My static checker complains that "devno" can be negative, meaning that
we read before the start of the loop.  I've looked at the code, and I
think the warning is right.  This come from /proc so it's root only or
it would be quite a quite a serious bug.  The call tree looks like this:

proc_scsi_write() <- gets id and channel from simple_strtoul()
-> scsi_add_single_device() <- calls shost->transportt->user_scan()
   -> ata_scsi_user_scan()
      -> ata_find_dev()
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # all versions at this point

Just wire up the generic TCG OPAL infrastructure to the SCSI disk driver
and the Security In/Out commands.

Note that I don't know of any actual SCSI disks that do support TCG OPAL,
but this is required to support ATA disks through libata.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

b1ffbf85 ("libata: Support for an ATA PASS-THROUGH(32) command.")
introduced an unused goto label.  Remove it.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NTejun Heo <tj@kernel.org>

SAT-4(SCSI/ATA Translation) supports for an ata pass-thru(32).
This patch will allow to translate an ata pass-thru(32) SCSI cmd
to an ATA cmd.
Signed-off-by: NMinwoo Im <dn3108@gmail.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

The function name used to be ata_scsiop_mode_select() but renamed to
ata_scsi_mode_select_xlat().  Update the comment accordingly.

tj: Minor commit desc update.
Signed-off-by: NMinwoo Im <dn3108@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Linus Torvalds changed the behavior of printks without KERN_<LEVEL>.

Convert the continuation prints to use pr_cont.

At the same time, convert the existing printks with KERN_<LEVEL> to
pr_<level>

Miscellanea:

o Coalesce a multiline format
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

This allows us to use the generic OPAL code with ATA devices.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

The libata documentation is now using ReST. Update references
to it to point to the new place.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Sphinx got confused with the markup identation:
	./drivers/ata/libata-scsi.c:3402: ERROR: Unexpected indentation.

No functional changes.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

The libata documentation is now using ReST. Update references
to it to point to the new place.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Sphinx got confused with the markup identation:
	./drivers/ata/libata-scsi.c:3402: ERROR: Unexpected indentation.

No functional changes.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

This was already disabled a while ago because it caused I/O errors,
and it's severly getting into the way of the discard / write zeroes
rework.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

The WRITE SAME to TRIM translation rewrites the DATA OUT buffer.  While
the SCSI code accomodates for this by passing a read-writable buffer
userspace applications don't cater for this behavior.  In fact it can
be used to rewrite e.g. a readonly file through mmap and should be
considered as a security fix.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

All but one caller want the decoded sense header, so offer the existing
__scsi_execute helper as the public scsi_execute API to simply the
callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This can be used to check for fs vs non-fs requests and basically
removes all knowledge of BLOCK_PC specific from the block layer,
as well as preparing for removing the cmd_type field in struct request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data.  To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

This reverts commit a234f739.

The commit tried to get rid of the shared global SCSI response buffer.
Unfortunately, it added blocking allocation to atomic path.  Revert it
for now.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>

Note of the emulated commands in the pageout/pagein path, so just do
a GFP_NOIO dynamic allocation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

No need to copy a zeroed buffer to the caller if the command is defined
to not have a response in the SCSI spec.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

We always need to call ->scsi_done after we've finished emulating a
command, so do it in a single place at the end of ata_scsi_simulate.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

It's always the scsi_done callback, and we can get at that easily
in the place where ->done is called.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

It's only used in libata-scsi.c, so move it closer to the users.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

We only need to look at 4 bytes of the inquiry response for ATAPI
devices.  Instead of using the global ata_scsi_rbuf just use a
a stack buffer.  Also factor the fixup into it's own little helper
function to make it more readable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

Previously, when the ata device was being initialized we were
probing for NCQ prio support by checking the identify information
and also checking the log page that holds information about ncq prio
support.

