When sd_init_command() get's a command with a unknown req_op() it crashes the
system via BUG().

This makes debugging the actual reason for the broken request cmd_flags pretty
hard as the system is down before it's able to write out debugging data on the
serial console or the trace buffer.

Change the BUG() to a WARN_ON() and return BLKPREP_KILL to fail gracefully and
return an I/O error to the producer of the request.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently a scsi device won't contribute to kernel randomness when it uses
blk-mq. Since we commonly use scsi on rotational device with blk-mq, it make
sense to keep contributing to kernel randomness in these cases. This is
especially important for virtual machines.

commit b5b6e8c8 ("scsi: virtio_scsi: fix IO hang caused by automatic irq
vector affinity") made all virtio-scsi device to use blk-mq, which does not
contribute to randomness today. So for a virtual machine only having
virtio-scsi disk (which is common), it will simple stop getting randomness
from its disks in today's implementation.

With this patch, if the above VM has rotational virtio-scsi device, then it
can still benefit from the entropy generated from the disk.
Reported-by: NXuewei Zhang <xueweiz@google.com>
Signed-off-by: NXuewei Zhang <xueweiz@google.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NMaciej Żenczykowski <maze@google.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allows us to remove an explicit spinlock.
Signed-off-by: NMatthew Wilcox <willy@infradead.org>

Currently these functions are implemented in the scsi layer, but their
actual place should be the block layer since T10-PI is a general data
integrity feature that is used in the nvme protocol as well. Also, use
the tuple size from the integrity profile since it may vary between
integrity types.
Suggested-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since blk_rq_bytes(req) returns req->__data_len, assigning that value to
req->__data_len is superfluous. Hence remove that assignment.

See also commit 5db44863 ("[SCSI] sd: Implement support for WRITE SAME").
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When evaluating a SCSI command's result using the field access macros,
check for equality of the fields and not if a specific bit is set.

This is a preparation patch, for reworking the results field in the
SCSI command.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

A drive being sanitized will return NOT READY / ASC 0x4 / ASCQ
0x1b ("LOGICAL UNIT NOT READY. SANITIZE IN PROGRESS").

Prevent spinning up the drive until this condition clears.

[mkp: tweaked commit message]
Signed-off-by: NMahesh Rajashekhara <mahesh.rajashekhara@microsemi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The USB storage glue sets the try_rc_10_first flag in an attempt to
avoid wedging poorly implemented legacy USB devices.

If the device capacity is too large to be expressed in the provided
response buffer field of READ CAPACITY(10), a well-behaved device will
set the reported capacity to 0xFFFFFFFF. We will then attempt to issue a
READ CAPACITY(16) to obtain the real capacity.

Since this part of the discovery logic is not covered by the first_scan
flag, a warning will be printed a couple of times times per revalidate
attempt if we upgrade from READ CAPACITY(10) to READ CAPACITY(16).

Remember that we have successfully issued READ CAPACITY(16) so we can
take the fast path on subsequent revalidate attempts.
Reported-by: NMenion <menion@gmail.com>
Reviewed-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch has been generated as follows:

for verb in set_unlocked clear_unlocked set clear; do
  replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
    $(git grep -lw queue_flag_${verb} drivers block/bsg*)
done

Except for protecting all queue flag changes with the queue lock
this patch does not change any functionality.

Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If the read-only flag is true on a SCSI disk, re-reading the partition
table sets the flag back to false.

To observe this bug, you can run:

1. blockdev --setro /dev/sda
2. blockdev --rereadpt /dev/sda
3. blockdev --getro /dev/sda

This commit reads the disk's old state and combines it with the device
disk-reported state rather than unconditionally marking it as RW.
Reported-by: NLi Ning <lining916740672@icloud.com>
Signed-off-by: NJeremy Cline <jeremy@jcline.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The block layer now handles zone write locking.

[mkp: removed SCMD_ZONE_WRITE_LOCK reference in scsi_debugfs]
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Avoid that scsi_show_rq() triggers a NULL pointer dereference if called
after sd_uninit_command(). Swap the NULL pointer assignment and the
mempool_free() call in sd_uninit_command() to make it less likely that
scsi_show_rq() triggers a use-after-free. Note: even with these changes
scsi_show_rq() can trigger a use-after-free but that's a lesser evil
than e.g. suppressing debug information for T10 PI Type 2 commands
completely. This patch fixes the following oops:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: scsi_format_opcode_name+0x1a/0x1c0
CPU: 1 PID: 1881 Comm: cat Not tainted 4.14.0-rc2.blk_mq_io_hang+ #516
Call Trace:
 __scsi_format_command+0x27/0xc0
 scsi_show_rq+0x5c/0xc0
 __blk_mq_debugfs_rq_show+0x116/0x130
 blk_mq_debugfs_rq_show+0xe/0x10
 seq_read+0xfe/0x3b0
 full_proxy_read+0x54/0x90
 __vfs_read+0x37/0x160
 vfs_read+0x96/0x130
 SyS_read+0x55/0xc0
 entry_SYSCALL_64_fastpath+0x1a/0xa5

[mkp: added Type 2]

Fixes: 0eebd005 ("scsi: Implement blk_mq_ops.show_rq()")
Reported-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

KERN_CONT is now required for continued printks(). Add it.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

/sys/class/scsi_disk/0:2:0:0/manage_start_stop can be changed to 0
unexpectly by writing an invalid string.
Signed-off-by: Nweiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

/sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0
unexpectedly by writing an invalid string such as the following:

echo asdf > /sys/class/scsi_disk/0:2:0:0/allow_restart
Signed-off-by: Nweiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

A user may lower the max_sectors_kb setting in sysfs to accommodate
certain workloads. Previously we would always set the max I/O size to
either the block layer default or the optional preferred I/O size
reported by the device.

Keep the current heuristics for the initial setting of max_sectors_kb.
For subsequent invocations, only update the current queue limit if it
exceeds the capabilities of the hardware.

Cc: <stable@vger.kernel.org>
Reported-by: NDon Brace <don.brace@microsemi.com>
Reviewed-by: NMartin Wilck <mwilck@suse.com>
Tested-by: NDon Brace <don.brace@microsemi.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

SBC-4 states:

  "A MAXIMUM UNMAP LBA COUNT field set to a non-zero value indicates the
   maximum number of LBAs that may be unmapped by an UNMAP command"

  "A MAXIMUM WRITE SAME LENGTH field set to a non-zero value indicates
   the maximum number of contiguous logical blocks that the device server
   allows to be unmapped or written in a single WRITE SAME command."

Despite the spec being clear on the topic, some devices incorrectly
expect WRITE SAME commands with the UNMAP bit set to be limited to the
value reported in MAXIMUM UNMAP LBA COUNT in the Block Limits VPD.

Implement a blacklist option that can be used to accommodate devices
with this behavior.

Cc: <stable@vger.kernel.org>
Reported-by: NBill Kuzeja <William.Kuzeja@stratus.com>
Reported-by: NEwan D. Milne <emilne@redhat.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Reporting a maximum number of blocks that is not aligned on the device
physical size would cause a large write same request to be split into
physically unaligned chunks by __blkdev_issue_write_zeroes() and
__blkdev_issue_write_same(), even if the caller of these functions took
care to align its request to physical sectors.

Make sure the maximum reported is aligned to the device physical block
size. This is only an optional optimization for regular disks, but this
is mandatory to avoid failure of large write same requests directed at
sequential write required zones of host-managed ZBC disks.

[mkp: tweaked commit message]
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

After series of changes around WRITE_SAME and UNMAP setup we ended up
with leftover unnecessary condition. Remove it.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

gd->minors has been set when call alloc_disk() in sd_probe.
Signed-off-by: Nweiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch avoids that gcc reports the following warning when
building with W=1:

drivers/scsi/sd.c:315:10: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
  if (val >= 0 && val <= T10_PI_TYPE3_PROTECTION)
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch avoids that smatch reports the following:

drivers/scsi/sd.c:3540: sd_suspend_common() warn: inconsistent indenting
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Before scsi_prep_fn() calls the ULP .init_command() callback
function it stores the SCSI command pointer in request.special.
This means that the SCpnt = rq->special assignments in the sd
and sr drivers assign a pointer to itself. Hence convert these
two assignment statements into warning statements.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Releasing a zone write lock only when the write commnand that acquired
the lock completes can cause deadlocks due to potential command
reordering if the lock owning request is requeued and not executed. This
problem exists only with the scsi-mq path as, unlike the legacy path,
requests are moved out of the dispatch queue before being prepared and
so before locking a zone for a write command.

Since sd_uninit_cmnd() is now always called when a request is requeued,
call sd_zbc_write_unlock_zone() from that function for write requests
that acquired a zone lock instead of from sd_done(). Acquisition of a zone
lock by a write command is indicated using the new command
flag SCMD_ZONE_WRITE_LOCK.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

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>

Avoid unnecessary snprintf() when formatting variables for display in
sysfs and switch to sysfs_match_string() for validating user input.
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Serializing SCSI device state changes avoids that two state changes can
occur concurrently, e.g. the state changes in scsi_target_block() and
__scsi_remove_device(). This serialization is essential to make patch
"Make __scsi_remove_device go straight from BLOCKED to DEL" work
reliably.

Enable this mechanism for all scsi_target_*block() callers but not for
the scsi_internal_device_unblock() calls from the mpt3sas driver because
that driver can call scsi_internal_device_unblock() from atomic context.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some external hard drives don't support the sync command even though the
hard drive has write cache enabled. In this case, upon suspend request,
sync cache failures are ignored if the error code in the sense header is
ILLEGAL_REQUEST. There's not much we can do for these drives, so we
shouldn't fail to suspend for this error case. The drive may stay
powered if that's the setup for the port it's plugged into.
Signed-off-by: NDerek Basehore <dbasehore@chromium.org>
Signed-off-by: NThierry Escande <thierry.escande@collabora.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For a zoned block device, sd_zbc_complete() handles zone write unlock on
completion of a REQ_OP_WRITE_ZEROES command but the zone write locking
is missing from sd_setup_write_zeroes_cmnd(). This patch fixes this
problem by locking the target zone of a REQ_OP_WRITE_ZEROES request.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

scsi_io_init() may fail, leaving a zone of a zoned block device locked.
Fix this by properly unlocking the write same request target zone if
scsi_io_init() fails.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Rename sd_zbc_setup_write_cmnd() to sd_zbc_write_lock_zone() to be clear
about what the function actually does. To be consistent, also rename
sd_zbc_cancel_write_cmnd() to sd_zbc_write_unlock_zone().

No functional change is introduced by this patch.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use a switch for the sense key, and remove two pointless variables that
are only used once.

[mkp: Added UNMAP comment and removed good_bytes based on comment from
Damien]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Re-shuffle the code to be more efficient by not initializing variables
upfront (i.e. do it only when necessary).  Also replace the do_div calls
with calls to sectors_to_logical().

No functional change is introduced by this patch.

[mkp: bytes_to_logical()]
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Fix argument names and description of function documentation comments.
No functional change is introduced by this patch.

[mkp: verbify]
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Separating discards and zeroout operations allows us to remove the LBPRZ
block zeroing constraints from discards and honor the device preferences
for UNMAP commands.

If supported by the device, we'll also choose UNMAP over one of the
WRITE SAME variants for discards.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that zeroout and discards are distinct operations we need to
separate the policy of choosing the appropriate command. Create a
zeroing_mode which can be one of:

write:			Zeroout assist not present, use regular WRITE
writesame:		Allow WRITE SAME(10/16) with a zeroed payload
writesame_16_unmap:	Allow WRITE SAME(16) with UNMAP
writesame_10_unmap:	Allow WRITE SAME(10) with UNMAP

The last two are conditional on the device being thin provisioned with
LBPRZ=1 and LBPWS=1 or LBPWS10=1 respectively.

Whether to set the UNMAP bit or not depends on the REQ_NOUNMAP flag. And
if none of the _unmap variants are supported, regular WRITE SAME will be
used if the device supports it.

The zeroout_mode is exported in sysfs and the detected mode for a given
device can be overridden using the string constants above.

With this change in place we can now issue WRITE SAME(16) with UNMAP set
for block zeroing applications that require hard guarantees and
logical_block_size granularity. And at the same time use the UNMAP
command with the device's preferred granulary and alignment for discard
operations.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Try to use a write same with unmap bit variant if the device supports it
and the caller allows for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Split sd_setup_discard_cmnd into one function per provisioning type.  While
this creates some very slight duplication of boilerplate code it keeps the
code modular for additions of new provisioning types, and for reusing the
write same functions for the upcoming scsi implementation of the Write Zeroes
operation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>