kernel.git/drivers/scsi/ses.c, branch linux-4.4.y

scsi: ses: Fix unsigned comparison with less than zero

2021-10-17T08:04:44Z

[ Upstream commit dd689ed5aa905daf4ba4c99319a52aad6ea0a796 ] Fix the following coccicheck warning: ./drivers/scsi/ses.c:137:10-16: WARNING: Unsigned expression compared with zero: result > 0. Link: https://lore.kernel.org/r/1632477113-90378-1-git-send-email-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: ses: don't get power status of SES device slot on probe

2018-03-22T08:23:24Z

[ Upstream commit 75106523f39751390b5789b36ee1d213b3af1945 ] The commit 08024885a2a3 ("ses: Add power_status to SES device slot") introduced the 'power_status' attribute to enclosure components and the associated callbacks. There are 2 callbacks available to get the power status of a device: 1) ses_get_power_status() for 'struct enclosure_component_callbacks' 2) get_component_power_status() for the sysfs device attribute (these are available for kernel-space and user-space, respectively.) However, despite both methods being available to get power status on demand, that commit also introduced a call to get power status in ses_enclosure_data_process(). This dramatically increased the total probe time for SCSI devices on larger configurations, because ses_enclosure_data_process() is called several times during the SCSI devices probe and loops over the component devices (but that is another problem, another patch). That results in a tremendous continuous hammering of SCSI Receive Diagnostics commands to the enclosure-services device, which does delay the total probe time for the SCSI devices __significantly__: Originally, ~34 minutes on a system attached to ~170 disks: [ 9214.490703] mpt3sas version 13.100.00.00 loaded ... [11256.580231] scsi 17:0:177:0: qdepth(16), tagged(1), simple(0), ordered(0), scsi_level(6), cmd_que(1) With this patch, it decreased to ~2.5 minutes -- a 13.6x faster [ 1002.992533] mpt3sas version 13.100.00.00 loaded ... [ 1151.978831] scsi 11:0:177:0: qdepth(16), tagged(1), simple(0), ordered(0), scsi_level(6), cmd_que(1) Back to the commit discussion.. on the ses_get_power_status() call introduced in ses_enclosure_data_process(): impact of removing it. That may possibly be in place to initialize the power status value on device probe. However, those 2 functions available to retrieve that value _do_ automatically refresh/update it. So the potential benefit would be a direct access of the 'power_status' field which does not use the callbacks... But the only reader of 'struct enclosure_component::power_status' is the get_component_power_status() callback for sysfs attribute, and it _does_ check for and call the .get_power_status callback, (which indeed is defined and implemented by that commit), so the power status value is, again, automatically updated. So, the remaining potential for a direct/non-callback access to the power_status attribute would be out-of-tree modules -- well, for those, if they are for whatever reason interested in values that are set during device probe and not up-to-date by the time they need it.. well, that would be curious. Well, to handle that more properly, set the initial power state value to '-1' (i.e., uninitialized) instead of '1' (power 'on'), and check for it in that callback which may do an direct access to the field value _if_ a callback function is not defined. Signed-off-by: Mauricio Faria de Oliveira Fixes: 08024885a2a3 ("ses: Add power_status to SES device slot") Reviewed-by: Dan Williams Reviewed-by: Song Liu Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ses: fix additional element traversal bug

2015-12-11T19:05:57Z

KASAN found that our additional element processing scripts drop off the end of the VPD page into unallocated space. The reason is that not every element has additional information but our traversal routines think they do, leading to them expecting far more additional information than is present. Fix this by adding a gate to the traversal routine so that it only processes elements that are expected to have additional information (list is in SES-2 section 6.1.13.1: Additional Element Status diagnostic page overview) Reported-by: Pavel Tikhomirov Tested-by: Pavel Tikhomirov Cc: stable@vger.kernel.org Signed-off-by: James Bottomley

ses: Fix problems with simple enclosures

2015-12-10T16:14:03Z

Simple enclosure implementations (mostly USB) are allowed to return only page 8 to every diagnostic query. That really confuses our implementation because we assume the return is the page we asked for and end up doing incorrect offsets based on bogus information leading to accesses outside of allocated ranges. Fix that by checking the page code of the return and giving an error if it isn't the one we asked for. This should fix reported bugs with USB storage by simply refusing to attach to enclosures that behave like this. It's also good defensive practise now that we're starting to see more USB enclosures. Reported-by: Andrea Gelmini Cc: stable@vger.kernel.org Reviewed-by: Ewan D. Milne Reviewed-by: Tomas Henzl Signed-off-by: James Bottomley

ses: Add power_status to SES device slot

2015-01-09T14:44:19Z

Add power_status to SES device slot, so we can power on/off the HDDs behind the enclosure. Check firmware status in ses_set_* before sending control pages to firmware. Signed-off-by: Song Liu Acked-by: Dan Williams Reviewed-by: Jens Axboe Cc: Hannes Reinecke Signed-off-by: Christoph Hellwig

ses: add reliable slot attribute

2015-01-09T14:44:19Z

The name provided by firmware is in a vendor specific format, publish the slot number to have a reliable mechanism for identifying slots across firmware implementations. If the enclosure does not provide a slot number fallback to the component number which is guaranteed unique, and usually mirrors the slot number. Cleaned up the unused ses_component.desc in the process. Signed-off-by: Dan Williams Signed-off-by: Song Liu Reviewed-by: Jens Axboe Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig

ses: add enclosure logical id

2015-01-09T14:44:18Z

Export the NAA logical id for the enclosure. This is optionally available from the sas_transport_class, but it is really a property of the enclosure. Signed-off-by: Dan Williams Signed-off-by: Song Liu Reviewed-by: Jens Axboe Cc: Hannes Reinecke Signed-off-by: Christoph Hellwig

ses: generate KOBJ_CHANGE on enclosure attach

2015-01-09T14:44:18Z

In support of a /dev/disk/by-slot populated with data from the enclosure and ses modules udev needs notification when the new interface files/links are available. Otherwise, any udev rules specified for the disk cannot assume that the enclosure topology has settled. Signed-off-by: Dan Williams Signed-off-by: Song Liu Reviewed-by: Jens Axboe Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig

ses: close potential registration race

2015-01-09T14:44:17Z

The slot and address fields have a small window of instability when userspace can read them before initialization. Separate enclosure_component allocation from registration. Signed-off-by: Dan Williams Signed-off-by: Song Liu Reviewed-by: Jens Axboe Cc: Hannes Reinecke Signed-off-by: Christoph Hellwig

scsi: remove scsi_driver owner field

2014-11-24T19:01:28Z

The driver core driver structure has grown an owner field and now requires it to be set for all modular drivers. Set it up for all scsi_driver instances and get rid of the now superflous scsi_driver owner field. Signed-off-by: Christoph Hellwig Reported-by: Shane M Seymour Reviewed-by: Ewan D. Milne