This adds backing support for FUSE_MKNOD, FUSE_MKDIR, FUSE_RMDIR, and FUSE_UNLINK Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx> Signed-off-by: Paul Lawrence <paullawrence@xxxxxxxxxx> --- fs/fuse/backing.c | 342 ++++++++++++++++++++++++++++++++++++++++++++++ fs/fuse/dir.c | 14 ++ fs/fuse/fuse_i.h | 24 ++++ 3 files changed, 380 insertions(+) diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c index 317a3adbbb3e..567f859d300c 100644 --- a/fs/fuse/backing.c +++ b/fs/fuse/backing.c @@ -947,6 +947,348 @@ int fuse_revalidate_backing(struct dentry *entry, unsigned int flags) return 1; } +struct fuse_mknod_args { + struct fuse_mknod_in in; + struct fuse_buffer name; +}; + +static int fuse_mknod_initialize_in(struct bpf_fuse_args *fa, struct fuse_mknod_args *args, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + *args = (struct fuse_mknod_args) { + .in = (struct fuse_mknod_in) { + .mode = mode, + .rdev = new_encode_dev(rdev), + .umask = current_umask(), + }, + .name = (struct fuse_buffer) { + .data = (void *) entry->d_name.name, + .size = entry->d_name.len + 1, + .flags = BPF_FUSE_IMMUTABLE, + }, + }; + *fa = (struct bpf_fuse_args) { + .info = (struct bpf_fuse_meta_info) { + .nodeid = get_node_id(dir), + .opcode = FUSE_MKNOD, + }, + .in_numargs = 2, + .in_args[0] = (struct bpf_fuse_arg) { + .size = sizeof(args->in), + .value = &args->in, + }, + .in_args[1] = (struct bpf_fuse_arg) { + .is_buffer = true, + .buffer = &args->name, + }, + }; + + return 0; +} + +static int fuse_mknod_initialize_out(struct bpf_fuse_args *fa, struct fuse_mknod_args *args, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + return 0; +} + +static int fuse_mknod_backing(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + const struct fuse_mknod_in *fmi = fa->in_args[0].value; + 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; + + get_fuse_backing_path(entry, &backing_path); + if (!backing_path.dentry) + return -EBADF; + + inode_lock_nested(backing_inode, I_MUTEX_PARENT); + mode = fmi->mode; + if (!IS_POSIXACL(backing_inode)) + mode &= ~fmi->umask; + *out = vfs_mknod(&nop_mnt_idmap, backing_inode, backing_path.dentry, mode, + new_decode_dev(fmi->rdev)); + 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; +} + +static int fuse_mknod_finalize(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + return 0; +} + +int fuse_bpf_mknod(int *out, struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + return bpf_fuse_backing(dir, struct fuse_mknod_args, out, + fuse_mknod_initialize_in, fuse_mknod_initialize_out, + fuse_mknod_backing, fuse_mknod_finalize, + dir, entry, mode, rdev); +} + +struct fuse_mkdir_args { + struct fuse_mkdir_in in; + struct fuse_buffer name; +}; + +static int fuse_mkdir_initialize_in(struct bpf_fuse_args *fa, struct fuse_mkdir_args *args, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + *args = (struct fuse_mkdir_args) { + .in = (struct fuse_mkdir_in) { + .mode = mode, + .umask = current_umask(), + }, + .name = (struct fuse_buffer) { + .data = (void *) entry->d_name.name, + .size = entry->d_name.len + 1, + .flags = BPF_FUSE_IMMUTABLE, + }, + }; + + *fa = (struct bpf_fuse_args) { + .info = (struct bpf_fuse_meta_info) { + .nodeid = get_node_id(dir), + .opcode = FUSE_MKDIR, + }, + .in_numargs = 2, + .in_args[0] = (struct bpf_fuse_arg) { + .size = sizeof(args->in), + .value = &args->in, + }, + .in_args[1] = (struct bpf_fuse_arg) { + .value = &args->name, + .is_buffer = true, + }, + }; + + return 0; +} + +static int fuse_mkdir_initialize_out(struct bpf_fuse_args *fa, struct fuse_mkdir_args *args, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + return 0; +} + +static int fuse_mkdir_backing(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + const struct fuse_mkdir_in *fmi = fa->in_args[0].value; + 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; + struct dentry *d; + + get_fuse_backing_path(entry, &backing_path); + if (!backing_path.dentry) + return -EBADF; + + inode_lock_nested(backing_inode, I_MUTEX_PARENT); + mode = fmi->mode; + if (!IS_POSIXACL(backing_inode)) + mode &= ~fmi->umask; + *out = vfs_mkdir(&nop_mnt_idmap, backing_inode, backing_path.dentry, + mode); + if (*out) + goto out; + if (d_really_is_negative(backing_path.dentry) || + unlikely(d_unhashed(backing_path.dentry))) { + d = lookup_one_len(entry->d_name.name, + backing_path.dentry->d_parent, + entry->d_name.len); + if (IS_ERR(d)) { + *out = PTR_ERR(d); + goto out; + } + dput(backing_path.dentry); + backing_path.dentry = d; + } + 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: + inode_unlock(backing_inode); + path_put(&backing_path); + return *out; +} + +static int fuse_mkdir_finalize(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + return 0; +} + +int fuse_bpf_mkdir(int *out, struct inode *dir, struct dentry *entry, umode_t mode) +{ + return bpf_fuse_backing(dir, struct fuse_mkdir_args, out, + fuse_mkdir_initialize_in, fuse_mkdir_initialize_out, + fuse_mkdir_backing, fuse_mkdir_finalize, + dir, entry, mode); +} + +static int fuse_rmdir_initialize_in(struct bpf_fuse_args *fa, struct fuse_buffer *name, + struct inode *dir, struct dentry *entry) +{ + *name = (struct fuse_buffer) { + .data = (void *) entry->d_name.name, + .size = entry->d_name.len + 1, + .flags = BPF_FUSE_IMMUTABLE, + }; + *fa = (struct bpf_fuse_args) { + .info = (struct bpf_fuse_meta_info) { + .nodeid = get_node_id(dir), + .opcode = FUSE_RMDIR, + }, + .in_numargs = 1, + .in_args[0] = (struct bpf_fuse_arg) { + .is_buffer = true, + .buffer = name, + }, + }; + + return 0; +} + +static int fuse_rmdir_initialize_out(struct bpf_fuse_args *fa, struct fuse_buffer *name, + struct inode *dir, struct dentry *entry) +{ + return 0; +} + +static int fuse_rmdir_backing(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry) +{ + struct path backing_path; + struct dentry *backing_parent_dentry; + struct inode *backing_inode; + + get_fuse_backing_path(entry, &backing_path); + if (!backing_path.dentry) + return -EBADF; + + backing_parent_dentry = dget_parent(backing_path.dentry); + backing_inode = d_inode(backing_parent_dentry); + + inode_lock_nested(backing_inode, I_MUTEX_PARENT); + *out = vfs_rmdir(&nop_mnt_idmap, backing_inode, backing_path.dentry); + inode_unlock(backing_inode); + + dput(backing_parent_dentry); + if (!*out) + d_drop(entry); + path_put(&backing_path); + return *out; +} + +static int fuse_rmdir_finalize(struct bpf_fuse_args *fa, int *out, struct inode *dir, struct dentry *entry) +{ + return 0; +} + +int fuse_bpf_rmdir(int *out, struct inode *dir, struct dentry *entry) +{ + return bpf_fuse_backing(dir, struct fuse_buffer, out, + fuse_rmdir_initialize_in, fuse_rmdir_initialize_out, + fuse_rmdir_backing, fuse_rmdir_finalize, + dir, entry); +} + +static int fuse_unlink_initialize_in(struct bpf_fuse_args *fa, struct fuse_buffer *name, + struct inode *dir, struct dentry *entry) +{ + *name = (struct fuse_buffer) { + .data = (void *) entry->d_name.name, + .size = entry->d_name.len + 1, + .flags = BPF_FUSE_IMMUTABLE, + }; + *fa = (struct bpf_fuse_args) { + .info = (struct bpf_fuse_meta_info) { + .nodeid = get_node_id(dir), + .opcode = FUSE_UNLINK, + }, + .in_numargs = 1, + .in_args[0] = (struct bpf_fuse_arg) { + .is_buffer = true, + .buffer = name, + }, + }; + + return 0; +} + +static int fuse_unlink_initialize_out(struct bpf_fuse_args *fa, struct fuse_buffer *name, + struct inode *dir, struct dentry *entry) +{ + return 0; +} + +static int fuse_unlink_backing(struct bpf_fuse_args *fa, int *out, struct inode *dir, struct dentry *entry) +{ + struct path backing_path; + struct dentry *backing_parent_dentry; + struct inode *backing_inode; + + get_fuse_backing_path(entry, &backing_path); + if (!backing_path.dentry) + return -EBADF; + + /* TODO Not sure if we should reverify like overlayfs, or get inode from d_parent */ + backing_parent_dentry = dget_parent(backing_path.dentry); + backing_inode = d_inode(backing_parent_dentry); + + inode_lock_nested(backing_inode, I_MUTEX_PARENT); + *out = vfs_unlink(&nop_mnt_idmap, backing_inode, backing_path.dentry, + NULL); + inode_unlock(backing_inode); + + dput(backing_parent_dentry); + if (!