[PATCH v2] f2fs: fix to truncate meta inode pages forcely

[Chao Yu <chao@kernel.org>]

Below race case can cause data corruption:

Thread A				GC thread
					- gc_data_segment
					 - ra_data_block
					  - locked meta_inode page
- f2fs_inplace_write_data
 - invalidate_mapping_pages
 : fail to invalidate meta_inode page
   due to lock failure or dirty|writeback
   status
 - f2fs_submit_page_bio
 : write last dirty data to old blkaddr
					 - move_data_block
					  - load old data from meta_inode page
					  - f2fs_submit_page_write
					  : write old data to new blkaddr

Because invalidate_mapping_pages() will skip invalidating page which
has unclear status including locked, dirty, writeback and so on, so
we need to use truncate_inode_pages_range() instead of
invalidate_mapping_pages() to make sure meta_inode page will be dropped.

Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC")
Fixes: e3b49ea36802 ("f2fs: invalidate META_MAPPING before IPU/DIO write")
Signed-off-by: Chao Yu <chao@kernel.org>
---
v2:
- fix race condition description.
 fs/f2fs/checkpoint.c    |  5 +++--
 fs/f2fs/f2fs.h          | 28 +++++++++++++++++++++++++++-
 fs/f2fs/segment.c       |  5 ++---
 include/linux/f2fs_fs.h |  1 +
 4 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index a09a9609e228..55b7d2cf030f 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1598,8 +1598,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	 */
 	if (f2fs_sb_has_encrypt(sbi) || f2fs_sb_has_verity(sbi) ||
 		f2fs_sb_has_compression(sbi))
-		invalidate_mapping_pages(META_MAPPING(sbi),
-				MAIN_BLKADDR(sbi), MAX_BLKADDR(sbi) - 1);
+		f2fs_bug_on(sbi,
+			invalidate_inode_pages2_range(META_MAPPING(sbi),
+				MAIN_BLKADDR(sbi), MAX_BLKADDR(sbi) - 1));
 
 	f2fs_release_ino_entry(sbi, false);
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4836e7cb0efe..9814e5981a6a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4655,10 +4655,36 @@ static inline bool f2fs_is_readonly(struct f2fs_sb_info *sbi)
 	return f2fs_sb_has_readonly(sbi) || f2fs_readonly(sbi->sb);
 }
 
+static inline void f2fs_truncate_meta_inode_pages(struct f2fs_sb_info *sbi,
+					block_t blkaddr, unsigned int cnt)
+{
+	bool need_submit = false;
+	int i = 0;
+
+	do {
+		struct page *page;
+
+		page = find_get_page(META_MAPPING(sbi), blkaddr + i);
+		if (page) {
+			if (PageWriteback(page))
+				need_submit = true;
+			f2fs_put_page(page, 0);
+		}
+	} while (++i < cnt && !need_submit);
+
+	if (need_submit)
+		f2fs_submit_merged_write_cond(sbi, sbi->meta_inode,
+							NULL, 0, DATA);
+
+	truncate_inode_pages_range(META_MAPPING(sbi),
+			F2FS_BLK_TO_BYTES((loff_t)blkaddr),
+			F2FS_BLK_END_BYTES((loff_t)(blkaddr + cnt - 1)));
+}
+
 static inline void f2fs_invalidate_internal_cache(struct f2fs_sb_info *sbi,
 								block_t blkaddr)
 {
-	invalidate_mapping_pages(META_MAPPING(sbi), blkaddr, blkaddr);
+	f2fs_truncate_meta_inode_pages(sbi, blkaddr, 1);
 	f2fs_invalidate_compress_page(sbi, blkaddr);
 }
 
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 4ff3b2d14ddf..20af48d7f784 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3741,8 +3741,7 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio)
 	}
 
 	if (fio->post_read)
-		invalidate_mapping_pages(META_MAPPING(sbi),
-				fio->new_blkaddr, fio->new_blkaddr);
+		f2fs_truncate_meta_inode_pages(sbi, fio->new_blkaddr, 1);
 
 	stat_inc_inplace_blocks(fio->sbi);
 
@@ -3932,7 +3931,7 @@ void f2fs_wait_on_block_writeback_range(struct inode *inode, block_t blkaddr,
 	for (i = 0; i < len; i++)
 		f2fs_wait_on_block_writeback(inode, blkaddr + i);
 
-	invalidate_mapping_pages(META_MAPPING(sbi), blkaddr, blkaddr + len - 1);
+	f2fs_truncate_meta_inode_pages(sbi, blkaddr, len);
 }
 
 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 755e9a41b196..a357287eac1e 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -27,6 +27,7 @@
 
 #define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
 #define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)
+#define F2FS_BLK_END_BYTES(blk)		(F2FS_BLK_TO_BYTES(blk + 1) - 1)
 
 /* 0, 1(node nid), 2(meta nid) are reserved node id */
 #define F2FS_RESERVED_NODE_NUM		3
-- 
2.40.1