X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Frelay.c;h=ad855017bc59de72ebf592fda7576edf6e245bb4;hb=ea0b7d5da0024df1c6f2c2139dbeb4fd260baac6;hp=951f29b24e5880a22043066270828a2012218cbe;hpb=d6b29d7cee064f28ca097e906de7453541351095;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/relay.c b/kernel/relay.c
index 951f29b24e5..ad855017bc5 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1,7 +1,7 @@
 /*
  * Public API and common code for kernel->userspace relay file support.
  *
- * See Documentation/filesystems/relayfs.txt for an overview of relayfs.
+ * See Documentation/filesystems/relay.txt for an overview.
  *
  * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
  * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
@@ -80,7 +80,7 @@ static struct vm_operations_struct relay_file_mmap_ops = {
  *
  *	Caller should already have grabbed mmap_sem.
  */
-int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
+static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
 {
 	unsigned long length = vma->vm_end - vma->vm_start;
 	struct file *filp = vma->vm_file;
@@ -145,7 +145,7 @@ depopulate:
  *
  *	Returns channel buffer if successful, %NULL otherwise.
  */
-struct rchan_buf *relay_create_buf(struct rchan *chan)
+static struct rchan_buf *relay_create_buf(struct rchan *chan)
 {
 	struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
 	if (!buf)
@@ -175,7 +175,7 @@ free_buf:
  *
  *	Should only be called from kref_put().
  */
-void relay_destroy_channel(struct kref *kref)
+static void relay_destroy_channel(struct kref *kref)
 {
 	struct rchan *chan = container_of(kref, struct rchan, kref);
 	kfree(chan);
@@ -185,7 +185,7 @@ void relay_destroy_channel(struct kref *kref)
  *	relay_destroy_buf - destroy an rchan_buf struct and associated buffer
  *	@buf: the buffer struct
  */
-void relay_destroy_buf(struct rchan_buf *buf)
+static void relay_destroy_buf(struct rchan_buf *buf)
 {
 	struct rchan *chan = buf->chan;
 	unsigned int i;
@@ -210,7 +210,7 @@ void relay_destroy_buf(struct rchan_buf *buf)
  *	rchan_buf_struct and the channel buffer.  Should only be called from
  *	kref_put().
  */
-void relay_remove_buf(struct kref *kref)
+static void relay_remove_buf(struct kref *kref)
 {
 	struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
 	buf->chan->cb->remove_buf_file(buf->dentry);
@@ -223,11 +223,10 @@ void relay_remove_buf(struct kref *kref)
  *
  *	Returns 1 if the buffer is empty, 0 otherwise.
  */
-int relay_buf_empty(struct rchan_buf *buf)
+static int relay_buf_empty(struct rchan_buf *buf)
 {
 	return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1;
 }
-EXPORT_SYMBOL_GPL(relay_buf_empty);
 
 /**
  *	relay_buf_full - boolean, is the channel buffer full?
@@ -427,6 +426,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
 
 free_buf:
  	relay_destroy_buf(buf);
+ 	buf = NULL;
 free_name:
  	kfree(tmpname);
 end:
@@ -1032,32 +1032,36 @@ static ssize_t relay_file_read(struct file *filp,
 				       NULL, &desc);
 }
 
+static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed)
+{
+	rbuf->bytes_consumed += bytes_consumed;
+
+	if (rbuf->bytes_consumed >= rbuf->chan->subbuf_size) {
+		relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1);
+		rbuf->bytes_consumed %= rbuf->chan->subbuf_size;
+	}
+}
+
 static void relay_pipe_buf_release(struct pipe_inode_info *pipe,
 				   struct pipe_buffer *buf)
 {
 	struct rchan_buf *rbuf;
 
 	rbuf = (struct rchan_buf *)page_private(buf->page);
-
-	rbuf->bytes_consumed += PAGE_SIZE;
-
-	if (rbuf->bytes_consumed == rbuf->chan->subbuf_size) {
-		relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1);
-		rbuf->bytes_consumed = 0;
-	}
+	relay_consume_bytes(rbuf, buf->private);
 }
 
 static struct pipe_buf_operations relay_pipe_buf_ops = {
 	.can_merge = 0,
 	.map = generic_pipe_buf_map,
 	.unmap = generic_pipe_buf_unmap,
-	.pin = generic_pipe_buf_pin,
+	.confirm = generic_pipe_buf_confirm,
 	.release = relay_pipe_buf_release,
 	.steal = generic_pipe_buf_steal,
 	.get = generic_pipe_buf_get,
 };
 
-/**
+/*
  *	subbuf_splice_actor - splice up to one subbuf's worth of data
  */
 static int subbuf_splice_actor(struct file *in,
@@ -1067,118 +1071,81 @@ static int subbuf_splice_actor(struct file *in,
 			       unsigned int flags,
 			       int *nonpad_ret)
 {
-	unsigned int pidx, poff;
-	unsigned int subbuf_pages;
-	int ret = 0;
-	int do_wakeup = 0;
+	unsigned int pidx, poff, total_len, subbuf_pages, ret;
 	struct rchan_buf *rbuf = in->private_data;
 	unsigned int subbuf_size = rbuf->chan->subbuf_size;
-	size_t read_start = ((size_t)*ppos) % rbuf->chan->alloc_size;
-	size_t avail = subbuf_size - read_start % subbuf_size;
+	uint64_t pos = (uint64_t) *ppos;
+	uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size;
+	size_t read_start = (size_t) do_div(pos, alloc_size);
 	size_t read_subbuf = read_start / subbuf_size;
 	size_t padding = rbuf->padding[read_subbuf];
 	size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding;
+	struct page *pages[PIPE_BUFFERS];
+	struct partial_page partial[PIPE_BUFFERS];
+	struct splice_pipe_desc spd = {
+		.pages = pages,
+		.nr_pages = 0,
+		.partial = partial,
+		.flags = flags,
+		.ops = &relay_pipe_buf_ops,
+	};
 
 	if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
 		return 0;
 
-	if (len > avail)
-		len = avail;
-
-	if (pipe->inode)
-		mutex_lock(&pipe->inode->i_mutex);
+	/*
+	 * Adjust read len, if longer than what is available
+	 */
+	if (len > (subbuf_size - read_start % subbuf_size))
+		len = subbuf_size - read_start % subbuf_size;
 
 	subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
 	pidx = (read_start / PAGE_SIZE) % subbuf_pages;
 	poff = read_start & ~PAGE_MASK;
 
-	for (;;) {
-		unsigned int this_len;
-		unsigned int this_end;
-		int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1);
-		struct pipe_buffer *buf = pipe->bufs + newbuf;
+	for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) {
+		unsigned int this_len, this_end, private;
+		unsigned int cur_pos = read_start + total_len;
 
-		if (!pipe->readers) {
-			send_sig(SIGPIPE, current, 0);
-			if (!ret)
-				ret = -EPIPE;
+		if (!len)
 			break;
-		}
-
-		if (pipe->nrbufs < PIPE_BUFFERS) {
-			this_len = PAGE_SIZE - poff;
-			if (this_len > avail)
-				this_len = avail;
-
-			buf->page = rbuf->page_array[pidx];
-			buf->offset = poff;
-			this_end = read_start + ret + this_len;
-			if (this_end > nonpad_end) {
-				if (read_start + ret >= nonpad_end)
-					buf->len = 0;
-				else
-					buf->len = nonpad_end - (read_start + ret);
-			} else
-				buf->len = this_len;
-
-			*nonpad_ret += buf->len;
 
-			buf->ops = &relay_pipe_buf_ops;
-			pipe->nrbufs++;
+		this_len = min_t(unsigned long, len, PAGE_SIZE - poff);
+		private = this_len;
 
-			avail -= this_len;
-			ret += this_len;
-			poff = 0;
-			pidx = (pidx + 1) % subbuf_pages;
+		spd.pages[spd.nr_pages] = rbuf->page_array[pidx];
+		spd.partial[spd.nr_pages].offset = poff;
 
-			if (pipe->inode)
-				do_wakeup = 1;
-
-			if (!avail)
-				break;
-
-			if (pipe->nrbufs < PIPE_BUFFERS)
-				continue;
-
-			break;
+		this_end = cur_pos + this_len;
+		if (this_end >= nonpad_end) {
+			this_len = nonpad_end - cur_pos;
+			private = this_len + padding;
 		}
+		spd.partial[spd.nr_pages].len = this_len;
+		spd.partial[spd.nr_pages].private = private;
 
-		if (flags & SPLICE_F_NONBLOCK) {
-			if (!ret)
-				ret = -EAGAIN;
-			break;
-		}
+		len -= this_len;
+		total_len += this_len;
+		poff = 0;
+		pidx = (pidx + 1) % subbuf_pages;
 
-		if (signal_pending(current)) {
-			if (!ret)
-				ret = -ERESTARTSYS;
+		if (this_end >= nonpad_end) {
+			spd.nr_pages++;
 			break;
 		}
-
-		if (do_wakeup) {
-			smp_mb();
-			if (waitqueue_active(&pipe->wait))
-				wake_up_interruptible_sync(&pipe->wait);
-			kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
-			do_wakeup = 0;
-		}
-
-		pipe->waiting_writers++;
-		pipe_wait(pipe);
-		pipe->waiting_writers--;
 	}
 
-	if (pipe->inode)
-		mutex_unlock(&pipe->inode->i_mutex);
+	if (!spd.nr_pages)
+		return 0;
 
-	if (do_wakeup) {
-		smp_mb();
-		if (waitqueue_active(&pipe->wait))
-			wake_up_interruptible(&pipe->wait);
-		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
-	}
+	ret = *nonpad_ret = splice_to_pipe(pipe, &spd);
+	if (ret < 0 || ret < total_len)
+		return ret;
 
-	return ret;
+        if (read_start + ret == nonpad_end)
+                ret += padding;
+
+        return ret;
 }
 
 static ssize_t relay_file_splice_read(struct file *in,
@@ -1199,7 +1166,6 @@ static ssize_t relay_file_splice_read(struct file *in,
 		if (ret < 0)
 			break;
 		else if (!ret) {
-			break;
 			if (spliced)
 				break;
 			if (flags & SPLICE_F_NONBLOCK) {