kernel/git/stable/linux.git/drivers/scsi/sd.h, branch linux-3.2.y

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

2016-04-30T22:05:22+00:00

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 [bwh: Backported to 3.2: - logical_to_sectors() is a new function - Adjust context] Signed-off-by: Ben Hutchings

sd: fix array cache flushing bug causing performance problems

2013-07-27T04:34:19+00:00

commit 39c60a0948cc06139e2fbfe084f83cb7e7deae3b upstream. 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 Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings

[SCSI] sd: remove arbitrary SD_MAX_DISKS namespace limit

2011-10-30T08:58:11+00:00

There is no reason to limit the SCSI disk namespace to sdXXX. Add new error messages to sd_probe() in the unlikely event that either ida_get_new() or sd_format_disk_name() fail. Signed-off-by: Dave Kleikamp Signed-off-by: James Bottomley

[SCSI] sd: Logical Block Provisioning update

2011-03-14T23:37:34+00:00

SBC3r26 contains many changes to the Logical Block Provisioning interfaces (formerly known as Thin Provisioning ditto). This patch implements support for both the old and new schemes using the same heuristic as before (whether the LBP VPD page is present). The new code also allows the provisioning mode (i.e. choice of command) to be overridden on a per-device basis via sysfs. Two additional modes are supported in this version: - WRITE SAME(10) with the UNMAP bit set - WRITE SAME(10) without the UNMAP bit set. This allows us to support devices that predate the TP/LBP enhancements in SBC3 and which work by way zero-detection Switching between modes has been consolidated in a helper function that also updates the block layer topology according to the limitations of the chosen command. I experimented with trying WRITE SAME(16) if UNMAP fails, WRITE SAME(10) if WRITE SAME(16) fails, etc. but found several devices that got cranky. So for now we'll disable discard if one of the commands fail. The user still has the option of selecting a different mode in sysfs. Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley

[SCSI] sd: implement sd_check_events()

2011-01-14T15:17:34+00:00

Replace sd_media_change() with sd_check_events(). * Move media removed logic into set_media_not_present() and media_not_present() and set sdev->changed iff an existing media is removed or the device indicates UNIT_ATTENTION. * Make sd_check_events() sets sdev->changed if previously missing media becomes present. * Event is reported only if sdev->changed is set. This makes media presence event reported if scsi_disk->media_present actually changed or the device indicated UNIT_ATTENTION. For backward compatibility, SDEV_EVT_MEDIA_CHANGE is generated each time sd_check_events() detects media change event. [jejb: fix boot failure] Signed-off-by: Tejun Heo Acked-by: Jens Axboe Signed-off-by: James Bottomley

[SCSI] sd: Fix overflow with big physical blocks

2010-10-11T22:33:20+00:00

The hw_sector_size variable could overflow if a device reported huge physical blocks. Switch to the more accurate physical_block_size terminology and make sure we use an unsigned int to match the range permitted by READ CAPACITY(16). Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley

[SCSI] sd: Update thin provisioning support

2010-09-17T17:07:55+00:00

Add support for the Thin Provisioning VPD page and use the TPU and TPWS bits to switch between UNMAP and WRITE SAME(16) for discards. If no TP VPD page is present we fall back to old scheme where the max descriptor count combined with the max lba count are used trigger UNMAP. Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley

[SCSI] scsi/block: increase flush/sync timeout

2010-09-05T17:57:04+00:00

We have been seeing the flush request timeout with a wide range of hardware from tgt+iser to FC targets from a major vendor. After discussions about if the value should be configurable and what the best value should be, this patch just increases the flush/sync cache timeout to 1 minute. 2 minutes was determined to be too long, and making it configurable was troublesome for users. This patch was made over Linus's tree. It is not made over scsi-misc or scsi-rc-fixes, because Linus's had block layer changes that my patch was built over. Signed-off-by: Mike Christie Acked-by: Jens Axboe Signed-off-by: James Bottomley

scsi/sd: remove big kernel lock

2010-08-07T16:26:08+00:00

Every user of the BKL in the sd driver is the result of the pushdown from the block layer into the open/close/ioctl functions. The only place that used to rely on the BKL is the sdkp->openers variable, which gets converted into an atomic_t. Nothing else seems to rely on the BKL, since the functions do not touch global data without holding another lock, and the open/close functions are still protected from concurrent execution using the bdev->bd_mutex. Signed-off-by: Arnd Bergmann Cc: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe

[SCSI] sd: WRITE SAME(16) / UNMAP support

2009-12-10T14:54:15+00:00

Implement a function for handling discard requests that sends either WRITE SAME(16) or UNMAP(10) depending on parameters indicated by the device in the block limits VPD. Extract unmap constraints and report them to the block layer. Based in part by a patch by Christoph Hellwig . Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley