mirror of https://gitee.com/openkylin/linux.git
109 lines
3.2 KiB
C
109 lines
3.2 KiB
C
/*
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* Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <linux/mutex.h>
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#include <linux/spinlock.h>
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#include <linux/atomic.h>
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#include <linux/fsnotify_backend.h>
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#include "fsnotify.h"
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void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
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{
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fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_VFSMOUNT);
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}
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/*
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* Recalculate the mnt->mnt_fsnotify_mask, or the mask of all FS_* event types
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* any notifier is interested in hearing for this mount point
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*/
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void fsnotify_recalc_vfsmount_mask(struct vfsmount *mnt)
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{
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struct mount *m = real_mount(mnt);
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spin_lock(&mnt->mnt_root->d_lock);
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m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
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spin_unlock(&mnt->mnt_root->d_lock);
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}
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void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark)
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{
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struct vfsmount *mnt = mark->mnt;
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struct mount *m = real_mount(mnt);
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BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
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assert_spin_locked(&mark->lock);
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spin_lock(&mnt->mnt_root->d_lock);
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hlist_del_init_rcu(&mark->obj_list);
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mark->mnt = NULL;
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m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
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spin_unlock(&mnt->mnt_root->d_lock);
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}
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/*
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* given a group and vfsmount, find the mark associated with that combination.
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* if found take a reference to that mark and return it, else return NULL
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*/
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struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group,
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struct vfsmount *mnt)
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{
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struct mount *m = real_mount(mnt);
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struct fsnotify_mark *mark;
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spin_lock(&mnt->mnt_root->d_lock);
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mark = fsnotify_find_mark(&m->mnt_fsnotify_marks, group);
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spin_unlock(&mnt->mnt_root->d_lock);
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return mark;
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}
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/*
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* Attach an initialized mark to a given group and vfsmount.
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* These marks may be used for the fsnotify backend to determine which
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* event types should be delivered to which groups.
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*/
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int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
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struct fsnotify_group *group, struct vfsmount *mnt,
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int allow_dups)
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{
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struct mount *m = real_mount(mnt);
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int ret;
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mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;
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BUG_ON(!mutex_is_locked(&group->mark_mutex));
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assert_spin_locked(&mark->lock);
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spin_lock(&mnt->mnt_root->d_lock);
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mark->mnt = mnt;
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ret = fsnotify_add_mark_list(&m->mnt_fsnotify_marks, mark, allow_dups);
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m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
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spin_unlock(&mnt->mnt_root->d_lock);
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return ret;
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}
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