Messages in this thread | | | Date | Sun, 27 Jan 2008 21:13:45 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] [8/18] BKL-removal: Remove BKL from remote_llseek |
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On Mon, 28 Jan 2008 05:38:25 +0100 Andi Kleen <ak@suse.de> wrote:
> On Monday 28 January 2008 05:13:09 Trond Myklebust wrote: > > > > On Mon, 2008-01-28 at 03:58 +0100, Andi Kleen wrote: > > > The problem is that it's not a race in who gets to do its thing first, but a > > > parallel reader can actually see a corrupted value from the two independent > > > words on 32bit (e.g. during a 4GB). And this could actually completely corrupt > > > f_pos when it happens with two racing relative seeks or read/write()s > > > > > > I would consider that a bug. > > > > I disagree. The corruption occurs because this isn't a situation that is > > allowed by either POSIX or SUSv2/v3. Exactly what spec are you referring > > to here? > > No specific spec, just general quality of implementation.
I completely agree. If one thread writes A and another writes B then the kernel should record either A or B, not ((A & 0xffffffff00000000) | (B & 0xffffffff))
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