Commit Graph

72 Commits

Author SHA1 Message Date
Joe Thornber aa0cd28d05 dm btree remove: fix bug in remove_one()
remove_one() was not incrementing the key for the beginning of the
range, so not all entries were being removed.  This resulted in
discards that were not unmapping all blocks.

Fixes: 4ec331c3ea ("dm btree: add dm_btree_remove_leaves()")
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-08-07 11:56:43 -04:00
Joe Thornber 1c7518794a dm btree: silence lockdep lock inversion in dm_btree_del()
Allocate memory using GFP_NOIO when deleting a btree.  dm_btree_del()
can be called via an ioctl and we don't want to recurse into the FS or
block layer.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2015-07-06 10:45:02 -04:00
Dennis Yang 4c7e309340 dm btree remove: fix bug in redistribute3
redistribute3() shares entries out across 3 nodes.  Some entries were
being moved the wrong way, breaking the ordering.  This manifested as a
BUG() in dm-btree-remove.c:shift() when entries were removed from the
btree.

For additional context see:
https://www.redhat.com/archives/dm-devel/2015-May/msg00113.html

Signed-off-by: Dennis Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2015-07-05 17:43:58 -04:00
Joe Thornber 6096d91af0 dm space map metadata: fix occasional leak of a metadata block on resize
The metadata space map has a simplified 'bootstrap' mode that is
operational when extending the space maps.  Whilst in this mode it's
possible for some refcount decrement operations to become queued (eg, as
a result of shadowing one of the bitmap indexes).  These decrements were
not being applied when switching out of bootstrap mode.

The effect of this bug was the leaking of a 4k metadata block.  This is
detected by the latest version of thin_check as a non fatal error.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2015-06-17 10:09:23 -04:00
Joe Thornber 4ec331c3ea dm btree: add dm_btree_remove_leaves()
Removes a range of leaf values from the tree.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-11 17:13:03 -04:00
Mike Snitzer 49f154c732 dm thin metadata: remove in-core 'read_only' flag
Leverage the block manager's read_only flag instead of duplicating it;
access with new dm_bm_is_read_only() method.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 14:18:59 -04:00
Linus Torvalds a911dcdba1 - Significant dm-crypt CPU scalability performance improvements thanks
to changes that enable effective use of an unbound workqueue across
   all available CPUs.  A large battery of tests were performed to
   validate these changes, summary of results is available here:
   https://www.redhat.com/archives/dm-devel/2015-February/msg00106.html
 
 - A few additional stable fixes (to DM core, dm-snapshot and dm-mirror)
   and a small fix to the dm-space-map-disk.
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Merge tag 'dm-3.20-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull more device mapper changes from Mike Snitzer:

- Significant dm-crypt CPU scalability performance improvements thanks
  to changes that enable effective use of an unbound workqueue across
  all available CPUs.  A large battery of tests were performed to
  validate these changes, summary of results is available here:
  https://www.redhat.com/archives/dm-devel/2015-February/msg00106.html

- A few additional stable fixes (to DM core, dm-snapshot and dm-mirror)
  and a small fix to the dm-space-map-disk.

* tag 'dm-3.20-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm snapshot: fix a possible invalid memory access on unload
  dm: fix a race condition in dm_get_md
  dm crypt: sort writes
  dm crypt: add 'submit_from_crypt_cpus' option
  dm crypt: offload writes to thread
  dm crypt: remove unused io_pool and _crypt_io_pool
  dm crypt: avoid deadlock in mempools
  dm crypt: don't allocate pages for a partial request
  dm crypt: use unbound workqueue for request processing
  dm io: reject unsupported DISCARD requests with EOPNOTSUPP
  dm mirror: do not degrade the mirror on discard error
  dm space map disk: fix sm_disk_count_is_more_than_one()
2015-02-21 13:28:45 -08:00
Mike Snitzer 145b9006a0 dm space map disk: fix sm_disk_count_is_more_than_one()
dm_tm_shadow_block() is the only caller of
dm_sm_count_is_more_than_one() which only ever operates on a metadata
space-map.  So in practice, sm_disk_count_is_more_than_one() isn't
actually used (which explains why this bug never amounted to anything).

But fix sm_disk_count_is_more_than_one() to properly set *result and
return 0.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-13 19:32:58 -05:00
Christoph Jaeger 6341e62b21 kconfig: use bool instead of boolean for type definition attributes
Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-07 13:08:04 +01:00
Joe Thornber 02717d9855 dm space map metadata: fix sm_bootstrap_get_count()
Must set 'result' accordingly rather than return it.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-02 10:25:06 -05:00
Dan Carpenter c1c6156fe4 dm space map metadata: fix sm_bootstrap_get_nr_blocks()
This function isn't right and it causes a static checker warning:

	drivers/md/dm-thin.c:3016 maybe_resize_data_dev()
	error: potentially using uninitialized 'sb_data_size'.

It should set "*count" and return zero on success the same as the
sm_metadata_get_nr_blocks() function does earlier.

Fixes: 3241b1d3e0 ('dm: add persistent data library')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-01 11:31:58 -05:00
Joe Thornber 8001e87d0e dm array: if resizing the array is a noop set the new root to the old one
This could've been quite bad (to return success but not update the new
root to point at the old) but in practice the only known consumer of the
dm array code is the DM cache target.  And the DM cache target passes in
the same old root to array_resize() anyway.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-01 11:30:07 -05:00
Joe Thornber 4646015d7e dm transaction manager: add support for prefetching blocks of metadata
Introduce the dm_tm_issue_prefetches interface.  If you're using a
non-blocking clone the tm will build up a list of requested blocks that
weren't in core.  dm_tm_issue_prefetches will request those blocks to be
prefetched.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-11-10 15:25:26 -05:00
Joe Thornber 9b460d3699 dm btree: fix a recursion depth bug in btree walking code
The walk code was using a 'ro_spine' to hold it's locked btree nodes.
But this data structure is designed for the rolling lock scheme, and
as such automatically unlocks blocks that are two steps up the call
chain.  This is not suitable for the simple recursive walk algorithm,
which retraces its steps.

This code is only used by the persistent array code, which in turn is
only used by dm-cache.  In order to trigger it you need to have a
mapping tree that is more than 2 levels deep; which equates to 8-16
million cache blocks.  For instance a 4T ssd with a very small block
size of 32k only just triggers this bug.

The fix just places the locked blocks on the stack, and stops using
the ro_spine altogether.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-11-10 15:23:58 -05:00
Joe Thornber a9d45396f5 dm transaction manager: fix corruption due to non-atomic transaction commit
The persistent-data library used by dm-thin, dm-cache, etc is
transactional.  If anything goes wrong, such as an io error when writing
new metadata or a power failure, then we roll back to the last
transaction.

Atomicity when committing a transaction is achieved by:

a) Never overwriting data from the previous transaction.
b) Writing the superblock last, after all other metadata has hit the
   disk.

This commit and the following commit ("dm: take care to copy the space
map roots before locking the superblock") fix a bug associated with (b).
When committing it was possible for the superblock to still be written
in spite of an io error occurring during the preceeding metadata flush.
With these commits we're careful not to take the write lock out on the
superblock until after the metadata flush has completed.

Change the transaction manager's semantics for dm_tm_commit() to assume
all data has been flushed _before_ the single superblock that is passed
in.

As a prerequisite, split the block manager's block unlocking and
flushing by simplifying dm_bm_flush_and_unlock() to dm_bm_flush().  Now
the unlocking must be done separately.

This issue was discovered by forcing io errors at the crucial time
using dm-flakey.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-03-27 16:56:23 -04:00
Joe Thornber 428e469864 dm bitset: only flush the current word if it has been dirtied
This change offers a big performance boost for dm-era.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:23 -04:00
Joe Thornber cebc2de44d dm space map metadata: fix refcount decrement below 0 which caused corruption
This has been a relatively long-standing issue that wasn't nailed down
until Teng-Feng Yang's meticulous bug report to dm-devel on 3/7/2014,
see: http://www.redhat.com/archives/dm-devel/2014-March/msg00021.html

From that report:
  "When decreasing the reference count of a metadata block with its
  reference count equals 3, we will call dm_btree_remove() to remove
  this enrty from the B+tree which keeps the reference count info in
  metadata device.

  The B+tree will try to rebalance the entry of the child nodes in each
  node it traversed, and the rebalance process contains the following
  steps.

  (1) Finding the corresponding children in current node (shadow_current(s))
  (2) Shadow the children block (issue BOP_INC)
  (3) redistribute keys among children, and free children if necessary (issue BOP_DEC)

  Since the update of a metadata block's reference count could be
  recursive, we will stash these reference count update operations in
  smm->uncommitted and then process them in a FILO fashion.

  The problem is that step(3) could free the children which is created
  in step(2), so the BOP_DEC issued in step(3) will be carried out
  before the BOP_INC issued in step(2) since these BOPs will be
  processed in FILO fashion. Once the BOP_DEC from step(3) tries to
  decrease the reference count of newly shadow block, it will report
  failure for its reference equals 0 before decreasing. It looks like we
  can solve this issue by processing these BOPs in a FIFO fashion
  instead of FILO."

Commit 5b564d80 ("dm space map: disallow decrementing a reference count
below zero") changed the code to report an error for this temporary
refcount decrement below zero.  So what was previously a harmless
invalid refcount became a hard failure due to the new error path:

 device-mapper: space map common: unable to decrement a reference count below 0
 device-mapper: thin: 253:6: dm_thin_insert_block() failed: error = -22
 device-mapper: thin: 253:6: switching pool to read-only mode

This bug is in dm persistent-data code that is common to the DM thin and
cache targets.  So any users of those targets should apply this fix.

Fix this by applying recursive space map operations in FIFO order rather
than FILO.

Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=68801

Reported-by: Apollon Oikonomopoulos <apoikos@debian.org>
Reported-by: edwillam1007@gmail.com
Reported-by: Teng-Feng Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
2014-03-07 12:02:47 -05:00
Mike Snitzer c64d240df3 dm: fix Kconfig indentation
Since DM_DEBUG_BLOCK_STACK_TRACING is a DM_PERSISTENT_DATA config option
move it from drivers/md/Kconfig to drivers/md/persistent-data/Kconfig.

Doing so fixes indentation for other DM config options.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-03 17:31:07 -05:00
Mike Snitzer 7d48935eff dm thin: allow metadata space larger than supported to go unused
It was always intended that a user could provide a thin metadata device
that is larger than the max supported by the on-disk format.  The extra
space would just go unused.

Unfortunately that never worked.  If the user attempted to use a larger
metadata device on creation they would get an error like the following:

 device-mapper: space map common: space map too large
 device-mapper: transaction manager: couldn't create metadata space map
 device-mapper: thin metadata: tm_create_with_sm failed
 device-mapper: table: 252:17: thin-pool: Error creating metadata object
 device-mapper: ioctl: error adding target to table

Fix this by allowing the initial metadata space map creation to cap its
size at the max number of blocks supported (DM_SM_METADATA_MAX_BLOCKS).
get_metadata_dev_size() must also impose DM_SM_METADATA_MAX_BLOCKS (via
THIN_METADATA_MAX_SECTORS), otherwise extending metadata would cap at
THIN_METADATA_MAX_SECTORS_WARNING (which is larger than supported).

Also, the calculation for THIN_METADATA_MAX_SECTORS didn't account for
the sizeof the disk_bitmap_header.  So the supported maximum metadata
size is a bit smaller (reduced from 33423360 to 33292800 sectors).

Lastly, remove the "excess space will not be used" warning message from
get_metadata_dev_size(); it resulted in printing the warning multiple
times.  Factor out warn_if_metadata_device_too_big(), call it from
pool_ctr() and maybe_resize_metadata_dev().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-02-27 11:49:08 -05:00
Joe Thornber fca028438f dm space map metadata: fix bug in resizing of thin metadata
This bug was introduced in commit 7e664b3dec ("dm space map metadata:
fix extending the space map").

When extending a dm-thin metadata volume we:

- Switch the space map into a simple bootstrap mode, which allocates
  all space linearly from the newly added space.
- Add new bitmap entries for the new space
- Increment the reference counts for those newly allocated bitmap
  entries
- Commit changes to disk
- Switch back out of bootstrap mode.

But, the disk commit may allocate space itself, if so this fact will be
lost when switching out of bootstrap mode.

The bug exhibited itself as an error when the bitmap_root, with an
erroneous ref count of 0, was subsequently decremented as part of a
later disk commit.  This would cause the disk commit to fail, and thinp
to enter read_only mode.  The metadata was not damaged (thin_check
passed).

The fix is to put the increments + commit into a loop, running until
the commit has not allocated extra space.  In practise this loop only
runs twice.

With this fix the following device mapper testsuite test passes:
 dmtest run --suite thin-provisioning -n thin_remove_works_after_resize

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # depends on commit 7e664b3dec
2014-01-21 12:15:01 -05:00
Joe Thornber f164e6900f dm btree: add dm_btree_find_lowest_key
dm_btree_find_lowest_key is the reciprocal of dm_btree_find_highest_key.
Factor out common code for dm_btree_find_{highest,lowest}_key.

dm_btree_find_lowest_key is needed for an upcoming DM target, as such it
is best to get this interface in place.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-09 16:29:17 -05:00
Joe Thornber 7e664b3dec dm space map metadata: fix extending the space map
When extending a metadata space map we should do the first commit whilst
still in bootstrap mode -- a mode where all blocks get allocated in the
new area.

That way the commit overhead is allocated from the newly added space.
Otherwise we risk running out of space.

With this fix, and the previous commit "dm space map common: make sure
new space is used during extend", the following device mapper testsuite
test passes:
 dmtest run --suite thin-provisioning -n /resize_metadata_no_io/

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-01-07 21:05:18 -05:00
Joe Thornber 12c91a5c2d dm space map common: make sure new space is used during extend
When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.

Otherwise extend can fail, e.g.: sm_metadata_extend call sequence
that fails:
 -> sm_ll_extend
    -> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block
    => returns -ENOSPC because smm->begin == smm->ll.nr_blocks

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-01-07 21:05:17 -05:00
Mike Snitzer 10343180f5 dm persistent data: cleanup dm-thin specific references in text
DM's persistent-data library is now used my multiple targets so
exclusive references to "pool" or "thin provisioning" need to be
cleaned up.  Adjust Kconfig's DM_DEBUG_BLOCK_STACK_TRACING text
and remove "pool" from a block manager error message.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-01-07 10:11:54 -05:00
Mike Snitzer c46985e211 dm space map metadata: limit errors in sm_metadata_new_block
The "unable to allocate new metadata block" error can be a particularly
verbose error if there is a systemic issue with the metadata device.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-01-07 10:11:46 -05:00
Joe Thornber ed9571f0cf dm array: fix a reference counting bug in shadow_ablock
An old array block could have its reference count decremented below
zero when it is being replaced in the btree by a new array block.

The fix is to increment the old ablock's reference count just before
inserting a new ablock into the btree.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-12-13 14:22:10 -05:00
Joe Thornber 5b564d80f8 dm space map: disallow decrementing a reference count below zero
The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063 ("dm space map: optimise
sm_ll_dec and sm_ll_inc").  To fix this regression we return an error
code from the mutator function pointer passed to sm_ll_mutate() and have
dec_ref_count() return -EINVAL if the old ref_count is 0.

Add a DMERR to reflect the potential seriousness of this error.

Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path.

