diff mbox series

[1/3] btrfs: rst: remove encoding field from stripe_extent

Message ID 20240610-b4-rst-updates-v1-1-179c1eec08f2@kernel.org (mailing list archive)
State New, archived
Headers show
Series btrfs: rst: updates for RAID stripe tree | expand

Commit Message

Johannes Thumshirn June 10, 2024, 8:40 a.m. UTC 
From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Remove the encoding field from 'struct btrfs_stripe_extent'. It was
originally intended to encode the RAID type as well as if we're a data
or a parity stripe.

But the RAID type can be inferred form the block-group and the data vs.
parity differentiation can be done easier with adding a new key type
for parity stripes in the RAID stripe tree.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 fs/btrfs/accessors.h            |  3 ---
 fs/btrfs/print-tree.c           |  5 -----
 fs/btrfs/raid-stripe-tree.c     | 13 -------------
 fs/btrfs/raid-stripe-tree.h     |  3 +--
 fs/btrfs/tree-checker.c         | 19 -------------------
 include/uapi/linux/btrfs_tree.h | 14 +-------------
 6 files changed, 2 insertions(+), 55 deletions(-)

Comments

David Sterba June 11, 2024, 2:36 p.m. UTC | #1 
On Mon, Jun 10, 2024 at 10:40:25AM +0200, Johannes Thumshirn wrote:
> -#define BTRFS_STRIPE_RAID5	5
> -#define BTRFS_STRIPE_RAID6	6
> -#define BTRFS_STRIPE_RAID1C3	7
> -#define BTRFS_STRIPE_RAID1C4	8
> -
>  struct btrfs_stripe_extent {
> -	__u8 encoding;
> -	__u8 reserved[7];
>  	/* An array of raid strides this stripe is composed of. */
> -	struct btrfs_raid_stride strides[];
> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);

Is there a reason to use the __ underscore macro? I see no difference
between that and DECLARE_FLEX_ARRAY and underscore usually means that
it's special in some way.
Johannes Thumshirn June 11, 2024, 4:33 p.m. UTC | #2 
On 11.06.24 16:37, David Sterba wrote:
> On Mon, Jun 10, 2024 at 10:40:25AM +0200, Johannes Thumshirn wrote:
>> -#define BTRFS_STRIPE_RAID5	5
>> -#define BTRFS_STRIPE_RAID6	6
>> -#define BTRFS_STRIPE_RAID1C3	7
>> -#define BTRFS_STRIPE_RAID1C4	8
>> -
>>   struct btrfs_stripe_extent {
>> -	__u8 encoding;
>> -	__u8 reserved[7];
>>   	/* An array of raid strides this stripe is composed of. */
>> -	struct btrfs_raid_stride strides[];
>> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
> 
> Is there a reason to use the __ underscore macro? I see no difference
> between that and DECLARE_FLEX_ARRAY and underscore usually means that
> it's special in some way.
> 

Yes, the __ version is for UAPI, like __u8 or __le32 and so on.
David Sterba June 13, 2024, 9:23 p.m. UTC | #3 
On Tue, Jun 11, 2024 at 04:33:19PM +0000, Johannes Thumshirn wrote:
> On 11.06.24 16:37, David Sterba wrote:
> > On Mon, Jun 10, 2024 at 10:40:25AM +0200, Johannes Thumshirn wrote:
> >> -#define BTRFS_STRIPE_RAID5	5
> >> -#define BTRFS_STRIPE_RAID6	6
> >> -#define BTRFS_STRIPE_RAID1C3	7
> >> -#define BTRFS_STRIPE_RAID1C4	8
> >> -
> >>   struct btrfs_stripe_extent {
> >> -	__u8 encoding;
> >> -	__u8 reserved[7];
> >>   	/* An array of raid strides this stripe is composed of. */
> >> -	struct btrfs_raid_stride strides[];
> >> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
> > 
> > Is there a reason to use the __ underscore macro? I see no difference
> > between that and DECLARE_FLEX_ARRAY and underscore usually means that
> > it's special in some way.
> > 
> 
> Yes, the __ version is for UAPI, like __u8 or __le32 and so on.

I see, though I'd rather keep the on-disk definitions free of wrappers
that hide the types. We use the __ int types but that's all and quite
clear what it means.

There already are flexible members (btrfs_leaf, btrfs_node,
btrfs_inode_extref), using the empty[] syntax. The macro wraps the
distinction that c++ needs but so far the existing declarations have't
been problematic.  So I'd rather keep the declarations consistent.
Johannes Thumshirn June 14, 2024, 9:36 a.m. UTC | #4 
On 13.06.24 23:23, David Sterba wrote:
> On Tue, Jun 11, 2024 at 04:33:19PM +0000, Johannes Thumshirn wrote:
>> On 11.06.24 16:37, David Sterba wrote:
>>> On Mon, Jun 10, 2024 at 10:40:25AM +0200, Johannes Thumshirn wrote:
>>>> -#define BTRFS_STRIPE_RAID5	5
>>>> -#define BTRFS_STRIPE_RAID6	6
>>>> -#define BTRFS_STRIPE_RAID1C3	7
>>>> -#define BTRFS_STRIPE_RAID1C4	8
>>>> -
>>>>    struct btrfs_stripe_extent {
>>>> -	__u8 encoding;
>>>> -	__u8 reserved[7];
>>>>    	/* An array of raid strides this stripe is composed of. */
>>>> -	struct btrfs_raid_stride strides[];
>>>> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
>>>
>>> Is there a reason to use the __ underscore macro? I see no difference
>>> between that and DECLARE_FLEX_ARRAY and underscore usually means that
>>> it's special in some way.
>>>
>>
>> Yes, the __ version is for UAPI, like __u8 or __le32 and so on.
> 
> I see, though I'd rather keep the on-disk definitions free of wrappers
> that hide the types. We use the __ int types but that's all and quite
> clear what it means.
> 
> There already are flexible members (btrfs_leaf, btrfs_node,
> btrfs_inode_extref), using the empty[] syntax. The macro wraps the
> distinction that c++ needs but so far the existing declarations have't
> been problematic.  So I'd rather keep the declarations consistent.
> 

Yes but all these examples have other members as well. After this patch, 
btrfs_stripe_extent is a container for btrfs_raid_stride, and C doesn't 
allow a flexmember only struct:

In file included from fs/btrfs/ctree.h:18,
                  from fs/btrfs/delayed-inode.h:19,
                  from fs/btrfs/super.c:32:
./include/uapi/linux/btrfs_tree.h:753:34: error: flexible array member 
in a struct with no named members
   753 |         struct btrfs_raid_stride strides[];
       |                                  ^~~~~~~
David Sterba June 16, 2024, 6:19 p.m. UTC | #5 
On Fri, Jun 14, 2024 at 09:36:34AM +0000, Johannes Thumshirn wrote:
> On 13.06.24 23:23, David Sterba wrote:
> > On Tue, Jun 11, 2024 at 04:33:19PM +0000, Johannes Thumshirn wrote:
> >> On 11.06.24 16:37, David Sterba wrote:
> >>> On Mon, Jun 10, 2024 at 10:40:25AM +0200, Johannes Thumshirn wrote:
> >>>> -#define BTRFS_STRIPE_RAID5	5
> >>>> -#define BTRFS_STRIPE_RAID6	6
> >>>> -#define BTRFS_STRIPE_RAID1C3	7
> >>>> -#define BTRFS_STRIPE_RAID1C4	8
> >>>> -
> >>>>    struct btrfs_stripe_extent {
> >>>> -	__u8 encoding;
> >>>> -	__u8 reserved[7];
> >>>>    	/* An array of raid strides this stripe is composed of. */
> >>>> -	struct btrfs_raid_stride strides[];
> >>>> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
> >>>
> >>> Is there a reason to use the __ underscore macro? I see no difference
> >>> between that and DECLARE_FLEX_ARRAY and underscore usually means that
> >>> it's special in some way.
> >>>
> >>
> >> Yes, the __ version is for UAPI, like __u8 or __le32 and so on.
> > 
> > I see, though I'd rather keep the on-disk definitions free of wrappers
> > that hide the types. We use the __ int types but that's all and quite
> > clear what it means.
> > 
> > There already are flexible members (btrfs_leaf, btrfs_node,
> > btrfs_inode_extref), using the empty[] syntax. The macro wraps the
> > distinction that c++ needs but so far the existing declarations have't
> > been problematic.  So I'd rather keep the declarations consistent.
> > 
> 
> Yes but all these examples have other members as well. After this patch, 
> btrfs_stripe_extent is a container for btrfs_raid_stride, and C doesn't 
> allow a flexmember only struct:
> 
> In file included from fs/btrfs/ctree.h:18,
>                   from fs/btrfs/delayed-inode.h:19,
>                   from fs/btrfs/super.c:32:
> ./include/uapi/linux/btrfs_tree.h:753:34: error: flexible array member 
> in a struct with no named members
>    753 |         struct btrfs_raid_stride strides[];
>        |                                  ^~~~~~~

To fix that __DECLARE_FLEX_ARRAY adds the layer of an anonymous struct
and an empty other member. We'd have to duplicate that so let's use the
macro.
Qu Wenruo June 17, 2024, 6:27 a.m. UTC | #6 
在 2024/6/10 18:10, Johannes Thumshirn 写道:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> Remove the encoding field from 'struct btrfs_stripe_extent'. It was
> originally intended to encode the RAID type as well as if we're a data
> or a parity stripe.
>
> But the RAID type can be inferred form the block-group and the data vs.
> parity differentiation can be done easier with adding a new key type
> for parity stripes in the RAID stripe tree.

Talking about adding new key type or even new members, I'm wondering can
we also utilizing the higher 8/16/32 bits of key.offset?

Currently the RST entry uses key.offset for the length of the entry,
which is at most the length of the max zone append size.

If the vendor (WDC) is determined to go with zone size smaller than 4G
(32bits) or 256T (48bits), we definitely have 32 or 16 bits for other
usages, without expanding the entry item size.

The 4G (32bits) looks a little unreliable but 256T (48bits) is
definitely worthy considering.

Thanks,
Qu
>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---
>   fs/btrfs/accessors.h            |  3 ---
>   fs/btrfs/print-tree.c           |  5 -----
>   fs/btrfs/raid-stripe-tree.c     | 13 -------------
>   fs/btrfs/raid-stripe-tree.h     |  3 +--
>   fs/btrfs/tree-checker.c         | 19 -------------------
>   include/uapi/linux/btrfs_tree.h | 14 +-------------
>   6 files changed, 2 insertions(+), 55 deletions(-)
>
> diff --git a/fs/btrfs/accessors.h b/fs/btrfs/accessors.h
> index 6c3deaa3e878..b2eb9cde2c5d 100644
> --- a/fs/btrfs/accessors.h
> +++ b/fs/btrfs/accessors.h
> @@ -315,11 +315,8 @@ BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);
>   BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
>   BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
>
> -BTRFS_SETGET_FUNCS(stripe_extent_encoding, struct btrfs_stripe_extent, encoding, 8);
>   BTRFS_SETGET_FUNCS(raid_stride_devid, struct btrfs_raid_stride, devid, 64);
>   BTRFS_SETGET_FUNCS(raid_stride_physical, struct btrfs_raid_stride, physical, 64);
> -BTRFS_SETGET_STACK_FUNCS(stack_stripe_extent_encoding,
> -			 struct btrfs_stripe_extent, encoding, 8);
>   BTRFS_SETGET_STACK_FUNCS(stack_raid_stride_devid, struct btrfs_raid_stride, devid, 64);
>   BTRFS_SETGET_STACK_FUNCS(stack_raid_stride_physical, struct btrfs_raid_stride, physical, 64);
>
> diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
> index 7e46aa8a0444..9f1e5e11bf71 100644
> --- a/fs/btrfs/print-tree.c
> +++ b/fs/btrfs/print-tree.c
> @@ -208,11 +208,6 @@ static void print_raid_stripe_key(const struct extent_buffer *eb, u32 item_size,
>   				  struct btrfs_stripe_extent *stripe)
>   {
>   	const int num_stripes = btrfs_num_raid_stripes(item_size);
> -	const u8 encoding = btrfs_stripe_extent_encoding(eb, stripe);
> -
> -	pr_info("\t\t\tencoding: %s\n",
> -		(encoding && encoding < BTRFS_NR_RAID_TYPES) ?
> -		btrfs_raid_array[encoding].raid_name : "unknown");
>
>   	for (int i = 0; i < num_stripes; i++)
>   		pr_info("\t\t\tstride %d devid %llu physical %llu\n",
> diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c
> index 6af6b4b9a32e..e6f7a234b8f6 100644
> --- a/fs/btrfs/raid-stripe-tree.c
> +++ b/fs/btrfs/raid-stripe-tree.c
> @@ -80,7 +80,6 @@ static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
>   	struct btrfs_key stripe_key;
>   	struct btrfs_root *stripe_root = fs_info->stripe_root;
>   	const int num_stripes = btrfs_bg_type_to_factor(bioc->map_type);
> -	u8 encoding = btrfs_bg_flags_to_raid_index(bioc->map_type);
>   	struct btrfs_stripe_extent *stripe_extent;
>   	const size_t item_size = struct_size(stripe_extent, strides, num_stripes);
>   	int ret;
> @@ -94,7 +93,6 @@ static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
>
>   	trace_btrfs_insert_one_raid_extent(fs_info, bioc->logical, bioc->size,
