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* [PATCH 0/3] Preparatory to add the csum check in the scan context
@ 2018-03-20  9:53 Anand Jain
  2018-03-20  9:53 ` [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
                   ` (3 more replies)
  0 siblings, 4 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-20  9:53 UTC (permalink / raw)
  To: linux-btrfs

Anand Jain (3):
  btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the
    type
  btrfs: return required error from btrfs_check_super_csum
  btrfs: refactor btrfs_check_super_csum() for scan

 fs/btrfs/disk-io.c | 50 ++++++++++++++++++++++++--------------------------
 fs/btrfs/disk-io.h |  1 +
 2 files changed, 25 insertions(+), 26 deletions(-)

-- 
2.15.0


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type
  2018-03-20  9:53 [PATCH 0/3] Preparatory to add the csum check in the scan context Anand Jain
@ 2018-03-20  9:53 ` Anand Jain
  2018-03-20 10:11   ` Nikolay Borisov
  2018-03-20  9:53 ` [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum Anand Jain
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 16+ messages in thread
From: Anand Jain @ 2018-03-20  9:53 UTC (permalink / raw)
  To: linux-btrfs

%csum_type is being checked to check the number of csum types we support,
which is 1 as of now. Instead just check if the type matches with the
only type we support, that is BTRFS_CSUM_TYPE_CRC32. And further adds
cleanup.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 41 +++++++++++++++++++----------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1657d6aa4fa6..582ed6af3c50 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -399,32 +399,29 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	struct btrfs_super_block *disk_sb =
 		(struct btrfs_super_block *)raw_disk_sb;
 	u16 csum_type = btrfs_super_csum_type(disk_sb);
-	int ret = 0;
-
-	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
-		u32 crc = ~(u32)0;
-		char result[sizeof(crc)];
-
-		/*
-		 * The super_block structure does not span the whole
-		 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
-		 * is filled with zeros and is included in the checksum.
-		 */
-		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
-				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-		btrfs_csum_final(crc, result);
-
-		if (memcmp(raw_disk_sb, result, sizeof(result)))
-			ret = 1;
-	}
+	u32 crc = ~(u32)0;
+	char result[sizeof(crc)];
 
-	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
+	/* We support csum type crc32 only as of now */
+	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
 		btrfs_err(fs_info, "unsupported checksum algorithm %u",
-				csum_type);
-		ret = 1;
+			  csum_type);
+		return 1;
 	}
 
-	return ret;
+	/*
+	 * The super_block structure does not span the whole
+	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
+	 * is filled with zeros and is included in the checksum.
+	 */
+	crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
+			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+	btrfs_csum_final(crc, result);
+
+	if (memcmp(raw_disk_sb, result, sizeof(result)))
+		return 1;
+
+	return 0;
 }
 
 /*
-- 
2.15.0


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum
  2018-03-20  9:53 [PATCH 0/3] Preparatory to add the csum check in the scan context Anand Jain
  2018-03-20  9:53 ` [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
@ 2018-03-20  9:53 ` Anand Jain
  2018-03-20 10:13   ` Nikolay Borisov
  2018-03-20  9:53 ` [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan Anand Jain
  2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  3 siblings, 1 reply; 16+ messages in thread
From: Anand Jain @ 2018-03-20  9:53 UTC (permalink / raw)
  To: linux-btrfs

Return the required -EINVAL from the function btrfs_check_super_csum()
and move the error logging into the btrfs_check_super_csum() itself.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 582ed6af3c50..aafd836af61d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -406,7 +406,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
 		btrfs_err(fs_info, "unsupported checksum algorithm %u",
 			  csum_type);
-		return 1;
+		return -EINVAL;
 	}
 
 	/*
@@ -418,8 +418,10 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 	btrfs_csum_final(crc, result);
 
