linux.git/drivers/usb/storage/usb.c, branch v4.13

usb-storage: fix deadlock involving host lock and scsi_done

2017-07-30T14:18:27+00:00

Christoph Hellwig says that since version 4.12, the kernel switched to
using blk-mq by default.  The old code used a softirq for handling
request completions, but blk-mq can handle completions in the caller's
context.  This may cause a problem for usb-storage, because it invokes
the ->scsi_done callback while holding the host lock, and the
completion routine sometimes tries to acquire the same lock (when
running the error handler, for example).

The consequence is that the existing code will sometimes deadlock upon
error completion of a SCSI command (with a lockdep warning).

This is easy enough to fix, since usb-storage doesn't really need to
hold the host lock while the callback runs.  It was simpler to write
it that way, but moving the call outside the locked region is pretty
easy and there's no downside.  That's what this patch does.

Signed-off-by: Alan Stern 
Reported-and-tested-by: Arthur Marsh 
CC: Christoph Hellwig 
CC: 
Signed-off-by: Greg Kroah-Hartman

USB: storage: refactor endpoint retrieval

2017-03-23T12:54:08+00:00

Use the new endpoint helpers to lookup the required bulk-in and bulk-out
endpoints and the (typically) optional interrupt-in endpoint.

Cc: usb-storage@lists.one-eyed-alien.net
Signed-off-by: Johan Hovold 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb: storage: drop freezer.h usage

2016-11-07T09:19:49+00:00

usb-storage does not use any freezer apis, so drop the inclusion of
freezer.h from the drivers/usb/storage/usb.c file.

Signed-off-by: Greg Kroah-Hartman

scsi: introduce a quirk for false cache reporting

2016-09-13T06:08:24+00:00

Some SATA to USB bridges fail to cooperate with some
drives resulting in no cache being present being reported
to the host. That causes the host to skip sending
a command to synchronize caches. That causes data loss
when the drive is powered down.

Signed-off-by: Oliver Neukum 
Reviewed-by: Martin K. Petersen 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb: storage: usb: don't print error when allocating urb fails

2016-08-15T13:54:27+00:00

kmalloc will print enough information in case of failure.

Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

usb: storage: fix runtime pm issue in usb_stor_probe2

2016-08-09T13:59:35+00:00

Since commit 71723f95463d "PM / runtime: print error when activating a
child to unactive parent" I see the following error message:

scsi host2: usb-storage 1-3:1.0
scsi host2: runtime PM trying to activate child device host2 but parent
	    (1-3:1.0) is not active

Digging into it it seems to be related to the problem described in the
commit message for cd998ded5c12 "i2c: designware: Prevent runtime
suspend during adapter registration" as scsi_add_host also calls
device_add and after the call to device_add the parent device is
suspended.

Fix this by using the approach from the mentioned commit and getting
the runtime pm reference before calling scsi_add_host.

Signed-off-by: Heiner Kallweit 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb: storage: fix multi-line comment style

2016-04-26T22:04:38+00:00

No functional changes here, just making sure our
storage driver uses a consistent multi-line comment
style.

Signed-off-by: Felipe Balbi 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: uas: Add a new NO_REPORT_LUNS quirk

2016-04-13T19:02:28+00:00

Add a new NO_REPORT_LUNS quirk and set it for Seagate drives with
an usb-id of: 0bc2:331a, as these will fail to respond to a
REPORT_LUNS command.

Cc: stable@vger.kernel.org
Reported-and-tested-by: David Webb 
Signed-off-by: Hans de Goede 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb: storage: fix module reference for scsi host

2015-05-10T14:03:50+00:00

While accessing a unusual usb storage (ums-alauda, ums-cypress, ...),
the module reference count is not incremented.  Because these drivers
allocate scsi hosts with usb_stor_host_template defined in usb-storage
module.  So these drivers always can be unloaded.

This fixes it by preparing scsi host template which is initialized
at module_init() for each ums-* driver.  In order to minimize the
difference in ums-* drivers, introduce module_usb_stor_driver() helper
macro which is same as module_usb_driver() except that it also
initializes scsi host template.

Signed-off-by: Akinobu Mita 
Cc: Vinayak Holikatti 
Cc: Dolev Raviv 
Cc: Sujit Reddy Thumma 
Cc: Subhash Jadavani 
Cc: Christoph Hellwig 
Cc: "James E.J. Bottomley" 
Cc: Matthew Dharm 
Cc: Greg Kroah-Hartman 
Cc: "David S. Miller" 
Cc: Hannes Reinecke 
Cc: linux-usb@vger.kernel.org
Cc: usb-storage@lists.one-eyed-alien.net
Cc: linux-scsi@vger.kernel.org
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

uas: Add US_FL_MAX_SECTORS_240 flag

2015-04-28T10:48:57+00:00

The usb-storage driver sets max_sectors = 240 in its scsi-host template,
for uas we do not want to do that for all devices, but testing has shown
that some devices need it.

This commit adds a US_FL_MAX_SECTORS_240 flag for such devices, and
implements support for it in uas.c, while at it it also adds support
for US_FL_MAX_SECTORS_64 to uas.c.

Cc: stable@vger.kernel.org # 3.16
Signed-off-by: Hans de Goede 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman