Messages in this thread | | | Date | Thu, 11 Oct 2018 09:15:09 +0530 | From | Sahitya Tummala <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: fix data corruption issue with hardware encryption |
| |
On Wed, Oct 10, 2018 at 08:05:44PM -0700, Jaegeuk Kim wrote: > On 10/10, Jaegeuk Kim wrote: > > On 10/11, Sahitya Tummala wrote: > > > 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 <stummala@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); > > > > > > > Got it. > > How about this? > > > > Sorry, this is v2.
Looks good to me. Thanks for updating it :)
> > From b78dd7b2e0317be18716b9496269e9792829f63e Mon Sep 17 00:00:00 2001 > From: Sahitya Tummala <stummala@codeaurora.org> > Date: Wed, 10 Oct 2018 10:56:22 +0530 > Subject: [PATCH] f2fs: fix data corruption issue with hardware encryption > > 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 <stummala@codeaurora.org> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > --- > fs/f2fs/data.c | 11 +++++++++++ > fs/f2fs/f2fs.h | 2 ++ > fs/f2fs/segment.c | 9 +++++++++ > 3 files changed, 22 insertions(+) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index be19257d9e36..8952f2d610a6 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1030,6 +1030,11 @@ 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; > } > > @@ -1188,6 +1193,12 @@ 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 > index 7693b1a2072e..4a608a71c360 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -2986,6 +2986,8 @@ 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 > index 805c8310d7b0..f306d8946d99 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3301,6 +3301,15 @@ 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); > -- > 2.19.0.605.g01d371f741-goog >
-- -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
| |