<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/drivers/md/persistent-data, branch v4.4.272</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.4.272</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.4.272'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2021-05-22T08:38:20Z</updated>
<entry>
<title>dm space map common: fix division bug in sm_ll_find_free_block()</title>
<updated>2021-05-22T08:38:20Z</updated>
<author>
<name>Joe Thornber</name>
<email>ejt@redhat.com</email>
</author>
<published>2021-04-13T08:11:53Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e9ebaaa29eec65d80b19fc6ed4d2c408085217e2'/>
<id>urn:sha1:e9ebaaa29eec65d80b19fc6ed4d2c408085217e2</id>
<content type='text'>
commit 5208692e80a1f3c8ce2063a22b675dd5589d1d80 upstream.

This division bug meant the search for free metadata space could skip
the final allocation bitmap's worth of entries. Fix affects DM thinp,
cache and era targets.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Tested-by: Ming-Hung Tsai &lt;mtsai@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>dm persistent data: packed struct should have an aligned() attribute too</title>
<updated>2021-05-22T08:38:20Z</updated>
<author>
<name>Joe Thornber</name>
<email>ejt@redhat.com</email>
</author>
<published>2021-03-29T15:34:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e9a972de2d22d030318ad468123f06c2d1fbb1c6'/>
<id>urn:sha1:e9a972de2d22d030318ad468123f06c2d1fbb1c6</id>
<content type='text'>
commit a88b2358f1da2c9f9fcc432f2e0a79617fea397c upstream.

Otherwise most non-x86 architectures (e.g. riscv, arm) will resort to
byte-by-byte access.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>dm space map common: fix to ensure new block isn't already in use</title>
<updated>2020-02-14T21:29:56Z</updated>
<author>
<name>Joe Thornber</name>
<email>ejt@redhat.com</email>
</author>
<published>2020-01-07T11:58:42Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4c3816edfbad2be6c8df08f2925c3487197aa850'/>
<id>urn:sha1:4c3816edfbad2be6c8df08f2925c3487197aa850</id>
<content type='text'>
commit 4feaef830de7ffdd8352e1fe14ad3bf13c9688f8 upstream.

The space-maps track the reference counts for disk blocks allocated by
both the thin-provisioning and cache targets.  There are variants for
tracking metadata blocks and data blocks.

Transactionality is implemented by never touching blocks from the
previous transaction, so we can rollback in the event of a crash.

When allocating a new block we need to ensure the block is free (has
reference count of 0) in both the current and previous transaction.
Prior to this fix we were doing this by searching for a free block in
the previous transaction, and relying on a 'begin' counter to track
where the last allocation in the current transaction was.  This
'begin' field was not being updated in all code paths (eg, increment
of a data block reference count due to breaking sharing of a neighbour
block in the same btree leaf).

This fix keeps the 'begin' field, but now it's just a hint to speed up
the search.  Instead the current transaction is searched for a free
block, and then the old transaction is double checked to ensure it's
free.  Much simpler.

This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when
DM thin-provisioning's snapshots are heavily used.

Reported-by: Eric Wheeler &lt;dm-devel@lists.ewheeler.net&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm btree: increase rebalance threshold in __rebalance2()</title>
<updated>2019-12-21T09:35:46Z</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2019-12-03T11:42:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=14883c635a650781dbf7d9b067362be8b1a8fcef'/>
<id>urn:sha1:14883c635a650781dbf7d9b067362be8b1a8fcef</id>
<content type='text'>
commit 474e559567fa631dea8fb8407ab1b6090c903755 upstream.

We got the following warnings from thin_check during thin-pool setup:

  $ thin_check /dev/vdb
  examining superblock
  examining devices tree
    missing devices: [1, 84]
      too few entries in btree_node: 41, expected at least 42 (block 138, max_entries = 126)
  examining mapping tree

The phenomenon is the number of entries in one node of details_info tree is
less than (max_entries / 3). And it can be easily reproduced by the following
procedures:

  $ new a thin pool
  $ presume the max entries of details_info tree is 126
  $ new 127 thin devices (e.g. 1~127) to make the root node being full
    and then split
  $ remove the first 43 (e.g. 1~43) thin devices to make the children
    reblance repeatedly
  $ stop the thin pool
  $ thin_check

The root cause is that the B-tree removal procedure in __rebalance2()
doesn't guarantee the invariance: the minimal number of entries in
non-root node should be &gt;= (max_entries / 3).

Simply fix the problem by increasing the rebalance threshold to
make sure the number of entries in each child will be greater
than or equal to (max_entries / 3 + 1), so no matter which
child is used for removal, the number will still be valid.

Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Acked-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm space map metadata: fix missing store of apply_bops() return value</title>
<updated>2019-09-06T08:18:10Z</updated>
<author>
<name>ZhangXiaoxu</name>
<email>zhangxiaoxu5@huawei.com</email>
</author>
<published>2019-08-19T03:31:21Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=77529c247cc212aea4600e8c552a063abf5f91e4'/>
<id>urn:sha1:77529c247cc212aea4600e8c552a063abf5f91e4</id>
<content type='text'>
commit ae148243d3f0816b37477106c05a2ec7d5f32614 upstream.

In commit 6096d91af0b6 ("dm space map metadata: fix occasional leak
of a metadata block on resize"), we refactor the commit logic to a new
function 'apply_bops'.  But when that logic was replaced in out() the
return value was not stored.  This may lead out() returning a wrong
value to the caller.

Fixes: 6096d91af0b6 ("dm space map metadata: fix occasional leak of a metadata block on resize")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu &lt;zhangxiaoxu5@huawei.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm btree: fix order of block initialization in btree_split_beneath</title>
<updated>2019-09-06T08:18:10Z</updated>
<author>
<name>ZhangXiaoxu</name>
<email>zhangxiaoxu5@huawei.com</email>
</author>
<published>2019-08-17T05:32:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=063c4d18688b9e34c74327247a1292fe13745438'/>
<id>urn:sha1:063c4d18688b9e34c74327247a1292fe13745438</id>
<content type='text'>
commit e4f9d6013820d1eba1432d51dd1c5795759aa77f upstream.

When btree_split_beneath() splits a node to two new children, it will
allocate two blocks: left and right.  If right block's allocation
failed, the left block will be unlocked and marked dirty.  If this
happened, the left block'ss content is zero, because it wasn't
initialized with the btree struct before the attempot to allocate the
right block.  Upon return, when flushing the left block to disk, the
validator will fail when check this block.  Then a BUG_ON is raised.

Fix this by completely initializing the left block before allocating and
initializing the right block.

Fixes: 4dcb8b57df359 ("dm btree: fix leak of bufio-backed block in btree_split_beneath error path")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu &lt;zhangxiaoxu5@huawei.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm btree: fix serious bug in btree_split_beneath()</title>
<updated>2018-01-23T18:50:16Z</updated>
<author>
<name>Joe Thornber</name>
<email>thornber@redhat.com</email>
</author>
<published>2017-12-20T09:56:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9c7755af771ac1b4ef1fc0e552749aa80d23af32'/>
<id>urn:sha1:9c7755af771ac1b4ef1fc0e552749aa80d23af32</id>
<content type='text'>
commit bc68d0a43560e950850fc69b58f0f8254b28f6d6 upstream.

When inserting a new key/value pair into a btree we walk down the spine of
btree nodes performing the following 2 operations:

  i) space for a new entry
  ii) adjusting the first key entry if the new key is lower than any in the node.

If the _root_ node is full, the function btree_split_beneath() allocates 2 new
nodes, and redistibutes the root nodes entries between them.  The root node is
left with 2 entries corresponding to the 2 new nodes.

btree_split_beneath() then adjusts the spine to point to one of the two new
children.  This means the first key is never adjusted if the new key was lower,
ie. operation (ii) gets missed out.  This can result in the new key being
'lost' for a period; until another low valued key is inserted that will uncover
it.

