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 22/26] fuse-bpf: Add symlink/link support
Date: Mon, 26 Sep 2022 16:18:18 -0700 [thread overview]
Message-ID: <20220926231822.994383-23-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 | 251 ++++++++++++++++++++++++++++++++++++++++++++++
fs/fuse/dir.c | 31 ++++++
fs/fuse/fuse_i.h | 33 ++++++
3 files changed, 315 insertions(+)
diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c
index d8c86234f253..485b6f1e8503 100644
--- a/fs/fuse/backing.c
+++ b/fs/fuse/backing.c
@@ -1951,6 +1951,97 @@ int fuse_unlink_finalize(struct bpf_fuse_args *fa, int *out,
return 0;
}
+int fuse_link_initialize_in(struct bpf_fuse_args *fa, struct fuse_link_in *fli,
+ struct dentry *entry, struct inode *dir,
+ struct dentry *newent)
+{
+ struct inode *src_inode = entry->d_inode;
+
+ *fli = (struct fuse_link_in) {
+ .oldnodeid = get_node_id(src_inode),
+ };
+
+ fa->opcode = FUSE_LINK;
+ fa->in_numargs = 2;
+ fa->in_args[0].size = sizeof(*fli);
+ fa->in_args[0].value = fli;
+ fa->in_args[1].size = newent->d_name.len + 1;
+ fa->in_args[1].max_size = NAME_MAX + 1;
+ fa->in_args[1].value = (void *) newent->d_name.name;
+ fa->in_args[1].flags = BPF_FUSE_VARIABLE_SIZE | BPF_FUSE_MUST_ALLOCATE;
+
+ return 0;
+}
+
+int fuse_link_initialize_out(struct bpf_fuse_args *fa, struct fuse_link_in *fli,
+ struct dentry *entry, struct inode *dir,
+ struct dentry *newent)
+{
+ return 0;
+}
+
+int fuse_link_backing(struct bpf_fuse_args *fa, int *out, struct dentry *entry,
+ struct inode *dir, struct dentry *newent)
+{
+ struct path backing_old_path;
+ struct path backing_new_path;
+ struct dentry *backing_dir_dentry;
+ struct inode *fuse_new_inode = NULL;
+ struct fuse_inode *fuse_dir_inode = get_fuse_inode(dir);
+ struct inode *backing_dir_inode = fuse_dir_inode->backing_inode;
+
+ *out = 0;
+ get_fuse_backing_path(entry, &backing_old_path);
+ if (!backing_old_path.dentry)
+ return -EBADF;
+
+ get_fuse_backing_path(newent, &backing_new_path);
+ if (!backing_new_path.dentry) {
+ *out = -EBADF;
+ goto err_dst_path;
+ }
+
+ backing_dir_dentry = dget_parent(backing_new_path.dentry);
+ backing_dir_inode = d_inode(backing_dir_dentry);
+
+ inode_lock_nested(backing_dir_inode, I_MUTEX_PARENT);
+ *out = vfs_link(backing_old_path.dentry, &init_user_ns,
+ backing_dir_inode, backing_new_path.dentry, NULL);
+ inode_unlock(backing_dir_inode);
+ if (*out)
+ goto out;
+
+ if (d_really_is_negative(backing_new_path.dentry) ||
+ unlikely(d_unhashed(backing_new_path.dentry))) {
+ *out = -EINVAL;
+ /**
+ * TODO: overlayfs responds to this situation with a
+ * lookupOneLen. Should we do that too?
+ */
+ goto out;
+ }
+
+ fuse_new_inode = fuse_iget_backing(dir->i_sb, fuse_dir_inode->nodeid, backing_dir_inode);
+ if (IS_ERR(fuse_new_inode)) {
+ *out = PTR_ERR(fuse_new_inode);
+ goto out;
+ }
+ d_instantiate(newent, fuse_new_inode);
+
+out:
+ dput(backing_dir_dentry);
+ path_put(&backing_new_path);
+err_dst_path:
+ path_put(&backing_old_path);
+ return *out;
+}
+
+int fuse_link_finalize(struct bpf_fuse_args *fa, int *out, struct dentry *entry,
+ struct inode *dir, struct dentry *newent)
+{
+ return 0;
+}
+
int fuse_getattr_initialize_in(struct bpf_fuse_args *fa, struct fuse_getattr_io *fgio,
const struct dentry *entry, struct kstat *stat,
u32 request_mask, unsigned int flags)
@@ -2215,6 +2306,166 @@ int fuse_statfs_finalize(struct bpf_fuse_args *fa, int *out,
return 0;
}
+int fuse_get_link_initialize_in(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback)
+{
+ /*
+ * TODO
+ * If we want to handle changing these things, we'll need to copy
+ * the lower fs's data into our own buffer, and provide our own callback
+ * to free that buffer.
+ *
+ * Pre could change the name we're looking at
+ * postfilter can change the name we return
+ *
+ * We ought to only make that buffer if it's been requested, so leaving
+ * this unimplemented for the moment
+ */
+ *fa = (struct bpf_fuse_args) {
+ .opcode = FUSE_READLINK,
+ .nodeid = get_node_id(inode),
+ .in_numargs = 1,
+ .in_args[0] = (struct bpf_fuse_arg) {
+ .size = dentry->d_name.len + 1,
+ .max_size = NAME_MAX + 1,
+ .flags = BPF_FUSE_VARIABLE_SIZE | BPF_FUSE_MUST_ALLOCATE,
+ .value = (void *) dentry->d_name.name,
+ },
+ /*
+ * .out_argvar = 1,
+ * .out_numargs = 1,
+ * .out_args[0].size = ,
+ * .out_args[0].value = ,
+ */
+ };
+
+ return 0;
+}
+
+int fuse_get_link_initialize_out(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback)
+{
+ /*
+ * .out_argvar = 1,
+ * .out_numargs = 1,
+ * .out_args[0].size = ,
+ * .out_args[0].value = ,
+ */
+
+ return 0;
+}
+
+int fuse_get_link_backing(struct bpf_fuse_args *fa, const char **out,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback)
+{
+ struct path backing_path;
+
+ if (!dentry) {
+ *out = ERR_PTR(-ECHILD);
+ return PTR_ERR(*out);
+ }
+
+ get_fuse_backing_path(dentry, &backing_path);
+ if (!backing_path.dentry) {
+ *out = ERR_PTR(-ECHILD);
+ return PTR_ERR(*out);
+ }
+
+ /*
+ * TODO: If we want to do our own thing, copy the data and then call the
+ * callback
+ */
+ *out = vfs_get_link(backing_path.dentry, callback);
+
+ path_put(&backing_path);
+ return 0;
+}
+
+int fuse_get_link_finalize(struct bpf_fuse_args *fa, const char **out,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback)
+{
+ return 0;
+}
+
+int fuse_symlink_initialize_in(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *dir, struct dentry *entry, const char *link, int len)
+{
+ *fa = (struct bpf_fuse_args) {
+ .nodeid = get_node_id(dir),
+ .opcode = FUSE_SYMLINK,
+ .in_numargs = 2,
+ .in_args[0] = (struct bpf_fuse_arg) {
+ .size = entry->d_name.len + 1,
+ .flags = BPF_FUSE_IMMUTABLE,
+ .value = (void *) entry->d_name.name,
+ },
+ .in_args[1] = (struct bpf_fuse_arg) {
+ .size = len,
+ .max_size = PATH_MAX,
+ .flags = BPF_FUSE_VARIABLE_SIZE | BPF_FUSE_MUST_ALLOCATE,
+ .value = (void *) link,
+ },
+ };
+
+ return 0;
+}
+
+int fuse_symlink_initialize_out(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *dir, struct dentry *entry, const char *link, int len)
+{
+ return 0;
+}
+
+int fuse_symlink_backing(struct bpf_fuse_args *fa, int *out,
+ struct inode *dir, struct dentry *entry, const char *link, int len)
+{
+ struct fuse_inode *fuse_inode = get_fuse_inode(dir);
+ struct inode *backing_inode = fuse_inode->backing_inode;
+ struct path backing_path;
+ struct inode *inode = NULL;
+
+ *out = 0;
+ //TODO Actually deal with changing the backing entry in symlink
+ get_fuse_backing_path(entry, &backing_path);
+ if (!backing_path.dentry)
+ return -EBADF;
+
+ inode_lock_nested(backing_inode, I_MUTEX_PARENT);
+ *out = vfs_symlink(&init_user_ns, backing_inode, backing_path.dentry,
+ link);
+ inode_unlock(backing_inode);
+ if (*out)
+ goto out;
+ if (d_really_is_negative(backing_path.dentry) ||
+ unlikely(d_unhashed(backing_path.dentry))) {
+ *out = -EINVAL;
+ /**
+ * TODO: overlayfs responds to this situation with a
+ * lookupOneLen. Should we do that too?
