Messages in this thread | | | Date | Thu, 7 Jun 2007 23:10:42 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 001 of 2] Fix read/truncate race. |
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On Fri, 8 Jun 2007 12:48:48 +1000 Neil Brown <neilb@suse.de> wrote:
> The following patch will remove the extra seqlock except when we > actually need it and remove the extra arithmetic - but I haven't > tested it or reviewed it properly. I can do that if you think it is > the right direction.
Yes, the optimisation is valid and looks useful.
> ./mm/filemap.c | 34 ++++++++++++++++++++++++++++------
It didn't apply - your tree seems different from mine.
> + * > + * NOTE: This access of inode->i_size is not protected > + * and if there is a concurrent update on a 32bit machine, > + * it could return the wrong value. This could only be a problem > + * if i_size has actually changed to a smaller value before the > + * page became uptodate, and at this point it still has a smaller > + * value, but due to a race while reading, it appears unchanged. > + * The chances of this happening are so small and the consequence > + * sufficiently minor, that the cost of the seqlock seems > + * not to be justified.
please consider incorporating scripts/checkpatch.pl into your patch preparation toolchain.
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