diff options
| -rw-r--r-- | drivers/char/Makefile | 4 | ||||
| -rw-r--r-- | drivers/char/eventpoll.c | 1438 | ||||
| -rw-r--r-- | fs/Makefile | 5 | ||||
| -rw-r--r-- | fs/eventpoll.c | 1293 | ||||
| -rw-r--r-- | fs/fcblist.c | 146 | ||||
| -rw-r--r-- | fs/file_table.c | 6 | ||||
| -rw-r--r-- | fs/pipe.c | 36 | ||||
| -rw-r--r-- | fs/select.c | 8 | ||||
| -rw-r--r-- | include/linux/eventpoll.h | 34 | ||||
| -rw-r--r-- | include/linux/fcblist.h | 71 | ||||
| -rw-r--r-- | include/linux/fs.h | 4 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 4 | ||||
| -rw-r--r-- | include/linux/poll.h | 18 | ||||
| -rw-r--r-- | include/net/sock.h | 12 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
15 files changed, 1342 insertions, 1741 deletions
diff --git a/drivers/char/Makefile b/drivers/char/Makefile index bf21584d6d9d..7dfa2d4850b7 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -7,14 +7,14 @@ # FONTMAPFILE = cp437.uni -obj-y += mem.o tty_io.o n_tty.o tty_ioctl.o pty.o misc.o random.o eventpoll.o +obj-y += mem.o tty_io.o n_tty.o tty_ioctl.o pty.o misc.o random.o # All of the (potential) objects that export symbols. # This list comes from 'grep -l EXPORT_SYMBOL *.[hc]'. export-objs := busmouse.o vt.o generic_serial.o ip2main.o \ ite_gpio.o keyboard.o misc.o nvram.o random.o rtc.o \ - selection.o sonypi.o sysrq.o tty_io.o tty_ioctl.o eventpoll.o + selection.o sonypi.o sysrq.o tty_io.o tty_ioctl.o obj-$(CONFIG_VT) += vt_ioctl.o vc_screen.o consolemap.o consolemap_deftbl.o selection.o keyboard.o obj-$(CONFIG_HW_CONSOLE) += vt.o defkeymap.o diff --git a/drivers/char/eventpoll.c b/drivers/char/eventpoll.c deleted file mode 100644 index 57f2b40019c4..000000000000 --- a/drivers/char/eventpoll.c +++ /dev/null @@ -1,1438 +0,0 @@ -/* - * drivers/char/eventpoll.c ( Efficent event polling implementation ) - * Copyright (C) 2001,...,2002 Davide Libenzi - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * Davide Libenzi <davidel@xmailserver.org> - * - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/fs.h> -#include <linux/file.h> -#include <linux/signal.h> -#include <linux/errno.h> -#include <linux/mm.h> -#include <linux/vmalloc.h> -#include <linux/slab.h> -#include <linux/poll.h> -#include <linux/miscdevice.h> -#include <linux/random.h> -#include <linux/smp_lock.h> -#include <linux/wrapper.h> -#include <linux/string.h> -#include <linux/list.h> -#include <linux/spinlock.h> -#include <linux/wait.h> -#include <linux/fcblist.h> -#include <linux/rwsem.h> -#include <asm/bitops.h> -#include <asm/uaccess.h> -#include <asm/system.h> -#include <asm/io.h> -#include <asm/mman.h> -#include <asm/atomic.h> -#include <linux/eventpoll.h> - - - -#define EVENTPOLLFS_MAGIC 0x03111965 /* My birthday should work for this :) */ - -#define DEBUG_EPOLL 0 - -#if DEBUG_EPOLL > 0 -#define DPRINTK(x) printk x -#define DNPRINTK(n, x) do { if ((n) <= DEBUG_EPOLL) printk x; } while (0) -#else /* #if DEBUG_EPOLL > 0 */ -#define DPRINTK(x) (void) 0 -#define DNPRINTK(n, x) (void) 0 -#endif /* #if DEBUG_EPOLL > 0 */ - -#define DEBUG_DPI 0 - -#if DEBUG_DPI != 0 -#define DPI_SLAB_DEBUG (SLAB_DEBUG_FREE | SLAB_RED_ZONE /* | SLAB_POISON */) -#else /* #if DEBUG_DPI != 0 */ -#define DPI_SLAB_DEBUG 0 -#endif /* #if DEBUG_DPI != 0 */ - -#define INITIAL_HASH_BITS 7 -#define MAX_HASH_BITS 18 -#define RESIZE_LENGTH 2 - -#define DPI_MEM_ALLOC() (struct epitem *) kmem_cache_alloc(dpi_cache, SLAB_KERNEL) -#define DPI_MEM_FREE(p) kmem_cache_free(dpi_cache, p) -#define IS_FILE_EPOLL(f) ((f)->f_op == &eventpoll_fops) - - -/* - * Type used for versioning events snapshots inside the double buffer. - */ -typedef unsigned long long event_version_t; - -/* - * This structure is stored inside the "private_data" member of the file - * structure and rapresent the main data sructure for the eventpoll - * interface. - */ -struct eventpoll { - /* - * Protect the evenpoll interface from sys_epoll_ctl(2), ioctl(EP_POLL) - * and ->write() concurrency. It basically serialize the add/remove/edit - * of items in the interest set. - */ - struct rw_semaphore acsem; - - /* - * Protect the this structure access. When the "acsem" is acquired - * togheter with this one, "acsem" should be acquired first. Or, - * "lock" nests inside "acsem". - */ - rwlock_t lock; - - /* Wait queue used by sys_epoll_wait() and ioctl(EP_POLL) */ - wait_queue_head_t wq; - - /* Wait queue used by file->poll() */ - wait_queue_head_t poll_wait; - - /* This is the hash used to store the "struct epitem" elements */ - struct list_head *hash; - - unsigned int hbits; - unsigned int hmask; - atomic_t hents; - atomic_t resize; - - /* Number of pages currently allocated in each side of the double buffer */ - int numpages; - - /* - * Current page set pointer, switched from "pages0" and "pages1" each time - * ep_poll() returns events to the caller. - */ - char **pages; - - /* Each one of these contains the pages allocated for each side of - * the double buffer. - */ - char *pages0[MAX_EVENTPOLL_PAGES]; - char *pages1[MAX_EVENTPOLL_PAGES]; - - /* - * Variable containing the vma base address where the double buffer - * pages are mapped onto. - */ - unsigned long vmabase; - - /* - * Certain functions cannot be called if the double buffer pages are - * not allocated and if the memory mapping is not in place. This tells - * us that everything is setup to fully use the interface. - */ - atomic_t mmapped; - - /* Number of events currently available inside the current snapshot */ - int eventcnt; - - /* - * Variable storing the current "version" of the snapshot. It is used - * to validate the validity of the current slot pointed by the "index" - * member of a "struct epitem". - */ - event_version_t ver; -}; - -/* - * Each file descriptor added to the eventpoll interface will - * have an entry of this type linked to the hash. - */ -struct epitem { - /* List header used to link this structure to the eventpoll hash */ - struct list_head llink; - - /* The "container" of this item */ - struct eventpoll *ep; - - /* The file this item refers to */ - struct file *file; - - /* The structure that describe the interested events and the source fd */ - struct pollfd pfd; - - /* - * The index inside the current double buffer that stores the active - * event slot for this item ( file ). - */ - int index; - - /* - * The version that is used to validate if the current slot is still - * valid or if it refers to an old snapshot. It is matches togheter - * with the one inside the eventpoll structure. - */ - event_version_t ver; -}; - - - - -static int ep_getfd(int *efd, struct inode **einode, struct file **efile); -static int ep_alloc_pages(char **pages, int numpages); -static int ep_free_pages(char **pages, int numpages); -static int ep_init(struct eventpoll *ep); -static void ep_free(struct eventpoll *ep); -static struct epitem *ep_find_nl(struct eventpoll *ep, int fd); -static struct epitem *ep_find(struct eventpoll *ep, int fd); -static int ep_hashresize(struct eventpoll *ep, unsigned long *kflags); -static int ep_insert(struct eventpoll *ep, struct pollfd *pfd); -static int ep_remove(struct eventpoll *ep, struct epitem *dpi); -static void notify_proc(struct file *file, void *data, unsigned long *local, - long *event); -static int open_eventpoll(struct inode *inode, struct file *file); -static int close_eventpoll(struct inode *inode, struct file *file); -static unsigned int poll_eventpoll(struct file *file, poll_table *wait); -static int write_eventpoll(struct file *file, const char *buffer, size_t count, - loff_t *ppos); -static int ep_poll(struct eventpoll *ep, struct evpoll *dvp); -static int ep_do_alloc_pages(struct eventpoll *ep, int numpages); -static int ioctl_eventpoll(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg); -static void eventpoll_mm_open(struct vm_area_struct * vma); -static void eventpoll_mm_close(struct vm_area_struct * vma); -static int mmap_eventpoll(struct file *file, struct vm_area_struct *vma); -static int eventpollfs_delete_dentry(struct dentry *dentry); -static struct inode *get_eventpoll_inode(void); -static struct super_block *eventpollfs_get_sb(struct file_system_type *fs_type, - int flags, char *dev_name, void *data); - - - -/* Slab cache used to allocate "struct epitem" */ -static kmem_cache_t *dpi_cache; - -/* Virtual fs used to allocate inodes for eventpoll files */ -static struct vfsmount *eventpoll_mnt; - -/* File callbacks that implement the eventpoll file behaviour */ -static struct file_operations eventpoll_fops = { - .write = write_eventpoll, - .ioctl = ioctl_eventpoll, - .mmap = mmap_eventpoll, - .open = open_eventpoll, - .release = close_eventpoll, - .poll = poll_eventpoll -}; - -/* Memory mapping callbacks for the eventpoll file */ -static struct vm_operations_struct eventpoll_mmap_ops = { - .open = eventpoll_mm_open, - .close = eventpoll_mm_close, -}; - -/* - * The "struct miscdevice" is used to register the eventpoll device - * to make it suitable to be openend from a /dev file. - */ -static struct miscdevice eventpoll_miscdev = { - EVENTPOLL_MINOR, "eventpoll", &eventpoll_fops -}; - -/* - * This is used to register the virtual file system from where - * eventpoll inodes are allocated. - */ -static struct file_system_type eventpoll_fs_type = { - .name = "eventpollfs", - .get_sb = eventpollfs_get_sb, - .kill_sb = kill_anon_super, -}; - -/* Very basic directory entry operations for the eventpoll virtual file system */ -static struct dentry_operations eventpollfs_dentry_operations = { - .d_delete = eventpollfs_delete_dentry, -}; - - - -/* - * It opens an eventpoll file descriptor by allocating space for "maxfds" - * file descriptors. It is the kernel part of the userspace epoll_create(2). - */ -asmlinkage int sys_epoll_create(int maxfds) -{ - int error = -EINVAL, fd; - unsigned long addr; - struct inode *inode; - struct file *file; - struct eventpoll *ep; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d)\n", - current, maxfds)); - - /* - * It is not possible to store more than MAX_FDS_IN_EVENTPOLL file - * descriptors inside the eventpoll interface. - */ - if (maxfds > MAX_FDS_IN_EVENTPOLL) - goto eexit_1; - - /* - * Creates all the items needed to setup an eventpoll file. That is, - * a file structure, and inode and a free file descriptor. - */ - error = ep_getfd(&fd, &inode, &file); - if (error) - goto eexit_1; - - /* - * Calls the code to initialize the eventpoll file. This code is - * the same as the "open" file operation callback because inside - * ep_getfd() we did what the kernel usually does before invoking - * corresponding file "open" callback. - */ - error = open_eventpoll(inode, file); - if (error) - goto eexit_2; - - /* The "private_data" member is setup by open_eventpoll() */ - ep = file->private_data; - - /* Alloc pages for the event double buffer */ - error = ep_do_alloc_pages(ep, EP_FDS_PAGES(maxfds + 1)); - if (error) - goto eexit_2; - - /* - * Create a user space mapping of the event double buffer to - * avoid kernel to user space memory copy when returning events - * to the caller. - */ - down_write(¤t->mm->mmap_sem); - addr = do_mmap_pgoff(file, 0, EP_MAP_SIZE(maxfds + 1), PROT_READ, - MAP_PRIVATE, 0); - up_write(¤t->mm->mmap_sem); - error = PTR_ERR((void *) addr); - if (IS_ERR((void *) addr)) - goto eexit_2; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n", - current, maxfds, fd)); - - return fd; - -eexit_2: - sys_close(fd); -eexit_1: - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n", - current, maxfds, error)); - return error; -} - - -/* - * The following function implement the controller interface for the eventpoll - * file that enable the insertion/removal/change of file descriptors inside - * the interest set. It rapresents the kernel part of the user spcae epoll_ctl(2). - */ -asmlinkage int sys_epoll_ctl(int epfd, int op, int fd, unsigned int events) -{ - int error = -EBADF; - struct file *file; - struct eventpoll *ep; - struct epitem *dpi; - struct pollfd pfd; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_ctl(%d, %d, %d, %u)\n", - current, epfd, op, fd, events)); - - file = fget(epfd); - if (!file) - goto eexit_1; - - /* - * We have to check that the file structure underneath the file descriptor - * the user passed to us _is_ an eventpoll file. - */ - error = -EINVAL; - if (!IS_FILE_EPOLL(file)) - goto eexit_2; - - /* - * At this point it is safe to assume that the "private_data" contains - * our own data structure. - */ - ep = file->private_data; - - down_write(&ep->acsem); - - pfd.fd = fd; - pfd.events = events | POLLERR | POLLHUP; - pfd.revents = 0; - - dpi = ep_find(ep, fd); - - error = -EINVAL; - switch (op) { - case EP_CTL_ADD: - if (!dpi) - error = ep_insert(ep, &pfd); - else - error = -EEXIST; - break; - case EP_CTL_DEL: - if (dpi) - error = ep_remove(ep, dpi); - else - error = -ENOENT; - break; - case EP_CTL_MOD: - if (dpi) { - dpi->pfd.events = events; - error = 0; - } else - error = -ENOENT; - break; - } - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_ctl(%d, %d, %d, %u) = %d\n", - current, epfd, op, fd, events, error)); - - up_write(&ep->acsem); - -eexit_2: - fput(file); -eexit_1: - return error; -} - - -/* - * Implement the event wait interface for the eventpoll file. It is the kernel - * part of the user space epoll_wait(2). - */ -asmlinkage int sys_epoll_wait(int epfd, struct pollfd const **events, int timeout) -{ - int error = -EBADF; - void *eaddr; - struct file *file; - struct eventpoll *ep; - struct evpoll dvp; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_wait(%d, %p, %d)\n", - current, epfd, events, timeout)); - - file = fget(epfd); - if (!file) - goto eexit_1; - - /* - * We have to check that the file structure underneath the file descriptor - * the user passed to us _is_ an eventpoll file. - */ - error = -EINVAL; - if (!IS_FILE_EPOLL(file)) - goto eexit_2; - - /* - * At this point it is safe to assume that the "private_data" contains - * our own data structure. - */ - ep = file->private_data; - - /* - * It is possible that the user created an eventpoll file by open()ing - * the corresponding /dev/ file and he did not perform the correct - * initialization required by the old /dev/epoll interface. This test - * protect us from this scenario. - */ - error = -EINVAL; - if (!atomic_read(&ep->mmapped)) - goto eexit_2; - - dvp.ep_timeout = timeout; - error = ep_poll(ep, &dvp); - if (error > 0) { - eaddr = (void *) (ep->vmabase + dvp.ep_resoff); - if (copy_to_user(events, &eaddr, sizeof(struct pollfd *))) - error = -EFAULT; - } - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_wait(%d, %p, %d) = %d\n", - current, epfd, events, timeout, error)); - -eexit_2: - fput(file); -eexit_1: - return error; -} - - -/* - * Creates the file descriptor to be used by the epoll interface. - */ -static int ep_getfd(int *efd, struct inode **einode, struct file **efile) -{ - struct qstr this; - char name[32]; - struct dentry *dentry; - struct inode *inode; - struct file *file; - int error, fd; - - /* Get an ready to use file */ - error = -ENFILE; - file = get_empty_filp(); - if (!file) - goto eexit_1; - - /* Allocates an inode from the eventpoll file system */ - inode = get_eventpoll_inode(); - error = PTR_ERR(inode); - if (IS_ERR(inode)) - goto eexit_2; - - /* Allocates a free descriptor to plug the file onto */ - error = get_unused_fd(); - if (error < 0) - goto eexit_3; - fd = error; - - /* - * Link the inode to a directory entry by creating a unique name - * using the inode number. - */ - error = -ENOMEM; - sprintf(name, "[%lu]", inode->i_ino); - this.name = name; - this.len = strlen(name); - this.hash = inode->i_ino; - dentry = d_alloc(eventpoll_mnt->mnt_sb->s_root, &this); - if (!dentry) - goto eexit_4; - dentry->d_op = &eventpollfs_dentry_operations; - d_add(dentry, inode); - file->f_vfsmnt = mntget(eventpoll_mnt); - file->f_dentry = dget(dentry); - - /* - * Initialize the file as read/write because it could be used - * with write() to add/remove/change interest sets. - */ - file->f_pos = 0; - file->f_flags = O_RDWR; - file->f_op = &eventpoll_fops; - file->f_mode = FMODE_READ | FMODE_WRITE; - file->f_version = 0; - file->private_data = NULL; - - /* Install the new setup file into the allocated fd. */ - fd_install(fd, file); - - *efd = fd; - *einode = inode; - *efile = file; - return 0; - -eexit_4: - put_unused_fd(fd); -eexit_3: - iput(inode); -eexit_2: - put_filp(file); -eexit_1: - return error; -} - - -static int ep_alloc_pages(char **pages, int numpages) -{ - int ii; - - for (ii = 0; ii < numpages; ii++) { - pages[ii] = (char *) __get_free_pages(GFP_KERNEL, 0); - if (!pages[ii]) { - for (--ii; ii >= 0; ii--) { - ClearPageReserved(virt_to_page(pages[ii])); - free_pages((unsigned long) pages[ii], 0); - } - return -ENOMEM; - } - SetPageReserved(virt_to_page(pages[ii])); - } - return 0; -} - - -static int ep_free_pages(char **pages, int numpages) -{ - int ii; - - for (ii = 0; ii < numpages; ii++) { - ClearPageReserved(virt_to_page(pages[ii])); - free_pages((unsigned long) pages[ii], 0); - } - return 0; -} - - -static int ep_init(struct eventpoll *ep) -{ - int ii, hentries; - - init_rwsem(&ep->acsem); - rwlock_init(&ep->lock); - init_waitqueue_head(&ep->wq); - init_waitqueue_head(&ep->poll_wait); - ep->hbits = INITIAL_HASH_BITS; - ep->hmask = (1 << ep->hbits) - 1; - atomic_set(&ep->hents, 0); - atomic_set(&ep->resize, 0); - atomic_set(&ep->mmapped, 0); - ep->numpages = 0; - ep->vmabase = 0; - ep->pages = ep->pages0; - ep->eventcnt = 0; - ep->ver = 1; - - hentries = ep->hmask + 1; - if (!(ep->hash = (struct list_head *) vmalloc(hentries * sizeof(struct list_head)))) - return -ENOMEM; - - for (ii = 0; ii < hentries; ii++) - INIT_LIST_HEAD(&ep->hash[ii]); - - return 0; -} - - -static void ep_free(struct eventpoll *ep) -{ - int ii; - struct list_head *lsthead; - - /* - * Walks through the whole hash by unregistering file callbacks and - * freeing each "struct epitem". - */ - for (ii = 0; ii <= ep->hmask; ii++) { - lsthead = &ep->hash[ii]; - while (!list_empty(lsthead)) { - struct epitem *dpi = list_entry(lsthead->next, struct epitem, llink); - - file_notify_delcb(dpi->file, notify_proc); - list_del(lsthead->next); - DPI_MEM_FREE(dpi); - } - } - /* - * At this point we can free the hash and the pages used for the event - * double buffer. The ep_free() function is called from the "close" - * file operations callback, and this garanties us that the pages are - * already unmapped. - */ - vfree(ep->hash); - if (ep->numpages > 0) { - ep_free_pages(ep->pages0, ep->numpages); - ep_free_pages(ep->pages1, ep->numpages); - } -} - - -/* - * No lock version of ep_find(), used when the code had to acquire the lock - * before calling the function. - */ -static struct epitem *ep_find_nl(struct eventpoll *ep, int fd) -{ - struct epitem *dpi = NULL; - struct list_head *lsthead, *lnk; - - lsthead = &ep->hash[fd & ep->hmask]; - list_for_each(lnk, lsthead) { - dpi = list_entry(lnk, struct epitem, llink); - - if (dpi->pfd.fd == fd) break; - dpi = NULL; - } - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_find(%d) -> %p\n", - current, fd, dpi)); - - return dpi; -} - - -static struct epitem *ep_find(struct eventpoll *ep, int fd) -{ - struct epitem *dpi; - unsigned long flags; - - read_lock_irqsave(&ep->lock, flags); - - dpi = ep_find_nl(ep, fd); - - read_unlock_irqrestore(&ep->lock, flags); - - return dpi; -} - - -static int ep_hashresize(struct eventpoll *ep, unsigned long *kflags) -{ - struct list_head *hash, *oldhash; - unsigned int hbits = ep->hbits + 1; - unsigned int hmask = (1 << hbits) - 1; - int ii, res, hentries = hmask + 1; - unsigned long flags = *kflags; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_hashresize(%p) bits=%u\n", - current, ep, hbits)); - - write_unlock_irqrestore(&ep->lock, flags); - - res = -ENOMEM; - if (!(hash = (struct list_head *) vmalloc(hentries * sizeof(struct list_head)))) { - write_lock_irqsave(&ep->lock, flags); - goto eexit_1; - } - - for (ii = 0; ii < hentries; ii++) - INIT_LIST_HEAD(&hash[ii]); - - write_lock_irqsave(&ep->lock, flags); - - oldhash = ep->hash; - for (ii = 0; ii <= ep->hmask; ii++) { - struct list_head *oldhead = &oldhash[ii], *lnk; - - while (!list_empty(oldhead)) { - struct epitem *dpi = list_entry(lnk = oldhead->next, struct epitem, llink); - - list_del(lnk); - list_add(lnk, &hash[dpi->pfd.fd & hmask]); - } - } - - ep->hash = hash; - ep->hbits = hbits; - ep->hmask = hmask; - - write_unlock_irqrestore(&ep->lock, flags); - vfree(oldhash); - write_lock_irqsave(&ep->lock, flags); - - res = 0; -eexit_1: - *kflags = flags; - atomic_dec(&ep->resize); - return res; -} - - -static int ep_insert(struct eventpoll *ep, struct pollfd *pfd) -{ - int error; - struct epitem *dpi; - struct file *file; - unsigned long flags; - - if (atomic_read(&ep->hents) >= (ep->numpages * POLLFD_X_PAGE)) - return -E2BIG; - - file = fget(pfd->fd); - if (!file) - return -EBADF; - - error = -ENOMEM; - if (!(dpi = DPI_MEM_ALLOC())) - goto eexit_1; - - INIT_LIST_HEAD(&dpi->llink); - dpi->ep = ep; - dpi->file = file; - dpi->pfd = *pfd; - dpi->index = -1; - dpi->ver = ep->ver - 1; - - write_lock_irqsave(&ep->lock, flags); - - list_add(&dpi->llink, &ep->hash[pfd->fd & ep->hmask]); - atomic_inc(&ep->hents); - - if (!atomic_read(&ep->resize) && - (atomic_read(&ep->hents) >> ep->hbits) > RESIZE_LENGTH && - ep->hbits < MAX_HASH_BITS) { - atomic_inc(&ep->resize); - ep_hashresize(ep, &flags); - } - - write_unlock_irqrestore(&ep->lock, flags); - - file_notify_addcb(file, notify_proc, dpi); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_insert(%p, %d)\n", - current, ep, pfd->fd)); - - error = 0; -eexit_1: - fput(file); - - return error; -} - - -/* - * Removes a "struct epitem" from the eventpoll hash and deallocates - * all the associated resources. - */ -static int ep_remove(struct eventpoll *ep, struct epitem *dpi) -{ - unsigned long flags; - struct pollfd *pfd, *lpfd; - struct epitem *ldpi; - - /* First, removes the callback from the file callback list */ - file_notify_delcb(dpi->file, notify_proc); - - write_lock_irqsave(&ep->lock, flags); - - list_del(&dpi->llink); - atomic_dec(&ep->hents); - - /* - * This is to remove stale events. We don't want that the removed file - * has a pending event that might be associated with a file inserted - * at a later time inside the eventpoll interface. this code checks - * if the currently removed file has a valid pending event and, if it does, - * manages things to remove it and decrement the currently available - * event count. - */ - if (dpi->index >= 0 && dpi->ver == ep->ver && dpi->index < ep->eventcnt) { - pfd = (struct pollfd *) (ep->pages[EVENT_PAGE_INDEX(dpi->index)] + - EVENT_PAGE_OFFSET(dpi->index)); - if (pfd->fd == dpi->pfd.fd && dpi->index < --ep->eventcnt) { - lpfd = (struct pollfd *) (ep->pages[EVENT_PAGE_INDEX(ep->eventcnt)] + - EVENT_PAGE_OFFSET(ep->eventcnt)); - *pfd = *lpfd; - - if ((ldpi = ep_find_nl(ep, pfd->fd))) ldpi->index = dpi->index; - } - } - - write_unlock_irqrestore(&ep->lock, flags); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_remove(%p, %d)\n", - current, ep, dpi->pfd.fd)); - - /* At this point it is safe to free the eventpoll item */ - DPI_MEM_FREE(dpi); - - return 0; -} - - -/* - * This is the event notify callback that is called from fs/fcblist.c because - * of the registration ( file_notify_addcb() ) done in ep_insert(). - */ -static void notify_proc(struct file *file, void *data, unsigned long *local, - long *event) -{ - struct epitem *dpi = data; - struct eventpoll *ep = dpi->ep; - struct pollfd *pfd; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: notify(%p, %p, %ld, %ld) ep=%p\n", - current, file, data, event[0], event[1], ep)); - - /* - * We don't need to disable IRQs here because the callback dispatch - * routine inside fs/fcblist.c already call us with disabled IRQ. - */ - write_lock(&ep->lock); - - /* We're not expecting any of those events. Jump out soon ... */ - if (!(dpi->pfd.events & event[1])) - goto out; - - /* - * This logic determins if an active even slot is available for the - * currently signaled file, or if we have to make space for a new one - * and increment the number of ready file descriptors ( ep->eventcnt ). - */ - if (dpi->index < 0 || dpi->ver != ep->ver) { - if (ep->eventcnt >= (ep->numpages * POLLFD_X_PAGE)) - goto out; - dpi->index = ep->eventcnt++; - dpi->ver = ep->ver; - pfd = (struct pollfd *) (ep->pages[EVENT_PAGE_INDEX(dpi->index)] + - EVENT_PAGE_OFFSET(dpi->index)); - *pfd = dpi->pfd; - } else { - pfd = (struct pollfd *) (ep->pages[EVENT_PAGE_INDEX(dpi->index)] + - EVENT_PAGE_OFFSET(dpi->index)); - if (pfd->fd != dpi->pfd.fd) { - if (ep->eventcnt >= (ep->numpages * POLLFD_X_PAGE)) - goto out; - dpi->index = ep->eventcnt++; - pfd = (struct pollfd *) (ep->pages[EVENT_PAGE_INDEX(dpi->index)] + - EVENT_PAGE_OFFSET(dpi->index)); - *pfd = dpi->pfd; - } - } - - /* - * Merge event bits into the corresponding event slot inside the - * double buffer. - */ - pfd->revents |= (pfd->events & event[1]); - - /* - * Wake up ( if active ) both the eventpoll wait list and the ->poll() - * wait list. - */ - if (waitqueue_active(&ep->wq)) - wake_up(&ep->wq); - if (waitqueue_active(&ep->poll_wait)) - wake_up(&ep->poll_wait); -out: - write_unlock(&ep->lock); -} - - -static int open_eventpoll(struct inode *inode, struct file *file) -{ - int res; - struct eventpoll *ep; - - if (!(ep = kmalloc(sizeof(struct eventpoll), GFP_KERNEL))) - return -ENOMEM; - - memset(ep, 0, sizeof(*ep)); - if ((res = ep_init(ep))) { - kfree(ep); - return res; - } - - file->private_data = ep; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: open() ep=%p\n", current, ep)); - return 0; -} - - -static int close_eventpoll(struct inode *inode, struct file *file) -{ - struct eventpoll *ep = file->private_data; - - if (ep) { - ep_free(ep); - kfree(ep); - } - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: close() ep=%p\n", current, ep)); - return 0; -} - - -static unsigned int poll_eventpoll(struct file *file, poll_table *wait) -{ - struct eventpoll *ep = file->private_data; - - poll_wait(file, &ep->poll_wait, wait); - if (ep->eventcnt) - return POLLIN | POLLRDNORM; - - return 0; -} - - -static int write_eventpoll(struct file *file, const char *buffer, size_t count, - loff_t *ppos) -{ - int rcount; - struct eventpoll *ep = file->private_data; - struct epitem *dpi; - struct pollfd pfd; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: write(%p, %d)\n", current, ep, count)); - - /* The size of the write must be a multiple of sizeof(struct pollfd) */ - rcount = -EINVAL; - if (count % sizeof(struct pollfd)) - goto eexit_1; - - /* - * And we have also to verify that that area is correctly accessible - * for the user. - */ - if ((rcount = verify_area(VERIFY_READ, buffer, count))) - goto eexit_1; - - down_write(&ep->acsem); - - rcount = 0; - - while (count > 0) { - if (__copy_from_user(&pfd, buffer, sizeof(pfd))) { - rcount = -EFAULT; - goto eexit_2; - } - - dpi = ep_find(ep, pfd.fd); - - if (pfd.fd >= current->files->max_fds || !current->files->fd[pfd.fd]) - pfd.events = POLLREMOVE; - if (pfd.events & POLLREMOVE) { - if (dpi) { - ep_remove(ep, dpi); - rcount += sizeof(pfd); - } - } - else if (dpi) { - dpi->pfd.events = pfd.events; - rcount += sizeof(pfd); - } else { - pfd.revents = 0; - if (!ep_insert(ep, &pfd)) - rcount += sizeof(pfd); - } - - buffer += sizeof(pfd); - count -= sizeof(pfd); - } - -eexit_2: - up_write(&ep->acsem); -eexit_1: - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: write(%p, %d) = %d\n", - current, ep, count, rcount)); - - return rcount; -} - - -static int ep_poll(struct eventpoll *ep, struct evpoll *dvp) -{ - int res = 0; - long timeout; - unsigned long flags; - wait_queue_t wait; - - /* - * We don't want ep_poll() to be called if the correct sequence - * of operations are performed to initialize it. This won't happen - * for the system call interface but it could happen using the - * old /dev/epoll interface, that is maintained for compatibility. - */ - if (!atomic_read(&ep->mmapped)) - return -EINVAL; - - write_lock_irqsave(&ep->lock, flags); - - res = 0; - if (!ep->eventcnt) { - /* - * We don't have any available event to return to the caller. - * We need to sleep here, and we will be wake up by - * notify_proc() when events will become available. - */ - init_waitqueue_entry(&wait, current); - add_wait_queue(&ep->wq, &wait); - - /* - * Calculate the timeout by checking for the "infinite" value ( -1 ) - * and the overflow condition ( > MAX_SCHEDULE_TIMEOUT / HZ ). The - * passed timeout is in milliseconds, that why (t * HZ) / 1000. - */ - timeout = dvp->ep_timeout == -1 || dvp->ep_timeout > MAX_SCHEDULE_TIMEOUT / HZ ? - MAX_SCHEDULE_TIMEOUT: (dvp->ep_timeout * HZ) / 1000; - - for (;;) { - /* - * We don't want to sleep if the notify_proc() sends us - * a wakeup in between. That's why we set the task state - * to TASK_INTERRUPTIBLE before doing the checks. - */ - set_current_state(TASK_INTERRUPTIBLE); - if (ep->eventcnt || !timeout) - break; - if (signal_pending(current)) { - res = -EINTR; - break; - } - - write_unlock_irqrestore(&ep->lock, flags); - timeout = schedule_timeout(timeout); - write_lock_irqsave(&ep->lock, flags); - } - remove_wait_queue(&ep->wq, &wait); - - set_current_state(TASK_RUNNING); - } - - /* - * If we've been wake up because of events became available, we need to: - * - * 1) null the number of available ready file descriptors - * 2) increment the version of the current ( next ) snapshot - * 3) swap the double buffer to return the current one to the caller - * 4) set the current ( for the user, previous for the interface ) offset - */ - if (!res && ep->eventcnt) { - res = ep->eventcnt; - ep->eventcnt = 0; - ++ep->ver; - if (ep->pages == ep->pages0) { - ep->pages = ep->pages1; - dvp->ep_resoff = 0; - } else { - ep->pages = ep->pages0; - dvp->ep_resoff = ep->numpages * PAGE_SIZE; - } - } - - write_unlock_irqrestore(&ep->lock, flags); - - return res; -} - - -static int ep_do_alloc_pages(struct eventpoll *ep, int numpages) -{ - int res, pgalloc, pgcpy; - unsigned long flags; - char **pages, **pages0, **pages1; - - if (atomic_read(&ep->mmapped)) - return -EBUSY; - if (numpages > MAX_EVENTPOLL_PAGES) - return -EINVAL; - - pgalloc = numpages - ep->numpages; - if ((pages = (char **) vmalloc(2 * (pgalloc + 1) * sizeof(char *))) == NULL) - return -ENOMEM; - pages0 = &pages[0]; - pages1 = &pages[pgalloc + 1]; - - if ((res = ep_alloc_pages(pages0, pgalloc))) - goto eexit_1; - - if ((res = ep_alloc_pages(pages1, pgalloc))) { - ep_free_pages(pages0, pgalloc); - goto eexit_1; - } - - write_lock_irqsave(&ep->lock, flags); - pgcpy = (ep->numpages + pgalloc) > numpages ? numpages - ep->numpages: pgalloc; - if (pgcpy > 0) { - memcpy(&ep->pages0[ep->numpages], pages0, pgcpy * sizeof(char *)); - memcpy(&ep->pages1[ep->numpages], pages1, pgcpy * sizeof(char *)); - ep->numpages += pgcpy; - } - write_unlock_irqrestore(&ep->lock, flags); - - if (pgcpy < pgalloc) { - if (pgcpy < 0) - pgcpy = 0; - ep_free_pages(&pages0[pgcpy], pgalloc - pgcpy); - ep_free_pages(&pages1[pgcpy], pgalloc - pgcpy); - } - -eexit_1: - vfree(pages); - return res; -} - - -static int ioctl_eventpoll(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - int res; - struct eventpoll *ep = file->private_data; - struct epitem *dpi; - unsigned long flags; - struct pollfd pfd; - struct evpoll dvp; - - switch (cmd) { - case EP_ALLOC: - res = ep_do_alloc_pages(ep, EP_FDS_PAGES(arg)); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ioctl(%p, EP_ALLOC, %lu) == %d\n", - current, ep, arg, res)); - return res; - - case EP_FREE: - if (atomic_read(&ep->mmapped)) - return -EBUSY; - - res = -EINVAL; - write_lock_irqsave(&ep->lock, flags); - if (ep->numpages > 0) { - ep_free_pages(ep->pages0, ep->numpages); - ep_free_pages(ep->pages1, ep->numpages); - ep->numpages = 0; - ep->pages = ep->pages0; - res = 0; - } - write_unlock_irqrestore(&ep->lock, flags); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ioctl(%p, EP_FREE) == %d\n", - current, ep, res)); - return res; - - case EP_POLL: - if (copy_from_user(&dvp, (void *) arg, sizeof(struct evpoll))) - return -EFAULT; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ioctl(%p, EP_POLL, %d)\n", - current, ep, dvp.ep_timeout)); - - res = ep_poll(ep, &dvp); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ioctl(%p, EP_POLL, %d) == %d\n", - current, ep, dvp.ep_timeout, res)); - - if (res > 0 && copy_to_user((void *) arg, &dvp, sizeof(struct evpoll))) - res = -EFAULT; - - return res; - - case EP_ISPOLLED: - if (copy_from_user(&pfd, (void *) arg, sizeof(struct pollfd))) - return 0; - - read_lock_irqsave(&ep->lock, flags); - - res = 0; - if (!(dpi = ep_find_nl(ep, pfd.fd))) - goto is_not_polled; - - pfd = dpi->pfd; - res = 1; - - is_not_polled: - read_unlock_irqrestore(&ep->lock, flags); - - if (res) - copy_to_user((void *) arg, &pfd, sizeof(struct pollfd)); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ioctl(%p, EP_ISPOLLED, %d) == %d\n", - current, ep, pfd.fd, res)); - return res; - } - - return -EINVAL; -} - - -static void eventpoll_mm_open(struct vm_area_struct * vma) -{ - struct file *file = vma->vm_file; - struct eventpoll *ep = file->private_data; - - if (ep) atomic_inc(&ep->mmapped); - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: mm_open(%p)\n", current, ep)); -} - - -static void eventpoll_mm_close(struct vm_area_struct * vma) -{ - struct file *file = vma->vm_file; - struct eventpoll *ep = file->private_data; - - if (ep && atomic_dec_and_test(&ep->mmapped)) - ep->vmabase = 0; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: mm_close(%p)\n", current, ep)); -} - - -static int mmap_eventpoll(struct file *file, struct vm_area_struct *vma) -{ - struct eventpoll *ep = file->private_data; - unsigned long start; - int ii, res, numpages; - size_t mapsize; - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: mmap(%p, %lx, %lx)\n", - current, ep, vma->vm_start, vma->vm_pgoff << PAGE_SHIFT)); - - /* - * We need the eventpoll file to be RW but we don't want it to be - * mapped RW. This test perform the test and reject RW mmaping. - */ - if (vma->vm_flags & VM_WRITE) - return -EACCES; - - if ((vma->vm_pgoff << PAGE_SHIFT) != 0) - return -EINVAL; - - /* - * We need to verify that the mapped area covers all the allocated - * double buffer. - */ - mapsize = PAGE_ALIGN(vma->vm_end - vma->vm_start); - numpages = mapsize >> PAGE_SHIFT; - - res = -EINVAL; - if (numpages != (2 * ep->numpages)) - goto eexit_1; - - /* - * Map the double buffer starting from "vma->vm_start" up to - * "vma->vm_start + ep->numpages * PAGE_SIZE". - */ - start = vma->vm_start; - for (ii = 0; ii < ep->numpages; ii++) { - if ((res = remap_page_range(vma, start, __pa(ep->pages0[ii]), - PAGE_SIZE, vma->vm_page_prot))) - goto eexit_1; - start += PAGE_SIZE; - } - for (ii = 0; ii < ep->numpages; ii++) { - if ((res = remap_page_range(vma, start, __pa(ep->pages1[ii]), - PAGE_SIZE, vma->vm_page_prot))) - goto eexit_1; - start += PAGE_SIZE; - } - vma->vm_ops = &eventpoll_mmap_ops; - - /* Saves the base mapping address for later use in sys_epoll_wait(2) */ - ep->vmabase = vma->vm_start; - - /* - * Ok, mapping has been done. We can open the door to functions that - * requires the mapping to be in place. - */ - atomic_set(&ep->mmapped, 1); - - res = 0; -eexit_1: - - DNPRINTK(3, (KERN_INFO "[%p] eventpoll: mmap(%p, %lx, %lx) == %d\n", - current, ep, vma->vm_start, vma->vm_pgoff << PAGE_SHIFT, res)); - return res; -} - - -static int eventpollfs_delete_dentry(struct dentry *dentry) -{ - - return 1; -} - - -static struct inode *get_eventpoll_inode(void) -{ - int error = -ENOMEM; - struct inode *inode = new_inode(eventpoll_mnt->mnt_sb); - - if (!inode) - goto eexit_1; - - inode->i_fop = &eventpoll_fops; - - /* - * Mark the inode dirty from the very beginning, - * that way it will never be moved to the dirty - * list because "mark_inode_dirty()" will think - * that it already _is_ on the dirty list. - */ - inode->i_state = I_DIRTY; - inode->i_mode = S_IRUSR | S_IWUSR; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; - inode->i_blksize = PAGE_SIZE; - return inode; - -eexit_1: - return ERR_PTR(error); -} - - -static struct super_block *eventpollfs_get_sb(struct file_system_type *fs_type, - int flags, char *dev_name, void *data) -{ - - return get_sb_pseudo(fs_type, "eventpoll:", NULL, EVENTPOLLFS_MAGIC); -} - - -static int __init eventpoll_init(void) -{ - int error; - - /* Allocates slab cache used to allocate "struct epitem" items */ - error = -ENOMEM; - dpi_cache = kmem_cache_create("eventpoll", - sizeof(struct epitem), - __alignof__(struct epitem), - DPI_SLAB_DEBUG, NULL, NULL); - if (!dpi_cache) - goto eexit_1; - - /* - * Register the virtual file system that will be the source of inodes - * for the eventpoll files - */ - error = register_filesystem(&eventpoll_fs_type); - if (error) - goto eexit_2; - - /* Mount the above commented virtual file system */ - eventpoll_mnt = kern_mount(&eventpoll_fs_type); - error = PTR_ERR(eventpoll_mnt); - if (IS_ERR(eventpoll_mnt)) - goto eexit_3; - - /* - * This is to maintain compatibility with the old /dev/epoll interface. - * We need to register a misc device so that the caller can open(2) it - * through a file inside /dev. - */ - error = misc_register(&eventpoll_miscdev); - if (error) - goto eexit_4; - - printk(KERN_INFO "[%p] eventpoll: driver installed.\n", current); - - return error; - -eexit_4: - mntput(eventpoll_mnt); -eexit_3: - unregister_filesystem(&eventpoll_fs_type); -eexit_2: - kmem_cache_destroy(dpi_cache); -eexit_1: - - return error; -} - - -static void __exit eventpoll_exit(void) -{ - /* Undo all operations done inside eventpoll_init() */ - unregister_filesystem(&eventpoll_fs_type); - mntput(eventpoll_mnt); - misc_deregister(&eventpoll_miscdev); - kmem_cache_destroy(dpi_cache); -} - -module_init(eventpoll_init); -module_exit(eventpoll_exit); - -MODULE_LICENSE("GPL"); - diff --git a/fs/Makefile b/fs/Makefile index 42700ab2e563..cb865dc62657 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -6,15 +6,14 @@ # export-objs := open.o dcache.o buffer.o bio.o inode.o dquot.o mpage.o aio.o \ - fcntl.o read_write.o dcookies.o fcblist.o mbcache.o \ - posix_acl.o xattr_acl.o + fcntl.o read_write.o dcookies.o mbcache.o posix_acl.o xattr_acl.o obj-y := open.o read_write.o devices.o file_table.o buffer.o \ bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \ namei.o fcntl.o ioctl.o readdir.o select.o fifo.o locks.o \ dcache.o inode.o attr.o bad_inode.o file.o dnotify.o \ filesystems.o namespace.o seq_file.o xattr.o libfs.o \ - fs-writeback.o mpage.o direct-io.o aio.o fcblist.o + fs-writeback.o mpage.o direct-io.o aio.o eventpoll.o ifneq ($(CONFIG_NFSD),n) ifneq ($(CONFIG_NFSD),) diff --git a/fs/eventpoll.c b/fs/eventpoll.c new file mode 100644 index 000000000000..1fb5e57401a8 --- /dev/null +++ b/fs/eventpoll.c @@ -0,0 +1,1293 @@ +/* + * drivers/char/eventpoll.c ( Efficent event polling implementation ) + * Copyright (C) 2001,...,2002 Davide Libenzi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * Davide Libenzi <davidel@xmailserver.org> + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/poll.h> +#include <linux/smp_lock.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/wait.h> +#include <asm/bitops.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/io.h> +#include <asm/mman.h> +#include <asm/atomic.h> +#include <linux/eventpoll.h> + + + +#define EVENTPOLLFS_MAGIC 0x03111965 /* My birthday should work for this :) */ + +#define DEBUG_EPOLL 0 + +#if DEBUG_EPOLL > 0 +#define DPRINTK(x) printk x +#define DNPRINTK(n, x) do { if ((n) <= DEBUG_EPOLL) printk x; } while (0) +#else /* #if DEBUG_EPOLL > 0 */ +#define DPRINTK(x) (void) 0 +#define DNPRINTK(n, x) (void) 0 +#endif /* #if DEBUG_EPOLL > 0 */ + +#define DEBUG_DPI 0 + +#if DEBUG_DPI != 0 +#define DPI_SLAB_DEBUG (SLAB_DEBUG_FREE | SLAB_RED_ZONE /* | SLAB_POISON */) +#else /* #if DEBUG_DPI != 0 */ +#define DPI_SLAB_DEBUG 0 +#endif /* #if DEBUG_DPI != 0 */ + + +/* Maximum storage for the eventpoll interest set */ +#define EP_MAX_FDS_SIZE (1024 * 128) + +/* We don't want the hash to be smaller than this */ +#define EP_MIN_HASH_SIZE 101 +/* + * Event buffer dimension used to cache events before sending them in + * userspace with a __copy_to_user(). The event buffer is in stack, + * so keep this size fairly small. + */ +#define EP_EVENT_BUFF_SIZE 32 + +/* Maximum number of wait queue we can attach to */ +#define EP_MAX_POLL_QUEUE 2 + +/* Number of hash entries ( "struct list_head" ) inside a page */ +#define EP_HENTRY_X_PAGE (PAGE_SIZE / sizeof(struct list_head)) + +/* Maximum size of the hash in pages */ +#define EP_MAX_HPAGES (EP_MAX_FDS_SIZE / EP_HENTRY_X_PAGE + 1) + +/* Macro to allocate a "struct epitem" from the slab cache */ +#define DPI_MEM_ALLOC() (struct epitem *) kmem_cache_alloc(dpi_cache, SLAB_KERNEL) + +/* Macro to free a "struct epitem" to the slab cache */ +#define DPI_MEM_FREE(p) kmem_cache_free(dpi_cache, p) + +/* Fast test to see if the file is an evenpoll file */ +#define IS_FILE_EPOLL(f) ((f)->f_op == &eventpoll_fops) + +/* + * Remove the item from the list and perform its initialization. + * This is usefull 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) + + + + + +/* + * This structure is stored inside the "private_data" member of the file + * structure and rapresent the main data sructure for the eventpoll + * interface. + */ +struct eventpoll { + /* Used to link to the "struct eventpoll" list ( eplist ) */ + struct list_head llink; + + /* Protect the this structure access */ + rwlock_t lock; + + /* Wait queue used by sys_epoll_wait() */ + wait_queue_head_t wq; + + /* Wait queue used by file->poll() */ + wait_queue_head_t poll_wait; + + /* List of ready file descriptors */ + struct list_head rdllist; + + /* Size of the hash */ + int hsize; + + /* Number of pages currently allocated for the hash */ + int nhpages; + + /* Pages for the "struct epitem" hash */ + char *hpages[EP_MAX_HPAGES]; +}; + +/* Wait structure used by the poll hooks */ +struct eppoll_entry { + /* The "base" pointer is set to the container "struct epitem" */ + void *base; + + /* + * Wait queue item that will be linked to the target file wait + * queue head. + */ + wait_queue_t wait; + + /* The wait queue head that linked the "wait" wait queue item */ + wait_queue_head_t *whead; +}; + +/* + * Each file descriptor added to the eventpoll interface will + * have an entry of this type linked to the hash. + */ +struct epitem { + /* List header used to link this structure to the eventpoll hash */ + struct list_head llink; + + /* List header used to link this structure to the eventpoll ready list */ + struct list_head rdllink; + + /* Number of active wait queue attached to poll operations */ + int nwait; + + /* Wait queue used to attach poll operations */ + struct eppoll_entry wait[EP_MAX_POLL_QUEUE]; + + /* The "container" of this item */ + struct eventpoll *ep; + + /* The file this item refers to */ + struct file *file; + + /* The structure that describe the interested events and the source fd */ + struct pollfd pfd; + + /* + * Used to keep track of the usage count of the structure. This avoids + * that the structure will desappear from underneath our processing. + */ + atomic_t usecnt; +}; + + + + +static int ep_is_prime(int n); +static int ep_getfd(int *efd, struct inode **einode, struct file **efile); +static int ep_alloc_pages(char **pages, int numpages); +static int ep_free_pages(char **pages, int numpages); +static int ep_file_init(struct file *file, int hsize); +static int ep_hash_index(struct eventpoll *ep, struct file *file); +static struct list_head *ep_hash_entry(struct eventpoll *ep, int index); +static int ep_init(struct eventpoll *ep, int hsize); +static void ep_free(struct eventpoll *ep); +static struct epitem *ep_find(struct