With this fix the following dmts regression test now passes:
 dmtest run --suite cache -n /metadata_use_kernel/

The next patch fixes the higher-level dm-array code that exposed this
regression.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.12+
2013-12-13 14:22:09 -05:00
Joe Thornber 9b7aaa64f9 dm thin: allow pool in read-only mode to transition to read-write mode
A thin-pool may be in read-only mode because the pool's data or metadata
space was exhausted.  To allow for recovery, by adding more space to the
pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE
mode.  Otherwise, running out of space will render the pool permanently
read-only.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2013-12-10 16:35:13 -05:00
Mike Snitzer f62b6b8f49 dm space map metadata: return on failure in sm_metadata_new_block
Commit 2fc48021f4 ("dm persistent
metadata: add space map threshold callback") introduced a regression
to the metadata block allocation path that resulted in errors being
ignored.  This regression was uncovered by running the following
device-mapper-test-suite test:
dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/

The ignored error codes in sm_metadata_new_block() could crash the
kernel through use of either the dm-thin or dm-cache targets, e.g.:

device-mapper: thin: 253:4: reached low water mark for metadata device: sending event.
device-mapper: space map metadata: unable to allocate new metadata block
general protection fault: 0000 [#1] SMP
...
Workqueue: dm-thin do_worker [dm_thin_pool]
task: ffff880035ce2ab0 ti: ffff88021a054000 task.ti: ffff88021a054000
RIP: 0010:[<ffffffffa0331385>]  [<ffffffffa0331385>] metadata_ll_load_ie+0x15/0x30 [dm_persistent_data]
RSP: 0018:ffff88021a055a68  EFLAGS: 00010202
RAX: 003fc8243d212ba0 RBX: ffff88021a780070 RCX: ffff88021a055a78
RDX: ffff88021a055a78 RSI: 0040402222a92a80 RDI: ffff88021a780070
RBP: ffff88021a055a68 R08: ffff88021a055ba4 R09: 0000000000000010
R10: 0000000000000000 R11: 00000002a02e1000 R12: ffff88021a055ad4
R13: 0000000000000598 R14: ffffffffa0338470 R15: ffff88021a055ba4
FS:  0000000000000000(0000) GS:ffff88033fca0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f467c0291b8 CR3: 0000000001a0b000 CR4: 00000000000007e0
Stack:
 ffff88021a055ab8 ffffffffa0332020 ffff88021a055b30 0000000000000001
 ffff88021a055b30 0000000000000000 ffff88021a055b18 0000000000000000
 ffff88021a055ba4 ffff88021a055b98 ffff88021a055ae8 ffffffffa033304c
Call Trace:
 [<ffffffffa0332020>] sm_ll_lookup_bitmap+0x40/0xa0 [dm_persistent_data]
 [<ffffffffa033304c>] sm_metadata_count_is_more_than_one+0x8c/0xc0 [dm_persistent_data]
 [<ffffffffa0333825>] dm_tm_shadow_block+0x65/0x110 [dm_persistent_data]
 [<ffffffffa0331b00>] sm_ll_mutate+0x80/0x300 [dm_persistent_data]
 [<ffffffffa0330e60>] ? set_ref_count+0x10/0x10 [dm_persistent_data]
 [<ffffffffa0331dba>] sm_ll_inc+0x1a/0x20 [dm_persistent_data]
 [<ffffffffa0332270>] sm_disk_new_block+0x60/0x80 [dm_persistent_data]
 [<ffffffff81520036>] ? down_write+0x16/0x40
 [<ffffffffa001e5c4>] dm_pool_alloc_data_block+0x54/0x80 [dm_thin_pool]
 [<ffffffffa001b23c>] alloc_data_block+0x9c/0x130 [dm_thin_pool]
 [<ffffffffa001c27e>] provision_block+0x4e/0x180 [dm_thin_pool]
 [<ffffffffa001fe9a>] ? dm_thin_find_block+0x6a/0x110 [dm_thin_pool]
 [<ffffffffa001c57a>] process_bio+0x1ca/0x1f0 [dm_thin_pool]
 [<ffffffff8111e2ed>] ? mempool_free+0x8d/0xa0
 [<ffffffffa001d755>] process_deferred_bios+0xc5/0x230 [dm_thin_pool]
 [<ffffffffa001d911>] do_worker+0x51/0x60 [dm_thin_pool]
 [<ffffffff81067872>] process_one_work+0x182/0x3b0
 [<ffffffff81068c90>] worker_thread+0x120/0x3a0
 [<ffffffff81068b70>] ? manage_workers+0x160/0x160
 [<ffffffff8106eb2e>] kthread+0xce/0xe0
 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70
 [<ffffffff8152af6c>] ret_from_fork+0x7c/0xb0
 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70
 [<ffffffff8152af6c>] ret_from_fork+0x7c/0xb0
 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # v3.10+
2013-12-10 16:34:28 -05:00
Joe Thornber 40c57f475f dm space map disk: optimise sm_disk_dec_block
Don't waste time spotting blocks that have been allocated and then freed
in the same transaction.

