sd->len, &pos, more);
}
-/*
- * This is a little more tricky than the file -> pipe splicing. There are
- * basically three cases:
- *
- * - Destination page already exists in the address space and there
- * are users of it. For that case we have no other option that
- * copying the data. Tough luck.
- * - Destination page already exists in the address space, but there
- * are no users of it. Make sure it's uptodate, then drop it. Fall
- * through to last case.
- * - Destination page does not exist, we can add the pipe page to
- * the page cache and avoid the copy.
- *
- * If asked to move pages to the output file (SPLICE_F_MOVE is set in
- * sd->flags), we attempt to migrate pages from the pipe to the output
- * file address space page cache. This is possible if no one else has
- * the pipe page referenced outside of the pipe and page cache. If
- * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create
- * a new page in the output file page cache and fill/dirty that.
- */
-int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
- struct splice_desc *sd)
-{
- struct file *file = sd->u.file;
- struct address_space *mapping = file->f_mapping;
- unsigned int offset, this_len;
- struct page *page;
- void *fsdata;
- int ret;
-
- offset = sd->pos & ~PAGE_CACHE_MASK;
-
- this_len = sd->len;
- if (this_len + offset > PAGE_CACHE_SIZE)
- this_len = PAGE_CACHE_SIZE - offset;
-
- ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
- AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
- if (unlikely(ret))
- goto out;
-
- if (buf->page != page) {
- char *src = kmap_atomic(buf->page);
- char *dst = kmap_atomic(page);
-
- memcpy(dst + offset, src + buf->offset, this_len);
- flush_dcache_page(page);
- kunmap_atomic(dst);
- kunmap_atomic(src);
- }
- ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
- page, fsdata);
-out:
- return ret;
-}
-EXPORT_SYMBOL(pipe_to_file);
-
static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
{
smp_mb();
* locking is required around copying the pipe buffers to the
* destination.
*/
-int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
+static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
splice_actor *actor)
{
int ret;
return 1;
}
-EXPORT_SYMBOL(splice_from_pipe_feed);
/**
* splice_from_pipe_next - wait for some data to splice from
* value (one) if pipe buffers are available. It will return zero
* or -errno if no more data needs to be spliced.
*/
-int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
+static int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
{
while (!pipe->nrbufs) {
if (!pipe->writers)
return 1;
}
-EXPORT_SYMBOL(splice_from_pipe_next);
/**
* splice_from_pipe_begin - start splicing from pipe
* splice_from_pipe_next() and splice_from_pipe_feed() to
* initialize the necessary fields of @sd.
*/
-void splice_from_pipe_begin(struct splice_desc *sd)
+static void splice_from_pipe_begin(struct splice_desc *sd)
{
sd->num_spliced = 0;
sd->need_wakeup = false;
}
-EXPORT_SYMBOL(splice_from_pipe_begin);
/**
* splice_from_pipe_end - finish splicing from pipe
* be called after a loop containing splice_from_pipe_next() and
* splice_from_pipe_feed().
*/
-void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
+static void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
{
if (sd->need_wakeup)
wakeup_pipe_writers(pipe);
}
-EXPORT_SYMBOL(splice_from_pipe_end);
/**
* __splice_from_pipe - splice data from a pipe to given actor
return ret;
}
-/**
- * generic_file_splice_write - splice data from a pipe to a file
- * @pipe: pipe info
- * @out: file to write to
- * @ppos: position in @out
- * @len: number of bytes to splice
- * @flags: splice modifier flags
- *
- * Description:
- * Will either move or copy pages (determined by @flags options) from
- * the given pipe inode to the given file.
- *
- */
-ssize_t
-generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
- loff_t *ppos, size_t len, unsigned int flags)
-{
- struct address_space *mapping = out->f_mapping;
- struct inode *inode = mapping->host;
- struct splice_desc sd = {
- .total_len = len,
- .flags = flags,
- .pos = *ppos,
- .u.file = out,
- };
- ssize_t ret;
-
- pipe_lock(pipe);
-
- splice_from_pipe_begin(&sd);
- do {
- ret = splice_from_pipe_next(pipe, &sd);
- if (ret <= 0)
- break;
-
- mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
- ret = file_remove_suid(out);
- if (!ret) {
- ret = file_update_time(out);
- if (!ret)
- ret = splice_from_pipe_feed(pipe, &sd,
- pipe_to_file);
- }
- mutex_unlock(&inode->i_mutex);
- } while (ret > 0);
- splice_from_pipe_end(pipe, &sd);
-
- pipe_unlock(pipe);
-
- if (sd.num_spliced)
- ret = sd.num_spliced;
-
- if (ret > 0) {
- int err;
-
- err = generic_write_sync(out, *ppos, ret);
- if (err)
- ret = err;
- else
- *ppos += ret;
- balance_dirty_pages_ratelimited(mapping);
- }
-
- return ret;
-}
-
-EXPORT_SYMBOL(generic_file_splice_write);
-
/**
* iter_file_splice_write - splice data from a pipe to a file
* @pipe: pipe info
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
struct iov_iter iter;
- ssize_t count = 0;
+ ssize_t count;
pipe = get_pipe_info(file);
if (!pipe)
ret = rw_copy_check_uvector(READ, uiov, nr_segs,
ARRAY_SIZE(iovstack), iovstack, &iov);
if (ret <= 0)
- return ret;
+ goto out;
+ count = ret;
iov_iter_init(&iter, READ, iov, nr_segs, count);
sd.len = 0;
ret = __splice_from_pipe(pipe, &sd, pipe_to_user);
pipe_unlock(pipe);
+out:
if (iov != iovstack)
kfree(iov);
projects / firefly-linux-kernel-4.4.55.git / blobdiff