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08991e83b7
Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
112 lines
3.2 KiB
C
112 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/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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#include "../internal.h"
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void fsnotify_recalc_inode_mask(struct inode *inode)
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{
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fsnotify_recalc_mask(inode->i_fsnotify_marks);
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}
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/*
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* Given a group clear all of the inode marks associated with that group.
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*/
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void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
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{
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fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_OBJ_TYPE_INODE);
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}
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/*
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* given a group and inode, 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_inode_mark(struct fsnotify_group *group,
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struct inode *inode)
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{
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return fsnotify_find_mark(&inode->i_fsnotify_marks, group);
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}
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/**
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* fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
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* @sb: superblock being unmounted.
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*
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* Called during unmount with no locks held, so needs to be safe against
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* concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
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*/
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void fsnotify_unmount_inodes(struct super_block *sb)
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{
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struct inode *inode, *iput_inode = NULL;
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spin_lock(&sb->s_inode_list_lock);
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list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
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/*
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* We cannot __iget() an inode in state I_FREEING,
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* I_WILL_FREE, or I_NEW which is fine because by that point
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* the inode cannot have any associated watches.
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*/
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spin_lock(&inode->i_lock);
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if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
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spin_unlock(&inode->i_lock);
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continue;
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}
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/*
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* If i_count is zero, the inode cannot have any watches and
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* doing an __iget/iput with MS_ACTIVE clear would actually
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* evict all inodes with zero i_count from icache which is
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* unnecessarily violent and may in fact be illegal to do.
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*/
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if (!atomic_read(&inode->i_count)) {
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spin_unlock(&inode->i_lock);
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continue;
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}
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__iget(inode);
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spin_unlock(&inode->i_lock);
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spin_unlock(&sb->s_inode_list_lock);
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if (iput_inode)
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iput(iput_inode);
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/* for each watch, send FS_UNMOUNT and then remove it */
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fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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fsnotify_inode_delete(inode);
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iput_inode = inode;
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spin_lock(&sb->s_inode_list_lock);
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}
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spin_unlock(&sb->s_inode_list_lock);
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if (iput_inode)
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iput(iput_inode);
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}
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