[PATCH] Remove eventpoll macro obfuscation

This patch gets rid of some macro obfuscation from fs/eventpoll.c by
removing slab allocator wrappers and converting macros to static inline
functions.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 9900e33..6ab1dd0 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -101,57 +101,6 @@
 /* Maximum number of poll wake up nests we are allowing */
 #define EP_MAX_POLLWAKE_NESTS 4
 
 /* Maximum number of poll wake up nests we are allowing */
 #define EP_MAX_POLLWAKE_NESTS 4
 

-/* Macro to allocate a "struct epitem" from the slab cache */
-#define EPI_MEM_ALLOC()        (struct epitem *) kmem_cache_alloc(epi_cache, SLAB_KERNEL)
-
-/* Macro to free a "struct epitem" to the slab cache */
-#define EPI_MEM_FREE(p) kmem_cache_free(epi_cache, p)
-
-/* Macro to allocate a "struct eppoll_entry" from the slab cache */
-#define PWQ_MEM_ALLOC()        (struct eppoll_entry *) kmem_cache_alloc(pwq_cache, SLAB_KERNEL)
-
-/* Macro to free a "struct eppoll_entry" to the slab cache */
-#define PWQ_MEM_FREE(p) kmem_cache_free(pwq_cache, p)
-
-/* Fast test to see if the file is an evenpoll file */
-#define IS_FILE_EPOLL(f) ((f)->f_op == &eventpoll_fops)
-
-/* Setup the structure that is used as key for the rb-tree */
-#define EP_SET_FFD(p, f, d) do { (p)->file = (f); (p)->fd = (d); } while (0)
-
-/* Compare rb-tree keys */
-#define EP_CMP_FFD(p1, p2) ((p1)->file > (p2)->file ? +1: \
-                           ((p1)->file < (p2)->file ? -1: (p1)->fd - (p2)->fd))
-
-/* Special initialization for the rb-tree node to detect linkage */
-#define EP_RB_INITNODE(n) (n)->rb_parent = (n)
-
-/* Removes a node from the rb-tree and marks it for a fast is-linked check */
-#define EP_RB_ERASE(n, r) do { rb_erase(n, r); (n)->rb_parent = (n); } while (0)
-
-/* Fast check to verify that the item is linked to the main rb-tree */
-#define EP_RB_LINKED(n) ((n)->rb_parent != (n))
-
-/*
- * Remove the item from the list and perform its initialization.
- * This is useful for us because we can test if the item is linked
- * using "EP_IS_LINKED(p)".
- */
-#define EP_LIST_DEL(p) do { list_del(p); INIT_LIST_HEAD(p); } while (0)
-
-/* Tells us if the item is currently linked */
-#define EP_IS_LINKED(p) (!list_empty(p))
-
-/* Get the "struct epitem" from a wait queue pointer */
-#define EP_ITEM_FROM_WAIT(p) ((struct epitem *) container_of(p, struct eppoll_entry, wait)->base)
-
-/* Get the "struct epitem" from an epoll queue wrapper */
-#define EP_ITEM_FROM_EPQUEUE(p) (container_of(p, struct ep_pqueue, pt)->epi)
-
-/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
-#define EP_OP_HASH_EVENT(op) ((op) != EPOLL_CTL_DEL)
-
-

 struct epoll_filefd {
        struct file *file;
        int fd;
 struct epoll_filefd {
        struct file *file;
        int fd;


@@ -357,6 +306,82 @@ static struct dentry_operations eventpollfs_dentry_operations = {
 
 
 
 
 
 

+/* Fast test to see if the file is an evenpoll file */
+static inline int is_file_epoll(struct file *f)
+{
+       return f->f_op == &eventpoll_fops;
+}
+
+/* Setup the structure that is used as key for the rb-tree */
+static inline void ep_set_ffd(struct epoll_filefd *ffd,
+                             struct file *file, int fd)
+{
+       ffd->file = file;
+       ffd->fd = fd;
+}
+
+/* Compare rb-tree keys */
+static inline int ep_cmp_ffd(struct epoll_filefd *p1,
+                            struct epoll_filefd *p2)
+{
+       return (p1->file > p2->file ? +1:
+               (p1->file < p2->file ? -1 : p1->fd - p2->fd));
+}
+
+/* Special initialization for the rb-tree node to detect linkage */
+static inline void ep_rb_initnode(struct rb_node *n)
+{
+       n->rb_parent = n;
+}
+
+/* Removes a node from the rb-tree and marks it for a fast is-linked check */
+static inline void ep_rb_erase(struct rb_node *n, struct rb_root *r)
+{
+       rb_erase(n, r);
+       n->rb_parent = n;
+}
+
+/* Fast check to verify that the item is linked to the main rb-tree */
+static inline int ep_rb_linked(struct rb_node *n)
+{
+       return n->rb_parent != n;
+}
+
+/*
+ * Remove the item from the list and perform its initialization.
+ * This is useful for us because we can test if the item is linked
+ * using "ep_is_linked(p)".
+ */
+static inline void ep_list_del(struct list_head *p)
+{
+       list_del(p);
+       INIT_LIST_HEAD(p);
+}
+
+/* Tells us if the item is currently linked */
+static inline int ep_is_linked(struct list_head *p)
+{
+       return !list_empty(p);
+}
+
+/* Get the "struct epitem" from a wait queue pointer */
+static inline struct epitem * ep_item_from_wait(wait_queue_t *p)
+{
+       return container_of(p, struct eppoll_entry, wait)->base;
+}
+
+/* Get the "struct epitem" from an epoll queue wrapper */
+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_hash_event(int op)
+{
+       return op != EPOLL_CTL_DEL;
+}
+

 /* Initialize the poll safe wake up structure */
 static void ep_poll_safewake_init(struct poll_safewake *psw)
 {
 /* Initialize the poll safe wake up structure */
 static void ep_poll_safewake_init(struct poll_safewake *psw)
 {


@@ -456,7 +481,7 @@ void eventpoll_release_file(struct file *file)
                epi = list_entry(lsthead->next, struct epitem, fllink);
 
                ep = epi->ep;
                epi = list_entry(lsthead->next, struct epitem, fllink);
 
                ep = epi->ep;

-               EP_LIST_DEL(&epi->fllink);
+               ep_list_del(&epi->fllink);

                down_write(&ep->sem);
                ep_remove(ep, epi);
                up_write(&ep->sem);
                down_write(&ep->sem);
                ep_remove(ep, epi);
                up_write(&ep->sem);


@@ -534,7 +559,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
                     current, epfd, op, fd, event));
 
        error = -EFAULT;
                     current, epfd, op, fd, event));
 
        error = -EFAULT;

-       if (EP_OP_HASH_EVENT(op) &&
+       if (ep_op_hash_event(op) &&

            copy_from_user(&epds, event, sizeof(struct epoll_event)))
                goto eexit_1;
 
            copy_from_user(&epds, event, sizeof(struct epoll_event)))
                goto eexit_1;
 


@@ -560,7 +585,7 @@ sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
         * adding an epoll file descriptor inside itself.
         */
        error = -EINVAL;
         * adding an epoll file descriptor inside itself.
         */
        error = -EINVAL;

-       if (file == tfile || !IS_FILE_EPOLL(file))
+       if (file == tfile || !is_file_epoll(file))

                goto eexit_3;
 
        /*
                goto eexit_3;
 
        /*


@@ -656,7 +681,7 @@ asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events,
         * the user passed to us _is_ an eventpoll file.
         */
        error = -EINVAL;
         * the user passed to us _is_ an eventpoll file.
         */
        error = -EINVAL;

-       if (!IS_FILE_EPOLL(file))
+       if (!is_file_epoll(file))

                goto eexit_2;
 
        /*
                goto eexit_2;
 
        /*


@@ -831,11 +856,11 @@ static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd)
        struct epitem *epi, *epir = NULL;
        struct epoll_filefd ffd;
 
        struct epitem *epi, *epir = NULL;
        struct epoll_filefd ffd;
 

-       EP_SET_FFD(&ffd, file, fd);
+       ep_set_ffd(&ffd, file, fd);

        read_lock_irqsave(&ep->lock, flags);
        for (rbp = ep->rbr.rb_node; rbp; ) {
                epi = rb_entry(rbp, struct epitem, rbn);
        read_lock_irqsave(&ep->lock, flags);
        for (rbp = ep->rbr.rb_node; rbp; ) {
                epi = rb_entry(rbp, struct epitem, rbn);

-               kcmp = EP_CMP_FFD(&ffd, &epi->ffd);
+               kcmp = ep_cmp_ffd(&ffd, &epi->ffd);

                if (kcmp > 0)
                        rbp = rbp->rb_right;
                else if (kcmp < 0)
                if (kcmp > 0)
                        rbp = rbp->rb_right;
                else if (kcmp < 0)


@@ -875,7 +900,7 @@ static void ep_release_epitem(struct epitem *epi)
 {
 
        if (atomic_dec_and_test(&epi->usecnt))
 {
 
        if (atomic_dec_and_test(&epi->usecnt))

-               EPI_MEM_FREE(epi);
+               kmem_cache_free(epi_cache, epi);

 }
 
 
 }
 
 


@@ -886,10 +911,10 @@ static void ep_release_epitem(struct epitem *epi)
 static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
                                 poll_table *pt)
 {
 static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
                                 poll_table *pt)
 {

-       struct epitem *epi = EP_ITEM_FROM_EPQUEUE(pt);
+       struct epitem *epi = ep_item_from_epqueue(pt);

        struct eppoll_entry *pwq;
 
        struct eppoll_entry *pwq;
 

-       if (epi->nwait >= 0 && (pwq = PWQ_MEM_ALLOC())) {
+       if (epi->nwait >= 0 && (pwq = kmem_cache_alloc(pwq_cache, SLAB_KERNEL))) {

                init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);
                pwq->whead = whead;
                pwq->base = epi;
                init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);
                pwq->whead = whead;
                pwq->base = epi;


@@ -912,7 +937,7 @@ static void ep_rbtree_insert(struct eventpoll *ep, struct epitem *epi)
        while (*p) {
                parent = *p;
                epic = rb_entry(parent, struct epitem, rbn);
        while (*p) {
                parent = *p;
                epic = rb_entry(parent, struct epitem, rbn);

-               kcmp = EP_CMP_FFD(&epi->ffd, &epic->ffd);
+               kcmp = ep_cmp_ffd(&epi->ffd, &epic->ffd);

                if (kcmp > 0)
                        p = &parent->rb_right;
                else
                if (kcmp > 0)
                        p = &parent->rb_right;
                else


@@ -932,17 +957,17 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
        struct ep_pqueue epq;
 
        error = -ENOMEM;
        struct ep_pqueue epq;
 
        error = -ENOMEM;

-       if (!(epi = EPI_MEM_ALLOC()))
+       if (!(epi = kmem_cache_alloc(epi_cache, SLAB_KERNEL)))

                goto eexit_1;
 
        /* Item initialization follow here ... */
                goto eexit_1;
 
        /* Item initialization follow here ... */

-       EP_RB_INITNODE(&epi->rbn);
+       ep_rb_initnode(&epi->rbn);

        INIT_LIST_HEAD(&epi->rdllink);
        INIT_LIST_HEAD(&epi->fllink);
        INIT_LIST_HEAD(&epi->txlink);
        INIT_LIST_HEAD(&epi->pwqlist);
        epi->ep = ep;
        INIT_LIST_HEAD(&epi->rdllink);
        INIT_LIST_HEAD(&epi->fllink);
        INIT_LIST_HEAD(&epi->txlink);
        INIT_LIST_HEAD(&epi->pwqlist);
        epi->ep = ep;

-       EP_SET_FFD(&epi->ffd, tfile, fd);
+       ep_set_ffd(&epi->ffd, tfile, fd);

        epi->event = *event;
        atomic_set(&epi->usecnt, 1);
        epi->nwait = 0;
        epi->event = *event;
        atomic_set(&epi->usecnt, 1);
        epi->nwait = 0;


@@ -978,7 +1003,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
        ep_rbtree_insert(ep, epi);
 
        /* If the file is already "ready" we drop it inside the ready list */
        ep_rbtree_insert(ep, epi);
 
        /* If the file is already "ready" we drop it inside the ready list */

-       if ((revents & event->events) && !EP_IS_LINKED(&epi->rdllink)) {
+       if ((revents & event->events) && !ep_is_linked(&epi->rdllink)) {

                list_add_tail(&epi->rdllink, &ep->rdllist);
 
                /* Notify waiting tasks that events are available */
                list_add_tail(&epi->rdllink, &ep->rdllist);
 
                /* Notify waiting tasks that events are available */


@@ -1007,11 +1032,11 @@ eexit_2:
         * allocated wait queue.
         */
        write_lock_irqsave(&ep->lock, flags);
         * allocated wait queue.
         */
        write_lock_irqsave(&ep->lock, flags);

-       if (EP_IS_LINKED(&epi->rdllink))
-               EP_LIST_DEL(&epi->rdllink);
+       if (ep_is_linked(&epi->rdllink))
+               ep_list_del(&epi->rdllink);

        write_unlock_irqrestore(&ep->lock, flags);
 
        write_unlock_irqrestore(&ep->lock, flags);
 

-       EPI_MEM_FREE(epi);
+       kmem_cache_free(epi_cache, epi);

 eexit_1:
        return error;
 }
 eexit_1:
        return error;
 }


@@ -1050,14 +1075,14 @@ static int ep_modify(struct eventpoll *ep, struct epitem *epi, struct epoll_even
         * If the item is not linked to the hash it means that it's on its
         * way toward the removal. Do nothing in this case.
         */
         * If the item is not linked to the hash it means that it's on its
         * way toward the removal. Do nothing in this case.
         */

-       if (EP_RB_LINKED(&epi->rbn)) {
+       if (ep_rb_linked(&epi->rbn)) {

                /*
                 * If the item is "hot" and it is not registered inside the ready
                 * list, push it inside. If the item is not "hot" and it is currently
                 * registered inside the ready list, unlink it.
                 */
                if (revents & event->events) {
                /*
                 * If the item is "hot" and it is not registered inside the ready
                 * list, push it inside. If the item is not "hot" and it is currently
                 * registered inside the ready list, unlink it.
                 */
                if (revents & event->events) {

-                       if (!EP_IS_LINKED(&epi->rdllink)) {
+                       if (!ep_is_linked(&epi->rdllink)) {

                                list_add_tail(&epi->rdllink, &ep->rdllist);
 
                                /* Notify waiting tasks that events are available */
                                list_add_tail(&epi->rdllink, &ep->rdllist);
 
                                /* Notify waiting tasks that events are available */


@@ -1097,9 +1122,9 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
                while (!list_empty(lsthead)) {
                        pwq = list_entry(lsthead->next, struct eppoll_entry, llink);
 
                while (!list_empty(lsthead)) {
                        pwq = list_entry(lsthead->next, struct eppoll_entry, llink);
 

-                       EP_LIST_DEL(&pwq->llink);
+                       ep_list_del(&pwq->llink);

                        remove_wait_queue(pwq->whead, &pwq->wait);
                        remove_wait_queue(pwq->whead, &pwq->wait);

-                       PWQ_MEM_FREE(pwq);
+                       kmem_cache_free(pwq_cache, pwq);

                }
        }
 }
                }
        }
 }


@@ -1118,7 +1143,7 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi)
         * The check protect us from doing a double unlink ( crash ).
         */
        error = -ENOENT;
         * The check protect us from doing a double unlink ( crash ).
         */
        error = -ENOENT;

-       if (!EP_RB_LINKED(&epi->rbn))
+       if (!ep_rb_linked(&epi->rbn))

                goto eexit_1;
 
        /*
                goto eexit_1;
 
        /*


@@ -1133,14 +1158,14 @@ static int ep_unlink(struct eventpoll *ep, struct epitem *epi)
         * This operation togheter with the above check closes the door to
         * double unlinks.
         */
         * This operation togheter with the above check closes the door to
         * double unlinks.
         */

-       EP_RB_ERASE(&epi->rbn, &ep->rbr);
+       ep_rb_erase(&epi->rbn, &ep->rbr);

 
        /*
         * If the item we are going to remove is inside the ready file descriptors
         * we want to remove it from this list to avoid stale events.
         */
 
        /*
         * If the item we are going to remove is inside the ready file descriptors
         * we want to remove it from this list to avoid stale events.
         */

-       if (EP_IS_LINKED(&epi->rdllink))
-               EP_LIST_DEL(&epi->rdllink);
+       if (ep_is_linked(&epi->rdllink))
+               ep_list_del(&epi->rdllink);

 
        error = 0;
 eexit_1:
 
        error = 0;
 eexit_1:


