systemd/0134-resolved-handle-EINTR-...

80 lines
2.7 KiB
Diff

From 471b70bca8f1a77b1d5402e190b00a61aa0d58b0 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 22 Nov 2022 12:28:19 +0100
Subject: [PATCH] resolved: handle -EINTR returned from fd_wait_for_event()
better
We might get signals for various reasons (for example, somebody asking
us to reload caches via a signal), hence let's handle this gracefully.
(cherry picked from commit 6d66a221685c15798e796d9738f73fdb1fdccdb2)
Related: #2137584
---
src/resolve/resolved-manager.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index f62efa87aa..1c9048670b 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -868,11 +868,14 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
}
static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
+ usec_t end;
int r;
assert(fd >= 0);
assert(mh);
+ end = usec_add(now(CLOCK_MONOTONIC), SEND_TIMEOUT_USEC);
+
for (;;) {
if (sendmsg(fd, mh, flags) >= 0)
return 0;
@@ -881,20 +884,26 @@ static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
if (errno != EAGAIN)
return -errno;
- r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
- if (r < 0)
+ r = fd_wait_for_event(fd, POLLOUT, LESS_BY(end, now(CLOCK_MONOTONIC)));
+ if (r < 0) {
+ if (ERRNO_IS_TRANSIENT(r))
+ continue;
return r;
+ }
if (r == 0)
return -ETIMEDOUT;
}
}
static int write_loop(int fd, void *message, size_t length) {
+ usec_t end;
int r;
assert(fd >= 0);
assert(message);
+ end = usec_add(now(CLOCK_MONOTONIC), SEND_TIMEOUT_USEC);
+
for (;;) {
if (write(fd, message, length) >= 0)
return 0;
@@ -903,9 +912,12 @@ static int write_loop(int fd, void *message, size_t length) {
if (errno != EAGAIN)
return -errno;
- r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
- if (r < 0)
+ r = fd_wait_for_event(fd, POLLOUT, LESS_BY(end, now(CLOCK_MONOTONIC)));
+ if (r < 0) {
+ if (ERRNO_IS_TRANSIENT(r))
+ continue;
return r;
+ }
if (r == 0)
return -ETIMEDOUT;
}