[PATCH 2/3] f2fs: fix get stale meta pages when build free nids

From: Wanpeng Li
Date: Sun Mar 08 2015 - 23:19:43 EST


The blocks of nat pages to be scanned will be readahead when build free
nids. The start blkno will be adjusted to 0 when the intended range over
max_nids, then function ra_meta_pages readahead the right blkno, however,
function get_current_nat_page which is called in build_free_nids still
get the meta pages w/ stale blkno, this patch fix it by adjusting the nid
and the blkno which will be readahead in avdance in order to readahead and
get the right meta pages.

Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 3 ---
fs/f2fs/node.c | 9 ++++++++-
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 53bc328..aedb441 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -129,9 +129,6 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages, int type

switch (type) {
case META_NAT:
- if (unlikely(blkno >=
- NAT_BLOCK_OFFSET(NM_I(sbi)->max_nid)))
- blkno = 0;
/* get nat block addr */
fio.blk_addr = current_nat_addr(sbi,
blkno * NAT_ENTRY_PER_BLOCK);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 1a7e925..8751375 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1509,13 +1509,20 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
struct f2fs_summary_block *sum = curseg->sum_blk;
int i = 0;
nid_t nid = nm_i->next_scan_nid;
+ block_t blkno = NAT_BLOCK_OFFSET(nid);

/* Enough entries */
if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
return;

+ if (unlikely(blkno >=
+ NAT_BLOCK_OFFSET(NM_I(sbi)->max_nid))) {
+ blkno = 0;
+ nid = 0;
+ }
+
/* readahead nat pages to be scanned */
- ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
+ ra_meta_pages(sbi, blkno, FREE_NID_PAGES, META_NAT);

while (1) {
struct page *page = get_current_nat_page(sbi, nid);
--
1.9.1

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