Re: file offset corruption on 32-bit machines?

From: Matthew Wilcox
Date: Thu Apr 10 2008 - 11:31:26 EST


On Thu, Apr 10, 2008 at 05:22:12PM +0200, Jan Kara wrote:
> You can get your inspiration in the implementation of i_size_read()
> and i_size_write() functions :). They deal with exactly the same problem.
> But in the case of f_pos, the number of readers and writers is balanced so
> maybe a spinlock would be fine as well...

It's not quite balanced -- see sys_getdents() for a counterexample.

i_size_read/write use a seqcount rather than a seqlock, but the
principle is the same.

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