#include <linux/gfp.h>
#include <linux/socket.h>
#include <linux/compat.h>
+#include <linux/aio.h>
#include "internal.h"
/*
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
}
/**
- * generic_file_splice_write - splice data from a pipe to a file
+ * iter_file_splice_write - splice data from a pipe to a file
* @pipe: pipe info
* @out: file to write to
* @ppos: position in @out
* Description:
* Will either move or copy pages (determined by @flags options) from
* the given pipe inode to the given file.
+ * This one is ->write_iter-based.
*
*/
ssize_t
-generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
+iter_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,
};
+ int nbufs = pipe->buffers;
+ struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),
+ GFP_KERNEL);
ssize_t ret;
+ if (unlikely(!array))
+ return -ENOMEM;
+
pipe_lock(pipe);
splice_from_pipe_begin(&sd);
- do {
+ while (sd.total_len) {
+ struct iov_iter from;
+ struct kiocb kiocb;
+ size_t left;
+ int n, idx;
+
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);
+ if (unlikely(nbufs < pipe->buffers)) {
+ kfree(array);
+ nbufs = pipe->buffers;
+ array = kcalloc(nbufs, sizeof(struct bio_vec),
+ GFP_KERNEL);
+ if (!array) {
+ ret = -ENOMEM;
+ break;
+ }
}
- mutex_unlock(&inode->i_mutex);
- } while (ret > 0);
+
+ /* build the vector */
+ left = sd.total_len;
+ for (n = 0, idx = pipe->curbuf; left && n < pipe->nrbufs; n++, idx++) {
+ struct pipe_buffer *buf = pipe->bufs + idx;
+ size_t this_len = buf->len;
+
+ if (this_len > left)
+ this_len = left;
+
+ if (idx == pipe->buffers - 1)
+ idx = -1;
+
+ ret = buf->ops->confirm(pipe, buf);
+ if (unlikely(ret)) {
+ if (ret == -ENODATA)
+ ret = 0;
+ goto done;
+ }
+
+ array[n].bv_page = buf->page;
+ array[n].bv_len = this_len;
+ array[n].bv_offset = buf->offset;
+ left -= this_len;
+ }
+
+ /* ... iov_iter */
+ from.type = ITER_BVEC | WRITE;
+ from.bvec = array;
+ from.nr_segs = n;
+ from.count = sd.total_len - left;
+ from.iov_offset = 0;
+
+ /* ... and iocb */
+ init_sync_kiocb(&kiocb, out);
+ kiocb.ki_pos = sd.pos;
+ kiocb.ki_nbytes = sd.total_len - left;
+
+ /* now, send it */
+ ret = out->f_op->write_iter(&kiocb, &from);
+ if (-EIOCBQUEUED == ret)
+ ret = wait_on_sync_kiocb(&kiocb);
+
+ if (ret <= 0)
+ break;
+
+ sd.num_spliced += ret;
+ sd.total_len -= ret;
+ *ppos = sd.pos = kiocb.ki_pos;
+
+ /* dismiss the fully eaten buffers, adjust the partial one */
+ while (ret) {
+ struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
+ if (ret >= buf->len) {
+ const struct pipe_buf_operations *ops = buf->ops;
+ ret -= buf->len;
+ buf->len = 0;
+ buf->ops = NULL;
+ ops->release(pipe, buf);
+ pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
+ pipe->nrbufs--;
+ if (pipe->files)
+ sd.need_wakeup = true;
+ } else {
+ buf->offset += ret;
+ buf->len -= ret;
+ ret = 0;
+ }
+ }
+ }
+done:
+ kfree(array);
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);
+EXPORT_SYMBOL(iter_file_splice_write);
static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
struct splice_desc *sd)
goto out;
count = ret;
- iov_iter_init(&iter, iov, nr_segs, count, 0);
+ iov_iter_init(&iter, READ, iov, nr_segs, count);
sd.len = 0;
sd.total_len = count;
projects / karo-tx-linux.git / blobdiff