linux.git/drivers/scsi/sd.c, branch v3.15

Merge branch 'async-scsi-resume' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci

2014-04-12T00:23:52+00:00

Pull async SCSI resume support from Dan Williams:
 "Allow disks and other devices to resume in parallel.

  This provides a tangible speed up for a non-esoteric use case (laptop
  resume):

    https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach"

* 'async-scsi-resume' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci:
  scsi: async sd resume

scsi: async sd resume

2014-04-10T22:30:35+00:00

async_schedule() sd resume work to allow disks and other devices to
resume in parallel.

This moves the entirety of scsi_device resume to an async context to
ensure that scsi_device_resume() remains ordered with respect to the
completion of the start/stop command.  For the duration of the resume,
new command submissions (that do not originate from the scsi-core) will
be deferred (BLKPREP_DEFER).

It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container
of these operations.  Like scsi_sd_probe_domain it is flushed at
sd_remove() time to ensure async ops do not continue past the
end-of-life of the sdev.  The implementation explicitly refrains from
reusing scsi_sd_probe_domain directly for this purpose as it is flushed
at the end of dpm_resume(), potentially defeating some of the benefit.
Given sdevs are quiesced it is permissible for these resume operations
to bleed past the async_synchronize_full() calls made by the driver
core.

We defer the resolution of which pm callback to call until
scsi_dev_type_{suspend|resume} time and guarantee that the callback
parameter is never NULL.  With this in place the type of resume
operation is encoded in the async function identifier.

There is a concern that async resume could trigger PSU overload.  In the
enterprise, storage enclosures enforce staggered spin-up regardless of
what the kernel does making async scanning safe by default.  Outside of
that context a user can disable asynchronous scanning via a kernel
command line or CONFIG_SCSI_SCAN_ASYNC.  Honor that setting when
deciding whether to do resume asynchronously.

Inspired by Todd's analysis and initial proposal [2]:
https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach

Cc: Len Brown 
Cc: Phillip Susi 
[alan: bug fix and clean up suggestion]
Acked-by: Alan Stern 
Suggested-by: Todd Brandt 
[djbw: kick all resume work to the async queue]
Signed-off-by: Dan Williams

[SCSI] sd: Quiesce mode sense error messages

2014-03-27T15:26:33+00:00

Messages about discovered disk properties are only printed once unless
they are found to have changed. Errors encountered during mode sense,
however, are printed every time we revalidate.

Quiesce mode sense errors so they are only printed during the first
scan.

[jejb: checkpatch fixes]
Bugzilla: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=733565
Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] sd: don't fail if the device doesn't recognize SYNCHRONIZE CACHE

2014-03-15T17:19:22+00:00

Evidently some wacky USB-ATA bridges don't recognize the SYNCHRONIZE
CACHE command, as shown in this email thread:

	http://marc.info/?t=138978356200002&r=1&w=2

The fact that we can't tell them to drain their caches shouldn't
prevent the system from going into suspend.  Therefore sd_sync_cache()
shouldn't return an error if the device replies with an Invalid
Command ASC.

Signed-off-by: Alan Stern 
Reported-by: Sven Neumann 
Tested-by: Daniel Mack 
CC: 
Signed-off-by: James Bottomley

Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block

2014-01-30T19:19:05+00:00

Pull core block IO changes from Jens Axboe:
 "The major piece in here is the immutable bio_ve series from Kent, the
  rest is fairly minor.  It was supposed to go in last round, but
  various issues pushed it to this release instead.  The pull request
  contains:

   - Various smaller blk-mq fixes from different folks.  Nothing major
     here, just minor fixes and cleanups.

   - Fix for a memory leak in the error path in the block ioctl code
     from Christian Engelmayer.

   - Header export fix from CaiZhiyong.

