vfs: umount_begin BKL pushdown

[safe/jmp/linux-2.6] / fs / eventfd.c

diff --git a/fs/eventfd.c b/fs/eventfd.c
index bd420e6..2a701d5 100644 (file)
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -28,6 +28,7 @@ struct eventfd_ctx {
         * issue a wakeup.
         */
        __u64 count;
+       unsigned int flags;
 };
 
 /*
@@ -50,7 +51,7 @@ int eventfd_signal(struct file *file, int n)
                n = (int) (ULLONG_MAX - ctx->count);
        ctx->count += n;
        if (waitqueue_active(&ctx->wqh))
-               wake_up_locked(&ctx->wqh);
+               wake_up_locked_poll(&ctx->wqh, POLLIN);
        spin_unlock_irqrestore(&ctx->wqh.lock, flags);
 
        return n;
@@ -87,22 +88,20 @@ static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count,
 {
        struct eventfd_ctx *ctx = file->private_data;
        ssize_t res;
-       __u64 ucnt;
+       __u64 ucnt = 0;
        DECLARE_WAITQUEUE(wait, current);
 
        if (count < sizeof(ucnt))
                return -EINVAL;
        spin_lock_irq(&ctx->wqh.lock);
        res = -EAGAIN;
-       ucnt = ctx->count;
-       if (ucnt > 0)
+       if (ctx->count > 0)
                res = sizeof(ucnt);
        else if (!(file->f_flags & O_NONBLOCK)) {
                __add_wait_queue(&ctx->wqh, &wait);
                for (res = 0;;) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        if (ctx->count > 0) {
-                               ucnt = ctx->count;
                                res = sizeof(ucnt);
                                break;
                        }
@@ -117,10 +116,11 @@ static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count,
                __remove_wait_queue(&ctx->wqh, &wait);
                __set_current_state(TASK_RUNNING);
        }
-       if (res > 0) {
-               ctx->count = 0;
+       if (likely(res > 0)) {
+               ucnt = (ctx->flags & EFD_SEMAPHORE) ? 1 : ctx->count;
+               ctx->count -= ucnt;
                if (waitqueue_active(&ctx->wqh))
-                       wake_up_locked(&ctx->wqh);
+                       wake_up_locked_poll(&ctx->wqh, POLLOUT);
        }
        spin_unlock_irq(&ctx->wqh.lock);
        if (res > 0 && put_user(ucnt, (__u64 __user *) buf))
@@ -166,10 +166,10 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c
                __remove_wait_queue(&ctx->wqh, &wait);
                __set_current_state(TASK_RUNNING);
        }
-       if (res > 0) {
+       if (likely(res > 0)) {
                ctx->count += ucnt;
                if (waitqueue_active(&ctx->wqh))
-                       wake_up_locked(&ctx->wqh);
+                       wake_up_locked_poll(&ctx->wqh, POLLIN);
        }
        spin_unlock_irq(&ctx->wqh.lock);
 
@@ -198,12 +198,16 @@ struct file *eventfd_fget(int fd)
        return file;
 }
 
-asmlinkage long sys_eventfd2(unsigned int count, int flags)
+SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)
 {
        int fd;
        struct eventfd_ctx *ctx;
 
-       if (flags & ~EFD_CLOEXEC)
+       /* Check the EFD_* constants for consistency.  */
+       BUILD_BUG_ON(EFD_CLOEXEC != O_CLOEXEC);
+       BUILD_BUG_ON(EFD_NONBLOCK != O_NONBLOCK);
+
+       if (flags & ~EFD_FLAGS_SET)
                return -EINVAL;
 
        ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
@@ -212,19 +216,20 @@ asmlinkage long sys_eventfd2(unsigned int count, int flags)
 
        init_waitqueue_head(&ctx->wqh);
        ctx->count = count;
+       ctx->flags = flags;
 
        /*
         * When we call this, the initialization must be complete, since
         * anon_inode_getfd() will install the fd.
         */
        fd = anon_inode_getfd("[eventfd]", &eventfd_fops, ctx,
-                             flags & O_CLOEXEC);
+                             flags & EFD_SHARED_FCNTL_FLAGS);
        if (fd < 0)
                kfree(ctx);
        return fd;
 }
 
-asmlinkage long sys_eventfd(unsigned int count)
+SYSCALL_DEFINE1(eventfd, unsigned int, count)
 {
        return sys_eventfd2(count, 0);
 }