uuid: Add inline helpers to import / export UUIDs
Subsystems (3)
Andy Shevchenko
reviewerPATCH v3 1/4 uuid: Add inline helpers to import / export UUIDs
Sometimes we may need to import UUID from or export to the raw buffer, which is provided outside of kernel and can't be declared as UUID type. With current API this operation will require an explicit casting to one of UUID types and length, that is always a constant derived as sizeof the certain UUID type.
Provide a helpful set of inline helpers to minimize developer's effort in the cases when raw buffers are involved.
--- include/linux/uuid.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
include/linux/uuid.h +20 -0
@@ -43,6 +43,16 @@ static inline void guid_copy(guid_t *dst, const guid_t *src)memcpy (dst, src,sizeof (guid_t)); } +static inline void import_guid (guid_t *dst,const __u8 *src) +{ +memcpy (dst, src,sizeof (guid_t)); +} + +static inline void export_guid (__u8 *dst,const guid_t *src) +{ +memcpy (dst, src,sizeof (guid_t)); +} +static inline bool guid_is_null (const guid_t *guid) {return guid_equal (guid, &guid_null);
@@ -58,6 +68,16 @@ static inline void uuid_copy(uuid_t *dst, const uuid_t *src)memcpy (dst, src,sizeof (uuid_t)); } +static inline void import_uuid (uuid_t *dst,const __u8 *src) +{ +memcpy (dst, src,sizeof (uuid_t)); +} + +static inline void export_uuid (__u8 *dst,const uuid_t *src) +{ +memcpy (dst, src,sizeof (uuid_t)); +} +static inline bool uuid_is_null (const uuid_t *uuid) {return uuid_equal (uuid, &uuid_null);
Signature · 1 line
2.20.1
Andy Shevchenko
reviewerPATCH v3 2/4 uuid: Provide a GUID generator for raw buffer
In some cases we would like to generate a GUID and export it. Though it would require either casting to internal kernel types or an intermediate buffer. Instead we may achieve this by supplying a pointer to raw buffer and make a complimentary API to existing one for UUIDs.
--- include/linux/uuid.h | 1 + lib/uuid.c | 10 ++++++++++ 2 files changed, 11 insertions(+)
include/linux/uuid.h +1 -0
@@ -84,6 +84,7 @@ static inline bool uuid_is_null(const uuid_t *uuid) }void generate_random_uuid (unsigned char uuid[16 ]); +void generate_random_guid (unsigned char guid[16 ]);extern void guid_gen (guid_t *u);extern void uuid_gen (uuid_t *u);
lib/uuid.c +10 -0
@@ -40,6 +40,16 @@ void generate_random_uuid(unsigned char uuid[16]) }EXPORT_SYMBOL (generate_random_uuid); +void generate_random_guid (unsigned char guid[16 ]) +{ +get_random_bytes (guid,16 ); +/* Set GUID version to 4 --- truly random generation */ + guid[7 ] = (guid[7 ] &0x0F ) |0x40 ; +/* Set the GUID variant to DCE */ + guid[8 ] = (guid[8 ] &0x3F ) |0x80 ; +} +EXPORT_SYMBOL (generate_random_guid); +static void __uuid_gen_common (__u8 b[16 ]) {prandom_bytes (b,16 );
Signature · 1 line
2.20.1
Andy Shevchenko
reviewerPATCH v3 3/4 Btrfs: Switch to use new generic UUID API
In reply to Andy ShevchenkoThere are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do the conversion here.
--- fs/btrfs/disk-io.c | 6 +++--- fs/btrfs/ioctl.c | 4 +--- fs/btrfs/root-tree.c | 4 +--- fs/btrfs/transaction.c | 7 +++---- 4 files changed, 8 insertions(+), 13 deletions(-)
fs/btrfs/disk-io.c +3 -3
@@ -1259,7 +1259,6 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,struct btrfs_key key;unsigned int nofs_flag;int ret =0 ; -uuid_le uuid =NULL_UUID_LE ;/* * We're holding a transaction handle, so use a NOFS memory allocation
@@ -1299,8 +1298,9 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,btrfs_set_root_last_snapshot (&root->root_item,0 );btrfs_set_root_dirid (&root->root_item,0 );if (is_fstree (objectid)) -uuid_le_gen (&uuid); -memcpy (root->root_item.uuid, uuid.b,BTRFS_UUID_SIZE ); +generate_random_guid (root->root_item.uuid); +else +export_guid (root->root_item.uuid, &guid_null); root->root_item.drop_level =0 ; key.objectid = objectid;
fs/btrfs/ioctl.c +1 -3
@@ -573,7 +573,6 @@ static noinline int create_subvol(struct inode *dir,u64 objectid;u64 new_dirid =BTRFS_FIRST_FREE_OBJECTID ;u64 index =0 ; -uuid_le new_uuid; root_item =kzalloc (sizeof (*root_item),GFP_KERNEL );if (!root_item)
@@ -643,8 +642,7 @@ static noinline int create_subvol(struct inode *dir,btrfs_set_root_generation_v2 (root_item,btrfs_root_generation (root_item)); -uuid_le_gen (&new_uuid); -memcpy (root_item->uuid, new_uuid.b,BTRFS_UUID_SIZE ); +generate_random_guid (root_item->uuid);btrfs_set_stack_timespec_sec (&root_item->otime, cur_time.tv_sec);btrfs_set_stack_timespec_nsec (&root_item->otime, cur_time.tv_nsec); root_item->ctime = root_item->otime;
fs/btrfs/root-tree.c +1 -3
@@ -22,7 +22,6 @@static void btrfs_read_root_item (struct extent_buffer *eb,int slot,struct btrfs_root_item *item) { -uuid_le uuid;u32 len;int need_reset =0 ;
