Messages in this thread | | | Date | Fri, 2 May 2008 16:41:00 +0100 | From | Al Viro <> | Subject | Re: [patch] fs: remove local variable copy of f_pos to enable thread-safe updates |
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On Fri, May 02, 2008 at 08:33:50AM -0700, Matti Linnanvuori wrote:
> File systems can be written so that implementations of read, lseek etc. > acquire a lock before using *pos, which precludes races. That was the > idea behind my patch. So, my patch does not necessarily cause races. > read instances can be racy in Linux now because there is no lock to > serialize read etc. system calls.
Oh, yes it does - current tree guarantees that variable passed to ->read() will not change under it, so any code that relied on that got broken.
And no, modifying every driver's ->read() is not going to be fun - it's not just filesystems.
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