From 44b550d88b267320459d518c0743a241ab2108fa Mon Sep 17 00:00:00 2001 From: Nan Li Date: Fri, 1 May 2026 09:08:44 +0800 Subject: net/rds: handle zerocopy send cleanup before the message is queued A zerocopy send can fail after user pages have been pinned but before the message is attached to the sending socket. The purge path currently infers zerocopy state from rm->m_rs, so an unqueued message can be cleaned up as if it owned normal payload pages. However, zerocopy ownership is really determined by the presence of op_mmp_znotifier, regardless of whether the message has reached the socket queue. Capture op_mmp_znotifier up front in rds_message_purge() and use it as the cleanup discriminator. If the message is already associated with a socket, keep the existing completion path. Otherwise, drop the pinned page accounting directly and release the notifier before putting the payload pages. This keeps early send failure cleanup consistent with the zerocopy lifetime rules without changing the normal queued completion path. Fixes: 0cebaccef3ac ("rds: zerocopy Tx support.") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Co-developed-by: Xiao Liu Signed-off-by: Xiao Liu Signed-off-by: Nan Li Signed-off-by: Ren Wei Reviewed-by: Allison Henderson Link: https://patch.msgid.link/d2ea98a6313d5467bac00f7c9fef8c7acddb9258.1777550074.git.tonanli66@gmail.com Signed-off-by: Paolo Abeni --- net/rds/message.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/net/rds/message.c b/net/rds/message.c index eaa6f22601a4..25fedcb3cd00 100644 --- a/net/rds/message.c +++ b/net/rds/message.c @@ -131,24 +131,34 @@ static void rds_rm_zerocopy_callback(struct rds_sock *rs, */ static void rds_message_purge(struct rds_message *rm) { + struct rds_znotifier *znotifier; unsigned long i, flags; - bool zcopy = false; + bool zcopy; if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags))) return; spin_lock_irqsave(&rm->m_rs_lock, flags); + znotifier = rm->data.op_mmp_znotifier; + rm->data.op_mmp_znotifier = NULL; + zcopy = !!znotifier; + if (rm->m_rs) { struct rds_sock *rs = rm->m_rs; - if (rm->data.op_mmp_znotifier) { - zcopy = true; - rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier); + if (znotifier) { + rds_rm_zerocopy_callback(rs, znotifier); rds_wake_sk_sleep(rs); - rm->data.op_mmp_znotifier = NULL; } sock_put(rds_rs_to_sk(rs)); rm->m_rs = NULL; + } else if (znotifier) { + /* + * Zerocopy can fail before the message is queued on the + * socket, so there is no rs to carry the notification. + */ + mm_unaccount_pinned_pages(&znotifier->z_mmp); + kfree(rds_info_from_znotifier(znotifier)); } spin_unlock_irqrestore(&rm->m_rs_lock, flags); -- cgit v1.2.3