[PATCH 2/4] um: os_set_fd_block: Return old blocking mode

Richard Weinberger
2022-01-01T21:58:33Z

This will be needed when we restore the old mode upon exit.
The function now returns < 0 in case of an error, 1 if O_NONBLOCK
was set, 0 otherwise.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
arch/um/drivers/chan_kern.c | 8 ++++----
arch/um/drivers/chan_user.c | 2 +-
arch/um/drivers/mconsole_kern.c | 2 +-
arch/um/drivers/ubd_user.c | 2 +-
arch/um/drivers/xterm.c | 2 +-
arch/um/os-Linux/file.c | 5 ++++-
6 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 62997055c454..86be115b5890 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -83,7 +83,7 @@ static const struct chan_ops not_configged_ops = {

static int open_one_chan(struct chan *chan)
{
- int fd, err;
+ int fd, ret;

if (chan->opened)
return 0;
@@ -95,10 +95,10 @@ static int open_one_chan(struct chan *chan)
if (fd < 0)
return fd;

- err = os_set_fd_block(fd, 0);
- if (err) {
+ ret = os_set_fd_block(fd, 0);
+ if (ret < 0) {
(*chan->ops->close)(fd, chan->data);
- return err;
+ return ret;
}

chan->fd = fd;
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 6040817c036f..b449656cd5f8 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -257,7 +257,7 @@ static int winch_tramp(int fd, struct tty_port *port, int *fd_out,
}

err = os_set_fd_block(*fd_out, 0);
- if (err) {
+ if (err < 0) {
printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
"non-blocking.\n");
goto out_close;
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 6ead1e240457..8000914f9cd4 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -732,7 +732,7 @@ static int __init mconsole_init(void)
printk(KERN_ERR "Failed to initialize management console\n");
return 1;
}
- if (os_set_fd_block(sock, 0))
+ if (os_set_fd_block(sock, 0) < 0)
goto out;

register_reboot_notifier(&reboot_notifier);
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index a1afe414ce48..a930a254826b 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -42,7 +42,7 @@ int start_io_thread(unsigned long sp, int *fd_out)

err = os_set_fd_block(*fd_out, 0);
err = os_set_fd_block(kernel_fd, 0);
- if (err) {
+ if (err < 0) {
printk("start_io_thread - failed to set nonblocking I/O.\n");
goto out_close;
}
diff --git a/arch/um/drivers/xterm.c b/arch/um/drivers/xterm.c
index 87ca4a47cd66..01be81c25266 100644
--- a/arch/um/drivers/xterm.c
+++ b/arch/um/drivers/xterm.c
@@ -161,7 +161,7 @@ static int xterm_open(int input, int output, int primary, void *d,
}

err = os_set_fd_block(new, 0);
- if (err) {
+ if (err < 0) {
printk(UM_KERN_ERR "xterm_open : failed to set xterm "
"descriptor non-blocking, err = %d\n", -err);
goto out_close2;
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index e4421dbc4c36..af2b3cba2c93 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -445,11 +445,14 @@ int os_clear_fd_async(int fd)
int os_set_fd_block(int fd, int blocking)
{
int flags;
+ int oldmode;

flags = fcntl(fd, F_GETFL);
if (flags < 0)
return -errno;

+ oldmode = !!(flags & O_NONBLOCK);
+
if (blocking)
flags &= ~O_NONBLOCK;
else
@@ -458,7 +461,7 @@ int os_set_fd_block(int fd, int blocking)
if (fcntl(fd, F_SETFL, flags) < 0)
return -errno;

- return 0;
+ return oldmode;
}

int os_accept_connection(int fd)
--
2.26.2