commit 9d5c4f5c7a upstream.
Assuming the disk layout as below,
disk0: 0 --- 0x00035abfff
disk1: 0x00035ac000 --- 0x00037abfff
disk2: 0x00037ac000 --- 0x00037ebfff
and we want to read data from offset=13568 having len=128 across the block
devices, we can illustrate the block addresses like below.
0 .. 0x00037ac000 ------------------- 0x00037ebfff, 0x00037ec000 -------
| ^ ^ ^
| fofs 0 13568 13568+128
| ------------------------------------------------------
| LBA 0x37e8aa9 0x37ebfa9 0x37ec029
--- map 0x3caa9 0x3ffa9
In this example, we should give the relative map of the target block device
ranging from 0x3caa9 to 0x3ffa9 where the length should be calculated by
0x37ebfff + 1 - 0x37ebfa9.
In the below equation, however, map->m_pblk was supposed to be the original
address instead of the one from the target block address.
- map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk);
Cc: stable@vger.kernel.org
Fixes: 71f2c82062 ("f2fs: multidevice: support direct IO")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
da52a3fc57