kernel.git/drivers/scsi/sd.h, branch linux-4.5.y

sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes

2016-04-20T06:45:23Z

commit f08bb1e0dbdd0297258d0b8cd4dbfcc057e57b2a upstream. During revalidate we check whether device capacity has changed before we decide whether to output disk information or not. The check for old capacity failed to take into account that we scaled sdkp->capacity based on the reported logical block size. And therefore the capacity test would always fail for devices with sectors bigger than 512 bytes and we would print several copies of the same discovery information. Avoid scaling sdkp->capacity and instead adjust the value on the fly when setting the block device capacity and generating fake C/H/S geometry. Signed-off-by: Martin K. Petersen Reported-by: Hannes Reinecke Reviewed-by: Hannes Reinicke Reviewed-by: Ewan Milne Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

block/sd: Fix device-imposed transfer length limits

2015-11-26T02:38:58Z

Commit 4f258a46346c ("sd: Fix maximum I/O size for BLOCK_PC requests") had the unfortunate side-effect of removing an implicit clamp to BLK_DEF_MAX_SECTORS for REQ_TYPE_FS requests in the block layer code. This caused problems for some SMR drives. Debugging this issue revealed a few problems with the existing infrastructure since the block layer didn't know how to deal with device-imposed limits, only limits set by the I/O controller. - Introduce a new queue limit, max_dev_sectors, which is used by the ULD to signal the maximum sectors for a REQ_TYPE_FS request. - Ensure that max_dev_sectors is correctly stacked and taken into account when overriding max_sectors through sysfs. - Rework sd_read_block_limits() so it saves the max_xfer and opt_xfer values for later processing. - In sd_revalidate() set the queue's max_dev_sectors based on the MAXIMUM TRANSFER LENGTH value in the Block Limits VPD. If this value is not reported, fall back to a cap based on the CDB TRANSFER LENGTH field size. - In sd_revalidate(), use OPTIMAL TRANSFER LENGTH from the Block Limits VPD--if reported and sane--to signal the preferred device transfer size for FS requests. Otherwise use BLK_DEF_MAX_SECTORS. - blk_limits_max_hw_sectors() is no longer used and can be removed. Signed-off-by: Martin K. Petersen Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=93581 Reviewed-by: Christoph Hellwig Tested-by: sweeneygj@gmx.com Tested-by: Arzeets Tested-by: David Eisner Tested-by: Mario Kicherer Signed-off-by: Martin K. Petersen

scsi: introduce sdev_prefix_printk()

2014-11-12T10:15:57Z

Like scmd_printk(), but the device name is passed in as a string. Can be used by eg ULDs which do not have access to the scsi_cmnd structure. Signed-off-by: Hannes Reinecke Reviewed-by: Robert Elliott Signed-off-by: Christoph Hellwig

sd: Honor block layer integrity handling flags

2014-09-30T21:17:35Z

A set of flags introduced in the block layer enable better control over how protection information is handled. These flags are useful for both error injection and data recovery purposes. Checking can be enabled and disabled for controller and disk, and the guard tag format is now a per-I/O property. Update sd_protect_op to communicate the relevant information to the low-level device driver via a set of flags in scsi_cmnd. Signed-off-by: Martin K. Petersen Reviewed-by: Sagi Grimberg Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe

sd: Limit transfer length

2014-07-17T20:07:33Z

Until now the per-command transfer length has exclusively been gated by the max_sectors parameter in the scsi_host template. Given that the size of this parameter has been bumped to an unsigned int we have to be careful not to exceed the target device's capabilities. If the if the device specifies a Maximum Transfer Length in the Block Limits VPD we'll use that value. Otherwise we'll use 0xffffffff for devices that have use_16_for_rw set and 0xffff for the rest. We then combine the chosen disk limit with max_sectors in the host template. The smaller of the two will be used to set the max_hw_sectors queue limit. Signed-off-by: Martin K. Petersen Reviewed-by: Ewan D. Milne Signed-off-by: Christoph Hellwig

