cleanup UUID types

cleanup UUID types

[Christoph Hellwig]

Hi all,

this series, which is a combined effort from Amir, Andy and me introduces
new uuid_t and guid_t type names that are less confusing than the existing
types, adds new helpers for them and starts switching the fs code over to
it.  Andy has additional patches on top to convert many of the users
that use char arrays for UUIDs and GUIDs to these (or rather a predecessor
for now until updated).

[PATCH 01/16] xfs: use uuid_copy() helper to abstract uuid_t

[Christoph Hellwig]

From: Amir Goldstein <amir73il@gmail.com>

uuid_t definition is about to change.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_inode_item.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 08cb7d1a4a3a..013cc78d7daf 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -834,9 +834,7 @@ xfs_inode_item_format_convert(
 		in_f->ilf_dsize = in_f32->ilf_dsize;
 		in_f->ilf_ino = in_f32->ilf_ino;
 		/* copy biggest field of ilf_u */
-		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
-		       in_f32->ilf_u.ilfu_uuid.__u_bits,
-		       sizeof(uuid_t));
+		uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f32->ilf_u.ilfu_uuid);
 		in_f->ilf_blkno = in_f32->ilf_blkno;
 		in_f->ilf_len = in_f32->ilf_len;
 		in_f->ilf_boffset = in_f32->ilf_boffset;
@@ -851,9 +849,7 @@ xfs_inode_item_format_convert(
 		in_f->ilf_dsize = in_f64->ilf_dsize;
 		in_f->ilf_ino = in_f64->ilf_ino;
 		/* copy biggest field of ilf_u */
-		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
-		       in_f64->ilf_u.ilfu_uuid.__u_bits,
-		       sizeof(uuid_t));
+		uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f64->ilf_u.ilfu_uuid);
 		in_f->ilf_blkno = in_f64->ilf_blkno;
 		in_f->ilf_len = in_f64->ilf_len;
 		in_f->ilf_boffset = in_f64->ilf_boffset;
-- 
2.11.0

[PATCH 02/16] xfs: use uuid_be to implement the uuid_t type

[Christoph Hellwig]

Use the generic Linux definition to implement our UUID type, this will
allow using more generic infrastructure in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/uuid.h      | 4 ----
 fs/xfs/xfs_linux.h | 3 +++
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/uuid.h b/fs/xfs/uuid.h
index 104db0f3bed6..4f1441ba4fa5 100644
--- a/fs/xfs/uuid.h
+++ b/fs/xfs/uuid.h
@@ -18,10 +18,6 @@
 #ifndef __XFS_SUPPORT_UUID_H__
 #define __XFS_SUPPORT_UUID_H__
 
-typedef struct {
-	unsigned char	__u_bits[16];
-} uuid_t;
-
 extern int uuid_is_nil(uuid_t *uuid);
 extern int uuid_equal(uuid_t *uuid1, uuid_t *uuid2);
 extern void uuid_getnodeuniq(uuid_t *uuid, int fsid [2]);
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 044fb0e15390..89ee5ec66837 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -19,6 +19,7 @@
 #define __XFS_LINUX__
 
 #include <linux/types.h>
+#include <linux/uuid.h>
 
 /*
  * Kernel specific type declarations for XFS
@@ -38,6 +39,8 @@ typedef __s64			xfs_daddr_t;	/* <disk address> type */
 typedef __u32			xfs_dev_t;
 typedef __u32			xfs_nlink_t;
 
+typedef uuid_be			uuid_t;
+
 #include "xfs_types.h"
 
 #include "kmem.h"
-- 
2.11.0

[PATCH 03/16] uuid: rename uuid types

[Christoph Hellwig]

Our "little endian" UUID really is a Wintel GUID, so rename it and its
helpers such (guid_t).  The big endian UUID is the only true one, so
give it the name uuid_t.  The uuid_le and uuid_be names are retained for,
but will hopefully go away soon.

Also remove the existing typedef in XFS that's now been superceeded by
the generic type name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[andy: also updated the UUID_LE/UUID_BE macros including fallout]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 fs/jfs/jfs_logmgr.h       |  4 ++--
 fs/xfs/xfs_linux.h        |  2 --
 include/linux/efi.h       |  3 +--
 include/linux/uuid.h      | 28 ++++++++++++++++++----------
 include/uapi/linux/uuid.h | 27 +++++++++++++++------------
 lib/test_uuid.c           | 12 ++++++------
 lib/uuid.c                | 28 ++++++++++++++--------------
 lib/vsprintf.c            |  4 ++--
 8 files changed, 58 insertions(+), 50 deletions(-)

diff --git a/fs/jfs/jfs_logmgr.h b/fs/jfs/jfs_logmgr.h
index e38c21598850..0b9efddeb9f5 100644
--- a/fs/jfs/jfs_logmgr.h
+++ b/fs/jfs/jfs_logmgr.h
@@ -19,6 +19,8 @@
 #ifndef	_H_JFS_LOGMGR
 #define _H_JFS_LOGMGR
 
+#include <linux/uuid.h>
+
 #include "jfs_filsys.h"
 #include "jfs_lock.h"
 
@@ -80,8 +82,6 @@ struct logsuper {
 	} active[MAX_ACTIVE];	/* 2048: active file systems list */
 };
 
-#define NULL_UUID "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
-
 /* log flag: commit option (see jfs_filsys.h) */
 
 /* log state */
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 89ee5ec66837..2c33d915e550 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -39,8 +39,6 @@ typedef __s64			xfs_daddr_t;	/* <disk address> type */
 typedef __u32			xfs_dev_t;
 typedef __u32			xfs_nlink_t;
 
-typedef uuid_be			uuid_t;
-
 #include "xfs_types.h"
 
 #include "kmem.h"
diff --git a/include/linux/efi.h b/include/linux/efi.h
index ec36f42a2add..cbd4d00e62c5 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -50,7 +50,7 @@ typedef void *efi_handle_t;
 typedef uuid_le efi_guid_t;
 
 #define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \
-	UUID_LE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
+	GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
 
 /*
  * Generic EFI table header
@@ -584,7 +584,6 @@ void efi_native_runtime_setup(void);
  * Note that the 'extra space' separates the values at the same place
  * where the UEFI SPEC breaks the line.
  */
-#define NULL_GUID				EFI_GUID(0x00000000, 0x0000, 0x0000,  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
 #define MPS_TABLE_GUID				EFI_GUID(0xeb9d2d2f, 0x2d88, 0x11d3,  0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define ACPI_TABLE_GUID				EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3,  0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define ACPI_20_TABLE_GUID			EFI_GUID(0x8868e871, 0xe4f1, 0x11d3,  0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81)
diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index 4dff73a89758..af669f317780 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -48,27 +48,35 @@ struct uuid_v1 {
  */
 #define	UUID_STRING_LEN		36
 
-static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2)
+static inline int guid_cmp(const guid_t u1, const guid_t u2)
 {
-	return memcmp(&u1, &u2, sizeof(uuid_le));
+	return memcmp(&u1, &u2, sizeof(guid_t));
 }
 
-static inline int uuid_be_cmp(const uuid_be u1, const uuid_be u2)
+static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
 {
-	return memcmp(&u1, &u2, sizeof(uuid_be));
+	return memcmp(&u1, &u2, sizeof(uuid_t));
 }
 
 void generate_random_uuid(unsigned char uuid[16]);
 
-extern void uuid_le_gen(uuid_le *u);
-extern void uuid_be_gen(uuid_be *u);
+extern void guid_gen(guid_t *u);
+extern void uuid_gen(uuid_t *u);
 
 bool __must_check uuid_is_valid(const char *uuid);
 
-extern const u8 uuid_le_index[16];
-extern const u8 uuid_be_index[16];
+extern const u8 guid_index[16];
+extern const u8 uuid_index[16];
 
-int uuid_le_to_bin(const char *uuid, uuid_le *u);
-int uuid_be_to_bin(const char *uuid, uuid_be *u);
+int guid_to_bin(const char *uuid, guid_t *u);
+int uuid_to_bin(const char *uuid, uuid_t *u);
+
+/* backwards compatibility, don't use in new code */
+#define uuid_le_cmp(u1, u2)	guid_cmp(u1, u2)
+#define uuid_be_cmp(u1, u2)	uuid_cmp(u1, u2)
+#define uuid_le_gen(u)		guid_gen(u)
+#define uuid_be_gen(u)		uuid_gen(u)
+#define uuid_le_to_bin(guid, u)	guid_to_bin(guid, u)
+#define uuid_be_to_bin(uuid, u)	uuid_to_bin(uuid, u)
 
 #endif
diff --git a/include/uapi/linux/uuid.h b/include/uapi/linux/uuid.h
index 3738e5fb6a4d..1a2914d8b225 100644
--- a/include/uapi/linux/uuid.h
+++ b/include/uapi/linux/uuid.h
@@ -22,33 +22,36 @@
 
 typedef struct {
 	__u8 b[16];
-} uuid_le;
+} guid_t;
 
 typedef struct {
 	__u8 b[16];
-} uuid_be;
+} uuid_t;
 
-#define UUID_LE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)		\
-((uuid_le)								\
+#define GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)			\
+((guid_t)								\
 {{ (a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff, \
    (b) & 0xff, ((b) >> 8) & 0xff,					\
    (c) & 0xff, ((c) >> 8) & 0xff,					\
    (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }})
 
-#define UUID_BE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)		\
-((uuid_be)								\
+#define UUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)			\
+((uuid_t)								\
 {{ ((a) >> 24) & 0xff, ((a) >> 16) & 0xff, ((a) >> 8) & 0xff, (a) & 0xff, \
    ((b) >> 8) & 0xff, (b) & 0xff,					\
    ((c) >> 8) & 0xff, (c) & 0xff,					\
    (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }})
 
-#define NULL_UUID_LE							\
-	UUID_LE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
-		0x00, 0x00, 0x00, 0x00)
+#define NULL_GUID							\
+	GUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
+	     0x00, 0x00, 0x00, 0x00)
 
-#define NULL_UUID_BE							\
-	UUID_BE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
-		0x00, 0x00, 0x00, 0x00)
+#define NULL_UUID							\
+	UUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
+	     0x00, 0x00, 0x00, 0x00)
 
+/* backwards compatibility, don't use in new code */
+typedef guid_t uuid_le;
+typedef uuid_t uuid_be;
 
 #endif /* _UAPI_LINUX_UUID_H_ */
diff --git a/lib/test_uuid.c b/lib/test_uuid.c
index 547d3127a3cf..7e05c1565dcc 100644
--- a/lib/test_uuid.c
+++ b/lib/test_uuid.c
@@ -18,18 +18,18 @@ struct test_uuid_data {
 static const struct test_uuid_data test_uuid_test_data[] = {
 	{
 		.uuid = "c33f4995-3701-450e-9fbf-206a2e98e576",
-		.le = UUID_LE(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
-		.be = UUID_BE(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
+		.le = GUID(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
+		.be = UUID(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
 	},
 	{
 		.uuid = "64b4371c-77c1-48f9-8221-29f054fc023b",
-		.le = UUID_LE(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
-		.be = UUID_BE(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
+		.le = GUID(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
+		.be = UUID(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
 	},
 	{
 		.uuid = "0cb4ddff-a545-4401-9d06-688af53e7f84",
-		.le = UUID_LE(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
-		.be = UUID_BE(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
+		.le = GUID(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
+		.be = UUID(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
 	},
 };
 
diff --git a/lib/uuid.c b/lib/uuid.c
index 37687af77ff8..f80dc63f6ca8 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -21,10 +21,10 @@
 #include <linux/uuid.h>
 #include <linux/random.h>
 
-const u8 uuid_le_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
-EXPORT_SYMBOL(uuid_le_index);
-const u8 uuid_be_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
-EXPORT_SYMBOL(uuid_be_index);
+const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
+EXPORT_SYMBOL(guid_index);
+const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
+EXPORT_SYMBOL(uuid_index);
 
 /***************************************************************
  * Random UUID interface
@@ -53,21 +53,21 @@ static void __uuid_gen_common(__u8 b[16])
 	b[8] = (b[8] & 0x3F) | 0x80;
 }
 
-void uuid_le_gen(uuid_le *lu)
+void guid_gen(guid_t *lu)
 {
 	__uuid_gen_common(lu->b);
 	/* version 4 : random generation */
 	lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
 }
-EXPORT_SYMBOL_GPL(uuid_le_gen);
+EXPORT_SYMBOL_GPL(guid_gen);
 
-void uuid_be_gen(uuid_be *bu)
+void uuid_gen(uuid_t *bu)
 {
 	__uuid_gen_common(bu->b);
 	/* version 4 : random generation */
 	bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
 }
-EXPORT_SYMBOL_GPL(uuid_be_gen);
+EXPORT_SYMBOL_GPL(uuid_gen);
 
 /**
   * uuid_is_valid - checks if UUID string valid
@@ -115,14 +115,14 @@ static int __uuid_to_bin(const char *uuid, __u8 b[16], const u8 ei[16])
 	return 0;
 }
 
-int uuid_le_to_bin(const char *uuid, uuid_le *u)
+int guid_to_bin(const char *uuid, guid_t *u)
 {
-	return __uuid_to_bin(uuid, u->b, uuid_le_index);
+	return __uuid_to_bin(uuid, u->b, guid_index);
 }
-EXPORT_SYMBOL(uuid_le_to_bin);
+EXPORT_SYMBOL(guid_to_bin);
 
-int uuid_be_to_bin(const char *uuid, uuid_be *u)
+int uuid_to_bin(const char *uuid, uuid_t *u)
 {
-	return __uuid_to_bin(uuid, u->b, uuid_be_index);
+	return __uuid_to_bin(uuid, u->b, uuid_index);
 }
-EXPORT_SYMBOL(uuid_be_to_bin);
+EXPORT_SYMBOL(uuid_to_bin);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 2d41de3f98a1..9f37d6208e99 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1308,14 +1308,14 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
 	char uuid[UUID_STRING_LEN + 1];
 	char *p = uuid;
 	int i;
-	const u8 *index = uuid_be_index;
+	const u8 *index = uuid_index;
 	bool uc = false;
 
 	switch (*(++fmt)) {
 	case 'L':
 		uc = true;		/* fall-through */
 	case 'l':
-		index = uuid_le_index;
+		index = guid_index;
 		break;
 	case 'B':
 		uc = true;
-- 
2.11.0

Re: [PATCH 03/16] uuid: rename uuid types

[Amir Goldstein]

On Wed, May 10, 2017 at 9:02 PM, Christoph Hellwig <hch@lst.de> wrote:
> Our "little endian" UUID really is a Wintel GUID, so rename it and its
> helpers such (guid_t).  The big endian UUID is the only true one, so
> give it the name uuid_t.  The uuid_le and uuid_be names are retained for,
> but will hopefully go away soon.
>
> Also remove the existing typedef in XFS that's now been superceeded by
> the generic type name.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> [andy: also updated the UUID_LE/UUID_BE macros including fallout]
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
[...]

>
> -static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2)
> +static inline int guid_cmp(const guid_t u1, const guid_t u2)
>  {
> -       return memcmp(&u1, &u2, sizeof(uuid_le));
> +       return memcmp(&u1, &u2, sizeof(guid_t));
>  }
>
> -static inline int uuid_be_cmp(const uuid_be u1, const uuid_be u2)
> +static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
>  {
> -       return memcmp(&u1, &u2, sizeof(uuid_be));
> +       return memcmp(&u1, &u2, sizeof(uuid_t));
>  }
>


I think we should use this opportunity to change these to (uuid_t *, uuid_t *)
which is more in line with the rest of the helpers including the new helpers
hoisted from xfs.

[...]

> +/* backwards compatibility, don't use in new code */
> +#define uuid_le_cmp(u1, u2)    guid_cmp(u1, u2)
> +#define uuid_be_cmp(u1, u2)    uuid_cmp(u1, u2)

Therefore:
#define uuid_le_cmp(u1, u2)    guid_cmp(&(u1), &(u2))
#define uuid_be_cmp(u1, u2)    uuid_cmp(&(u1), &(u2))

Re: [PATCH 03/16] uuid: rename uuid types

[Christoph Hellwig]

On Wed, May 10, 2017 at 10:15:51PM +0300, Amir Goldstein wrote:
> > +static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
> >  {
> > -       return memcmp(&u1, &u2, sizeof(uuid_be));
> > +       return memcmp(&u1, &u2, sizeof(uuid_t));
> >  }
> >
> 
> 
> I think we should use this opportunity to change these to (uuid_t *, uuid_t *)
> which is more in line with the rest of the helpers including the new helpers
> hoisted from xfs.

Or just kill them off - uuid/guid_equals is the better interface for all
existing users as far as I can tell.  My updated series already kills
off the be/uuid one, the le/guid one will need a bit more work, though.

Re: [PATCH 03/16] uuid: rename uuid types

[Amir Goldstein]

On Thu, May 11, 2017 at 10:59 AM, Christoph Hellwig <hch@lst.de> wrote:
> On Wed, May 10, 2017 at 10:15:51PM +0300, Amir Goldstein wrote:
>> > +static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
>> >  {
>> > -       return memcmp(&u1, &u2, sizeof(uuid_be));
>> > +       return memcmp(&u1, &u2, sizeof(uuid_t));
>> >  }
>> >
>>
>>
>> I think we should use this opportunity to change these to (uuid_t *, uuid_t *)
>> which is more in line with the rest of the helpers including the new helpers
>> hoisted from xfs.
>
> Or just kill them off - uuid/guid_equals is the better interface for all
> existing users as far as I can tell.  My updated series already kills
> off the be/uuid one, the le/guid one will need a bit more work, though.

That works too. and for another argument, why need a helper uuid/guid_cmp
when one can use C comparison (i.e. u1 != u2) ? assuming that we have no
reason to abstract that fact that uuid_t/guid_t are a struct type.

[PATCH 04/16] uuid: don't export guid_index and uuid_index

[Christoph Hellwig]

These are only used in uuid.c and vsprintf.c and aren't something modules
should use directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/uuid.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/lib/uuid.c b/lib/uuid.c
index f80dc63f6ca8..003bf6823003 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -22,9 +22,7 @@
 #include <linux/random.h>
 
 const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
-EXPORT_SYMBOL(guid_index);
 const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
-EXPORT_SYMBOL(uuid_index);
 
 /***************************************************************
  * Random UUID interface
-- 
2.11.0

[PATCH 05/16] uuid: add the v1 layout to uuid_t

[Christoph Hellwig]

Turn the content of uuid_t into a union and add the fields for the v1
interpretation to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/uapi/linux/uuid.h | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/uuid.h b/include/uapi/linux/uuid.h
index 1a2914d8b225..1039d2f3e114 100644
--- a/include/uapi/linux/uuid.h
+++ b/include/uapi/linux/uuid.h
@@ -25,7 +25,34 @@ typedef struct {
 } guid_t;
 
 typedef struct {
-	__u8 b[16];
+	union {
+		__u8			b[16];
+
+		/*
+		 * V1 (time-based) UUID definition [RFC 4122]:
+		 * - the timestamp is a 60-bit value, split 32/16/12, and goes
+		 *   in 100ns increments since midnight 15th October 1582
+		 *   - add UUID_TO_UNIX_TIME to convert unix time in 100ns
+		 *     units to UUID time
+		 * - the clock sequence is a 14-bit counter to avoid duplicate
+		 *   times
+		 */
+		struct {
+			__be32		time_low;
+			__be16		time_mid;
+			__be16		time_hi_and_version;
+#define UUID_TO_UNIX_TIME	0x01b21dd213814000ULL
+#define UUID_TIMEHI_MASK	0x0fff
+#define UUID_VERSION_TIME	0x1000	/* time-based UUID */
+#define UUID_VERSION_NAME	0x3000	/* name-based UUID */
+#define UUID_VERSION_RANDOM	0x4000	/* (pseudo-)random generated UUID */
+			u8		clock_seq_hi_and_reserved;
+#define UUID_CLOCKHI_MASK	0x3f
+#define UUID_VARIANT_STD	0x80
+			u8		clock_seq_low;
+			u8		node[6];
+		} v1;
+	};
 } uuid_t;
 
 #define GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)			\
-- 
2.11.0

Re: [PATCH 05/16] uuid: add the v1 layout to uuid_t

[Andy Shevchenko]

On Wed, 2017-05-10 at 20:02 +0200, Christoph Hellwig wrote:
> Turn the content of uuid_t into a union and add the fields for the v1
> interpretation to it.

In the branch it has fix for UUID() wrt union change, but there missed
similar for GUID().

+#define UUID(a, _b, c, d0, d1, d2, d3, d4, d5, d6,
d7)                 \
+{ .b = { \

^^^ This should be done for GUID() as well.

While here, can we indent \ to be the same as of the rest lines in
macro(s) ?

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH 05/16] uuid: add the v1 layout to uuid_t

[Christoph Hellwig]

On Thu, May 11, 2017 at 02:40:38PM +0300, Andy Shevchenko wrote:
> On Wed, 2017-05-10 at 20:02 +0200, Christoph Hellwig wrote:
> > Turn the content of uuid_t into a union and add the fields for the v1
> > interpretation to it.
> 
> In the branch it has fix for UUID() wrt union change, but there missed
> similar for GUID().

Actually UUID needed this because uuid_t has a unіon inside, GUID
should not need it because it doesn't.

> While here, can we indent \ to be the same as of the rest lines in
> macro(s) ?

Sure.

[PATCH 06/16] afs: switch to use uuid_t and uuid_gen

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/afs/cmservice.c | 46 +++++++++++++++++++++++-----------------------
 fs/afs/internal.h  |  2 +-
 fs/afs/main.c      |  4 ++--
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 3062cceb5c2a..d4e77d12570c 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -350,7 +350,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 {
 	struct sockaddr_rxrpc srx;
 	struct afs_server *server;
-	struct uuid_v1 *r;
+	uuid_t *r;
 	unsigned loop;
 	__be32 *b;
 	int ret;
@@ -380,20 +380,20 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 		}
 
 		_debug("unmarshall UUID");
-		call->request = kmalloc(sizeof(struct uuid_v1), GFP_KERNEL);
+		call->request = kmalloc(sizeof(uuid_t), GFP_KERNEL);
 		if (!call->request)
 			return -ENOMEM;
 
 		b = call->buffer;
 		r = call->request;
-		r->time_low			= b[0];
-		r->time_mid			= htons(ntohl(b[1]));
-		r->time_hi_and_version		= htons(ntohl(b[2]));
-		r->clock_seq_hi_and_reserved 	= ntohl(b[3]);
-		r->clock_seq_low		= ntohl(b[4]);
+		r->v1.time_low			= b[0];
+		r->v1.time_mid			= htons(ntohl(b[1]));
+		r->v1.time_hi_and_version	= htons(ntohl(b[2]));
+		r->v1.clock_seq_hi_and_reserved = ntohl(b[3]);
+		r->v1.clock_seq_low		= ntohl(b[4]);
 
 		for (loop = 0; loop < 6; loop++)
-			r->node[loop] = ntohl(b[loop + 5]);
+			r->v1.node[loop] = ntohl(b[loop + 5]);
 
 		call->offset = 0;
 		call->unmarshall++;
@@ -453,7 +453,7 @@ static int afs_deliver_cb_probe(struct afs_call *call)
 static void SRXAFSCB_ProbeUuid(struct work_struct *work)
 {
 	struct afs_call *call = container_of(work, struct afs_call, work);
-	struct uuid_v1 *r = call->request;
+	uuid_t *r = call->request;
 
 	struct {
 		__be32	match;
@@ -476,7 +476,7 @@ static void SRXAFSCB_ProbeUuid(struct work_struct *work)
  */
 static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 {
-	struct uuid_v1 *r;
+	uuid_t *r;
 	unsigned loop;
 	__be32 *b;
 	int ret;
@@ -502,20 +502,20 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 		}
 
 		_debug("unmarshall UUID");
-		call->request = kmalloc(sizeof(struct uuid_v1), GFP_KERNEL);
+		call->request = kmalloc(sizeof(uuid_t), GFP_KERNEL);
 		if (!call->request)
 			return -ENOMEM;
 
 		b = call->buffer;
 		r = call->request;
-		r->time_low			= b[0];
-		r->time_mid			= htons(ntohl(b[1]));
-		r->time_hi_and_version		= htons(ntohl(b[2]));
-		r->clock_seq_hi_and_reserved 	= ntohl(b[3]);
-		r->clock_seq_low		= ntohl(b[4]);
+		r->v1.time_low			= b[0];
+		r->v1.time_mid			= htons(ntohl(b[1]));
+		r->v1.time_hi_and_version	= htons(ntohl(b[2]));
+		r->v1.clock_seq_hi_and_reserved = ntohl(b[3]);
+		r->v1.clock_seq_low		= ntohl(b[4]);
 
 		for (loop = 0; loop < 6; loop++)
-			r->node[loop] = ntohl(b[loop + 5]);
+			r->v1.node[loop] = ntohl(b[loop + 5]);
 
 		call->offset = 0;
 		call->unmarshall++;
@@ -568,13 +568,13 @@ static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 	memset(&reply, 0, sizeof(reply));
 	reply.ia.nifs = htonl(nifs);
 
-	reply.ia.uuid[0] = afs_uuid.time_low;
-	reply.ia.uuid[1] = htonl(ntohs(afs_uuid.time_mid));
-	reply.ia.uuid[2] = htonl(ntohs(afs_uuid.time_hi_and_version));
-	reply.ia.uuid[3] = htonl((s8) afs_uuid.clock_seq_hi_and_reserved);
-	reply.ia.uuid[4] = htonl((s8) afs_uuid.clock_seq_low);
+	reply.ia.uuid[0] = afs_uuid.v1.time_low;
+	reply.ia.uuid[1] = htonl(ntohs(afs_uuid.v1.time_mid));
+	reply.ia.uuid[2] = htonl(ntohs(afs_uuid.v1.time_hi_and_version));
+	reply.ia.uuid[3] = htonl((s8) afs_uuid.v1.clock_seq_hi_and_reserved);
+	reply.ia.uuid[4] = htonl((s8) afs_uuid.v1.clock_seq_low);
 	for (loop = 0; loop < 6; loop++)
-		reply.ia.uuid[loop + 5] = htonl((s8) afs_uuid.node[loop]);
+		reply.ia.uuid[loop + 5] = htonl((s8) afs_uuid.v1.node[loop]);
 
 	if (ifs) {
 		for (loop = 0; loop < nifs; loop++) {
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 393672997cc2..7de45c8686a2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -544,7 +544,7 @@ extern int afs_drop_inode(struct inode *);
  * main.c
  */
 extern struct workqueue_struct *afs_wq;
-extern struct uuid_v1 afs_uuid;
+extern uuid_t afs_uuid;
 
 /*
  * misc.c
diff --git a/fs/afs/main.c b/fs/afs/main.c
index 51d7d17bca57..75b3d3a8b1ba 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -31,7 +31,7 @@ static char *rootcell;
 module_param(rootcell, charp, 0);
 MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");
 
-struct uuid_v1 afs_uuid;
+uuid_t afs_uuid;
 struct workqueue_struct *afs_wq;
 
 /*
@@ -43,7 +43,7 @@ static int __init afs_init(void)
 
 	printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n");
 
-	generate_random_uuid((unsigned char *)&afs_uuid);
+	uuid_gen(&afs_uuid);
 
 	/* create workqueue */
 	ret = -ENOMEM;
-- 
2.11.0

[PATCH 07/16] uuid: remove struct uuid_v1

[Christoph Hellwig]

Unused now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/uuid.h | 24 ------------------------
 1 file changed, 24 deletions(-)

diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index af669f317780..28a5a894b926 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -19,30 +19,6 @@
 #include <uapi/linux/uuid.h>
 
 /*
- * V1 (time-based) UUID definition [RFC 4122].
- * - the timestamp is a 60-bit value, split 32/16/12, and goes in 100ns
- *   increments since midnight 15th October 1582
- *   - add AFS_UUID_TO_UNIX_TIME to convert unix time in 100ns units to UUID
- *     time
- * - the clock sequence is a 14-bit counter to avoid duplicate times
- */
-struct uuid_v1 {
-	__be32		time_low;			/* low part of timestamp */
-	__be16		time_mid;			/* mid part of timestamp */
-	__be16		time_hi_and_version;		/* high part of timestamp and version  */
-#define UUID_TO_UNIX_TIME	0x01b21dd213814000ULL
-#define UUID_TIMEHI_MASK	0x0fff
-#define UUID_VERSION_TIME	0x1000	/* time-based UUID */
-#define UUID_VERSION_NAME	0x3000	/* name-based UUID */
-#define UUID_VERSION_RANDOM	0x4000	/* (pseudo-)random generated UUID */
-	u8		clock_seq_hi_and_reserved;	/* clock seq hi and variant */
-#define UUID_CLOCKHI_MASK	0x3f
-#define UUID_VARIANT_STD	0x80
-	u8		clock_seq_low;			/* clock seq low */
-	u8		node[6];			/* spatially unique node ID (MAC addr) */
-};
-
-/*
  * The length of a UUID string ("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")
  * not including trailing NUL.
  */
-- 
2.11.0

[PATCH 08/16] xfs: remove uuid_getnodeuniq and xfs_uu_t

[Christoph Hellwig]

Directly use the v1 intepretation of uuid_t instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/uuid.c      | 25 -------------------------
 fs/xfs/uuid.h      |  1 -
 fs/xfs/xfs_mount.c |  6 +++++-
 3 files changed, 5 insertions(+), 27 deletions(-)

diff --git a/fs/xfs/uuid.c b/fs/xfs/uuid.c
index b83f76b6d410..937deaf2128d 100644
--- a/fs/xfs/uuid.c
+++ b/fs/xfs/uuid.c
@@ -17,31 +17,6 @@
  */
 #include <xfs.h>
 
-/* IRIX interpretation of an uuid_t */
-typedef struct {
-	__be32	uu_timelow;
-	__be16	uu_timemid;
-	__be16	uu_timehi;
-	__be16	uu_clockseq;
-	__be16	uu_node[3];
-} xfs_uu_t;
-
-/*
- * uuid_getnodeuniq - obtain the node unique fields of a UUID.
- *
- * This is not in any way a standard or condoned UUID function;
- * it just something that's needed for user-level file handles.
- */
-void
-uuid_getnodeuniq(uuid_t *uuid, int fsid [2])
-{
-	xfs_uu_t *uup = (xfs_uu_t *)uuid;
-
-	fsid[0] = (be16_to_cpu(uup->uu_clockseq) << 16) |
-		   be16_to_cpu(uup->uu_timemid);
-	fsid[1] = be32_to_cpu(uup->uu_timelow);
-}
-
 int
 uuid_is_nil(uuid_t *uuid)
 {
diff --git a/fs/xfs/uuid.h b/fs/xfs/uuid.h
index 4f1441ba4fa5..65b5cebf2f99 100644
--- a/fs/xfs/uuid.h
+++ b/fs/xfs/uuid.h
@@ -20,7 +20,6 @@
 
 extern int uuid_is_nil(uuid_t *uuid);
 extern int uuid_equal(uuid_t *uuid1, uuid_t *uuid2);
-extern void uuid_getnodeuniq(uuid_t *uuid, int fsid [2]);
 
 static inline void
 uuid_copy(uuid_t *dst, uuid_t *src)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 2eaf81859166..742e4a61c0bc 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -793,7 +793,11 @@ xfs_mountfs(
 	 *  Copies the low order bits of the timestamp and the randomly
 	 *  set "sequence" number out of a UUID.
 	 */
-	uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
+	mp->m_fixedfsid[0] =
+		((u32)sbp->sb_uuid.v1.clock_seq_hi_and_reserved << 24) |
+		((u32)sbp->sb_uuid.v1.clock_seq_low << 16) |
+		 be16_to_cpu(sbp->sb_uuid.v1.time_mid);
+	mp->m_fixedfsid[1] = be32_to_cpu(sbp->sb_uuid.v1.time_low);
 
 	mp->m_dmevmask = 0;	/* not persistent; set after each mount */
 
-- 
2.11.0

[PATCH 09/16] md: namespace private helper names

[Christoph Hellwig]

From: Amir Goldstein <amir73il@gmail.com>

The md private helper uuid_equal() collides with a generic helper
of the same name.

Rename the md private helper to md_uuid_equal() and do the same for
md_sb_equal().

Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 82f798be964f..65795cc4cb7d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -825,7 +825,7 @@ static int read_disk_sb(struct md_rdev *rdev, int size)
 	return -EINVAL;
 }
 
-static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
+static int md_uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
 {
 	return	sb1->set_uuid0 == sb2->set_uuid0 &&
 		sb1->set_uuid1 == sb2->set_uuid1 &&
@@ -833,7 +833,7 @@ static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
 		sb1->set_uuid3 == sb2->set_uuid3;
 }
 
-static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
+static int md_sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
 {
 	int ret;
 	mdp_super_t *tmp1, *tmp2;
@@ -1025,12 +1025,12 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 	} else {
 		__u64 ev1, ev2;
 		mdp_super_t *refsb = page_address(refdev->sb_page);
-		if (!uuid_equal(refsb, sb)) {
+		if (!md_uuid_equal(refsb, sb)) {
 			pr_warn("md: %s has different UUID to %s\n",
 				b, bdevname(refdev->bdev,b2));
 			goto abort;
 		}
-		if (!sb_equal(refsb, sb)) {
+		if (!md_sb_equal(refsb, sb)) {
 			pr_warn("md: %s has same UUID but different superblock to %s\n",
 				b, bdevname(refdev->bdev, b2));
 			goto abort;
-- 
2.11.0

[PATCH 10/16] uuid: hoist helpers uuid_equal() and uuid_copy() from xfs

[Christoph Hellwig]

From: Amir Goldstein <amir73il@gmail.com>

These helper are used to compare and copy two uuid_t type objects.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
[hch: also provide the respective guid_ versions]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/uuid.c        |  6 ------
 fs/xfs/uuid.h        |  7 -------
 include/linux/uuid.h | 20 ++++++++++++++++++++
 3 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/fs/xfs/uuid.c b/fs/xfs/uuid.c
index 937deaf2128d..737c186ea98b 100644
--- a/fs/xfs/uuid.c
+++ b/fs/xfs/uuid.c
@@ -30,9 +30,3 @@ uuid_is_nil(uuid_t *uuid)
 		if (*cp++) return 0;	/* not nil */
 	return 1;	/* is nil */
 }
-
-int
-uuid_equal(uuid_t *uuid1, uuid_t *uuid2)
-{
-	return memcmp(uuid1, uuid2, sizeof(uuid_t)) ? 0 : 1;
-}
diff --git a/fs/xfs/uuid.h b/fs/xfs/uuid.h
index 65b5cebf2f99..5aea49bf0963 100644
--- a/fs/xfs/uuid.h
+++ b/fs/xfs/uuid.h
@@ -19,12 +19,5 @@
 #define __XFS_SUPPORT_UUID_H__
 
 extern int uuid_is_nil(uuid_t *uuid);
-extern int uuid_equal(uuid_t *uuid1, uuid_t *uuid2);
-
-static inline void
-uuid_copy(uuid_t *dst, uuid_t *src)
-{
-	memcpy(dst, src, sizeof(uuid_t));
-}
 
 #endif	/* __XFS_SUPPORT_UUID_H__ */
diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index 28a5a894b926..b7fec8b266eb 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -29,11 +29,31 @@ static inline int guid_cmp(const guid_t u1, const guid_t u2)
 	return memcmp(&u1, &u2, sizeof(guid_t));
 }
 
+static inline bool guid_equal(const guid_t *u1, const guid_t *u2)
+{
+	return memcmp(u1, u2, sizeof(guid_t)) == 0;
+}
+
+static inline void guid_copy(guid_t *dst, const guid_t *src)
+{
+	memcpy(dst, src, sizeof(guid_t));
+}
+
 static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
 {
 	return memcmp(&u1, &u2, sizeof(uuid_t));
 }
 
+static inline bool uuid_equal(const uuid_t *u1, const uuid_t *u2)
+{
+	return memcmp(u1, u2, sizeof(uuid_t)) == 0;
+}
+
+static inline void uuid_copy(uuid_t *dst, const uuid_t *src)
+{
+	memcpy(dst, src, sizeof(uuid_t));
+}
+
 void generate_random_uuid(unsigned char uuid[16]);
 
 extern void guid_gen(guid_t *u);
-- 
2.11.0

[PATCH 11/16] uuid: hoist uuid_is_null() helper from libnvdimm

[Christoph Hellwig]

From: Amir Goldstein <amir73il@gmail.com>

Hoist the libnvdimm helper as an inline helper to linux/uuid.h
using an auxiliary const variable uuid_null in lib/uuid.c.

[hch: also add the guid variant.  Both do the same but I'd like
to keep casts to a minimum]

The common helper uses the new abstract type uuid_t * instead of
u8 *.

Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
[hch: added guid_is_null]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvdimm/btt_devs.c |  9 +--------
 include/linux/uuid.h      | 13 +++++++++++++
 lib/uuid.c                |  5 +++++
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 4b76af2b8715..734290d30557 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -222,13 +222,6 @@ struct device *nd_btt_create(struct nd_region *nd_region)
 	return dev;
 }
 
-static bool uuid_is_null(u8 *uuid)
-{
-	static const u8 null_uuid[16];
-
-	return (memcmp(uuid, null_uuid, 16) == 0);
-}
-
 /**
  * nd_btt_arena_is_valid - check if the metadata layout is valid
  * @nd_btt:	device with BTT geometry and backing device info
@@ -249,7 +242,7 @@ bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 		return false;
 
-	if (!uuid_is_null(super->parent_uuid))
+	if (!guid_is_null((guid_t *)&super->parent_uuid))
 		if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
 			return false;
 
diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index b7fec8b266eb..2f9bdc88079e 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -24,6 +24,9 @@
  */
 #define	UUID_STRING_LEN		36
 
+extern const guid_t guid_null;
+extern const uuid_t uuid_null;
+
 static inline int guid_cmp(const guid_t u1, const guid_t u2)
 {
 	return memcmp(&u1, &u2, sizeof(guid_t));
@@ -39,6 +42,11 @@ static inline void guid_copy(guid_t *dst, const guid_t *src)
 	memcpy(dst, src, sizeof(guid_t));
 }
 
+static inline bool guid_is_null(guid_t *guid)
+{
+	return guid_equal(guid, &guid_null);
+}
+
 static inline int uuid_cmp(const uuid_t u1, const uuid_t u2)
 {
 	return memcmp(&u1, &u2, sizeof(uuid_t));
@@ -54,6 +62,11 @@ static inline void uuid_copy(uuid_t *dst, const uuid_t *src)
 	memcpy(dst, src, sizeof(uuid_t));
 }
 
+static inline bool uuid_is_null(uuid_t *uuid)
+{
+	return uuid_equal(uuid, &uuid_null);
+}
+
 void generate_random_uuid(unsigned char uuid[16]);
 
 extern void guid_gen(guid_t *u);
diff --git a/lib/uuid.c b/lib/uuid.c
index 003bf6823003..25145bfb0eaa 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -21,6 +21,11 @@
 #include <linux/uuid.h>
 #include <linux/random.h>
 
+const guid_t guid_null;
+EXPORT_SYMBOL(guid_null);
+const uuid_t uuid_null;
+EXPORT_SYMBOL(uuid_null);
+
 const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 
-- 
2.11.0

[PATCH 12/16] xfs: use the common helper uuid_is_null()

[Christoph Hellwig]

From: Amir Goldstein <amir73il@gmail.com>

Use the common helper uuid_is_null() and remove the xfs specific
helper uuid_is_nil().

The common helper does not check for the NULL pointer value as
xfs helper did, but xfs code never calls the helper with a pointer
that can be NULL.

Conform comments and warning strings to use the term 'null uuid'
instead of 'nil uuid', because this is the terminology used by
lib/uuid.c and its users. It is also the terminology used in
userspace by libuuid and xfsprogs.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
[hch: remove now unused uuid.[ch]]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/Makefile          |  3 +--
 fs/xfs/uuid.c            | 32 --------------------------------
 fs/xfs/uuid.h            | 23 -----------------------
 fs/xfs/xfs_linux.h       |  1 -
 fs/xfs/xfs_log_recover.c |  6 +++---
 fs/xfs/xfs_mount.c       |  8 ++++----
 6 files changed, 8 insertions(+), 65 deletions(-)
 delete mode 100644 fs/xfs/uuid.c
 delete mode 100644 fs/xfs/uuid.h

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 5c90f82b8f6b..a6e955bfead8 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -98,8 +98,7 @@ xfs-y				+= xfs_aops.o \
 				   xfs_sysfs.o \
 				   xfs_trans.o \
 				   xfs_xattr.o \
-				   kmem.o \
-				   uuid.o
+				   kmem.o
 
