X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=fs%2Fsplice.c;h=186fad463c4379280dcfbbd2c5422f5188f46c69;hb=00de00bdad278783b3664ad2969954a707f5944a;hp=5428b0ff3b6fcfebe6abd074cb9719ec48c9dbda;hpb=e0cc09e295f346b7921e921f385fe5213472316a;p=deliverable%2Flinux.git

diff --git a/fs/splice.c b/fs/splice.c
index 5428b0ff3b6f..186fad463c43 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -176,6 +176,7 @@ static const struct pipe_buf_operations user_page_pipe_buf_ops = {
 static ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 			      struct splice_pipe_desc *spd)
 {
+	unsigned int spd_pages = spd->nr_pages;
 	int ret, do_wakeup, page_nr;
 
 	ret = 0;
@@ -254,7 +255,7 @@ static ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
 	}
 
-	while (page_nr < spd->nr_pages)
+	while (page_nr < spd_pages)
 		page_cache_release(spd->pages[page_nr++]);
 
 	return ret;
@@ -272,7 +273,6 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 	struct page *page;
 	pgoff_t index, end_index;
 	loff_t isize;
-	size_t total_len;
 	int error, page_nr;
 	struct splice_pipe_desc spd = {
 		.pages = pages,
@@ -289,18 +289,15 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 		nr_pages = PIPE_BUFFERS;
 
 	/*
-	 * Initiate read-ahead on this page range. however, don't call into
-	 * read-ahead if this is a non-zero offset (we are likely doing small
-	 * chunk splice and the page is already there) for a single page.
+	 * Don't try to 2nd guess the read-ahead logic, call into
+	 * page_cache_readahead() like the page cache reads would do.
 	 */
-	if (!loff || nr_pages > 1)
-		page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages);
+	page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages);
 
 	/*
 	 * Now fill in the holes:
 	 */
 	error = 0;
-	total_len = 0;
 
 	/*
 	 * Lookup the (hopefully) full range of pages we need.
@@ -378,10 +375,11 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 			 * If in nonblock mode then dont block on waiting
 			 * for an in-flight io page
 			 */
-			if (flags & SPLICE_F_NONBLOCK)
-				break;
-
-			lock_page(page);
+			if (flags & SPLICE_F_NONBLOCK) {
+				if (TestSetPageLocked(page))
+					break;
+			} else
+				lock_page(page);
 
 			/*
 			 * page was truncated, stop here. if this isn't the
@@ -416,43 +414,47 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 
 				break;
 			}
+		}
+fill_it:
+		/*
+		 * i_size must be checked after PageUptodate.
+		 */
+		isize = i_size_read(mapping->host);
+		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+		if (unlikely(!isize || index > end_index))
+			break;
+
+		/*
+		 * if this is the last page, see if we need to shrink
+		 * the length and stop
+		 */
+		if (end_index == index) {
+			unsigned int plen;
 
 			/*
-			 * i_size must be checked after ->readpage().
+			 * max good bytes in this page
 			 */
-			isize = i_size_read(mapping->host);
-			end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
-			if (unlikely(!isize || index > end_index))
+			plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+			if (plen <= loff)
 				break;
 
 			/*
-			 * if this is the last page, see if we need to shrink
-			 * the length and stop
+			 * force quit after adding this page
 			 */
-			if (end_index == index) {
-				loff = PAGE_CACHE_SIZE - (isize & ~PAGE_CACHE_MASK);
-				if (total_len + loff > isize)
-					break;
-				/*
-				 * force quit after adding this page
-				 */
-				len = this_len;
-				this_len = min(this_len, loff);
-				loff = 0;
-			}
+			this_len = min(this_len, plen - loff);
+			len = this_len;
 		}
-fill_it:
+
 		partial[page_nr].offset = loff;
 		partial[page_nr].len = this_len;
 		len -= this_len;
-		total_len += this_len;
 		loff = 0;
 		spd.nr_pages++;
 		index++;
 	}
 
 	/*
-	 * Release any pages at the end, if we quit early. 'i' is how far
+	 * Release any pages at the end, if we quit early. 'page_nr' is how far
 	 * we got, 'nr_pages' is how many pages are in the map.
 	 */
 	while (page_nr < nr_pages)
@@ -479,10 +481,18 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
 {
 	ssize_t spliced;
 	int ret;
+	loff_t isize, left;
+
+	isize = i_size_read(in->f_mapping->host);
+	if (unlikely(*ppos >= isize))
+		return 0;
+
+	left = isize - *ppos;
+	if (unlikely(left < len))
+		len = left;
 
 	ret = 0;
 	spliced = 0;
-
 	while (len) {
 		ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
 
@@ -645,7 +655,6 @@ find_page:
 	 * accessed, we are now done!
 	 */
 	mark_page_accessed(page);
-	balance_dirty_pages_ratelimited(mapping);
 out:
 	page_cache_release(page);
 	unlock_page(page);
@@ -803,7 +812,10 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out,
 
 	ret = __splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
 	if (ret > 0) {
+		unsigned long nr_pages;
+
 		*ppos += ret;
+		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
 		/*
 		 * If file or inode is SYNC and we actually wrote some data,
@@ -816,6 +828,7 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out,
 			if (err)
 				ret = err;
 		}
+		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
 	}
 
 	return ret;
@@ -854,7 +867,10 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
 	ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
 	if (ret > 0) {
+		unsigned long nr_pages;
+
 		*ppos += ret;
+		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
 		/*
 		 * If file or inode is SYNC and we actually wrote some data,
@@ -869,6 +885,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 			if (err)
 				ret = err;
 		}
+		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
 	}
 
 	return ret;
@@ -923,7 +940,6 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 			 struct pipe_inode_info *pipe, size_t len,
 			 unsigned int flags)
 {
-	loff_t isize, left;
 	int ret;
 
 	if (unlikely(!in->f_op || !in->f_op->splice_read))
@@ -936,14 +952,6 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 	if (unlikely(ret < 0))
 		return ret;
 
-	isize = i_size_read(in->f_mapping->host);
-	if (unlikely(*ppos >= isize))
-		return 0;
-	
-	left = isize - *ppos;
-	if (unlikely(left < len))
-		len = left;
-
 	return in->f_op->splice_read(in, ppos, pipe, len, flags);
 }
 
@@ -1059,8 +1067,6 @@ out_release:
 	return ret;
 }
 
-EXPORT_SYMBOL(do_splice_direct);
-
 /*
  * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same
  * location, so checking ->i_pipe is not enough to verify that this is a