eventpoll *ep, struct file *file); +static void ep_use_epitem(struct epitem *dpi); +static void ep_release_epitem(struct epitem *dpi); +static void ep_ptable_queue_proc(void *priv, wait_queue_head_t *whead); +static int ep_insert(struct eventpoll *ep, struct pollfd *pfd, struct file *tfile); +static unsigned int ep_get_file_events(struct file *file); +static int ep_modify(struct eventpoll *ep, struct epitem *dpi, unsigned int events); +static int ep_unlink(struct eventpoll *ep, struct epitem *dpi); +static int ep_remove(struct eventpoll *ep, struct epitem *dpi); +static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync); +static int ep_eventpoll_close(struct inode *inode, struct file *file); +static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait); +static int ep_events_transfer(struct eventpoll *ep, struct pollfd *events, int maxevents); +static int ep_poll(struct eventpoll *ep, struct pollfd *events, int maxevents, + int timeout); +static int eventpollfs_delete_dentry(struct dentry *dentry); +static struct inode *ep_eventpoll_inode(void); +static struct super_block *eventpollfs_get_sb(struct file_system_type *fs_type, + int flags, char *dev_name, void *data); + + +/* Use to link togheter all the "struct eventpoll" */ +static struct list_head eplist; + +/* Serialize the access to "eplist" */ +static rwlock_t eplock; + +/* Slab cache used to allocate "struct epitem" */ +static kmem_cache_t *dpi_cache; + +/* Virtual fs used to allocate inodes for eventpoll files */ +static struct vfsmount *eventpoll_mnt; + +/* File callbacks that implement the eventpoll file behaviour */ +static struct file_operations eventpoll_fops = { + .release = ep_eventpoll_close, + .poll = ep_eventpoll_poll +}; + +/* + * This is used to register the virtual file system from where + * eventpoll inodes are allocated. + */ +static struct file_system_type eventpoll_fs_type = { + .name = "eventpollfs", + .get_sb = eventpollfs_get_sb, + .kill_sb = kill_anon_super, +}; + +/* Very basic directory entry operations for the eventpoll virtual file system */ +static struct dentry_operations eventpollfs_dentry_operations = { + .d_delete = eventpollfs_delete_dentry, +}; + + + +/* Report if the number is prime. Needed to correctly size the hash */ +static int ep_is_prime(int n) +{ + + if (n > 3) { + if (n & 1) { + int i, hn = n / 2; + + for (i = 3; i < hn; i += 2) + if (!(n % i)) + return 0; + } else + return 0; + } + return 1; +} + + +/* + * This is called from inside fs/file_table.c:__fput() to unlink files + * from the eventpoll interface. We need to have this facility to cleanup + * correctly files that are closed without being removed from the eventpoll + * interface. + */ +void ep_notify_file_close(struct file *file) +{ + unsigned long flags; + struct list_head *lnk; + struct eventpoll *ep; + struct epitem *dpi; + + read_lock_irqsave(&eplock, flags); + list_for_each(lnk, &eplist) { + ep = list_entry(lnk, struct eventpoll, llink); + + while ((dpi = ep_find(ep, file))) { + ep_remove(ep, dpi); + ep_release_epitem(dpi); + } + } + read_unlock_irqrestore(&eplock, flags); +} + + +/* + * It opens an eventpoll file descriptor by suggesting a storage of "size" + * file descriptors. It is the kernel part of the userspace epoll_create(2). + */ +asmlinkage int sys_epoll_create(int size) +{ + int error, fd; + struct inode *inode; + struct file *file; + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d)\n", + current, size)); + + /* Search the nearest prime number higher than "size" */ + for (; !ep_is_prime(size); size++); + if (size < EP_MIN_HASH_SIZE) + size = EP_MIN_HASH_SIZE; + + /* + * Creates all the items needed to setup an eventpoll file. That is, + * a file structure, and inode and a free file descriptor. + */ + error = ep_getfd(&fd, &inode, &file); + if (error) + goto eexit_1; + + /* Setup the file internal data structure ( "struct eventpoll" ) */ + error = ep_file_init(file, size); + if (error) + goto eexit_2; + + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n", + current, size, fd)); + + return fd; + +eexit_2: + sys_close(fd); +eexit_1: + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n", + current, size, error)); + return error; +} + + +/* + * The following function implement the controller interface for the eventpoll + * file that enable the insertion/removal/change of file descriptors inside + * the interest set. It rapresents the kernel part of the user spcae epoll_ctl(2). + */ +asmlinkage int sys_epoll_ctl(int epfd, int op, int fd, unsigned int events) +{ + int error; + struct file *file, *tfile; + struct eventpoll *ep; + struct epitem *dpi; + struct pollfd pfd; + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_ctl(%d, %d, %d, %u)\n", + current, epfd, op, fd, events)); + + /* Get the "struct file *" for the eventpoll file */ + error = -EBADF; + file = fget(epfd); + if (!file) + goto eexit_1; + + /* Get the "struct file *" for the target file */ + tfile = fget(fd); + if (!tfile) + goto eexit_2; + + /* The target file descriptor must support poll */ + error = -EPERM; + if (!tfile->f_op || !tfile->f_op->poll) + goto eexit_3; + + /* + * We have to check that the file structure underneath the file descriptor + * the user passed to us _is_ an eventpoll file. + */ + error = -EINVAL; + if (!IS_FILE_EPOLL(file)) + goto eexit_3; + + /* + * At this point it is safe to assume that the "private_data" contains + * our own data structure. + */ + ep = file->private_data; + + /* + * Try to lookup the file inside our hash table. When an item is found + * ep_find() increases the usage count of the item so that it won't + * desappear underneath us. The only thing that might happen, if someone + * tries very hard, is a double insertion of the same file descriptor. + * This does not rapresent a problem though and we don't really want + * to put an extra syncronization object to deal with this harmless condition. + */ + dpi = ep_find(ep, tfile); + + error = -EINVAL; + switch (op) { + case EP_CTL_ADD: + if (!dpi) { + pfd.fd = fd; + pfd.events = events | POLLERR | POLLHUP; + pfd.revents = 0; + + error = ep_insert(ep, &pfd, tfile); + } else + error = -EEXIST; + break; + case EP_CTL_DEL: + if (dpi) + error = ep_remove(ep, dpi); + else + error = -ENOENT; + break; + case EP_CTL_MOD: + if (dpi) + error = ep_modify(ep, dpi, events | POLLERR | POLLHUP); + else + error = -ENOENT; + break; + } + + /* + * The function ep_find() increments the usage count of the structure + * so, if this is not NULL, we need to release it. + */ + if (dpi) + ep_release_epitem(dpi); + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_ctl(%d, %d, %d, %u) = %d\n", + current, epfd, op, fd, events, error)); + +eexit_3: + fput(tfile); +eexit_2: + fput(file); +eexit_1: + return error; +} + + +/* + * Implement the event wait interface for the eventpoll file. It is the kernel + * part of the user space epoll_wait(2). + */ +asmlinkage int sys_epoll_wait(int epfd, struct pollfd *events, int maxevents, + int timeout) +{ + int error; + struct file *file; + struct eventpoll *ep; + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_wait(%d, %p, %d, %d)\n", + current, epfd, events, maxevents, timeout)); + + /* Verify that the area passed by the user is writeable */ + if ((error = verify_area(VERIFY_WRITE, events, maxevents * sizeof(struct pollfd)))) + goto eexit_1; + + /* Get the "struct file *" for the eventpoll file */ + error = -EBADF; + file = fget(epfd); + if (!file) + goto eexit_1; + + /* + * We have to check that the file structure underneath the file descriptor + * the user passed to us _is_ an eventpoll file. + */ + error = -EINVAL; + if (!IS_FILE_EPOLL(file)) + goto eexit_2; + + /* + * At this point it is safe to assume that the "private_data" contains + * our own data structure. + */ + ep = file->private_data; + + /* Time to fish for events ... */ + error = ep_poll(ep, events, maxevents, timeout); + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_wait(%d, %p, %d, %d) = %d\n", + current, epfd, events, maxevents, timeout, error)); + +eexit_2: + fput(file); +eexit_1: + return error; +} + + +/* + * Creates the file descriptor to be used by the epoll interface. + */ +static int ep_getfd(int *efd, struct inode **einode, struct file **efile) +{ + struct qstr this; + char name[32]; + struct dentry *dentry; + struct inode *inode; + struct file *file; + int error, fd; + + /* Get an ready to use file */ + error = -ENFILE; + file = get_empty_filp(); + if (!file) + goto eexit_1; + + /* Allocates an inode from the eventpoll file system */ + inode = ep_eventpoll_inode(); + error = PTR_ERR(inode); + if (IS_ERR(inode)) + goto eexit_2; + + /* Allocates a free descriptor to plug the file onto */ + error = get_unused_fd(); + if (error < 0) + goto eexit_3; + fd = error; + + /* + * Link the inode to a directory entry by creating a unique name + * using the inode number. + */ + error = -ENOMEM; + sprintf(name, "[%lu]", inode->i_ino); + this.name = name; + this.len = strlen(name); + this.hash = inode->i_ino; + dentry = d_alloc(eventpoll_mnt->mnt_sb->s_root, &this); + if (!dentry) + goto eexit_4; + dentry->d_op = &eventpollfs_dentry_operations; + d_add(dentry, inode); + file->f_vfsmnt = mntget(eventpoll_mnt); + file->f_dentry = dget(dentry); + + /* + * Initialize the file as read/write because it could be used + * with write() to add/remove/change interest sets. + */ + file->f_pos = 0; + file->f_flags = O_RDONLY; + file->f_op = &eventpoll_fops; + file->f_mode = FMODE_READ; + file->f_version = 0; + file->private_data = NULL; + + /* Install the new setup file into the allocated fd. */ + fd_install(fd, file); + + *efd = fd; + *einode = inode; + *efile = file; + return 0; + +eexit_4: + put_unused_fd(fd); +eexit_3: + iput(inode); +eexit_2: + put_filp(file); +eexit_1: + return error; +} + + +static int ep_alloc_pages(char **pages, int numpages) +{ + int i; + + for (i = 0; i < numpages; i++) { + pages[i] = (char *) __get_free_pages(GFP_KERNEL, 0); + if (!pages[i]) { + for (--i; i >= 0; i--) { + ClearPageReserved(virt_to_page(pages[i])); + free_pages((unsigned long) pages[i], 0); + } + return -ENOMEM; + } + SetPageReserved(virt_to_page(pages[i])); + } + return 0; +} + + +static int ep_free_pages(char **pages, int numpages) +{ + int i; + + for (i = 0; i < numpages; i++) { + ClearPageReserved(virt_to_page(pages[i])); + free_pages((unsigned long) pages[i], 0); + } + return 0; +} + + +static int ep_file_init(struct file *file, int hsize) +{ + int error; + unsigned long flags; + struct eventpoll *ep; + + if (!(ep = kmalloc(sizeof(struct eventpoll), GFP_KERNEL))) + return -ENOMEM; + + memset(ep, 0, sizeof(*ep)); + + error = ep_init(ep, hsize); + if (error) { + kfree(ep); + return error; + } + + file->private_data = ep; + + /* Add the structure to the linked list that links "struct eventpoll" */ + write_lock_irqsave(&eplock, flags); + list_add(&ep->llink, &eplist); + write_unlock_irqrestore(&eplock, flags); + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_file_init() ep=%p\n", + current, ep)); + return 0; +} + + +/* + * Calculate the index of the hash relative to "file". + */ +static int ep_hash_index(struct eventpoll *ep, struct file *file) +{ + + return (int) ((((unsigned long) file) / sizeof(struct file)) % ep->hsize); +} + + +/* + * Returns the hash entry ( struct list_head * ) of the passed index. + */ +static struct list_head *ep_hash_entry(struct eventpoll *ep, int index) +{ + + return (struct list_head *) (ep->hpages[index / EP_HENTRY_X_PAGE] + + (index % EP_HENTRY_X_PAGE) * sizeof(struct list_head)); +} + + +static int ep_init(struct eventpoll *ep, int hsize) +{ + int error, i; + + INIT_LIST_HEAD(&ep->llink); + rwlock_init(&ep->lock); + init_waitqueue_head(&ep->wq); + init_waitqueue_head(&ep->poll_wait); + INIT_LIST_HEAD(&ep->rdllist); + + /* Hash allocation and setup */ + ep->hsize = hsize; + ep->nhpages = hsize / EP_HENTRY_X_PAGE + (hsize % EP_HENTRY_X_PAGE ? 1: 0); + error = ep_alloc_pages(ep->hpages, ep->nhpages); + if (error) + goto eexit_1; + + /* Initialize hash buckets */ + for (i = 0; i < ep->hsize; i++) + INIT_LIST_HEAD(ep_hash_entry(ep, i)); + + return 0; +eexit_1: + return error; +} + + +static void ep_free(struct eventpoll *ep) +{ + int i; + unsigned long flags; + struct list_head *lsthead; + + /* + * Walks through the whole hash by unregistering file callbacks and + * freeing each "struct epitem". + */ + for (i = 0; i < ep->hsize; i++) { + lsthead = ep_hash_entry(ep, i); + + /* + * We need to lock this because we could be hit by + * ep_notify_file_close() while we're freeing this. + */ + write_lock_irqsave(&ep->lock, flags); + + while (!list_empty(lsthead)) { + struct epitem *dpi = list_entry(lsthead->next, struct epitem, llink); + + /* The function ep_unlink() must be called with held lock */ + ep_unlink(ep, dpi); + + /* We release the lock before releasing the "struct epitem" */ + write_unlock_irqrestore(&ep->lock, flags); + + ep_release_epitem(dpi); + + /* And then we reaquire the lock ... */ + write_lock_irqsave(&ep->lock, flags); + } + + write_unlock_irqrestore(&ep->lock, flags); + } + + /* Remove the structure to the linked list that links "struct eventpoll" */ + write_lock_irqsave(&eplock, flags); + EP_LIST_DEL(&ep->llink); + write_unlock_irqrestore(&eplock, flags); + + /* Free hash pages */ + if (ep->nhpages > 0) + ep_free_pages(ep->hpages, ep->nhpages); +} + + +/* + * Search the file inside the eventpoll hash. It add usage count to + * the returned item, so the caller must call ep_release_epitem() + * after finished using the "struct epitem". + */ +static struct epitem *ep_find(struct eventpoll *ep, struct file *file) +{ + unsigned long flags; + struct list_head *lsthead, *lnk; + struct epitem *dpi = NULL; + + read_lock_irqsave(&ep->lock, flags); + + lsthead = ep_hash_entry(ep, ep_hash_index(ep, file)); + list_for_each(lnk, lsthead) { + dpi = list_entry(lnk, struct epitem, llink); + + if (dpi->file == file) { + ep_use_epitem(dpi); + break; + } + dpi = NULL; + } + + read_unlock_irqrestore(&ep->lock, flags); + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_find(%p) -> %p\n", + current, file, dpi)); + + return dpi; +} + + +/* + * Increment the usage count of the "struct epitem" making it sure + * that the user will have a valid pointer to reference. + */ +static void ep_use_epitem(struct epitem *dpi) +{ + + atomic_inc(&dpi->usecnt); +} + + +/* + * Decrement ( release ) the usage count by signaling that the user + * has finished using the structure. It might lead to freeing the + * structure itself if the count goes to zero. + */ +static void ep_release_epitem(struct epitem *dpi) +{ + + if (atomic_dec_and_test(&dpi->usecnt)) + DPI_MEM_FREE(dpi); +} + + +/* + * This is the callback that is used to add our wait queue to the + * target file wakeup lists. + */ +static void ep_ptable_queue_proc(void *priv, wait_queue_head_t *whead) +{ + struct epitem *dpi = priv; + + /* No more than EP_MAX_POLL_QUEUE wait queue are supported */ + if (dpi->nwait < EP_MAX_POLL_QUEUE) { + add_wait_queue(whead, &dpi->wait[dpi->nwait].wait); + dpi->wait[dpi->nwait].whead = whead; + dpi->nwait++; + } +} + + +static int ep_insert(struct eventpoll *ep, struct pollfd *pfd, struct file *tfile) +{ + int error, i, revents; + unsigned long flags; + struct epitem *dpi; + poll_table pt; + + error = -ENOMEM; + if (!(dpi = DPI_MEM_ALLOC())) + goto eexit_1; + + /* Item initialization follow here ... */ + INIT_LIST_HEAD(&dpi->llink); + INIT_LIST_HEAD(&dpi->rdllink); + dpi->ep = ep; + dpi->file = tfile; + dpi->pfd = *pfd; + atomic_set(&dpi->usecnt, 1); + dpi->nwait = 0; + for (i = 0; i < EP_MAX_POLL_QUEUE; i++) { + init_waitqueue_func_entry(&dpi->wait[i].wait, ep_poll_callback); + dpi->wait[i].whead = NULL; + dpi->wait[i].base = dpi; + } + + /* Attach the item to the poll hooks */ + poll_initwait_ex(&pt, 1, ep_ptable_queue_proc, dpi); + revents = tfile->f_op->poll(tfile, &pt); + poll_freewait(&pt); + + /* We have to drop the new item inside our item list to keep track of it */ + write_lock_irqsave(&ep->lock, flags); + + list_add(&dpi->llink, ep_hash_entry(ep, ep_hash_index(ep, tfile))); + + /* If the file is already "ready" we drop it inside the ready list */ + if ((revents & pfd->events) && !EP_IS_LINKED(&dpi->rdllink)) + list_add(&dpi->rdllink, &ep->rdllist); + + write_unlock_irqrestore(&ep->lock, flags); + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_insert(%p, %d)\n", + current, ep, pfd->fd)); + + return 0; + +eexit_1: + return error; +} + + +/* + * Returns the current events of the given file. It uses the special + * poll table initialization to avoid any poll queue insertion. + */ +static unsigned int ep_get_file_events(struct file *file) +{ + unsigned int revents; + poll_table pt; + + /* + * This is a special poll table initialization that will + * make poll_wait() to not perform any wait queue insertion when + * called by file->f_op->poll(). This is a fast way to retrieve + * file events with perform any queue insertion, hence saving CPU cycles. + */ + poll_initwait_ex(&pt, 0, NULL, NULL); + + revents = file->f_op->poll(file, &pt); + + poll_freewait(&pt); + return revents; +} + + +/* + * Modify the interest event mask by dropping an event if the new mask + * has a match in the current file status. + */ +static int ep_modify(struct eventpoll *ep, struct epitem *dpi, unsigned int events) +{ + unsigned int revents; + unsigned long flags; + + revents = ep_get_file_events(dpi->file); + + write_lock_irqsave(&ep->lock, flags); + + dpi->pfd.events = events; + + /* If the file is already "ready" we drop it inside the ready list */ + if ((revents & events) && EP_IS_LINKED(&dpi->llink) && !EP_IS_LINKED(&dpi->rdllink)) + list_add(&dpi->rdllink, &ep->rdllist); + + write_unlock_irqrestore(&ep->lock, flags); + + return 0; +} + + +/* + * Unlink the "struct epitem" from all places it might have been hooked up. + * This function must be called with write IRQ lock on "ep->lock". + */ +static int ep_unlink(struct eventpoll *ep, struct epitem *dpi) +{ + int i; + + /* + * It can happen that this one is called for an item already unlinked. + * The check protect us from doing a double unlink ( crash ). + */ + if (!EP_IS_LINKED(&dpi->llink)) + goto not_linked; + + /* + * At this point is safe to do the job, unlink the item from our list. + * This operation togheter with the above check closes the door to + * double unlinks. + */ + EP_LIST_DEL(&dpi->llink); + + /* Removes poll wait queue hooks */ + for (i = 0; i < dpi->nwait; i++) + remove_wait_queue(dpi->wait[i].whead, &dpi->wait[i].wait); + + /* + * 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(&dpi->rdllink)) + EP_LIST_DEL(&dpi->rdllink); + +not_linked: + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_unlink(%p, %d)\n", + current, ep, dpi->pfd.fd)); + + return 0; +} + + +/* + * Removes a "struct epitem" from the eventpoll hash and deallocates + * all the associated resources. + */ +static int ep_remove(struct eventpoll *ep, struct epitem *dpi) +{ + int error; + unsigned long flags; + + /* We need to acquire the write IRQ lock before calling ep_unlink() */ + write_lock_irqsave(&ep->lock, flags); + + /* Really unlink the item from the hash */ + error = ep_unlink(ep, dpi); + + write_unlock_irqrestore(&ep->lock, flags); + + if (error) + goto eexit_1; + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_remove(%p, %d)\n", + current, ep, dpi->pfd.fd)); + + /* At this point it is safe to free the eventpoll item */ + ep_release_epitem(dpi); + + error = 0; +eexit_1: + return error; +} + + +/* + * This is the callback that is passed to the wait queue wakeup + * machanism. It is called by the stored file descriptors when they + * have events to report. + */ +static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync) +{ + unsigned long flags; + struct epitem *dpi = EP_ITEM_FROM_WAIT(wait); + struct eventpoll *ep = dpi->ep; + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: poll_callback(%p) dpi=%p ep=%p\n", + current, dpi->file, dpi, ep)); + + write_lock_irqsave(&ep->lock, flags); + + /* If this file is already in the ready list we exit soon */ + if (EP_IS_LINKED(&dpi->rdllink)) + goto is_linked; + + list_add(&dpi->rdllink, &ep->rdllist); + +is_linked: + /* + * Wake up ( if active ) both the eventpoll wait list and the ->poll() + * wait list. + */ + if (waitqueue_active(&ep->wq)) + wake_up(&ep->wq); + if (waitqueue_active(&ep->poll_wait)) + wake_up(&ep->poll_wait); + + write_unlock_irqrestore(&ep->lock, flags); + return 1; +} + + +static int ep_eventpoll_close(struct inode *inode, struct file *file) +{ + struct eventpoll *ep = file->private_data; + + if (ep) { + ep_free(ep); + kfree(ep); + } + + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: close() ep=%p\n", current, ep)); + return 0; +} + + +static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait) +{ + unsigned int pollflags = 0; + unsigned long flags; + struct eventpoll *ep = file->private_data; + + /* Insert inside our poll wait queue */ + poll_wait(file, &ep->poll_wait, wait); + + /* Check our condition */ + read_lock_irqsave(&ep->lock, flags); + if (!list_empty(&ep->rdllist)) + pollflags = POLLIN | POLLRDNORM; + read_unlock_irqrestore(&ep->lock, flags); + + return pollflags; +} + + +/* + * Perform the transfer of events to user space. Optimize the copy by + * caching EP_EVENT_BUFF_SIZE events at a time and then copying it to user space. + */ +static int ep_events_transfer(struct eventpoll *ep, struct pollfd *events, int maxevents) +{ + int eventcnt, ebufcnt, revents; + unsigned long flags; + struct list_head *lsthead = &ep->rdllist; + struct pollfd eventbuf[EP_EVENT_BUFF_SIZE]; + poll_table pt; + + /* + * This is a special poll table initialization that will + * make poll_wait() to not perform any wait queue insertion when + * called by file->f_op->poll(). This is a fast way to retrieve + * file events with perform any queue insertion, hence saving CPU cycles. + */ + poll_initwait_ex(&pt, 0, NULL, NULL); + + write_lock_irqsave(&ep->lock, flags); + + for (eventcnt = 0, ebufcnt = 0; eventcnt < maxevents && !list_empty(lsthead);) { + struct epitem *dpi = list_entry(lsthead->next, struct epitem, rdllink); + + /* Remove the item from the ready list */ + EP_LIST_DEL(&dpi->rdllink); + + /* Fetch event bits from the signaled file */ + revents = dpi->file->f_op->poll(dpi->file, &pt); + + if (revents & dpi->pfd.events) { + eventbuf[ebufcnt] = dpi->pfd; + eventbuf[ebufcnt].revents = revents & eventbuf[ebufcnt].events; + ebufcnt++; + + /* If our buffer page is full we need to flush it to user space */ + if (ebufcnt == EP_EVENT_BUFF_SIZE) { + /* + * We need to drop the irqlock before using the function + * __copy_to_user() because it might fault. + */ + write_unlock_irqrestore(&ep->lock, flags); + if (__copy_to_user(&events[eventcnt], eventbuf, + ebufcnt * sizeof(struct pollfd))) { + poll_freewait(&pt); + return -EFAULT; + } + eventcnt += ebufcnt; + ebufcnt = 0; + write_lock_irqsave(&ep->lock, flags); + } + } + } + write_unlock_irqrestore(&ep->lock, flags); + + /* There might be still something inside our event buffer */ + if (ebufcnt) { + if (__copy_to_user(&events[eventcnt], eventbuf, + ebufcnt * sizeof(struct pollfd))) + eventcnt = -EFAULT; + else + eventcnt += ebufcnt; + } + + poll_freewait(&pt); + + return eventcnt; +} + + +static int ep_poll(struct eventpoll *ep, struct pollfd *events, int maxevents, + int timeout) +{ + int res = 0, eavail; + unsigned long flags; + long jtimeout; + wait_queue_t wait; + + /* + * Calculate the timeout by checking for the "infinite" value ( -1 ) + * and the overflow condition ( > MAX_SCHEDULE_TIMEOUT / HZ ). The + * passed timeout is in milliseconds, that why (t * HZ) / 1000. + */ + jtimeout = timeout == -1 || timeout > MAX_SCHEDULE_TIMEOUT / HZ ? + MAX_SCHEDULE_TIMEOUT: (timeout * HZ) / 1000; + +retry: + write_lock_irqsave(&ep->lock, flags); + + res = 0; + if (list_empty(&ep->rdllist)) { + /* + * We don't have any available event to return to the caller. + * We need to sleep here, and we will be wake up by + * ep_poll_callback() when events will become available. + */ + init_waitqueue_entry(&wait, current); + add_wait_queue(&ep->wq, &wait); + + for (;;) { + /* + * We don't want to sleep if the ep_poll_callback() sends us + * a wakeup in between. That's why we set the task state + * to TASK_INTERRUPTIBLE before doing the checks. + */ + set_current_state(TASK_INTERRUPTIBLE); + if (!list_empty(&ep->rdllist) || !jtimeout) + break; + if (signal_pending(current)) { + res = -EINTR; + break; + } + + write_unlock_irqrestore(&ep->lock, flags); + jtimeout = schedule_timeout(jtimeout); + write_lock_irqsave(&ep->lock, flags); + } + remove_wait_queue(&ep->wq, &wait); + + set_current_state(TASK_RUNNING); + } + + /* Is it worth to try to dig for events ? */ + eavail = !list_empty(&ep->rdllist); + + write_unlock_irqrestore(&ep->lock, flags); + + /* + * Try to transfer events to user space. In case we get 0 events and + * there's still timeout left over, we go trying again in search of + * more luck. + */ + if (!res && eavail && + !(res = ep_events_transfer(ep, events, maxevents)) && jtimeout) + goto retry; + + return res; +} + + +static int eventpollfs_delete_dentry(struct dentry *dentry) +{ + + return 1; +} + + +static struct inode *ep_eventpoll_inode(void) +{ + int error = -ENOMEM; + struct inode *inode = new_inode(eventpoll_mnt->mnt_sb); + + if (!inode) + goto eexit_1; + + inode->i_fop = &eventpoll_fops; + + /* + * Mark the inode dirty from the very beginning, + * that way it will never be moved to the dirty + * list because mark_inode_dirty() will think + * that it already _is_ on the dirty list. + */ + inode->i_state = I_DIRTY; + inode->i_mode = S_IRUSR | S_IWUSR; + inode->i_uid = current->fsuid; + inode->i_gid = current->fsgid; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + inode->i_blksize = PAGE_SIZE; + return inode; + +eexit_1: + return ERR_PTR(error); +} + + +static struct super_block *eventpollfs_get_sb(struct file_system_type *fs_type, + int flags, char *dev_name, void *data) +{ + + return get_sb_pseudo(fs_type, "eventpoll:", NULL, EVENTPOLLFS_MAGIC); +} + + +static int __init eventpoll_init(void) +{ + int error; + + /* Initialize the list that will link "struct eventpoll" */ + INIT_LIST_HEAD(&eplist); + + /* Initialize the rwlock used to access "eplist" */ + rwlock_init(&eplock); + + /* Allocates slab cache used to allocate "struct epitem" items */ + error = -ENOMEM; + dpi_cache = kmem_cache_create("eventpoll", + sizeof(struct epitem), + 0, + DPI_SLAB_DEBUG, NULL, NULL); + if (!dpi_cache) + goto eexit_1; + + /* + * Register the virtual file system that will be the source of inodes + * for the eventpoll files + */ + error = register_filesystem(&eventpoll_fs_type); + if (error) + goto eexit_2; + + /* Mount the above commented virtual file system */ + eventpoll_mnt = kern_mount(&eventpoll_fs_type); + error = PTR_ERR(eventpoll_mnt); + if (IS_ERR(eventpoll_mnt)) + goto eexit_3; + + printk(KERN_INFO "[%p] eventpoll: driver installed.\n", current); + + return 0; + +eexit_3: + unregister_filesystem(&eventpoll_fs_type); +eexit_2: + kmem_cache_destroy(dpi_cache); +eexit_1: + + return error; +} + + +static void __exit eventpoll_exit(void) +{ + /* Undo all operations done inside eventpoll_init() */ + unregister_filesystem(&eventpoll_fs_type); + mntput(eventpoll_mnt); + kmem_cache_destroy(dpi_cache); +} + +module_init(eventpoll_init); +module_exit(eventpoll_exit); + +MODULE_LICENSE("GPL"); + diff --git a/fs/fcblist.c b/fs/fcblist.c deleted file mode 100644 index d1e823b42ba8..000000000000 --- a/fs/fcblist.c +++ /dev/null @@ -1,146 +0,0 @@ -/* - * linux/fs/fcblist.c ( File event callbacks handling ) - * Copyright (C) 2001,...,2002 Davide Libenzi - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * Davide Libenzi <davidel@xmailserver.org> - * - */ - -#include <linux/config.h> -#include <linux/module.h> -#include <linux/fs.h> -#include <linux/mm.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/vmalloc.h> -#include <linux/poll.h> -#include <asm/bitops.h> -#include <linux/fcblist.h> - - -long ion_band_table[NSIGPOLL] = { - ION_IN, /* POLL_IN */ - ION_OUT, /* POLL_OUT */ - ION_IN, /* POLL_MSG */ - ION_ERR, /* POLL_ERR */ - 0, /* POLL_PRI */ - ION_HUP /* POLL_HUP */ -}; - -long poll_band_table[NSIGPOLL] = { - POLLIN | POLLRDNORM, /* POLL_IN */ - POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ - POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ - POLLERR, /* POLL_ERR */ - POLLPRI | POLLRDBAND, /* POLL_PRI */ - POLLHUP | POLLERR /* POLL_HUP */ -}; - - - -/* - * Walk through the file callback list by calling each registered callback - * with the event that happened on the "filep" file. Callbacks are called - * by holding a read lock on the callback list lock, and also by keeping - * local IRQs disabled. - */ -void file_notify_event(struct file *filep, long *event) -{ - unsigned long flags; - struct list_head *lnk, *lsthead; - - read_lock_irqsave(&filep->f_cblock, flags); - - lsthead = &filep->f_cblist; - list_for_each(lnk, lsthead) { - struct fcb_struct *fcbp = list_entry(lnk, struct fcb_struct, llink); - - fcbp->cbproc(filep, fcbp->data, fcbp->local, event); - } - - read_unlock_irqrestore(&filep->f_cblock, flags); -} - - -/* - * Add a new callback to the list of file callbacks. - */ -int file_notify_addcb(struct file *filep, - void (*cbproc)(struct file *, void *, unsigned long *, long *), - void *data) -{ - unsigned long flags; - struct fcb_struct *fcbp; - - if (!(fcbp = (struct fcb_struct *) kmalloc(sizeof(struct fcb_struct), GFP_KERNEL))) - return -ENOMEM; - - memset(fcbp, 0, sizeof(struct fcb_struct)); - fcbp->cbproc = cbproc; - fcbp->data = data; - - write_lock_irqsave(&filep->f_cblock, flags); - list_add_tail(&fcbp->llink, &filep->f_cblist); - write_unlock_irqrestore(&filep->f_cblock, flags); - - return 0; -} - - -/* - * Removes the callback "cbproc" from the file callback list. - */ -int file_notify_delcb(struct file *filep, - void (*cbproc)(struct file *, void *, unsigned long *, long *)) -{ - unsigned long flags; - struct list_head *lnk, *lsthead; - - write_lock_irqsave(&filep->f_cblock, flags); - - lsthead = &filep->f_cblist; - list_for_each(lnk, lsthead) { - struct fcb_struct *fcbp = list_entry(lnk, struct fcb_struct, llink); - - if (fcbp->cbproc == cbproc) { - list_del(lnk); - write_unlock_irqrestore(&filep->f_cblock, flags); - kfree(fcbp); - return 0; - } - } - - write_unlock_irqrestore(&filep->f_cblock, flags); - - return -ENOENT; -} - - -/* - * It is called at file cleanup time and removes all the registered callbacks. - */ -void file_notify_cleanup(struct file *filep) -{ - unsigned long flags; - struct list_head *lsthead; - - write_lock_irqsave(&filep->f_cblock, flags); - - lsthead = &filep->f_cblist; - while (!list_empty(lsthead)) { - struct fcb_struct *fcbp = list_entry(lsthead->next, struct fcb_struct, llink); - - list_del(lsthead->next); - write_unlock_irqrestore(&filep->f_cblock, flags); - kfree(fcbp); - write_lock_irqsave(&filep->f_cblock, flags); - } - - write_unlock_irqrestore(&filep->f_cblock, flags); -} - diff --git a/fs/file_table.c b/fs/file_table.c index 7a6285b72b4b..1195129262c2 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -8,12 +8,12 @@ #include <linux/string.h> #include <linux/slab.h> #include <linux/file.h> -#include <linux/fcblist.h> #include <linux/init.h> #include <linux/module.h> #include <linux/smp_lock.h> #include <linux/fs.h> #include <linux/security.h> +#include <linux/eventpoll.h> /* sysctl tunables... */ struct files_stat_struct files_stat = {0, 0, NR_FILE}; @@ -59,7 +59,6 @@ struct file * get_empty_filp(void) f->f_gid = current->fsgid; f->f_owner.lock = RW_LOCK_UNLOCKED; list_add(&f->f_list, &anon_list); - file_notify_init(f); file_list_unlock(); return f; } @@ -104,7 +103,6 @@ int init_private_file(struct file *filp, struct dentry *dentry, int mode) filp->f_uid = current->fsuid; filp->f_gid = current->fsgid; filp->f_op = dentry->d_inode->i_fop; - file_notify_init(filp); if (filp->f_op->open) return filp->f_op->open(dentry->d_inode, filp); else @@ -126,7 +124,7 @@ void __fput(struct file * file) struct vfsmount * mnt = file->f_vfsmnt; struct inode * inode = dentry->d_inode; - file_notify_cleanup(file); + ep_notify_file_close(file); locks_remove_flock(file); if (file->f_op && file->f_op->release) diff --git a/fs/pipe.c b/fs/pipe.c index ae448b0b1aa6..444172099d11 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -11,7 +11,6 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> -#include <linux/fcblist.h> #include <asm/uaccess.h> #include <asm/ioctls.h> @@ -47,7 +46,7 @@ static ssize_t pipe_read(struct file *filp, char *buf, size_t count, loff_t *ppos) { struct inode *inode = filp->f_dentry->d_inode; - int do_wakeup, pfull; + int do_wakeup; ssize_t ret; /* pread is not allowed on pipes. */ @@ -63,7 +62,6 @@ pipe_read(struct file *filp, char *buf, size_t count, loff_t *ppos) down(PIPE_SEM(*inode)); for (;;) { int size = PIPE_LEN(*inode); - pfull = PIPE_FULL(*inode); if (size) { char *pipebuf = PIPE_BASE(*inode) + PIPE_START(*inode); ssize_t chars = PIPE_MAX_RCHUNK(*inode); @@ -109,18 +107,12 @@ pipe_read(struct file *filp, char *buf, size_t count, loff_t *ppos) if (!ret) ret = -ERESTARTSYS; break; } - /* Send notification message */ - if (pfull && !PIPE_FULL(*inode) && PIPE_WRITEFILE(*inode)) - file_send_notify(PIPE_WRITEFILE(*inode), ION_OUT, POLLOUT | POLLWRNORM | POLLWRBAND); if (do_wakeup) { wake_up_interruptible_sync(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); } pipe_wait(inode); } - /* Send notification message */ - if (pfull && !PIPE_FULL(*inode) && PIPE_WRITEFILE(*inode)) - file_send_notify(PIPE_WRITEFILE(*inode), ION_OUT, POLLOUT | POLLWRNORM | POLLWRBAND); up(PIPE_SEM(*inode)); /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { @@ -138,7 +130,7 @@ pipe_write(struct file *filp, const char *buf, size_t count, loff_t *ppos) struct inode *inode = filp->f_dentry->d_inode; ssize_t ret; size_t min; - int do_wakeup, pempty; + int do_wakeup; /* pwrite is not allowed on pipes. */ if (unlikely(ppos != &filp->f_pos)) @@ -156,7 +148,6 @@ pipe_write(struct file *filp, const char *buf, size_t count, loff_t *ppos) down(PIPE_SEM(*inode)); for (;;) { int free; - pempty = PIPE_EMPTY(*inode); if (!PIPE_READERS(*inode)) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; @@ -202,9 +193,6 @@ pipe_write(struct file *filp, const char *buf, size_t count, loff_t *ppos) if (!ret) ret = -ERESTARTSYS; break; } - /* Send notification message */ - if (pempty && !PIPE_EMPTY(*inode) && PIPE_READFILE(*inode)) - file_send_notify(PIPE_READFILE(*inode), ION_IN, POLLIN | POLLRDNORM); if (do_wakeup) { wake_up_interruptible_sync(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); @@ -214,9 +202,6 @@ pipe_write(struct file *filp, const char *buf, size_t count, loff_t *ppos) pipe_wait(inode); PIPE_WAITING_WRITERS(*inode)--; } - /* Send notification message */ - if (pempty && !PIPE_EMPTY(*inode) && PIPE_READFILE(*inode)) - file_send_notify(PIPE_READFILE(*inode), ION_IN, POLLIN | POLLRDNORM); up(PIPE_SEM(*inode)); if (do_wakeup) { wake_up_interruptible(PIPE_WAIT(*inode)); @@ -280,22 +265,9 @@ pipe_poll(struct file *filp, poll_table *wait) static int pipe_release(struct inode *inode, int decr, int decw) { - struct file *rdfile, *wrfile; down(PIPE_SEM(*inode)); PIPE_READERS(*inode) -= decr; PIPE_WRITERS(*inode) -= decw; - rdfile = PIPE_READFILE(*inode); - wrfile = PIPE_WRITEFILE(*inode); - if (decr && !PIPE_READERS(*inode)) { - PIPE_READFILE(*inode) = NULL; - if (wrfile) - file_send_notify(wrfile, ION_HUP, POLLHUP); - } - if (decw && !PIPE_WRITERS(*inode)) { - PIPE_WRITEFILE(*inode) = NULL; - if (rdfile) - file_send_notify(rdfile, ION_HUP, POLLHUP); - } if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode)) { struct pipe_inode_info *info = inode->i_pipe; inode->i_pipe = NULL; @@ -515,7 +487,6 @@ struct inode* pipe_new(struct inode* inode) PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0; PIPE_WAITING_WRITERS(*inode) = 0; PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1; - PIPE_READFILE(*inode) = PIPE_WRITEFILE(*inode) = NULL; *PIPE_FASYNC_READERS(*inode) = *PIPE_FASYNC_WRITERS(*inode) = NULL; return inode; @@ -624,9 +595,6 @@ int do_pipe(int *fd) f2->f_mode = 2; f2->f_version = 0; - PIPE_READFILE(*inode) = f1; - PIPE_WRITEFILE(*inode) = f2; - fd_install(i, f1); fd_install(j, f2); fd[0] = i; diff --git a/fs/select.c b/fs/select.c index 30c29f1e49f8..0e2974a8154d 100644 --- a/fs/select.c +++ b/fs/select.c @@ -77,6 +77,14 @@ void __pollwait(struct file * filp, wait_queue_head_t * wait_address, poll_table { struct poll_table_page *table = p->table; + if (!p->queue) + return; + + if (p->qproc) { + p->qproc(p->priv, wait_address); + return; + } + if (!table || POLL_TABLE_FULL(table)) { struct poll_table_page *new_table; diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h index c028d5b7576b..4a26e6520823 100644 --- a/include/linux/eventpoll.h +++ b/include/linux/eventpoll.h @@ -1,6 +1,6 @@ /* * include/linux/eventpoll.h ( Efficent event polling implementation ) - * Copyright (C) 2001,...,2002 Davide Libenzi + * Copyright (C) 2001,...,2002 Davide Libenzi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -14,37 +14,25 @@ #ifndef _LINUX_EVENTPOLL_H #define _LINUX_EVENTPOLL_H +/* Forward declarations to avoid compiler errors */ +struct file; +struct pollfd; -#define EVENTPOLL_MINOR 124 -#define POLLFD_X_PAGE (PAGE_SIZE / sizeof(struct pollfd)) -#define MAX_FDS_IN_EVENTPOLL (1024 * 128) -#define MAX_EVENTPOLL_PAGES (MAX_FDS_IN_EVENTPOLL / POLLFD_X_PAGE) -#define EVENT_PAGE_INDEX(n) ((n) / POLLFD_X_PAGE) -#define EVENT_PAGE_REM(n) ((n) % POLLFD_X_PAGE) -#define EVENT_PAGE_OFFSET(n) (((n) % POLLFD_X_PAGE) * sizeof(struct pollfd)) -#define EP_FDS_PAGES(n) (((n) + POLLFD_X_PAGE - 1) / POLLFD_X_PAGE) -#define EP_MAP_SIZE(n) (EP_FDS_PAGES(n) * PAGE_SIZE * 2) - - -struct evpoll { - int ep_timeout; - unsigned long ep_resoff; -}; - -#define EP_ALLOC _IOR('P', 1, int) -#define EP_POLL _IOWR('P', 2, struct evpoll) -#define EP_FREE _IO('P', 3) -#define EP_ISPOLLED _IOWR('P', 4, struct pollfd) +/* Valid opcodes to issue to sys_epoll_ctl() */ #define EP_CTL_ADD 1 #define EP_CTL_DEL 2 #define EP_CTL_MOD 3 -asmlinkage int sys_epoll_create(int maxfds); +/* Kernel space functions implementing the user space "epoll" API */ +asmlinkage int sys_epoll_create(int size); asmlinkage int sys_epoll_ctl(int epfd, int op, int fd, unsigned int events); -asmlinkage int sys_epoll_wait(int epfd, struct pollfd const **events, int timeout); +asmlinkage int sys_epoll_wait(int epfd, struct pollfd *events, int maxevents, + int timeout); +/* Used in fs/file_table.c:__fput() to unlink files from the eventpoll interface */ +void ep_notify_file_close(struct file *file); #endif diff --git a/include/linux/fcblist.h b/include/linux/fcblist.h deleted file mode 100644 index 85be93ae40fd..000000000000 --- a/include/linux/fcblist.h +++ /dev/null @@ -1,71 +0,0 @@ -/* - * include/linux/fcblist.h ( File event callbacks handling ) - * Copyright (C) 2001,...,2002 Davide Libenzi - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * Davide Libenzi <davidel@xmailserver.org> - * - */ - -#ifndef __LINUX_FCBLIST_H -#define __LINUX_FCBLIST_H - -#include <linux/config.h> -#include <linux/list.h> -#include <linux/spinlock.h> -#include <linux/fs.h> -#include <linux/file.h> - - - -/* file callback notification events */ -#define ION_IN 1 -#define ION_OUT 2 -#define ION_HUP 3 -#define ION_ERR 4 - -#define FCB_LOCAL_SIZE 4 - - -struct fcb_struct { - struct list_head llink; - void (*cbproc)(struct file *, void *, unsigned long *, long *); - void *data; - unsigned long local[FCB_LOCAL_SIZE]; -}; - - -extern long ion_band_table[]; -extern long poll_band_table[]; - - -void file_notify_event(struct file *filep, long *event); - -int file_notify_addcb(struct file *filep, - void (*cbproc)(struct file *, void *, unsigned long *, long *), - void *data); - -int file_notify_delcb(struct file *filep, - void (*cbproc)(struct file *, void *, unsigned long *, long *)); - -void file_notify_cleanup(struct file *filep); - - -static inline void file_notify_init(struct file *filep) -{ - rwlock_init(&filep->f_cblock); - INIT_LIST_HEAD(&filep->f_cblist); -} - -static inline void file_send_notify(struct file *filep, long ioevt, long plevt) -{ - long event[] = { ioevt, plevt, -1 }; - - file_notify_event(filep, event); -} - -#endif diff --git a/include/linux/fs.h b/include/linux/fs.h index e83237a05110..c100c6297103 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -506,10 +506,6 @@ struct file { /* needed for tty driver, and maybe others */ void *private_data; - - /* file callback list */ - rwlock_t f_cblock; - struct list_head f_cblist; }; extern spinlock_t files_lock; #define file_list_lock() spin_lock(&files_lock); diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index bdf0a3686916..407c0e0b3e84 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -12,8 +12,6 @@ struct pipe_inode_info { unsigned int waiting_writers; unsigned int r_counter; unsigned int w_counter; - struct file *rdfile; - struct file *wrfile; struct fasync_struct *fasync_readers; struct fasync_struct *fasync_writers; }; @@ -32,8 +30,6 @@ struct pipe_inode_info { #define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers) #define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter) #define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter) -#define PIPE_READFILE(inode) ((inode).i_pipe->rdfile) -#define PIPE_WRITEFILE(inode) ((inode).i_pipe->wrfile) #define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers)) #define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers)) diff --git a/include/linux/poll.h b/include/linux/poll.h index 796aac51388a..318ff6ab5a53 100644 --- a/include/linux/poll.h +++ b/include/linux/poll.h @@ -13,6 +13,9 @@ struct poll_table_page; typedef struct poll_table_struct { + int queue; + void *priv; + void (*qproc)(void *, wait_queue_head_t *); int error; struct poll_table_page * table; } poll_table; @@ -27,9 +30,24 @@ static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_addres static inline void poll_initwait(poll_table* pt) { + pt->queue = 1; + pt->qproc = NULL; + pt->priv = NULL; pt->error = 0; pt->table = NULL; } + +static inline void poll_initwait_ex(poll_table* pt, int queue, + void (*qproc)(void *, wait_queue_head_t *), + void *priv) +{ + pt->queue = queue; + pt->qproc = qproc; + pt->priv = priv; + pt->error = 0; + pt->table = NULL; +} + extern void poll_freewait(poll_table* pt); diff --git a/include/net/sock.h b/include/net/sock.h index 4a4094b93d07..d2790e2ca00a 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -52,9 +52,6 @@ #include <asm/atomic.h> #include <net/dst.h> #include <net/scm.h> -#include <linux/fs.h> -#include <linux/file.h> -#include <linux/fcblist.h> /* * This structure really needs to be cleaned up. @@ -769,13 +766,8 @@ static inline unsigned long sock_wspace(struct sock *sk) static inline void sk_wake_async(struct sock *sk, int how, int band) { - if (sk->socket) { - if (sk->socket->file) - file_send_notify(sk->socket->file, ion_band_table[band - POLL_IN], - poll_band_table[band - POLL_IN]); - if (sk->socket->fasync_list) - sock_wake_async(sk->socket, how, band); - } + if (sk->socket && sk->socket->fasync_list) + sock_wake_async(sk->socket, how, band); } #define SOCK_MIN_SNDBUF 2048 diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c737b6f94414..e7c122e30969 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -476,8 +476,8 @@ void tcp_write_space(struct sock *sk) if (sk->sleep && waitqueue_active(sk->sleep)) wake_up_interruptible(sk->sleep); - if (!(sk->shutdown & SEND_SHUTDOWN)) - sk_wake_async(sk, 2, POLL_OUT); + if (sock->fasync_list && !(sk->shutdown & SEND_SHUTDOWN)) + sock_wake_async(sock, 2, POLL_OUT); } } |