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path: root/fs/notify/fanotify/fanotify_user.c
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Diffstat (limited to 'fs/notify/fanotify/fanotify_user.c')
-rw-r--r--fs/notify/fanotify/fanotify_user.c197
1 files changed, 77 insertions, 120 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 287a22c04149..4e565c814309 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -28,14 +28,8 @@
extern const struct fsnotify_ops fanotify_fsnotify_ops;
static struct kmem_cache *fanotify_mark_cache __read_mostly;
-static struct kmem_cache *fanotify_response_event_cache __read_mostly;
struct kmem_cache *fanotify_event_cachep __read_mostly;
-
-struct fanotify_response_event {
- struct list_head list;
- __s32 fd;
- struct fanotify_event_info *event;
-};
+struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
/*
* Get an fsnotify notification event if one exists and is small
@@ -135,33 +129,34 @@ static int fill_event_metadata(struct fsnotify_group *group,
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group,
- __s32 fd)
+static struct fanotify_perm_event_info *dequeue_event(
+ struct fsnotify_group *group, int fd)
{
- struct fanotify_response_event *re, *return_re = NULL;
+ struct fanotify_perm_event_info *event, *return_e = NULL;
- mutex_lock(&group->fanotify_data.access_mutex);
- list_for_each_entry(re, &group->fanotify_data.access_list, list) {
- if (re->fd != fd)
+ spin_lock(&group->fanotify_data.access_lock);
+ list_for_each_entry(event, &group->fanotify_data.access_list,
+ fae.fse.list) {
+ if (event->fd != fd)
continue;
- list_del_init(&re->list);
- return_re = re;
+ list_del_init(&event->fae.fse.list);
+ return_e = event;
break;
}
- mutex_unlock(&group->fanotify_data.access_mutex);
+ spin_unlock(&group->fanotify_data.access_lock);
- pr_debug("%s: found return_re=%p\n", __func__, return_re);
+ pr_debug("%s: found return_re=%p\n", __func__, return_e);
- return return_re;
+ return return_e;
}
static int process_access_response(struct fsnotify_group *group,
struct fanotify_response *response_struct)
{
- struct fanotify_response_event *re;
- __s32 fd = response_struct->fd;
- __u32 response = response_struct->response;
+ struct fanotify_perm_event_info *event;
+ int fd = response_struct->fd;
+ int response = response_struct->response;
pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
fd, response);
@@ -181,58 +176,15 @@ static int process_access_response(struct fsnotify_group *group,
if (fd < 0)
return -EINVAL;
- re = dequeue_re(group, fd);
- if (!re)
+ event = dequeue_event(group, fd);
+ if (!event)
return -ENOENT;
- re->event->response = response;
-
+ event->response = response;
wake_up(&group->fanotify_data.access_waitq);
- kmem_cache_free(fanotify_response_event_cache, re);
-
- return 0;
-}
-
-static int prepare_for_access_response(struct fsnotify_group *group,
- struct fsnotify_event *event,
- __s32 fd)
-{
- struct fanotify_response_event *re;
-
- if (!(event->mask & FAN_ALL_PERM_EVENTS))
- return 0;
-
- re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL);
- if (!re)
- return -ENOMEM;
-
- re->event = FANOTIFY_E(event);
- re->fd = fd;
-
- mutex_lock(&group->fanotify_data.access_mutex);
-
- if (atomic_read(&group->fanotify_data.bypass_perm)) {
- mutex_unlock(&group->fanotify_data.access_mutex);
- kmem_cache_free(fanotify_response_event_cache, re);
- FANOTIFY_E(event)->response = FAN_ALLOW;
- return 0;
- }
-
- list_add_tail(&re->list, &group->fanotify_data.access_list);
- mutex_unlock(&group->fanotify_data.access_mutex);
-
- return 0;
-}
-
-#else
-static int prepare_for_access_response(struct fsnotify_group *group,
- struct fsnotify_event *event,
- __s32 fd)
-{
return 0;
}
-
#endif
static ssize_t copy_event_to_user(struct fsnotify_group *group,
@@ -247,7 +199,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f);
if (ret < 0)
- goto out;
+ return ret;
fd = fanotify_event_metadata.fd;
ret = -EFAULT;
@@ -255,9 +207,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
fanotify_event_metadata.event_len))
goto out_close_fd;
- ret = prepare_for_access_response(group, event, fd);
- if (ret)
- goto out_close_fd;
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (event->mask & FAN_ALL_PERM_EVENTS)
+ FANOTIFY_PE(event)->fd = fd;