-	if (memcmp(raw_disk_sb, result, sizeof(result)))
-		return 1;
+	if (memcmp(raw_disk_sb, result, sizeof(result))) {
+		btrfs_err(fs_info, "superblock checksum mismatch");
+		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -2571,9 +2573,8 @@ int open_ctree(struct super_block *sb,
 	 * We want to check superblock checksum, the type is stored inside.
 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
 	 */
-	if (btrfs_check_super_csum(fs_info, bh->b_data)) {
-		btrfs_err(fs_info, "superblock checksum mismatch");
-		err = -EINVAL;
+	err = btrfs_check_super_csum(fs_info, bh->b_data);
+	if (err) {
 		brelse(bh);
 		goto fail_alloc;
 	}
-- 
2.15.0


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan
  2018-03-20  9:53 [PATCH 0/3] Preparatory to add the csum check in the scan context Anand Jain
  2018-03-20  9:53 ` [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
  2018-03-20  9:53 ` [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum Anand Jain
@ 2018-03-20  9:53 ` Anand Jain
  2018-03-20 11:10   ` Nikolay Borisov
  2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  3 siblings, 1 reply; 16+ messages in thread
From: Anand Jain @ 2018-03-20  9:53 UTC (permalink / raw)
  To: linux-btrfs

In preparation to use the function btrfs_check_super_csum() for
the device scan context, make it nonstatic and pass the
struct block_device instead of the struct fs_info.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 12 ++++++------
 fs/btrfs/disk-io.h |  1 +
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index aafd836af61d..d2ace2dca9de 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -393,8 +393,7 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
  * Return 0 if the superblock checksum type matches the checksum value of that
  * algorithm. Pass the raw disk superblock data.
  */
-static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
-				  char *raw_disk_sb)
+int btrfs_check_super_csum(struct block_device *bdev, char *raw_disk_sb)
 {
 	struct btrfs_super_block *disk_sb =
 		(struct btrfs_super_block *)raw_disk_sb;
@@ -404,8 +403,8 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 
 	/* We support csum type crc32 only as of now */
 	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
-		btrfs_err(fs_info, "unsupported checksum algorithm %u",
-			  csum_type);
+		pr_err("BTRFS error (device %pg): unsupported checksum algorithm %u",
+			bdev, csum_type);
 		return -EINVAL;
 	}
 
@@ -419,7 +418,8 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	btrfs_csum_final(crc, result);
 
 	if (memcmp(raw_disk_sb, result, sizeof(result))) {
-		btrfs_err(fs_info, "superblock checksum mismatch");
+		pr_err("BTRFS error (device %pg): superblock checksum mismatch",
+			bdev);
 		return -EINVAL;
 	}
 
@@ -2573,7 +2573,7 @@ int open_ctree(struct super_block *sb,
 	 * We want to check superblock checksum, the type is stored inside.
 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
 	 */
-	err = btrfs_check_super_csum(fs_info, bh->b_data);
+	err = btrfs_check_super_csum(fs_devices->latest_bdev, bh->b_data);
 	if (err) {
 		brelse(bh);
 		goto fail_alloc;
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 70a88d61b547..1427fa1181d4 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -69,6 +69,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
 			struct buffer_head **bh_ret);
+int btrfs_check_super_csum(struct block_device *bdev, char *raw_disk_sb);
 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
 				      struct btrfs_key *location);
-- 
2.15.0


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type
  2018-03-20  9:53 ` [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
@ 2018-03-20 10:11   ` Nikolay Borisov
  2018-03-20 10:12     ` Nikolay Borisov
  0 siblings, 1 reply; 16+ messages in thread
From: Nikolay Borisov @ 2018-03-20 10:11 UTC (permalink / raw)
  To: Anand Jain, linux-btrfs



On 20.03.2018 11:53, Anand Jain wrote:
> %csum_type is being checked to check the number of csum types we support,
> which is 1 as of now. Instead just check if the type matches with the
> only type we support, that is BTRFS_CSUM_TYPE_CRC32. And further adds
> cleanup.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  fs/btrfs/disk-io.c | 41 +++++++++++++++++++----------------------
>  1 file changed, 19 insertions(+), 22 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 1657d6aa4fa6..582ed6af3c50 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -399,32 +399,29 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  	struct btrfs_super_block *disk_sb =
>  		(struct btrfs_super_block *)raw_disk_sb;
>  	u16 csum_type = btrfs_super_csum_type(disk_sb);
> -	int ret = 0;
> -
> -	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
> -		u32 crc = ~(u32)0;
> -		char result[sizeof(crc)];
> -
> -		/*
> -		 * The super_block structure does not span the whole
> -		 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
> -		 * is filled with zeros and is included in the checksum.
> -		 */
> -		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
> -				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
> -		btrfs_csum_final(crc, result);
> -
> -		if (memcmp(raw_disk_sb, result, sizeof(result)))
> -			ret = 1;
> -	}
> +	u32 crc = ~(u32)0;
> +	char result[sizeof(crc)];
>  
> -	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
> +	/* We support csum type crc32 only as of now */
> +	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
>  		btrfs_err(fs_info, "unsupported checksum algorithm %u",
> -				csum_type);
> -		ret = 1;
> +			  csum_type);
> +		return 1;

I think it would make sense to return EINVAL here. Then the sole caller
of this function (open_ctree) can use the code a bit more idiomatically:

ret = btrfs_check_super_csum()

if (ret < 0) {
handle failure
}

Right now we return 1 on both when the function fails due to invalid CRC
algorithm and if the checksum doesn't match. And we are going to print 2
things: unsupported checksum algorithm and the
btrfs_err(fs_info, "superblock checksum mismatch");    from open_ctree.

Let's implemented proper error returning strategy for this function.



>  	}
>  
> -	return ret;
> +	/*
> +	 * The super_block structure does not span the whole
> +	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
> +	 * is filled with zeros and is included in the checksum.
> +	 */
> +	crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
> +			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
> +	btrfs_csum_final(crc, result);
> +
> +	if (memcmp(raw_disk_sb, result, sizeof(result)))
> +		return 1;

Perhaps return EUCLEAN i.e something is corrupted hence the checksum
didn't pan out as we expected.

> +
> +	return 0;
>  }
>  
>  /*
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type
  2018-03-20 10:11   ` Nikolay Borisov
@ 2018-03-20 10:12     ` Nikolay Borisov
  0 siblings, 0 replies; 16+ messages in thread
From: Nikolay Borisov @ 2018-03-20 10:12 UTC (permalink / raw)
  To: Anand Jain, linux-btrfs



On 20.03.2018 12:11, Nikolay Borisov wrote:
> 
> 
> On 20.03.2018 11:53, Anand Jain wrote:
>> %csum_type is being checked to check the number of csum types we support,
>> which is 1 as of now. Instead just check if the type matches with the
>> only type we support, that is BTRFS_CSUM_TYPE_CRC32. And further adds
>> cleanup.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>>  fs/btrfs/disk-io.c | 41 +++++++++++++++++++----------------------
>>  1 file changed, 19 insertions(+), 22 deletions(-)
>>
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> index 1657d6aa4fa6..582ed6af3c50 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -399,32 +399,29 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>>  	struct btrfs_super_block *disk_sb =
>>  		(struct btrfs_super_block *)raw_disk_sb;
>>  	u16 csum_type = btrfs_super_csum_type(disk_sb);
>> -	int ret = 0;
>> -
>> -	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
>> -		u32 crc = ~(u32)0;
>> -		char result[sizeof(crc)];
>> -
>> -		/*
>> -		 * The super_block structure does not span the whole
>> -		 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
>> -		 * is filled with zeros and is included in the checksum.
>> -		 */
>> -		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
>> -				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>> -		btrfs_csum_final(crc, result);
>> -
>> -		if (memcmp(raw_disk_sb, result, sizeof(result)))
>> -			ret = 1;
>> -	}
>> +	u32 crc = ~(u32)0;
>> +	char result[sizeof(crc)];
>>  
>> -	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
>> +	/* We support csum type crc32 only as of now */
>> +	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
>>  		btrfs_err(fs_info, "unsupported checksum algorithm %u",
>> -				csum_type);
>> -		ret = 1;
>> +			  csum_type);
>> +		return 1;
> 
> I think it would make sense to return EINVAL here. Then the sole caller
> of this function (open_ctree) can use the code a bit more idiomatically:
> 
> ret = btrfs_check_super_csum()
> 
> if (ret < 0) {
> handle failure
> }
> 
> Right now we return 1 on both when the function fails due to invalid CRC
> algorithm and if the checksum doesn't match. And we are going to print 2
> things: unsupported checksum algorithm and the
> btrfs_err(fs_info, "superblock checksum mismatch");    from open_ctree.
> 
> Let's implemented proper error returning strategy for this function.
> 

Disregard, you have already implemented something like that in 2/3. I
will comment there how it can be improved.

> 
> 
>>  	}
>>  
>> -	return ret;
>> +	/*
>> +	 * The super_block structure does not span the whole
>> +	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
>> +	 * is filled with zeros and is included in the checksum.
>> +	 */
>> +	crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
>> +			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>> +	btrfs_csum_final(crc, result);
>> +
>> +	if (memcmp(raw_disk_sb, result, sizeof(result)))
>> +		return 1;
> 
> Perhaps return EUCLEAN i.e something is corrupted hence the checksum
> didn't pan out as we expected.
> 
>> +
>> +	return 0;
>>  }
>>  
>>  /*
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum
  2018-03-20  9:53 ` [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum Anand Jain
@ 2018-03-20 10:13   ` Nikolay Borisov
  2018-03-20 22:23     ` Anand Jain
  2018-03-21  2:37     ` Anand Jain
  0 siblings, 2 replies; 16+ messages in thread
From: Nikolay Borisov @ 2018-03-20 10:13 UTC (permalink / raw)
  To: Anand Jain, linux-btrfs



On 20.03.2018 11:53, Anand Jain wrote:
> Return the required -EINVAL from the function btrfs_check_super_csum()
> and move the error logging into the btrfs_check_super_csum() itself.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  fs/btrfs/disk-io.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 582ed6af3c50..aafd836af61d 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -406,7 +406,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
>  		btrfs_err(fs_info, "unsupported checksum algorithm %u",
>  			  csum_type);
> -		return 1;
> +		return -EINVAL;
>  	}
>  
>  	/*
> @@ -418,8 +418,10 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>  	btrfs_csum_final(crc, result);
>  
> -	if (memcmp(raw_disk_sb, result, sizeof(result)))
> -		return 1;
> +	if (memcmp(raw_disk_sb, result, sizeof(result))) {
> +		btrfs_err(fs_info, "superblock checksum mismatch");
> +		return -EINVAL;

Don't we want EUCLEAN here, since an error in the checksum indicates
corruption?

> +	}
>  
>  	return 0;
>  }
> @@ -2571,9 +2573,8 @@ int open_ctree(struct super_block *sb,
>  	 * We want to check superblock checksum, the type is stored inside.
>  	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
>  	 */
> -	if (btrfs_check_super_csum(fs_info, bh->b_data)) {
> -		btrfs_err(fs_info, "superblock checksum mismatch");
> -		err = -EINVAL;
> +	err = btrfs_check_super_csum(fs_info, bh->b_data);
> +	if (err) {
>  		brelse(bh);
>  		goto fail_alloc;
>  	}
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan
  2018-03-20  9:53 ` [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan Anand Jain
@ 2018-03-20 11:10   ` Nikolay Borisov
  2018-03-20 22:32     ` Anand Jain
  0 siblings, 1 reply; 16+ messages in thread
From: Nikolay Borisov @ 2018-03-20 11:10 UTC (permalink / raw)
  To: Anand Jain, linux-btrfs



On 20.03.2018 11:53, Anand Jain wrote:
> In preparation to use the function btrfs_check_super_csum() for
> the device scan context, make it nonstatic and pass the
> struct block_device instead of the struct fs_info.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  fs/btrfs/disk-io.c | 12 ++++++------
>  fs/btrfs/disk-io.h |  1 +
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index aafd836af61d..d2ace2dca9de 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -393,8 +393,7 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
>   * Return 0 if the superblock checksum type matches the checksum value of that
>   * algorithm. Pass the raw disk superblock data.
>   */
> -static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
> -				  char *raw_disk_sb)
> +int btrfs_check_super_csum(struct block_device *bdev, char *raw_disk_sb)
>  {

Since this has become a public function and you've changed the fs_info
parameter to taking a bdev, which is not used for anything else than
printing the error I think it's appropriate to document which block
device should be passed to this function.

Also passing the block device only for printing purposes seems a bit odd.

>  	struct btrfs_super_block *disk_sb =
>  		(struct btrfs_super_block *)raw_disk_sb;
> @@ -404,8 +403,8 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  
>  	/* We support csum type crc32 only as of now */
>  	if (csum_type != BTRFS_CSUM_TYPE_CRC32) {
> -		btrfs_err(fs_info, "unsupported checksum algorithm %u",
> -			  csum_type);
> +		pr_err("BTRFS error (device %pg): unsupported checksum algorithm %u",
> +			bdev, csum_type);
>  		return -EINVAL;
>  	}
>  
> @@ -419,7 +418,8 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  	btrfs_csum_final(crc, result);
>  
>  	if (memcmp(raw_disk_sb, result, sizeof(result))) {
> -		btrfs_err(fs_info, "superblock checksum mismatch");
> +		pr_err("BTRFS error (device %pg): superblock checksum mismatch",
> +			bdev);
>  		return -EINVAL;
>  	}
>  
> @@ -2573,7 +2573,7 @@ int open_ctree(struct super_block *sb,
>  	 * We want to check superblock checksum, the type is stored inside.
>  	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
>  	 */
> -	err = btrfs_check_super_csum(fs_info, bh->b_data);
> +	err = btrfs_check_super_csum(fs_devices->latest_bdev, bh->b_data);
>  	if (err) {
>  		brelse(bh);
>  		goto fail_alloc;
> diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
> index 70a88d61b547..1427fa1181d4 100644
> --- a/fs/btrfs/disk-io.h
> +++ b/fs/btrfs/disk-io.h
> @@ -69,6 +69,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
>  struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
>  int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
>  			struct buffer_head **bh_ret);
> +int btrfs_check_super_csum(struct block_device *bdev, char *raw_disk_sb);
>  int btrfs_commit_super(struct btrfs_fs_info *fs_info);
>  struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
>  				      struct btrfs_key *location);
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum
  2018-03-20 10:13   ` Nikolay Borisov
@ 2018-03-20 22:23     ` Anand Jain
  2018-03-21  2:37     ` Anand Jain
  1 sibling, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-20 22:23 UTC (permalink / raw)
  To: Nikolay Borisov, linux-btrfs




>> @@ -418,8 +418,10 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>>   			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>>   	btrfs_csum_final(crc, result);
>>   
>> -	if (memcmp(raw_disk_sb, result, sizeof(result)))
>> -		return 1;
>> +	if (memcmp(raw_disk_sb, result, sizeof(result))) {
>> +		btrfs_err(fs_info, "superblock checksum mismatch");
>> +		return -EINVAL;
> 
> Don't we want EUCLEAN here, since an error in the checksum indicates
> corruption?

  yeah, I struggled with it before.
  Strangely there isn't an error code for the csum error
  when csum being widely used in the computer systems.

  Our closest are:

#define	EFAULT		14	/* Bad address */
#define	EUCLEAN		135	/* Structure needs cleaning */

  Will use the suggested EUCLEAN.

Thanks, Anand

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan
  2018-03-20 11:10   ` Nikolay Borisov
@ 2018-03-20 22:32     ` Anand Jain
  0 siblings, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-20 22:32 UTC (permalink / raw)
  To: Nikolay Borisov, linux-btrfs



