linux-stable.git/drivers/md/persistent-data, branch linux-3.4.y

dm btree: fix bufio buffer leaks in dm_btree_del() error path

2016-10-26T15:15:36+00:00

commit ed8b45a3679eb49069b094c0711b30833f27c734 upstream.

If dm_btree_del()'s call to push_frame() fails, e.g. due to
btree_node_validator finding invalid metadata, the dm_btree_del() error
path must unlock all frames (which have active dm-bufio buffers) that
were pushed onto the del_stack.

Otherwise, dm_bufio_client_destroy() will BUG_ON() because dm-bufio
buffers have leaked, e.g.:
  device-mapper: bufio: leaked buffer 3, hold count 1, list 0

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Zefan Li

dm btree: fix leak of bufio-backed block in btree_split_sibling error path

2016-10-26T15:15:35+00:00

commit 30ce6e1cc5a0f781d60227e9096c86e188d2c2bd upstream.

The block allocated at the start of btree_split_sibling() is never
released if later insert_at() fails.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Zefan Li

dm btree: fix leak of bufio-backed block in btree_split_beneath error path

2016-04-27T10:55:29+00:00

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream.

btree_split_beneath()'s error path had an outstanding FIXME that speaks
directly to the potential for _not_ cleaning up a previously allocated
bufio-backed block.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Signed-off-by: Zefan Li

dm btree remove: fix a bug when rebalancing nodes after removal

2016-03-21T01:17:58+00:00

commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream.

Commit 4c7e309340ff ("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 
Signed-off-by: Mike Snitzer 
Signed-off-by: Zefan Li

dm btree: add ref counting ops for the leaves of top level btrees

2016-03-21T01:17:52+00:00

commit b0dc3c8bc157c60b1d470163882be8c13e1950af upstream.

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 
Signed-off-by: Mike Snitzer 
[lizf: Backported to 3.4:
 - drop const
 - drop changes to remove_one()]
Signed-off-by: Zefan Li

dm btree: silence lockdep lock inversion in dm_btree_del()

2016-03-21T01:17:42+00:00

commit 1c7518794a3647eb345d59ee52844e8a40405198 upstream.

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 
Signed-off-by: Mike Snitzer 
Signed-off-by: Zefan Li

dm btree remove: fix bug in redistribute3

2016-03-21T01:17:41+00:00

commit 4c7e309340ff85072e96f529582d159002c36734 upstream.

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 
Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Zefan Li

dm thin: fix discard corruption

2014-06-07T23:02:05+00:00

commit f046f89a99ccfd9408b94c653374ff3065c7edb3 upstream.

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.

Signed-off-by: Joe Thornber 
Signed-off-by: Alasdair G Kergon 
[bwh: Backported to 3.2: bump target version numbers from 1.0.1 to 1.0.2]
Signed-off-by: Ben Hutchings 
[xr: Backported to 3.4: bump target version numbers to 1.1.1]
Signed-off-by: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman

dm space map common: make sure new space is used during extend

2014-02-13T19:51:14+00:00

commit 12c91a5c2d2a8e8cc40a9552313e1e7b0a2d9ee3 upstream.

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 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm persistent data: rename node to btree_node

2013-01-17T16:50:51+00:00

commit 550929faf89e2e2cdb3e9945ea87d383989274cf upstream.

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 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman