Re: [PATCH 4/6] fuse: return correct dentry for ->mkdir

From: Al Viro
Date: Fri Feb 21 2025 - 23:24:26 EST


On Fri, Feb 21, 2025 at 10:36:33AM +1100, NeilBrown wrote:

> @@ -871,7 +870,12 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
> args.in_args[0].value = &inarg;
> args.in_args[1].size = entry->d_name.len + 1;
> args.in_args[1].value = entry->d_name.name;
> - return create_new_entry(idmap, fm, &args, dir, entry, mode);
> + de = create_new_entry(idmap, fm, &args, dir, entry, mode);
> + if (IS_ERR(de))
> + return PTR_ERR(de);
> + if (de)
> + dput(de);
> + return 0;

Can that really happen?

> @@ -934,7 +939,12 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
> args.in_args[1].value = entry->d_name.name;
> args.in_args[2].size = len;
> args.in_args[2].value = link;
> - return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> + de = create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> + if (IS_ERR(de))
> + return PTR_ERR(de);
> + if (de)
> + dput(de);
> + return 0;

Same question.

> + de = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
> + if (!IS_ERR(de)) {
> + if (de)
> + dput(de);
> + de = NULL;

Whoa... Details, please. What's going on here?