@@ -1174,8 +1199,8 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi)
 
        /* Remove the current item from the list of epoll hooks */
        spin_lock(&file->f_ep_lock);
 
        /* Remove the current item from the list of epoll hooks */
        spin_lock(&file->f_ep_lock);

-       if (EP_IS_LINKED(&epi->fllink))
-               EP_LIST_DEL(&epi->fllink);
+       if (ep_is_linked(&epi->fllink))
+               ep_list_del(&epi->fllink);

        spin_unlock(&file->f_ep_lock);
 
        /* We need to acquire the write IRQ lock before calling ep_unlink() */
        spin_unlock(&file->f_ep_lock);
 
        /* We need to acquire the write IRQ lock before calling ep_unlink() */


@@ -1210,7 +1235,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
 {
        int pwake = 0;
        unsigned long flags;
 {
        int pwake = 0;
        unsigned long flags;

-       struct epitem *epi = EP_ITEM_FROM_WAIT(wait);
+       struct epitem *epi = ep_item_from_wait(wait);

        struct eventpoll *ep = epi->ep;
 
        DNPRINTK(3, (KERN_INFO "[%p] eventpoll: poll_callback(%p) epi=%p ep=%p\n",
        struct eventpoll *ep = epi->ep;
 
        DNPRINTK(3, (KERN_INFO "[%p] eventpoll: poll_callback(%p) epi=%p ep=%p\n",


@@ -1228,7 +1253,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
                goto is_disabled;
 
        /* If this file is already in the ready list we exit soon */
                goto is_disabled;
 
        /* If this file is already in the ready list we exit soon */

-       if (EP_IS_LINKED(&epi->rdllink))
+       if (ep_is_linked(&epi->rdllink))

                goto is_linked;
 
        list_add_tail(&epi->rdllink, &ep->rdllist);
                goto is_linked;
 
        list_add_tail(&epi->rdllink, &ep->rdllist);


@@ -1307,7 +1332,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist
                lnk = lnk->next;
 
                /* If this file is already in the ready list we exit soon */
                lnk = lnk->next;
 
                /* If this file is already in the ready list we exit soon */

-               if (!EP_IS_LINKED(&epi->txlink)) {
+               if (!ep_is_linked(&epi->txlink)) {

                        /*
                         * This is initialized in this way so that the default
                         * behaviour of the reinjecting code will be to push back
                        /*
                         * This is initialized in this way so that the default
                         * behaviour of the reinjecting code will be to push back


@@ -1322,7 +1347,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist
                        /*
                         * Unlink the item from the ready list.
                         */
                        /*
                         * Unlink the item from the ready list.
                         */

-                       EP_LIST_DEL(&epi->rdllink);
+                       ep_list_del(&epi->rdllink);

                }
        }
 
                }
        }
 


@@ -1401,7 +1426,7 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist)
                epi = list_entry(txlist->next, struct epitem, txlink);
 
                /* Unlink the current item from the transfer list */
                epi = list_entry(txlist->next, struct epitem, txlink);
 
                /* Unlink the current item from the transfer list */

-               EP_LIST_DEL(&epi->txlink);
+               ep_list_del(&epi->txlink);

 
                /*
                 * If the item is no more linked to the interest set, we don't
 
                /*
                 * If the item is no more linked to the interest set, we don't


@@ -1410,8 +1435,8 @@ static void ep_reinject_items(struct eventpoll *ep, struct list_head *txlist)
                 * item is set to have an Edge Triggered behaviour, we don't have
                 * to push it back either.
                 */
                 * item is set to have an Edge Triggered behaviour, we don't have
                 * to push it back either.
                 */

-               if (EP_RB_LINKED(&epi->rbn) && !(epi->event.events & EPOLLET) &&
-                   (epi->revents & epi->event.events) && !EP_IS_LINKED(&epi->rdllink)) {
+               if (ep_rb_linked(&epi->rbn) && !(epi->event.events & EPOLLET) &&
+                   (epi->revents & epi->event.events) && !ep_is_linked(&epi->rdllink)) {

                        list_add_tail(&epi->rdllink, &ep->rdllist);
                        ricnt++;
                }
                        list_add_tail(&epi->rdllink, &ep->rdllist);
                        ricnt++;
                }