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* [f2fs-dev] [PATCH] f2fs: fix to add swap extent correctly
@ 2020-02-10  7:01 Chao Yu
  0 siblings, 0 replies; 4+ messages in thread
From: Chao Yu @ 2020-02-10  7:01 UTC (permalink / raw)
  To: jaegeuk; +Cc: linux-kernel, stable, linux-f2fs-devel

As Youling reported in mailing list:

https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/

https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/

There is a test case can corrupt f2fs image:
- dd if=/dev/zero of=/swapfile bs=1M count=4096
- chmod 600 /swapfile
- mkswap /swapfile
- swapon --discard /swapfile

The root cause is f2fs_swap_activate() intends to return zero value
to setup_swap_extents() to enable SWP_FS mode (swap file goes through
fs), in this flow, setup_swap_extents() setups swap extent with wrong
block address range, result in discard_swap() erasing incorrect address.

Because f2fs_swap_activate() has pinned swapfile, its data block
address will not change, it's safe to let swap to handle IO through
raw device, so we can get rid of SWAP_FS mode and initial swap extents
inside f2fs_swap_activate(), by this way, later discard_swap() can trim
in right address range.

Fixes: 4969c06a0d83 ("f2fs: support swap file w/ DIO")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/data.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 98c946dfee13..b56437d4973d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3627,7 +3627,8 @@ int f2fs_migrate_page(struct address_space *mapping,
 
 #ifdef CONFIG_SWAP
 /* Copied from generic_swapfile_activate() to check any holes */
-static int check_swap_activate(struct file *swap_file, unsigned int max)
+static int check_swap_activate(struct swap_info_struct *sis,
+				struct file *swap_file, sector_t *span)
 {
 	struct address_space *mapping = swap_file->f_mapping;
 	struct inode *inode = mapping->host;
@@ -3638,6 +3639,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 	sector_t last_block;
 	sector_t lowest_block = -1;
 	sector_t highest_block = 0;
+	int nr_extents = 0;
+	int ret;
 
 	blkbits = inode->i_blkbits;
 	blocks_per_page = PAGE_SIZE >> blkbits;
@@ -3649,7 +3652,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 	probe_block = 0;
 	page_no = 0;
 	last_block = i_size_read(inode) >> blkbits;
-	while ((probe_block + blocks_per_page) <= last_block && page_no < max) {
+	while ((probe_block + blocks_per_page) <= last_block &&
+			page_no < sis->max) {
 		unsigned block_in_page;
 		sector_t first_block;
 
@@ -3689,13 +3693,27 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 				highest_block = first_block;
 		}
 
+		/*
+		 * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
+		 */
+		ret = add_swap_extent(sis, page_no, 1, first_block);
+		if (ret < 0)
+			goto out;
+		nr_extents += ret;
 		page_no++;
 		probe_block += blocks_per_page;
 reprobe:
 		continue;
 	}
-	return 0;
-
+	ret = nr_extents;
+	*span = 1 + highest_block - lowest_block;
+	if (page_no == 0)
+		page_no = 1;	/* force Empty message */
+	sis->max = page_no;
+	sis->pages = page_no - 1;
+	sis->highest_bit = page_no - 1;
+out:
+	return ret;
 bad_bmap:
 	pr_err("swapon: swapfile has holes\n");
 	return -EINVAL;
@@ -3720,14 +3738,14 @@ static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
 	if (f2fs_disable_compressed_file(inode))
 		return -EINVAL;
 
-	ret = check_swap_activate(file, sis->max);
-	if (ret)
+	ret = check_swap_activate(sis, file, span);
+	if (ret < 0)
 		return ret;
 
 	set_inode_flag(inode, FI_PIN_FILE);
 	f2fs_precache_extents(inode);
 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
-	return 0;
+	return ret;
 }
 
 static void f2fs_swap_deactivate(struct file *file)
-- 
2.18.0.rc1



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: fix to add swap extent correctly
  2020-02-07  6:42 ` Ju Hyung Park
@ 2020-02-10  6:58   ` Chao Yu
  0 siblings, 0 replies; 4+ messages in thread
From: Chao Yu @ 2020-02-10  6:58 UTC (permalink / raw)
  To: Ju Hyung Park; +Cc: Jaegeuk Kim, linux-kernel, linux-f2fs-devel

Hi Ju Hyung,

On 2020/2/7 14:42, Ju Hyung Park wrote:
> Hi Chao,
> 
> I think this should be sent to linux-stable.
> Thoughts?