>   					   num_stripes);
> -	btrfs_set_stack_stripe_extent_encoding(stripe_extent, encoding);
>   	for (int i = 0; i < num_stripes; i++) {
>   		u64 devid = bioc->stripes[i].dev->devid;
>   		u64 physical = bioc->stripes[i].physical;
> @@ -159,7 +157,6 @@ int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
>   	struct extent_buffer *leaf;
>   	const u64 end = logical + *length;
>   	int num_stripes;
> -	u8 encoding;
>   	u64 offset;
>   	u64 found_logical;
>   	u64 found_length;
> @@ -222,16 +219,6 @@ int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
>
>   	num_stripes = btrfs_num_raid_stripes(btrfs_item_size(leaf, slot));
>   	stripe_extent = btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
> -	encoding = btrfs_stripe_extent_encoding(leaf, stripe_extent);
> -
> -	if (encoding != btrfs_bg_flags_to_raid_index(map_type)) {
> -		ret = -EUCLEAN;
> -		btrfs_handle_fs_error(fs_info, ret,
> -				      "on-disk stripe encoding %d doesn't match RAID index %d",
> -				      encoding,
> -				      btrfs_bg_flags_to_raid_index(map_type));
> -		goto out;
> -	}
>
>   	for (int i = 0; i < num_stripes; i++) {
>   		struct btrfs_raid_stride *stride = &stripe_extent->strides[i];
> diff --git a/fs/btrfs/raid-stripe-tree.h b/fs/btrfs/raid-stripe-tree.h
> index c9c258f84903..1ac1c21aac2f 100644
> --- a/fs/btrfs/raid-stripe-tree.h
> +++ b/fs/btrfs/raid-stripe-tree.h
> @@ -48,8 +48,7 @@ static inline bool btrfs_need_stripe_tree_update(struct btrfs_fs_info *fs_info,
>
>   static inline int btrfs_num_raid_stripes(u32 item_size)
>   {
> -	return (item_size - offsetof(struct btrfs_stripe_extent, strides)) /
> -		sizeof(struct btrfs_raid_stride);
> +	return item_size / sizeof(struct btrfs_raid_stride);
>   }
>
>   #endif
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index a2c3651a3d8f..1e140f6dabc6 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -1682,9 +1682,6 @@ static int check_inode_ref(struct extent_buffer *leaf,
>   static int check_raid_stripe_extent(const struct extent_buffer *leaf,
>   				    const struct btrfs_key *key, int slot)
>   {
> -	struct btrfs_stripe_extent *stripe_extent =
> -		btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
> -
>   	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
>   		generic_err(leaf, slot,
>   "invalid key objectid for raid stripe extent, have %llu expect aligned to %u",
> @@ -1698,22 +1695,6 @@ static int check_raid_stripe_extent(const struct extent_buffer *leaf,
>   		return -EUCLEAN;
>   	}
>
> -	switch (btrfs_stripe_extent_encoding(leaf, stripe_extent)) {
> -	case BTRFS_STRIPE_RAID0:
> -	case BTRFS_STRIPE_RAID1:
> -	case BTRFS_STRIPE_DUP:
> -	case BTRFS_STRIPE_RAID10:
> -	case BTRFS_STRIPE_RAID5:
> -	case BTRFS_STRIPE_RAID6:
> -	case BTRFS_STRIPE_RAID1C3:
> -	case BTRFS_STRIPE_RAID1C4:
> -		break;
> -	default:
> -		generic_err(leaf, slot, "invalid raid stripe encoding %u",
> -			    btrfs_stripe_extent_encoding(leaf, stripe_extent));
> -		return -EUCLEAN;
> -	}
> -
>   	return 0;
>   }
>
> diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
> index d24e8e121507..cb103c76d398 100644
> --- a/include/uapi/linux/btrfs_tree.h
> +++ b/include/uapi/linux/btrfs_tree.h
> @@ -747,21 +747,9 @@ struct btrfs_raid_stride {
>   	__le64 physical;
>   } __attribute__ ((__packed__));
>
> -/* The stripe_extent::encoding, 1:1 mapping of enum btrfs_raid_types. */
> -#define BTRFS_STRIPE_RAID0	1
> -#define BTRFS_STRIPE_RAID1	2
> -#define BTRFS_STRIPE_DUP	3
> -#define BTRFS_STRIPE_RAID10	4
> -#define BTRFS_STRIPE_RAID5	5
> -#define BTRFS_STRIPE_RAID6	6
> -#define BTRFS_STRIPE_RAID1C3	7
> -#define BTRFS_STRIPE_RAID1C4	8
> -
>   struct btrfs_stripe_extent {
> -	__u8 encoding;
> -	__u8 reserved[7];
>   	/* An array of raid strides this stripe is composed of. */
> -	struct btrfs_raid_stride strides[];
> +	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
>   } __attribute__ ((__packed__));
>
>   #define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)
>
diff mbox series