This is a serious bug, and quite hard to make trigger in normal use.  A
reproducing test case ("thin create devices-in-reverse-order") is
available as part of the thin-provision-tools project:
  https://github.com/jthornber/thin-provisioning-tools/blob/master/functional-tests/device-mapper/dm-tests.scm#L593

Fix the issue by changing btree_split_beneath() so it no longer adjusts
the spine.  Instead it unlocks both the new nodes, and lets the main
loop in btree_insert_raw() relock the appropriate one and make any
neccessary adjustments.

Reported-by: Monty Pavel &lt;monty_pavel@sina.com&gt;
Signed-off-by: Joe Thornber &lt;thornber@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm space map disk: fix some book keeping in the disk space map</title>
<updated>2017-05-25T12:30:08Z</updated>
<author>
<name>Joe Thornber</name>
<email>ejt@redhat.com</email>
</author>
<published>2017-05-15T13:45:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d3df9403c0758f35538bb172578d1c6dcf552622'/>
<id>urn:sha1:d3df9403c0758f35538bb172578d1c6dcf552622</id>
<content type='text'>
commit 0377a07c7a035e0d033cd8b29f0cb15244c0916a upstream.

When decrementing the reference count for a block, the free count wasn't
being updated if the reference count went to zero.

Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm btree: fix for dm_btree_find_lowest_key()</title>
<updated>2017-05-25T12:30:07Z</updated>
<author>
<name>Vinothkumar Raja</name>
<email>vinraja@cs.stonybrook.edu</email>
</author>
<published>2017-04-07T02:09:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fa499b361bd4771fed7b94c367edf102e3c078a6'/>
<id>urn:sha1:fa499b361bd4771fed7b94c367edf102e3c078a6</id>
<content type='text'>
commit 7d1fedb6e96a960aa91e4ff70714c3fb09195a5a upstream.

dm_btree_find_lowest_key() is giving incorrect results.  find_key()
traverses the btree correctly for finding the highest key, but there is
an error in the way it traverses the btree for retrieving the lowest
key.  dm_btree_find_lowest_key() fetches the first key of the rightmost
block of the btree instead of fetching the first key from the leftmost
block.

Fix this by conditionally passing the correct parameter to value64()
based on the @find_highest flag.

Signed-off-by: Erez Zadok &lt;ezk@fsl.cs.sunysb.edu&gt;
Signed-off-by: Vinothkumar Raja &lt;vinraja@cs.stonybrook.edu&gt;
Signed-off-by: Nidhi Panpalia &lt;npanpalia@cs.stonybrook.edu&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>dm space map metadata: fix 'struct sm_metadata' leak on failed create</title>
<updated>2017-01-06T10:16:15Z</updated>
<author>
<name>Benjamin Marzinski</name>
<email>bmarzins@redhat.com</email>
</author>
<published>2016-11-30T23:56:14Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=701ec6e5cea7ed6508999a25934af807767fe545'/>
<id>urn:sha1:701ec6e5cea7ed6508999a25934af807767fe545</id>
<content type='text'>
commit 314c25c56c1ee5026cf99c570bdfe01847927acb upstream.

In dm_sm_metadata_create() we temporarily change the dm_space_map
operations from 'ops' (whose .destroy function deallocates the
sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't).

If dm_sm_metadata_create() fails in sm_ll_new_metadata() or
sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls
dm_sm_destroy() with the intention of freeing the sm_metadata, but it
doesn't (because the dm_space_map operations is still set to
'bootstrap_ops').

Fix this by setting the dm_space_map operations back to 'ops' if
dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'.

Signed-off-by: Benjamin Marzinski &lt;bmarzins@redhat.com&gt;
Acked-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
