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From: Daniel Rosenberg <drosen@google.com>
To: Miklos Szeredi <miklos@szeredi.hu>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	John Fastabend <john.fastabend@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
	KP Singh <kpsingh@kernel.org>,
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>,
	Daniel Rosenberg <drosen@google.com>,
	Paul Lawrence <paullawrence@google.com>,
	Alessio Balsini <balsini@google.com>,
	David Anderson <dvander@google.com>,
	Sandeep Patil <sspatil@google.com>,
	linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org,
	kernel-team@android.com
Subject: [PATCH 16/26] fuse-bpf: support FUSE_READDIR
Date: Mon, 26 Sep 2022 16:18:12 -0700	[thread overview]
Message-ID: <20220926231822.994383-17-drosen@google.com> (raw)
In-Reply-To: <20220926231822.994383-1-drosen@google.com>

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
 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 {
-- 
2.37.3.998.g577e59143f-goog


  parent reply	other threads:[~2022-09-26 23:20 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-26 23:17 [PATCH 00/26] FUSE BPF: A Stacked Filesystem Extension for FUSE Daniel Rosenberg
2022-09-26 23:17 ` [PATCH 01/26] bpf: verifier: Allow for multiple packets Daniel Rosenberg
2022-09-26 23:17 ` [PATCH 02/26] bpf: verifier: Allow single packet invalidation Daniel Rosenberg
2022-09-26 23:17 ` [PATCH 03/26] fuse-bpf: Update uapi for fuse-bpf Daniel Rosenberg
2022-09-27 18:19   ` Miklos Szeredi
2022-09-30 22:02     ` Paul Lawrence
2022-10-01  7:47       ` Amir Goldstein
2022-09-26 23:18 ` [PATCH 04/26] fuse-bpf: Add BPF supporting functions Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 05/26] fs: Generic function to convert iocb to rw flags Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 06/26] bpf: Export bpf_prog_fops Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 07/26] fuse-bpf: Prepare for fuse-bpf patch Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 08/26] fuse: Add fuse-bpf, a stacked fs extension for FUSE Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 09/26] fuse-bpf: Don't support export_operations Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 10/26] fuse-bpf: Partially add mapping support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 11/26] fuse-bpf: Add lseek support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 12/26] fuse-bpf: Add support for fallocate Daniel Rosenberg
2022-09-27 22:07   ` Dave Chinner
2022-09-27 23:36     ` Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 13/26] fuse-bpf: Support file/dir open/close Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 14/26] fuse-bpf: Support mknod/unlink/mkdir/rmdir Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 15/26] fuse-bpf: Add support for read/write iter Daniel Rosenberg
2022-10-01  6:53   ` Amir Goldstein
2022-09-26 23:18 ` Daniel Rosenberg [this message]
2022-09-26 23:18 ` [PATCH 17/26] fuse-bpf: Add support for sync operations Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 18/26] fuse-bpf: Add Rename support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 19/26] fuse-bpf: Add attr support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 20/26] fuse-bpf: Add support for FUSE_COPY_FILE_RANGE Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 21/26] fuse-bpf: Add xattr support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 22/26] fuse-bpf: Add symlink/link support Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 23/26] fuse-bpf: allow mounting with no userspace daemon Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 24/26] fuse-bpf: Call bpf for pre/post filters Daniel Rosenberg
2022-09-26 23:18 ` [PATCH 25/26] fuse-bpf: Add userspace " Daniel Rosenberg
2022-09-28  6:41 ` [PATCH 00/26] FUSE BPF: A Stacked Filesystem Extension for FUSE Martin KaFai Lau
2022-09-28 12:31   ` Brian Foster
2022-10-01  0:47     ` Daniel Rosenberg
2022-10-01  0:05   ` Daniel Rosenberg
2022-10-01  0:24     ` Alexei Starovoitov
2022-10-06  1:58     ` Martin KaFai Lau

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