[PATCH v2 1/3] net/9p: handle replies racing with interrupted RPCs
From: Ze Tan <hidden>
Date: 2026-07-16 07:31:44
Also in:
lkml, v9fs
Subsystem:
9p file system, the rest · Maintainers:
Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet, Linus Torvalds
A reply can arrive after io_wait_event_killable() reports an interruption but before the client starts cancellation. In that case the request is already complete and must not be flushed or returned as an error. Recheck REQ_STATUS_RCVD before entering the flush path in both regular and zero-copy RPCs. Signed-off-by: Ze Tan <redacted> --- net/9p/client.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/net/9p/client.c b/net/9p/client.c
index ef64546c6d52..b9860ccb224b 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c@@ -612,6 +612,11 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...) err = req->t_err; } if (err == -ERESTARTSYS && c->status == Connected) { + if (READ_ONCE(req->status) == REQ_STATUS_RCVD) { + err = 0; + goto recalc_sigpending; + } + p9_debug(P9_DEBUG_MUX, "flushing\n"); sigpending = 1; clear_thread_flag(TIF_SIGPENDING);
@@ -697,6 +702,11 @@ static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type, err = req->t_err; } if (err == -ERESTARTSYS && c->status == Connected) { + if (READ_ONCE(req->status) == REQ_STATUS_RCVD) { + err = 0; + goto recalc_sigpending; + } + p9_debug(P9_DEBUG_MUX, "flushing\n"); sigpending = 1; clear_thread_flag(TIF_SIGPENDING);
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2.43.0