eventpoll: abstract out epoll_ctl() handler

No functional changes in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 67a3950..cd848e8 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2074,27 +2074,15 @@ SYSCALL_DEFINE1(epoll_create, int, size)
        return do_epoll_create(0);
 }
 
-/*
- * The following function implements the controller interface for
- * the eventpoll file that enables the insertion/removal/change of
- * file descriptors inside the interest set.
- */
-SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
-               struct epoll_event __user *, event)
+static int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds)
 {
        int error;
        int full_check = 0;
        struct fd f, tf;
        struct eventpoll *ep;
        struct epitem *epi;
-       struct epoll_event epds;
        struct eventpoll *tep = NULL;
 
-       error = -EFAULT;
-       if (ep_op_has_event(op) &&
-           copy_from_user(&epds, event, sizeof(struct epoll_event)))
-               goto error_return;
-
        error = -EBADF;
        f = fdget(epfd);
        if (!f.file)
@@ -2112,7 +2100,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
 
        /* Check if EPOLLWAKEUP is allowed */
        if (ep_op_has_event(op))
-               ep_take_care_of_epollwakeup(&epds);
+               ep_take_care_of_epollwakeup(epds);
 
        /*
         * We have to check that the file structure underneath the file descriptor
@@ -2128,11 +2116,11 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
         * so EPOLLEXCLUSIVE is not allowed for a EPOLL_CTL_MOD operation.
         * Also, we do not currently supported nested exclusive wakeups.
         */
-       if (ep_op_has_event(op) && (epds.events & EPOLLEXCLUSIVE)) {
+       if (ep_op_has_event(op) && (epds->events & EPOLLEXCLUSIVE)) {
                if (op == EPOLL_CTL_MOD)
                        goto error_tgt_fput;
                if (op == EPOLL_CTL_ADD && (is_file_epoll(tf.file) ||
-                               (epds.events & ~EPOLLEXCLUSIVE_OK_BITS)))
+                               (epds->events & ~EPOLLEXCLUSIVE_OK_BITS)))
                        goto error_tgt_fput;
        }
 
@@ -2192,8 +2180,8 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
        switch (op) {
        case EPOLL_CTL_ADD:
                if (!epi) {
-                       epds.events |= EPOLLERR | EPOLLHUP;
-                       error = ep_insert(ep, &epds, tf.file, fd, full_check);
+                       epds->events |= EPOLLERR | EPOLLHUP;
+                       error = ep_insert(ep, epds, tf.file, fd, full_check);
                } else
                        error = -EEXIST;
                if (full_check)
@@ -2208,8 +2196,8 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
        case EPOLL_CTL_MOD:
                if (epi) {
                        if (!(epi->event.events & EPOLLEXCLUSIVE)) {
-                               epds.events |= EPOLLERR | EPOLLHUP;
-                               error = ep_modify(ep, epi, &epds);
+                               epds->events |= EPOLLERR | EPOLLHUP;
+                               error = ep_modify(ep, epi, epds);
                        }
                } else
                        error = -ENOENT;
@@ -2232,6 +2220,23 @@ error_return:
 }
 
 /*
+ * The following function implements the controller interface for
+ * the eventpoll file that enables the insertion/removal/change of
+ * file descriptors inside the interest set.
+ */
+SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
+               struct epoll_event __user *, event)
+{
+       struct epoll_event epds;
+
+       if (ep_op_has_event(op) &&
+           copy_from_user(&epds, event, sizeof(struct epoll_event)))
+               return -EFAULT;
+
+       return do_epoll_ctl(epfd, op, fd, &epds);
+}
+
+/*
  * Implement the event wait interface for the eventpoll file. It is the kernel
  * part of the user space epoll_wait(2).
  */