The extra lookup is expensive, and I don't think it really gives us much.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:24 -05:00
Joe Thornber 9c1d4de560 dm array: fix bug in growing array
Entries would be lost if the old tail block was partially filled.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-05 11:20:50 -05:00
Joe Thornber f722063ee0 dm space map: optimise sm_ll_dec and sm_ll_inc
Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function.  This avoids traversing the data
structures twice and hence improves performance.

Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber 04f17c802f dm btree: prefetch child nodes when walking tree for a dm_btree_del
dm-btree now takes advantage of dm-bufio's ability to prefetch data via
dm_bm_prefetch().  Prior to this change many btree node visits were
causing a synchronous read.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber cd5acf0b44 dm btree: use pop_frame in dm_btree_del to cleanup code
Remove a visited leaf straight away from the stack, rather than
marking all it's children as visited and letting it get removed on the
next iteration.  May also offer a micro optimisation in dm_btree_del.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber 2fc48021f4 dm persistent metadata: add space map threshold callback
Add a threshold callback to dm persistent data space maps.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber 7c3d3f2a87 dm persistent data: add threshold callback to space map
Add a threshold callback function to the persistent data space map
interface for a subsequent patch to use.

dm-thin and dm-cache are interested in knowing when they're getting
low on metadata or data blocks.  This patch introduces a new method
for registering a callback against a threshold.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber 1921c56d95 dm persistent data: support space map resizing
Support extending a dm persistent data metadata space map.

The extend itself is implemented by switching back to the boostrap
allocator and pointing to the new space.  The extra bitmap indexes are
then allocated from the new space, and finally we switch back to the
proper space map ops and tweak the reference counts.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber 88a488f624 dm persistent data: fix error message typos
Fix some typos in dm-space-map-metadata.c error messages.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:17 +01:00
Joe Thornber f046f89a99 dm thin: fix discard corruption
Fix a bug in dm_btree_remove that could leave leaf values with incorrect
reference counts.  The effect of this was that removal of a shared block
could result in the space maps thinking the block was no longer used.
More concretely, if you have a thin device and a snapshot of it, sending
a discard to a shared region of the thin could corrupt the snapshot.

Thinp uses a 2-level nested btree to store it's mappings.  This first
level is indexed by thin device, and the second level by logical
block.

Often when we're removing an entry in this mapping tree we need to
rebalance nodes, which can involve shadowing them, possibly creating a
copy if the block is shared.  If we do create a copy then children of
that node need to have their reference counts incremented.  In this
way reference counts percolate down the tree as shared trees diverge.

The rebalance functions were incrementing the children at the
appropriate time, but they were always assuming the children were
internal nodes.  This meant the leaf values (in our case packed
block/flags entries) were not being incremented.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:24 +00:00
Joe Thornber c6b4fcbad0 dm: add cache target
Add a target that allows a fast device such as an SSD to be used as a
cache for a slower device such as a disk.

