forked from Minki/linux
2069601b3f
This reverts commit3bcf3860a4
(and the accompanying commitc1e5c95402
"vfs/fsnotify: fsnotify_close can delay the final work in fput" that was a horribly ugly hack to make it work at all). The 'struct file' approach not only causes that disgusting hack, it somehow breaks pulseaudio, probably due to some other subtlety with f_count handling. Fix up various conflicts due to later fsnotify work. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
222 lines
6.4 KiB
C
222 lines
6.4 KiB
C
/*
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* fs/inotify_user.c - inotify support for userspace
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*
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* Authors:
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* John McCutchan <ttb@tentacle.dhs.org>
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* Robert Love <rml@novell.com>
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*
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* Copyright (C) 2005 John McCutchan
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* Copyright 2006 Hewlett-Packard Development Company, L.P.
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*
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* Copyright (C) 2009 Eric Paris <Red Hat Inc>
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* inotify was largely rewriten to make use of the fsnotify infrastructure
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/dcache.h> /* d_unlinked */
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#include <linux/fs.h> /* struct inode */
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#include <linux/fsnotify_backend.h>
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#include <linux/inotify.h>
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#include <linux/path.h> /* struct path */
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#include <linux/slab.h> /* kmem_* */
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#include <linux/types.h>
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#include <linux/sched.h>
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#include "inotify.h"
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/*
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* Check if 2 events contain the same information. We do not compare private data
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* but at this moment that isn't a problem for any know fsnotify listeners.
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*/
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static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new)
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{
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if ((old->mask == new->mask) &&
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(old->to_tell == new->to_tell) &&
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(old->data_type == new->data_type) &&
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(old->name_len == new->name_len)) {
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switch (old->data_type) {
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case (FSNOTIFY_EVENT_INODE):
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/* remember, after old was put on the wait_q we aren't
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* allowed to look at the inode any more, only thing
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* left to check was if the file_name is the same */
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if (!old->name_len ||
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!strcmp(old->file_name, new->file_name))
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return true;
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break;
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case (FSNOTIFY_EVENT_PATH):
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if ((old->path.mnt == new->path.mnt) &&
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(old->path.dentry == new->path.dentry))
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return true;
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break;
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case (FSNOTIFY_EVENT_NONE):
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if (old->mask & FS_Q_OVERFLOW)
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return true;
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else if (old->mask & FS_IN_IGNORED)
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return false;
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return true;
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};
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}
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return false;
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}
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static struct fsnotify_event *inotify_merge(struct list_head *list,
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struct fsnotify_event *event)
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{
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struct fsnotify_event_holder *last_holder;
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struct fsnotify_event *last_event;
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/* and the list better be locked by something too */
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spin_lock(&event->lock);
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last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list);
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last_event = last_holder->event;
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if (event_compare(last_event, event))
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fsnotify_get_event(last_event);
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else
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last_event = NULL;
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spin_unlock(&event->lock);
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return last_event;
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}
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static int inotify_handle_event(struct fsnotify_group *group,
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struct fsnotify_mark *inode_mark,
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struct fsnotify_mark *vfsmount_mark,
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struct fsnotify_event *event)
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{
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struct inotify_inode_mark *i_mark;
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struct inode *to_tell;
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struct inotify_event_private_data *event_priv;
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struct fsnotify_event_private_data *fsn_event_priv;
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struct fsnotify_event *added_event;
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int wd, ret = 0;
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BUG_ON(vfsmount_mark);
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pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group,
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event, event->to_tell, event->mask);
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to_tell = event->to_tell;
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i_mark = container_of(inode_mark, struct inotify_inode_mark,
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fsn_mark);
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wd = i_mark->wd;
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event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
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if (unlikely(!event_priv))
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return -ENOMEM;
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fsn_event_priv = &event_priv->fsnotify_event_priv_data;
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fsn_event_priv->group = group;
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event_priv->wd = wd;
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added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge);
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if (added_event) {
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inotify_free_event_priv(fsn_event_priv);
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if (!IS_ERR(added_event))
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fsnotify_put_event(added_event);
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else
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ret = PTR_ERR(added_event);
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}
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if (inode_mark->mask & IN_ONESHOT)
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fsnotify_destroy_mark(inode_mark);
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return ret;
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}
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static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
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{
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inotify_ignored_and_remove_idr(fsn_mark, group);
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}
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static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode,
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struct fsnotify_mark *inode_mark,
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struct fsnotify_mark *vfsmount_mark,
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__u32 mask, void *data, int data_type)
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{
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if ((inode_mark->mask & FS_EXCL_UNLINK) &&
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(data_type == FSNOTIFY_EVENT_PATH)) {
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struct path *path = data;
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if (d_unlinked(path->dentry))
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return false;
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}
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return true;
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}
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/*
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* This is NEVER supposed to be called. Inotify marks should either have been
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* removed from the idr when the watch was removed or in the
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* fsnotify_destroy_mark_by_group() call when the inotify instance was being
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* torn down. This is only called if the idr is about to be freed but there
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* are still marks in it.
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*/
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static int idr_callback(int id, void *p, void *data)
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{
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struct fsnotify_mark *fsn_mark;
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struct inotify_inode_mark *i_mark;
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static bool warned = false;
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if (warned)
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return 0;
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warned = true;
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fsn_mark = p;
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i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
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WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in "
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"idr. Probably leaking memory\n", id, p, data);
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/*
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* I'm taking the liberty of assuming that the mark in question is a
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* valid address and I'm dereferencing it. This might help to figure
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* out why we got here and the panic is no worse than the original
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* BUG() that was here.
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*/
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if (fsn_mark)
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printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n",
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fsn_mark->group, fsn_mark->i.inode, i_mark->wd);
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return 0;
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}
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static void inotify_free_group_priv(struct fsnotify_group *group)
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{
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/* ideally the idr is empty and we won't hit the BUG in teh callback */
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idr_for_each(&group->inotify_data.idr, idr_callback, group);
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idr_remove_all(&group->inotify_data.idr);
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idr_destroy(&group->inotify_data.idr);
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free_uid(group->inotify_data.user);
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}
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void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)
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{
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struct inotify_event_private_data *event_priv;
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event_priv = container_of(fsn_event_priv, struct inotify_event_private_data,
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fsnotify_event_priv_data);
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kmem_cache_free(event_priv_cachep, event_priv);
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}
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const struct fsnotify_ops inotify_fsnotify_ops = {
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.handle_event = inotify_handle_event,
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.should_send_event = inotify_should_send_event,
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.free_group_priv = inotify_free_group_priv,
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.free_event_priv = inotify_free_event_priv,
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.freeing_mark = inotify_freeing_mark,
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};
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