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Commit 3427ce71 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Jan Kara
Browse files

fsnotify: clean up fsnotify() 



Use helpers to get first and next marks from connector.

Also get rid of inode_node/vfsmount_node local variables, which just refers
to the same objects as iter_info.  There was an srcu_dereference() for
foo_node, but that's completely superfluous since we've already done it
when obtaining foo_node.

Also get rid of inode_group/vfsmount_group local variables; checking
against non-NULL for these is the same as checking against non-NULL
inode_mark/vfsmount_mark.

Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent f37650f1

fs/notify/fsnotify.c

+45 −60
Original line number Diff line number Diff line
@@ -243,6 +243,29 @@ static int send_to_group(struct inode *to_tell, 
					file_name, cookie, iter_info);

}



static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)

{

	struct fsnotify_mark_connector *conn;

	struct hlist_node *node = NULL;



	conn = srcu_dereference(*connp, &fsnotify_mark_srcu);

	if (conn)

		node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);



	return hlist_entry_safe(node, struct fsnotify_mark, obj_list);

}



static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)

{

	struct hlist_node *node = NULL;



	if (mark)

		node = srcu_dereference(mark->obj_list.next,

					&fsnotify_mark_srcu);



	return hlist_entry_safe(node, struct fsnotify_mark, obj_list);

}



/*

 * 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
@@ -252,11 +275,7 @@ static int send_to_group(struct inode *to_tell, 
int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,

	     const unsigned char *file_name, u32 cookie)

{

	struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;

	struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;

	struct fsnotify_group *inode_group, *vfsmount_group;

	struct fsnotify_mark_connector *inode_conn, *vfsmount_conn;

	struct fsnotify_iter_info iter_info;

	struct fsnotify_iter_info iter_info = {};

	struct mount *mnt;

	int ret = 0;

	/* global tests shouldn't care about events on child only the specific event */
@@ -291,26 +310,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, 


	if ((mask & FS_MODIFY) ||

	    (test_mask & to_tell->i_fsnotify_mask)) {

		inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,

					      &fsnotify_mark_srcu);

		if (inode_conn)

			inode_node = srcu_dereference(inode_conn->list.first,

						      &fsnotify_mark_srcu);

		iter_info.inode_mark =

			fsnotify_first_mark(&to_tell->i_fsnotify_marks);

	}



	if (mnt && ((mask & FS_MODIFY) ||

		    (test_mask & mnt->mnt_fsnotify_mask))) {

		inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,

					      &fsnotify_mark_srcu);

		if (inode_conn)

			inode_node = srcu_dereference(inode_conn->list.first,

						      &fsnotify_mark_srcu);

		vfsmount_conn = srcu_dereference(mnt->mnt_fsnotify_marks,

					         &fsnotify_mark_srcu);

		if (vfsmount_conn)

			vfsmount_node = srcu_dereference(

						vfsmount_conn->list.first,

						&fsnotify_mark_srcu);

		iter_info.inode_mark =

			fsnotify_first_mark(&to_tell->i_fsnotify_marks);

		iter_info.vfsmount_mark =

			fsnotify_first_mark(&mnt->mnt_fsnotify_marks);

	}



	/*
@@ -318,42 +327,18 @@ 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 (inode_node || vfsmount_node) {

		inode_group = NULL;

		inode_mark = NULL;

		vfsmount_group = NULL;

		vfsmount_mark = NULL;



		if (inode_node) {

			inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),

						 struct fsnotify_mark, obj_list);

			inode_group = inode_mark->group;

		}



		if (vfsmount_node) {

			vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),

						    struct fsnotify_mark, obj_list);

			vfsmount_group = vfsmount_mark->group;

		}

		/*

		 * Need to protect both marks against freeing so that we can

		 * continue iteration from this place, regardless of which mark

		 * we actually happen to send an event for.

		 */

		iter_info.inode_mark = inode_mark;

		iter_info.vfsmount_mark = vfsmount_mark;



		if (inode_group && vfsmount_group) {

			int cmp = fsnotify_compare_groups(inode_group,

							  vfsmount_group);

			if (cmp > 0) {

				inode_group = NULL;

	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;



		if (inode_mark && vfsmount_mark) {

			int cmp = fsnotify_compare_groups(inode_mark->group,

							  vfsmount_mark->group);

			if (cmp > 0)

				inode_mark = NULL;

			} else if (cmp < 0) {

				vfsmount_group = NULL;

			else if (cmp < 0)

				vfsmount_mark = NULL;

		}

		}



		ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,

				    data, data_is, cookie, file_name,
@@ -362,12 +347,12 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, 
		if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))

			goto out;



		if (inode_group)

			inode_node = srcu_dereference(inode_node->next,

						      &fsnotify_mark_srcu);

		if (vfsmount_group)

			vfsmount_node = srcu_dereference(vfsmount_node->next,

							 &fsnotify_mark_srcu);

		if (inode_mark)

			iter_info.inode_mark =

				fsnotify_next_mark(iter_info.inode_mark);

		if (vfsmount_mark)

			iter_info.vfsmount_mark =

				fsnotify_next_mark(iter_info.vfsmount_mark);

	}

	ret = 0;

out: