From b030a4dd609e167da7f73c2d1fa5af864a0aea17 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Thu, 23 Jun 2005 00:10:03 -0700 Subject: [PATCH] [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 Acked-by: Davide Libenzi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/eventpoll.c | 195 ++++++++++++++++++++++++++++--------------------- 1 file changed, 110 insertions(+), 85 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 9900e333655a..6ab1dd0ca904 100644 --- 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 -/* 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; @@ -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) { @@ -456,7 +481,7 @@ void eventpoll_release_file(struct file *file) 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); @@ -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; - if (EP_OP_HASH_EVENT(op) && + if (ep_op_hash_event(op) && 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; - if (file == tfile || !IS_FILE_EPOLL(file)) + if (file == tfile || !is_file_epoll(file)) 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; - if (!IS_FILE_EPOLL(file)) + if (!is_file_epoll(file)) 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; - 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); - 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) @@ -875,7 +900,7 @@ static void ep_release_epitem(struct epitem *epi) { 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) { - struct epitem *epi = EP_ITEM_FROM_EPQUEUE(pt); + struct epitem *epi = ep_item_from_epqueue(pt); 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; @@ -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); - kcmp = EP_CMP_FFD(&epi->ffd, &epic->ffd); + kcmp = ep_cmp_ffd(&epi->ffd, &epic->ffd); 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; - if (!(epi = EPI_MEM_ALLOC())) + if (!(epi = kmem_cache_alloc(epi_cache, SLAB_KERNEL))) 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; - 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; @@ -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 */ - 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 */ @@ -1007,11 +1032,11 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, * 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); - EPI_MEM_FREE(epi); + kmem_cache_free(epi_cache, epi); 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 (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 (!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 */ @@ -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); - EP_LIST_DEL(&pwq->llink); + ep_list_del(&pwq->llink); 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; - if (!EP_RB_LINKED(&epi->rbn)) + if (!ep_rb_linked(&epi->rbn)) 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. */ - 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 (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: @@ -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); - 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() */ @@ -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; - 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", @@ -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 */ - if (EP_IS_LINKED(&epi->rdllink)) + if (ep_is_linked(&epi->rdllink)) 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 */ - 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 @@ -1322,7 +1347,7 @@ static int ep_collect_ready_items(struct eventpoll *ep, struct list_head *txlist /* * 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 */ - EP_LIST_DEL(&epi->txlink); + ep_list_del(&epi->txlink); /* * 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. */ - 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++; }