Messages in this thread Patch in this message | | | Date | Wed, 10 Oct 2018 19:15:06 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] f2fs: fix data corruption issue with hardware encryption |
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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?
From 216037253e6c21530ced716940fa01978d801f0d 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 | 7 +++++++ 3 files changed, 20 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..2a75eb961982 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3301,6 +3301,13 @@ 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) +{ + for (; blkaddr < blkaddr + len; blkaddr++) + f2fs_wait_on_block_writeback(inode, blkaddr); +} + static int read_compacted_summaries(struct f2fs_sb_info *sbi) { struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); -- 2.19.0.605.g01d371f741-goog
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