<feed xmlns='http://www.w3.org/2005/Atom'>
<title>wireguard-linux/drivers/md/md-cluster.c, branch update-toolchain</title>
<subtitle>WireGuard for the Linux kernel</subtitle>
<id>https://git.zx2c4.com/wireguard-linux/atom/drivers/md/md-cluster.c?h=update-toolchain</id>
<link rel='self' href='https://git.zx2c4.com/wireguard-linux/atom/drivers/md/md-cluster.c?h=update-toolchain'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/'/>
<updated>2024-07-22T18:32:05Z</updated>
<entry>
<title>Merge tag 'for-6.11/block-20240722' of git://git.kernel.dk/linux</title>
<updated>2024-07-22T18:32:05Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-22T18:32:05Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=7d080fa867092c1db078dd72d70cb256642f7b18'/>
<id>urn:sha1:7d080fa867092c1db078dd72d70cb256642f7b18</id>
<content type='text'>
Pull more block updates from Jens Axboe:

 - MD fixes via Song:
     - md-cluster fixes (Heming Zhao)
     - raid1 fix (Mateusz Jończyk)

 - s390/dasd module description (Jeff)

 - Series cleaning up and hardening the blk-mq debugfs flag handling
   (John, Christoph)

 - blk-cgroup cleanup (Xiu)

 - Error polled IO attempts if backend doesn't support it (hexue)

 - Fix for an sbitmap hang (Yang)

* tag 'for-6.11/block-20240722' of git://git.kernel.dk/linux: (23 commits)
  blk-cgroup: move congestion_count to struct blkcg
  sbitmap: fix io hung due to race on sbitmap_word::cleared
  block: avoid polling configuration errors
  block: Catch possible entries missing from rqf_name[]
  block: Simplify definition of RQF_NAME()
  block: Use enum to define RQF_x bit indexes
  block: Catch possible entries missing from cmd_flag_name[]
  block: Catch possible entries missing from alloc_policy_name[]
  block: Catch possible entries missing from hctx_flag_name[]
  block: Catch possible entries missing from hctx_state_name[]
  block: Catch possible entries missing from blk_queue_flag_name[]
  block: Make QUEUE_FLAG_x as an enum
  block: Relocate BLK_MQ_MAX_DEPTH
  block: Relocate BLK_MQ_CPU_WORK_BATCH
  block: remove QUEUE_FLAG_STOPPED
  block: Add missing entry to hctx_flag_name[]
  block: Add zone write plugging entry to rqf_name[]
  block: Add missing entries from cmd_flag_name[]
  s390/dasd: fix error checks in dasd_copy_pair_store()
  s390/dasd: add missing MODULE_DESCRIPTION() macros
  ...
</content>
</entry>
<entry>
<title>Merge tag 'dlm-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm</title>
<updated>2024-07-17T19:16:22Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-17T19:16:22Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=f097ef0e7625f70844ddaba60ca43d421db5b1b0'/>
<id>urn:sha1:f097ef0e7625f70844ddaba60ca43d421db5b1b0</id>
<content type='text'>
Pull dlm updates from David Teigland:

 - New flag DLM_LSFL_SOFTIRQ_SAFE can be set by code using dlm to
   indicate callbacks can be run from softirq

 - Change md-cluster to set DLM_LSFL_SOFTIRQ_SAFE

 - Clean up for previous changes, e.g. unused code and parameters

 - Remove custom pre-allocation of rsb structs which is unnecessary with
   kmem caches

