#include <linux/list.h>
#include <linux/inotify.h>
#include <linux/syscalls.h>
+#include <linux/magic.h>
#include <asm/ioctls.h>
-static kmem_cache_t *watch_cachep __read_mostly;
-static kmem_cache_t *event_cachep __read_mostly;
+static struct kmem_cache *watch_cachep __read_mostly;
+static struct kmem_cache *event_cachep __read_mostly;
static struct vfsmount *inotify_mnt __read_mostly;
/* these are configurable via /proc/sys/fs/inotify/ */
-int inotify_max_user_instances __read_mostly;
-int inotify_max_user_watches __read_mostly;
-int inotify_max_queued_events __read_mostly;
+static int inotify_max_user_instances __read_mostly;
+static int inotify_max_user_watches __read_mostly;
+static int inotify_max_queued_events __read_mostly;
/*
* Lock ordering:
atomic_t count; /* reference count */
struct user_struct *user; /* user who opened this dev */
struct inotify_handle *ih; /* inotify handle */
+ struct fasync_struct *fa; /* async notification */
unsigned int queue_size; /* size of the queue (bytes) */
unsigned int event_count; /* number of pending events */
unsigned int max_events; /* maximum number of events */
{
struct inotify_kernel_event *kevent;
- kevent = kmem_cache_alloc(event_cachep, GFP_KERNEL);
+ kevent = kmem_cache_alloc(event_cachep, GFP_NOFS);
if (unlikely(!kevent))
return NULL;
}
/*
+ * inotify_dev_get_last_event - return the last event in the given dev's queue
+ *
+ * Caller must hold dev->ev_mutex.
+ */
+static inline struct inotify_kernel_event *
+inotify_dev_get_last_event(struct inotify_device *dev)
+{
+ if (list_empty(&dev->events))
+ return NULL;
+ return list_entry(dev->events.prev, struct inotify_kernel_event, list);
+}
+
+/*
* inotify_dev_queue_event - event handler registered with core inotify, adds
* a new event to the given device
*
/* we can safely put the watch as we don't reference it while
* generating the event
*/
- if (mask & IN_IGNORED || mask & IN_ONESHOT)
+ if (mask & IN_IGNORED || w->mask & IN_ONESHOT)
put_inotify_watch(w); /* final put */
/* coalescing: drop this event if it is a dupe of the previous */
- last = inotify_dev_get_event(dev);
+ last = inotify_dev_get_last_event(dev);
if (last && last->event.mask == mask && last->event.wd == wd &&
last->event.cookie == cookie) {
const char *lastname = last->name;
dev->queue_size += sizeof(struct inotify_event) + kevent->event.len;
list_add_tail(&kevent->list, &dev->events);
wake_up_interruptible(&dev->wq);
+ kill_fasync(&dev->fa, SIGIO, POLL_IN);
out:
mutex_unlock(&dev->ev_mutex);
}
/*
- * remove_kevent - cleans up and ultimately frees the given kevent
+ * remove_kevent - cleans up the given kevent
*
* Caller must hold dev->ev_mutex.
*/
dev->event_count--;
dev->queue_size -= sizeof(struct inotify_event) + kevent->event.len;
+}
+/*
+ * free_kevent - frees the given kevent.
+ */
+static void free_kevent(struct inotify_kernel_event *kevent)
+{
kfree(kevent->name);
kmem_cache_free(event_cachep, kevent);
}
struct inotify_kernel_event *kevent;
kevent = inotify_dev_get_event(dev);
remove_kevent(dev, kevent);
+ free_kevent(kevent);
}
}
/*
- * find_inode - resolve a user-given path to a specific inode and return a nd
+ * find_inode - resolve a user-given path to a specific inode
*/
-static int find_inode(const char __user *dirname, struct nameidata *nd,
+static int find_inode(const char __user *dirname, struct path *path,
unsigned flags)
{
int error;
- error = __user_walk(dirname, flags, nd);
+ error = user_path_at(AT_FDCWD, dirname, flags, path);
if (error)
return error;
/* you can only watch an inode if you have read permissions on it */
- error = vfs_permission(nd, MAY_READ);
+ error = inode_permission(path->dentry->d_inode, MAY_READ);
if (error)
- path_release(nd);
+ path_put(path);
return error;
}
atomic_inc(&dev->user->inotify_watches);
+ inotify_init_watch(&watch->wdata);
ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);
if (ret < 0)
free_inotify_user_watch(&watch->wdata);
dev = file->private_data;
while (1) {
- int events;
prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
mutex_lock(&dev->ev_mutex);
- events = !list_empty(&dev->events);
- mutex_unlock(&dev->ev_mutex);
- if (events) {
+ if (!list_empty(&dev->events)) {
ret = 0;
break;
}
+ mutex_unlock(&dev->ev_mutex);
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
if (ret)
return ret;
- mutex_lock(&dev->ev_mutex);
while (1) {
struct inotify_kernel_event *kevent;
break;
kevent = inotify_dev_get_event(dev);
- if (event_size + kevent->event.len > count)
+ if (event_size + kevent->event.len > count) {
+ if (ret == 0 && count > 0) {
+ /*
+ * could not get a single event because we
+ * didn't have enough buffer space.
+ */
+ ret = -EINVAL;
+ }
break;
+ }
+ remove_kevent(dev, kevent);
+
+ /*
+ * Must perform the copy_to_user outside the mutex in order
+ * to avoid a lock order reversal with mmap_sem.
+ */
+ mutex_unlock(&dev->ev_mutex);
if (copy_to_user(buf, &kevent->event, event_size)) {
ret = -EFAULT;
count -= kevent->event.len;
}
- remove_kevent(dev, kevent);
+ free_kevent(kevent);
+
+ mutex_lock(&dev->ev_mutex);
}
mutex_unlock(&dev->ev_mutex);
return ret;
}
+static int inotify_fasync(int fd, struct file *file, int on)
+{
+ struct inotify_device *dev = file->private_data;
+
+ return fasync_helper(fd, file, on, &dev->fa) >= 0 ? 0 : -EIO;
+}
+
static int inotify_release(struct inode *ignored, struct file *file)
{
struct inotify_device *dev = file->private_data;
inotify_dev_event_dequeue(dev);
mutex_unlock(&dev->ev_mutex);
+ if (file->f_flags & FASYNC)
+ inotify_fasync(-1, file, 0);
+
/* free this device: the put matching the get in inotify_init() */
put_inotify_dev(dev);
static const struct file_operations inotify_fops = {
.poll = inotify_poll,
.read = inotify_read,
+ .fasync = inotify_fasync,
.release = inotify_release,
.unlocked_ioctl = inotify_ioctl,
.compat_ioctl = inotify_ioctl,
.destroy_watch = free_inotify_user_watch,
};
-asmlinkage long sys_inotify_init(void)
+asmlinkage long sys_inotify_init1(int flags)
{
struct inotify_device *dev;
struct inotify_handle *ih;
struct file *filp;
int fd, ret;
- fd = get_unused_fd();
+ /* Check the IN_* constants for consistency. */
+ BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
+ BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
+
+ if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
+ return -EINVAL;
+
+ fd = get_unused_fd_flags(flags & O_CLOEXEC);
if (fd < 0)
return fd;
}
ih = inotify_init(&inotify_user_ops);
- if (unlikely(IS_ERR(ih))) {
+ if (IS_ERR(ih)) {
ret = PTR_ERR(ih);
goto out_free_dev;
}
dev->ih = ih;
+ dev->fa = NULL;
filp->f_op = &inotify_fops;
- filp->f_vfsmnt = mntget(inotify_mnt);
- filp->f_dentry = dget(inotify_mnt->mnt_root);
- filp->f_mapping = filp->f_dentry->d_inode->i_mapping;
+ filp->f_path.mnt = mntget(inotify_mnt);
+ filp->f_path.dentry = dget(inotify_mnt->mnt_root);
+ filp->f_mapping = filp->f_path.dentry->d_inode->i_mapping;
filp->f_mode = FMODE_READ;
- filp->f_flags = O_RDONLY;
+ filp->f_flags = O_RDONLY | (flags & O_NONBLOCK);
filp->private_data = dev;
INIT_LIST_HEAD(&dev->events);
return ret;
}
-asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)
+asmlinkage long sys_inotify_init(void)
+{
+ return sys_inotify_init1(0);
+}
+
+asmlinkage long sys_inotify_add_watch(int fd, const char __user *pathname, u32 mask)
{
struct inode *inode;
struct inotify_device *dev;
- struct nameidata nd;
+ struct path path;
struct file *filp;
int ret, fput_needed;
unsigned flags = 0;
if (mask & IN_ONLYDIR)
flags |= LOOKUP_DIRECTORY;
- ret = find_inode(path, &nd, flags);
+ ret = find_inode(pathname, &path, flags);
if (unlikely(ret))
goto fput_and_out;
- /* inode held in place by reference to nd; dev by fget on fd */
- inode = nd.dentry->d_inode;
+ /* inode held in place by reference to path; dev by fget on fd */
+ inode = path.dentry->d_inode;
dev = filp->private_data;
mutex_lock(&dev->up_mutex);
ret = create_watch(dev, inode, mask);
mutex_unlock(&dev->up_mutex);
- path_release(&nd);
+ path_put(&path);
fput_and_out:
fput_light(filp, fput_needed);
return ret;
return ret;
}
-static struct super_block *
+static int
inotify_get_sb(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data)
+ const char *dev_name, void *data, struct vfsmount *mnt)
{
- return get_sb_pseudo(fs_type, "inotify", NULL, 0xBAD1DEA);
+ return get_sb_pseudo(fs_type, "inotify", NULL,
+ INOTIFYFS_SUPER_MAGIC, mnt);
}
static struct file_system_type inotify_fs_type = {
watch_cachep = kmem_cache_create("inotify_watch_cache",
sizeof(struct inotify_user_watch),
- 0, SLAB_PANIC, NULL, NULL);
+ 0, SLAB_PANIC, NULL);
event_cachep = kmem_cache_create("inotify_event_cache",
sizeof(struct inotify_kernel_event),
- 0, SLAB_PANIC, NULL, NULL);
+ 0, SLAB_PANIC, NULL);
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff