users (e.g. kvm guests) that issued ioctls when a multipath device had
no available paths.
- Include Christoph's refactoring of DM's ioctl handling and add support
for passing through persistent reservations with DM multipath.
- All other changes are very simple cleanups.
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Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
"Smaller set of DM changes for this merge. I've based these changes on
Jens' for-4.4/reservations branch because the associated DM changes
required it.
- Revert a dm-multipath change that caused a regression for
unprivledged users (e.g. kvm guests) that issued ioctls when a
multipath device had no available paths.
- Include Christoph's refactoring of DM's ioctl handling and add
support for passing through persistent reservations with DM
multipath.
- All other changes are very simple cleanups"
* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm switch: simplify conditional in alloc_region_table()
dm delay: document that offsets are specified in sectors
dm delay: capitalize the start of an delay_ctr() error message
dm delay: Use DM_MAPIO macros instead of open-coded equivalents
dm linear: remove redundant target name from error messages
dm persistent data: eliminate unnecessary return values
dm: eliminate unused "bioset" process for each bio-based DM device
dm: convert ffs to __ffs
dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
dm: add support for passing through persistent reservations
dm: refactor ioctl handling
Revert "dm mpath: fix stalls when handling invalid ioctls"
dm: initialize non-blk-mq queue data before queue is used
dm_bm_unlock and dm_tm_unlock return an integer value but the returned
value is always 0. The calling code sometimes checks the return value
and sometimes doesn't.
Eliminate these unnecessary return values and also the checks for them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 4c7e309340 ("dm btree remove: fix bug in redistribute3") wasn't
a complete fix for redistribute3().
The redistribute3 function takes 3 btree nodes and shares out the entries
evenly between them. If the three nodes in total contained
(MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting
rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in
the center.
Fix this issue by being more careful about calculating the target number
of entries for the left and right nodes.
Unit tested in userspace using this program:
https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
rebalance_children() calls get_nr_entries() and assigns the result to an
unused local 'child_entries' variable. Remove get_nr_entries() and
cleanup rebalance_children() accordingly.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When using nested btrees, the top leaves of the top levels contain
block addresses for the root of the next tree down. If we shadow a
shared leaf node the leaf values (sub tree roots) should be incremented
accordingly.
This is only an issue if there is metadata sharing in the top levels.
Which only occurs if metadata snapshots are being used (as is possible
with dm-thinp). And could result in a block from the thinp metadata
snap being reused early, thus corrupting the thinp metadata snap.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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>
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
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>
This patch fixes a compilation failure on sparc32 by renaming struct node.
struct node is already defined in include/linux/node.h. On sparc32, it
happens to be included through other dependencies and persistent-data
doesn't compile because of conflicting declarations.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Now that the value_size is held within every node of the btrees we can
remove this argument from value_ptr().
For the last few months a BUG_ON has been checking this argument is
the same as that held in the node. No issues were reported. So this
is a safe change.
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>
When we remove an entry from a node we sometimes rebalance with it's
two neighbours. This wasn't being done correctly; in some cases
entries have to move all the way from the right neighbour to the left
neighbour, or vice versa. This patch pretty much re-writes the
balancing code to fix it.
This code is barely used currently; only when you delete a thin
device, and then only if you have hundreds of them in the same pool.
Once we have discard support, which removes mappings, this will be used
much more heavily.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
For the files which are not themselves modular, we can change
them to include only the smaller export.h since all they are
doing is looking for EXPORT_SYMBOL.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The persistent-data library offers a re-usable framework for the storage
and management of on-disk metadata in device-mapper targets.
It's used by the thin-provisioning target in the next patch and in an
upcoming hierarchical storage target.
For further information, please read
Documentation/device-mapper/persistent-data.txt
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