This caused an error on an Intel HBA so the code is now updated to
only probe for NCQ prio support when the sysfs variable controlling
NCQ prio support is enabled.

tj: Update formatting, switch to spin_[un]lock_irq() and update
    locking a bit, use REVALIDATE instead of RESET, and return -EIO
    instead of -EINVAL on config failure.
Signed-off-by: NAdam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

SCT Write Same support had been introduced with
commit 7b203094 ("libata: Add support for SCT Write Same")

Some problems, namely excessive userspace segfaults, had been reported at

  http://lkml.kernel.org/r/20160908192736.GA4356@gmail.com

This lead to commit 0ce1b18c ("libata: Some drives failing on
SCT Write Same") which strived to disable SCT Write Same on !ZAC devices.
Due to the way this was done and to the logic in sd_config_write_same(),
this didn't work for those devices that have
->max_ws_blocks > SD_MAX_WS10_BLOCKS: for these, ->no_write_same and
->max_write_same_sectors would still be non-zero,
but ->ws10 == ->ws16 == 0. This would cause sd_setup_write_same_cmnd() to
demultiplex REQ_OP_WRITE_SAME requests to WRITE_SAME, and these in turn
aren't supported by libata-scsi:

  EXT4-fs (dm-1): Delayed block allocation failed for inode 2625094 at
                  logical offset 2032 with max blocks 2 with error 121
  EXT4-fs (dm-1): This should not happen!! Data will be lost

121 == EREMOTEIO is what scsi_io_completion() asserts in case of
invalid opcodes.

Back to the original problem of userspace segfaults: this can be tracked
down to ata_format_sct_write_same() overwriting the input page. Sometimes,
this page is ZERO_PAGE(0) which ceases to be filled with zeros from that
point on. Since ZERO_PAGE(0) is used for userspace .bss mappings, code of
the following is doomed:

  static char *a = NULL; /* .bss */
  ...
  if (a)
    *a = 'a';

This problem is not solved by disabling SCT Write Same for !ZAC devices
only.

It can certainly be fixed, but the final release is quite close -- so
disable SCT Write Same for all ATA devices rather than introducing some
SCT key buffer allocation schemes at this point.

Fixes: 7b203094 ("libata: Add support for SCT Write Same")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

There's a typo in ata_gen_passthru_sense(), where the first byte
would be overwritten incorrectly later on.
Reported-by: NCharles Machalow <csm10495@gmail.com>
Signed-off-by: NHannes Reinecke <hare@suse.com>
Fixes: 11093cb1 ("libata-scsi: generate correct ATA pass-through sense")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: NTejun Heo <tj@kernel.org>

We previously had a check to see if the device has support for
prioritized ncq commands and a check to see if a device flag
is set, through a sysfs variable, in order to send a prioritized
command.

This patch only allows the sysfs variable to be set if the device
supports prioritized commands enabling one check in ata_build_rw_tf
in order to determine whether or not to send a prioritized command.

This patch depends on ata: ATA Command Priority Disabled By Default

tj: Minor subject and formatting updates.
Signed-off-by: NAdam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Add a sysfs entry to turn on priority information being passed
to a ATA device. By default this feature is turned off.

This patch depends on ata: Enabling ATA Command Priorities

tj: Renamed ncq_prio_on to ncq_prio_enable and removed trivial
    ata_ncq_prio_on() and open-coded the test.
Signed-off-by: NAdam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

This patch checks to see if an ATA device supports NCQ command priorities.
If so and the user has specified an iocontext that indicates
IO_PRIO_CLASS_RT then we build a tf with a high priority command.

This is done to improve the tail latency of commands that are high
priority by passing priority to the device.

tj: Removed trivial ata_ncq_prio_enabled() and open-coded the test.
Signed-off-by: NAdam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Restrict support SCT Write Same to devices which also support ZAC where
support is required.
Reported-by: NMike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Use non DMA write log when ATA_DFLAG_PIO is set.
Signed-off-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTejun Heo <tj@kernel.org>

Correct handling of devices with sector_size other that 512 bytes.

In the case of a 4Kn device sector_size it is possible to describe a much
larger DSM Trim than the current fixed default of 512 bytes.

This patch assumes the minimum descriptor is sector_size and fills out
the descriptor accordingly.

The ACS-2 specification is quite clear that the DSM command payload is
sized as number of 512 byte transfers so a 4Kn device will operate
correctly without this patch.
Signed-off-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Acked-by: NTejun Heo <tj@kernel.org>

SATA drives may support write same via SCT. This is useful
for setting the drive contents to a specific pattern (0's).

Translate a SCSI WRITE SAME 16 command to be either a DSM TRIM
command or an SCT Write Same command.

Based on the UNMAP flag:
  - When set translate to DSM TRIM
  - When not set translate to SCT Write Same
Signed-off-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTejun Heo <tj@kernel.org>

Safely overwriting the attached page to ATA format from the SCSI formatted
variant.
Signed-off-by: NShaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NTejun Heo <tj@kernel.org>

scsi_done() was called repeatedly and apparently because of that,
the kernel would call trace when we touch the Control mode page:

Call Trace:
 [<ffffffff812ea0d2>] dump_stack+0x63/0x81
 [<ffffffff81079cfb>] __warn+0xcb/0xf0
 [<ffffffff81079e2d>] warn_slowpath_null+0x1d/0x20
 [<ffffffffa00f51b0>] ata_eh_finish+0xe0/0xf0 [libata]
 [<ffffffffa00fb830>] sata_pmp_error_handler+0x640/0xa50 [libata]
 [<ffffffffa00470ed>] ahci_error_handler+0x1d/0x70 [libahci]
 [<ffffffffa00f55f0>] ata_scsi_port_error_handler+0x430/0x770 [libata]
 [<ffffffffa00eff8d>] ? ata_scsi_cmd_error_handler+0xdd/0x160 [libata]
 [<ffffffffa00f59d7>] ata_scsi_error+0xa7/0xf0 [libata]
 [<ffffffffa00913ba>] scsi_error_handler+0xaa/0x560 [scsi_mod]
 [<ffffffffa0091310>] ? scsi_eh_get_sense+0x180/0x180 [scsi_mod]
 [<ffffffff81098eb8>] kthread+0xd8/0xf0
 [<ffffffff815d913f>] ret_from_fork+0x1f/0x40
 [<ffffffff81098de0>] ? kthread_worker_fn+0x170/0x170
---[ end trace 8b7501047e928a17 ]---

Removed the unnecessary code and let ata_scsi_translate() do the job.

Also, since ata_mselect_control() has no ATA command to send to the
device, ata_scsi_mode_select_xlat() should return 1 for it, so that
ata_scsi_translate() will finish early to avoid ata_qc_issue().
Signed-off-by: NTom Yan <tom.ty89@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

ata_mselect_*() would initialize a char array for storing a copy of
the current mode page. However, char could be signed char. In that
case, bytes larger than 127 would be converted to negative number.

For example, 0xff from def_control_mpage[] would become -1. This
prevented ata_mselect_control() from working at all, since when it
did the read-only bits check, there would always be a mismatch.
Signed-off-by: NTom Yan <tom.ty89@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

`changeable` is the "version" of mode page requested by the user.
It will be less confusing/misleading if we do not check it
"together" with the setting bits of the drive.

Not to mention that we currently have ata_mselect_*() implemented
in a way that each of them will serve exclusively a particular bit
on each page. The old style will hence make the condition look even
more unnecessarily arcane if the ata_msense_*() is reflecting more
than one bit.
Signed-off-by: NTom Yan <tom.ty89@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

The reset_all variable name is misleading as this bit is also applicable to
open, close, and finish actions. So rename that variable to "all" and remove
the unnecessary mask operation that's already done earlier.
Signed-off-by: NDamien Le Moal <damien.lemoal@hgst.com>
[hch: split from the previous patch]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

The subcommand for NCQ NON-DATA must be specified in the feature
(low byte), not the high-order count byte.  Also make sure to properly
cast the all bit to a u16 before shiting it by 8 to avoid undefined
behavior.
Signed-off-by: NDamien Le Moal <damien.lemoal@hgst.com>
[hch: split the original patch into two, updated changelog]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

Include reporting options when translating REPORT ZONES commmand to
ATA NCQ, and make sure we only look at the actually specified bits
in the CDB for the options.
Signed-off-by: NDamien Le Moal <damien.lemoal@hgst.com>
[hch: update patch description]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTejun Heo <tj@kernel.org>