[PATCH 0/2] btrfs: tree-checker: Add checks to detect missing INODE_ITEM

[PATCH 0/2] btrfs: tree-checker: Add checks to detect missing INODE_ITEM

[Qu Wenruo]

For the following items, key->objectid is inode number:
- DIR_ITEM
- DIR_INDEX
- XATTR_ITEM
- EXTENT_DATA
- INODE_REF

So in btrfs btree, such items must have its previous item shares the
same objectid, e.g.:
 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 INODE_ITEM 0)
 (258 INODE_REF 0)
 (258 XATTR_ITEM 0)
 (258 EXTENT_DATA 0)

But if we have the following sequence, then there is definitely
something wrong, normally some INODE_ITEM is missing, like:
 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 XATTR_ITEM 0)  <<< objecitd suddenly changed to 258
 (258 EXTENT_DATA 0)

So just by checking the previous key for above inode based key types, we
can detect missing inode item.

In this patchset, we will enhance existing check_dir_item() and
check_extent_data_item() to detect missing INODE_ITEM first, then add
INODE_REF checker.

So now we can cover the INODE_ITEM missing case in tree-checker without
much cost, but achieve the check which is normally done by btrfs-check.
(I'm already a little concerned about the fact that kernel tree-checker
is getting stronger and stronger while btrfs-progs can't fix all
problems)

Of course, there is still a limitation that the first key of a leaf
can't be verified, but we have already cover all the rest keys, which is
way better than "good enough"(TM).

Qu Wenruo (2):
  btrfs: tree-checker: Try to detect missing INODE_ITEM
  btrfs: tree-checker: Add check for INODE_REF

 fs/btrfs/tree-checker.c | 78 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 76 insertions(+), 2 deletions(-)

-- 
2.23.0

[PATCH 1/2] btrfs: tree-checker: Try to detect missing INODE_ITEM

[Qu Wenruo]

For the following items, key->objectid is inode number:
- DIR_ITEM
- DIR_INDEX
- XATTR_ITEM
- EXTENT_DATA
- INODE_REF

So in btrfs btree, such items must have its previous item shares the
same objectid, e.g.:
 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 INODE_ITEM 0)
 (258 INODE_REF 0)
 (258 XATTR_ITEM 0)
 (258 EXTENT_DATA 0)

But if we have the following sequence, then there is definitely
something wrong, normally some INODE_ITEM is missing, like:
 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 XATTR_ITEM 0)  <<< objecitd suddenly changed to 258
 (258 EXTENT_DATA 0)

So just by checking the previous key for above inode based key types, we
can detect missing inode item.

For INODE_REF key type, the check will be added along with INODE_REF
checker.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/tree-checker.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index ccd5706199d7..636ce1b4566e 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -141,6 +141,19 @@ static int check_extent_data_item(struct extent_buffer *leaf,
 		return -EUCLEAN;
 	}
 
+	/*
+	 * Previous key must have the same key->objectid (ino).
+	 * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
+	 * But if objectids mismatch, it means we have a missing
+	 * INODE_ITEM.
+	 */
+	if (slot > 0 && prev_key->objectid != key->objectid) {
+		file_extent_err(leaf, slot,
+		"invalid previous key objectid, have %llu expect %llu",
+				prev_key->objectid, key->objectid);
+		return -EUCLEAN;
+	}
+
 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 
 	if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
@@ -299,13 +312,21 @@ static void dir_item_err(const struct extent_buffer *eb, int slot,
 }
 
 static int check_dir_item(struct extent_buffer *leaf,
-			  struct btrfs_key *key, int slot)
+			  struct btrfs_key *key, struct btrfs_key *prev_key,
+			  int slot)
 {
 	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_dir_item *di;
 	u32 item_size = btrfs_item_size_nr(leaf, slot);
 	u32 cur = 0;
 
+	/* Same check as in check_extent_data_item() */
+	if (slot > 0 && prev_key->objectid != key->objectid) {
+		dir_item_err(leaf, slot,
+		"invalid previous key objectid, have %llu expect %llu",
+			     prev_key->objectid, key->objectid);
+		return -EUCLEAN;
+	}
 	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 	while (cur < item_size) {
 		u32 name_len;
@@ -841,7 +862,7 @@ static int check_leaf_item(struct extent_buffer *leaf,
 	case BTRFS_DIR_ITEM_KEY:
 	case BTRFS_DIR_INDEX_KEY:
 	case BTRFS_XATTR_ITEM_KEY:
-		ret = check_dir_item(leaf, key, slot);
+		ret = check_dir_item(leaf, key, prev_key, slot);
 		break;
 	case BTRFS_BLOCK_GROUP_ITEM_KEY:
 		ret = check_block_group_item(leaf, key, slot);
-- 
2.23.0

[PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[Qu Wenruo]

For INODE_REF we will check:
- Objectid (ino) against previous key
  To detect missing INODE_ITEM.

- No overflow/padding in the data payload
  Much like DIR_ITEM, but with less members to check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 636ce1b4566e..3ce447eb591c 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
 	return 0;
 }
 
+#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
+	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)
+static int check_inode_ref(struct extent_buffer *leaf,
+			   struct btrfs_key *key, struct btrfs_key *prev_key,
+			   int slot)
+{
+	struct btrfs_inode_ref *iref;
+	unsigned long ptr;
+	unsigned long end;
+
+	/* namelen can't be 0, so item_size == sizeof() is also invalid */
+	if (btrfs_item_size_nr(leaf, slot) <= sizeof(*iref)) {
+		inode_ref_err(fs_info, leaf, slot,
+		"invalid item size, have %u expect (%zu, %u)",
+			btrfs_item_size_nr(leaf, slot),
+			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
+		return -EUCLEAN;
+	}
+
+	ptr = btrfs_item_ptr_offset(leaf, slot);
+	end = ptr + btrfs_item_size_nr(leaf, slot);
+	while (ptr < end) {
+		u16 namelen;
+
+		if (ptr + sizeof(iref) > end) {
+			inode_ref_err(fs_info, leaf, slot,
+		"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
+				ptr, end, sizeof(iref));
+			return -EUCLEAN;
+		}
+
+		iref = (struct btrfs_inode_ref *)ptr;
+		namelen = btrfs_inode_ref_name_len(leaf, iref);
+		if (ptr + sizeof(*iref) + namelen > end) {
+			inode_ref_err(fs_info, leaf, slot,
+		"inode ref overflow, ptr %lu end %lu namelen %u",
+				ptr, end, namelen);
+			return -EUCLEAN;
+		}
+
+		/*
+		 * NOTE: In theory we should record all found index number
+		 * to find any duplicated index. But that will be too time
+		 * consuming for inodes with too many hard links.
+		 */
+		ptr += sizeof(*iref) + namelen;
+	}
+	return 0;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
@@ -864,6 +914,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
 	case BTRFS_XATTR_ITEM_KEY:
 		ret = check_dir_item(leaf, key, prev_key, slot);
 		break;
+	case BTRFS_INODE_REF_KEY:
+		ret = check_inode_ref(leaf, key, prev_key, slot);
+		break;
 	case BTRFS_BLOCK_GROUP_ITEM_KEY:
 		ret = check_block_group_item(leaf, key, slot);
 		break;
-- 
2.23.0

Re: [PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[Nikolay Borisov]

On 26.08.19 г. 10:40 ч., Qu Wenruo wrote:
> For INODE_REF we will check:
> - Objectid (ino) against previous key
>   To detect missing INODE_ITEM.
> 
> - No overflow/padding in the data payload
>   Much like DIR_ITEM, but with less members to check.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 636ce1b4566e..3ce447eb591c 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
>  	return 0;
>  }
>  
> +#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
> +	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)

This define doesn't bring anything, just opencode the call to
inode_item_err directly.