On 03/20/2018 07:10 PM, Nikolay Borisov wrote:
> 
> 
> On 20.03.2018 11:53, Anand Jain wrote:
>> In preparation to use the function btrfs_check_super_csum() for
>> the device scan context, make it nonstatic and pass the
>> struct block_device instead of the struct fs_info.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>>   fs/btrfs/disk-io.c | 12 ++++++------
>>   fs/btrfs/disk-io.h |  1 +
>>   2 files changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> index aafd836af61d..d2ace2dca9de 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -393,8 +393,7 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
>>    * Return 0 if the superblock checksum type matches the checksum value of that
>>    * algorithm. Pass the raw disk superblock data.
>>    */
>> -static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>> -				  char *raw_disk_sb)
>> +int btrfs_check_super_csum(struct block_device *bdev, char *raw_disk_sb)
>>   {
> 
> Since this has become a public function and you've changed the fs_info
> parameter to taking a bdev, which is not used for anything else than
> printing the error I think it's appropriate to document which block
> device should be passed to this function.
> 
> Also passing the block device only for printing purposes seems a bit odd.

  Its the device on which we have read the superblock. I find it
  odd too. Will do that pr_err on the parent function. Will add
  comments to the public function.


Thanks, Anand


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum
  2018-03-20 10:13   ` Nikolay Borisov
  2018-03-20 22:23     ` Anand Jain
@ 2018-03-21  2:37     ` Anand Jain
  2018-03-21  3:01       ` Anand Jain
  1 sibling, 1 reply; 16+ messages in thread
From: Anand Jain @ 2018-03-21  2:37 UTC (permalink / raw)
  To: Nikolay Borisov, linux-btrfs



>> @@ -418,8 +418,10 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>>   			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>>   	btrfs_csum_final(crc, result);
>>   
>> -	if (memcmp(raw_disk_sb, result, sizeof(result)))
>> -		return 1;
>> +	if (memcmp(raw_disk_sb, result, sizeof(result))) {
>> +		btrfs_err(fs_info, "superblock checksum mismatch");
>> +		return -EINVAL;
> 
> Don't we want EUCLEAN here, since an error in the checksum indicates
> corruption?

  With the v2 patch sentout here is the error str that is seen on the cli.

   mount: mount /dev/sdb on /btrfs failed: Structure needs cleaning

I am ok. However would have much better if it says checksum error.

Do you/anyone suggest I should update the errno.h?

Thanks, Anand

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum
  2018-03-21  2:37     ` Anand Jain
@ 2018-03-21  3:01       ` Anand Jain
  0 siblings, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-21  3:01 UTC (permalink / raw)
  To: Nikolay Borisov, linux-btrfs



On 03/21/2018 10:37 AM, Anand Jain wrote:
> 
> 
>>> @@ -418,8 +418,10 @@ static int btrfs_check_super_csum(struct 
>>> btrfs_fs_info *fs_info,
>>>                     crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
>>>       btrfs_csum_final(crc, result);
>>> -    if (memcmp(raw_disk_sb, result, sizeof(result)))
>>> -        return 1;
>>> +    if (memcmp(raw_disk_sb, result, sizeof(result))) {
>>> +        btrfs_err(fs_info, "superblock checksum mismatch");
>>> +        return -EINVAL;
>>
>> Don't we want EUCLEAN here, since an error in the checksum indicates
>> corruption?
> 
>   With the v2 patch sentout here is the error str that is seen on the cli.
> 
>    mount: mount /dev/sdb on /btrfs failed: Structure needs cleaning

  And since we return -EINVAL for the error csum_type not found we get..

  mount: wrong fs type, bad option, bad superblock on /dev/sdb,
        missing codepage or helper program, or other error

        In some cases useful info is found in syslog - try
        dmesg | tail or so.

  Looks like mount syscall interprets -EINVAL error.

> I am ok. However would have much better if it says checksum error.

  Also we may need an error code to say incompatible disk format/version.

> Do you/anyone suggest I should update the errno.h?

