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Message-Id: <1430527726-68547-7-git-send-email-jaegeuk@kernel.org>
Date: Fri, 1 May 2015 17:48:34 -0700
From: Jaegeuk Kim <jaegeuk@...nel.org>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net
Cc: Jaegeuk Kim <jaegeuk@...nel.org>
Subject: [PATCH 07/19] f2fs: expose f2fs_mpage_readpages
This patch implements f2fs_mpage_readpages for further optimization on
encryption support.
The basic code was taken from fs/mpage.c, and changed to be simple by adjusting
that block_size is equal to page_size in f2fs.
Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
---
fs/f2fs/data.c | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 154 insertions(+), 3 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index aa3c079..2a3a9cd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -18,6 +18,7 @@
#include <linux/bio.h>
#include <linux/prefetch.h>
#include <linux/uio.h>
+#include <linux/cleancache.h>
#include "f2fs.h"
#include "node.h"
@@ -47,6 +48,30 @@ static void f2fs_read_end_io(struct bio *bio, int err)
bio_put(bio);
}
+/*
+ * I/O completion handler for multipage BIOs.
+ * copied from fs/mpage.c
+ */
+static void mpage_end_io(struct bio *bio, int err)
+{
+ struct bio_vec *bv;
+ int i;
+
+ bio_for_each_segment_all(bv, bio, i) {
+ struct page *page = bv->bv_page;
+
+ if (!err) {
+ SetPageUptodate(page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+ unlock_page(page);
+ }
+
+ bio_put(bio);
+}
+
static void f2fs_write_end_io(struct bio *bio, int err)
{
struct f2fs_sb_info *sbi = bio->bi_private;
@@ -1349,6 +1374,133 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
start, len, get_data_block_fiemap);
}
+/*
+ * This function was originally taken from fs/mpage.c, and customized for f2fs.
+ * Major change was from block_size == page_size in f2fs by default.
+ */
+static int f2fs_mpage_readpages(struct address_space *mapping,
+ struct list_head *pages, struct page *page,
+ unsigned nr_pages)
+{
+ struct bio *bio = NULL;
+ unsigned page_idx;
+ sector_t last_block_in_bio = 0;
+ struct inode *inode = mapping->host;
+ const unsigned blkbits = inode->i_blkbits;
+ const unsigned blocksize = 1 << blkbits;
+ sector_t block_in_file;
+ sector_t last_block;
+ sector_t last_block_in_file;
+ sector_t block_nr;
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ struct f2fs_map_blocks map;
+
+ map.m_pblk = 0;
+ map.m_lblk = 0;
+ map.m_len = 0;
+ map.m_flags = 0;
+
+ for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
+
+ prefetchw(&page->flags);
+ if (pages) {
+ page = list_entry(pages->prev, struct page, lru);
+ list_del(&page->lru);
+ if (add_to_page_cache_lru(page, mapping,
+ page->index, GFP_KERNEL))
+ goto next_page;
+ }
+
+ block_in_file = (sector_t)page->index;
+ last_block = block_in_file + nr_pages;
+ last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
+ blkbits;
+ if (last_block > last_block_in_file)
+ last_block = last_block_in_file;
+
+ /*
+ * Map blocks using the previous result first.
+ */
+ if ((map.m_flags & F2FS_MAP_MAPPED) &&
+ block_in_file > map.m_lblk &&
+ block_in_file < (map.m_lblk + map.m_len))
+ goto got_it;
+
+ /*
+ * Then do more f2fs_map_blocks() calls until we are
+ * done with this page.
+ */
+ map.m_flags = 0;
+
+ if (block_in_file < last_block) {
+ map.m_lblk = block_in_file;
+ map.m_len = last_block - block_in_file;
+
+ if (f2fs_map_blocks(inode, &map, 0, false))
+ goto set_error_page;
+ }
+got_it:
+ if ((map.m_flags & F2FS_MAP_MAPPED)) {
+ block_nr = map.m_pblk + block_in_file - map.m_lblk;
+ SetPageMappedToDisk(page);
+
+ if (!PageUptodate(page) && !cleancache_get_page(page)) {
+ SetPageUptodate(page);
+ goto confused;
+ }
+ } else {
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ unlock_page(page);
+ goto next_page;
+ }
+
+ /*
+ * This page will go to BIO. Do we need to send this
+ * BIO off first?
+ */
+ if (bio && (last_block_in_bio != block_nr - 1)) {
+submit_and_realloc:
+ submit_bio(READ, bio);
+ bio = NULL;
+ }
+ if (bio == NULL) {
+ bio = bio_alloc(GFP_KERNEL,
+ min_t(int, nr_pages, bio_get_nr_vecs(bdev)));
+ if (!bio)
+ goto set_error_page;
+ bio->bi_bdev = bdev;
+ bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
+ bio->bi_end_io = mpage_end_io;
+ bio->bi_private = NULL;
+ }
+
+ if (bio_add_page(bio, page, blocksize, 0) < blocksize)
+ goto submit_and_realloc;
+
+ last_block_in_bio = block_nr;
+ goto next_page;
+set_error_page:
+ SetPageError(page);
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ unlock_page(page);
+ goto next_page;
+confused:
+ if (bio) {
+ submit_bio(READ, bio);
+ bio = NULL;
+ }
+ unlock_page(page);
+next_page:
+ if (pages)
+ page_cache_release(page);
+ }
+ BUG_ON(pages && !list_empty(pages));
+ if (bio)
+ submit_bio(READ, bio);
+ return 0;
+}
+
static int f2fs_read_data_page(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
@@ -1360,8 +1512,7 @@ static int f2fs_read_data_page(struct file *file, struct page *page)
if (f2fs_has_inline_data(inode))
ret = f2fs_read_inline_data(inode, page);
if (ret == -EAGAIN)
- ret = mpage_readpage(page, get_data_block);
-
+ ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
return ret;
}
@@ -1375,7 +1526,7 @@ static int f2fs_read_data_pages(struct file *file,
if (f2fs_has_inline_data(inode))
return 0;
- return mpage_readpages(mapping, pages, nr_pages, get_data_block);
+ return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
}
int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
--
2.1.1
--
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