From 7a8721f84fcb3b2946a92380b6fc311e017ff02c Mon Sep 17 00:00:00 2001 From: Dmitry Kadashev Date: Thu, 8 Jul 2021 13:34:46 +0700 Subject: [PATCH] io_uring: add support for IORING_OP_SYMLINKAT IORING_OP_SYMLINKAT behaves like symlinkat(2) and takes the same flags and arguments. Acked-by: Linus Torvalds Suggested-by: Christian Brauner Link: https://lore.kernel.org/io-uring/20210514145259.wtl4xcsp52woi6ab@wittgenstein/ Signed-off-by: Dmitry Kadashev Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20210708063447.3556403-11-dkadashev@gmail.com [axboe: add splice_fd_in check] Signed-off-by: Jens Axboe --- fs/internal.h | 1 + fs/io_uring.c | 67 +++++++++++++++++++++++++++++++++++ fs/namei.c | 3 +- include/uapi/linux/io_uring.h | 1 + 4 files changed, 70 insertions(+), 2 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index d6b15dad1310..2f9750aefbd6 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -77,6 +77,7 @@ int may_linkat(struct user_namespace *mnt_userns, struct path *link); int do_renameat2(int olddfd, struct filename *oldname, int newdfd, struct filename *newname, unsigned int flags); int do_mkdirat(int dfd, struct filename *name, umode_t mode); +int do_symlinkat(struct filename *from, int newdfd, struct filename *to); /* * namespace.c diff --git a/fs/io_uring.c b/fs/io_uring.c index 8e14e71bf6ac..33941df9084b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -669,6 +669,13 @@ struct io_mkdir { struct filename *filename; }; +struct io_symlink { + struct file *file; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; +}; + struct io_completion { struct file *file; u32 cflags; @@ -829,6 +836,7 @@ struct io_kiocb { struct io_rename rename; struct io_unlink unlink; struct io_mkdir mkdir; + struct io_symlink symlink; /* use only after cleaning per-op data, see io_clean_op() */ struct io_completion compl; }; @@ -1041,6 +1049,7 @@ static const struct io_op_def io_op_defs[] = { [IORING_OP_RENAMEAT] = {}, [IORING_OP_UNLINKAT] = {}, [IORING_OP_MKDIRAT] = {}, + [IORING_OP_SYMLINKAT] = {}, }; /* requests with any of those set should undergo io_disarm_next() */ @@ -3655,6 +3664,55 @@ static int io_mkdirat(struct io_kiocb *req, int issue_flags) return 0; } +static int io_symlinkat_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_symlink *sl = &req->symlink; + const char __user *oldpath, *newpath; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->ioprio || sqe->len || sqe->rw_flags || sqe->buf_index || + sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + sl->new_dfd = READ_ONCE(sqe->fd); + oldpath = u64_to_user_ptr(READ_ONCE(sqe->addr)); + newpath = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + + sl->oldpath = getname(oldpath); + if (IS_ERR(sl->oldpath)) + return PTR_ERR(sl->oldpath); + + sl->newpath = getname(newpath); + if (IS_ERR(sl->newpath)) { + putname(sl->oldpath); + return PTR_ERR(sl->newpath); + } + + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +} + +static int io_symlinkat(struct io_kiocb *req, int issue_flags) +{ + struct io_symlink *sl = &req->symlink; + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + ret = do_symlinkat(sl->oldpath, sl->new_dfd, sl->newpath); + + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail(req); + io_req_complete(req, ret); + return 0; +} + static int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { @@ -6054,6 +6112,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return io_unlinkat_prep(req, sqe); case IORING_OP_MKDIRAT: return io_mkdirat_prep(req, sqe); + case IORING_OP_SYMLINKAT: + return io_symlinkat_prep(req, sqe); } printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", @@ -6220,6 +6280,10 @@ static void io_clean_op(struct io_kiocb *req) case IORING_OP_MKDIRAT: putname(req->mkdir.filename); break; + case IORING_OP_SYMLINKAT: + putname(req->symlink.oldpath); + putname(req->symlink.newpath); + break; } } if ((req->flags & REQ_F_POLLED) && req->apoll) { @@ -6351,6 +6415,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) case IORING_OP_MKDIRAT: ret = io_mkdirat(req, issue_flags); break; + case IORING_OP_SYMLINKAT: + ret = io_symlinkat(req, issue_flags); + break; default: ret = -EINVAL; break; diff --git a/fs/namei.c b/fs/namei.c index e2425c0a406e..803fc95b7658 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4223,8 +4223,7 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir, } EXPORT_SYMBOL(vfs_symlink); -static int do_symlinkat(struct filename *from, int newdfd, - struct filename *to) +int do_symlinkat(struct filename *from, int newdfd, struct filename *to) { int error; struct dentry *dentry; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index a926407c230e..61fd347ab176 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -134,6 +134,7 @@ enum { IORING_OP_RENAMEAT, IORING_OP_UNLINKAT, IORING_OP_MKDIRAT, + IORING_OP_SYMLINKAT, /* this goes last, obviously */ IORING_OP_LAST,