linux-toradex.git/block, branch v4.9.17

block: allow WRITE_SAME commands with the SG_IO ioctl

2017-03-22T11:43:38+00:00

[ Upstream commit 25cdb64510644f3e854d502d69c73f21c6df88a9 ]

The WRITE_SAME commands are not present in the blk_default_cmd_filter
write_ok list, and thus are failed with -EPERM when the SG_IO ioctl()
is executed without CAP_SYS_RAWIO capability (e.g., unprivileged users).
[ sg_io() -> blk_fill_sghdr_rq() > blk_verify_command() -> -EPERM ]

The problem can be reproduced with the sg_write_same command

  # sg_write_same --num 1 --xferlen 512 /dev/sda
  #

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_same --num 1 --xferlen 512 /dev/sda'
    Write same: pass through os error: Operation not permitted
  #

For comparison, the WRITE_VERIFY command does not observe this problem,
since it is in that list:

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_verify --num 1 --ilen 512 --lba 0 /dev/sda'
  #

So, this patch adds the WRITE_SAME commands to the list, in order
for the SG_IO ioctl to finish successfully:

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_same --num 1 --xferlen 512 /dev/sda'
  #

That case happens to be exercised by QEMU KVM guests with 'scsi-block' devices
(qemu "-device scsi-block" [1], libvirt "" [2]),
which employs the SG_IO ioctl() and runs as an unprivileged user (libvirt-qemu).

In that scenario, when a filesystem (e.g., ext4) performs its zero-out calls,
which are translated to write-same calls in the guest kernel, and then into
SG_IO ioctls to the host kernel, SCSI I/O errors may be observed in the guest:

  [...] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
  [...] sd 0:0:0:0: [sda] tag#0 Sense Key : Aborted Command [current]
  [...] sd 0:0:0:0: [sda] tag#0 Add. Sense: I/O process terminated
  [...] sd 0:0:0:0: [sda] tag#0 CDB: Write Same(10) 41 00 01 04 e0 78 00 00 08 00
  [...] blk_update_request: I/O error, dev sda, sector 17096824

Links:
[1] http://git.qemu.org/?p=qemu.git;a=commit;h=336a6915bc7089fb20fea4ba99972ad9a97c5f52
[2] https://libvirt.org/formatdomain.html#elementsDisks (see 'disk' -> 'device')

Signed-off-by: Mauricio Faria de Oliveira 
Signed-off-by: Brahadambal Srinivasan 
Reported-by: Manjunatha H R 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

blk-mq: Always schedule hctx->next_cpu

2017-01-19T19:18:07+00:00

commit c02ebfdddbafa9a6a0f52fbd715e6bfa229af9d3 upstream.

Commit 0e87e58bf60e ("blk-mq: improve warning for running a queue on the
wrong CPU") attempts to avoid triggering the WARN_ON in
__blk_mq_run_hw_queue when the expected CPU is dead.  Problem is, in the
last batch execution before round robin, blk_mq_hctx_next_cpu can
schedule a dead CPU and also update next_cpu to the next alive CPU in
the mask, which will trigger the WARN_ON despite the previous
workaround.

The following patch fixes this scenario by always scheduling the value
in hctx->next_cpu.  This changes the moment when we round-robin the CPU
running the hctx, but it really doesn't matter, since it still executes
BLK_MQ_CPU_WORK_BATCH times in a row before switching to another CPU.

Fixes: 0e87e58bf60e ("blk-mq: improve warning for running a queue on the wrong CPU")
Signed-off-by: Gabriel Krisman Bertazi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: cfq_cpd_alloc() should use @gfp

2017-01-19T19:18:07+00:00

commit ebc4ff661fbe76781c6b16dfb7b754a5d5073f8e upstream.

cfq_cpd_alloc() which is the cpd_alloc_fn implementation for cfq was
incorrectly hard coding GFP_KERNEL instead of using the mask specified
through the @gfp parameter.  This currently doesn't cause any actual
issues because all current callers specify GFP_KERNEL.  Fix it.

Signed-off-by: Tejun Heo 
Reported-by: Dan Carpenter 
Fixes: e4a9bde9589f ("blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methods")
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

sg_write()/bsg_write() is not fit to be called under KERNEL_DS

2017-01-09T07:32:25+00:00

commit 128394eff343fc6d2f32172f03e24829539c5835 upstream.

Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those.  Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

blk-mq: Do not invoke .queue_rq() for a stopped queue

2017-01-06T09:40:15+00:00

commit bc27c01b5c46d3bfec42c96537c7a3fae0bb2cc4 upstream.

The meaning of the BLK_MQ_S_STOPPED flag is "do not call
.queue_rq()". Hence modify blk_mq_make_request() such that requests
are queued instead of issued if a queue has been stopped.

Reported-by: Ming Lei 
Signed-off-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

Don't feed anything but regular iovec's to blk_rq_map_user_iov

2016-12-07T16:23:35+00:00

In theory we could map other things, but there's a reason that function
is called "user_iov".  Using anything else (like splice can do) just
confuses it.

Reported-and-tested-by: Johannes Thumshirn 
Cc: Al Viro 
Signed-off-by: Linus Torvalds

blk-mq: update hardware and software queues for sleeping alloc

2016-10-27T15:56:03+00:00

If we end up sleeping due to running out of requests, we should
update the hardware and software queues in the map ctx structure.
Otherwise we could end up having rq->mq_ctx point to the pre-sleep
context, and risk corrupting ctx->rq_list since we'll be
grabbing the wrong lock when inserting the request.

Reported-by: Dave Jones 
Reported-by: Chris Mason 
Tested-by: Chris Mason 
Fixes: 63581af3f31e ("blk-mq: remove non-blocking pass in blk_mq_map_request")
Signed-off-by: Jens Axboe

block: flush: fix IO hang in case of flood fua req

2016-10-26T13:49:27+00:00

This patch fixes one issue reported by Kent, which can
be triggered in bcachefs over sata disk. Actually it
is a generic issue in block flush vs. blk-tag.

Cc: Christoph Hellwig 
Reported-by: Kent Overstreet 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

badblocks: badblocks_set/clear update unacked_exist

2016-10-21T21:45:47+00:00

When bandblocks_set acknowledges a range or badblocks_clear a range,
it's possible all badblocks are acknowledged. We should update
unacked_exist if this occurs.

Signed-off-by: Shaohua Li 
Reviewed-by: Tomasz Majchrzak 
Tested-by: Tomasz Majchrzak 
Signed-off-by: Jens Axboe

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2016-10-21T17:54:01+00:00

Pull block fixes from Jens Axboe:
 "A set of fixes that missed the merge window, mostly due to me being
  away around that time.

  Nothing major here, a mix of nvme cleanups and fixes, and one fix for
  the badblocks handling"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvmet: use symbolic constants for CNS values
  nvme: use symbolic constants for CNS values
  nvme.h: add an enum for cns values
  nvme.h: don't use uuid_be
  nvme.h: resync with nvme-cli
  nvme: Add tertiary number to NVME_VS
  nvme : Add sysfs entry for NVMe CMBs when appropriate
  nvme: don't schedule multiple resets
  nvme: Delete created IO queues on reset
  nvme: Stop probing a removed device
  badblocks: fix overlapping check for clearing