> +static int check_inode_ref(struct extent_buffer *leaf,
> +			   struct btrfs_key *key, struct btrfs_key *prev_key,
> +			   int slot)
> +{
> +	struct btrfs_inode_ref *iref;
> +	unsigned long ptr;
> +	unsigned long end;
> +
> +	/* namelen can't be 0, so item_size == sizeof() is also invalid */
> +	if (btrfs_item_size_nr(leaf, slot) <= sizeof(*iref)) {
> +		inode_ref_err(fs_info, leaf, slot,
> +		"invalid item size, have %u expect (%zu, %u)",
> +			btrfs_item_size_nr(leaf, slot),
> +			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
> +		return -EUCLEAN;
> +	}
> +
> +	ptr = btrfs_item_ptr_offset(leaf, slot);
> +	end = ptr + btrfs_item_size_nr(leaf, slot);
> +	while (ptr < end) {
> +		u16 namelen;
> +
> +		if (ptr + sizeof(iref) > end) {
> +			inode_ref_err(fs_info, leaf, slot,
> +		"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
> +				ptr, end, sizeof(iref));
> +			return -EUCLEAN;
> +		}
> +
> +		iref = (struct btrfs_inode_ref *)ptr;
> +		namelen = btrfs_inode_ref_name_len(leaf, iref);
> +		if (ptr + sizeof(*iref) + namelen > end) {
> +			inode_ref_err(fs_info, leaf, slot,
> +		"inode ref overflow, ptr %lu end %lu namelen %u",
> +				ptr, end, namelen);
> +			return -EUCLEAN;
> +		}
> +
> +		/*
> +		 * NOTE: In theory we should record all found index number
> +		 * to find any duplicated index. But that will be too time
> +		 * consuming for inodes with too many hard links.
> +		 */
> +		ptr += sizeof(*iref) + namelen;
> +	}
> +	return 0;
> +}
> +
>  /*
>   * Common point to switch the item-specific validation.
>   */
> @@ -864,6 +914,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
>  	case BTRFS_XATTR_ITEM_KEY:
>  		ret = check_dir_item(leaf, key, prev_key, slot);
>  		break;
> +	case BTRFS_INODE_REF_KEY:
> +		ret = check_inode_ref(leaf, key, prev_key, slot);
> +		break;
>  	case BTRFS_BLOCK_GROUP_ITEM_KEY:
>  		ret = check_block_group_item(leaf, key, slot);
>  		break;
> 

Re: [PATCH 1/2] btrfs: tree-checker: Try to detect missing INODE_ITEM

[Nikolay Borisov]

On 26.08.19 г. 10:40 ч., Qu Wenruo wrote:
> For the following items, key->objectid is inode number:
> - DIR_ITEM
> - DIR_INDEX
> - XATTR_ITEM
> - EXTENT_DATA
> - INODE_REF
> 
> So in btrfs btree, such items must have its previous item shares the
> same objectid, e.g.:
>  (257 INODE_ITEM 0)
>  (257 DIR_INDEX xxx)
>  (257 DIR_ITEM xxx)
>  (258 INODE_ITEM 0)
>  (258 INODE_REF 0)
>  (258 XATTR_ITEM 0)
>  (258 EXTENT_DATA 0)
> 
> But if we have the following sequence, then there is definitely
> something wrong, normally some INODE_ITEM is missing, like:
>  (257 INODE_ITEM 0)
>  (257 DIR_INDEX xxx)
>  (257 DIR_ITEM xxx)
>  (258 XATTR_ITEM 0)  <<< objecitd suddenly changed to 258
>  (258 EXTENT_DATA 0)
> 
> So just by checking the previous key for above inode based key types, we
> can detect missing inode item.
> 
> For INODE_REF key type, the check will be added along with INODE_REF
> checker.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/tree-checker.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index ccd5706199d7..636ce1b4566e 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -141,6 +141,19 @@ static int check_extent_data_item(struct extent_buffer *leaf,
>  		return -EUCLEAN;
>  	}
>  
> +	/*
> +	 * Previous key must have the same key->objectid (ino).
> +	 * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
> +	 * But if objectids mismatch, it means we have a missing
> +	 * INODE_ITEM.
> +	 */
> +	if (slot > 0 && prev_key->objectid != key->objectid) {
> +		file_extent_err(leaf, slot,
> +		"invalid previous key objectid, have %llu expect %llu",
> +				prev_key->objectid, key->objectid);
> +		return -EUCLEAN;
> +	}
> +
>  	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
>  
>  	if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
> @@ -299,13 +312,21 @@ static void dir_item_err(const struct extent_buffer *eb, int slot,
>  }
>  
>  static int check_dir_item(struct extent_buffer *leaf,
> -			  struct btrfs_key *key, int slot)
> +			  struct btrfs_key *key, struct btrfs_key *prev_key,
> +			  int slot)
>  {
>  	struct btrfs_fs_info *fs_info = leaf->fs_info;
>  	struct btrfs_dir_item *di;
>  	u32 item_size = btrfs_item_size_nr(leaf, slot);
>  	u32 cur = 0;
>  
> +	/* Same check as in check_extent_data_item() */
> +	if (slot > 0 && prev_key->objectid != key->objectid) {
> +		dir_item_err(leaf, slot,
> +		"invalid previous key objectid, have %llu expect %llu",
> +			     prev_key->objectid, key->objectid);
> +		return -EUCLEAN;
> +	}
>  	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
>  	while (cur < item_size) {
>  		u32 name_len;
> @@ -841,7 +862,7 @@ static int check_leaf_item(struct extent_buffer *leaf,
>  	case BTRFS_DIR_ITEM_KEY:
>  	case BTRFS_DIR_INDEX_KEY:
>  	case BTRFS_XATTR_ITEM_KEY:
> -		ret = check_dir_item(leaf, key, slot);
> +		ret = check_dir_item(leaf, key, prev_key, slot);
>  		break;
>  	case BTRFS_BLOCK_GROUP_ITEM_KEY:
>  		ret = check_block_group_item(leaf, key, slot);
> 

Re: [PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[Qu Wenruo]

On 2019/8/26 下午7:45, Nikolay Borisov wrote:
>
>
> On 26.08.19 г. 10:40 ч., Qu Wenruo wrote:
>> For INODE_REF we will check:
>> - Objectid (ino) against previous key
>>   To detect missing INODE_ITEM.
>>
>> - No overflow/padding in the data payload
>>   Much like DIR_ITEM, but with less members to check.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 53 insertions(+)
>>
>> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
>> index 636ce1b4566e..3ce447eb591c 100644
>> --- a/fs/btrfs/tree-checker.c
>> +++ b/fs/btrfs/tree-checker.c
>> @@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
>>  	return 0;
>>  }
>>
>> +#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
>> +	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)
>
> This define doesn't bring anything, just opencode the call to
> inode_item_err directly.

I could argue we that in an inode ref context, using a inode_item_err()
doesn't look right.

And since it's doesn't do any hurt, I prefer to make the error message
parse to match the context.

Thanks,
Qu
>
>> +static int check_inode_ref(struct extent_buffer *leaf,
>> +			   struct btrfs_key *key, struct btrfs_key *prev_key,
>> +			   int slot)
>> +{
>> +	struct btrfs_inode_ref *iref;
>> +	unsigned long ptr;
>> +	unsigned long end;
>> +
>> +	/* namelen can't be 0, so item_size == sizeof() is also invalid */
>> +	if (btrfs_item_size_nr(leaf, slot) <= sizeof(*iref)) {
>> +		inode_ref_err(fs_info, leaf, slot,
>> +		"invalid item size, have %u expect (%zu, %u)",
>> +			btrfs_item_size_nr(leaf, slot),
>> +			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
>> +		return -EUCLEAN;
>> +	}
>> +
>> +	ptr = btrfs_item_ptr_offset(leaf, slot);
>> +	end = ptr + btrfs_item_size_nr(leaf, slot);
>> +	while (ptr < end) {
>> +		u16 namelen;
>> +
>> +		if (ptr + sizeof(iref) > end) {
>> +			inode_ref_err(fs_info, leaf, slot,
>> +		"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
>> +				ptr, end, sizeof(iref));
>> +			return -EUCLEAN;
>> +		}
>> +
>> +		iref = (struct btrfs_inode_ref *)ptr;
>> +		namelen = btrfs_inode_ref_name_len(leaf, iref);
>> +		if (ptr + sizeof(*iref) + namelen > end) {
>> +			inode_ref_err(fs_info, leaf, slot,
>> +		"inode ref overflow, ptr %lu end %lu namelen %u",
>> +				ptr, end, namelen);
>> +			return -EUCLEAN;
>> +		}
>> +
>> +		/*
>> +		 * NOTE: In theory we should record all found index number
>> +		 * to find any duplicated index. But that will be too time
>> +		 * consuming for inodes with too many hard links.
>> +		 */
>> +		ptr += sizeof(*iref) + namelen;
>> +	}
>> +	return 0;
>> +}
>> +
>>  /*
>>   * Common point to switch the item-specific validation.
>>   */
>> @@ -864,6 +914,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
>>  	case BTRFS_XATTR_ITEM_KEY:
>>  		ret = check_dir_item(leaf, key, prev_key, slot);
>>  		break;
>> +	case BTRFS_INODE_REF_KEY:
>> +		ret = check_inode_ref(leaf, key, prev_key, slot);
>> +		break;
>>  	case BTRFS_BLOCK_GROUP_ITEM_KEY:
>>  		ret = check_block_group_item(leaf, key, slot);
>>  		break;
>>

Re: [PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[David Sterba]

On Mon, Aug 26, 2019 at 07:50:03PM +0800, Qu Wenruo wrote:
> 
> 
> On 2019/8/26 下午7:45, Nikolay Borisov wrote:
> >
> >
> > On 26.08.19 г. 10:40 ч., Qu Wenruo wrote:
> >> For INODE_REF we will check:
> >> - Objectid (ino) against previous key
> >>   To detect missing INODE_ITEM.
> >>
> >> - No overflow/padding in the data payload
> >>   Much like DIR_ITEM, but with less members to check.
> >>
> >> Signed-off-by: Qu Wenruo <wqu@suse.com>
> >> ---
> >>  fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 53 insertions(+)
> >>
> >> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> >> index 636ce1b4566e..3ce447eb591c 100644
> >> --- a/fs/btrfs/tree-checker.c
> >> +++ b/fs/btrfs/tree-checker.c
> >> @@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
> >>  	return 0;
> >>  }
> >>
> >> +#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
> >> +	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)
> >
> > This define doesn't bring anything, just opencode the call to
> > inode_item_err directly.
> 
> I could argue we that in an inode ref context, using a inode_item_err()
> doesn't look right.
> 
> And since it's doesn't do any hurt, I prefer to make the error message
> parse to match the context.

I agree the alias inode_ref_err does not hurt, there's no penatly in the
code so for sake of readability let's do it.

Re: [PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[David Sterba]

On Mon, Aug 26, 2019 at 03:40:39PM +0800, Qu Wenruo wrote:
> For INODE_REF we will check:
> - Objectid (ino) against previous key
>   To detect missing INODE_ITEM.
> 
> - No overflow/padding in the data payload
>   Much like DIR_ITEM, but with less members to check.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 636ce1b4566e..3ce447eb591c 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
>  	return 0;
>  }
>  
> +#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
> +	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)

I've changed that to

#define inode_ref_err(fs_info, eb, slot, fmt, args...)		\
	inode_item_err(fs_info, eb, slot, fmt, ##args)

as this is the common style for the variable macro args used in btrfs.