md/raid5-cache: Drop RCU usage of conf->log

The only place that uses RCU to access conf->log is in
r5l_log_disk_error(). This function is mostly used in the IO path
and once with mddev_lock() held in raid5_change_consistency_policy().

It is known that the IO will be suspended before the log is freed and
r5l_log_exit() is called with the mddev_lock() held.

This should mean that conf->log can not be freed while the function is
being called, so the RCU protection is not necessary. Drop the
rcu_read_lock() as well as the synchronize_rcu() and
rcu_assign_pointer() usage.

Signed-off-by: Logan Gunthorpe <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions