/* * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> * * 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. * * You should have received a copy of the GNU General Public License * along with this program; see the file COPYING. If not, write to * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mount.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/atomic.h> #include <linux/fsnotify_backend.h> #include "fsnotify.h" void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group) { fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_VFSMOUNT); } /* * Recalculate the mnt->mnt_fsnotify_mask, or the mask of all FS_* event types * any notifier is interested in hearing for this mount point */ void fsnotify_recalc_vfsmount_mask(struct vfsmount *mnt) { struct mount *m = real_mount(mnt); spin_lock(&mnt->mnt_root->d_lock); m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks); spin_unlock(&mnt->mnt_root->d_lock); } void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark) { struct vfsmount *mnt = mark->mnt; struct mount *m = real_mount(mnt); BUG_ON(!mutex_is_locked(&mark->group->mark_mutex)); assert_spin_locked(&mark->lock); spin_lock(&mnt->mnt_root->d_lock); hlist_del_init_rcu(&mark->obj_list); mark->mnt = NULL; m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks); spin_unlock(&mnt->mnt_root->d_lock); } /* * given a group and vfsmount, find the mark associated with that combination. * if found take a reference to that mark and return it, else return NULL */ struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group, struct vfsmount *mnt) { struct mount *m = real_mount(mnt); struct fsnotify_mark *mark; spin_lock(&mnt->mnt_root->d_lock); mark = fsnotify_find_mark(&m->mnt_fsnotify_marks, group); spin_unlock(&mnt->mnt_root->d_lock); return mark; } /* * Attach an initialized mark to a given group and vfsmount. * These marks may be used for the fsnotify backend to determine which * event types should be delivered to which groups. */ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark, struct fsnotify_group *group, struct vfsmount *mnt, int allow_dups) { struct mount *m = real_mount(mnt); int ret; mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT; BUG_ON(!mutex_is_locked(&group->mark_mutex)); assert_spin_locked(&mark->lock); spin_lock(&mnt->mnt_root->d_lock); mark->mnt = mnt; ret = fsnotify_add_mark_list(&m->mnt_fsnotify_marks, mark, allow_dups); m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks); spin_unlock(&mnt->mnt_root->d_lock); return ret; }