4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 9bf1a3f73927492c8be127b642197125e9d52be8 ]
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 Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/gc.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index a07241fb8537..c96e7c6354ef 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -658,6 +658,14 @@ got_it: fio.page = page; fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
+ /* + * don't cache encrypted data into meta inode until previous dirty + * data were writebacked to avoid racing between GC and flush. + */ + f2fs_wait_on_page_writeback(page, DATA, true); + + f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); + fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi), dn.data_blkaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS); @@ -745,6 +753,8 @@ static int move_data_block(struct inode *inode, block_t bidx, */ f2fs_wait_on_page_writeback(page, DATA, true);
+ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); + err = f2fs_get_node_info(fio.sbi, dn.nid, &ni); if (err) goto put_out;