Yup, I forgot to Cc stable mailing list, let me resend it.

Thanks for reminding me that.

Thanks,

> 
> Thanks.
> 
> On Fri, Dec 27, 2019 at 7:45 PM Chao Yu <yuchao0@huawei.com> wrote:
>>
>> As Youling reported in mailing list:
>>
>> https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/
>>
>> https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/
>>
>> There is a test case can corrupt f2fs image:
>> - dd if=/dev/zero of=/swapfile bs=1M count=4096
>> - chmod 600 /swapfile
>> - mkswap /swapfile
>> - swapon --discard /swapfile
>>
>> The root cause is f2fs_swap_activate() intends to return zero value
>> to setup_swap_extents() to enable SWP_FS mode (swap file goes through
>> fs), in this flow, setup_swap_extents() setups swap extent with wrong
>> block address range, result in discard_swap() erasing incorrect address.
>>
>> Because f2fs_swap_activate() has pinned swapfile, its data block
>> address will not change, it's safe to let swap to handle IO through
>> raw device, so we can get rid of SWAP_FS mode and initial swap extents
>> inside f2fs_swap_activate(), by this way, later discard_swap() can trim
>> in right address range.
>>
>> Fixes: 4969c06a0d83 ("f2fs: support swap file w/ DIO")
>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>> ---
>>  fs/f2fs/data.c | 32 +++++++++++++++++++++++++-------
>>  1 file changed, 25 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index 19cd03450066..ee4d3d284379 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -3608,7 +3608,8 @@ int f2fs_migrate_page(struct address_space *mapping,
>>
>>  #ifdef CONFIG_SWAP
>>  /* Copied from generic_swapfile_activate() to check any holes */
>> -static int check_swap_activate(struct file *swap_file, unsigned int max)
>> +static int check_swap_activate(struct swap_info_struct *sis,
>> +                               struct file *swap_file, sector_t *span)
>>  {
>>         struct address_space *mapping = swap_file->f_mapping;
>>         struct inode *inode = mapping->host;
>> @@ -3619,6 +3620,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>>         sector_t last_block;
>>         sector_t lowest_block = -1;
>>         sector_t highest_block = 0;
>> +       int nr_extents = 0;
>> +       int ret;
>>
>>         blkbits = inode->i_blkbits;
>>         blocks_per_page = PAGE_SIZE >> blkbits;
>> @@ -3630,7 +3633,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>>         probe_block = 0;
>>         page_no = 0;
>>         last_block = i_size_read(inode) >> blkbits;
>> -       while ((probe_block + blocks_per_page) <= last_block && page_no < max) {
>> +       while ((probe_block + blocks_per_page) <= last_block &&
>> +                       page_no < sis->max) {
>>                 unsigned block_in_page;
>>                 sector_t first_block;
>>
>> @@ -3670,13 +3674,27 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>>                                 highest_block = first_block;
>>                 }
>>
>> +               /*
>> +                * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
>> +                */
>> +               ret = add_swap_extent(sis, page_no, 1, first_block);
>> +               if (ret < 0)
>> +                       goto out;
>> +               nr_extents += ret;
>>                 page_no++;
>>                 probe_block += blocks_per_page;
>>  reprobe:
>>                 continue;
>>         }
>> -       return 0;
>> -
>> +       ret = nr_extents;
>> +       *span = 1 + highest_block - lowest_block;
>> +       if (page_no == 0)
>> +               page_no = 1;    /* force Empty message */
>> +       sis->max = page_no;
>> +       sis->pages = page_no - 1;
>> +       sis->highest_bit = page_no - 1;
>> +out:
>> +       return ret;
>>  bad_bmap:
>>         pr_err("swapon: swapfile has holes\n");
>>         return -EINVAL;
>> @@ -3701,14 +3719,14 @@ static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
>>         if (f2fs_disable_compressed_file(inode))
>>                 return -EINVAL;
>>
>> -       ret = check_swap_activate(file, sis->max);
>> -       if (ret)
>> +       ret = check_swap_activate(sis, file, span);
>> +       if (ret < 0)
>>                 return ret;
>>
>>         set_inode_flag(inode, FI_PIN_FILE);
>>         f2fs_precache_extents(inode);
>>         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
>> -       return 0;
>> +       return ret;
>>  }
>>
>>  static void f2fs_swap_deactivate(struct file *file)
>> --
>> 2.18.0.rc1
>>
>>
>>
>> _______________________________________________
>> Linux-f2fs-devel mailing list
>> Linux-f2fs-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> .
> 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: fix to add swap extent correctly
  2019-12-27 10:44 Chao Yu
@ 2020-02-07  6:42 ` Ju Hyung Park
  2020-02-10  6:58   ` Chao Yu
  0 siblings, 1 reply; 4+ messages in thread
From: Ju Hyung Park @ 2020-02-07  6:42 UTC (permalink / raw)
  To: Chao Yu; +Cc: Jaegeuk Kim, linux-kernel, linux-f2fs-devel

Hi Chao,

I think this should be sent to linux-stable.
Thoughts?