@@ -44,8 +43,7 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot,sizeof (*item) - offsetof(struct btrfs_root_item , generation_v2)); -uuid_le_gen (&uuid); -memcpy (item->uuid, uuid.b,BTRFS_UUID_SIZE ); +generate_random_guid (item->uuid); } }
fs/btrfs/transaction.c +3 -4
@@ -1395,7 +1395,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,u64 index =0 ;u64 objectid;u64 root_flags; -uuid_le new_uuid;ASSERT (pending->path); path = pending->path;
@@ -1488,8 +1487,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,btrfs_set_root_generation_v2 (new_root_item, trans->transid); -uuid_le_gen (&new_uuid); -memcpy (new_root_item->uuid, new_uuid.b,BTRFS_UUID_SIZE ); +generate_random_guid (new_root_item->uuid);memcpy (new_root_item->parent_uuid, root->root_item.uuid,BTRFS_UUID_SIZE );if (!(root_flags &BTRFS_ROOT_SUBVOL_RDONLY )) {
@@ -1600,7 +1598,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,btrfs_abort_transaction (trans, ret); goto fail; } - ret =btrfs_uuid_tree_add (trans, new_uuid.b,BTRFS_UUID_KEY_SUBVOL , + ret =btrfs_uuid_tree_add (trans, new_root_item->uuid, +BTRFS_UUID_KEY_SUBVOL , objectid);if (ret) {btrfs_abort_transaction (trans, ret);
Signature · 1 line
2.20.1
Re: [PATCH v3 3/4] Btrfs: Switch to use new generic UUID API
Quoted 4 lines · Andy Shevchenko
There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do the conversion here.
Why? What was broken in the old versions? What benefit do we have apart from unneeded churn?
Thanks,
Johannes
Signature · 6 lines
Johannes Thumshirn SUSE Labs Filesystems [email protected] +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
Andy Shevchenko
reviewerRe: [PATCH v3 3/4] Btrfs: Switch to use new generic UUID API
Quoted 8 lines · Johannes Thumshirn
Quoted 4 lines · Andy Shevchenko
There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do the conversion here.
Why? What was broken in the old versions? What benefit do we have apart from unneeded churn?
I think Christoph can explain this better than me.
By the way, if you look to the headers, there is no more "old" API, it's covered as alias to the new one.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Re: [PATCH v3 3/4] Btrfs: Switch to use new generic UUID API
Quoted 7 lines · Andy Shevchenko
Quoted 6 lines · Johannes Thumshirn
Quoted 4 lines · Andy Shevchenko
There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do the conversion here.
Quoted 7 lines
Quoted 2 lines
Why? What was broken in the old versions? What benefit do we have apart from unneeded churn?
I think Christoph can explain this better than me.
By the way, if you look to the headers, there is no more "old" API, it's covered as alias to the new one.
AFAIU it's mostly the naming that causes problems here as a little endian UUID doesn't really exits, is called GUID.
But please at least document this in a cover letter. Also what tests did you make? I know most of these functions have their origin in XFS.
Thanks,
Johannes
Signature · 6 lines
Johannes Thumshirn SUSE Labs Filesystems [email protected] +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
Andy Shevchenko
reviewerRe: [PATCH v3 3/4] Btrfs: Switch to use new generic UUID API
Quoted 11 lines · Johannes Thumshirn
Quoted 10 lines · Andy Shevchenko
Quoted 8 lines · Johannes Thumshirn
Quoted 4 lines · Andy Shevchenko
There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do the conversion here.
Why? What was broken in the old versions? What benefit do we have apart from unneeded churn?
Quoted 7 lines
Quoted 4 lines
I think Christoph can explain this better than me.
By the way, if you look to the headers, there is no more "old" API, it's covered as alias to the new one.
AFAIU it's mostly the naming that causes problems here as a little endian UUID doesn't really exits, is called GUID.
Yes, that's the main point for now.
Quoted 2 lines
But please at least document this in a cover letter. Also what tests did you make? I know most of these functions have their origin in XFS.
I did only compile test.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Andy Shevchenko
reviewerPATCH v3 4/4 uuid: Remove no more needed macro
In reply to Andy Shevchenkouuid_le_gen() is no used anymore, remove it for good.
--- include/linux/uuid.h | 1 - 1 file changed, 1 deletion(-)
include/linux/uuid.h +0 -1
@@ -98,7 +98,6 @@ int guid_parse(const char *uuid, guid_t *u);int uuid_parse (const char *uuid,uuid_t *u);/* backwards compatibility, don't use in new code */ -#define uuid_le_gen (u) guid_gen(u)#define uuid_le_to_bin (guid, u) guid_parse(guid, u)static inline int uuid_le_cmp (const guid_t u1,const guid_t u2)
Signature · 1 line
2.20.1