The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x f448451aa62d54be16acb0034223c17e0d12bc69 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024082656-shield-daily-d746@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

f448451aa62d ("mptcp: pm: remove mptcp_pm_remove_subflow()") ef34a6ea0cab ("mptcp: pm: re-using ID of unused flushed subflows") edd8b5d868a4 ("mptcp: pm: re-using ID of unused removed subflows") 4b317e0eb287 ("mptcp: fix NL PM announced address accounting") 9bbec87ecfe8 ("mptcp: unify pm get_local_id interfaces") dc886bce753c ("mptcp: export local_address") 8b1c94da1e48 ("mptcp: only send RM_ADDR in nl_cmd_remove") c157bbe776b7 ("mptcp: allow the in kernel PM to set MPC subflow priority") d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE") 9ab4807c84a4 ("mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE") 982f17ba1a25 ("mptcp: netlink: split mptcp_pm_parse_addr into two functions") 8b20137012d9 ("mptcp: read attributes of addr entries managed by userspace PMs") 4638de5aefe5 ("mptcp: handle local addrs announced by userspace PMs") c682bf536cf4 ("mptcp: add pm_nl_pernet helpers") 4cf86ae84c71 ("mptcp: strict local address ID selection") d045b9eb95a9 ("mptcp: introduce implicit endpoints") 6fa0174a7c86 ("mptcp: more careful RM_ADDR generation") 7d9bf018f907 ("selftests: mptcp: update output info of chk_rm_nr") 90d930882139 ("mptcp: constify a bunch of of helpers") 33397b83eee6 ("selftests: mptcp: add backup with port testcase")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f448451aa62d54be16acb0034223c17e0d12bc69 Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" matttbe@kernel.org Date: Mon, 19 Aug 2024 21:45:25 +0200 Subject: [PATCH] mptcp: pm: remove mptcp_pm_remove_subflow()

This helper is confusing. It is in pm.c, but it is specific to the in-kernel PM and it cannot be used by the userspace one. Also, it simply calls one in-kernel specific function with the PM lock, while the similar mptcp_pm_remove_addr() helper requires the PM lock.

What's left is the pr_debug(), which is not that useful, because a similar one is present in the only function called by this helper:

mptcp_pm_nl_rm_subflow_received()

After these modifications, this helper can be marked as 'static', and the lock can be taken only once in mptcp_pm_flush_addrs_and_subflows().

Note that it is not a bug fix, but it will help backporting the following commits.

Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-7-38035d40de5b@... Signed-off-by: Jakub Kicinski kuba@kernel.org

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 23bb89c94e90..925123e99889 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -60,16 +60,6 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_ return 0; }

-int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list) -{ - pr_debug("msk=%p, rm_list_nr=%d", msk, rm_list->nr); - - spin_lock_bh(&msk->pm.lock); - mptcp_pm_nl_rm_subflow_received(msk, rm_list); - spin_unlock_bh(&msk->pm.lock); - return 0; -} - /* path manager event handlers */

void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 2c26696b820e..44fc1c5959ac 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -857,8 +857,8 @@ static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk) mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR); }

-void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, - const struct mptcp_rm_list *rm_list) +static void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, + const struct mptcp_rm_list *rm_list) { mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW); } @@ -1471,7 +1471,9 @@ static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net, !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));

if (remove_subflow) { - mptcp_pm_remove_subflow(msk, &list); + spin_lock_bh(&msk->pm.lock); + mptcp_pm_nl_rm_subflow_received(msk, &list); + spin_unlock_bh(&msk->pm.lock); } else if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { /* If the subflow has been used, but now closed */ spin_lock_bh(&msk->pm.lock); @@ -1617,18 +1619,14 @@ static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk, alist.ids[alist.nr++] = entry->addr.id; }

+ spin_lock_bh(&msk->pm.lock); if (alist.nr) { - spin_lock_bh(&msk->pm.lock); msk->pm.add_addr_signaled -= alist.nr; mptcp_pm_remove_addr(msk, &alist); - spin_unlock_bh(&msk->pm.lock); } - if (slist.nr) - mptcp_pm_remove_subflow(msk, &slist); - + mptcp_pm_nl_rm_subflow_received(msk, &slist); /* Reset counters: maybe some subflows have been removed before */ - spin_lock_bh(&msk->pm.lock); bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); msk->pm.local_addr_used = 0; spin_unlock_bh(&msk->pm.lock); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 60c6b073d65f..a1c1b0ff1ce1 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -1026,7 +1026,6 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr, bool echo); int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list); -int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list); void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list);

void mptcp_free_local_addr_list(struct mptcp_sock *msk); @@ -1133,8 +1132,6 @@ static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflo

void __init mptcp_pm_nl_init(void); void mptcp_pm_nl_work(struct mptcp_sock *msk); -void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, - const struct mptcp_rm_list *rm_list); unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk); unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk); unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);