vmsplice(): lift importing iovec into vmsplice(2) and compat counterpart
... getting rid of transformations in the latter - just use compat_import_iovec(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
4faa99965e
commit
87a3002af9
144
fs/splice.c
144
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))
|
||||
|
||||
if (!iov_iter_count(iter))
|
||||
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);
|
||||
}
|
||||
|
||||
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
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue