Add an option to only transfer half the data for every n-th command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>

This adds a module parameter to enable clustering.

Without enabling clustering support, the transfer length for read and
write scsi commands is limited upto 8MB when page size is 4KB and
sg_tablesize is 2048 (= SCSI_MAX_SG_CHAIN_SEGMENTS).  I would like to
test commands with more than that transfer length.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

This change ensures that concurrent device access including ramdisk
storage, protection info, and provisioning map by read, write, and
unmap commands are protected with atomic_rw spinlock.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Currently, clustering support for scsi_debug is disabled.  This is
because there are for_each_sg() loops which assume that each sg list
element is consisted with a single page.  But enabling clustering
support, each sg list element for scsi commands can be consisted with
multiple pages.

This replaces these for_each_sg() loops with sg mapping iterator which
is capable of handling each sg list element is consisted with multiple
pages.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

When resp_xdwriteread() can't allocate temporary buffer, it returns -1.
But the return value is used as scsi status code and -1 is not
interpreted as correct code.

target_core_mod has similar xdwriteread emulation code. So this mimics
what target_core_mod does for xdwriteread when running out of memory.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

It is unnecessary to increase dif_errors in dif_verify(), because the
caller will increment it when dif_verify() detects failure.

This bug was introduced by commit beb40ea42bd6 ("[SCSI] scsi_debug:
reduce duplication between prot_verify_read and prot_verify_write")

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

As pseudo_primary is only used in scsi_debug.c, it should be static.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Reading partially unwritten sectors generates a false positive logical
block reference tag check failure when DIF is enabled.

This bug is caused by missing ei_lba increment in loop of dif_verify()
when unwritten sector is skipped.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Instead of repeatedly calling driver_create_file() to create driver
attribute files, This achieves the same thing by constructing an array
of driver_attribute and setting it to bus_type->drv_groups.

This change simplifies both creation and destruction of the attribute
files, and also removes sparse warning caused by driver_attributes which
are unnecessarily declared as global.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Each member in data integrity field tuple is big-endian.  But the
endianness of the values being compared with these members are not
annotated.  So this fixes these sparse warnings.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>