On Wed, Oct 10, 2018 at 02:34:02PM -0700, Jaegeuk Kim wrote: > On 10/10, Sahitya Tummala wrote: > > 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- > > -> write file#1 in direct IO > > -> GC gets kicked in > > -> GC submitted bio on meta mapping > > for file#1, but pending completion > > -> write file#1 again with new data > > in direct IO > > -> GC bio gets completed now > > -> 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 <stumm...@codeaurora.org> > > --- > > fs/f2fs/data.c | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index 9ef6f1f..7b2fef0 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1028,6 +1028,12 @@ int f2fs_map_blocks(struct inode *inode, struct > > f2fs_map_blocks *map, > > map->m_pblk = ei.blk + pgofs - ei.fofs; > > map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs); > > map->m_flags = F2FS_MAP_MAPPED; > > + /* for HW encryption, but to avoid potential issue in future */ > > + if (flag == F2FS_GET_BLOCK_DIO) { > > + blkaddr = map->m_pblk; > > + for (; blkaddr < map->m_pblk + map->m_len; blkaddr++) > > + f2fs_wait_on_block_writeback(sbi, blkaddr); > > Do we need this? IIRC, DIO would give create=1.
Yes, we need it. When we are overwriting an existing file, DIO calls f2fs_map_blocks() with create=0. From the DIO code, I see that this happens because blockdev_direct_IO() passes this dio flag DIO_SKIP_HOLES. And then in get_more_blocks(), below code updates create=0, when we are overwriting an existing file. create = dio->op == REQ_OP_WRITE; if (dio->flags & DIO_SKIP_HOLES) { if (fs_startblk <= ((i_size_read(dio->inode) - 1) >> i_blkbits)) create = 0; } ret = (*sdio->get_block)(dio->inode, fs_startblk, map_bh, create); > > > + } > > if (map->m_next_extent) > > *map->m_next_extent = pgofs + map->m_len; > > goto out; > > @@ -1188,6 +1194,12 @@ 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) { > > + blkaddr = map->m_pblk; > > + for (; blkaddr < map->m_pblk + map->m_len; blkaddr++) > > + f2fs_wait_on_block_writeback(sbi, blkaddr); > > + } > > if (flag == F2FS_GET_BLOCK_PRECACHE) { > > if (map->m_flags & F2FS_MAP_MAPPED) { > > unsigned int ofs = start_pgofs - map->m_lblk; > > -- > > Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, > > Inc. > > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux > > Foundation Collaborative Project. -- -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel