On 6/24/21 12:14 PM, Dmitry Kadashev wrote: > IORING_OP_LINKAT behaves like linkat(2) and takes the same flags and > arguments. > > In some internal places 'hardlink' is used instead of 'link' to avoid > confusion with the SQE links. Name 'link' conflicts with the existing > 'link' member of io_kiocb. Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx> > > Suggested-by: Christian Brauner <christian.brauner@xxxxxxxxxx> > Link: https://lore.kernel.org/io-uring/20210514145259.wtl4xcsp52woi6ab@wittgenstein/ > Signed-off-by: Dmitry Kadashev <dkadashev@xxxxxxxxx> > Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx> > --- > fs/internal.h | 2 + > fs/io_uring.c | 71 +++++++++++++++++++++++++++++++++++ > fs/namei.c | 2 +- > include/uapi/linux/io_uring.h | 2 + > 4 files changed, 76 insertions(+), 1 deletion(-) > > diff --git a/fs/internal.h b/fs/internal.h > index 3b3954214385..15a7d210cc67 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -79,6 +79,8 @@ 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); > +int do_linkat(int olddfd, struct filename *old, int newdfd, > + struct filename *new, int flags); > > /* > * namespace.c > diff --git a/fs/io_uring.c b/fs/io_uring.c > index c161f06a3cea..14a90e4e4149 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -687,6 +687,15 @@ struct io_symlink { > struct filename *newpath; > }; > > +struct io_hardlink { > + struct file *file; > + int old_dfd; > + int new_dfd; > + struct filename *oldpath; > + struct filename *newpath; > + int flags; > +}; > + > struct io_completion { > struct file *file; > struct list_head list; > @@ -841,6 +850,7 @@ struct io_kiocb { > struct io_unlink unlink; > struct io_mkdir mkdir; > struct io_symlink symlink; > + struct io_hardlink hardlink; > /* use only after cleaning per-op data, see io_clean_op() */ > struct io_completion compl; > }; > @@ -1057,6 +1067,7 @@ static const struct io_op_def io_op_defs[] = { > [IORING_OP_UNLINKAT] = {}, > [IORING_OP_MKDIRAT] = {}, > [IORING_OP_SYMLINKAT] = {}, > + [IORING_OP_LINKAT] = {}, > }; > > static bool io_disarm_next(struct io_kiocb *req); > @@ -3656,6 +3667,57 @@ static int io_symlinkat(struct io_kiocb *req, int issue_flags) > return 0; > } > > +static int io_linkat_prep(struct io_kiocb *req, > + const struct io_uring_sqe *sqe) > +{ > + struct io_hardlink *lnk = &req->hardlink; > + const char __user *oldf, *newf; > + > + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) > + return -EINVAL; > + if (sqe->ioprio || sqe->rw_flags || sqe->buf_index) > + return -EINVAL; > + if (unlikely(req->flags & REQ_F_FIXED_FILE)) > + return -EBADF; > + > + lnk->old_dfd = READ_ONCE(sqe->fd); > + lnk->new_dfd = READ_ONCE(sqe->len); > + oldf = u64_to_user_ptr(READ_ONCE(sqe->addr)); > + newf = u64_to_user_ptr(READ_ONCE(sqe->addr2)); > + lnk->flags = READ_ONCE(sqe->hardlink_flags); > + > + lnk->oldpath = getname(oldf); > + if (IS_ERR(lnk->oldpath)) > + return PTR_ERR(lnk->oldpath); > + > + lnk->newpath = getname(newf); > + if (IS_ERR(lnk->newpath)) { > + putname(lnk->oldpath); > + return PTR_ERR(lnk->newpath); > + } > + > + req->flags |= REQ_F_NEED_CLEANUP; > + return 0; > +} > + > +static int io_linkat(struct io_kiocb *req, int issue_flags) > +{ > + struct io_hardlink *lnk = &req->hardlink; > + int ret; > + > + if (issue_flags & IO_URING_F_NONBLOCK) > + return -EAGAIN; > + > + ret = do_linkat(lnk->old_dfd, lnk->oldpath, lnk->new_dfd, > + lnk->newpath, lnk->flags); > + > + 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) > { > @@ -6068,6 +6130,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) > return io_mkdirat_prep(req, sqe); > case IORING_OP_SYMLINKAT: > return io_symlinkat_prep(req, sqe); > + case IORING_OP_LINKAT: > + return io_linkat_prep(req, sqe); > } > > printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", > @@ -6236,6 +6300,10 @@ static void io_clean_op(struct io_kiocb *req) > putname(req->symlink.oldpath); > putname(req->symlink.newpath); > break; > + case IORING_OP_LINKAT: > + putname(req->hardlink.oldpath); > + putname(req->hardlink.newpath); > + break; > } > } > if ((req->flags & REQ_F_POLLED) && req->apoll) { > @@ -6370,6 +6438,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) > case IORING_OP_SYMLINKAT: > ret = io_symlinkat(req, issue_flags); > break; > + case IORING_OP_LINKAT: > + ret = io_linkat(req, issue_flags); > + break; > default: > ret = -EINVAL; > break; > diff --git a/fs/namei.c b/fs/namei.c > index f5b0379d2f8c..b85e457c43b7 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -4356,7 +4356,7 @@ EXPORT_SYMBOL(vfs_link); > * with linux 2.0, and to avoid hard-linking to directories > * and other special files. --ADM > */ > -static int do_linkat(int olddfd, struct filename *old, int newdfd, > +int do_linkat(int olddfd, struct filename *old, int newdfd, > struct filename *new, int flags) > { > struct user_namespace *mnt_userns; > diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h > index 796f37ab4ce3..c735fc22e459 100644 > --- a/include/uapi/linux/io_uring.h > +++ b/include/uapi/linux/io_uring.h > @@ -44,6 +44,7 @@ struct io_uring_sqe { > __u32 splice_flags; > __u32 rename_flags; > __u32 unlink_flags; > + __u32 hardlink_flags; > }; > __u64 user_data; /* data to be passed back at completion time */ > union { > @@ -139,6 +140,7 @@ enum { > IORING_OP_UNLINKAT, > IORING_OP_MKDIRAT, > IORING_OP_SYMLINKAT, > + IORING_OP_LINKAT, > > /* this goes last, obviously */ > IORING_OP_LAST, > -- Pavel Begunkov
