Commit 755b5bc6 authored by Jan Kara's avatar Jan Kara
Browse files

fsnotify: Remove indirection from mark list addition 



Adding notification mark to object list has been currently done through
fsnotify_add_{inode|vfsmount}_mark() helpers from
fsnotify_add_mark_locked() which call fsnotify_add_mark_list(). Remove
this unnecessary indirection to simplify the code.

Pushing all the locking to fsnotify_add_mark_list() also allows us to
allocate the connector structure with GFP_KERNEL mode.

Reviewed-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent e911d8af

fs/notify/fsnotify.h

+0 −14
Original line number Diff line number Diff line
@@ -21,20 +21,6 @@ extern u32 fsnotify_recalc_mask(struct fsnotify_mark_connector *conn); 
extern int fsnotify_compare_groups(struct fsnotify_group *a,

				   struct fsnotify_group *b);



/* Add mark to a proper place in mark list */

extern int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp,

				  struct fsnotify_mark *mark,

				  struct inode *inode, struct vfsmount *mnt,

				  int allow_dups);

/* add a mark to an inode */

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);



/* vfsmount specific destruction of a mark */

extern void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark);

/* inode specific destruction of a mark */

fs/notify/inode_mark.c

+0 −25
Original line number Diff line number Diff line
@@ -92,31 +92,6 @@ struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group, 
	return mark;

}



/*

 * 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.  These

 * marks are ordered according to priority, highest number first, and then by

 * 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)

{

	int ret;



	BUG_ON(!mutex_is_locked(&group->mark_mutex));

	assert_spin_locked(&mark->lock);



	spin_lock(&inode->i_lock);

	ret = fsnotify_add_mark_list(&inode->i_fsnotify_marks, mark, inode,

				     NULL, allow_dups);

	inode->i_fsnotify_mask = fsnotify_recalc_mask(inode->i_fsnotify_marks);

	spin_unlock(&inode->i_lock);



	return ret;

}



/**

 * fsnotify_unmount_inodes - an sb is unmounting.  handle any watched inodes.

 * @sb: superblock being unmounted.

fs/notify/mark.c

+43 −23
Original line number Diff line number Diff line
@@ -320,12 +320,13 @@ int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b) 


static int fsnotify_attach_connector_to_object(

					struct fsnotify_mark_connector **connp,

					spinlock_t *lock,

					struct inode *inode,

					struct vfsmount *mnt)

{

	struct fsnotify_mark_connector *conn;



	conn = kmem_cache_alloc(fsnotify_mark_connector_cachep, GFP_ATOMIC);

	conn = kmem_cache_alloc(fsnotify_mark_connector_cachep, GFP_KERNEL);

	if (!conn)

		return -ENOMEM;

	INIT_HLIST_HEAD(&conn->list);
@@ -341,7 +342,12 @@ static int fsnotify_attach_connector_to_object( 
	 * lockless_dereference() in fsnotify().

	 */

	smp_wmb();

	spin_lock(lock);

	if (!*connp)

		*connp = conn;

	else

		kmem_cache_free(fsnotify_mark_connector_cachep, conn);

	spin_unlock(lock);



	return 0;

}
@@ -352,20 +358,35 @@ static int fsnotify_attach_connector_to_object( 
 * to which group and for which inodes. These marks are ordered according to

 * priority, highest number first, and then by the group's location in memory.

 */

int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp,

			   struct fsnotify_mark *mark, struct inode *inode,

			   struct vfsmount *mnt, int allow_dups)

static int fsnotify_add_mark_list(struct fsnotify_mark *mark,

				  struct inode *inode, struct vfsmount *mnt,

				  int allow_dups)

{

	struct fsnotify_mark *lmark, *last = NULL;

	struct fsnotify_mark_connector *conn;

	struct fsnotify_mark_connector **connp;

	spinlock_t *lock;

	int cmp;

	int err;

	int err = 0;



	if (WARN_ON(!inode && !mnt))

		return -EINVAL;

	if (inode) {

		connp = &inode->i_fsnotify_marks;

		lock = &inode->i_lock;

	} else {

		connp = &real_mount(mnt)->mnt_fsnotify_marks;

		lock = &mnt->mnt_root->d_lock;

	}



	if (!*connp) {

		err = fsnotify_attach_connector_to_object(connp, inode, mnt);

		err = fsnotify_attach_connector_to_object(connp, lock,

							  inode, mnt);

		if (err)

			return err;

	}

	spin_lock(&mark->lock);

	spin_lock(lock);

	conn = *connp;



	/* is mark the first mark? */
@@ -380,8 +401,10 @@ int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp, 
	hlist_for_each_entry(lmark, &conn->list, obj_list) {

		last = lmark;



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

			return -EEXIST;

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

			err = -EEXIST;

			goto out_err;

		}



		cmp = fsnotify_compare_groups(lmark->group, mark->group);

		if (cmp >= 0) {
@@ -395,7 +418,10 @@ int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp, 
	hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);

added:

	mark->connector = conn;

	return 0;

out_err:

	spin_unlock(lock);

	spin_unlock(&mark->lock);

	return err;

}



/*
@@ -427,22 +453,16 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, 
	list_add(&mark->g_list, &group->marks_list);

	atomic_inc(&group->num_marks);

	fsnotify_get_mark(mark); /* for i_list and g_list */

	spin_unlock(&mark->lock);



	if (inode) {

		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);

	ret = fsnotify_add_mark_list(mark, inode, mnt, allow_dups);

	if (ret)

		goto err;

	} else {

		BUG();

	}

	spin_unlock(&mark->lock);



	if (inode)

		__fsnotify_update_child_dentry_flags(inode);

		fsnotify_recalc_inode_mask(inode);

	else

		fsnotify_recalc_vfsmount_mask(mnt);



	return ret;

err:

fs/notify/vfsmount_mark.c

+0 −24
Original line number Diff line number Diff line
@@ -80,27 +80,3 @@ struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group, 


	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;



	BUG_ON(!mutex_is_locked(&group->mark_mutex));

	assert_spin_locked(&mark->lock);



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

	ret = fsnotify_add_mark_list(&m->mnt_fsnotify_marks, mark, NULL, mnt,

				     allow_dups);

	m->mnt_fsnotify_mask = fsnotify_recalc_mask(m->mnt_fsnotify_marks);

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



	return ret;

}

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