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Commit 0c6532e4 authored by Eric Paris's avatar Eric Paris
Browse files

fsnotify: place marks on object in order of group memory address 



fsnotify_marks currently are placed on objects (inodes or vfsmounts) in
arbitrary order.  This patch places them in order of the group memory address.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent c1e5c954

fs/notify/inode_mark.c

+29 −11
Original line number Diff line number Diff line
@@ -174,15 +174,17 @@ void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark, 
}



/*

 * Attach an initialized mark to a given group and inode.

 * Attach an initialized mark to a given inode.

 * These marks may be used for the fsnotify backend to determine which

 * event types should be delivered to which group and for which inodes.

 * event types should be delivered to which group and for which inodes.  These

 * marks are ordered according to the group's location in memory.

 */

int fsnotify_add_inode_mark(struct fsnotify_mark *mark,

			    struct fsnotify_group *group, struct inode *inode,

			    int allow_dups)

{

	struct fsnotify_mark *lmark = NULL;

	struct fsnotify_mark *lmark;

	struct hlist_node *node, *last = NULL;

	int ret = 0;



	mark->flags = FSNOTIFY_MARK_FLAG_INODE;
@@ -192,20 +194,36 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark, 


	spin_lock(&inode->i_lock);



	if (!allow_dups)

		lmark = fsnotify_find_inode_mark_locked(group, inode);

	if (!lmark) {

	mark->i.inode = inode;



	/* is mark the first mark? */

	if (hlist_empty(&inode->i_fsnotify_marks)) {

		hlist_add_head(&mark->i.i_list, &inode->i_fsnotify_marks);



		fsnotify_recalc_inode_mask_locked(inode);

		goto out;

	}



	spin_unlock(&inode->i_lock);

	/* should mark be in the middle of the current list? */

	hlist_for_each_entry(lmark, node, &inode->i_fsnotify_marks, i.i_list) {

		last = node;



	if (lmark)

		if ((lmark->group == group) && !allow_dups) {

			ret = -EEXIST;

			goto out;

		}



		if (mark->group < lmark->group)

			continue;



		hlist_add_before(&mark->i.i_list, &lmark->i.i_list);

		goto out;

	}



	BUG_ON(last == NULL);

	/* mark should be the last entry.  last is the current last entry */

	hlist_add_after(last, &mark->i.i_list);

out:

	fsnotify_recalc_inode_mask_locked(inode);

	spin_unlock(&inode->i_lock);



	return ret;

}

fs/notify/vfsmount_mark.c

+26 −14
Original line number Diff line number Diff line
@@ -141,34 +141,46 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark, 
			       struct fsnotify_group *group, struct vfsmount *mnt,

			       int allow_dups)

{

	struct fsnotify_mark *lmark = NULL;

	struct fsnotify_mark *lmark;

	struct hlist_node *node, *last = 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;



	/* is mark the first mark? */

	if (hlist_empty(&mnt->mnt_fsnotify_marks)) {

		hlist_add_head(&mark->m.m_list, &mnt->mnt_fsnotify_marks);

		goto out;

	}



		fsnotify_recalc_vfsmount_mask_locked(mnt);

	} else {

	/* should mark be in the middle of the current list? */

	hlist_for_each_entry(lmark, node, &mnt->mnt_fsnotify_marks, m.m_list) {

		last = node;



		if ((lmark->group == group) && !allow_dups) {

			ret = -EEXIST;

			goto out;

		}



		if (mark->group < lmark->group)

			continue;



		hlist_add_before(&mark->m.m_list, &lmark->m.m_list);

		goto out;

	}



	BUG_ON(last == NULL);

	/* mark should be the last entry.  last is the current last entry */

	hlist_add_after(last, &mark->m.m_list);

out:

	fsnotify_recalc_vfsmount_mask_locked(mnt);

	spin_unlock(&mnt->mnt_root->d_lock);



	return ret;