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[1/2] dm-mpath: Enable hw_handler_params to take effect if hw_handler is the same between new and old

Message ID 1479971509-6320-1-git-send-email-tang.junhui@zte.com.cn (mailing list archive)
State Deferred, archived
Delegated to: Mike Snitzer
Headers show

Commit Message

tang.junhui@zte.com.cn Nov. 24, 2016, 7:11 a.m. UTC 
From: "tang.junhui" <tang.junhui@zte.com.cn>

If the hardware handle which a device has already attached is the same
with m->hw_handler_name, m->hw_handler_params should not be ignored, but
be enabled to take effect.

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
---
 drivers/md/dm-mpath.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

Comments

Mike Snitzer Nov. 28, 2016, 9:23 p.m. UTC | #1 
On Thu, Nov 24 2016 at  2:11am -0500,
tang.junhui@zte.com.cn <tang.junhui@zte.com.cn> wrote:

> From: "tang.junhui" <tang.junhui@zte.com.cn>
> 
> If the hardware handle which a device has already attached is the same
> with m->hw_handler_name, m->hw_handler_params should not be ignored, but
> be enabled to take effect.
> 
> Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>

I tweaked this a little bit and staged it for 4.10, see:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-4.10&id=1422b33eda2ffbc70eb11163bf7ac1e59ebba222

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diff mbox

Patch

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0caab4b..b1aba63 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -849,19 +849,23 @@  static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
 retain:
 		attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
 		if (attached_handler_name) {
+			/* clear any hw_handler_params associated with
+			 * m->hw_handler_params if a different handler has
+			 * already been attached.
+			 */
+			if(!m->hw_handler_name || strcmp(attached_handler_name, m->hw_handler_name))
+			{
+				kfree(m->hw_handler_params);
+				m->hw_handler_params = NULL;
+			}
 			/*
 			 * Reset hw_handler_name to match the attached handler
-			 * and clear any hw_handler_params associated with the
-			 * ignored handler.
 			 *
 			 * NB. This modifies the table line to show the actual
 			 * handler instead of the original table passed in.
 			 */
 			kfree(m->hw_handler_name);
 			m->hw_handler_name = attached_handler_name;
-
-			kfree(m->hw_handler_params);
-			m->hw_handler_params = NULL;
 		}
 	}