This re-introduces commit 2b14290078,
which was reverted due to the regression it caused by commit
fca082c9f1.
That regression was not root-caused by the original commit, it was just
uncovered by it, and the real fix was done by Alan Stern in commit
580da34847 ("Fix USB storage hang on
command abort").
We can thus re-introduce the change that was confirmed by Alan Jenkins
to be still required by his odd card reader.
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2b14290078, since it
seems to break some other USB storage devices (at least a JMicron USB to
ATA bridge). As such, while it apparently fixes some cardreaders, it
would need to be made conditional on the exact reader it fixes in order
to avoid causing regressions.
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The last_sector_bug flag was added to work around a bug in certain usb
cardreaders, where they would crash if a multiple sector read included the
last sector. The original implementation avoids this by e.g. splitting an 8
sector read which includes the last sector into a 7 sector read, and a single
sector read for the last sector. The flag is enabled for all USB devices.
This revealed a second bug in other usb cardreaders, which crash when they
get a multiple sector read which stops 1 sector short of the last sector.
Affected hardware includes the Kingston "MobileLite" external USB cardreader
and the internal USB cardreader on the Asus EeePC.
Extend the last_sector_bug workaround to ensure that any access which touches
the last 8 hardware sectors of the device is a single sector long. Requests
are shrunk as necessary to meet this constraint.
This gives us a safety margin against potential unknown or future bugs
affecting multi-sector access to the end of the device. The two known bugs
only affect the last 2 sectors. However, they suggest that these devices
are prone to fencepost errors and that multi-sector access to the end of the
device is not well tested. Popular OS's use multi-sector accesses, but they
rarely read the last few sectors. Linux (with udev & vol_id) automatically
reads sectors from the end of the device on insertion. It is assumed that
single sector accesses are more thoroughly tested during development.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Support for controllers and disks that implement DIF protection
information:
- During command preparation the RDPROTECT/WRPROTECT must be set
correctly if the target has DIF enabled.
- READ(6) and WRITE(6) are not supported when DIF is on.
- The controller must be told how to handle the I/O via the
protection operation field in scsi_cmnd.
- Refactor the I/O completion code that extracts failed LBA from the
returned sense data and handle DIF failures correctly.
- sd_dif.c implements the functions required to prepare and complete
requests with protection information attached.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If a disk is formatted with protection information (Inquiry bit
PROTECT=1) it is required to support Read Capacity(16). Force use of
the 16-bit command in this case and extract the P_TYPE field which
indicates whether the disk is formatted using DIF Type 1, 2 or 3.
The ATO (App Tag Own) bit in the Control Mode Page indicates whether
the storage device or the initiator own the contents of the
DIF application tag.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Christoph objected to having sd.h in include/scsi since it is internal
to the sd driver. Move it to drivers/scsi/sd.h.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Linus Torvalds
Alan Jenkins
Martin K. Petersen