Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify: inotify: inotify_destroy_mark_entry could get called twice
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@ -15,7 +15,8 @@ struct inotify_inode_mark_entry {
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int wd;
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};
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extern void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group);
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extern void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
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struct fsnotify_group *group);
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extern void inotify_free_event_priv(struct fsnotify_event_private_data *event_priv);
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extern const struct fsnotify_ops inotify_fsnotify_ops;
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@ -81,7 +81,7 @@ static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_ev
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static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
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{
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inotify_destroy_mark_entry(entry, group);
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inotify_ignored_and_remove_idr(entry, group);
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}
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static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
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@ -363,39 +363,17 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
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}
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/*
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* When, for whatever reason, inotify is done with a mark (or what used to be a
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* watch) we need to remove that watch from the idr and we need to send IN_IGNORED
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* for the given wd.
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*
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* There is a bit of recursion here. The loop looks like:
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* inotify_destroy_mark_entry -> fsnotify_destroy_mark_by_entry ->
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* inotify_freeing_mark -> inotify_destory_mark_entry -> restart
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* But the loop is broken in 2 places. fsnotify_destroy_mark_by_entry sets
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* entry->group = NULL before the call to inotify_freeing_mark, so the if (egroup)
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* test below will not call back to fsnotify again. But even if that test wasn't
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* there this would still be safe since fsnotify_destroy_mark_by_entry() is
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* safe from recursion.
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* Send IN_IGNORED for this wd, remove this wd from the idr, and drop the
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* internal reference help on the mark because it is in the idr.
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*/
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void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
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void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
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struct fsnotify_group *group)
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{
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struct inotify_inode_mark_entry *ientry;
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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_group *egroup;
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struct idr *idr;
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spin_lock(&entry->lock);
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egroup = entry->group;
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/* if egroup we aren't really done and something might still send events
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* for this inode, on the callback we'll send the IN_IGNORED */
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if (egroup) {
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spin_unlock(&entry->lock);
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fsnotify_destroy_mark_by_entry(entry);
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return;
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}
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spin_unlock(&entry->lock);
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ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
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event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
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@ -699,7 +677,7 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
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fsnotify_get_mark(entry);
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spin_unlock(&group->inotify_data.idr_lock);
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inotify_destroy_mark_entry(entry, group);
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fsnotify_destroy_mark_by_entry(entry);
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fsnotify_put_mark(entry);
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out:
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