Summing up the discussion above, I suggest the following patch for TFR()
macro refactoring. (The patch is sequential to the first one I introduced
in the start of the discussion).
>From 6318bee052900aa93bba6620b53c7cb2290e5001 Mon Sep 17 00:00:00 2001
From: Nikita Ivanov <niva...@cloudlinux.com>
Date: Mon, 8 Aug 2022 09:30:34 +0300
Subject: [PATCH] Refactoring: rename TFR() to TEMP_FAILURE_RETRY()
glibc's unistd.h header provides the same macro with the
subtle difference in type casting. Adjust macro name to the
common standard and define conditionally.
Signed-off-by: Nikita Ivanov <niva...@cloudlinux.com>
---
chardev/char-fd.c | 2 +-
chardev/char-pipe.c | 12 +++++++++---
hw/9pfs/9p-local.c | 6 ++++--
include/qemu/osdep.h | 6 ++++--
net/l2tpv3.c | 8 +++++---
net/tap-linux.c | 2 +-
net/tap.c | 10 ++++++----
os-posix.c | 2 +-
qga/commands-posix.c | 2 +-
tests/qtest/libqtest.c | 2 +-
util/main-loop.c | 2 +-
util/osdep.c | 2 +-
12 files changed, 35 insertions(+), 21 deletions(-)
diff --git a/chardev/char-fd.c b/chardev/char-fd.c
index cf78454841..7f5ed9aba3 100644
--- a/chardev/char-fd.c
+++ b/chardev/char-fd.c
@@ -198,7 +198,7 @@ int qmp_chardev_open_file_source(char *src, int flags,
Error **errp)
{
int fd = -1;
- TFR(fd = qemu_open_old(src, flags, 0666));
+ TEMP_FAILURE_RETRY(fd = qemu_open_old(src, flags, 0666));
if (fd == -1) {
error_setg_file_open(errp, errno, src);
}
diff --git a/chardev/char-pipe.c b/chardev/char-pipe.c
index 66d3b85091..aed97e306b 100644
--- a/chardev/char-pipe.c
+++ b/chardev/char-pipe.c
@@ -131,8 +131,12 @@ static void qemu_chr_open_pipe(Chardev *chr,
filename_in = g_strdup_printf("%s.in", filename);
filename_out = g_strdup_printf("%s.out", filename);
- TFR(fd_in = qemu_open_old(filename_in, O_RDWR | O_BINARY));
- TFR(fd_out = qemu_open_old(filename_out, O_RDWR | O_BINARY));
+ TEMP_FAILURE_RETRY(
+ fd_in = qemu_open_old(filename_in, O_RDWR | O_BINARY)
+ );
+ TEMP_FAILURE_RETRY(
+ fd_out = qemu_open_old(filename_out, O_RDWR | O_BINARY)
+ );
g_free(filename_in);
g_free(filename_out);
if (fd_in < 0 || fd_out < 0) {
@@ -142,7 +146,9 @@ static void qemu_chr_open_pipe(Chardev *chr,
if (fd_out >= 0) {
close(fd_out);
}
- TFR(fd_in = fd_out = qemu_open_old(filename, O_RDWR | O_BINARY));
+ TEMP_FAILURE_RETRY(
+ fd_in = fd_out = qemu_open_old(filename, O_RDWR | O_BINARY)
+ );
if (fd_in < 0) {
error_setg_file_open(errp, errno, filename);
return;
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index c90ab947ba..e803c05d0c 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -470,7 +470,7 @@ static ssize_t local_readlink(FsContext *fs_ctx,
V9fsPath *fs_path,
if (fd == -1) {
return -1;
}
- TFR(tsize = read(fd, (void *)buf, bufsz));
+ TEMP_FAILURE_RETRY(tsize = read(fd, (void *)buf, bufsz));
close_preserve_errno(fd);
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
@@ -906,7 +906,9 @@ static int local_symlink(FsContext *fs_ctx, const char
*oldpath,
}
/* Write the oldpath (target) to the file. */
oldpath_size = strlen(oldpath);
- TFR(write_size = write(fd, (void *)oldpath, oldpath_size));
+ TEMP_FAILURE_RETRY(
+ write_size = write(fd, (void *)oldpath, oldpath_size)
+ );
close_preserve_errno(fd);
if (write_size != oldpath_size) {
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index b1c161c035..55f2927d8b 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -242,8 +242,10 @@ void QEMU_ERROR("code path is reachable")
#if !defined(ESHUTDOWN)
#define ESHUTDOWN 4099
#endif
-
-#define TFR(expr) do { if ((expr) != -1) break; } while (errno == EINTR)
+#if !defined(TEMP_FAILURE_RETRY)
+#define TEMP_FAILURE_RETRY(expr) \
+ do { if ((expr) != -1) break; } while (errno == EINTR)
+#endif
/* time_t may be either 32 or 64 bits depending on the host OS, and
* can be either signed or unsigned, so we can't just hardcode a
diff --git a/net/l2tpv3.c b/net/l2tpv3.c
index adfdbdb84c..9594047ddb 100644
--- a/net/l2tpv3.c
+++ b/net/l2tpv3.c
@@ -240,7 +240,7 @@ static ssize_t
net_l2tpv3_receive_dgram_iov(NetClientState *nc,
message.msg_control = NULL;
message.msg_controllen = 0;
message.msg_flags = 0;
- TFR(ret = sendmsg(s->fd, &message, 0));
+ TEMP_FAILURE_RETRY(ret = sendmsg(s->fd, &message, 0));
if (ret > 0) {
ret -= s->offset;
} else if (ret == 0) {
@@ -283,7 +283,7 @@ static ssize_t net_l2tpv3_receive_dgram(NetClientState
*nc,
message.msg_control = NULL;
message.msg_controllen = 0;
message.msg_flags = 0;
- TFR(ret = sendmsg(s->fd, &message, 0));
+ TEMP_FAILURE_RETRY(ret = sendmsg(s->fd, &message, 0));
if (ret > 0) {
ret -= s->offset;
} else if (ret == 0) {
@@ -430,7 +430,9 @@ static void net_l2tpv3_send(void *opaque)
msgvec = s->msgvec + s->queue_head;
if (target_count > 0) {
- TFR(count = recvmmsg(s->fd, msgvec, target_count, MSG_DONTWAIT,
NULL));
+ TEMP_FAILURE_RETRY(
+ count = recvmmsg(s->fd, msgvec, target_count, MSG_DONTWAIT,
NULL)
+ );
if (count < 0) {
/* Recv error - we still need to flush packets here,
* (re)set queue head to current position
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 304ff45071..e1a10c77af 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -45,7 +45,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
int len = sizeof(struct virtio_net_hdr);
unsigned int features;
- TFR(fd = open(PATH_NET_TUN, O_RDWR));
+ TEMP_FAILURE_RETRY(fd = open(PATH_NET_TUN, O_RDWR));
if (fd < 0) {
error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN);
return -1;
diff --git a/net/tap.c b/net/tap.c
index b047eca8b5..9fa0a8fa21 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -102,7 +102,7 @@ static ssize_t tap_write_packet(TAPState *s, const
struct iovec *iov, int iovcnt
{
ssize_t len;
- TFR(len = writev(s->fd, iov, iovcnt));
+ TEMP_FAILURE_RETRY(len = writev(s->fd, iov, iovcnt));
if (len == -1 && errno == EAGAIN) {
tap_write_poll(s, true);
@@ -575,7 +575,7 @@ static int net_bridge_run_helper(const char *helper,
const char *bridge,
close(sv[1]);
- TFR(fd = recv_fd(sv[0]));
+ TEMP_FAILURE_RETRY(fd = recv_fd(sv[0]));
saved_errno = errno;
close(sv[0]);
@@ -647,8 +647,10 @@ static int net_tap_init(const NetdevTapOptions *tap,
int *vnet_hdr,
vnet_hdr_required = 0;
}
- TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
- mq_required, errp));
+ TEMP_FAILURE_RETRY(
+ fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
+ mq_required, errp)
+ );
if (fd < 0) {
return -1;
}
diff --git a/os-posix.c b/os-posix.c
index 321fc4bd13..e9918b9788 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -266,7 +266,7 @@ void os_setup_post(void)
error_report("not able to chdir to /: %s", strerror(errno));
exit(1);
}
- TFR(fd = qemu_open_old("/dev/null", O_RDWR));
+ TEMP_FAILURE_RETRY(fd = qemu_open_old("/dev/null", O_RDWR));
if (fd == -1) {
exit(1);
}
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 90f83aa9b6..5dd2c4a3e5 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -68,7 +68,7 @@ static void ga_wait_child(pid_t pid, int *status, Error
**errp)
*status = 0;
- TFR(rpid = waitpid(pid, status, 0));
+ TEMP_FAILURE_RETRY(rpid = waitpid(pid, status, 0));
if (rpid == -1) {
error_setg_errno(errp, errno, "failed to wait for child (pid: %d)",
diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index 8c159eacf5..031f71cbba 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -140,7 +140,7 @@ void qtest_kill_qemu(QTestState *s)
/* Skip wait if qtest_probe_child already reaped. */
if (pid != -1) {
kill(pid, SIGTERM);
- TFR(pid = waitpid(s->qemu_pid, &s->wstatus, 0));
+ TEMP_FAILURE_RETRY(pid = waitpid(s->qemu_pid, &s->wstatus, 0));
assert(pid == s->qemu_pid);
s->qemu_pid = -1;
}
diff --git a/util/main-loop.c b/util/main-loop.c
index 58e14db2d4..3a21f39792 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -64,7 +64,7 @@ static void sigfd_handler(void *opaque)
ssize_t len;
while (1) {
- TFR(len = read(fd, &info, sizeof(info)));
+ TEMP_FAILURE_RETRY(len = read(fd, &info, sizeof(info)));
if (len == -1 && errno == EAGAIN) {
break;
diff --git a/util/osdep.c b/util/osdep.c
index d35c473ac7..e5d2225738 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -244,7 +244,7 @@ static int qemu_lock_fcntl(int fd, int64_t start,
int64_t len, int fl_type)
.l_type = fl_type,
};
qemu_probe_lock_ops();
- TFR(ret = fcntl(fd, fcntl_op_setlk, &fl));
+ TEMP_FAILURE_RETRY(ret = fcntl(fd, fcntl_op_setlk, &fl));
return ret == -1 ? -errno : 0;
}
--
2.37.1
On Fri, Aug 5, 2022 at 2:40 PM Peter Maydell <peter.mayd...@linaro.org>
wrote:
> On Fri, 5 Aug 2022 at 12:27, Marc-André Lureau
> <marcandre.lur...@redhat.com> wrote:
> > On Fri, Aug 5, 2022 at 3:11 PM Christian Schoenebeck
> > <qemu_...@crudebyte.com> wrote:
> > > I was thinking the same as Marc-André before:
> > >
> > > commit 1dacd88ddcf33eb6ed044c4080e3ef5e3de4b6b6
> > > Author: Marc-André Lureau <marcandre.lur...@redhat.com>
> > > Date: Wed Mar 23 19:57:27 2022 +0400
> > >
> > > include: move TFR to osdep.h
> > >
> > > The macro requires EINTR, which has its header included in osdep.h.
> > >
> > > (Not sure what TFR stands for, perhaps "Test For Retry". Rename it
> ?)
> > >
> > > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > > Message-Id: <20220323155743.1585078-17-marcandre.lur...@redhat.com
> >
> > > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> > >
> > > Wouldn't it make sense to first rename TFR() to something like
> > > RETRY_ON_EINTR() and then doing this consolidation here on top?
> >
> > Apparently TFR often stands for "Temp Failure Retry" (looking at
> > github code search)
> >
> > LOOP_WHILE_EINTR ?
>
> At the risk of getting into bikeshedding, since glibc's unistd.h
> defines a TEMP_FAILURE_RETRY() macro for this purpose, maybe we
> should use that, with a thing in osdep.h for "provide this macro
> if the system headers don't [ie musl, BSDs, Windows, etc]" ?
>
> (There is a subtle difference between our TFR() and the glibc
> TEMP_FAILURE_RETRY(): TEMP_FAILURE_RETRY() casts the result
> of the expr to 'long int' before comparing for equality with -1.)
>
> More generally, I think we should either use this macro rather
> more widely, or get rid of it entirely. The current situation
> where we use it in some of the net/tap code and a few chardevs
> and basically nowhere else is not very satisfactory.
>
> thanks
> -- PMM
>
--
Best Regards,
*Nikita Ivanov* | C developer
*Telephone:* +79140870696
*Telephone:* +79015053149