+#endif
if (fd != FAN_NOFD)
fd_install(fd, f);
@@ -268,13 +221,6 @@ out_close_fd:
put_unused_fd(fd);
fput(f);
}
-out:
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (event->mask & FAN_ALL_PERM_EVENTS) {
- FANOTIFY_E(event)->response = FAN_DENY;
- wake_up(&group->fanotify_data.access_waitq);
- }
-#endif
return ret;
}
@@ -314,35 +260,50 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
kevent = get_one_event(group, count);
mutex_unlock(&group->notification_mutex);
- if (kevent) {
+ if (IS_ERR(kevent)) {
ret = PTR_ERR(kevent);
- if (IS_ERR(kevent))
+ break;
+ }
+
+ if (!kevent) {
+ ret = -EAGAIN;
+ if (file->f_flags & O_NONBLOCK)
break;
- ret = copy_event_to_user(group, kevent, buf);
- /*
- * Permission events get destroyed after we
- * receive response
- */
- if (!(kevent->mask & FAN_ALL_PERM_EVENTS))
- fsnotify_destroy_event(group, kevent);
- if (ret < 0)
+
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+
+ if (start != buf)
break;
- buf += ret;
- count -= ret;
+ schedule();
continue;
}
- ret = -EAGAIN;
- if (file->f_flags & O_NONBLOCK)
- break;
- ret = -ERESTARTSYS;
- if (signal_pending(current))
- break;
-
- if (start != buf)
- break;
-
- schedule();
+ ret = copy_event_to_user(group, kevent, buf);
+ /*
+ * Permission events get queued to wait for response. Other
+ * events can be destroyed now.
+ */
+ if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) {
+ fsnotify_destroy_event(group, kevent);
+ if (ret < 0)
+ break;
+ } else {
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (ret < 0) {
+ FANOTIFY_PE(kevent)->response = FAN_DENY;
+ wake_up(&group->fanotify_data.access_waitq);
+ break;
+ }
+ spin_lock(&group->fanotify_data.access_lock);
+ list_add_tail(&kevent->list,
+ &group->fanotify_data.access_list);
+ spin_unlock(&group->fanotify_data.access_lock);
+#endif
+ }
+ buf += ret;
+ count -= ret;
}
finish_wait(&group->notification_waitq, &wait);
@@ -383,22 +344,21 @@ static int fanotify_release(struct inode *ignored, struct file *file)
struct fsnotify_group *group = file->private_data;
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- struct fanotify_response_event *re, *lre;
+ struct fanotify_perm_event_info *event, *next;
- mutex_lock(&group->fanotify_data.access_mutex);
+ spin_lock(&group->fanotify_data.access_lock);
atomic_inc(&group->fanotify_data.bypass_perm);
- list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) {
- pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group,
- re, re->event);
+ list_for_each_entry_safe(event, next, &group->fanotify_data.access_list,
+ fae.fse.list) {
+ pr_debug("%s: found group=%p event=%p\n", __func__, group,
+ event);
- list_del_init(&re->list);
- re->event->response = FAN_ALLOW;
-
- kmem_cache_free(fanotify_response_event_cache, re);
+ list_del_init(&event->fae.fse.list);
+ event->response = FAN_ALLOW;
}
- mutex_unlock(&group->fanotify_data.access_mutex);
+ spin_unlock(&group->fanotify_data.access_lock);
wake_up(&group->fanotify_data.access_waitq);
#endif
@@ -731,21 +691,16 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
group->fanotify_data.user = user;
atomic_inc(&user->fanotify_listeners);
- oevent = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL);
+ oevent = fanotify_alloc_event(NULL, FS_Q_OVERFLOW, NULL);
if (unlikely(!oevent)) {
fd = -ENOMEM;
goto out_destroy_group;
}
group->overflow_event = &oevent->fse;
- fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW);
- oevent->tgid = get_pid(task_tgid(current));
- oevent->path.mnt = NULL;
- oevent->path.dentry = NULL;
group->fanotify_data.f_flags = event_f_flags;
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- oevent->response = 0;
- mutex_init(&group->fanotify_data.access_mutex);
+ spin_lock_init(&group->fanotify_data.access_lock);
init_waitqueue_head(&group->fanotify_data.access_waitq);
INIT_LIST_HEAD(&group->fanotify_data.access_list);
atomic_set(&group->fanotify_data.bypass_perm, 0);
@@ -920,9 +875,11 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark,
static int __init fanotify_user_setup(void)
{
fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
- fanotify_response_event_cache = KMEM_CACHE(fanotify_response_event,
- SLAB_PANIC);
fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info,
+ SLAB_PANIC);
+#endif
return 0;
}