/* * 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/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 "inotify.h" static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event) { struct fsnotify_mark_entry *entry; struct inotify_inode_mark_entry *ientry; struct inode *to_tell; struct inotify_event_private_data *event_priv; struct fsnotify_event_private_data *fsn_event_priv; int wd, ret; to_tell = event->to_tell; spin_lock(&to_tell->i_lock); entry = fsnotify_find_mark_entry(group, to_tell); spin_unlock(&to_tell->i_lock); /* race with watch removal? We already passes should_send */ if (unlikely(!entry)) return 0; ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); wd = ientry->wd; event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); if (unlikely(!event_priv)) return -ENOMEM; fsn_event_priv = &event_priv->fsnotify_event_priv_data; fsn_event_priv->group = group; event_priv->wd = wd; ret = fsnotify_add_notify_event(group, event, fsn_event_priv); if (ret) { inotify_free_event_priv(fsn_event_priv); /* EEXIST says we tail matched, EOVERFLOW isn't something * to report up the stack. */ if ((ret == -EEXIST) || (ret == -EOVERFLOW)) ret = 0; } /* * If we hold the entry until after the event is on the queue * IN_IGNORED won't be able to pass this event in the queue */ fsnotify_put_mark(entry); return ret; } static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group) { inotify_ignored_and_remove_idr(entry, group); } static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask) { struct fsnotify_mark_entry *entry; bool send; spin_lock(&inode->i_lock); entry = fsnotify_find_mark_entry(group, inode); spin_unlock(&inode->i_lock); if (!entry) return false; mask = (mask & ~FS_EVENT_ON_CHILD); send = (entry->mask & mask); /* find took a reference */ fsnotify_put_mark(entry); return send; } /* * 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_entry *entry; struct inotify_inode_mark_entry *ientry; static bool warned = false; if (warned) return 0; warned = false; entry = p; ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); WARN(1, "inotify closing but id=%d for entry=%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 (entry) printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n", entry->group, entry->inode, ientry->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 teh callback */ idr_for_each(&group->inotify_data.idr, idr_callback, group); idr_remove_all(&group->inotify_data.idr); idr_destroy(&group->inotify_data.idr); } void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) { struct inotify_event_private_data *event_priv; event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, fsnotify_event_priv_data); kmem_cache_free(event_priv_cachep, event_priv); } const struct fsnotify_ops inotify_fsnotify_ops = { .handle_event = inotify_handle_event, .should_send_event = inotify_should_send_event, .free_group_priv = inotify_free_group_priv, .free_event_priv = inotify_free_event_priv, .freeing_mark = inotify_freeing_mark, };