kernel/linux.git/fs/dlm/midcomms.c, branch v7.2-rc2

dlm: init per node debugfs before add to node hash

2026-05-08T13:38:03+00:00

Avoiding potential issues when a node is added to the hash but the debugfs is not NULL or IS_ERR() so a potential iteration over the hash and debugfs_remove() will not fail like in dlm_midcomms_exit(). However dlm_midcomms_exit() will be called in module init/exit function and the hash should be empty anyway at those stages. We change the behavior as cleanup to avoid potential issues. Reported-by: Ginger Closes: https://lore.kernel.org/gfs2/CAGp+u1ZE7UsQ4sSUHBKQXU8x3M_jwK=ek1urSjEtd3jXQGFmVg@mail.gmail.com Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix add msg handle in send_queue ordered

2026-05-08T13:38:03+00:00

In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older sequence numbers that are ordered in the tail of "node->send_queue". The side effects of not having it correct ordered regarding "before(mh->seq, seq)" are refcounting issues and use-after free. I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don't experienced any refcounting with the sending buffer issues anymore. Fixes: 489d8e559c659 ("fs: dlm: add reliable connection if reconnect") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: use hlist_for_each_entry_srcu for SRCU protected lists

2026-05-08T13:38:03+00:00

The connection and node hash tables in DLM are protected by SRCU, but the code currently uses hlist_for_each_entry_rcu() for traversal. While this works functionally, it is semantically incorrect and triggers warnings when RCU lockdep debugging is enabled, as it expects regular RCU read-side critical sections. This patch replaces the incorrect macros with hlist_for_each_entry_srcu() and adds the appropriate lockdep expressions using srcu_read_lock_held() to ensure consistency with the underlying locking mechanism. Signed-off-by: Li RongQing Acked-by: Alexander Aring Signed-off-by: Alexander Aring Signed-off-by: David Teigland

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

dlm: remove unused parameter in dlm_midcomms_addr

2024-05-31T16:04:54+00:00

This patch removes an parameter which is currently not used by dlm_midcomms_addr(). Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: use spin_lock_bh for message processing

2024-04-09T16:45:23+00:00

Use spin_lock_bh for all spinlocks involved in message processing, in preparation for softirq message processing. DLM lock requests from user space involve dlm processing in user context, in addition to the standard kernel context, necessitating bh variants. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: remove allocation parameter in msg allocation

2024-04-09T14:58:14+00:00

Remove the context parameter for message allocations and always use GFP_ATOMIC. This prepares for softirq message processing. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: Simplify the allocation of slab caches in dlm_midcomms_cache_create

2024-04-01T18:31:12+00:00

Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by: Kunwu Chan Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix no ack after final message

2023-10-12T20:20:55+00:00

In case of an final DLM message we can't should not send an ack out after the final message. This patch moves the ack message before the messages will be transmitted. If it's the final message and the receiving node turns into DLM_CLOSED state another ack messages will being received and turning the receiving node into DLM_ESTABLISHED again. Fixes: 1696c75f1864 ("fs: dlm: add send ack threshold and append acks to msgs") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: be sure we reset all nodes at forced shutdown

2023-10-12T20:20:48+00:00

In case we running in a force shutdown in either midcomms or lowcomms implementation we will make sure we reset all per midcomms node information. Fixes: 63e711b08160 ("fs: dlm: create midcomms nodes when configure") Signed-off-by: Alexander Aring Signed-off-by: David Teigland