The patch titled
usb: libusual: locking cleanup
has been added to the -mm tree. Its filename is
usb-libusual-locking-cleanup.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: usb: libusual: locking cleanup
From: Daniel Walker <dwalker@xxxxxxxxxx>
I converted the usu_init_notify semaphore to normal mutex usage, and it
should still prevent the request_module before the init routine is
complete. Before it acted more like a complete, now the mutex protects two
distinct section from running at the same time.
Signed-off-by: Daniel Walker <dwalker@xxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Pete Zaitcev <zaitcev@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/storage/libusual.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff -puN drivers/usb/storage/libusual.c~usb-libusual-locking-cleanup drivers/usb/storage/libusual.c
--- a/drivers/usb/storage/libusual.c~usb-libusual-locking-cleanup
+++ a/drivers/usb/storage/libusual.c
@@ -9,6 +9,7 @@
#include <linux/usb_usual.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
+#include <linux/mutex.h>
/*
*/
@@ -30,7 +31,7 @@ static atomic_t usu_bias = ATOMIC_INIT(U
#define BIAS_NAME_SIZE (sizeof("usb-storage"))
static const char *bias_names[3] = { "none", "usb-storage", "ub" };
-static struct semaphore usu_init_notify;
+static DEFINE_MUTEX(usu_probe_mutex);
static DECLARE_COMPLETION(usu_end_notify);
static atomic_t total_threads = ATOMIC_INIT(0);
@@ -178,10 +179,7 @@ static int usu_probe_thread(void *arg)
int rc;
unsigned long flags;
- /* A completion does not work here because it's counted. */
- down(&usu_init_notify);
- up(&usu_init_notify);
-
+ mutex_lock(&usu_probe_mutex);
rc = request_module(bias_names[type]);
spin_lock_irqsave(&usu_lock, flags);
if (rc == 0 && (st->fls & USU_MOD_FL_PRESENT) == 0) {
@@ -194,6 +192,7 @@ static int usu_probe_thread(void *arg)
}
st->fls &= ~USU_MOD_FL_THREAD;
spin_unlock_irqrestore(&usu_lock, flags);
+ mutex_unlock(&usu_probe_mutex);
complete_and_exit(&usu_end_notify, 0);
}
@@ -204,10 +203,9 @@ static int __init usb_usual_init(void)
{
int rc;
- sema_init(&usu_init_notify, 0);
-
+ mutex_lock(&usu_probe_mutex);
rc = usb_register(&usu_driver);
- up(&usu_init_notify);
+ mutex_unlock(&usu_probe_mutex);
return rc;
}
_
Patches currently in -mm which might be from dwalker@xxxxxxxxxx are
ps3-vuart-fix-error-path-locking.patch
driver-base-memory-semaphore-to-mutex.patch
git-dvb.patch
usb-microtek-remove-unused-semaphore.patch
usb-libusual-locking-cleanup.patch
prism54-remove-questionable-down_interruptible-usage.patch
git-x86.patch
page-allocator-clean-up-pcp-draining-functions-swsusp-fix.patch
page-allocator-clean-up-pcp-draining-functions-swsusp-fix-fix.patch
drivers-char-tty_ioc-remove-pty_sem.patch
drivers-isdn-i4l-isdn_ttyc-remove-write_sem.patch
unix98-allocated_ptys_lock-semaphore-to-mutex.patch
docs-kernel-locking-convert-semaphore-references.patch
stopmachine-semaphore-to-mutex.patch
stopmachine-semaphore-to-mutex-fix.patch
amiga-serial-driver-port_write_mutex-fixup.patch
docs-convert-kref-semaphore-to-mutex.patch
isapnp-driver-semaphore-to-mutex.patch
isapnp-driver-semaphore-to-mutex-fix.patch
isapnp-driver-semaphore-to-mutex-fix-fix.patch
profile-likely-unlikely-macros.patch
profile-likely-unlikely-macros-fix.patch
-
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