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Commit d9a6f30b authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

fsnotify: introduce marks iteration helpers 



Introduce helpers fsnotify_iter_select_report_types() and
fsnotify_iter_next() to abstract the inode/vfsmount marks merged
list iteration.

This is a preparation patch before generalizing mark list
iteration to more mark object types (i.e. super block marks).

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 5b0457ad

fs/notify/fsnotify.c

+49 −25
Original line number Diff line number Diff line
@@ -260,6 +260,53 @@ static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark) 
	return hlist_entry_safe(node, struct fsnotify_mark, obj_list);

}



/*

 * iter_info is a multi head priority queue of marks.

 * Pick a subset of marks from queue heads, all with the

 * same group and set the report_mask for selected subset.

 * Returns the report_mask of the selected subset.

 */

static unsigned int fsnotify_iter_select_report_types(

		struct fsnotify_iter_info *iter_info)

{

	struct fsnotify_mark *inode_mark = iter_info->inode_mark;

	struct fsnotify_mark *vfsmount_mark = iter_info->vfsmount_mark;

	int cmp;



	if (!inode_mark && !vfsmount_mark)

		return 0;



	if (inode_mark && vfsmount_mark) {

		cmp = fsnotify_compare_groups(inode_mark->group,

					      vfsmount_mark->group);

	} else {

		cmp = inode_mark ? -1 : 1;

	}



	iter_info->report_mask = 0;

	if (cmp <= 0)

		iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;

	if (cmp >= 0)

		iter_info->report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;



	return iter_info->report_mask;

}



/*

 * Pop from iter_info multi head queue, the marks that were iterated in the

 * current iteration step.

 */

static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)

{

	if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)

		iter_info->inode_mark =

			fsnotify_next_mark(iter_info->inode_mark);



	if (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)

		iter_info->vfsmount_mark =

			fsnotify_next_mark(iter_info->vfsmount_mark);

}



/*

 * This is the main call to fsnotify.  The VFS calls into hook specific functions

 * in linux/fsnotify.h.  Those functions then in turn call here.  Here will call
@@ -321,37 +368,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, 
	 * ignore masks are properly reflected for mount mark notifications.

	 * That's why this traversal is so complicated...

	 */

	while (iter_info.inode_mark || iter_info.vfsmount_mark) {

		struct fsnotify_mark *inode_mark = iter_info.inode_mark;

		struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark;

		int cmp;



		if (inode_mark && vfsmount_mark) {

			cmp = fsnotify_compare_groups(inode_mark->group,

						      vfsmount_mark->group);

		} else {

			cmp = inode_mark ? -1 : 1;

		}



		iter_info.report_mask = 0;

		if (cmp <= 0)

			iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_INODE_FL;

		if (cmp >= 0)

			iter_info.report_mask |= FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL;



	while (fsnotify_iter_select_report_types(&iter_info)) {

		ret = send_to_group(to_tell, mask, data, data_is, cookie,

				    file_name, &iter_info);



		if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))

			goto out;



		if (iter_info.report_mask & FSNOTIFY_OBJ_TYPE_INODE_FL)

			iter_info.inode_mark =

				fsnotify_next_mark(iter_info.inode_mark);



		if (iter_info.report_mask & FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL)

			iter_info.vfsmount_mark =

				fsnotify_next_mark(iter_info.vfsmount_mark);

		fsnotify_iter_next(&iter_info);

	}

	ret = 0;

out: