X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fsplice.c;h=d9ff2be5f46b007810a0711b685fe8867cca86bc;hb=a592f46075d79ff7348e624e7d871dca730e70f2;hp=fa2defa8afcf3d18e2fd8fcebcc0a88f1d12fdac;hpb=94bd217e2d683719ab21a4ac117d8a1b91cbedc9;p=pandora-kernel.git

diff --git a/fs/splice.c b/fs/splice.c
index fa2defa8afcf..d9ff2be5f46b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -31,6 +31,7 @@
 #include <linux/uio.h>
 #include <linux/security.h>
 #include <linux/gfp.h>
+#include <linux/socket.h>
 
 /*
  * Attempt to steal a page from a pipe buffer. This should perhaps go into
@@ -273,13 +274,16 @@ void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
  * Check if we need to grow the arrays holding pages and partial page
  * descriptions.
  */
-int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
+int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
 {
-	if (pipe->buffers <= PIPE_DEF_BUFFERS)
+	unsigned int buffers = ACCESS_ONCE(pipe->buffers);
+
+	spd->nr_pages_max = buffers;
+	if (buffers <= PIPE_DEF_BUFFERS)
 		return 0;
 
-	spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
-	spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
+	spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL);
+	spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL);
 
 	if (spd->pages && spd->partial)
 		return 0;
@@ -289,10 +293,9 @@ int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
 	return -ENOMEM;
 }
 
-void splice_shrink_spd(struct pipe_inode_info *pipe,
-		       struct splice_pipe_desc *spd)
+void splice_shrink_spd(struct splice_pipe_desc *spd)
 {
-	if (pipe->buffers <= PIPE_DEF_BUFFERS)
+	if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
 		return;
 
 	kfree(spd->pages);
@@ -315,6 +318,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 	struct splice_pipe_desc spd = {
 		.pages = pages,
 		.partial = partial,
+		.nr_pages_max = PIPE_DEF_BUFFERS,
 		.flags = flags,
 		.ops = &page_cache_pipe_buf_ops,
 		.spd_release = spd_release_page,
@@ -326,7 +330,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 	index = *ppos >> PAGE_CACHE_SHIFT;
 	loff = *ppos & ~PAGE_CACHE_MASK;
 	req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	nr_pages = min(req_pages, pipe->buffers);
+	nr_pages = min(req_pages, spd.nr_pages_max);
 
 	/*
 	 * Lookup the (hopefully) full range of pages we need.
@@ -497,7 +501,7 @@ fill_it:
 	if (spd.nr_pages)
 		error = splice_to_pipe(pipe, &spd);
 
-	splice_shrink_spd(pipe, &spd);
+	splice_shrink_spd(&spd);
 	return error;
 }
 
@@ -550,6 +554,24 @@ static const struct pipe_buf_operations default_pipe_buf_ops = {
 	.get = generic_pipe_buf_get,
 };
 
+static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
+				    struct pipe_buffer *buf)
+{
+	return 1;
+}
+
+/* Pipe buffer operations for a socket and similar. */
+const struct pipe_buf_operations nosteal_pipe_buf_ops = {
+	.can_merge = 0,
+	.map = generic_pipe_buf_map,
+	.unmap = generic_pipe_buf_unmap,
+	.confirm = generic_pipe_buf_confirm,
+	.release = generic_pipe_buf_release,
+	.steal = generic_pipe_buf_nosteal,
+	.get = generic_pipe_buf_get,
+};
+EXPORT_SYMBOL(nosteal_pipe_buf_ops);
+
 static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 			    unsigned long vlen, loff_t offset)
 {
@@ -598,6 +620,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 	struct splice_pipe_desc spd = {
 		.pages = pages,
 		.partial = partial,
+		.nr_pages_max = PIPE_DEF_BUFFERS,
 		.flags = flags,
 		.ops = &default_pipe_buf_ops,
 		.spd_release = spd_release_page,
@@ -608,8 +631,8 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 
 	res = -ENOMEM;
 	vec = __vec;
-	if (pipe->buffers > PIPE_DEF_BUFFERS) {
-		vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
+	if (spd.nr_pages_max > PIPE_DEF_BUFFERS) {
+		vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL);
 		if (!vec)
 			goto shrink_ret;
 	}
@@ -617,7 +640,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 	offset = *ppos & ~PAGE_CACHE_MASK;
 	nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
-	for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
+	for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) {
 		struct page *page;
 
 		page = alloc_page(GFP_USER);
@@ -665,7 +688,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 shrink_ret:
 	if (vec != __vec)
 		kfree(vec);
-	splice_shrink_spd(pipe, &spd);
+	splice_shrink_spd(&spd);
 	return res;
 
 err:
@@ -691,7 +714,11 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe,
 	if (!likely(file->f_op && file->f_op->sendpage))
 		return -EINVAL;
 
-	more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
+	more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
+
+	if (sd->len < sd->total_len && pipe->nrbufs > 1)
+		more |= MSG_SENDPAGE_NOTLAST;
+
 	return file->f_op->sendpage(file, buf->page, buf->offset,
 				    sd->len, &pos, more);
 }
@@ -845,6 +872,13 @@ EXPORT_SYMBOL(splice_from_pipe_feed);
  */
 int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
 {
+	/*
+	 * Check for signal early to make process killable when there are
+	 * always buffers available
+	 */
+	if (signal_pending(current))
+		return -ERESTARTSYS;
+
 	while (!pipe->nrbufs) {
 		if (!pipe->writers)
 			return 0;
@@ -923,6 +957,7 @@ ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
 
 	splice_from_pipe_begin(sd);
 	do {
+		cond_resched();
 		ret = splice_from_pipe_next(pipe, sd);
 		if (ret > 0)
 			ret = splice_from_pipe_feed(pipe, sd, actor);
@@ -986,13 +1021,17 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 	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;
 
+	ret = generic_write_checks(out, ppos, &len, S_ISBLK(inode->i_mode));
+	if (ret)
+		return ret;
+	sd.total_len = len;
+	sd.pos = *ppos;
+
 	pipe_lock(pipe);
 
 	splice_from_pipe_begin(&sd);
@@ -1085,8 +1124,8 @@ EXPORT_SYMBOL(generic_splice_sendpage);
 /*
  * Attempt to initiate a splice from pipe to file.
  */
-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
-			   loff_t *ppos, size_t len, unsigned int flags)
+long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+		    loff_t *ppos, size_t len, unsigned int flags)
 {
 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
 				loff_t *, size_t, unsigned int);
@@ -1109,13 +1148,14 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 
 	return splice_write(pipe, out, ppos, len, flags);
 }
+EXPORT_SYMBOL(do_splice_from);
 
 /*
  * Attempt to initiate a splice from a file to a pipe.
  */
-static long do_splice_to(struct file *in, loff_t *ppos,
-			 struct pipe_inode_info *pipe, size_t len,
-			 unsigned int flags)
+long do_splice_to(struct file *in, loff_t *ppos,
+		  struct pipe_inode_info *pipe, size_t len,
+		  unsigned int flags)
 {
 	ssize_t (*splice_read)(struct file *, loff_t *,
 			       struct pipe_inode_info *, size_t, unsigned int);
@@ -1135,6 +1175,7 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 
 	return splice_read(in, ppos, pipe, len, flags);
 }
+EXPORT_SYMBOL(do_splice_to);
 
 /**
  * splice_direct_to_actor - splices data directly between two non-pipes
@@ -1156,7 +1197,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 	long ret, bytes;
 	umode_t i_mode;
 	size_t len;
-	int i, flags;
+	int i, flags, more;
 
 	/*
 	 * We require the input being a regular file, as we don't want to
@@ -1199,6 +1240,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 	 * Don't block on output, we have to drain the direct pipe.
 	 */
 	sd->flags &= ~SPLICE_F_NONBLOCK;
+	more = sd->flags & SPLICE_F_MORE;
 
 	while (len) {
 		size_t read_len;
@@ -1211,6 +1253,15 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 		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 (read_len < len)
+			sd->flags |= SPLICE_F_MORE;
+		else if (!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
@@ -1613,6 +1664,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
 	struct splice_pipe_desc spd = {
 		.pages = pages,
 		.partial = partial,
+		.nr_pages_max = PIPE_DEF_BUFFERS,
 		.flags = flags,
 		.ops = &user_page_pipe_buf_ops,
 		.spd_release = spd_release_page,
@@ -1628,13 +1680,13 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
 
 	spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
 					    spd.partial, flags & SPLICE_F_GIFT,
-					    pipe->buffers);
+					    spd.nr_pages_max);
 	if (spd.nr_pages <= 0)
 		ret = spd.nr_pages;
 	else
 		ret = splice_to_pipe(pipe, &spd);
 
-	splice_shrink_spd(pipe, &spd);
+	splice_shrink_spd(&spd);
 	return ret;
 }