From: "NeilBrown" <neilb@suse.de>
To: "Zygo Blaxell" <ce3g8jdj@umail.furryterror.org>
Cc: "Wang Yugui" <wangyugui@e16-tech.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Josef Bacik" <josef@toxicpanda.com>,
"J. Bruce Fields" <bfields@fieldses.org>,
"Chuck Lever" <chuck.lever@oracle.com>,
"Chris Mason" <clm@fb.com>, "David Sterba" <dsterba@suse.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] VFS/BTRFS/NFSD: provide more unique inode number for btrfs export
Date: Tue, 24 Aug 2021 09:22:05 +1000 [thread overview]
Message-ID: <162976092544.9892.3996716616493030747@noble.neil.brown.name> (raw)
In-Reply-To: <20210822192917.GF29026@hungrycats.org>
On Mon, 23 Aug 2021, Zygo Blaxell wrote:
...
>
> Subvol IDs are not reusable. They are embedded in shared object ownership
> metadata, and persist for some time after subvols are deleted.
...
>
> The cost of _tracking_ free object IDs is trivial compared to the cost
> of _reusing_ an object ID on btrfs.
One possible approach to these two objections is to decouple inode
numbers from object ids.
The inode number becomes just another piece of metadata stored in the
inode.
struct btrfs_inode_item has four spare u64s, so we could use one of
those.
struct btrfs_dir_item would need to store the inode number too. What
is location.offset used for? Would a diritem ever point to a non-zero
offset? Could the 'offset' be used to store the inode number?
This could even be added to existing filesystems I think. It might not
be easy to re-use inode numbers smaller than the largest at the time the
extension was added, but newly added inode numbers could be reused after
they were deleted.
Just a thought...
NeilBrown
next prev parent reply other threads:[~2021-08-23 23:22 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-27 22:37 [PATCH/RFC 00/11] expose btrfs subvols in mount table correctly NeilBrown
2021-07-27 22:37 ` [PATCH 07/11] exportfs: Allow filehandle lookup to cross internal mount points NeilBrown
2021-07-28 10:13 ` Amir Goldstein
2021-07-29 0:28 ` NeilBrown
2021-07-29 5:27 ` Amir Goldstein
2021-08-06 7:52 ` Miklos Szeredi
2021-08-06 8:08 ` Amir Goldstein
2021-08-06 8:18 ` Miklos Szeredi
2021-07-28 19:17 ` J. Bruce Fields
2021-07-28 22:25 ` NeilBrown
2021-07-27 22:37 ` [PATCH 04/11] VFS: export lookup_mnt() NeilBrown
2021-07-30 0:31 ` Al Viro
2021-07-30 5:33 ` NeilBrown
2021-07-27 22:37 ` [PATCH 01/11] VFS: show correct dev num in mountinfo NeilBrown
2021-07-30 0:25 ` Al Viro
2021-07-30 5:28 ` NeilBrown
2021-07-30 5:54 ` Miklos Szeredi
2021-07-30 6:13 ` NeilBrown
2021-07-30 7:18 ` Miklos Szeredi
2021-07-30 7:33 ` NeilBrown
2021-07-30 7:59 ` Miklos Szeredi
2021-08-02 4:18 ` A Third perspective on BTRFS nfsd subvol dev/inode number issues NeilBrown
2021-08-02 5:25 ` Al Viro
2021-08-02 5:40 ` NeilBrown
2021-08-02 7:54 ` Amir Goldstein
2021-08-02 13:53 ` Josef Bacik
2021-08-03 22:29 ` Qu Wenruo
2021-08-02 14:47 ` Frank Filz
2021-08-02 21:24 ` NeilBrown
2021-08-02 7:15 ` Martin Steigerwald
2021-08-02 21:40 ` NeilBrown
2021-08-02 12:39 ` J. Bruce Fields
2021-08-02 20:32 ` Patrick Goetz
2021-08-02 20:41 ` J. Bruce Fields
2021-08-02 21:10 ` NeilBrown
2021-08-02 21:50 ` J. Bruce Fields
2021-08-02 21:59 ` NeilBrown
2021-08-02 22:14 ` J. Bruce Fields
2021-08-02 22:36 ` NeilBrown
2021-08-03 0:15 ` J. Bruce Fields
2021-07-27 22:37 ` [PATCH 03/11] VFS: pass lookup_flags into follow_down() NeilBrown
