From: Dave Chinner <david@fromorbit.com>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 3/5] xfs: rewrite xchk_inode_is_allocated to work properly
Date: Tue, 8 Aug 2023 17:14:46 +1000 [thread overview]
Message-ID: <ZNHrZoBjTRj4JX/u@dread.disaster.area> (raw)
In-Reply-To: <169049625753.922264.11707952061753226050.stgit@frogsfrogsfrogs>
On Thu, Jul 27, 2023 at 03:31:03PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
>
> Back in the mists of time[1], I proposed this function to assist the
> inode btree scrubbers in checking the inode btree contents against the
> allocation state of the inode records. The original version performed a
> direct lookup in the inode cache and returned the allocation status if
> the cached inode hadn't been reused and wasn't in an intermediate state.
> Brian thought it would be better to use the usual iget/irele mechanisms,
> so that was changed for the final version.
>
> Unfortunately, this hasn't aged well -- the IGET_INCORE flag only has
> one user and clutters up the regular iget path, which makes it hard to
> reason about how it actually works. Worse yet, the inode inactivation
> series silently broke it because iget won't return inodes that are
> anywhere in the inactivation machinery, even though the caller is
> already required to prevent inode allocation and freeing. Inodes in the
> inactivation machinery are still allocated, but the current code's
> interactions with the iget code prevent us from being able to say that.
>
> Now that I understand the inode lifecycle better than I did in early
> 2017, I now realize that as long as the cached inode hasn't been reused
> and isn't actively being reclaimed, it's safe to access the i_mode field
> (with the AGI, rcu, and i_flags locks held), and we don't need to worry
> about the inode being freed out from under us.
>
> Therefore, port the original version to modern code structure, which
> fixes the brokennes w.r.t. inactivation. In the next patch we'll remove
> IGET_INCORE since it's no longer necessary.
>
> [1] https://lore.kernel.org/linux-xfs/149643868294.23065.8094890990886436794.stgit@birch.djwong.org/
>
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Lotsa comments, nothing triggered me this time through :)
Reviewed-by: Dave Chinner <dchinner@redhat.com>
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2023-08-08 15:55 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-27 22:11 [MEGAPATCHSET v26] xfs: online repair, part of part 1 Darrick J. Wong
2023-07-27 22:18 ` [PATCHSET v26.0 0/9] xfs: fix online repair block reaping Darrick J. Wong
2023-07-27 22:21 ` [PATCH 1/9] xfs: cull repair code that will never get used Darrick J. Wong
2023-07-27 22:21 ` [PATCH 2/9] xfs: move the post-repair block reaping code to a separate file Darrick J. Wong
2023-07-27 22:22 ` [PATCH 3/9] xfs: only invalidate blocks if we're going to free them Darrick J. Wong
2023-07-27 22:22 ` [PATCH 4/9] xfs: only allow reaping of per-AG blocks in xrep_reap_extents Darrick J. Wong
2023-07-27 22:22 ` [PATCH 5/9] xfs: use deferred frees to reap old btree blocks Darrick J. Wong
2023-07-27 22:22 ` [PATCH 6/9] xfs: rearrange xrep_reap_block to make future code flow easier Darrick J. Wong
2023-07-27 22:23 ` [PATCH 7/9] xfs: allow scanning ranges of the buffer cache for live buffers Darrick J. Wong
2023-07-27 22:23 ` [PATCH 8/9] xfs: reap large AG metadata extents when possible Darrick J. Wong
2023-07-27 22:23 ` [PATCH 9/9] xfs: use per-AG bitmaps to reap unused AG metadata blocks during repair Darrick J. Wong
2023-08-07 6:19 ` [PATCHSET v26.0 0/9] xfs: fix online repair block reaping Dave Chinner
2023-08-08 0:40 ` Darrick J. Wong
2023-08-08 5:17 ` Dave Chinner
2023-08-09 23:17 ` Darrick J. Wong
2023-07-27 22:18 ` [PATCHSET v26.0 0/6] xfs: prepare repair for bulk loading Darrick J. Wong
2023-07-27 22:24 ` [PATCH 1/6] xfs: force all buffers to be written during btree bulk load Darrick J. Wong
2023-07-27 22:24 ` [PATCH 2/6] xfs: implement block reservation accounting for btrees we're staging Darrick J. Wong
2023-08-07 6:58 ` Dave Chinner
2023-08-08 1:08 ` Darrick J. Wong
2023-07-27 22:24 ` [PATCH 3/6] xfs: log EFIs for all btree blocks being used to stage a btree Darrick J. Wong
2023-08-07 8:41 ` Dave Chinner
2023-08-08 0:54 ` Darrick J. Wong
2023-08-08 6:11 ` Dave Chinner
2023-08-09 23:52 ` Darrick J. Wong
2023-08-10 20:36 ` Darrick J. Wong
2023-09-08 23:34 ` Darrick J. Wong
2023-07-27 22:24 ` [PATCH 4/6] xfs: add debug knobs to control btree bulk load slack factors Darrick J. Wong
2023-07-27 22:25 ` [PATCH 5/6] xfs: move btree bulkload record initialization to ->get_record implementations Darrick J. Wong
2023-07-27 22:25 ` [PATCH 6/6] xfs: constrain dirty buffers while formatting a staged btree Darrick J. Wong
2023-07-27 22:19 ` [PATCHSET v26.0 0/7] xfs: stage repair information in pageable memory Darrick J. Wong
2023-07-27 22:25 ` [PATCH 1/7] xfs: create a big array data structure Darrick J. Wong
2023-07-28 3:10 ` Matthew Wilcox
2023-07-28 4:39 ` Darrick J. Wong
2023-07-27 22:25 ` [PATCH 2/7] xfs: enable sorting of xfile-backed arrays Darrick J. Wong
2023-07-27 22:26 ` [PATCH 3/7] xfs: convert xfarray insertion sort to heapsort using scratchpad memory Darrick J. Wong
2023-07-27 22:26 ` [PATCH 4/7] xfs: teach xfile to pass back direct-map pages to caller Darrick J. Wong
2023-07-27 22:26 ` [PATCH 5/7] xfs: speed up xfarray sort by sorting xfile page contents directly Darrick J. Wong
2023-07-27 22:26 ` [PATCH 6/7] xfs: cache pages used for xfarray quicksort convergence Darrick J. Wong
2023-07-27 22:27 ` [PATCH 7/7] xfs: improve xfarray quicksort pivot Darrick J. Wong
2023-07-27 22:19 ` [PATCHSET v26.0 0/2] xfs: add usage counters for scrub Darrick J. Wong
2023-07-27 22:27 ` [PATCH 1/2] xfs: create scaffolding for creating debugfs entries Darrick J. Wong
2023-07-27 22:27 ` [PATCH 2/2] xfs: track usage statistics of online fsck Darrick J. Wong
2023-08-08 7:09 ` [PATCHSET v26.0 0/2] xfs: add usage counters for scrub Dave Chinner
2023-07-27 22:19 ` [PATCHSET v26.0 0/4] xfs: online scrubbing of realtime summary files Darrick J. Wong
2023-07-27 22:27 ` [PATCH 1/4] xfs: get our own reference to inodes that we want to scrub Darrick J. Wong
2023-07-27 22:28 ` [PATCH 2/4] xfs: wrap ilock/iunlock operations on sc->ip Darrick J. Wong
2023-07-27 22:28 ` [PATCH 3/4] xfs: move the realtime summary file scrubber to a separate source file Darrick J. Wong
2023-07-27 22:28 ` [PATCH 4/4] xfs: implement online scrubbing of rtsummary info Darrick J. Wong
2023-07-27 22:19 ` [PATCHSET v26.0 0/2] xfs: miscellaneous repair tweaks Darrick J. Wong
2023-07-27 22:28 ` [PATCH 1/2] xfs: always rescan allegedly healthy per-ag metadata after repair Darrick J. Wong
2023-07-27 22:29 ` [PATCH 2/2] xfs: allow the user to cancel repairs before we start writing Darrick J. Wong
2023-07-27 22:20 ` [PATCHSET v26.0 0/2] xfs: force rebuilding of metadata Darrick J. Wong
2023-07-27 22:29 ` [PATCH 1/2] xfs: don't complain about unfixed metadata when repairs were injected Darrick J. Wong
2023-07-27 22:29 ` [PATCH 2/2] xfs: allow userspace to rebuild metadata structures Darrick J. Wong
2023-07-27 22:20 ` [PATCHSET v26.0 0/2] xfs: fixes to the AGFL repair code Darrick J. Wong
2023-07-27 22:30 ` [PATCH 1/2] xfs: clear pagf_agflreset when repairing the AGFL Darrick J. Wong
2023-07-27 22:30 ` [PATCH 2/2] xfs: fix agf_fllast when repairing an empty AGFL Darrick J. Wong
2023-08-08 7:10 ` Dave Chinner
2023-07-27 22:20 ` [PATCHSET v26.0 0/5] xfs: online repair of AG btrees Darrick J. Wong
2023-07-27 22:30 ` [PATCH 1/5] xfs: repair free space btrees Darrick J. Wong
2023-07-27 22:30 ` [PATCH 2/5] xfs: hide xfs_inode_is_allocated in scrub common code Darrick J. Wong
2023-08-08 7:13 ` Dave Chinner
2023-07-27 22:31 ` [PATCH 3/5] xfs: rewrite xchk_inode_is_allocated to work properly Darrick J. Wong
2023-08-08 7:14 ` Dave Chinner [this message]
2023-07-27 22:31 ` [PATCH 4/5] xfs: repair inode btrees Darrick J. Wong
2023-07-27 22:31 ` [PATCH 5/5] xfs: repair refcount btrees Darrick J. Wong
2023-07-27 22:20 ` [PATCHSET v26.0 0/2] xfs: fixes for the block mapping checker Darrick J. Wong
2023-07-27 22:31 ` [PATCH 1/2] xfs: simplify returns in xchk_bmap Darrick J. Wong
2023-07-27 22:32 ` [PATCH 2/2] xfs: don't check reflink iflag state when checking cow fork Darrick J. Wong
2023-08-08 7:16 ` [PATCHSET v26.0 0/2] xfs: fixes for the block mapping checker Dave Chinner
2023-07-27 22:21 ` [PATCHSET v26.0 0/6] xfs: online repair of inodes and forks Darrick J. Wong
2023-07-27 22:32 ` [PATCH 1/6] xfs: disable online repair quota helpers when quota not enabled Darrick J. Wong
2023-07-27 22:32 ` [PATCH 2/6] xfs: try to attach dquots to files before repairing them Darrick J. Wong
2023-07-27 22:32 ` [PATCH 3/6] xfs: repair inode records Darrick J. Wong
2023-08-09 8:42 ` Dave Chinner
2023-08-10 0:43 ` Darrick J. Wong
2023-07-27 22:33 ` [PATCH 4/6] xfs: zap broken inode forks Darrick J. Wong
2023-07-27 22:33 ` [PATCH 5/6] xfs: abort directory parent scrub scans if we encounter a zapped directory Darrick J. Wong
2023-07-27 22:33 ` [PATCH 6/6] xfs: repair obviously broken inode modes Darrick J. Wong
2023-08-09 9:44 ` [PATCHSET v26.0 0/6] xfs: online repair of inodes and forks Dave Chinner
2023-08-10 0:45 ` Darrick J. Wong
2023-07-27 22:21 ` [PATCHSET v26.0 0/5] xfs: online repair of file fork mappings Darrick J. Wong
2023-07-27 22:33 ` [PATCH 1/5] xfs: reintroduce reaping of file metadata blocks to xrep_reap_extents Darrick J. Wong
2023-07-27 22:34 ` [PATCH 2/5] xfs: repair inode fork block mapping data structures Darrick J. Wong
2023-07-27 22:34 ` [PATCH 3/5] xfs: refactor repair forcing tests into a repair.c helper Darrick J. Wong
2023-07-27 22:34 ` [PATCH 4/5] xfs: create a ranged query function for refcount btrees Darrick J. Wong
2023-07-27 22:34 ` [PATCH 5/5] xfs: repair problems in CoW forks Darrick J. Wong
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