diff options
| -rw-r--r-- | fs/splice.c | 144 |
1 files changed, 75 insertions, 69 deletions
diff --git a/fs/splice.c b/fs/splice.c index 005d09cf3fa8..e3d0ae5383e7 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1242,38 +1242,26 @@ static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, * For lack of a better implementation, implement vmsplice() to userspace * as a simple copy of the pipes pages to the user iov. */ -static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov, - unsigned long nr_segs, unsigned int flags) +static long vmsplice_to_user(struct file *file, struct iov_iter *iter, + unsigned int flags) { - struct pipe_inode_info *pipe; - struct splice_desc sd; - long ret; - struct iovec iovstack[UIO_FASTIOV]; - struct iovec *iov = iovstack; - struct iov_iter iter; + struct pipe_inode_info *pipe = get_pipe_info(file); + struct splice_desc sd = { + .total_len = iov_iter_count(iter), + .flags = flags, + .u.data = iter + }; + long ret = 0; - pipe = get_pipe_info(file); if (!pipe) return -EBADF; - ret = import_iovec(READ, uiov, nr_segs, - ARRAY_SIZE(iovstack), &iov, &iter); - if (ret < 0) - return ret; - - sd.total_len = iov_iter_count(&iter); - sd.len = 0; - sd.flags = flags; - sd.u.data = &iter; - sd.pos = 0; - if (sd.total_len) { pipe_lock(pipe); ret = __splice_from_pipe(pipe, &sd, pipe_to_user); pipe_unlock(pipe); } - kfree(iov); return ret; } @@ -1282,14 +1270,11 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov, * as splice-from-memory, where the regular splice is splice-from-file (or * to file). In both cases the output is a pipe, naturally. */ -static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov, - unsigned long nr_segs, unsigned int flags) +static long vmsplice_to_pipe(struct file *file, struct iov_iter *iter, + unsigned int flags) { struct pipe_inode_info *pipe; - struct iovec iovstack[UIO_FASTIOV]; - struct iovec *iov = iovstack; - struct iov_iter from; - long ret; + long ret = 0; unsigned buf_flag = 0; if (flags & SPLICE_F_GIFT) @@ -1299,22 +1284,31 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov, if (!pipe) return -EBADF; - ret = import_iovec(WRITE, uiov, nr_segs, - ARRAY_SIZE(iovstack), &iov, &from); - if (ret < 0) - return ret; - pipe_lock(pipe); ret = wait_for_space(pipe, flags); if (!ret) - ret = iter_to_pipe(&from, pipe, buf_flag); + ret = iter_to_pipe(iter, pipe, buf_flag); pipe_unlock(pipe); if (ret > 0) wakeup_pipe_readers(pipe); - kfree(iov); return ret; } +static int vmsplice_type(struct fd f, int *type) +{ + if (!f.file) + return -EBADF; + if (f.file->f_mode & FMODE_WRITE) { + *type = WRITE; + } else if (f.file->f_mode & FMODE_READ) { + *type = READ; + } else { + fdput(f); + return -EBADF; + } + return 0; +} + /* * Note that vmsplice only really supports true splicing _from_ user memory * to a pipe, not the other way around. Splicing from user memory is a simple @@ -1331,57 +1325,69 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov, * Currently we punt and implement it as a normal copy, see pipe_to_user(). * */ -static long do_vmsplice(int fd, const struct iovec __user *iov, - unsigned long nr_segs, unsigned int flags) +static long do_vmsplice(struct file *f, struct iov_iter *iter, unsigned int flags) { - struct fd f; - long error; - if (unlikely(flags & ~SPLICE_F_ALL)) return -EINVAL; - if (unlikely(nr_segs > UIO_MAXIOV)) - return -EINVAL; - else if (unlikely(!nr_segs)) - return 0; - error = -EBADF; - f = fdget(fd); - if (f.file) { - if (f.file->f_mode & FMODE_WRITE) - error = vmsplice_to_pipe(f.file, iov, nr_segs, flags); - else if (f.file->f_mode & FMODE_READ) - error = vmsplice_to_user(f.file, iov, nr_segs, flags); - - fdput(f); - } + if (!iov_iter_count(iter)) + return 0; - return error; + if (iov_iter_rw(iter) == WRITE) + return vmsplice_to_pipe(f, iter, flags); + else + return vmsplice_to_user(f, iter, flags); } -SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov, +SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov, unsigned long, nr_segs, unsigned int, flags) { - return do_vmsplice(fd, iov, nr_segs, flags); + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + struct iov_iter iter; + long error; + struct fd f; + int type; + + f = fdget(fd); + error = vmsplice_type(f, &type); + if (error) + return error; + + error = import_iovec(type, uiov, nr_segs, + ARRAY_SIZE(iovstack), &iov, &iter); + if (!error) { + error = do_vmsplice(f.file, &iter, flags); + kfree(iov); + } + fdput(f); + return error; } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32, unsigned int, nr_segs, unsigned int, flags) { - unsigned i; - struct iovec __user *iov; - if (nr_segs > UIO_MAXIOV) - return -EINVAL; - iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec)); - for (i = 0; i < nr_segs; i++) { - struct compat_iovec v; - if (get_user(v.iov_base, &iov32[i].iov_base) || - get_user(v.iov_len, &iov32[i].iov_len) || - put_user(compat_ptr(v.iov_base), &iov[i].iov_base) || - put_user(v.iov_len, &iov[i].iov_len)) - return -EFAULT; + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + struct iov_iter iter; + long error; + struct fd f; + int type; + + f = fdget(fd); + error = vmsplice_type(f, &type); + if (error) + return error; + + error = compat_import_iovec(type, iov32, nr_segs, + ARRAY_SIZE(iovstack), &iov, &iter); + if (!error) { + error = do_vmsplice(f.file, &iter, flags); + kfree(iov); } - return do_vmsplice(fd, iov, nr_segs, flags); + fdput(f); + return error; } #endif |