From: Christoph Hellwig <hch@infradead.org>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 3/8] xfs: don't trip over negative free space in xfs_reserve_blocks
Date: Thu, 21 Jun 2018 23:31:43 -0700 [thread overview]
Message-ID: <20180622063143.GC27254@infradead.org> (raw)
In-Reply-To: <152960588253.26246.18220681679037001885.stgit@magnolia>
On Thu, Jun 21, 2018 at 11:31:22AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> If we somehow end up with a filesystem that has fewer free blocks than
> the blocks set aside to avoid ENOSPC deadlocks, it's possible that the
> free space calculation in xfs_reserve_blocks will spit out a negative
> number (because percpu_counter_sum returns s64). We fail to notice
> this negative number and set fdblks_delta to it. Now we increment
> fdblocks(!) and the unsigned type of m_resblks means that we end up
> setting a ridiculously huge m_resblks reservation.
>
> Avoid this comedy of errors by detecting the negative free space and
> returning -ENOSPC.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2018-06-22 6:31 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-21 18:31 [PATCH 0/8] xfs-4.18: various fixes Darrick J. Wong
2018-06-21 18:31 ` [PATCH 1/8] xfs: allow empty transactions while frozen Darrick J. Wong
2018-06-22 6:18 ` Allison Henderson
2018-06-22 6:31 ` Christoph Hellwig
2018-06-21 18:31 ` [PATCH 2/8] xfs: fix fdblocks accounting w/ RMAPBT per-AG reservation Darrick J. Wong
2018-06-22 6:21 ` Allison Henderson
2018-06-21 18:31 ` [PATCH 3/8] xfs: don't trip over negative free space in xfs_reserve_blocks Darrick J. Wong
2018-06-22 6:31 ` Christoph Hellwig [this message]
2018-06-22 6:32 ` Allison Henderson
2018-06-21 18:31 ` [PATCH 4/8] xfs: don't allow insert-range to shift extents past the maximum offset Darrick J. Wong
2018-06-22 6:33 ` Allison Henderson
2018-06-22 6:39 ` Christoph Hellwig
2018-06-22 6:47 ` Darrick J. Wong
2018-06-22 21:21 ` [PATCH v2 " Darrick J. Wong
2018-06-23 6:47 ` Christoph Hellwig
2018-06-21 18:31 ` [PATCH 5/8] xfs: recheck reflink state after grabbing ILOCK_SHARED for a write Darrick J. Wong
2018-06-22 6:40 ` Christoph Hellwig
2018-06-21 18:31 ` [PATCH 6/8] xfs: fix uninitialized field in rtbitmap fsmap backend Darrick J. Wong
2018-06-22 6:37 ` Allison Henderson
2018-06-22 6:41 ` Christoph Hellwig
2018-06-22 6:47 ` Darrick J. Wong
2018-06-22 21:22 ` [PATCH v2 " Darrick J. Wong
2018-06-23 6:47 ` Christoph Hellwig
2018-06-21 18:31 ` [PATCH 7/8] xfs: fix off-by-one error in xfs_rtalloc_query_range Darrick J. Wong
2018-06-22 6:41 ` Christoph Hellwig
2018-06-22 6:41 ` Allison Henderson
2018-06-21 18:31 ` [PATCH 8/8] xfs: ensure post-EOF zeroing happens after zeroing part of a file Darrick J. Wong
2018-06-22 6:29 ` Christoph Hellwig
2018-06-22 6:49 ` Darrick J. Wong
2018-06-22 6:42 ` Allison Henderson
2018-06-22 6:21 ` [PATCH 9/8] xfs: check leaf attribute block freemap in verifier Darrick J. Wong
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