As of RHEL 7.5 the mainline fops.iterate() method was added to
the file_operations structure and is correctly detected by the
configure script.
Normally this is what we want, but in order to maintain KABI
compatibility the RHEL change additionally does the following:
* Requires that callers intending to use this extended interface
set the FMODE_KABI_ITERATE flag on the file structure when
opening the directory.
* Adds the fops.iterate() method to the end of the structure,
without removing fops.readdir().
This change updates the configure check to ignore the RHEL 7.5+
variant of fops.iterate() when detected. Instead fallback to
the fops.readdir() interface which will be available.
Finally, add the 'zpl_' prefix to the directory context wrappers
to avoid colliding with the kernel provided symbols when both
the fops.iterate() and fops.readdir() are provided by the kernel.
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7460Closes#7463