*out) + d_drop(entry); + path_put(&backing_path); + return *out; +} + +static int fuse_unlink_finalize(struct bpf_fuse_args *fa, int *out, + struct inode *dir, struct dentry *entry) +{ + return 0; +} + +int fuse_bpf_unlink(int *out, struct inode *dir, struct dentry *entry) +{ + return bpf_fuse_backing(dir, struct fuse_buffer, out, + fuse_unlink_initialize_in, fuse_unlink_initialize_out, + fuse_unlink_backing, fuse_unlink_finalize, + dir, entry); +} + static int fuse_access_initialize_in(struct bpf_fuse_args *fa, struct fuse_access_in *in, struct inode *inode, int mask) { diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 09bb4c63fd71..a5b6aef788b2 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -957,6 +957,10 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir, struct fuse_mknod_in inarg; struct fuse_mount *fm = get_fuse_mount(dir); FUSE_ARGS(args); + int err; + + if (fuse_bpf_mknod(&err, dir, entry, mode, rdev)) + return err; if (!fm->fc->dont_mask) mode &= ~current_umask(); @@ -1003,6 +1007,10 @@ static int fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir, struct fuse_mkdir_in inarg; struct fuse_mount *fm = get_fuse_mount(dir); FUSE_ARGS(args); + int err; + + if (fuse_bpf_mkdir(&err, dir, entry, mode)) + return err; if (!fm->fc->dont_mask) mode &= ~current_umask(); @@ -1089,6 +1097,9 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) if (fuse_is_bad(dir)) return -EIO; + if (fuse_bpf_unlink(&err, dir, entry)) + return err; + args.opcode = FUSE_UNLINK; args.nodeid = get_node_id(dir); args.in_numargs = 1; @@ -1112,6 +1123,9 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry) if (fuse_is_bad(dir)) return -EIO; + if (fuse_bpf_rmdir(&err, dir, entry)) + return err; + args.opcode = FUSE_RMDIR; args.nodeid = get_node_id(dir); args.in_numargs = 1; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index a133010fde1c..9b176f78999f 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1441,6 +1441,10 @@ int parse_fuse_bpf_entry(struct fuse_bpf_entry *fbe, int num_entries); int fuse_bpf_open(int *err, struct inode *inode, struct file *file, bool isdir); int fuse_bpf_create_open(int *out, struct inode *dir, struct dentry *entry, struct file *file, unsigned int flags, umode_t mode); +int fuse_bpf_mknod(int *out, struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev); +int fuse_bpf_mkdir(int *out, struct inode *dir, struct dentry *entry, umode_t mode); +int fuse_bpf_rmdir(int *out, struct inode *dir, struct dentry *entry); +int fuse_bpf_unlink(int *out, struct inode *dir, struct dentry *entry); int fuse_bpf_release(int *out, struct inode *inode, struct fuse_file *ff); int fuse_bpf_releasedir(int *out, struct inode *inode, struct fuse_file *ff); int fuse_bpf_lseek(loff_t *out, struct inode *inode, struct file *file, loff_t offset, int whence); @@ -1461,6 +1465,26 @@ static inline int fuse_bpf_create_open(int *out, struct inode *dir, struct dentr return 0; } +static inline int fuse_bpf_mknod(int *out, struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + return 0; +} + +static inline int fuse_bpf_mkdir(int *out, struct inode *dir, struct dentry *entry, umode_t mode) +{ + return 0; +} + +static inline int fuse_bpf_rmdir(int *out, struct inode *dir, struct dentry *entry) +{ + return 0; +} + +static inline int fuse_bpf_unlink(int *out, struct inode *dir, struct dentry *entry) +{ + return 0; +} + static inline int fuse_bpf_release(int *out, struct inode *inode, struct file *file) { return 0; -- 2.44.0.478.gd926399ef9-goog