[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 <mingo@elte.hu>
Signed-off-by: Jens Axboe <axboe@suse.de>
This commit is contained in:
Ingo Molnar 2006-04-10 15:18:58 +02:00 committed by Jens Axboe
parent 3a326a2ce8
commit 529565dcb1
2 changed files with 46 additions and 15 deletions

View file

@ -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);