f2fs: fix data corruption issue with hardware encryption

Sahitya Tummala · Jaegeuk Kim · commit 1e78e8bd9d10 · 2018-10-22T17:54:47.000-07:00
Direct IO can be used in case of hardware encryption. The following
scenario results into data corruption issue in this path -

Thread A -                          Thread B-
-&gt; write file#1 in direct IO
                                    -&gt; GC gets kicked in
                                    -&gt; GC submitted bio on meta mapping
				       for file#1, but pending completion
-&gt; write file#1 again with new data
   in direct IO
                                    -&gt; GC bio gets completed now
                                    -&gt; GC writes old data to the new
                                       location and thus file#1 is
				       corrupted.

Fix this by submitting and waiting for pending io on meta mapping
for direct IO case in f2fs_map_blocks().

Signed-off-by: Sahitya Tummala &lt;stummala@codeaurora.org&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
@@ -1053,6 +1053,11 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 		map->m_flags = F2FS_MAP_MAPPED;
 		if (map->m_next_extent)
 			*map->m_next_extent = pgofs + map->m_len;
+
+		/* for hardware encryption, but to avoid potential issue in future */
+		if (flag == F2FS_GET_BLOCK_DIO)
+			f2fs_wait_on_block_writeback_range(inode,
+						map->m_pblk, map->m_len);
 		goto out;
 	}
 
@@ -1211,6 +1216,12 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 	goto next_dnode;
 
 sync_out:
+
+	/* for hardware encryption, but to avoid potential issue in future */
+	if (flag == F2FS_GET_BLOCK_DIO && map->m_flags & F2FS_MAP_MAPPED)
+		f2fs_wait_on_block_writeback_range(inode,
+						map->m_pblk, map->m_len);
+
 	if (flag == F2FS_GET_BLOCK_PRECACHE) {
 		if (map->m_flags & F2FS_MAP_MAPPED) {
 			unsigned int ofs = start_pgofs - map->m_lblk;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
@@ -2988,6 +2988,8 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 void f2fs_wait_on_page_writeback(struct page *page,
 			enum page_type type, bool ordered);
 void f2fs_wait_on_block_writeback(struct inode *inode, block_t blkaddr);
+void f2fs_wait_on_block_writeback_range(struct inode *inode, block_t blkaddr,
+								block_t len);
 void f2fs_write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk);
 void f2fs_write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk);
 int f2fs_lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
@@ -3303,6 +3303,15 @@ void f2fs_wait_on_block_writeback(struct inode *inode, block_t blkaddr)
 	}
 }
 
+void f2fs_wait_on_block_writeback_range(struct inode *inode, block_t blkaddr,
+								block_t len)
+{
+	block_t i;
+
+	for (i = 0; i < len; i++)
+		f2fs_wait_on_block_writeback(inode, blkaddr + i);
+}
+
 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);

Original file line number	Diff line number	Diff line change
`@@ -3303,6 +3303,15 @@ void f2fs_wait_on_block_writeback(struct inode *inode, block_t blkaddr)`
`3303`	`3303`	`}`
`3304`	`3304`	`}`
`3305`	`3305`
	`3306`	`+void f2fs_wait_on_block_writeback_range(struct inode *inode, block_t blkaddr,`
	`3307`	`+ block_t len)`
	`3308`	`+{`
	`3309`	`+ block_t i;`
	`3310`	`+`
	`3311`	`+ for (i = 0; i < len; i++)`
	`3312`	`+ f2fs_wait_on_block_writeback(inode, blkaddr + i);`
	`3313`	`+}`
	`3314`	`+`
`3306`	`3315`	`static int read_compacted_summaries(struct f2fs_sb_info *sbi)`
`3307`	`3316`	`{`
`3308`	`3317`	`struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);`