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SubjectRe: [PATCH] f2fs: avoid GC causing encrypted file corrupted
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On 2018/9/18 20:39, Yunlong Song wrote:
> The encrypted file may be corrupted by GC in following case:
>
> Time 1: | segment 1 blkaddr = A | GC -> | segment 2 blkaddr = B |
> Encrypted block 1 is moved from blkaddr A of segment 1 to blkaddr B of
> segment 2,
>
> Time 2: | segment 1 blkaddr = B | GC -> | segment 3 blkaddr = C |
>
> Before page 1 is written back and if segment 2 become a victim, then
> page 1 is moved from blkaddr B of segment 2 to blkaddr Cof segment 3,
> during the GC process of Time 2, f2fs should wait for page 1 written back
> before reading it, or move_data_block will read a garbage block from
> blkaddr B since page is not written back to blkaddr B yet.
>
> Commit 6aa58d8a ("f2fs: readahead encrypted block during GC") introduce
> ra_data_block to read encrypted block, but it forgets to add
> f2fs_wait_on_page_writeback to avoid racing between GC and flush.
>
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

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