   - Finally the immutable biovec changes from Kent Overstreet.  This
     enables some nice future work on making arbitrarily sized bios
     possible, and splitting more efficient.  Related fixes to immutable
     bio_vecs:

        - dm-cache immutable fixup from Mike Snitzer.
        - btrfs immutable fixup from Muthu Kumar.

  - bio-integrity fix from Nic Bellinger, which is also going to stable"

* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
  xtensa: fixup simdisk driver to work with immutable bio_vecs
  block/blk-mq-cpu.c: use hotcpu_notifier()
  blk-mq: for_each_* macro correctness
  block: Fix memory leak in rw_copy_check_uvector() handling
  bio-integrity: Fix bio_integrity_verify segment start bug
  block: remove unrelated header files and export symbol
  blk-mq: uses page->list incorrectly
  blk-mq: use __smp_call_function_single directly
  btrfs: fix missing increment of bi_remaining
  Revert "block: Warn and free bio if bi_end_io is not set"
  block: Warn and free bio if bi_end_io is not set
  blk-mq: fix initializing request's start time
  block: blk-mq: don't export blk_mq_free_queue()
  block: blk-mq: make blk_sync_queue support mq
  block: blk-mq: support draining mq queue
  dm cache: increment bi_remaining when bi_end_io is restored
  block: fixup for generic bio chaining
  block: Really silence spurious compiler warnings
  block: Silence spurious compiler warnings
  block: Kill bio_pair_split()
  ...

Merge tag 'v3.13-rc6' into for-3.14/core

2013-12-31T16:51:02+00:00

Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.

Fixup merge issues related to the immutable biovec changes.

Signed-off-by: Jens Axboe 

Conflicts:
	block/blk-flush.c
	fs/btrfs/check-integrity.c
	fs/btrfs/extent_io.c
	fs/btrfs/scrub.c
	fs/logfs/dev_bdev.c

[SCSI] sd: Do not call do_div() with a 64-bit divisor

2013-12-19T15:39:03+00:00

do_div() is meant for divisions of 64-bit number by 32-bit numbers.
Passing 64-bit divisor types caused issues in the past on 32-bit platforms,
cfr. commit ea077b1b96e073eac5c3c5590529e964767fc5f7 ("m68k: Truncate base
in do_div()").

As scsi_device.sector_size is unsigned (int), factor should be unsigned
int, too.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: James Bottomley

[SCSI] Fix erratic device offline during EH

2013-12-19T15:39:02+00:00

Commit 18a4d0a22ed6c54b67af7718c305cd010f09ddf8
(Handle disk devices which can not process medium access commands)
was introduced to offline any device which cannot process medium
access commands.
However, commit 3eef6257de48ff84a5d98ca533685df8a3beaeb8
(Reduce error recovery time by reducing use of TURs) reduced
the number of TURs by sending it only on the first failing
command, which might or might not be a medium access command.
So in combination this results in an erratic device offlining
during EH; if the command where the TUR was sent upon happens
to be a medium access command the device will be set offline,
if not everything proceeds as normal.

This patch moves the check to the final test, eliminating
this problem.

Signed-off-by: Hannes Reinecke 
Signed-off-by: James Bottomley

[SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers

2013-11-29T04:48:39+00:00

Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: Martin K. Petersen 
Cc: stable@kernel.org
Signed-off-by: James Bottomley

block: Convert bio_iovec() to bvec_iter

2013-11-24T06:33:49+00:00

For immutable biovecs, we'll be introducing a new bio_iovec() that uses
our new bvec iterator to construct a biovec, taking into account
bvec_iter->bi_bvec_done - this patch updates existing users for the new
usage.

Some of the existing users really do need a pointer into the bvec array
- those uses are all going to be removed, but we'll need the
functionality from immutable to remove them - so for now rename the
existing bio_iovec() -> __bio_iovec(), and it'll be removed in a couple
patches.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: "Ed L. Cashin" 
Cc: Alasdair Kergon 
Cc: dm-devel@redhat.com
Cc: "James E.J. Bottomley"