[PATCH 10/12] f2fs: Convert from readpages to readahead

[Matthew Wilcox <willy@infradead.org>]

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Use the new readahead operation in f2fs

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: linux-f2fs-devel@lists.sourceforge.net
---
 fs/f2fs/data.c              | 33 +++++++++++++--------------------
 include/trace/events/f2fs.h |  6 +++---
 2 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index a034cd0ce021..70bbcdfbd368 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1882,7 +1882,7 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
  * from read-ahead.
  */
 static int f2fs_mpage_readpages(struct address_space *mapping,
-			struct list_head *pages, struct page *page,
+			pgoff_t start, struct page *page,
 			unsigned nr_pages, bool is_readahead)
 {
 	struct bio *bio = NULL;
@@ -1901,15 +1901,10 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
 	map.m_may_create = false;
 
 	for (; nr_pages; nr_pages--) {
-		if (pages) {
-			page = list_last_entry(pages, struct page, lru);
+		if (is_readahead) {
+			page = readahead_page(mapping, start++);
 
 			prefetchw(&page->flags);
-			list_del(&page->lru);
-			if (add_to_page_cache_lru(page, mapping,
-						  page_index(page),
-						  readahead_gfp_mask(mapping)))
-				goto next_page;
 		}
 
 		ret = f2fs_read_single_page(inode, page, nr_pages, &map, &bio,
@@ -1919,14 +1914,12 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
 			zero_user_segment(page, 0, PAGE_SIZE);
 			unlock_page(page);
 		}
-next_page:
-		if (pages)
+		if (is_readahead)
 			put_page(page);
 	}
-	BUG_ON(pages && !list_empty(pages));
 	if (bio)
 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
-	return pages ? 0 : ret;
+	return ret;
 }
 
 static int f2fs_read_data_page(struct file *file, struct page *page)
@@ -1941,24 +1934,24 @@ static int f2fs_read_data_page(struct file *file, struct page *page)
 		ret = f2fs_read_inline_data(inode, page);
 	if (ret == -EAGAIN)
 		ret = f2fs_mpage_readpages(page_file_mapping(page),
-						NULL, page, 1, false);
+						0, page, 1, false);
 	return ret;
 }
 
-static int f2fs_read_data_pages(struct file *file,
+static unsigned f2fs_readahead(struct file *file,
 			struct address_space *mapping,
-			struct list_head *pages, unsigned nr_pages)
+			pgoff_t start, unsigned nr_pages)
 {
 	struct inode *inode = mapping->host;
-	struct page *page = list_last_entry(pages, struct page, lru);
 
-	trace_f2fs_readpages(inode, page, nr_pages);
+	trace_f2fs_readpages(inode, start, nr_pages);
 
 	/* If the file has inline data, skip readpages */
 	if (f2fs_has_inline_data(inode))
-		return 0;
+		return nr_pages;
 
-	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages, true);
+	f2fs_mpage_readpages(mapping, start, NULL, nr_pages, true);
+	return 0;
 }
 
 static int encrypt_one_page(struct f2fs_io_info *fio)
@@ -3265,7 +3258,7 @@ static void f2fs_swap_deactivate(struct file *file)
 
 const struct address_space_operations f2fs_dblock_aops = {
 	.readpage	= f2fs_read_data_page,
-	.readpages	= f2fs_read_data_pages,
+	.readahead	= f2fs_readahead,
 	.writepage	= f2fs_write_data_page,
 	.writepages	= f2fs_write_data_pages,
 	.write_begin	= f2fs_write_begin,
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 1796ff99c3e9..35b5bb2188a3 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -1368,9 +1368,9 @@ TRACE_EVENT(f2fs_writepages,
 
 TRACE_EVENT(f2fs_readpages,
 
-	TP_PROTO(struct inode *inode, struct page *page, unsigned int nrpage),
+	TP_PROTO(struct inode *inode, pgoff_t start, unsigned int nrpage),
 
-	TP_ARGS(inode, page, nrpage),
+	TP_ARGS(inode, start, nrpage),
 
 	TP_STRUCT__entry(
 		__field(dev_t,	dev)
@@ -1382,7 +1382,7 @@ TRACE_EVENT(f2fs_readpages,
 	TP_fast_assign(
 		__entry->dev	= inode->i_sb->s_dev;
 		__entry->ino	= inode->i_ino;
-		__entry->start	= page->index;
+		__entry->start	= start;
 		__entry->nrpage	= nrpage;
 	),
 
-- 
2.24.1