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  1. 11 4月, 2015 1 次提交
    • J
      sd, mmc, virtio_blk, string_helpers: fix block size units · b9f28d86
      由 James Bottomley 提交于 
      The current string_get_size() overflows when the device size goes over
2^64 bytes because the string helper routine computes the suffix from
the size in bytes.  However, the entirety of Linux thinks in terms of
blocks, not bytes, so this will artificially induce an overflow on very
large devices.  Fix this by making the function string_get_size() take
blocks and the block size instead of bytes.  This should allow us to
keep working until the current SCSI standard overflows.

Also fix virtio_blk and mmc (both of which were also artificially
multiplying by the block size to pass a byte side to string_get_size()).

The mathematics of this is pretty simple:  we're taking a product of
size in blocks (S) and block size (B) and trying to re-express this in
exponential form: S*B = R*N^E (where N, the exponent is either 1000 or
1024) and R < N.  Mathematically, S = RS*N^ES and B=RB*N^EB, so if RS*RB
< N it's easy to see that S*B = RS*RB*N^(ES+EB).  However, if RS*BS > N,
we can see that this can be re-expressed as RS*BS = R*N (where R =
RS*BS/N < N) so the whole exponent becomes R*N^(ES+EB+1)

[jejb: fix incorrect 32 bit do_div spotted by kbuild test robot <fengguang.wu@intel.com>]
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>
      b9f28d86
  3. 19 3月, 2015 1 次提交
  5. 02 2月, 2015 1 次提交
  7. 09 1月, 2015 1 次提交
  9. 30 12月, 2014 1 次提交
  11. 25 11月, 2014 3 次提交
  13. 12 11月, 2014 6 次提交
  15. 05 10月, 2014 1 次提交
    • M
      block: disable entropy contributions for nonrot devices · b277da0a
      由 Mike Snitzer 提交于 
      Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.

Historically, all block devices have automatically made entropy
contributions.  But as previously stated in commit e2e1a148 ("block: add
sysfs knob for turning off disk entropy contributions"):
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    - Calling add_disk_randomness() has a lot of overhead.

There are more reliable sources for randomness than non-rotational block
devices.  From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      b277da0a
  17. 01 10月, 2014 1 次提交
  19. 16 9月, 2014 2 次提交
  21. 26 7月, 2014 3 次提交
  23. 18 7月, 2014 12 次提交
  25. 01 7月, 2014 1 次提交
  27. 19 5月, 2014 2 次提交
    • D
      sd: medium access timeout counter fails to reset · 2a863ba8
      由 David Jeffery 提交于 
      There is an error with the medium access timeout feature of the sd driver. The
sdkp->medium_access_timed_out value is reset to zero in sd_done() in the wrong
place.  Currently it is reset to zero only when a command returns sense data.
This can result in cases where the medium access check falsely triggers from
timed out commands which are hours or days apart.

For example, an I/O command times out and is aborted.  It then retries and
succeeds.  But with no sense data generated and returned, the
medium_access_timed_out value is not reset.  If no sd command returns sense
data, then the next command to time out (however far in time from the first
failure) will trigger the medium access timeout and put the device offline.

The resetting of sdkp->medium_access_timed_out should occur before the check
for sense data.

To reproduce using scsi_debug, use SCSI_DEBUG_OPT_TIMEOUT or
SCSI_DEBUG_OPT_MAC_TIMEOUT to force an I/O command to timeout.  Then, remove
the opt value so the I/O will succeed on retry.  Perform more I/O as desired.
Finally, repeat the process to make a new I/O command time out.  Without the
patch, the device will be marked offline even though many I/O commands have
succeeded between the 2 instances of timed out commands.
Signed-off-by: NDavid Jeffery <djeffery@redhat.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
      2a863ba8
    • C
      scsi: reintroduce scsi_driver.init_command · a1b73fc1
      由 Christoph Hellwig 提交于 
      Instead of letting the ULD play games with the prep_fn move back to
the model of a central prep_fn with a callback to the ULD.  This
already cleans up and shortens the code by itself, and will be required
to properly support blk-mq in the SCSI midlayer.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NNicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
      a1b73fc1
  29. 17 4月, 2014 1 次提交
  31. 16 4月, 2014 1 次提交
    • J
      block: remove struct request buffer member · b4f42e28
      由 Jens Axboe 提交于 
      This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.

Convert old style drivers to just use bio_data().

For the discard payload use case, just reference the page
in the bio.
Signed-off-by: NJens Axboe <axboe@fb.com>
      b4f42e28
  33. 11 4月, 2014 1 次提交
    • D
      scsi: async sd resume · 3c31b52f
      由 Dan Williams 提交于 
      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 <len.brown@intel.com>
Cc: Phillip Susi <psusi@ubuntu.com>
[alan: bug fix and clean up suggestion]
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Suggested-by: NTodd Brandt <todd.e.brandt@linux.intel.com>
[djbw: kick all resume work to the async queue]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      3c31b52f
  35. 27 3月, 2014 1 次提交