Thanks, Anand

> 
> Thanks, Anand
> -- 
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v3 0/2] Preparatory to add the csum check in the scan context
@ 2018-03-21  8:14 ` Anand Jain
  2018-03-21  8:14   ` [PATCH v3 1/2] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
                     ` (2 more replies)
  0 siblings, 3 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-21  8:14 UTC (permalink / raw)
  To: linux-btrfs

v2->v3:
 1/2: Keep the check %(csum_type >= ARRAY_SIZE(btrfs_csum_sizes))
      because it is inline to support future expansion, further
      btrfs-progs is already copied it.
 2/2: Drop pr_err for default error which won't be possible.

v1->v2:
  Merge 2/3 and 3/3
  Use -EUCLEAN for csum mismatch
  Move the error logging to the parent function
  Drop the struct btrfs_fsinfo as the argument for
        btrfs_check_super_csum()
  Do not make btrfs_check_super_csum() nonstatic here, it will be part
        of the patchset which will use the csum in the scan context

Anand Jain (2):
  btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the
    type
  btrfs: return required error from btrfs_check_super_csum

 fs/btrfs/disk-io.c | 53 ++++++++++++++++++++++++++---------------------------
 1 file changed, 26 insertions(+), 27 deletions(-)

-- 
2.15.0


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v3 1/2] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type
  2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
@ 2018-03-21  8:14   ` Anand Jain
  2018-03-21  8:14   ` [PATCH v3 2/2] btrfs: return required error from btrfs_check_super_csum Anand Jain
  2018-03-26  6:40   ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  2 siblings, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-21  8:14 UTC (permalink / raw)
  To: linux-btrfs

%csum_type is being checked to check the number of csum types we support,
which is 1 as of now. Instead just check if the type matches with the
only type we support, that is BTRFS_CSUM_TYPE_CRC32. And further adds
cleanup.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 38 +++++++++++++++++---------------------
 1 file changed, 17 insertions(+), 21 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1657d6aa4fa6..b9b435579527 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -399,32 +399,28 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	struct btrfs_super_block *disk_sb =
 		(struct btrfs_super_block *)raw_disk_sb;
 	u16 csum_type = btrfs_super_csum_type(disk_sb);
-	int ret = 0;
-
-	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
-		u32 crc = ~(u32)0;
-		char result[sizeof(crc)];
-
-		/*
-		 * The super_block structure does not span the whole
-		 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
-		 * is filled with zeros and is included in the checksum.
-		 */
-		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
-				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-		btrfs_csum_final(crc, result);
-
-		if (memcmp(raw_disk_sb, result, sizeof(result)))
-			ret = 1;
-	}
+	u32 crc = ~(u32)0;
+	char result[sizeof(crc)];
 
 	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
 		btrfs_err(fs_info, "unsupported checksum algorithm %u",
-				csum_type);
-		ret = 1;
+			  csum_type);
+		return 1;
 	}
 
-	return ret;
+	/*
+	 * The super_block structure does not span the whole
+	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
+	 * is filled with zeros and is included in the checksum.
+	 */
+	crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
+			      crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+	btrfs_csum_final(crc, result);
+
+	if (memcmp(raw_disk_sb, result, sizeof(result)))
+		return 1;
+
+	return 0;
 }
 
 /*
-- 
2.15.0


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v3 2/2] btrfs: return required error from btrfs_check_super_csum
  2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  2018-03-21  8:14   ` [PATCH v3 1/2] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
@ 2018-03-21  8:14   ` Anand Jain
  2018-03-26  6:40   ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  2 siblings, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-21  8:14 UTC (permalink / raw)
  To: linux-btrfs

Return the required -EINVAL and -EUCLEAN from the function
btrfs_check_super_csum(). And more the error log into the
parent function.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/disk-io.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b9b435579527..062b3e0c7fd1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -392,9 +392,10 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 /*
  * Return 0 if the superblock checksum type matches the checksum value of that
  * algorithm. Pass the raw disk superblock data.
+ * Otherwise: -EINVAL  if csum type is not found
+ * 	      -EUCLEAN if csum does not match
  */
-static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
-				  char *raw_disk_sb)
+static int btrfs_check_super_csum(char *raw_disk_sb)
 {
 	struct btrfs_super_block *disk_sb =
 		(struct btrfs_super_block *)raw_disk_sb;
@@ -402,11 +403,8 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	u32 crc = ~(u32)0;
 	char result[sizeof(crc)];
 
-	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
-		btrfs_err(fs_info, "unsupported checksum algorithm %u",
-			  csum_type);
-		return 1;
-	}
+	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes))
+		return -EINVAL;
 
