[RFC,v2,12/21] fuse-bpf: Support mknod/unlink/mkdir/rmdir

Message ID	20221122021536.1629178-13-drosen@google.com (mailing list archive)
State	RFC
Headers	show Return-Path: <bpf-owner@kernel.org> Date: Mon, 21 Nov 2022 18:15:27 -0800 In-Reply-To: <20221122021536.1629178-1-drosen@google.com> Mime-Version: 1.0 References: <20221122021536.1629178-1-drosen@google.com> Message-ID: <20221122021536.1629178-13-drosen@google.com> Subject: [RFC PATCH v2 12/21] fuse-bpf: Support mknod/unlink/mkdir/rmdir From: Daniel Rosenberg <drosen@google.com> To: Miklos Szeredi <miklos@szeredi.hu> Cc: Amir Goldstein <amir73il@gmail.com>, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, bpf@vger.kernel.org, kernel-team@android.com, Daniel Rosenberg <drosen@google.com>, Paul Lawrence <paullawrence@google.com> Content-Type: text/plain; charset="UTF-8" Precedence: bulk
Series	FUSE BPF: A Stacked Filesystem Extension for FUSE \| expand [RFC,v2,00/21] FUSE BPF: A Stacked Filesystem Extension for FUSE [RFC,v2,01/21] fs: Generic function to convert iocb to rw flags [RFC,v2,02/21] fuse-bpf: Update fuse side uapi [RFC,v2,03/21] fuse-bpf: Prepare for fuse-bpf patch [RFC,v2,04/21] fuse: Add fuse-bpf, a stacked fs extension for FUSE [RFC,v2,05/21] fuse-bpf: Add ioctl interface for /dev/fuse [RFC,v2,06/21] fuse-bpf: Don't support export_operations [RFC,v2,07/21] fuse-bpf: Add support for FUSE_ACCESS [RFC,v2,08/21] fuse-bpf: Partially add mapping support [RFC,v2,09/21] fuse-bpf: Add lseek support [RFC,v2,10/21] fuse-bpf: Add support for fallocate [RFC,v2,11/21] fuse-bpf: Support file/dir open/close [RFC,v2,12/21] fuse-bpf: Support mknod/unlink/mkdir/rmdir [RFC,v2,13/21] fuse-bpf: Add support for read/write iter [RFC,v2,14/21] fuse-bpf: support FUSE_READDIR [RFC,v2,15/21] fuse-bpf: Add support for sync operations [RFC,v2,16/21] fuse-bpf: Add Rename support [RFC,v2,17/21] fuse-bpf: Add attr support [RFC,v2,18/21] fuse-bpf: Add support for FUSE_COPY_FILE_RANGE [RFC,v2,19/21] fuse-bpf: Add xattr support [RFC,v2,20/21] fuse-bpf: Add symlink/link support [RFC,v2,21/21] fuse-bpf: allow mounting with no userspace daemon

Context	Check	Description
netdev/tree_selection	success	Not a local patch

diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c index c8e95abc04aa..a7505d6887e0 100644 --- a/fs/fuse/backing.c +++ b/fs/fuse/backing.c @@ -205,6 +205,13 @@ static void fuse_stat_to_attr(struct fuse_conn *fc, struct inode *inode, attr->blksize = 1 << blkbits; } +/* + * Unused io passed to fuse_bpf_backing when io operation needs no scratch space + */ +struct fuse_unused_io { + int unused; +}; + struct fuse_open_io { struct fuse_open_in foi; struct fuse_open_out foo; @@ -930,6 +937,305 @@ int fuse_revalidate_backing(struct dentry *entry, unsigned int flags) return 1; } +static int fuse_mknod_initialize_in(struct fuse_args *fa, struct fuse_mknod_in *fmi, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + *fmi = (struct fuse_mknod_in) { + .mode = mode, + .rdev = new_encode_dev(rdev), + .umask = current_umask(), + }; + *fa = (struct fuse_args) { + .nodeid = get_node_id(dir), + .opcode = FUSE_MKNOD, + .in_numargs = 2, + .in_args[0] = (struct fuse_in_arg) { + .size = sizeof(*fmi), + .value = fmi, + }, + .in_args[1] = (struct fuse_in_arg) { + .size = entry->d_name.len + 1, + .value = (void *) entry->d_name.name, + }, + }; + + return 0; +} + +static int fuse_mknod_initialize_out(struct fuse_args *fa, struct fuse_mknod_in *fmi, + struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev) +{ + return 0; +} + +static int fuse_mknod_backing(struct 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(&init_user_ns, 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 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 fuse_bpf_backing(dir, struct fuse_mknod_in, out, + fuse_mknod_initialize_in, fuse_mknod_initialize_out, + fuse_mknod_backing, fuse_mknod_finalize, + dir, entry, mode, rdev); +} + +static int fuse_mkdir_initialize_in(struct fuse_args *fa, struct fuse_mkdir_in *fmi, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + *fmi = (struct fuse_mkdir_in) { + .mode = mode, + .umask = current_umask(), + }; + *fa = (struct fuse_args) { + .nodeid = get_node_id(dir), + .opcode = FUSE_MKDIR, + .in_numargs = 2, + .in_args[0] = (struct fuse_in_arg) { + .size = sizeof(*fmi), + .value = fmi, + }, + .in_args[1] = (struct fuse_in_arg) { + .size = entry->d_name.len + 1, + .value = (void *) entry->d_name.name, + }, + }; + + return 0; +} + +static int fuse_mkdir_initialize_out(struct fuse_args *fa, struct fuse_mkdir_in *fmi, + struct inode *dir, struct dentry *entry, umode_t mode) +{ + return 0; +} + +static int fuse_mkdir_backing(struct 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(&init_user_ns, 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 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 fuse_bpf_backing(dir, struct fuse_mkdir_in, 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 fuse_args *fa, struct fuse_unused_io *unused, + struct inode *dir, struct dentry *entry) +{ + *fa = (struct fuse_args) { + .nodeid = get_node_id(dir), + .opcode = FUSE_RMDIR, + .in_numargs = 1, + .in_args[0] = (struct fuse_in_arg) { + .size = entry->d_name.len + 1, + .value = (void *) entry->d_name.name, + }, + }; + + return 0; +} + +static int fuse_rmdir_initialize_out(struct fuse_args *fa, struct fuse_unused_io *unused, + struct inode *dir, struct dentry *entry) +{ + return 0; +} + +static int fuse_rmdir_backing(struct 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(&init_user_ns, 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 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 fuse_bpf_backing(dir, struct fuse_unused_io, out, + fuse_rmdir_initialize_in, fuse_rmdir_initialize_out, + fuse_rmdir_backing, fuse_rmdir_finalize, + dir, entry); +} + +static int fuse_unlink_initialize_in(struct fuse_args *fa, struct fuse_unused_io *unused, + struct inode *dir, struct dentry *entry) +{ + *fa = (struct fuse_args) { + .nodeid = get_node_id(dir), + .opcode = FUSE_UNLINK, + .in_numargs = 1, + .in_args[0] = (struct fuse_in_arg) { + .size = entry->d_name.len + 1, + .value = (void *) entry->d_name.name, + }, + }; + + return 0; +} + +static int fuse_unlink_initialize_out(struct fuse_args *fa, struct fuse_unused_io *unused, + struct inode *dir, struct dentry *entry) +{ + return 0; +} + +static int fuse_unlink_backing(struct 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(&init_user_ns, 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 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 fuse_bpf_backing(dir, struct fuse_unused_io, out, + fuse_unlink_initialize_in, fuse_unlink_initialize_out, + fuse_unlink_backing, fuse_unlink_finalize, + dir, entry); +} + static int fuse_access_initialize_in(struct fuse_args *fa, struct fuse_access_in *fai, struct inode *inode, int mask) { diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index e330a6af9ee7..729a0348fa01 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -869,6 +869,10 @@ static int fuse_mknod(struct user_namespace *mnt_userns, 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(); @@ -915,6 +919,10 @@ static int fuse_mkdir(struct user_namespace *mnt_userns, 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(); @@ -1001,6 +1009,9 @@ 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; @@ -1024,6 +1035,9 @@ 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 794b1a06079c..dc5bba2a75ab 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1403,6 +1403,10 @@ 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 file *file); int fuse_bpf_releasedir(int *out, struct inode *inode, struct file *file); int fuse_bpf_lseek(loff_t *out, struct inode *inode, struct file *file, loff_t offset, int whence); @@ -1423,6 +1427,26 @@ 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;

[RFC,v2,12/21] fuse-bpf: Support mknod/unlink/mkdir/rmdir

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