#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/gfp.h>
+#include <linux/net.h>
#include <linux/socket.h>
#include <linux/sched/signal.h>
kfree(spd->partial);
}
-/*
- * Splice data from an O_DIRECT file into pages and then add them to the output
- * pipe.
+/**
+ * copy_splice_read - Copy data from a file and splice the copy into a pipe
+ * @in: The file to read from
+ * @ppos: Pointer to the file position to read from
+ * @pipe: The pipe to splice into
+ * @len: The amount to splice
+ * @flags: The SPLICE_F_* flags
+ *
+ * This function allocates a bunch of pages sufficient to hold the requested
+ * amount of data (but limited by the remaining pipe capacity), passes it to
+ * the file's ->read_iter() to read into and then splices the used pages into
+ * the pipe.
+ *
+ * Return: On success, the number of bytes read will be returned and *@ppos
+ * will be updated if appropriate; 0 will be returned if there is no more data
+ * to be read; -EAGAIN will be returned if the pipe had no space, and some
+ * other negative error code will be returned on error. A short read may occur
+ * if the pipe has insufficient space, we reach the end of the data or we hit a
+ * hole.
*/
-ssize_t direct_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe,
- size_t len, unsigned int flags)
+ssize_t copy_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags)
{
struct iov_iter to;
struct bio_vec *bv;
struct kiocb kiocb;
struct page **pages;
ssize_t ret;
- size_t used, npages, chunk, remain, reclaim;
+ size_t used, npages, chunk, remain, keep = 0;
int i;
/* Work out how much data we can actually add into the pipe */
if (!bv)
return -ENOMEM;
- pages = (void *)(bv + npages);
+ pages = (struct page **)(bv + npages);
npages = alloc_pages_bulk_array(GFP_USER, npages, pages);
if (!npages) {
kfree(bv);
kiocb.ki_pos = *ppos;
ret = call_read_iter(in, &kiocb, &to);
- reclaim = npages * PAGE_SIZE;
- remain = 0;
if (ret > 0) {
- reclaim -= ret;
- remain = ret;
+ keep = DIV_ROUND_UP(ret, PAGE_SIZE);
*ppos = kiocb.ki_pos;
- file_accessed(in);
- } else if (ret < 0) {
- /*
- * callers of ->splice_read() expect -EAGAIN on
- * "can't put anything in there", rather than -EFAULT.
- */
- if (ret == -EFAULT)
- ret = -EAGAIN;
}
+ /*
+ * Callers of ->splice_read() expect -EAGAIN on "can't put anything in
+ * there", rather than -EFAULT.
+ */
+ if (ret == -EFAULT)
+ ret = -EAGAIN;
+
/* Free any pages that didn't get touched at all. */
- reclaim /= PAGE_SIZE;
- if (reclaim) {
- npages -= reclaim;
- release_pages(pages + npages, reclaim);
- }
+ if (keep < npages)
+ release_pages(pages + keep, npages - keep);
/* Push the remaining pages into the pipe. */
- for (i = 0; i < npages; i++) {
+ remain = ret;
+ for (i = 0; i < keep; i++) {
struct pipe_buffer *buf = pipe_head_buf(pipe);
chunk = min_t(size_t, remain, PAGE_SIZE);
kfree(bv);
return ret;
}
-EXPORT_SYMBOL(direct_splice_read);
-
-/**
- * generic_file_splice_read - splice data from file to a pipe
- * @in: file to splice from
- * @ppos: position in @in
- * @pipe: pipe to splice to
- * @len: number of bytes to splice
- * @flags: splice modifier flags
- *
- * Description:
- * Will read pages from given file and fill them into a pipe. Can be
- * used as long as it has more or less sane ->read_iter().
- *
- */
-ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
-{
- struct iov_iter to;
- struct kiocb kiocb;
- int ret;
-
- iov_iter_pipe(&to, ITER_DEST, pipe, len);
- init_sync_kiocb(&kiocb, in);
- kiocb.ki_pos = *ppos;
- ret = call_read_iter(in, &kiocb, &to);
- if (ret > 0) {
- *ppos = kiocb.ki_pos;
- file_accessed(in);
- } else if (ret < 0) {
- /* free what was emitted */
- pipe_discard_from(pipe, to.start_head);
- /*
- * callers of ->splice_read() expect -EAGAIN on
- * "can't put anything in there", rather than -EFAULT.
- */
- if (ret == -EFAULT)
- ret = -EAGAIN;
- }
-
- return ret;
-}
-EXPORT_SYMBOL(generic_file_splice_read);
+EXPORT_SYMBOL(copy_splice_read);
const struct pipe_buf_operations default_pipe_buf_ops = {
.release = generic_pipe_buf_release,
};
EXPORT_SYMBOL(nosteal_pipe_buf_ops);
-/*
- * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
- * using sendpage(). Return the number of bytes sent.
- */
-static int pipe_to_sendpage(struct pipe_inode_info *pipe,
- struct pipe_buffer *buf, struct splice_desc *sd)
-{
- struct file *file = sd->u.file;
- loff_t pos = sd->pos;
- int more;
-
- if (!likely(file->f_op->sendpage))
- return -EINVAL;
-
- more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
-
- if (sd->len < sd->total_len &&
- pipe_occupancy(pipe->head, pipe->tail) > 1)
- more |= MSG_SENDPAGE_NOTLAST;
-
- return file->f_op->sendpage(file, buf->page, buf->offset,
- sd->len, &pos, more);
-}
-
static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
{
smp_mb();
* Description:
* This function does little more than loop over the pipe and call
* @actor to do the actual moving of a single struct pipe_buffer to
- * the desired destination. See pipe_to_file, pipe_to_sendpage, or
+ * the desired destination. See pipe_to_file, pipe_to_sendmsg, or
* pipe_to_user.
*
*/
EXPORT_SYMBOL(iter_file_splice_write);
+#ifdef CONFIG_NET
/**
- * generic_splice_sendpage - splice data from a pipe to a socket
+ * splice_to_socket - splice data from a pipe to a socket
* @pipe: pipe to splice from
* @out: socket to write to
* @ppos: position in @out
* is involved.
*
*/
-ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
- loff_t *ppos, size_t len, unsigned int flags)
+ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out,
+ loff_t *ppos, size_t len, unsigned int flags)
{
- return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
-}
+ struct socket *sock = sock_from_file(out);
+ struct bio_vec bvec[16];
+ struct msghdr msg = {};
+ ssize_t ret = 0;
+ size_t spliced = 0;
+ bool need_wakeup = false;
+
+ pipe_lock(pipe);
-EXPORT_SYMBOL(generic_splice_sendpage);
+ while (len > 0) {
+ unsigned int head, tail, mask, bc = 0;
+ size_t remain = len;
+
+ /*
+ * Check for signal early to make process killable when there
+ * are always buffers available
+ */
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+
+ while (pipe_empty(pipe->head, pipe->tail)) {
+ ret = 0;
+ if (!pipe->writers)
+ goto out;
+
+ if (spliced)
+ goto out;
+
+ ret = -EAGAIN;
+ if (flags & SPLICE_F_NONBLOCK)
+ goto out;
+
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ goto out;
+
+ if (need_wakeup) {
+ wakeup_pipe_writers(pipe);
+ need_wakeup = false;
+ }
+
+ pipe_wait_readable(pipe);
+ }
+
+ head = pipe->head;
+ tail = pipe->tail;
+ mask = pipe->ring_size - 1;
+
+ while (!pipe_empty(head, tail)) {
+ struct pipe_buffer *buf = &pipe->bufs[tail & mask];
+ size_t seg;
+
+ if (!buf->len) {
+ tail++;
+ continue;
+ }
+
+ seg = min_t(size_t, remain, buf->len);
+
+ ret = pipe_buf_confirm(pipe, buf);
+ if (unlikely(ret)) {
+ if (ret == -ENODATA)
+ ret = 0;
+ break;
+ }
+
+ bvec_set_page(&bvec[bc++], buf->page, seg, buf->offset);
+ remain -= seg;
+ if (remain == 0 || bc >= ARRAY_SIZE(bvec))
+ break;
+ tail++;
+ }
+
+ if (!bc)
+ break;
+
+ msg.msg_flags = MSG_SPLICE_PAGES;
+ if (flags & SPLICE_F_MORE)
+ msg.msg_flags |= MSG_MORE;
+ if (remain && pipe_occupancy(pipe->head, tail) > 0)
+ msg.msg_flags |= MSG_MORE;
+
+ iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, bvec, bc,
+ len - remain);
+ ret = sock_sendmsg(sock, &msg);
+ if (ret <= 0)
+ break;
+
+ spliced += ret;
+ len -= ret;
+ tail = pipe->tail;
+ while (ret > 0) {
+ struct pipe_buffer *buf = &pipe->bufs[tail & mask];
+ size_t seg = min_t(size_t, ret, buf->len);
+
+ buf->offset += seg;
+ buf->len -= seg;
+ ret -= seg;
+
+ if (!buf->len) {
+ pipe_buf_release(pipe, buf);
+ tail++;
+ }
+ }
+
+ if (tail != pipe->tail) {
+ pipe->tail = tail;
+ if (pipe->files)
+ need_wakeup = true;
+ }
+ }
+
+out:
+ pipe_unlock(pipe);
+ if (need_wakeup)
+ wakeup_pipe_writers(pipe);
+ return spliced ?: ret;
+}
+#endif
static int warn_unsupported(struct file *file, const char *op)
{
}
/*
- * Attempt to initiate a splice from a file to a pipe.
+ * Indicate to the caller that there was a premature EOF when reading from the
+ * source and the caller didn't indicate they would be sending more data after
+ * this.
*/
-static long do_splice_to(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
+static void do_splice_eof(struct splice_desc *sd)
+{
+ if (sd->splice_eof)
+ sd->splice_eof(sd);
+}
+
+/**
+ * vfs_splice_read - Read data from a file and splice it into a pipe
+ * @in: File to splice from
+ * @ppos: Input file offset
+ * @pipe: Pipe to splice to
+ * @len: Number of bytes to splice
+ * @flags: Splice modifier flags (SPLICE_F_*)
+ *
+ * Splice the requested amount of data from the input file to the pipe. This
+ * is synchronous as the caller must hold the pipe lock across the entire
+ * operation.
+ *
+ * If successful, it returns the amount of data spliced, 0 if it hit the EOF or
+ * a hole and a negative error code otherwise.
+ */
+long vfs_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
{
unsigned int p_space;
int ret;
if (unlikely(!(in->f_mode & FMODE_READ)))
return -EBADF;
+ if (!len)
+ return 0;
/* Don't try to read more the pipe has space for. */
p_space = pipe->max_usage - pipe_occupancy(pipe->head, pipe->tail);
if (unlikely(!in->f_op->splice_read))
return warn_unsupported(in, "read");
+ /*
+ * O_DIRECT and DAX don't deal with the pagecache, so we allocate a
+ * buffer, copy into it and splice that into the pipe.
+ */
+ if ((in->f_flags & O_DIRECT) || IS_DAX(in->f_mapping->host))
+ return copy_splice_read(in, ppos, pipe, len, flags);
return in->f_op->splice_read(in, ppos, pipe, len, flags);
}
+EXPORT_SYMBOL_GPL(vfs_splice_read);
/**
* splice_direct_to_actor - splices data directly between two non-pipes
*/
bytes = 0;
len = sd->total_len;
+
+ /* Don't block on output, we have to drain the direct pipe. */
flags = sd->flags;
+ sd->flags &= ~SPLICE_F_NONBLOCK;
/*
- * Don't block on output, we have to drain the direct pipe.
+ * We signal MORE until we've read sufficient data to fulfill the
+ * request and we keep signalling it if the caller set it.
*/
- sd->flags &= ~SPLICE_F_NONBLOCK;
more = sd->flags & SPLICE_F_MORE;
+ sd->flags |= SPLICE_F_MORE;
WARN_ON_ONCE(!pipe_empty(pipe->head, pipe->tail));
size_t read_len;
loff_t pos = sd->pos, prev_pos = pos;
- ret = do_splice_to(in, &pos, pipe, len, flags);
+ ret = vfs_splice_read(in, &pos, pipe, len, flags);
if (unlikely(ret <= 0))
- goto out_release;
+ goto read_failure;
read_len = ret;
sd->total_len = read_len;
/*
- * If more data is pending, set SPLICE_F_MORE
- * If this is the last data and SPLICE_F_MORE was not set
- * initially, clears it.
+ * If we now have sufficient data to fulfill the request then
+ * we clear SPLICE_F_MORE if it was not set initially.
*/
- if (read_len < len)
- sd->flags |= SPLICE_F_MORE;
- else if (!more)
+ if (read_len >= len && !more)
sd->flags &= ~SPLICE_F_MORE;
+
/*
* NOTE: nonblocking mode only applies to the input. We
* must not do the output in nonblocking mode as then we
file_accessed(in);
return bytes;
+read_failure:
+ /*
+ * If the user did *not* set SPLICE_F_MORE *and* we didn't hit that
+ * "use all of len" case that cleared SPLICE_F_MORE, *and* we did a
+ * "->splice_in()" that returned EOF (ie zero) *and* we have sent at
+ * least 1 byte *then* we will also do the ->splice_eof() call.
+ */
+ if (ret == 0 && !more && len > 0 && bytes)
+ do_splice_eof(sd);
out_release:
/*
* If we did an incomplete transfer we must release
sd->flags);
}
+static void direct_file_splice_eof(struct splice_desc *sd)
+{
+ struct file *file = sd->u.file;
+
+ if (file->f_op->splice_eof)
+ file->f_op->splice_eof(file);
+}
+
/**
* do_splice_direct - splices data directly between two files
* @in: file to splice from
.flags = flags,
.pos = *ppos,
.u.file = out,
+ .splice_eof = direct_file_splice_eof,
.opos = opos,
};
long ret;
pipe_lock(opipe);
ret = wait_for_space(opipe, flags);
if (!ret)
- ret = do_splice_to(in, offset, opipe, len, flags);
+ ret = vfs_splice_read(in, offset, opipe, len, flags);
pipe_unlock(opipe);
if (ret > 0)
wakeup_pipe_readers(opipe);
projects / platform / kernel / linux-starfive.git / blobdiff