From 529565dcb1581c9a1e3f6df1c1763ca3e0f0d512 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 10 Apr 2006 15:18:58 +0200 Subject: [PATCH] [PATCH] splice: add optional input and output offsets add optional input and output offsets to sys_splice(), for seekable file descriptors: asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, int fd_out, loff_t __user *off_out, size_t len, unsigned int flags); semantics are straightforward: f_pos will be updated with the offset provided by user-space, before the splice transfer is about to begin. Providing a NULL offset pointer means the existing f_pos will be used (and updated in situ). Providing an offset for a pipe results in -ESPIPE. Providing an invalid offset pointer results in -EFAULT. Signed-off-by: Ingo Molnar Signed-off-by: Jens Axboe --- fs/splice.c | 54 ++++++++++++++++++++++++++++++---------- include/linux/syscalls.h | 7 ++++-- 2 files changed, 46 insertions(+), 15 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index ed91a62402e0..a5326127aad5 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -680,7 +680,8 @@ EXPORT_SYMBOL(generic_splice_sendpage); * Attempt to initiate a splice from pipe to file. */ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, - size_t len, unsigned int flags) + loff_t __user *off_out, size_t len, + unsigned int flags) { loff_t pos; int ret; @@ -691,7 +692,11 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, if (!(out->f_mode & FMODE_WRITE)) return -EBADF; + if (off_out && copy_from_user(&out->f_pos, off_out, sizeof(loff_t))) + return -EFAULT; + pos = out->f_pos; + ret = rw_verify_area(WRITE, out, &pos, len); if (unlikely(ret < 0)) return ret; @@ -702,8 +707,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, /* * Attempt to initiate a splice from a file to a pipe. */ -static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, - size_t len, unsigned int flags) +static long do_splice_to(struct file *in, loff_t __user *off_in, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { loff_t pos, isize, left; int ret; @@ -714,7 +720,11 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, if (!(in->f_mode & FMODE_READ)) return -EBADF; + if (off_in && copy_from_user(&in->f_pos, off_in, sizeof(loff_t))) + return -EFAULT; + pos = in->f_pos; + ret = rw_verify_area(READ, in, &pos, len); if (unlikely(ret < 0)) return ret; @@ -733,23 +743,39 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, /* * Determine where to splice to/from. */ -static long do_splice(struct file *in, struct file *out, size_t len, - unsigned int flags) +static long do_splice(struct file *in, loff_t __user *off_in, + struct file *out, loff_t __user *off_out, + size_t len, unsigned int flags) { struct pipe_inode_info *pipe; + if (off_out && out->f_op->llseek == no_llseek) + return -EINVAL; + if (off_in && in->f_op->llseek == no_llseek) + return -EINVAL; + pipe = in->f_dentry->d_inode->i_pipe; - if (pipe) - return do_splice_from(pipe, out, len, flags); + if (pipe) { + if (off_in) + return -ESPIPE; + + return do_splice_from(pipe, out, off_out, len, flags); + } pipe = out->f_dentry->d_inode->i_pipe; - if (pipe) - return do_splice_to(in, pipe, len, flags); + if (pipe) { + if (off_out) + return -ESPIPE; + + return do_splice_to(in, off_in, pipe, len, flags); + } return -EINVAL; } -asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags) +asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, + int fd_out, loff_t __user *off_out, + size_t len, unsigned int flags) { long error; struct file *in, *out; @@ -759,13 +785,15 @@ asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags) return 0; error = -EBADF; - in = fget_light(fdin, &fput_in); + in = fget_light(fd_in, &fput_in); if (in) { if (in->f_mode & FMODE_READ) { - out = fget_light(fdout, &fput_out); + out = fget_light(fd_out, &fput_out); if (out) { if (out->f_mode & FMODE_WRITE) - error = do_splice(in, out, len, flags); + error = do_splice(in, off_in, + out, off_out, + len, flags); fput_light(out, fput_out); } } diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 5717147596b6..4c292faa70c9 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -569,8 +569,11 @@ asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user * filename, asmlinkage long compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int mode); asmlinkage long sys_unshare(unsigned long unshare_flags); -asmlinkage long sys_splice(int fdin, int fdout, size_t len, - unsigned int flags); + +asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, + int fd_out, loff_t __user *off_out, + size_t len, unsigned int flags); + asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes, int flags); -- 2.39.2