The ubd io thread and UML kernel thread share the same errno, which
can lead to conflicts when both call syscalls concurrently. Switch to
the pthread-based helper to address this issue.
Signed-off-by: Tiwei Bie <tiwei....@antgroup.com>
---
arch/um/drivers/ubd.h | 6 ++++--
arch/um/drivers/ubd_kern.c | 25 +++++++++++--------------
arch/um/drivers/ubd_user.c | 14 +++++++-------
3 files changed, 22 insertions(+), 23 deletions(-)
diff --git a/arch/um/drivers/ubd.h b/arch/um/drivers/ubd.h
index f016fe15499f..2985c14661f4 100644
--- a/arch/um/drivers/ubd.h
+++ b/arch/um/drivers/ubd.h
@@ -7,8 +7,10 @@
#ifndef __UM_UBD_USER_H
#define __UM_UBD_USER_H
-extern int start_io_thread(unsigned long sp, int *fds_out);
-extern int io_thread(void *arg);
+#include <os.h>
+
+int start_io_thread(struct os_helper_thread **td_out, int *fd_out);
+void *io_thread(void *arg);
extern int kernel_fd;
extern int ubd_read_poll(int timeout);
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 0b1e61f72fb3..4de6613e7468 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -474,12 +474,12 @@ static irqreturn_t ubd_intr(int irq, void *dev)
}
/* Only changed by ubd_init, which is an initcall. */
-static int io_pid = -1;
+static struct os_helper_thread *io_td;
static void kill_io_thread(void)
{
- if(io_pid != -1)
- os_kill_process(io_pid, 1);
+ if (io_td)
+ os_kill_helper_thread(io_td);
}
__uml_exitcall(kill_io_thread);
@@ -1104,8 +1104,8 @@ static int __init ubd_init(void)
late_initcall(ubd_init);
-static int __init ubd_driver_init(void){
- unsigned long stack;
+static int __init ubd_driver_init(void)
+{
int err;
/* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
@@ -1114,13 +1114,11 @@ static int __init ubd_driver_init(void){
/* Letting ubd=sync be like using ubd#s= instead of ubd#= is
* enough. So use anyway the io thread. */
}
- stack = alloc_stack(0, 0);
- io_pid = start_io_thread(stack + PAGE_SIZE, &thread_fd);
- if(io_pid < 0){
+ err = start_io_thread(&io_td, &thread_fd);
+ if (err < 0) {
printk(KERN_ERR
"ubd : Failed to start I/O thread (errno = %d) - "
- "falling back to synchronous I/O\n", -io_pid);
- io_pid = -1;
+ "falling back to synchronous I/O\n", -err);
return 0;
}
err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
@@ -1496,12 +1494,11 @@ int kernel_fd = -1;
/* Only changed by the io thread. XXX: currently unused. */
static int io_count;
-int io_thread(void *arg)
+void *io_thread(void *arg)
{
int n, count, written, res;
- os_set_pdeathsig();
- os_fix_helper_signals();
+ os_fix_helper_thread_signals();
while(1){
n = bulk_req_safe_read(
@@ -1543,5 +1540,5 @@ int io_thread(void *arg)
} while (written < n);
}
- return 0;
+ return NULL;
}
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index b4f8b8e60564..c5e6545f6fcf 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -25,9 +25,9 @@
static struct pollfd kernel_pollfd;
-int start_io_thread(unsigned long sp, int *fd_out)
+int start_io_thread(struct os_helper_thread **td_out, int *fd_out)
{
- int pid, fds[2], err;
+ int fds[2], err;
err = os_pipe(fds, 1, 1);
if(err < 0){
@@ -47,14 +47,14 @@ int start_io_thread(unsigned long sp, int *fd_out)
goto out_close;
}
- pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM, NULL);
- if(pid < 0){
- err = -errno;
- printk("start_io_thread - clone failed : errno = %d\n", errno);
+ err = os_run_helper_thread(td_out, io_thread, NULL);
+ if (err < 0) {
+ printk("%s - failed to run helper thread, err = %d\n",
+ __func__, -err);
goto out_close;
}
- return(pid);
+ return 0;
out_close:
os_close_file(fds[0]);
--
2.34.1