Thanks.

On Fri, Dec 27, 2019 at 7:45 PM Chao Yu <yuchao0@huawei.com> wrote:
>
> As Youling reported in mailing list:
>
> https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/
>
> https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/
>
> There is a test case can corrupt f2fs image:
> - dd if=/dev/zero of=/swapfile bs=1M count=4096
> - chmod 600 /swapfile
> - mkswap /swapfile
> - swapon --discard /swapfile
>
> The root cause is f2fs_swap_activate() intends to return zero value
> to setup_swap_extents() to enable SWP_FS mode (swap file goes through
> fs), in this flow, setup_swap_extents() setups swap extent with wrong
> block address range, result in discard_swap() erasing incorrect address.
>
> Because f2fs_swap_activate() has pinned swapfile, its data block
> address will not change, it's safe to let swap to handle IO through
> raw device, so we can get rid of SWAP_FS mode and initial swap extents
> inside f2fs_swap_activate(), by this way, later discard_swap() can trim
> in right address range.
>
> Fixes: 4969c06a0d83 ("f2fs: support swap file w/ DIO")
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/data.c | 32 +++++++++++++++++++++++++-------
>  1 file changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 19cd03450066..ee4d3d284379 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -3608,7 +3608,8 @@ int f2fs_migrate_page(struct address_space *mapping,
>
>  #ifdef CONFIG_SWAP
>  /* Copied from generic_swapfile_activate() to check any holes */
> -static int check_swap_activate(struct file *swap_file, unsigned int max)
> +static int check_swap_activate(struct swap_info_struct *sis,
> +                               struct file *swap_file, sector_t *span)
>  {
>         struct address_space *mapping = swap_file->f_mapping;
>         struct inode *inode = mapping->host;
> @@ -3619,6 +3620,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>         sector_t last_block;
>         sector_t lowest_block = -1;
>         sector_t highest_block = 0;
> +       int nr_extents = 0;
> +       int ret;
>
>         blkbits = inode->i_blkbits;
>         blocks_per_page = PAGE_SIZE >> blkbits;
> @@ -3630,7 +3633,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>         probe_block = 0;
>         page_no = 0;
>         last_block = i_size_read(inode) >> blkbits;
> -       while ((probe_block + blocks_per_page) <= last_block && page_no < max) {
> +       while ((probe_block + blocks_per_page) <= last_block &&
> +                       page_no < sis->max) {
>                 unsigned block_in_page;
>                 sector_t first_block;
>
> @@ -3670,13 +3674,27 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
>                                 highest_block = first_block;
>                 }
>
> +               /*
> +                * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
> +                */
> +               ret = add_swap_extent(sis, page_no, 1, first_block);
> +               if (ret < 0)
> +                       goto out;
> +               nr_extents += ret;
>                 page_no++;
>                 probe_block += blocks_per_page;
>  reprobe:
>                 continue;
>         }
> -       return 0;
> -
> +       ret = nr_extents;
> +       *span = 1 + highest_block - lowest_block;
> +       if (page_no == 0)
> +               page_no = 1;    /* force Empty message */
> +       sis->max = page_no;
> +       sis->pages = page_no - 1;
> +       sis->highest_bit = page_no - 1;
> +out:
> +       return ret;
>  bad_bmap:
>         pr_err("swapon: swapfile has holes\n");
>         return -EINVAL;
> @@ -3701,14 +3719,14 @@ static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
>         if (f2fs_disable_compressed_file(inode))
>                 return -EINVAL;
>
> -       ret = check_swap_activate(file, sis->max);
> -       if (ret)
> +       ret = check_swap_activate(sis, file, span);
> +       if (ret < 0)
>                 return ret;
>
>         set_inode_flag(inode, FI_PIN_FILE);
>         f2fs_precache_extents(inode);
>         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
> -       return 0;
> +       return ret;
>  }
>
>  static void f2fs_swap_deactivate(struct file *file)
> --
> 2.18.0.rc1
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [f2fs-dev] [PATCH] f2fs: fix to add swap extent correctly
@ 2019-12-27 10:44 Chao Yu
  2020-02-07  6:42 ` Ju Hyung Park
  0 siblings, 1 reply; 4+ messages in thread
From: Chao Yu @ 2019-12-27 10:44 UTC (permalink / raw)
  To: jaegeuk; +Cc: linux-kernel, linux-f2fs-devel

As Youling reported in mailing list:

https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/

https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/

There is a test case can corrupt f2fs image:
- dd if=/dev/zero of=/swapfile bs=1M count=4096
- chmod 600 /swapfile
- mkswap /swapfile
- swapon --discard /swapfile

The root cause is f2fs_swap_activate() intends to return zero value
to setup_swap_extents() to enable SWP_FS mode (swap file goes through
fs), in this flow, setup_swap_extents() setups swap extent with wrong
block address range, result in discard_swap() erasing incorrect address.

Because f2fs_swap_activate() has pinned swapfile, its data block
address will not change, it's safe to let swap to handle IO through
raw device, so we can get rid of SWAP_FS mode and initial swap extents
inside f2fs_swap_activate(), by this way, later discard_swap() can trim
in right address range.

Fixes: 4969c06a0d83 ("f2fs: support swap file w/ DIO")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/data.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 19cd03450066..ee4d3d284379 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3608,7 +3608,8 @@ int f2fs_migrate_page(struct address_space *mapping,
 
 #ifdef CONFIG_SWAP
 /* Copied from generic_swapfile_activate() to check any holes */
-static int check_swap_activate(struct file *swap_file, unsigned int max)
+static int check_swap_activate(struct swap_info_struct *sis,
+				struct file *swap_file, sector_t *span)
 {
 	struct address_space *mapping = swap_file->f_mapping;
 	struct inode *inode = mapping->host;
@@ -3619,6 +3620,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 	sector_t last_block;
 	sector_t lowest_block = -1;
 	sector_t highest_block = 0;
+	int nr_extents = 0;
+	int ret;
 
 	blkbits = inode->i_blkbits;
 	blocks_per_page = PAGE_SIZE >> blkbits;
@@ -3630,7 +3633,8 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 	probe_block = 0;
 	page_no = 0;
 	last_block = i_size_read(inode) >> blkbits;
-	while ((probe_block + blocks_per_page) <= last_block && page_no < max) {
+	while ((probe_block + blocks_per_page) <= last_block &&
+			page_no < sis->max) {
 		unsigned block_in_page;
 		sector_t first_block;
 
@@ -3670,13 +3674,27 @@ static int check_swap_activate(struct file *swap_file, unsigned int max)
 				highest_block = first_block;
 		}
 
+		/*
+		 * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
+		 */
+		ret = add_swap_extent(sis, page_no, 1, first_block);
+		if (ret < 0)
+			goto out;
+		nr_extents += ret;
 		page_no++;
 		probe_block += blocks_per_page;
 reprobe:
 		continue;
 	}
-	return 0;
-
+	ret = nr_extents;
+	*span = 1 + highest_block - lowest_block;
+	if (page_no == 0)
+		page_no = 1;	/* force Empty message */
+	sis->max = page_no;
+	sis->pages = page_no - 1;
+	sis->highest_bit = page_no - 1;
+out:
+	return ret;
 bad_bmap:
 	pr_err("swapon: swapfile has holes\n");
 	return -EINVAL;
@@ -3701,14 +3719,14 @@ static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
 	if (f2fs_disable_compressed_file(inode))
 		return -EINVAL;
 
-	ret = check_swap_activate(file, sis->max);
-	if (ret)
+	ret = check_swap_activate(sis, file, span);
+	if (ret < 0)
 		return ret;
 
 	set_inode_flag(inode, FI_PIN_FILE);
 	f2fs_precache_extents(inode);
 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
-	return 0;
+	return ret;
 }
 
 static void f2fs_swap_deactivate(struct file *file)
-- 
2.18.0.rc1



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread

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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-10  7:01 [f2fs-dev] [PATCH] f2fs: fix to add swap extent correctly Chao Yu
  -- strict thread matches above, loose matches on Subject: below --
2019-12-27 10:44 Chao Yu
2020-02-07  6:42 ` Ju Hyung Park
2020-02-10  6:58   ` Chao Yu

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