 	/*
 	 * The super_block structure does not span the whole
@@ -418,7 +416,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 	btrfs_csum_final(crc, result);
 
 	if (memcmp(raw_disk_sb, result, sizeof(result)))
-		return 1;
+		return -EUCLEAN;
 
 	return 0;
 }
@@ -2570,9 +2568,14 @@ int open_ctree(struct super_block *sb,
 	 * We want to check superblock checksum, the type is stored inside.
 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
 	 */
-	if (btrfs_check_super_csum(fs_info, bh->b_data)) {
-		btrfs_err(fs_info, "superblock checksum mismatch");
-		err = -EINVAL;
+	err = btrfs_check_super_csum(bh->b_data);
+	if (err) {
+		if (err == -EINVAL)
+			pr_err("BTRFS error (device %pg): unsupported checksum algorithm",
+				fs_devices->latest_bdev);
+		else if (err == -EUCLEAN)
+			pr_err("BTRFS error (device %pg): superblock checksum mismatch",
+				fs_devices->latest_bdev);
 		brelse(bh);
 		goto fail_alloc;
 	}
-- 
2.15.0


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH v3 0/2] Preparatory to add the csum check in the scan context
  2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
  2018-03-21  8:14   ` [PATCH v3 1/2] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
  2018-03-21  8:14   ` [PATCH v3 2/2] btrfs: return required error from btrfs_check_super_csum Anand Jain
@ 2018-03-26  6:40   ` Anand Jain
  2 siblings, 0 replies; 16+ messages in thread
From: Anand Jain @ 2018-03-26  6:40 UTC (permalink / raw)
  To: linux-btrfs



  Pls, ignore this bunch as I have included this with other cleanups.

Thanks, Anand


On 03/21/2018 04:14 PM, Anand Jain wrote:
> v2->v3:
>   1/2: Keep the check %(csum_type >= ARRAY_SIZE(btrfs_csum_sizes))
>        because it is inline to support future expansion, further
>        btrfs-progs is already copied it.
>   2/2: Drop pr_err for default error which won't be possible.
> 
> v1->v2:
>    Merge 2/3 and 3/3
>    Use -EUCLEAN for csum mismatch
>    Move the error logging to the parent function
>    Drop the struct btrfs_fsinfo as the argument for
>          btrfs_check_super_csum()
>    Do not make btrfs_check_super_csum() nonstatic here, it will be part
>          of the patchset which will use the csum in the scan context
> 
> Anand Jain (2):
>    btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the
>      type
>    btrfs: return required error from btrfs_check_super_csum
> 
>   fs/btrfs/disk-io.c | 53 ++++++++++++++++++++++++++---------------------------
>   1 file changed, 26 insertions(+), 27 deletions(-)
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, other threads:[~2018-03-26  6:38 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-03-20  9:53 [PATCH 0/3] Preparatory to add the csum check in the scan context Anand Jain
2018-03-20  9:53 ` [PATCH 1/3] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
2018-03-20 10:11   ` Nikolay Borisov
2018-03-20 10:12     ` Nikolay Borisov
2018-03-20  9:53 ` [PATCH 2/3] btrfs: return required error from btrfs_check_super_csum Anand Jain
2018-03-20 10:13   ` Nikolay Borisov
2018-03-20 22:23     ` Anand Jain
2018-03-21  2:37     ` Anand Jain
2018-03-21  3:01       ` Anand Jain
2018-03-20  9:53 ` [PATCH 3/3] btrfs: refactor btrfs_check_super_csum() for scan Anand Jain
2018-03-20 11:10   ` Nikolay Borisov
2018-03-20 22:32     ` Anand Jain
2018-03-21  8:14 ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain
2018-03-21  8:14   ` [PATCH v3 1/2] btrfs: cleanup btrfs_check_super_csum() to check the csum_type to the type Anand Jain
2018-03-21  8:14   ` [PATCH v3 2/2] btrfs: return required error from btrfs_check_super_csum Anand Jain
2018-03-26  6:40   ` [PATCH v3 0/2] Preparatory to add the csum check in the scan context Anand Jain

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