From e2b4e2bc8865e03eecd49caa9713a2402a96bba9 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 19 Aug 2015 19:11:19 +0800 Subject: f2fs: fix incorrect mapping for bmap The test step is like below: 1. touch file 2. truncate -s $((1024*1024)) file 3. fallocate -o 0 -l $((1024*1024)) file 4. fibmap.f2fs file Our result of fibmap.f2fs showed below is not correct: file_pos start_blk end_blk blks 0 -937166132 -937166132 1 4096 -937166132 -937166132 1 8192 -937166132 -937166132 1 12288 -937166132 -937166132 1 16384 -937166132 -937166132 1 20480 -937166132 -937166132 1 ... 1040384 -937166132 -937166132 1 1044480 -937166132 -937166132 1 This is because f2fs_map_blocks will return with no error when meeting a hole or preallocated block, the caller __get_data_block will map the uninitialized variable value to bh->b_blocknr. Unfortunately generic_block_bmap will neither check the return value of get_data() nor check mapping info of buffer_head, result in returning the random block address. After fixing the issue, our result shows correctly: file_pos start_blk end_blk blks 0 0 0 256 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/f2fs/f2fs.h') diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 00591f725744..51dfa8fcc505 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -375,6 +375,12 @@ struct f2fs_map_blocks { unsigned int m_flags; }; +/* for flag in get_data_block */ +#define F2FS_GET_BLOCK_READ 0 +#define F2FS_GET_BLOCK_DIO 1 +#define F2FS_GET_BLOCK_FIEMAP 2 +#define F2FS_GET_BLOCK_BMAP 3 + /* * i_advise uses FADVISE_XXX_BIT. We can add additional hints later. */ -- cgit v1.2.1