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Commit e911d8af authored by Jan Kara's avatar Jan Kara
Browse files

fsnotify: Make fsnotify_mark_connector hold inode reference 



Currently inode reference is held by fsnotify marks. Change the rules so
that inode reference is held by fsnotify_mark_connector structure
whenever the list is non-empty. This simplifies the code and is more
logical.

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 86ffe245

fs/notify/fsnotify.h

+1 −3
Original line number Diff line number Diff line
@@ -21,8 +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);



extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,

						__u32 mask);

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

extern int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp,

				  struct fsnotify_mark *mark,
@@ -40,7 +38,7 @@ extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark, 
/* 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);

extern struct inode *fsnotify_destroy_inode_mark(struct fsnotify_mark *mark);

/* Find mark belonging to given group in the list of marks */

extern struct fsnotify_mark *fsnotify_find_mark(

					struct fsnotify_mark_connector *conn,

fs/notify/inode_mark.c

+5 −25
Original line number Diff line number Diff line
@@ -43,9 +43,10 @@ void fsnotify_recalc_inode_mask(struct inode *inode) 
	__fsnotify_update_child_dentry_flags(inode);

}



void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)

struct inode *fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)

{

	struct inode *inode = mark->connector->inode;

	bool empty;



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

	assert_spin_locked(&mark->lock);
@@ -53,6 +54,7 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark) 
	spin_lock(&inode->i_lock);



	hlist_del_init_rcu(&mark->obj_list);

	empty = hlist_empty(&mark->connector->list);

	mark->connector = NULL;



	/*
@@ -62,6 +64,8 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark) 
	 */

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

	spin_unlock(&inode->i_lock);



	return empty ? inode : NULL;

}



/*
@@ -88,30 +92,6 @@ struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group, 
	return mark;

}



/*

 * If we are setting a mark mask on an inode mark we should pin the inode

 * in memory.

 */

void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,

					 __u32 mask)

{

	struct inode *inode;



	assert_spin_locked(&mark->lock);



	if (mask && mark->connector &&

	    !(mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) {

		mark->flags |= FSNOTIFY_MARK_FLAG_OBJECT_PINNED;

		inode = igrab(mark->connector->inode);

		/*

		 * we shouldn't be able to get here if the inode wasn't

		 * already safely held in memory.  But bug in case it

		 * ever is wrong.

		 */

		BUG_ON(!inode);

	}

}



/*

 * Attach an initialized mark to a given inode.

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

fs/notify/mark.c

+6 −11
Original line number Diff line number Diff line
@@ -142,10 +142,9 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark) 


	mark->flags &= ~FSNOTIFY_MARK_FLAG_ATTACHED;



	if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE) {

		inode = mark->connector->inode;

		fsnotify_destroy_inode_mark(mark);

	} else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)

	if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE)

		inode = fsnotify_destroy_inode_mark(mark);

	else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)

		fsnotify_destroy_vfsmount_mark(mark);

	else

		BUG();
@@ -160,7 +159,7 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark) 


	spin_unlock(&mark->lock);



	if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED))

	if (inode)

		iput(inode);



	atomic_dec(&group->num_marks);
@@ -274,9 +273,6 @@ void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask) 
	assert_spin_locked(&mark->lock);



	mark->mask = mask;



	if (mark->connector && mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE)

		fsnotify_set_inode_mark_mask_locked(mark, mask);

}



void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mask)
@@ -375,6 +371,8 @@ int fsnotify_add_mark_list(struct fsnotify_mark_connector **connp, 
	/* is mark the first mark? */

	if (hlist_empty(&conn->list)) {

		hlist_add_head_rcu(&mark->obj_list, &conn->list);

		if (inode)

			__iget(inode);

		goto added;

	}
@@ -441,9 +439,6 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, 
	} else {

		BUG();

	}



	/* this will pin the object if appropriate */

	fsnotify_set_mark_mask_locked(mark, mark->mask);

	spin_unlock(&mark->lock);



	if (inode)

include/linux/fsnotify_backend.h

+6 −6
Original line number Diff line number Diff line
@@ -196,8 +196,9 @@ struct fsnotify_group { 


/*

 * Inode / vfsmount point to this structure which tracks all marks attached to

 * the inode / vfsmount. The structure is freed only when inode / vfsmount gets

 * freed.

 * the inode / vfsmount. The reference to inode / vfsmount is held by this

 * structure whenever the list is non-empty. The structure is freed only when

 * inode / vfsmount gets freed.

 */

struct fsnotify_mark_connector {

#define FSNOTIFY_OBJ_TYPE_INODE		0x01
@@ -245,10 +246,9 @@ struct fsnotify_mark { 
	struct fsnotify_mark_connector *connector;

	/* Events types to ignore [mark->lock, group->mark_mutex] */

	__u32 ignored_mask;

#define FSNOTIFY_MARK_FLAG_OBJECT_PINNED	0x04

#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY	0x08

#define FSNOTIFY_MARK_FLAG_ALIVE		0x10

#define FSNOTIFY_MARK_FLAG_ATTACHED		0x20

#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY	0x01

#define FSNOTIFY_MARK_FLAG_ALIVE		0x02

#define FSNOTIFY_MARK_FLAG_ATTACHED		0x04

	unsigned int flags;		/* flags [mark->lock] */

	void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */

};