 - Change idr to xarray for lkb structs in use

 - Change idr to xarray for rsb structs being recovered

 - Change outdated naming related to internal rsb states

 - Fix some incorrect add/remove of rsb on scan list

 - Use rcu to free rsb structs

* tag 'dlm-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
  dlm: add rcu_barrier before destroy kmem cache
  dlm: remove DLM_LSFL_SOFTIRQ from exflags
  fs: dlm: remove unused struct 'dlm_processed_nodes'
  md-cluster: use DLM_LSFL_SOFTIRQ for dlm_new_lockspace()
  dlm: implement LSFL_SOFTIRQ_SAFE
  dlm: introduce DLM_LSFL_SOFTIRQ_SAFE
  dlm: use LSFL_FS to check for kernel lockspace
  dlm: use rcu to avoid an extra rsb struct lookup
  dlm: fix add_scan and del_scan usage
  dlm: change list and timer names
  dlm: move recover idr to xarray datastructure
  dlm: move lkb idr to xarray datastructure
  dlm: drop own rsb pre allocation mechanism
  dlm: remove ls_local_handle from struct dlm_ls
  dlm: remove unused parameter in dlm_midcomms_addr
  dlm: don't kref_init rsbs created for toss list
  dlm: remove scand leftovers
</content>
</entry>
<entry>
<title>md-cluster: fix no recovery job when adding/re-adding a disk</title>
<updated>2024-07-12T01:30:18Z</updated>
<author>
<name>Heming Zhao</name>
<email>heming.zhao@suse.com</email>
</author>
<published>2024-07-09T10:41:20Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=35a0a409fa269c287c4378f1aefe84ae8b5211a1'/>
<id>urn:sha1:35a0a409fa269c287c4378f1aefe84ae8b5211a1</id>
<content type='text'>
The commit db5e653d7c9f ("md: delay choosing sync action to
md_start_sync()") delays the start of the sync action. In a
clustered environment, this will cause another node to first
activate the spare disk and skip recovery. As a result, no
nodes will perform recovery when a disk is added or re-added.

Before db5e653d7c9f:

```
   node1                                node2
----------------------------------------------------------------
md_check_recovery
 + md_update_sb
 |  sendmsg: METADATA_UPDATED
 + md_choose_sync_action           process_metadata_update
 |  remove_and_add_spares           //node1 has not finished adding
 + call mddev-&gt;sync_work            //the spare disk:do nothing

md_start_sync
 starts md_do_sync

md_do_sync
 + grabbed resync_lockres:DLM_LOCK_EX
 + do syncing job

md_check_recovery
 sendmsg: METADATA_UPDATED
                                 process_metadata_update
                                   //activate spare disk

                                 ... ...

                                 md_do_sync
                                  waiting to grab resync_lockres:EX
```

After db5e653d7c9f:

(note: if 'cmd:idle' sets MD_RECOVERY_INTR after md_check_recovery
starts md_start_sync, setting the INTR action will exacerbate the
delay in node1 calling the md_do_sync function.)

```
   node1                                node2
----------------------------------------------------------------
md_check_recovery
 + md_update_sb
 |  sendmsg: METADATA_UPDATED
 + calls mddev-&gt;sync_work         process_metadata_update
                                   //node1 has not finished adding
                                   //the spare disk:do nothing

md_start_sync
 + md_choose_sync_action
 |  remove_and_add_spares
 + calls md_do_sync

md_check_recovery
 md_update_sb
  sendmsg: METADATA_UPDATED
                                  process_metadata_update
                                    //activate spare disk

  ... ...                         ... ...

                                  md_do_sync
                                   + grabbed resync_lockres:EX
                                   + raid1_sync_request skip sync under
				     conf-&gt;fullsync:0
md_do_sync
 1. waiting to grab resync_lockres:EX
 2. when node1 could grab EX lock,
    node1 will skip resync under recovery_offset:MaxSector
```

How to trigger:

```(commands @node1)
 # to easily watch the recovery status
echo 2000 &gt; /proc/sys/dev/raid/speed_limit_max
ssh root@node2 "echo 2000 &gt; /proc/sys/dev/raid/speed_limit_max"

mdadm -CR /dev/md0 -l1 -b clustered -n 2 /dev/sda /dev/sdb --assume-clean
ssh root@node2 mdadm -A /dev/md0 /dev/sda /dev/sdb
mdadm --manage /dev/md0 --fail /dev/sda --remove /dev/sda
mdadm --manage /dev/md0 --add /dev/sdc

=== "cat /proc/mdstat" on both node, there are no recovery action. ===
```

How to fix:

because md layer code logic is hard to restore for speeding up sync job
on local node, we add new cluster msg to pending the another node to
active disk.

Signed-off-by: Heming Zhao &lt;heming.zhao@suse.com&gt;
Reviewed-by: Su Yue &lt;glass.su@suse.com&gt;
Acked-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240709104120.22243-2-heming.zhao@suse.com
</content>
</entry>
<entry>
<title>md-cluster: fix hanging issue while a new disk adding</title>
<updated>2024-07-12T01:30:17Z</updated>
<author>
<name>Heming Zhao</name>
<email>heming.zhao@suse.com</email>
</author>
<published>2024-07-09T10:41:19Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=fff42f213824fa434a4b6cf906b4331fe6e9302b'/>
<id>urn:sha1:fff42f213824fa434a4b6cf906b4331fe6e9302b</id>
<content type='text'>
The commit 1bbe254e4336 ("md-cluster: check for timeout while a
new disk adding") is correct in terms of code syntax but not
suite real clustered code logic.

When a timeout occurs while adding a new disk, if recv_daemon()
bypasses the unlock for ack_lockres:CR, another node will be waiting
to grab EX lock. This will cause the cluster to hang indefinitely.

How to fix:

1. In dlm_lock_sync(), change the wait behaviour from forever to a
   timeout, This could avoid the hanging issue when another node
   fails to handle cluster msg. Another result of this change is
   that if another node receives an unknown msg (e.g. a new msg_type),
   the old code will hang, whereas the new code will timeout and fail.
   This could help cluster_md handle new msg_type from different
   nodes with different kernel/module versions (e.g. The user only
   updates one leg's kernel and monitors the stability of the new
   kernel).
2. The old code for __sendmsg() always returns 0 (success) under the
   design (must successfully unlock -&gt;message_lockres). This commit
   makes this function return an error number when an error occurs.

Fixes: 1bbe254e4336 ("md-cluster: check for timeout while a new disk adding")
Signed-off-by: Heming Zhao &lt;heming.zhao@suse.com&gt;
Reviewed-by: Su Yue &lt;glass.su@suse.com&gt;
Acked-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240709104120.22243-1-heming.zhao@suse.com
</content>
</entry>
<entry>
<title>md-cluster: Constify struct md_cluster_operations</title>
<updated>2024-07-04T06:20:27Z</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2024-06-23T20:17:54Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=1f4a72ff00cafa74b43b0c8a37573c78f86ed1a8'/>
<id>urn:sha1:1f4a72ff00cafa74b43b0c8a37573c78f86ed1a8</id>
<content type='text'>
'struct md_cluster_operations' is not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  51941	   1442	     80	  53463	   d0d7	drivers/md/md-cluster.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  52133	   1246	     80	  53459	   d0d3	drivers/md/md-cluster.o

Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/3727f3ce9693cae4e62ae6778ea13971df805479.1719173852.git.christophe.jaillet@wanadoo.fr
</content>
</entry>
<entry>
<title>md-cluster: use DLM_LSFL_SOFTIRQ for dlm_new_lockspace()</title>
<updated>2024-06-11T18:30:37Z</updated>
<author>
<name>Alexander Aring</name>
<email>aahringo@redhat.com</email>
</author>
<published>2024-06-03T21:55:58Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=5ce02000eb29db98dc2909b1a346f68acdd9db80'/>
<id>urn:sha1:5ce02000eb29db98dc2909b1a346f68acdd9db80</id>
<content type='text'>
Use the recently added DLM_LSFL_SOFTIRQ flag in dlm_new_lockspace(),
signalling the ability to handle callbacks being run from softirq
context.  The md-cluster callback functions only call complete(),
which is suitable for softirq.  This should make dlm lock request
completions more efficient by avoiding the workqueue context switch.

