2018-10-10 05:27:24

by Sahitya Tummala

[permalink] [raw]
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 <[email protected]>
---
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);
+ }
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.



2018-10-10 21:34:53

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix data corruption issue with hardware encryption

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 <[email protected]>
> ---
> 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.

> + }
> 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.

2018-10-11 00:30:26

by Sahitya Tummala

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix data corruption issue with hardware encryption

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 <[email protected]>
> > ---
> > 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.

2018-10-11 02:17:09

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix data corruption issue with hardware encryption

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 <[email protected]>
> > > ---
> > > 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 <[email protected]>
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 <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
---
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


2018-10-11 03:08:31

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH] f2fs: fix data corruption issue with hardware encryption

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 <[email protected]>
> > > > ---
> > > > 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.

From b78dd7b2e0317be18716b9496269e9792829f63e Mon Sep 17 00:00:00 2001
From: Sahitya Tummala <[email protected]>
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 <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
---
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


2018-10-11 03:46:24

by Sahitya Tummala

[permalink] [raw]
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 <[email protected]>
> > > > > ---
> > > > > 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 <[email protected]>
> 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 <[email protected]>
> Signed-off-by: Jaegeuk Kim <[email protected]>
> ---
> 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.

2018-10-15 12:27:50

by Chao Yu

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH] f2fs: fix data corruption issue with hardware encryption

On 2018/10/11 11:05, 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 <[email protected]>
>>>>> ---
>>>>> 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.
>
>>From b78dd7b2e0317be18716b9496269e9792829f63e Mon Sep 17 00:00:00 2001
> From: Sahitya Tummala <[email protected]>
> 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 <[email protected]>
> Signed-off-by: Jaegeuk Kim <[email protected]>

Nice catch!

Reviewed-by: Chao Yu <[email protected]>

Thanks,