Commit aff12041 authored by Horst Birthelmer's avatar Horst Birthelmer Committed by Miklos Szeredi
Browse files

fuse: fix inode initialization race 



Fix a race between fuse_iget() and fuse_reverse_inval_inode() where
invalidation can arrive while an inode is being initialized, causing
the invalidation to be lost.
By keeping the inode state I_NEW as long as the attributes are not valid
the invalidation can wait until the inode is fully initialized.

Suggested-by: default avatarJoanne Koong <joannelkoong@gmail.com>
Signed-off-by: default avatarHorst Birthelmer <hbirthelmer@ddn.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 204aa22a

fs/fuse/inode.c

+5 −2
Original line number Diff line number Diff line
@@ -470,6 +470,7 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 
	struct inode *inode;

	struct fuse_inode *fi;

	struct fuse_conn *fc = get_fuse_conn_super(sb);

	bool is_new_inode = false;



	/*

	 * Auto mount points get their node id from the submount root, which is
@@ -505,13 +506,13 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 
	if (!inode)

		return NULL;



	if ((inode_state_read_once(inode) & I_NEW)) {

	is_new_inode = inode_state_read_once(inode) & I_NEW;

	if (is_new_inode) {

		inode->i_flags |= S_NOATIME;

		if (!fc->writeback_cache || !S_ISREG(attr->mode))

			inode->i_flags |= S_NOCMTIME;

		inode->i_generation = generation;

		fuse_init_inode(inode, attr, fc);

		unlock_new_inode(inode);

	} else if (fuse_stale_inode(inode, generation, attr)) {

		/* nodeid was reused, any I/O on the old inode should fail */

		fuse_make_bad(inode);
@@ -528,6 +529,8 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 
done:

	fuse_change_attributes_i(inode, attr, NULL, attr_valid, attr_version,

				 evict_ctr);

	if (is_new_inode)

		unlock_new_inode(inode);

	return inode;

}