From: Ingo Molnar Convert fs/9p/mux.c from semaphore to mutex. NOTE: fixed locking bugs in the process - the code was using semaphores the other way around. Signed-off-by: Ingo Molnar Cc: Eric Van Hensbergen Signed-off-by: Andrew Morton --- fs/9p/mux.c | 11 ++++++----- 1 files changed, 6 insertions(+), 5 deletions(-) diff -puN fs/9p/mux.c~convert-fs-9p-to-mutexes-fix-locking-bugs fs/9p/mux.c --- 25/fs/9p/mux.c~convert-fs-9p-to-mutexes-fix-locking-bugs Thu Jan 12 16:35:23 2006 +++ 25-akpm/fs/9p/mux.c Thu Jan 12 16:35:23 2006 @@ -31,6 +31,7 @@ #include #include #include +#include #include "debug.h" #include "v9fs.h" @@ -110,7 +111,7 @@ static void v9fs_pollwait(struct file *f static u16 v9fs_mux_get_tag(struct v9fs_mux_data *); static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16); -static DECLARE_MUTEX(v9fs_mux_task_lock); +static DEFINE_MUTEX(v9fs_mux_task_lock); static struct workqueue_struct *v9fs_mux_wq; static int v9fs_mux_num; @@ -166,7 +167,7 @@ static int v9fs_mux_poll_start(struct v9 dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num, v9fs_mux_poll_task_num); - up(&v9fs_mux_task_lock); + mutex_lock(&v9fs_mux_task_lock); n = v9fs_mux_calc_poll_procs(v9fs_mux_num + 1); if (n > v9fs_mux_poll_task_num) { @@ -225,7 +226,7 @@ static int v9fs_mux_poll_start(struct v9 } v9fs_mux_num++; - down(&v9fs_mux_task_lock); + mutex_unlock(&v9fs_mux_task_lock); return 0; } @@ -235,7 +236,7 @@ static void v9fs_mux_poll_stop(struct v9 int i; struct v9fs_mux_poll_task *vpt; - up(&v9fs_mux_task_lock); + mutex_lock(&v9fs_mux_task_lock); vpt = m->poll_task; list_del(&m->mux_list); for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { @@ -252,7 +253,7 @@ static void v9fs_mux_poll_stop(struct v9 v9fs_mux_poll_task_num--; } v9fs_mux_num--; - down(&v9fs_mux_task_lock); + mutex_unlock(&v9fs_mux_task_lock); } /** _