From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH 27/30] libxfs: work around do_div() not handling 32 bit numerators
Date: Mon, 4 Nov 2013 01:16:43 -0800 [thread overview]
Message-ID: <20131104091643.GG23564@infradead.org> (raw)
In-Reply-To: <1383107481-28937-28-git-send-email-david@fromorbit.com>
On Wed, Oct 30, 2013 at 03:31:18PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> The libxfs dquot buffer code uses do_div() with a 32 bit numerator.
> This gives incorrect results as do_div() passes the numerator by
> reference as a pointer to a 64 bit value. Hence it does the division
> using 32 bits of garbage gives the wrong result. The kernel code
> handles 32 bit numerators just fine, so this patch is a temporary
> workaround in the dquot buffer code until we fix do_div() to handle
> 32 bit numerators correctly.
The right fix is to simply stop using do_div here, both in kernel and
userspace.
>
> xfs_calc_dquots_per_chunk(
> struct xfs_mount *mp,
> unsigned int nbblks) /* basic block units */
> {
> - unsigned int ndquots;
> + uint64_t ndquots;
>
> ASSERT(nbblks > 0);
> ndquots = BBTOB(nbblks);
> do_div(ndquots, sizeof(xfs_dqblk_t));
>
> - return ndquots;
> + return (int)ndquots;
ndquots = BBTOB(nbblks) / sizeof(xfs_dqblk_t);
Also the current xfs_calc_dquots_per_chunk doesn't use the mp argument
anyway, but all callers do. I think in the end we'd want to take that
in from the calers end end up with a version that includes the
check from the quotainfo. But for getting userspace up and running my
above minimal version should do it.
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next prev parent reply other threads:[~2013-11-04 9:16 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-30 4:30 [PATCH 00/30 V3] xfsprogs: CRC write support for xfs_db Dave Chinner
2013-10-30 4:30 ` [PATCH 01/30] xfsprogs: fix automatic dependency generation Dave Chinner
2013-10-31 14:44 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 02/30] xfs: fix some minor sparse warnings Dave Chinner
2013-10-31 14:44 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 03/30] xfs: create a shared header file for format-related information Dave Chinner
2013-10-31 14:45 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 04/30] xfs: split dquot buffer operations out Dave Chinner
2013-10-31 14:45 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 05/30] xfs: decouple inode and bmap btree header files Dave Chinner
2013-10-31 14:45 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 06/30] libxfs: unify xfs_btree.c with kernel code Dave Chinner
2013-10-31 14:46 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 07/30] libxfs: bmap btree owner swap support Dave Chinner
2013-10-31 14:47 ` Christoph Hellwig
2013-10-30 4:30 ` [PATCH 08/30] libxfs: xfs_rtalloc.c becomes xfs_rtbitmap.c Dave Chinner
2013-10-31 14:48 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 09/30] libxfs: bring across inode buffer readahead verifier changes Dave Chinner
2013-10-31 14:48 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 10/30] libxfs: Minor cleanup and bug fix sync Dave Chinner
2013-10-31 14:48 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 11/30] xfs: remove newlines from strings passed to __xfs_printk Dave Chinner
2013-10-31 14:49 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 12/30] xfs: fix the wrong new_size/rnew_size at xfs_iext_realloc_direct() Dave Chinner
2013-10-31 14:49 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 13/30] xfs: fix node forward in xfs_node_toosmall Dave Chinner
2013-10-31 14:49 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 14/30] xfs: don't emit corruption noise on fs probes Dave Chinner
2013-10-31 14:49 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 15/30] db: separate out straight buffer IO from map based IO Dave Chinner
2013-10-31 14:56 ` Christoph Hellwig
2013-10-31 21:50 ` Dave Chinner
2013-11-01 12:51 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 16/30] db: rewrite bbmap to use xfs_buf_map Dave Chinner
2013-10-31 15:06 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 17/30] db: rewrite IO engine to use libxfs Dave Chinner
2013-10-31 15:10 ` Christoph Hellwig
2013-10-31 21:59 ` Dave Chinner
2013-10-30 4:31 ` [PATCH 18/30] db: introduce verifier support into set_cur Dave Chinner
2013-11-01 13:07 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 19/30] db: indicate if the CRC on a buffer is correct or not Dave Chinner
2013-11-01 13:09 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 20/30] db: verify and calculate inode CRCs Dave Chinner
2013-11-04 9:05 ` Christoph Hellwig
2013-11-05 0:18 ` Dave Chinner
2013-10-30 4:31 ` [PATCH 21/30] db: verify and calculate dquot CRCs Dave Chinner
2013-11-04 9:06 ` Christoph Hellwig
2013-11-05 0:25 ` Dave Chinner
2013-10-30 4:31 ` [PATCH 22/30] db: add a special directory buffer verifier Dave Chinner
2013-11-04 9:07 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 23/30] db: add a special attribute " Dave Chinner
2013-11-04 9:07 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 24/30] db: re-enable write support for v5 filesystems Dave Chinner
2013-11-04 9:07 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 25/30] libxfs: fix root inode handling inconsistencies Dave Chinner
2013-10-30 10:23 ` Christoph Hellwig
2013-10-30 21:59 ` Dave Chinner
2013-10-31 4:13 ` [PATCH 25/30 V2] " Dave Chinner
2013-10-31 15:00 ` Christoph Hellwig
2013-10-31 22:04 ` Dave Chinner
2013-11-01 13:03 ` Christoph Hellwig
2013-11-04 23:22 ` Dave Chinner
2013-11-05 9:05 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 26/30] xfs_db: avoid libxfs buffer lookup warnings Dave Chinner
2013-11-04 9:12 ` Christoph Hellwig
2013-11-05 0:52 ` Dave Chinner
2013-11-05 9:06 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 27/30] libxfs: work around do_div() not handling 32 bit numerators Dave Chinner
2013-11-04 9:16 ` Christoph Hellwig [this message]
2013-11-05 1:55 ` Dave Chinner
2013-10-30 4:31 ` [PATCH 28/30] db: enable metadump on CRC filesystems Dave Chinner
2013-11-04 9:18 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 29/30] xfs: support larger inode clusters on v5 filesystems Dave Chinner
2013-11-04 9:18 ` Christoph Hellwig
2013-10-30 4:31 ` [PATCH 30/30] xfsprogs: kill experimental warnings for " Dave Chinner
2013-11-04 9:19 ` Christoph Hellwig
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