bofh.it> <rdtPs-89y-15@gated-at.bofh.it> <rdu8P-8hX-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Mar 16, 2016 at 5:33 PM, Eric Sandeen <esandeen@redhat.com> wrote: > I may have lost the thread at this point, with poor Darrick's original > patch submission devolving into a long thread about a NO_HIDE_STALE patch > used at Google, but I don't *think* Ceph ever asked for NO_HIDE_STALE. > > At least I can't find any indication of that. > > Am I missing something? cc'ing Greg on this one in case I am. Brief background: Ceph currently has two big local storage subsystems: FileStore and BlueStore. FileStore is the one that's been around for forever and is currently stable/production-ready/bla bla bla. This one represents RADOS objects as actual files and while it's *mostly* just converting object operations into posix FS ones, it does rely on a few pieces of the fs namespace and posix ops to do its work. BlueStore is our new, pure userspace solution (Sage started this about 8 months ago, I think?). It started out using xfs basically as a block allocator, but at this point it's just doing raw block access 100% in userspace. So we've not asked for NO_HIDE_STALE on the mailing lists, but I think it was one of the problems Sage had using xfs in his BlueStore implementation and was a big part of why it moved to pure userspace. FileStore might use NO_HIDE_STALE in some places but it would be pretty limited. When it came up at Linux FAST we were discussing how it and similar things had been problems for us in the past and it would've been nice if they were upstream. What *is* a big deal for FileStore (and would be easy to take advantage of) is the thematically similar O_NOMTIME flag, which is also about reducing metadata updates and got blocked on similar stupid-user grounds (although not security ones): http://thread.gmane.org/gmane.linux.kernel.api/10727. As noted though, we've basically given up and are moving to a pure-userspace solution as quickly as we can. So no, Ceph isn't likely to be a big user of these interfaces as it's too late for us. Adding them would be an investment for future distributed storage systems more than current ones. Maybe that's not worth it, or maybe there are better places to keep them in the kernel. (I think I saw a reference to some hypothetical shared block allocator? That would be *awesome*.) ========= Separately. In the particular case of the extents and data leaks, a coworker of mine suggested you could tag any files which *ever* had unwritten extents with something that prevents them being read by a user who doesn't have raw block access (and, even better, let us apply that flag on file create)...that's a weird new security rule for people to know and requires space for tagging (no idea how bad that is), but would work in any use cases we have and would not leak anything the user doesn't already have access to. -Greg
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Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Gregory Farnum <greg@gregs42.com> - 2016-03-09 23:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-10 00:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Ric Wheeler <ricwheeler@gmail.com> - 2016-03-10 16:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-10 19:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-10 22:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Ric Wheeler <rwheeler@redhat.com> - 2016-03-11 05:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-03-11 15:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-11 16:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-11 18:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Andy Lutomirski <luto@amacapital.net> - 2016-03-11 18:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-11 19:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-11 23:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-12 01:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-12 01:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-12 08:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Thomas Schoebel-Theuer <tst@schoebel-theuer.de> - 2016-03-12 11:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-14 00:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Ric Wheeler <rwheeler@redhat.com> - 2016-03-14 11:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-14 15:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-15 21:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-15 21:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-15 22:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-15 23:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-16 00:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks "Darrick J. Wong" <darrick.wong@oracle.com> - 2016-03-16 03:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Andreas Dilger <adilger@dilger.ca> - 2016-03-16 22:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-17 01:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Eric Sandeen <esandeen@redhat.com> - 2016-03-17 01:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-17 02:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Gregory Farnum <greg@gregs42.com> - 2016-03-17 06:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-17 13:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-17 18:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-17 19:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Ric Wheeler <rwheeler@redhat.com> - 2016-03-17 19:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Chris Mason <clm@fb.com> - 2016-03-17 19:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Andreas Dilger <adilger@dilger.ca> - 2016-03-17 21:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Chris Mason <clm@fb.com> - 2016-03-17 22:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Theodore Ts'o <tytso@mit.edu> - 2016-03-18 04:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Jeff Moyer <jmoyer@redhat.com> - 2016-03-18 16:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks "Martin K. Petersen" <martin.petersen@oracle.com> - 2016-03-18 21:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Gregory Farnum <greg@gregs42.com> - 2016-03-18 08:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-18 08:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-17 02:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks "Darrick J. Wong" <darrick.wong@oracle.com> - 2016-03-17 03:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks NeilBrown <neilb@suse.com> - 2016-03-19 00:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-16 00:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-16 00:20 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-16 01:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Dave Chinner <david@fromorbit.com> - 2016-03-16 01:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-16 01:10 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Eric Sandeen <esandeen@redhat.com> - 2016-03-16 01:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Chris Mason <clm@fb.com> - 2016-03-16 02:00 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Chris Mason <clm@fb.com> - 2016-03-16 23:30 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Ric Wheeler <rwheeler@redhat.com> - 2016-03-17 14:50 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Eric Sandeen <esandeen@redhat.com> - 2016-03-15 23:40 +0100
Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Linus Torvalds <torvalds@linux-foundation.org> - 2016-03-12 01:40 +0100
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