Acked-by: Heming Zhao &lt;heming.zhao@suse.com&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Alexander Aring &lt;aahringo@redhat.com&gt;
Signed-off-by: David Teigland &lt;teigland@redhat.com&gt;
</content>
</entry>
<entry>
<title>md-cluster: check for timeout while a new disk adding</title>
<updated>2023-10-12T16:16:19Z</updated>
<author>
<name>Denis Plotnikov</name>
<email>den-plotnikov@yandex-team.ru</email>
</author>
<published>2023-09-25T12:59:40Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=1bbe254e4336c0944dd4fb6f0b8c9665b81de50f'/>
<id>urn:sha1:1bbe254e4336c0944dd4fb6f0b8c9665b81de50f</id>
<content type='text'>
A new disk adding may end up with timeout and a new disk won't be added.
Add returning the error in that case.

Found by Linux Verification Center (linuxtesting.org) with SVACE

Signed-off-by: Denis Plotnikov &lt;den-plotnikov@yandex-team.ru&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230925125940.1542506-1-den-plotnikov@yandex-team.ru
</content>
</entry>
<entry>
<title>md: Hold mddev-&gt;reconfig_mutex when trying to get mddev-&gt;sync_thread</title>
<updated>2023-08-15T16:40:26Z</updated>
<author>
<name>Li Lingfeng</name>
<email>lilingfeng3@huawei.com</email>
</author>
<published>2023-08-03T07:17:11Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=7eb8ff02c1df279bf7f7f29b866beb655a9eebe9'/>
<id>urn:sha1:7eb8ff02c1df279bf7f7f29b866beb655a9eebe9</id>
<content type='text'>
Commit ba9d9f1a707f ("Revert "md: unlock mddev before reap sync_thread in
action_store"") removed the scenario of calling md_unregister_thread()
without holding mddev-&gt;reconfig_mutex, so add a lock holding check before
acquiring mddev-&gt;sync_thread by passing mdev to md_unregister_thread().

Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Link: https://lore.kernel.org/r/20230803071711.2546560-1-lilingfeng@huaweicloud.com
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
</content>
</entry>
<entry>
<title>md: protect md_thread with rcu</title>
<updated>2023-06-13T22:25:39Z</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-05-23T02:10:17Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=4469315439827290923fce4f3f672599cabeb366'/>
<id>urn:sha1:4469315439827290923fce4f3f672599cabeb366</id>
<content type='text'>
Currently, there are many places that md_thread can be accessed without
protection, following are known scenarios that can cause
null-ptr-dereference or uaf:

1) sync_thread that is allocated and started from md_start_sync()
2) mddev-&gt;thread can be accessed directly from timeout_store() and
   md_bitmap_daemon_work()
3) md_unregister_thread() from action_store().

Currently, a global spinlock 'pers_lock' is borrowed to protect
'mddev-&gt;thread' in some places, this problem can be fixed likewise,
however, use a global lock for all the cases is not good.

Fix this problem by protecting all md_thread with rcu.

Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230523021017.3048783-6-yukuai1@huaweicloud.com
</content>
</entry>
<entry>
<title>fs: dlm: remove DLM_LSFL_FS from uapi</title>
<updated>2022-08-23T19:54:54Z</updated>
<author>
<name>Alexander Aring</name>
<email>aahringo@redhat.com</email>
</author>
<published>2022-08-15T19:43:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=12cda13cfd5310bbfefdfe32a82489228e2e0381'/>
<id>urn:sha1:12cda13cfd5310bbfefdfe32a82489228e2e0381</id>
<content type='text'>
The DLM_LSFL_FS flag is set in lockspaces created directly
for a kernel user, as opposed to those lockspaces created
for user space applications.  The user space libdlm allowed
this flag to be set for lockspaces created from user space,
but then used by a kernel user.  No kernel user has ever
used this method, so remove the ability to do it.

Signed-off-by: Alexander Aring &lt;aahringo@redhat.com&gt;
Signed-off-by: David Teigland &lt;teigland@redhat.com&gt;
</content>
</entry>
</feed>
