io_uring: cleanup fixed file data table references

[linux-2.6-microblaze.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 67a3950..b041b66 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -354,12 +354,6 @@ static inline struct epitem *ep_item_from_epqueue(poll_table *p)
        return container_of(p, struct ep_pqueue, pt)->epi;
 }
 
-/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
-static inline int ep_op_has_event(int op)
-{
-       return op != EPOLL_CTL_DEL;
-}
-
 /* Initialize the poll safe wake up structure */
 static void ep_nested_calls_init(struct nested_calls *ncalls)
 {
@@ -2074,27 +2068,28 @@ 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 inline int epoll_mutex_lock(struct mutex *mutex, int depth,
+                                  bool nonblock)
+{
+       if (!nonblock) {
+               mutex_lock_nested(mutex, depth);
+               return 0;
+       }
+       if (mutex_trylock(mutex))
+               return 0;
+       return -EAGAIN;
+}
+
+int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
+                bool nonblock)
 {
        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 +2107,7 @@ 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 +2123,11 @@ 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;
        }
 
@@ -2157,13 +2152,17 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
         * deep wakeup paths from forming in parallel through multiple
         * EPOLL_CTL_ADD operations.
         */
-       mutex_lock_nested(&ep->mtx, 0);
+       error = epoll_mutex_lock(&ep->mtx, 0, nonblock);
+       if (error)
+               goto error_tgt_fput;
        if (op == EPOLL_CTL_ADD) {
                if (!list_empty(&f.file->f_ep_links) ||
                                                is_file_epoll(tf.file)) {
-                       full_check = 1;
                        mutex_unlock(&ep->mtx);
-                       mutex_lock(&epmutex);
+                       error = epoll_mutex_lock(&epmutex, 0, nonblock);
+                       if (error)
+                               goto error_tgt_fput;
+                       full_check = 1;
                        if (is_file_epoll(tf.file)) {
                                error = -ELOOP;
                                if (ep_loop_check(ep, tf.file) != 0) {
@@ -2173,10 +2172,19 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
                        } else
                                list_add(&tf.file->f_tfile_llink,
                                                        &tfile_check_list);
-                       mutex_lock_nested(&ep->mtx, 0);
+                       error = epoll_mutex_lock(&ep->mtx, 0, nonblock);
+                       if (error) {
+out_del:
+                               list_del(&tf.file->f_tfile_llink);
+                               goto error_tgt_fput;
+                       }
                        if (is_file_epoll(tf.file)) {
                                tep = tf.file->private_data;
-                               mutex_lock_nested(&tep->mtx, 1);
+                               error = epoll_mutex_lock(&tep->mtx, 1, nonblock);
+                               if (error) {
+                                       mutex_unlock(&ep->mtx);
+                                       goto out_del;
+                               }
                        }
                }
        }
@@ -2192,8 +2200,8 @@ 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 +2216,8 @@ 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;
@@ -2231,6 +2239,23 @@ error_return:
        return error;
 }
 
+/*
+ * 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, false);
+}
+
 /*
  * Implement the event wait interface for the eventpoll file. It is the kernel
  * part of the user space epoll_wait(2).