[SCSI] sd: Quiesce mode sense error messages

2014-03-27T15:26:33Z

Messages about discovered disk properties are only printed once unless they are found to have changed. Errors encountered during mode sense, however, are printed every time we revalidate. Quiesce mode sense errors so they are only printed during the first scan. [jejb: checkpatch fixes] Bugzilla: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=733565 Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley

[SCSI] Derive the FLUSH_TIMEOUT from the basic I/O timeout

2013-10-25T08:58:16Z

Rather than having a separate constant for specifying the timeout on FLUSH operations, use the basic I/O timeout value that is already configurable on a per target basis to derive the FLUSH timeout. Looking at the current definitions of these timeout values, the FLUSH operation is supposed to have a value that is twice the normal timeout value. This patch preserves this relationship while leveraging the flexibility of specifying the I/O timeout. Based on a prior patch by KY Srinivasan Reviewed-by: KY Srinivasan Signed-off-by: James Bottomley

[SCSI] sd: Update WRITE SAME heuristics

2013-06-27T00:56:18Z

SATA drives located behind a SAS controller would incorrectly receive WRITE SAME commands. Tweak the heuristics so that: - If REPORT SUPPORTED OPERATION CODES is provided we will use that to choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also fixes an issue with the old code which would issue WRITE SAME(10) despite the command not being whitelisted in REPORT SUPPORTED OPERATION CODES. - If REPORT SUPPORTED OPERATION CODES is not provided we will fall back to WRITE SAME(10) unless the device has an ATA Information VPD page. The assumption is that a SATL which is smart enough to implement WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES. To facilitate the new heuristics scsi_report_opcode() has been modified to so we can distinguish between "operation not supported" and "RSOC not supported". Reported-by: H. Peter Anvin Tested-by: Bernd Schubert Signed-off-by: Martin K. Petersen Cc: Signed-off-by: James Bottomley

[SCSI] sd: fix array cache flushing bug causing performance problems

2013-05-02T23:15:54Z

Some arrays synchronize their full non volatile cache when the sd driver sends a SYNCHRONIZE CACHE command. Unfortunately, they can have Terrabytes of this and we send a SYNCHRONIZE CACHE for every barrier if an array reports it has a writeback cache. This leads to massive slowdowns on journalled filesystems. The fix is to allow userspace to turn off the writeback cache setting as a temporary measure (i.e. without doing the MODE SELECT to write it back to the device), so even though the device reported it has a writeback cache, the user, knowing that the cache is non volatile and all they care about is filesystem correctness, can turn that bit off in the kernel and avoid the performance ruinous (and safety irrelevant) SYNCHRONIZE CACHE commands. The way you do this is add a 'temporary' prefix when performing the usual cache setting operations, so echo temporary write through > /sys/class/scsi_disk//cache_type Reported-by: Ric Wheeler Cc: Signed-off-by: James Bottomley

[SCSI] sd: Implement support for WRITE SAME

2012-11-14T06:45:42Z

Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk driver. - We set the default maximum to 0xFFFF because there are several devices out there that only support two-byte block counts even with WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK LIMITS VPD. - max_write_same_blocks can be overriden per-device basis in sysfs. - The UNMAP discovery heuristics remain unchanged but the discard limits are tweaked to match the "real" WRITE SAME commands. - In the error handling logic we now distinguish between WRITE SAME with and without UNMAP set. The discovery process heuristics are: - If the device reports a SCSI level of SPC-3 or greater we'll issue READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is supported. If that's the case we will use it. - If the device supports the block limits VPD and reports a MAXIMUM WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16). - Otherwise we will use WRITE SAME(10) unless the target LBA is beyond 0xFFFFFFFF or the block count exceeds 0xFFFF. - no_write_same is set for ATA, FireWire and USB. Signed-off-by: Martin K. Petersen Reviewed-by: Mike Snitzer Reviewed-by: Jeff Garzik Signed-off-by: James Bottomley