+ */
+ goto out;
+ }
+ inode = fuse_iget_backing(dir->i_sb, fuse_inode->nodeid, backing_inode);
+ if (IS_ERR(inode)) {
+ *out = PTR_ERR(inode);
+ goto out;
+ }
+ d_instantiate(entry, inode);
+out:
+ path_put(&backing_path);
+ return *out;
+}
+
+int fuse_symlink_finalize(struct bpf_fuse_args *fa, int *out,
+ struct inode *dir, struct dentry *entry, const char *link, int len)
+{
+ 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)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index af1f715a405d..a4fd1cb018be 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -967,6 +967,16 @@ static int fuse_symlink(struct user_namespace *mnt_userns, struct inode *dir,
unsigned len = strlen(link) + 1;
FUSE_ARGS(args);
+#ifdef CONFIG_FUSE_BPF
+ int err;
+
+ if (fuse_bpf_backing(dir, struct fuse_dummy_io, err,
+ fuse_symlink_initialize_in, fuse_symlink_initialize_out,
+ fuse_symlink_backing, fuse_symlink_finalize,
+ dir, entry, link, len))
+ return err;
+#endif
+
args.opcode = FUSE_SYMLINK;
args.in_numargs = 2;
args.in_args[0].size = entry->d_name.len + 1;
@@ -1198,6 +1208,14 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
struct fuse_mount *fm = get_fuse_mount(inode);
FUSE_ARGS(args);
+#ifdef CONFIG_FUSE_BPF
+ if (fuse_bpf_backing(inode, struct fuse_link_in, err,
+ fuse_link_initialize_in, fuse_link_initialize_out,
+ fuse_link_backing, fuse_link_finalize, entry,
+ newdir, newent))
+ return err;
+#endif
+
memset(&inarg, 0, sizeof(inarg));
inarg.oldnodeid = get_node_id(inode);
args.opcode = FUSE_LINK;
@@ -1609,6 +1627,19 @@ static const char *fuse_get_link(struct dentry *dentry, struct inode *inode,
if (fuse_is_bad(inode))
goto out_err;
+#ifdef CONFIG_FUSE_BPF
+ {
+ const char *out = NULL;
+
+ if (fuse_bpf_backing(inode, struct fuse_dummy_io, out,
+ fuse_get_link_initialize_in, fuse_get_link_initialize_out,
+ fuse_get_link_backing,
+ fuse_get_link_finalize,
+ inode, dentry, callback))
+ return out;
+ }
+#endif
+
if (fc->cache_symlinks)
return page_get_link(dentry, inode, callback);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b313a45c7774..cbfd56d669c7 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1504,6 +1504,17 @@ int fuse_unlink_backing(struct bpf_fuse_args *fa, int *out,
int fuse_unlink_finalize(struct bpf_fuse_args *fa, int *out,
struct inode *dir, struct dentry *entry);
+int fuse_link_initialize_in(struct bpf_fuse_args *fa, struct fuse_link_in *fli,
+ struct dentry *entry, struct inode *dir,
+ struct dentry *newent);
+int fuse_link_initialize_out(struct bpf_fuse_args *fa, struct fuse_link_in *fli,
+ struct dentry *entry, struct inode *dir,
+ struct dentry *newent);
+int fuse_link_backing(struct bpf_fuse_args *fa, int *out, struct dentry *entry,
+ struct inode *dir, struct dentry *newent);
+int fuse_link_finalize(struct bpf_fuse_args *fa, int *out, struct dentry *entry,
+ struct inode *dir, struct dentry *newent);
+
int fuse_release_initialize_in(struct bpf_fuse_args *fa, struct fuse_release_in *fri,
struct inode *inode, struct file *file);
int fuse_release_initialize_out(struct bpf_fuse_args *fa, struct fuse_release_in *fri,
@@ -1742,6 +1753,28 @@ int fuse_statfs_backing(struct bpf_fuse_args *fa, int *out,
int fuse_statfs_finalize(struct bpf_fuse_args *fa, int *out,
struct dentry *dentry, struct kstatfs *buf);
+int fuse_get_link_initialize_in(struct bpf_fuse_args *fa, struct fuse_dummy_io *dummy,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback);
+int fuse_get_link_initialize_out(struct bpf_fuse_args *fa, struct fuse_dummy_io *dummy,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback);
+int fuse_get_link_backing(struct bpf_fuse_args *fa, const char **out,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback);
+int fuse_get_link_finalize(struct bpf_fuse_args *fa, const char **out,
+ struct inode *inode, struct dentry *dentry,
+ struct delayed_call *callback);
+
+int fuse_symlink_initialize_in(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *dir, struct dentry *entry, const char *link, int len);
+int fuse_symlink_initialize_out(struct bpf_fuse_args *fa, struct fuse_dummy_io *unused,
+ struct inode *dir, struct dentry *entry, const char *link, int len);
+int fuse_symlink_backing(struct bpf_fuse_args *fa, int *out,
+ struct inode *dir, struct dentry *entry, const char *link, int len);
+int fuse_symlink_finalize(struct bpf_fuse_args *fa, int *out,
+ struct inode *dir, struct dentry *entry, const char *link, int len);
+
struct fuse_read_io {
struct fuse_read_in fri;
struct fuse_read_out fro;
--
2.37.3.998.g577e59143f-goog
next prev parent reply other threads:[~2022-09-26 23:21 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 ` [PATCH 16/26] fuse-bpf: support FUSE_READDIR Daniel Rosenberg
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 ` Daniel Rosenberg [this message]
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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