diff mbox series

scsi: make "access_state" sysfs attribute always visible

Message ID 20220127141351.30706-1-mwilck@suse.com
State New
Headers show
Series scsi: make "access_state" sysfs attribute always visible | expand

Commit Message

Martin Wilck Jan. 27, 2022, 2:13 p.m. UTC 
From: Martin Wilck <mwilck@suse.com>

If a SCSI device handler module is loaded after some SCSI devices
have already been probed (e.g. via request_module() by dm-multipath),
the "access_state" and "preferred_path" sysfs attributes remain invisible for
these devices, although the handler is attached and live. The reason is
that the visibility is only checked when the sysfs attribute group is
first created. This results in an inconsistent user experience depending
on the load order of SCSI low-level drivers vs. device handler modules.

This patch changes user space API: attempting to read the "access_state"
or "preferred_path" attributes will now result in -EINVAL rather than
-ENODEV for devices that have no device handler, and tests for the existence
of these attributes will have a different result.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_sysfs.c | 8 --------
 1 file changed, 8 deletions(-)

Comments

Martin K. Petersen Feb. 8, 2022, 4:07 a.m. UTC | #1 
> If a SCSI device handler module is loaded after some SCSI devices have
> already been probed (e.g. via request_module() by dm-multipath), the
> "access_state" and "preferred_path" sysfs attributes remain invisible
> for these devices, although the handler is attached and live. The
> reason is that the visibility is only checked when the sysfs attribute
> group is first created. This results in an inconsistent user
> experience depending on the load order of SCSI low-level drivers
> vs. device handler modules.
>
> This patch changes user space API: attempting to read the
> "access_state" or "preferred_path" attributes will now result in
> -EINVAL rather than -ENODEV for devices that have no device handler,
> and tests for the existence of these attributes will have a different
> result.

Applied to 5.18/scsi-staging, thanks!
Martin K. Petersen Feb. 11, 2022, 11:25 p.m. UTC | #2 
On Thu, 27 Jan 2022 15:13:51 +0100, mwilck@suse.com wrote:

> From: Martin Wilck <mwilck@suse.com>
> 
> If a SCSI device handler module is loaded after some SCSI devices
> have already been probed (e.g. via request_module() by dm-multipath),
> the "access_state" and "preferred_path" sysfs attributes remain invisible for
> these devices, although the handler is attached and live. The reason is
> that the visibility is only checked when the sysfs attribute group is
> first created. This results in an inconsistent user experience depending
> on the load order of SCSI low-level drivers vs. device handler modules.
> 
> [...]

Applied to 5.18/scsi-queue, thanks!

[1/1] scsi: make "access_state" sysfs attribute always visible
      https://git.kernel.org/mkp/scsi/c/7cddf7e8d1e8
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index f1e0c131b77c..226a50944c00 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1228,14 +1228,6 @@  static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
 	    !sdev->host->hostt->change_queue_depth)
 		return 0;
 
-#ifdef CONFIG_SCSI_DH
-	if (attr == &dev_attr_access_state.attr &&
-	    !sdev->handler)
-		return 0;
-	if (attr == &dev_attr_preferred_path.attr &&
-	    !sdev->handler)
-		return 0;
-#endif
 	return attr->mode;
 }