linux-toradex.git/drivers/md/dm-snap.c, branch v3.16-rc5

Merge tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2014-06-12T20:33:29+00:00

Pull device mapper updates from Mike Snitzer:
"This pull request is later than I'd have liked because I was waiting
for some performance data to help finally justify sending the
long-standing dm-crypt cpu scalability improvements upstream.

Unfortunately we came up short, so those dm-crypt changes will
continue to wait, but it seems we're not far off.

. Add dm_accept_partial_bio interface to DM core to allow DM targets
to only process a portion of a bio, the remainder being sent in the
next bio. This enables the old dm snapshot-origin target to only
split write bios on chunk boundaries, read bios are now sent to the
origin device unchanged.

. Add DM core support for disabling WRITE SAME if the underlying SCSI
layer disables it due to command failure.

. Reduce lock contention in DM's bio-prison.

. A few small cleanups and fixes to dm-thin and dm-era"

* tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm thin: update discard_granularity to reflect the thin-pool blocksize
dm bio prison: implement per bucket locking in the dm_bio_prison hash table
dm: remove symbol export for dm_set_device_limits
dm: disable WRITE SAME if it fails
dm era: check for a non-NULL metadata object before closing it
dm thin: return ENOSPC instead of EIO when error_if_no_space enabled
dm thin: cleanup noflush_work to use a proper completion
dm snapshot: do not split read bios sent to snapshot-origin target
dm snapshot: allocate a per-target structure for snapshot-origin target
dm: introduce dm_accept_partial_bio
dm: change sector_count member in clone_info from sector_t to unsigned

dm snapshot: do not split read bios sent to snapshot-origin target

2014-06-03T17:44:07+00:00

Change the snapshot-origin target so that only write bios are split on
chunk boundary.  Read bios are passed unchanged to the underlying
device, so they don't have to be split.

Later, we could change the target so that it accepts a larger write bio
if it spans an area that is completely covered by snapshot exceptions.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm snapshot: allocate a per-target structure for snapshot-origin target

2014-06-03T17:44:07+00:00

Allocate a per-target dm_origin structure.  This is a prerequisite for
the next commit ("dm snapshot: do not split read bios sent to
snapshot-origin target") which adds a new member to this structure.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

arch: Mass conversion of smp_mb__*()

2014-04-18T12:20:48+00:00

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra 
Acked-by: Paul E. McKenney 
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds 
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar

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()
  ...

dm snapshot: use GFP_KERNEL when initializing exceptions

2014-01-14T16:18:16+00:00

The list of initial exceptions is loaded in the target constructor.  We
are allowed to allocate memory with GFP_KERNEL at this point.  So,
change alloc_completed_exception to use GFP_KERNEL when being called
from the constructor.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

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

dm snapshot: avoid snapshot space leak on crash

2013-12-10T21:34:25+00:00

There is a possible leak of snapshot space in case of crash.

The reason for space leaking is that chunks in the snapshot device are
allocated sequentially, but they are finished (and stored in the metadata)
out of order, depending on the order in which copying finished.

For example, supposed that the metadata contains the following records
SUPERBLOCK
METADATA (blocks 0 ... 250)
DATA 0
DATA 1
DATA 2
...
DATA 250

Now suppose that you allocate 10 new data blocks 251-260. Suppose that
copying of these blocks finish out of order (block 260 finished first
and the block 251 finished last). Now, the snapshot device looks like
this:
SUPERBLOCK
METADATA (blocks 0 ... 250, 260, 259, 258, 257, 256)
DATA 0
DATA 1
DATA 2
...
DATA 250
DATA 251
DATA 252
DATA 253
DATA 254
DATA 255
METADATA (blocks 255, 254, 253, 252, 251)
DATA 256
DATA 257
DATA 258
DATA 259
DATA 260

Now, if the machine crashes after writing the first metadata block but
before writing the second metadata block, the space for areas DATA 250-255
is leaked, it contains no valid data and it will never be used in the
future.

This patch makes dm-snapshot complete exceptions in the same order they
were allocated, thus fixing this bug.

Note: when backporting this patch to the stable kernel, change the version
field in the following way:
* if version in the stable kernel is {1, 11, 1}, change it to {1, 12, 0}
* if version in the stable kernel is {1, 10, 0} or {1, 10, 1}, change it
  to {1, 10, 2}
Userspace reads the version to determine if the bug was fixed, so the
version change is needed.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org

block: Generic bio chaining

2013-11-24T06:33:56+00:00

This adds a generic mechanism for chaining bio completions. This is
going to be used for a bio_split() replacement, and it turns out to be
very useful in a fair amount of driver code - a fair number of drivers
were implementing this in their own roundabout ways, often painfully.

Note that this means it's no longer to call bio_endio() more than once
on the same bio! This can cause problems for drivers that save/restore
bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all
- in all but the simplest cases they'd be better off just cloning the
bio, and immutable biovecs is making bio cloning cheaper. But for now,
we add a bio_endio_nodec() for these cases.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe

block: Abstract out bvec iterator

2013-11-24T06:33:47+00:00

Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Geert Uytterhoeven 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "Ed L. Cashin" 
Cc: Nick Piggin 
Cc: Lars Ellenberg 
Cc: Jiri Kosina 
Cc: Matthew Wilcox 
Cc: Geoff Levand 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris 
Cc: Philip Kelleher 
Cc: Rusty Russell 
Cc: "Michael S. Tsirkin" 
Cc: Konrad Rzeszutek Wilk 
Cc: Jeremy Fitzhardinge 
Cc: Neil Brown 
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh 
Cc: Benny Halevy 
Cc: "James E.J. Bottomley" 
Cc: Greg Kroah-Hartman 
Cc: "Nicholas A. Bellinger" 
Cc: Alexander Viro 
Cc: Chris Mason 
Cc: "Theodore Ts'o" 
Cc: Andreas Dilger 
Cc: Jaegeuk Kim 
Cc: Steven Whitehouse 
Cc: Dave Kleikamp 
Cc: Joern Engel 
Cc: Prasad Joshi 
Cc: Trond Myklebust 
Cc: KONISHI Ryusuke 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Ben Myers 
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Len Brown 
Cc: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: Herton Ronaldo Krzesinski 
Cc: Ben Hutchings 
Cc: Andrew Morton 
Cc: Guo Chao 
Cc: Tejun Heo 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Wei Yongjun 
Cc: "Roger Pau Monné" 
Cc: Jan Beulich 
Cc: Stefano Stabellini 
Cc: Ian Campbell 
Cc: Sebastian Ott 
Cc: Christian Borntraeger 
Cc: Minchan Kim 
Cc: Jiang Liu 
Cc: Nitin Gupta 
Cc: Jerome Marchand 
Cc: Joe Perches 
Cc: Peng Tao 
Cc: Andy Adamson 
Cc: fanchaoting 
Cc: Jie Liu 
Cc: Sunil Mushran 
Cc: "Martin K. Petersen" 
Cc: Namjae Jeon 
Cc: Pankaj Kumar 
Cc: Dan Magenheimer 
Cc: Mel Gorman 6