--- /dev/null
+/*
+ * fs/inotify_user.c - inotify support for userspace
+ *
+ * Authors:
+ * John McCutchan <ttb@tentacle.dhs.org>
+ * Robert Love <rml@novell.com>
+ *
+ * Copyright (C) 2005 John McCutchan
+ * Copyright 2006 Hewlett-Packard Development Company, L.P.
+ *
+ * Copyright (C) 2009 Eric Paris <Red Hat Inc>
+ * inotify was largely rewriten to make use of the fsnotify infrastructure
+ *
+ * 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, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/dcache.h> /* d_unlinked */
+#include <linux/fs.h> /* struct inode */
+#include <linux/fsnotify_backend.h>
+#include <linux/inotify.h>
+#include <linux/path.h> /* struct path */
+#include <linux/slab.h> /* kmem_* */
+#include <linux/types.h>
+#include <linux/sched.h>
+
+#include "inotify.h"
+
+/*
+ * Check if 2 events contain the same information.
+ */
+static bool event_compare(struct fsnotify_event *old_fsn,
+ struct fsnotify_event *new_fsn)
+{
+ struct inotify_event_info *old, *new;
+
+ if (old_fsn->mask & FS_IN_IGNORED)
+ return false;
+ old = INOTIFY_E(old_fsn);
+ new = INOTIFY_E(new_fsn);
+ if ((old_fsn->mask == new_fsn->mask) &&
+ (old_fsn->inode == new_fsn->inode) &&
+ (old->name_len == new->name_len) &&
+ (!old->name_len || !strcmp(old->name, new->name)))
+ return true;
+ return false;
+}
+
+static int inotify_merge(struct list_head *list,
+ struct fsnotify_event *event)
+{
+ struct fsnotify_event *last_event;
+
+ last_event = list_entry(list->prev, struct fsnotify_event, list);
+ return event_compare(last_event, event);
+}
+
+int inotify_handle_event(struct fsnotify_group *group,
+ struct inode *inode,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ u32 mask, void *data, int data_type,
+ const unsigned char *file_name, u32 cookie)
+{
+ struct inotify_inode_mark *i_mark;
+ struct inotify_event_info *event;
+ struct fsnotify_event *fsn_event;
+ int ret;
+ int len = 0;
+ int alloc_len = sizeof(struct inotify_event_info);
+
+ BUG_ON(vfsmount_mark);
+
+ if ((inode_mark->mask & FS_EXCL_UNLINK) &&
+ (data_type == FSNOTIFY_EVENT_PATH)) {
+ struct path *path = data;
+
+ if (d_unlinked(path->dentry))
+ return 0;
+ }
+ if (file_name) {
+ len = strlen(file_name);
+ alloc_len += len + 1;
+ }
+
+ pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
+ mask);
+
+ i_mark = container_of(inode_mark, struct inotify_inode_mark,
+ fsn_mark);
+
+ event = kmalloc(alloc_len, GFP_KERNEL);
+ if (unlikely(!event))
+ return -ENOMEM;
+
+ fsn_event = &event->fse;
+ fsnotify_init_event(fsn_event, inode, mask);
+ event->wd = i_mark->wd;
+ event->sync_cookie = cookie;
+ event->name_len = len;
+ if (len)
+ strcpy(event->name, file_name);
+
+ ret = fsnotify_add_event(group, fsn_event, inotify_merge);
+ if (ret) {
+ /* Our event wasn't used in the end. Free it. */
+ fsnotify_destroy_event(group, fsn_event);
+ }
+
+ if (inode_mark->mask & IN_ONESHOT)
+ fsnotify_destroy_mark(inode_mark, group);
+
+ return 0;
+}
+
+static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
+{
+ inotify_ignored_and_remove_idr(fsn_mark, group);
+}
+
+/*
+ * This is NEVER supposed to be called. Inotify marks should either have been
+ * removed from the idr when the watch was removed or in the
+ * fsnotify_destroy_mark_by_group() call when the inotify instance was being
+ * torn down. This is only called if the idr is about to be freed but there
+ * are still marks in it.
+ */
+static int idr_callback(int id, void *p, void *data)
+{
+ struct fsnotify_mark *fsn_mark;
+ struct inotify_inode_mark *i_mark;
+ static bool warned = false;
+
+ if (warned)
+ return 0;
+
+ warned = true;
+ fsn_mark = p;
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
+
+ WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in "
+ "idr. Probably leaking memory\n", id, p, data);
+
+ /*
+ * I'm taking the liberty of assuming that the mark in question is a
+ * valid address and I'm dereferencing it. This might help to figure
+ * out why we got here and the panic is no worse than the original
+ * BUG() that was here.
+ */
+ if (fsn_mark)
+ printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n",
+ fsn_mark->group, fsn_mark->inode, i_mark->wd);
+ return 0;
+}
+
+static void inotify_free_group_priv(struct fsnotify_group *group)
+{
+ /* ideally the idr is empty and we won't hit the BUG in the callback */
+ idr_for_each(&group->inotify_data.idr, idr_callback, group);
+ idr_destroy(&group->inotify_data.idr);
+ if (group->inotify_data.user) {
+ atomic_dec(&group->inotify_data.user->inotify_devs);
+ free_uid(group->inotify_data.user);
+ }
+}
+
+static void inotify_free_event(struct fsnotify_event *fsn_event)
+{
+ kfree(INOTIFY_E(fsn_event));
+}
+
+const struct fsnotify_ops inotify_fsnotify_ops = {
+ .handle_event = inotify_handle_event,
+ .free_group_priv = inotify_free_group_priv,
+ .free_event = inotify_free_event,
+ .freeing_mark = inotify_freeing_mark,
+};
Code Review / kvmfornfv.git / blobdiff