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SubjectRe: [f2fs-dev] [PATCH RESEND v2] f2fs: validate before set/clear free nat bitmap
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On 2017/11/14 15:20, LiFan wrote:
> 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 increased 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 before actually set/clear them.
>
> Fixes: 586d1492f301 ("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>

Thanks,

> ---
> fs/f2fs/node.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index d234c6e..b965a53 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -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,
> --
> 2.7.4
>
>
>
>

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