Commit 0d48b7f0 authored by Eric Paris's avatar Eric Paris
Browse files

fsnotify: vfsmount marks generic functions



Much like inode-mark.c has all of the code dealing with marks on inodes
this patch adds a vfsmount-mark.c which has similar code but is intended
for marks on vfsmounts.
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent 2504c5d6
obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o \
mark.o
mark.o vfsmount_mark.o
obj-y += dnotify/
obj-y += inotify/
......
......@@ -24,6 +24,10 @@ extern void fsnotify_flush_notify(struct fsnotify_group *group);
extern int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct inode *inode,
int allow_dups);
/* add a mark to a vfsmount */
extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct vfsmount *mnt,
int allow_dups);
/* add a group to the inode group list */
extern void fsnotify_add_inode_group(struct fsnotify_group *group);
......@@ -32,6 +36,8 @@ extern void fsnotify_add_vfsmount_group(struct fsnotify_group *group);
/* final kfree of a group */
extern void fsnotify_final_destroy_group(struct fsnotify_group *group);
/* vfsmount specific destruction of a mark */
extern void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark);
/* inode specific destruction of a mark */
extern void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark);
/* run the list of all marks associated with inode and flag them to be freed */
......
......@@ -115,15 +115,11 @@ void fsnotify_put_mark(struct fsnotify_mark *mark)
void fsnotify_destroy_mark(struct fsnotify_mark *mark)
{
struct fsnotify_group *group;
struct inode *inode;
struct inode *inode = NULL;
spin_lock(&mark->lock);
group = mark->group;
inode = mark->i.inode;
BUG_ON(group && !inode);
BUG_ON(!group && inode);
/* if !group something else already marked this to die */
if (!group) {
......@@ -136,8 +132,11 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
spin_lock(&group->mark_lock);
if (mark->flags & FSNOTIFY_MARK_FLAG_INODE)
if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
fsnotify_destroy_inode_mark(mark);
inode = mark->i.inode;
} else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT)
fsnotify_destroy_vfsmount_mark(mark);
else
BUG();
......@@ -169,8 +168,8 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
* is just a lazy update (and could be a perf win...)
*/
iput(inode);
if (inode)
iput(inode);
/*
* it's possible that this group tried to destroy itself, but this
......@@ -192,7 +191,6 @@ int fsnotify_add_mark(struct fsnotify_mark *mark,
{
int ret = 0;
BUG_ON(mnt);
BUG_ON(inode && mnt);
BUG_ON(!inode && !mnt);
......@@ -223,6 +221,10 @@ int fsnotify_add_mark(struct fsnotify_mark *mark,
ret = fsnotify_add_inode_mark(mark, group, inode, allow_dups);
if (ret)
goto err;
} else if (mnt) {
ret = fsnotify_add_vfsmount_mark(mark, group, mnt, allow_dups);
if (ret)
goto err;
} else {
BUG();
}
......
/*
* 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/slab.h>
#include <linux/spinlock.h>
#include <linux/writeback.h> /* for inode_lock */
#include <asm/atomic.h>
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
{
struct fsnotify_mark *mark, *lmark;
struct hlist_node *pos, *n;
LIST_HEAD(free_list);
spin_lock(&mnt->mnt_root->d_lock);
hlist_for_each_entry_safe(mark, pos, n, &mnt->mnt_fsnotify_marks, m.m_list) {
list_add(&mark->m.free_m_list, &free_list);
hlist_del_init(&mark->m.m_list);
fsnotify_get_mark(mark);
}
spin_unlock(&mnt->mnt_root->d_lock);
list_for_each_entry_safe(mark, lmark, &free_list, m.free_m_list) {
fsnotify_destroy_mark(mark);
fsnotify_put_mark(mark);
}
}
/*
* Recalculate the mask of events relevant to a given vfsmount locked.
*/
static void fsnotify_recalc_vfsmount_mask_locked(struct vfsmount *mnt)
{
struct fsnotify_mark *mark;
struct hlist_node *pos;
__u32 new_mask = 0;
assert_spin_locked(&mnt->mnt_root->d_lock);
hlist_for_each_entry(mark, pos, &mnt->mnt_fsnotify_marks, m.m_list)
new_mask |= mark->mask;
mnt->mnt_fsnotify_mask = new_mask;
}
/*
* 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)
{
spin_lock(&mnt->mnt_root->d_lock);
fsnotify_recalc_vfsmount_mask_locked(mnt);
spin_unlock(&mnt->mnt_root->d_lock);
}
void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark)
{
struct vfsmount *mnt = mark->m.mnt;
assert_spin_locked(&mark->lock);
assert_spin_locked(&mark->group->mark_lock);
spin_lock(&mnt->mnt_root->d_lock);
hlist_del_init(&mark->m.m_list);
mark->m.mnt = NULL;
fsnotify_recalc_vfsmount_mask_locked(mnt);
spin_unlock(&mnt->mnt_root->d_lock);
}
static struct fsnotify_mark *fsnotify_find_vfsmount_mark_locked(struct fsnotify_group *group,
struct vfsmount *mnt)
{
struct fsnotify_mark *mark;
struct hlist_node *pos;
assert_spin_locked(&mnt->mnt_root->d_lock);
hlist_for_each_entry(mark, pos, &mnt->mnt_fsnotify_marks, m.m_list) {
if (mark->group == group) {
fsnotify_get_mark(mark);
return mark;
}
}
return NULL;
}
/*
* 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 fsnotify_mark *mark;
spin_lock(&mnt->mnt_root->d_lock);
mark = fsnotify_find_vfsmount_mark_locked(group, mnt);
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 fsnotify_mark *lmark = NULL;
int ret = 0;
mark->flags = FSNOTIFY_MARK_FLAG_VFSMOUNT;
/*
* LOCKING ORDER!!!!
* mark->lock
* group->mark_lock
* mnt->mnt_root->d_lock
*/
assert_spin_locked(&mark->lock);
assert_spin_locked(&group->mark_lock);
spin_lock(&mnt->mnt_root->d_lock);
if (!allow_dups)
lmark = fsnotify_find_vfsmount_mark_locked(group, mnt);
if (!lmark) {
mark->m.mnt = mnt;
hlist_add_head(&mark->m.m_list, &mnt->mnt_fsnotify_marks);
fsnotify_recalc_vfsmount_mask_locked(mnt);
} else {
ret = -EEXIST;
}
spin_unlock(&mnt->mnt_root->d_lock);
return ret;
}
......@@ -360,6 +360,8 @@ extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group
/* functions used to manipulate the marks attached to inodes */
/* run all marks associated with a vfsmount and update mnt->mnt_fsnotify_mask */
extern void fsnotify_recalc_vfsmount_mask(struct vfsmount *mnt);
/* run all marks associated with an inode and update inode->i_fsnotify_mask */
extern void fsnotify_recalc_inode_mask(struct inode *inode);
extern void fsnotify_init_mark(struct fsnotify_mark *mark, void (*free_mark)(struct fsnotify_mark *mark));
......
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