* [f2fs-dev] [PATCH] f2fs: validate before set/clear free nat bitmap
@ 2017-11-10 7:41 ` LiFan
0 siblings, 0 replies; 3+ messages in thread
From: LiFan @ 2017-11-10 7:41 UTC (permalink / raw)
To: 'Chao Yu', 'Chao Yu', 'Jaegeuk Kim'
Cc: linux-kernel, linux-f2fs-devel
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.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [f2fs-dev] [PATCH] f2fs: validate before set/clear free nat bitmap
2017-11-10 7:41 ` LiFan
(?)
@ 2017-11-11 0:51 ` Chao Yu
-1 siblings, 0 replies; 3+ messages in thread
From: Chao Yu @ 2017-11-11 0:51 UTC (permalink / raw)
To: LiFan, 'Chao Yu', 'Jaegeuk Kim'
Cc: linux-kernel, linux-f2fs-devel, chao
On 2017/11/10 15:41, 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 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.
Thanks for fixing this. :)
Please add:
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,
>
^ permalink raw reply [flat|nested] 3+ messages in thread