2014-02-07 08:12:46

by Chao Yu

[permalink] [raw]
Subject: [f2fs-dev] [PATCH V2] f2fs: introduce ra_meta_pages to readahead CP/NAT/SIT pages

This patch help us to cleanup the readahead code by merging ra_{sit,nat}_pages
function into ra_meta_pages.
Additionally the new function is used to readahead cp block in
recover_orphan_inodes.

Change log from v1:
o fix a deadloop bug pointed by Jaegeuk Kim.

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/checkpoint.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/f2fs/f2fs.h | 10 +++++++
fs/f2fs/node.c | 38 +-----------------------
fs/f2fs/segment.c | 43 +---------------------------
4 files changed, 90 insertions(+), 79 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8f5dff1..5f7f905 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -75,6 +75,82 @@ out:
return page;
}

+inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
+{
+ switch (type) {
+ case META_NAT:
+ return NM_I(sbi)->max_nid / NAT_ENTRY_PER_BLOCK;
+ case META_SIT:
+ return SIT_BLK_CNT(sbi);
+ case META_CP:
+ return 0;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Readahead CP/NAT/SIT pages
+ */
+int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
+{
+ block_t prev_blk_addr = 0;
+ struct page *page;
+ int blkno = start;
+ int max_blks = get_max_meta_blks(sbi, type);
+
+ struct f2fs_io_info fio = {
+ .type = META,
+ .rw = READ_SYNC | REQ_META | REQ_PRIO
+ };
+
+ for (; nrpages-- > 0; blkno++) {
+ block_t blk_addr;
+
+ switch (type) {
+ case META_NAT:
+ /* get nat block addr */
+ if (unlikely(blkno >= max_blks))
+ blkno = 0;
+ blk_addr = current_nat_addr(sbi,
+ blkno * NAT_ENTRY_PER_BLOCK);
+ break;
+ case META_SIT:
+ /* get sit block addr */
+ if (unlikely(blkno >= max_blks))
+ goto out;
+ blk_addr = current_sit_addr(sbi,
+ blkno * SIT_ENTRY_PER_BLOCK);
+ if (blkno != start && prev_blk_addr + 1 != blk_addr)
+ goto out;
+ prev_blk_addr = blk_addr;
+ break;
+ case META_CP:
+ /* get cp block addr */
+ blk_addr = blkno;
+ break;
+ default:
+ BUG();
+ }
+
+ page = grab_cache_page(META_MAPPING(sbi), blk_addr);
+ if (!page)
+ continue;
+ if (PageUptodate(page)) {
+ mark_page_accessed(page);
+ f2fs_put_page(page, 1);
+ continue;
+ }
+
+ f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
+ mark_page_accessed(page);
+ f2fs_put_page(page, 0);
+ }
+out:
+ f2fs_submit_merged_bio(sbi, META, READ);
+ return blkno - start;
+}
+
static int f2fs_write_meta_page(struct page *page,
struct writeback_control *wbc)
{
@@ -298,6 +374,8 @@ void recover_orphan_inodes(struct f2fs_sb_info *sbi)
start_blk = __start_cp_addr(sbi) + 1;
orphan_blkaddr = __start_sum_addr(sbi) - 1;

+ ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
+
for (i = 0; i < orphan_blkaddr; i++) {
struct page *page = get_meta_page(sbi, start_blk + i);
struct f2fs_orphan_block *orphan_blk;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index aeff132..15109f5 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -88,6 +88,15 @@ enum {
SIT_BITMAP
};

+/*
+ * For CP/NAT/SIT readahead
+ */
+enum {
+ META_CP,
+ META_NAT,
+ META_SIT
+};
+
/* for the list of orphan inodes */
struct orphan_inode_entry {
struct list_head list; /* list head */
@@ -1171,6 +1180,7 @@ void destroy_segment_manager_caches(void);
*/
struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
+int ra_meta_pages(struct f2fs_sb_info *, int, int, int);
long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
int acquire_orphan_inode(struct f2fs_sb_info *);
void release_orphan_inode(struct f2fs_sb_info *);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 82f4753..7689f91 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -82,42 +82,6 @@ static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
return dst_page;
}

-/*
- * Readahead NAT pages
- */
-static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
-{
- struct address_space *mapping = META_MAPPING(sbi);
- struct f2fs_nm_info *nm_i = NM_I(sbi);
- struct page *page;
- pgoff_t index;
- int i;
- struct f2fs_io_info fio = {
- .type = META,
- .rw = READ_SYNC | REQ_META | REQ_PRIO
- };
-
-
- for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
- if (unlikely(nid >= nm_i->max_nid))
- nid = 0;
- index = current_nat_addr(sbi, nid);
-
- page = grab_cache_page(mapping, index);
- if (!page)
- continue;
- if (PageUptodate(page)) {
- mark_page_accessed(page);
- f2fs_put_page(page, 1);
- continue;
- }
- f2fs_submit_page_mbio(sbi, page, index, &fio);
- mark_page_accessed(page);
- f2fs_put_page(page, 0);
- }
- f2fs_submit_merged_bio(sbi, META, READ);
-}
-
static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
{
return radix_tree_lookup(&nm_i->nat_root, n);
@@ -1413,7 +1377,7 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
return;

/* readahead nat pages to be scanned */
- ra_nat_pages(sbi, nid);
+ ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);

while (1) {
struct page *page = get_current_nat_page(sbi, nid);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e87946a..fbb41ba 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1576,47 +1576,6 @@ static int build_curseg(struct f2fs_sb_info *sbi)
return restore_curseg_summaries(sbi);
}

-static int ra_sit_pages(struct f2fs_sb_info *sbi, int start, int nrpages)
-{
- struct address_space *mapping = META_MAPPING(sbi);
- struct page *page;
- block_t blk_addr, prev_blk_addr = 0;
- int sit_blk_cnt = SIT_BLK_CNT(sbi);
- int blkno = start;
- struct f2fs_io_info fio = {
- .type = META,
- .rw = READ_SYNC | REQ_META | REQ_PRIO
- };
-
- for (; blkno < start + nrpages && blkno < sit_blk_cnt; blkno++) {
-
- blk_addr = current_sit_addr(sbi, blkno * SIT_ENTRY_PER_BLOCK);
-
- if (blkno != start && prev_blk_addr + 1 != blk_addr)
- break;
- prev_blk_addr = blk_addr;
-repeat:
- page = grab_cache_page(mapping, blk_addr);
- if (!page) {
- cond_resched();
- goto repeat;
- }
- if (PageUptodate(page)) {
- mark_page_accessed(page);
- f2fs_put_page(page, 1);
- continue;
- }
-
- f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
-
- mark_page_accessed(page);
- f2fs_put_page(page, 0);
- }
-
- f2fs_submit_merged_bio(sbi, META, READ);
- return blkno - start;
-}
-
static void build_sit_entries(struct f2fs_sb_info *sbi)
{
struct sit_info *sit_i = SIT_I(sbi);
@@ -1628,7 +1587,7 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));

do {
- readed = ra_sit_pages(sbi, start_blk, nrpages);
+ readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);

start = start_blk * sit_i->sents_per_block;
end = (start_blk + readed) * sit_i->sents_per_block;
--
1.7.9.5