2021-07-27 22:37 ` [PATCH 11/11] btrfs: use automount to bind-mount all subvol roots NeilBrown
2021-07-28 8:37 ` kernel test robot
2021-07-28 8:37 ` [RFC PATCH] btrfs: btrfs_mountpoint_expiry_timeout can be static kernel test robot
2021-07-28 13:12 ` [PATCH 11/11] btrfs: use automount to bind-mount all subvol roots Christian Brauner
2021-07-29 0:43 ` NeilBrown
2021-07-29 14:38 ` Christian Brauner
2021-07-31 6:25 ` [btrfs] 5874902268: xfstests.btrfs.202.fail kernel test robot
2021-07-27 22:37 ` [PATCH 06/11] nfsd: include a vfsmount in struct svc_fh NeilBrown
2021-07-27 22:37 ` [PATCH 10/11] btrfs: introduce mapping function from location to inum NeilBrown
2021-07-27 22:37 ` [PATCH 02/11] VFS: allow d_automount to create in-place bind-mount NeilBrown
2021-07-27 22:37 ` [PATCH 09/11] nfsd: Allow filehandle lookup to cross internal mount points NeilBrown
2021-07-28 19:15 ` J. Bruce Fields
2021-07-28 22:29 ` NeilBrown
2021-07-30 0:42 ` Al Viro
2021-07-30 5:43 ` NeilBrown
2021-07-27 22:37 ` [PATCH 08/11] nfsd: change get_parent_attributes() to nfsd_get_mounted_on() NeilBrown
2021-07-27 22:37 ` [PATCH 05/11] VFS: new function: mount_is_internal() NeilBrown
2021-07-28 2:16 ` Al Viro
2021-07-28 3:32 ` NeilBrown
2021-07-30 0:34 ` Al Viro
2021-07-28 2:19 ` [PATCH/RFC 00/11] expose btrfs subvols in mount table correctly Al Viro
2021-07-28 4:58 ` Wang Yugui
2021-07-28 6:04 ` Wang Yugui
2021-07-28 7:01 ` NeilBrown
2021-07-28 12:26 ` Neal Gompa
2021-07-28 19:14 ` J. Bruce Fields
2021-07-29 1:29 ` Zygo Blaxell
2021-07-29 1:43 ` NeilBrown
2021-07-29 23:20 ` Zygo Blaxell
2021-07-28 22:50 ` NeilBrown
2021-07-29 2:37 ` Zygo Blaxell
2021-07-29 3:36 ` NeilBrown
2021-07-29 23:20 ` Zygo Blaxell
2021-07-30 2:36 ` NeilBrown
2021-07-30 5:25 ` Qu Wenruo
2021-07-30 5:31 ` Qu Wenruo
2021-07-30 5:53 ` Amir Goldstein
2021-07-30 6:00 ` NeilBrown
2021-07-30 6:09 ` Qu Wenruo
2021-07-30 5:58 ` NeilBrown
2021-07-30 6:23 ` Qu Wenruo
2021-07-30 6:53 ` NeilBrown
2021-07-30 7:09 ` Qu Wenruo
2021-07-30 18:15 ` Zygo Blaxell
2021-07-30 15:17 ` J. Bruce Fields
2021-07-30 15:48 ` Josef Bacik
2021-07-30 16:25 ` Forza
2021-07-30 17:43 ` Zygo Blaxell
2021-07-30 5:28 ` Amir Goldstein
2021-07-28 13:43 ` g.btrfs
2021-07-29 1:39 ` NeilBrown
2021-07-29 9:28 ` Graham Cobb
2021-07-28 7:06 ` NeilBrown
2021-07-28 9:36 ` Wang Yugui
2021-07-28 19:35 ` J. Bruce Fields
2021-07-28 21:30 ` Josef Bacik
2021-07-30 0:13 ` Al Viro
2021-07-30 6:08 ` NeilBrown
2021-08-13 1:45 ` [PATCH] VFS/BTRFS/NFSD: provide more unique inode number for btrfs export NeilBrown
2021-08-13 14:55 ` Josef Bacik
2021-08-15 7:39 ` Goffredo Baroncelli
2021-08-15 19:35 ` Roman Mamedov
2021-08-15 21:03 ` Goffredo Baroncelli
2021-08-15 21:53 ` NeilBrown
2021-08-17 19:34 ` Goffredo Baroncelli
2021-08-17 21:39 ` NeilBrown
2021-08-18 17:24 ` Goffredo Baroncelli
2021-08-15 22:17 ` NeilBrown
2021-08-19 8:01 ` Amir Goldstein
2021-08-20 3:21 ` NeilBrown
2021-08-20 6:23 ` Amir Goldstein
2021-08-23 4:05 ` [PATCH v2] BTRFS/NFSD: " NeilBrown
2021-08-18 14:54 ` [PATCH] VFS/BTRFS/NFSD: " Wang Yugui
2021-08-18 21:46 ` NeilBrown
2021-08-19 2:19 ` Zygo Blaxell
2021-08-20 2:54 ` NeilBrown
2021-08-22 19:29 ` Zygo Blaxell
2021-08-23 5:51 ` NeilBrown
2021-08-23 23:22 ` NeilBrown [this message]
2021-08-25 2:06 ` Zygo Blaxell
2021-08-23 0:57 ` Wang Yugui
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