Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
Signed-off-by: Paul Lawrence <paullawrence@xxxxxxxxxx>
---
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
