diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-05-19 00:03:07 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-06-01 00:27:38 -0700 |
| commit | 4cc987eaff9144182cde88d6d132420c28d3f81b (patch) | |
| tree | 15cf7d432599e1e09446462968ef01c4d10a087e /drivers/target/sbp | |
| parent | adf653f92f38e80a78bb77e912d49bcc8055330f (diff) | |
| download | linux-4cc987eaff9144182cde88d6d132420c28d3f81b.tar.bz2 | |
target: Drop lun_sep_lock for se_lun->lun_se_dev RCU usage
With se_port and t10_alua_tg_pt_gp_member being absored into se_lun,
there is no need for an extra lock to protect se_lun->lun_se_dev
assignment.
This patch also converts backend drivers to use call_rcu() release
to allow any se_device readers to complete. The call_rcu() instead
of kfree_rcu() is required here because se_device is embedded into
the backend driver specific structure.
Also, convert se_lun->lun_stats to use atomic_long_t within the
target_complete_ok_work() completion callback, and add FIXME for
transport_lookup_tmr_lun() with se_lun->lun_ref.
Finally, update sbp_update_unit_directory() special case usage with
proper rcu_dereference_raw() and configfs symlink comment.
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Chris Boot <bootc@bootc.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/sbp')
| -rw-r--r-- | drivers/target/sbp/sbp_target.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c index 47fb12fbaf47..28e3adf1eb85 100644 --- a/drivers/target/sbp/sbp_target.c +++ b/drivers/target/sbp/sbp_target.c @@ -1905,8 +1905,11 @@ static int sbp_update_unit_directory(struct sbp_tport *tport) hlist_for_each_entry_rcu(lun, &tport->tpg->se_tpg.tpg_lun_hlist, link) { struct se_device *dev; int type; - - dev = lun->lun_se_dev; + /* + * rcu_dereference_raw protected by se_lun->lun_group symlink + * reference to se_device->dev_group. + */ + dev = rcu_dereference_raw(lun->lun_se_dev); type = dev->transport->get_device_type(dev); /* logical_unit_number */ |