f2fs: validate before set/clear free nat bitmap

In flush_nat_entries, all dirty nats will be flushed and if
their new address isn't NULL_ADDR, their bitmaps will be updated,
the free_nid_count of the bitmaps will be increaced regardless
of whether the nats have already been occupied before.
This could lead to wrong free_nid_count.
So this patch checks the status of the bits beforeactually
set/clear them.

Fixes: 586d1492f3 ("f2fs: skip scanning free nid bitmap of full NAT blocks")
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
LiFan 2017-11-10 15:41:42 +08:00 committed by Jaegeuk Kim
parent 19526d74cf
commit 0dd99ca76f

View File

@ -1906,15 +1906,18 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
return;
if (set)
if (set) {
if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
return;
__set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
else
__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
if (set)
nm_i->free_nid_count[nat_ofs]++;
else if (!build)
nm_i->free_nid_count[nat_ofs]--;
} else {
if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
return;
__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
if (!build)
nm_i->free_nid_count[nat_ofs]--;
}
}
static void scan_nat_page(struct f2fs_sb_info *sbi,