On Sun, 2005-12-25 at 16:28 +0200, George Zhim wrote:
> > This is not true, actually. They do share the struct file and since that is
> > where the current position lives, the current position WILL be affected.
> > That's why if parent and child both have a log file open (from before fork)
> > and write to it, output from BOTH will be there, mixed together.
>
> but if, after fork, one of them (either the child or the father)
> closes the file,
> how will it still stay available to the second one ?
Reference counting.
A sys_close() ends up executing the following
(sys_close->filp_close->fput):
if (atomic_dec_and_test(&file->f_count))
__fput(file);
So the struct file is not discarded until the last reference is closed.
--
fm
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