Messages in this thread | | | Date | Thu, 4 Jun 2015 11:11:00 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] perf tools: avoid possible race condition in copyfile |
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* Milos Vyletel <milos@redhat.com> wrote:
> Use unique temporary files when copying to buildid dir to prevent races > in case multiple instances are trying to copy same file. This is done by > > - creating template in form <path>/.<filename>.XXXXXX where the suffix is > used by mkstemp() to create unique file > - change file mode > - copy content > - if successful link temp file to target file > - unlink temp file > > At this point the only file left at target path should be the desired > one either created by us or other instance if we raced. This should also > prevent not yet fully copied files to be visible to to other perf > instances that could try to parse them. > > On top of that slow_copyfile no longer needs to deal with file mode when > creating file since temporary file is already created and mode is set. > > Signed-off-by: Milos Vyletel <milos@redhat.com>
Ok, that looks nice!
Assuming it passes testing you can add my ack to it:
Acked-by: Ingo Molnar <mingo@kernel.org>
Is there any other place in tools/perf where we are using file locking or racy shared access to the same file(s)?
Thanks,
Ingo
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