#include <linux/types.h>
#include <linux/wait.h>
-static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new)
+#include "fanotify.h"
+
+static bool should_merge(struct fsnotify_event *old_fsn,
+ struct fsnotify_event *new_fsn)
{
- pr_debug("%s: old=%p new=%p\n", __func__, old, new);
+ struct fanotify_event_info *old, *new;
- if (old->to_tell == new->to_tell &&
- old->data_type == new->data_type &&
- old->tgid == new->tgid) {
- switch (old->data_type) {
- case (FSNOTIFY_EVENT_PATH):
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- /* dont merge two permission events */
- if ((old->mask & FAN_ALL_PERM_EVENTS) &&
- (new->mask & FAN_ALL_PERM_EVENTS))
- return false;
-#endif
- if ((old->path.mnt == new->path.mnt) &&
- (old->path.dentry == new->path.dentry))
- return true;
- break;
- case (FSNOTIFY_EVENT_NONE):
- return true;
- default:
- BUG();
- };
- }
+ pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn);
+ old = FANOTIFY_E(old_fsn);
+ new = FANOTIFY_E(new_fsn);
+
+ if (old_fsn->inode == new_fsn->inode && old->tgid == new->tgid &&
+ old->path.mnt == new->path.mnt &&
+ old->path.dentry == new->path.dentry)
+ return true;
return false;
}
/* and the list better be locked by something too! */
-static struct fsnotify_event *fanotify_merge(struct list_head *list,
- struct fsnotify_event *event)
+static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
{
- struct fsnotify_event_holder *test_holder;
- struct fsnotify_event *test_event = NULL;
- struct fsnotify_event *new_event;
+ struct fsnotify_event *test_event;
+ bool do_merge = false;
pr_debug("%s: list=%p event=%p\n", __func__, list, event);
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ /*
+ * Don't merge a permission event with any other event so that we know
+ * the event structure we have created in fanotify_handle_event() is the
+ * one we should check for permission response.
+ */
+ if (event->mask & FAN_ALL_PERM_EVENTS)
+ return 0;
+#endif
- list_for_each_entry_reverse(test_holder, list, event_list) {
- if (should_merge(test_holder->event, event)) {
- test_event = test_holder->event;
+ list_for_each_entry_reverse(test_event, list, list) {
+ if (should_merge(test_event, event)) {
+ do_merge = true;
break;
}
}
- if (!test_event)
- return NULL;
-
- fsnotify_get_event(test_event);
-
- /* if they are exactly the same we are done */
- if (test_event->mask == event->mask)
- return test_event;
-
- /*
- * if the refcnt == 2 this is the only queue
- * for this event and so we can update the mask
- * in place.
- */
- if (atomic_read(&test_event->refcnt) == 2) {
- test_event->mask |= event->mask;
- return test_event;
- }
-
- new_event = fsnotify_clone_event(test_event);
-
- /* done with test_event */
- fsnotify_put_event(test_event);
-
- /* couldn't allocate memory, merge was not possible */
- if (unlikely(!new_event))
- return ERR_PTR(-ENOMEM);
-
- /* build new event and replace it on the list */
- new_event->mask = (test_event->mask | event->mask);
- fsnotify_replace_event(test_holder, new_event);
+ if (!do_merge)
+ return 0;
- /* we hold a reference on new_event from clone_event */
- return new_event;
+ test_event->mask |= event->mask;
+ return 1;
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
static int fanotify_get_response_from_access(struct fsnotify_group *group,
- struct fsnotify_event *event)
+ struct fanotify_event_info *event)
{
int ret;
return 0;
/* userspace responded, convert to something usable */
- spin_lock(&event->lock);
switch (event->response) {
case FAN_ALLOW:
ret = 0;
ret = -EPERM;
}
event->response = 0;
- spin_unlock(&event->lock);
pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,
group, event, ret);
}
#endif
-static int fanotify_handle_event(struct fsnotify_group *group,
- struct fsnotify_mark *inode_mark,
- struct fsnotify_mark *fanotify_mark,
- struct fsnotify_event *event)
-{
- int ret = 0;
- struct fsnotify_event *notify_event = NULL;
-
- BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
- BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
- BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
- BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
- BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
- BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
- BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
- BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
- BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
- BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
-
- pr_debug("%s: group=%p event=%p\n", __func__, group, event);
-
- notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge);
- if (IS_ERR(notify_event))
- return PTR_ERR(notify_event);
-
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (event->mask & FAN_ALL_PERM_EVENTS) {
- /* if we merged we need to wait on the new event */
- if (notify_event)
- event = notify_event;
- ret = fanotify_get_response_from_access(group, event);
- }
-#endif
-
- if (notify_event)
- fsnotify_put_event(notify_event);
-
- return ret;
-}
-
-static bool fanotify_should_send_event(struct fsnotify_group *group,
- struct inode *to_tell,
- struct fsnotify_mark *inode_mark,
+static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark,
struct fsnotify_mark *vfsmnt_mark,
- __u32 event_mask, void *data, int data_type)
+ u32 event_mask,
+ void *data, int data_type)
{
__u32 marks_mask, marks_ignored_mask;
struct path *path = data;
- pr_debug("%s: group=%p to_tell=%p inode_mark=%p vfsmnt_mark=%p "
- "mask=%x data=%p data_type=%d\n", __func__, group, to_tell,
- inode_mark, vfsmnt_mark, event_mask, data, data_type);
+ pr_debug("%s: inode_mark=%p vfsmnt_mark=%p mask=%x data=%p"
+ " data_type=%d\n", __func__, inode_mark, vfsmnt_mark,
+ event_mask, data, data_type);
/* if we don't have enough info to send an event to userspace say no */
if (data_type != FSNOTIFY_EVENT_PATH)
return false;
}
+static int fanotify_handle_event(struct fsnotify_group *group,
+ struct inode *inode,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *fanotify_mark,
+ u32 mask, void *data, int data_type,
+ const unsigned char *file_name)
+{
+ int ret = 0;
+ struct fanotify_event_info *event;
+ struct fsnotify_event *fsn_event;
+
+ BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
+ BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
+ BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
+ BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
+ BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
+
+ if (!fanotify_should_send_event(inode_mark, fanotify_mark, mask, data,
+ data_type))
+ return 0;
+
+ pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
+ mask);
+
+ event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL);
+ if (unlikely(!event))
+ return -ENOMEM;
+
+ fsn_event = &event->fse;
+ fsnotify_init_event(fsn_event, inode, mask);
+ event->tgid = get_pid(task_tgid(current));
+ if (data_type == FSNOTIFY_EVENT_PATH) {
+ struct path *path = data;
+ event->path = *path;
+ path_get(&event->path);
+ } else {
+ event->path.mnt = NULL;
+ event->path.dentry = NULL;
+ }
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ event->response = 0;
+#endif
+
+ ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge);
+ if (ret) {
+ /* Our event wasn't used in the end. Free it. */
+ fsnotify_destroy_event(group, fsn_event);
+ ret = 0;
+ }
+
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (mask & FAN_ALL_PERM_EVENTS)
+ ret = fanotify_get_response_from_access(group, event);
+#endif
+ return ret;
+}
+
static void fanotify_free_group_priv(struct fsnotify_group *group)
{
struct user_struct *user;
free_uid(user);
}
+static void fanotify_free_event(struct fsnotify_event *fsn_event)
+{
+ struct fanotify_event_info *event;
+
+ event = FANOTIFY_E(fsn_event);
+ path_put(&event->path);
+ put_pid(event->tgid);
+ kmem_cache_free(fanotify_event_cachep, event);
+}
+
const struct fsnotify_ops fanotify_fsnotify_ops = {
.handle_event = fanotify_handle_event,
- .should_send_event = fanotify_should_send_event,
.free_group_priv = fanotify_free_group_priv,
- .free_event_priv = NULL,
- .freeing_mark = NULL,
+ .free_event = fanotify_free_event,
};
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