A plug-in architecture was chosen so that the decisions about which data
to migrate and when are delegated to interchangeable tunable policy
modules.  The first general purpose module we have developed, called
"mq" (multiqueue), follows in the next patch.  Other modules are
under development.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber 7a87edfee7 dm persistent data: add bitset
Add a persistent bitset as a wrapper around dm-array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber 6513c29f44 dm persistent data: add transactional array
Add a transactional array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber 4e7f1f9089 dm persistent data: add btree_walk
Add dm_btree_walk to iterate through the contents of a btree.
This will be used by the dm cache target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Mike Snitzer 018cede93c dm persistent data: set some btree fn parms const
Mark some constant parameters constant in some dm-btree functions.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Kees Cook 88ae4c5294 dm persistent data: remove CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:46 +00:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Andrew Morton df8557982f drivers/md/persistent-data/dm-transaction-manager.c: rename HASH_SIZE
Fix the warning:

  drivers/md/persistent-data/dm-transaction-manager.c:28:1: warning: "HASH_SIZE" redefined
  In file included from include/linux/elevator.h:5,
                   from include/linux/blkdev.h:216,
                   from drivers/md/persistent-data/dm-block-manager.h:11,
                   from drivers/md/persistent-data/dm-transaction-manager.h:10,
                   from drivers/md/persistent-data/dm-transaction-manager.c:6:
  include/linux/hashtable.h:22:1: warning: this is the location of the previous definition

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:08 -08:00
Linus Torvalds b49249d103 Miscellaneous device-mapper fixes, cleanups and performance improvements.
Of particular note:
 - Disable broken WRITE SAME support in all targets except linear and striped.
   Use it when kcopyd is zeroing blocks.
 - Remove several mempools from targets by moving the data into the bio's new
   front_pad area(which dm calls 'per_bio_data').
 - Fix a race in thin provisioning if discards are misused.
 - Prevent userspace from interfering with the ioctl parameters and
   use kmalloc for the data buffer if it's small instead of vmalloc.
 - Throttle some annoying error messages when I/O fails.
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Merge tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull dm update from Alasdair G Kergon:
 "Miscellaneous device-mapper fixes, cleanups and performance
  improvements.

  Of particular note:
   - Disable broken WRITE SAME support in all targets except linear and
     striped.  Use it when kcopyd is zeroing blocks.
   - Remove several mempools from targets by moving the data into the
     bio's new front_pad area(which dm calls 'per_bio_data').
   - Fix a race in thin provisioning if discards are misused.
   - Prevent userspace from interfering with the ioctl parameters and
     use kmalloc for the data buffer if it's small instead of vmalloc.
   - Throttle some annoying error messages when I/O fails."

* tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (36 commits)
  dm stripe: add WRITE SAME support
  dm: remove map_info
  dm snapshot: do not use map_context
  dm thin: dont use map_context
  dm raid1: dont use map_context
  dm flakey: dont use map_context
  dm raid1: rename read_record to bio_record
  dm: move target request nr to dm_target_io
  dm snapshot: use per_bio_data
  dm verity: use per_bio_data
  dm raid1: use per_bio_data
  dm: introduce per_bio_data
  dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
  dm linear: add WRITE SAME support
  dm: add WRITE SAME support
  dm: prepare to support WRITE SAME
  dm ioctl: use kmalloc if possible
  dm ioctl: remove PF_MEMALLOC
  dm persistent data: improve improve space map block alloc failure message
  dm thin: use DMERR_LIMIT for errors
  ...
2012-12-21 17:08:06 -08:00
Joe Thornber 7960123f2d dm persistent data: improve improve space map block alloc failure message
Improve space map error message when unable to allocate a new
metadata block.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:36 +00:00
Mike Snitzer 89ddeb8cb1 dm persistent data: use DMERR_LIMIT for errors
Nearly all of persistent-data is in the IO path so throttle error
messages with DMERR_LIMIT to limit the amount logged when
something has gone wrong.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:34 +00:00