Patch

diff --git a/fs/btrfs/accessors.h b/fs/btrfs/accessors.h
index 6c3deaa3e878..b2eb9cde2c5d 100644
--- a/fs/btrfs/accessors.h
+++ b/fs/btrfs/accessors.h
@@ -315,11 +315,8 @@  BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
 
-BTRFS_SETGET_FUNCS(stripe_extent_encoding, struct btrfs_stripe_extent, encoding, 8);
 BTRFS_SETGET_FUNCS(raid_stride_devid, struct btrfs_raid_stride, devid, 64);
 BTRFS_SETGET_FUNCS(raid_stride_physical, struct btrfs_raid_stride, physical, 64);
-BTRFS_SETGET_STACK_FUNCS(stack_stripe_extent_encoding,
-			 struct btrfs_stripe_extent, encoding, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_raid_stride_devid, struct btrfs_raid_stride, devid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_raid_stride_physical, struct btrfs_raid_stride, physical, 64);
 
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index 7e46aa8a0444..9f1e5e11bf71 100644
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -208,11 +208,6 @@  static void print_raid_stripe_key(const struct extent_buffer *eb, u32 item_size,
 				  struct btrfs_stripe_extent *stripe)
 {
 	const int num_stripes = btrfs_num_raid_stripes(item_size);
-	const u8 encoding = btrfs_stripe_extent_encoding(eb, stripe);
-
-	pr_info("\t\t\tencoding: %s\n",
-		(encoding && encoding < BTRFS_NR_RAID_TYPES) ?
-		btrfs_raid_array[encoding].raid_name : "unknown");
 
 	for (int i = 0; i < num_stripes; i++)
 		pr_info("\t\t\tstride %d devid %llu physical %llu\n",
diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c
index 6af6b4b9a32e..e6f7a234b8f6 100644
--- a/fs/btrfs/raid-stripe-tree.c
+++ b/fs/btrfs/raid-stripe-tree.c
@@ -80,7 +80,6 @@  static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_key stripe_key;
 	struct btrfs_root *stripe_root = fs_info->stripe_root;
 	const int num_stripes = btrfs_bg_type_to_factor(bioc->map_type);
-	u8 encoding = btrfs_bg_flags_to_raid_index(bioc->map_type);
 	struct btrfs_stripe_extent *stripe_extent;
 	const size_t item_size = struct_size(stripe_extent, strides, num_stripes);
 	int ret;
@@ -94,7 +93,6 @@  static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 
 	trace_btrfs_insert_one_raid_extent(fs_info, bioc->logical, bioc->size,
 					   num_stripes);
-	btrfs_set_stack_stripe_extent_encoding(stripe_extent, encoding);
 	for (int i = 0; i < num_stripes; i++) {
 		u64 devid = bioc->stripes[i].dev->devid;
 		u64 physical = bioc->stripes[i].physical;
@@ -159,7 +157,6 @@  int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
 	struct extent_buffer *leaf;
 	const u64 end = logical + *length;
 	int num_stripes;
-	u8 encoding;
 	u64 offset;
 	u64 found_logical;
 	u64 found_length;
@@ -222,16 +219,6 @@  int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
 
