From patchwork Mon Sep 26 23:18:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Rosenberg X-Patchwork-Id: 12989543 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F698C32771 for ; Mon, 26 Sep 2022 23:20:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230495AbiIZXUn (ORCPT ); Mon, 26 Sep 2022 19:20:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230523AbiIZXTR (ORCPT ); Mon, 26 Sep 2022 19:19:17 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB7D3D1EBD for ; Mon, 26 Sep 2022 16:19:12 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id n6-20020a5b0486000000b006aff8dc9865so7078876ybp.11 for ; Mon, 26 Sep 2022 16:19:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date; bh=4aH9WjQOeQQx2PJx5YUK/k9FfDLlxDnoz2TckhpfaO8=; b=owJtIFFajyoIIzra3aBaBUn0U8VES46+dTIZYx3WvH4q1sD68GlGUOH78paFBToAjz hka1LoouNb3ejladAjidizXbJmp0sJ7oMrRq8F7plJi9efDspgdtHjxCvsZTXlBdgyl0 3sQ84XxkNc/BKtpaMCpn/ekmseu7leDNvb572pvHFXR53NWRSEOKlQDkQwecSwr874fF B9u/TNQrnaBbcyVg7vXpMiz72HFWnbSGzUYRsqa7K7a7wVLM4yah9NwHi8XW4Z7YJaV4 28WRpWqewbGR5XrzIGQpLYENmhpluQPf9uxPMfPtOutkWPPGb4+q5F5PC8h3YFgHfydF Ss1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date; bh=4aH9WjQOeQQx2PJx5YUK/k9FfDLlxDnoz2TckhpfaO8=; b=xHng+Sr3hOaHV4J35M0vYRN3YrdvsXeQlKpgdEZ2etYM1IQ48/RgHmwrFCUtpVSEVE WMMfSscUhxN72SSwCLP7soEdaQtQSE+dM6A2ait9Fxwx8VrIXgiPy7k8wU3XwHKBmQyP pmruubYBK1AOdBzsVcpCCs2MUpl7kjjjyOOg/elZw6JLWhM2MxBKcZtdT9HBDW2dX5h7 Acyeqwvl0fPH13Dwat8Qj5j27FaARpokPkbFtf+XQexebCjblNxPyGzpGRJACtqY/Etf nF49YWjLrDSiPqLI+E+Bjq4t+ijQEhESH+btnVS5gv04FiVNPsk4rutgsNge9LgChs6E Mf7g== X-Gm-Message-State: ACrzQf0nOt7bHuiJPdOUZlcxeahdgd7vlm+ibHmC358GKK7Y9Mnwivsi 11Vk9wpi2zdBctuj2vNE8OhW/QebJVo= X-Google-Smtp-Source: AMsMyM6gCp5D5lZ+hYmr0RklbZNK5kjwwuChTXIjTFC5duGJMseZMT5jOSiRIselwHmo6GNwDw+9eveQL4g= X-Received: from drosen.mtv.corp.google.com ([2620:15c:211:200:4643:a68e:2b7:f873]) (user=drosen job=sendgmr) by 2002:a81:3985:0:b0:350:7c64:cfcc with SMTP id g127-20020a813985000000b003507c64cfccmr15428496ywa.226.1664234352106; Mon, 26 Sep 2022 16:19:12 -0700 (PDT) Date: Mon, 26 Sep 2022 16:18:12 -0700 In-Reply-To: <20220926231822.994383-1-drosen@google.com> Mime-Version: 1.0 References: <20220926231822.994383-1-drosen@google.com> X-Mailer: git-send-email 2.37.3.998.g577e59143f-goog Message-ID: <20220926231822.994383-17-drosen@google.com> Subject: [PATCH 16/26] fuse-bpf: support FUSE_READDIR From: Daniel Rosenberg To: Miklos Szeredi , Alexei Starovoitov , Daniel Borkmann , John Fastabend Cc: Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Daniel Rosenberg , Paul Lawrence , Alessio Balsini , David Anderson , Sandeep Patil , linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, kernel-team@android.com Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Signed-off-by: Daniel Rosenberg Signed-off-by: Paul Lawrence --- fs/fuse/backing.c | 162 ++++++++++++++++++++++++++++++++++++++ fs/fuse/fuse_i.h | 18 +++++ fs/fuse/readdir.c | 22 ++++++ include/uapi/linux/fuse.h | 6 ++ 4 files changed, 208 insertions(+) diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c index cf4ad9f4fe10..a31199064dc7 100644 --- a/fs/fuse/backing.c +++ b/fs/fuse/backing.c @@ -1312,6 +1312,168 @@ int fuse_unlink_finalize(struct bpf_fuse_args *fa, int *out, return 0; } +int fuse_readdir_initialize_in(struct bpf_fuse_args *fa, struct fuse_read_io *frio, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued) +{ + struct fuse_file *ff = file->private_data; + + *fa = (struct bpf_fuse_args) { + .nodeid = ff->nodeid, + .opcode = FUSE_READDIR, + .in_numargs = 1, + .in_args[0] = (struct bpf_fuse_arg) { + .size = sizeof(frio->fri), + .value = &frio->fri, + }, + }; + + frio->fri = (struct fuse_read_in) { + .fh = ff->fh, + .offset = ctx->pos, + .size = PAGE_SIZE, + }; + + *force_again = false; + *allow_force = true; + return 0; +} + +int fuse_readdir_initialize_out(struct bpf_fuse_args *fa, struct fuse_read_io *frio, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued) +{ + u8 *page = (u8 *)__get_free_page(GFP_KERNEL); + + if (!page) + return -ENOMEM; + + fa->flags = FUSE_BPF_OUT_ARGVAR; + fa->out_numargs = 2; + fa->out_args[0] = (struct bpf_fuse_arg) { + .size = sizeof(frio->fro), + .value = &frio->fro, + }; + fa->out_args[1] = (struct bpf_fuse_arg) { + .size = PAGE_SIZE, + .max_size = PAGE_SIZE, + .flags = BPF_FUSE_VARIABLE_SIZE, + .value = page, + }; + frio->fro = (struct fuse_read_out) { + .again = 0, + .offset = 0, + }; + + return 0; +} + +struct extfuse_ctx { + struct dir_context ctx; + u8 *addr; + size_t offset; +}; + +static int filldir(struct dir_context *ctx, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + struct extfuse_ctx *ec = container_of(ctx, struct extfuse_ctx, ctx); + struct fuse_dirent *fd = (struct fuse_dirent *)(ec->addr + ec->offset); + + if (ec->offset + sizeof(struct fuse_dirent) + namelen > PAGE_SIZE) + return -ENOMEM; + + *fd = (struct fuse_dirent) { + .ino = ino, + .off = offset, + .namelen = namelen, + .type = d_type, + }; + + memcpy(fd->name, name, namelen); + ec->offset += FUSE_DIRENT_SIZE(fd); + + return 0; +} + +static int parse_dirfile(char *buf, size_t nbytes, struct dir_context *ctx) +{ + while (nbytes >= FUSE_NAME_OFFSET) { + struct fuse_dirent *dirent = (struct fuse_dirent *) buf; + size_t reclen = FUSE_DIRENT_SIZE(dirent); + + if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) + return -EIO; + if (reclen > nbytes) + break; + if (memchr(dirent->name, '/', dirent->namelen) != NULL) + return -EIO; + + ctx->pos = dirent->off; + if (!dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino, + dirent->type)) + break; + + buf += reclen; + nbytes -= reclen; + } + + return 0; +} + + +int fuse_readdir_backing(struct bpf_fuse_args *fa, int *out, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued) +{ + struct fuse_file *ff = file->private_data; + struct file *backing_dir = ff->backing_file; + struct fuse_read_out *fro = fa->out_args[0].value; + struct extfuse_ctx ec; + + ec = (struct extfuse_ctx) { + .ctx.actor = filldir, + .ctx.pos = ctx->pos, + .addr = fa->out_args[1].value, + }; + + if (!ec.addr) + return -ENOMEM; + + if (!is_continued) + backing_dir->f_pos = file->f_pos; + + *out = iterate_dir(backing_dir, &ec.ctx); + if (ec.offset == 0) + *allow_force = false; + fa->out_args[1].size = ec.offset; + + fro->offset = ec.ctx.pos; + fro->again = false; + + return *out; +} + +int fuse_readdir_finalize(struct bpf_fuse_args *fa, int *out, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued) +{ + struct fuse_read_out *fro = fa->out_args[0].value; + struct fuse_file *ff = file->private_data; + struct file *backing_dir = ff->backing_file; + + *out = parse_dirfile(fa->out_args[1].value, fa->out_args[1].size, ctx); + *force_again = !!fro->again; + if (*force_again && !*allow_force) + *out = -EINVAL; + + ctx->pos = fro->offset; + backing_dir->f_pos = fro->offset; + + free_page((unsigned long)fa->out_args[1].value); + return *out; +} + int fuse_access_initialize_in(struct bpf_fuse_args *fa, struct fuse_access_in *fai, struct inode *inode, int mask) { diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index f427a7bb367c..8780a50be244 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1572,6 +1572,24 @@ int fuse_lookup_finalize(struct bpf_fuse_args *fa, struct dentry **out, struct inode *dir, struct dentry *entry, unsigned int flags); int fuse_revalidate_backing(struct dentry *entry, unsigned int flags); +struct fuse_read_io { + struct fuse_read_in fri; + struct fuse_read_out fro; +}; + +int fuse_readdir_initialize_in(struct bpf_fuse_args *fa, struct fuse_read_io *frio, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued); +int fuse_readdir_initialize_out(struct bpf_fuse_args *fa, struct fuse_read_io *frio, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued); +int fuse_readdir_backing(struct bpf_fuse_args *fa, int *out, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued); +int fuse_readdir_finalize(struct bpf_fuse_args *fa, int *out, + struct file *file, struct dir_context *ctx, + bool *force_again, bool *allow_force, bool is_continued); + int fuse_access_initialize_in(struct bpf_fuse_args *fa, struct fuse_access_in *fai, struct inode *inode, int mask); int fuse_access_initialize_out(struct bpf_fuse_args *fa, struct fuse_access_in *fai, diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c index b4e565711045..07da8570e337 100644 --- a/fs/fuse/readdir.c +++ b/fs/fuse/readdir.c @@ -20,6 +20,8 @@ static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) if (!fc->do_readdirplus) return false; + if (fi->nodeid == 0) + return false; if (!fc->readdirplus_auto) return true; if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) @@ -571,6 +573,26 @@ int fuse_readdir(struct file *file, struct dir_context *ctx) struct inode *inode = file_inode(file); int err; +#ifdef CONFIG_FUSE_BPF + bool bpf_ret = false; + bool allow_force; + bool force_again = false; + bool is_continued = false; + +again: + bpf_ret = fuse_bpf_backing(inode, struct fuse_read_io, err, + fuse_readdir_initialize_in, fuse_readdir_initialize_out, + fuse_readdir_backing, fuse_readdir_finalize, + file, ctx, &force_again, &allow_force, is_continued); + if (force_again && err >= 0) { + is_continued = true; + goto again; + } + + if (bpf_ret) + return err; +#endif + if (fuse_is_bad(inode)) return -EIO; diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 8c80c146e69b..b7736cb4bdaf 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -701,6 +701,12 @@ struct fuse_read_in { uint32_t padding; }; +struct fuse_read_out { + uint64_t offset; + uint32_t again; + uint32_t padding; +}; + #define FUSE_COMPAT_WRITE_IN_SIZE 24 struct fuse_write_in {