 	num_stripes = btrfs_num_raid_stripes(btrfs_item_size(leaf, slot));
 	stripe_extent = btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
-	encoding = btrfs_stripe_extent_encoding(leaf, stripe_extent);
-
-	if (encoding != btrfs_bg_flags_to_raid_index(map_type)) {
-		ret = -EUCLEAN;
-		btrfs_handle_fs_error(fs_info, ret,
-				      "on-disk stripe encoding %d doesn't match RAID index %d",
-				      encoding,
-				      btrfs_bg_flags_to_raid_index(map_type));
-		goto out;
-	}
 
 	for (int i = 0; i < num_stripes; i++) {
 		struct btrfs_raid_stride *stride = &stripe_extent->strides[i];
diff --git a/fs/btrfs/raid-stripe-tree.h b/fs/btrfs/raid-stripe-tree.h
index c9c258f84903..1ac1c21aac2f 100644
--- a/fs/btrfs/raid-stripe-tree.h
+++ b/fs/btrfs/raid-stripe-tree.h
@@ -48,8 +48,7 @@  static inline bool btrfs_need_stripe_tree_update(struct btrfs_fs_info *fs_info,
 
 static inline int btrfs_num_raid_stripes(u32 item_size)
 {
-	return (item_size - offsetof(struct btrfs_stripe_extent, strides)) /
-		sizeof(struct btrfs_raid_stride);
+	return item_size / sizeof(struct btrfs_raid_stride);
 }
 
 #endif
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index a2c3651a3d8f..1e140f6dabc6 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -1682,9 +1682,6 @@  static int check_inode_ref(struct extent_buffer *leaf,
 static int check_raid_stripe_extent(const struct extent_buffer *leaf,
 				    const struct btrfs_key *key, int slot)
 {
-	struct btrfs_stripe_extent *stripe_extent =
-		btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
-
 	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
 		generic_err(leaf, slot,
 "invalid key objectid for raid stripe extent, have %llu expect aligned to %u",
@@ -1698,22 +1695,6 @@  static int check_raid_stripe_extent(const struct extent_buffer *leaf,
 		return -EUCLEAN;
 	}
 
-	switch (btrfs_stripe_extent_encoding(leaf, stripe_extent)) {
-	case BTRFS_STRIPE_RAID0:
-	case BTRFS_STRIPE_RAID1:
-	case BTRFS_STRIPE_DUP:
-	case BTRFS_STRIPE_RAID10:
-	case BTRFS_STRIPE_RAID5:
-	case BTRFS_STRIPE_RAID6:
-	case BTRFS_STRIPE_RAID1C3:
-	case BTRFS_STRIPE_RAID1C4:
-		break;
-	default:
-		generic_err(leaf, slot, "invalid raid stripe encoding %u",
-			    btrfs_stripe_extent_encoding(leaf, stripe_extent));
-		return -EUCLEAN;
-	}
-
 	return 0;
 }
 
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index d24e8e121507..cb103c76d398 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -747,21 +747,9 @@  struct btrfs_raid_stride {
 	__le64 physical;
 } __attribute__ ((__packed__));
 
-/* The stripe_extent::encoding, 1:1 mapping of enum btrfs_raid_types. */
-#define BTRFS_STRIPE_RAID0	1
-#define BTRFS_STRIPE_RAID1	2
-#define BTRFS_STRIPE_DUP	3
-#define BTRFS_STRIPE_RAID10	4
-#define BTRFS_STRIPE_RAID5	5
-#define BTRFS_STRIPE_RAID6	6
-#define BTRFS_STRIPE_RAID1C3	7
-#define BTRFS_STRIPE_RAID1C4	8
-
 struct btrfs_stripe_extent {
-	__u8 encoding;
-	__u8 reserved[7];
 	/* An array of raid strides this stripe is composed of. */
-	struct btrfs_raid_stride strides[];
+	__DECLARE_FLEX_ARRAY(struct btrfs_raid_stride, strides);
 } __attribute__ ((__packed__));
 
 #define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)