 # low-level transaction/log code
 xfs-y				+= xfs_log.o \
diff --git a/fs/xfs/uuid.c b/fs/xfs/uuid.c
deleted file mode 100644
index 737c186ea98b..000000000000
--- a/fs/xfs/uuid.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
- * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- */
-#include <xfs.h>
-
-int
-uuid_is_nil(uuid_t *uuid)
-{
-	int	i;
-	char	*cp = (char *)uuid;
-
-	if (uuid == NULL)
-		return 0;
-	/* implied check of version number here... */
-	for (i = 0; i < sizeof *uuid; i++)
-		if (*cp++) return 0;	/* not nil */
-	return 1;	/* is nil */
-}
diff --git a/fs/xfs/uuid.h b/fs/xfs/uuid.h
deleted file mode 100644
index 5aea49bf0963..000000000000
--- a/fs/xfs/uuid.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
- * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- */
-#ifndef __XFS_SUPPORT_UUID_H__
-#define __XFS_SUPPORT_UUID_H__
-
-extern int uuid_is_nil(uuid_t *uuid);
-
-#endif	/* __XFS_SUPPORT_UUID_H__ */
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 2c33d915e550..2d167fe643ec 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -43,7 +43,6 @@ typedef __u32			xfs_nlink_t;
 
 #include "kmem.h"
 #include "mrlock.h"
-#include "uuid.h"
 
 #include <linux/semaphore.h>
 #include <linux/mm.h>
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index cd0b077deb35..8cec1e5505a4 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -352,13 +352,13 @@ xlog_header_check_mount(
 {
 	ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));
 
-	if (uuid_is_nil(&head->h_fs_uuid)) {
+	if (uuid_is_null(&head->h_fs_uuid)) {
 		/*
 		 * IRIX doesn't write the h_fs_uuid or h_fmt fields. If
-		 * h_fs_uuid is nil, we assume this log was last mounted
+		 * h_fs_uuid is null, we assume this log was last mounted
 		 * by IRIX and continue.
 		 */
-		xfs_warn(mp, "nil uuid in log - IRIX style log");
+		xfs_warn(mp, "null uuid in log - IRIX style log");
 	} else if (unlikely(!uuid_equal(&mp->m_sb.sb_uuid, &head->h_fs_uuid))) {
 		xfs_warn(mp, "log has mismatched uuid - can't recover");
 		xlog_header_check_dump(mp, head);
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 742e4a61c0bc..682b336a7a6a 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -80,14 +80,14 @@ xfs_uuid_mount(
 	if (mp->m_flags & XFS_MOUNT_NOUUID)
 		return 0;
 
-	if (uuid_is_nil(uuid)) {
-		xfs_warn(mp, "Filesystem has nil UUID - can't mount");
+	if (uuid_is_null(uuid)) {
+		xfs_warn(mp, "Filesystem has null UUID - can't mount");
 		return -EINVAL;
 	}
 
 	mutex_lock(&xfs_uuid_table_mutex);
 	for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
-		if (uuid_is_nil(&xfs_uuid_table[i])) {
+		if (uuid_is_null(&xfs_uuid_table[i])) {
 			hole = i;
 			continue;
 		}
@@ -124,7 +124,7 @@ xfs_uuid_unmount(
 
 	mutex_lock(&xfs_uuid_table_mutex);
 	for (i = 0; i < xfs_uuid_table_size; i++) {
-		if (uuid_is_nil(&xfs_uuid_table[i]))
+		if (uuid_is_null(&xfs_uuid_table[i]))
 			continue;
 		if (!uuid_equal(uuid, &xfs_uuid_table[i]))
 			continue;
-- 
2.11.0

[PATCH 13/16] block: remove blk_part_pack_uuid

[Christoph Hellwig]

This helper was only used by IMA of all things, which would get spurious
errors if CONFIG_BLOCK is disabled.  Just opencode the call there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/genhd.h               | 11 -----------
 security/integrity/ima/ima_policy.c |  6 ++----
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index acff9437e5c3..e619fae2f037 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -219,12 +219,6 @@ static inline struct gendisk *part_to_disk(struct hd_struct *part)
 	return NULL;
 }
 
-static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
-{
-	uuid_be_to_bin(uuid_str, (uuid_be *)to);
-	return 0;
-}
-
 static inline int disk_max_parts(struct gendisk *disk)
 {
 	if (disk->flags & GENHD_FL_EXT_DEVT)
@@ -736,11 +730,6 @@ static inline dev_t blk_lookup_devt(const char *name, int partno)
 	dev_t devt = MKDEV(0, 0);
 	return devt;
 }
-
-static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
-{
-	return -EINVAL;
-}
 #endif /* CONFIG_BLOCK */
 
 #endif /* _LINUX_GENHD_H */
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 3ab1067db624..4d1178610145 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -717,10 +717,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				break;
 			}
 
-			result = blk_part_pack_uuid(args[0].from,
-						    entry->fsuuid);
-			if (!result)
-				entry->flags |= IMA_FSUUID;
+			uuid_to_bin(args[0].from, (uuid_t *)entry->fsuuid);
+			entry->flags |= IMA_FSUUID;
 			break;
 		case Opt_uid_gt:
 		case Opt_euid_gt:
-- 
2.11.0

[PATCH 14/16] block: remove blk_part_pack_uuid

[Christoph Hellwig]

This helper was only used by IMA of all things, which would get spurious
errors if CONFIG_BLOCK is disabled.  Just opencode the call there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[andy: correctly handle error returns from uuid_to_bin]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 security/integrity/ima/ima_policy.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 4d1178610145..49fbc3e8f012 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -717,8 +717,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				break;
 			}
 
-			uuid_to_bin(args[0].from, (uuid_t *)entry->fsuuid);
-			entry->flags |= IMA_FSUUID;
+			result = uuid_to_bin(args[0].from, (uuid_t *)&entry->fsuuid);
+			if (!result)
+				entry->flags |= IMA_FSUUID;
 			break;
 		case Opt_uid_gt:
 		case Opt_euid_gt:
-- 
2.11.0

Re: [PATCH 14/16] block: remove blk_part_pack_uuid

[Christoph Hellwig]

On Wed, May 10, 2017 at 08:02:12PM +0200, Christoph Hellwig wrote:
> This helper was only used by IMA of all things, which would get spurious
> errors if CONFIG_BLOCK is disabled.  Just opencode the call there.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> [andy: correctly handle error returns from uuid_to_bin]
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  security/integrity/ima/ima_policy.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 4d1178610145..49fbc3e8f012 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -717,8 +717,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>  				break;
>  			}
>  
> -			uuid_to_bin(args[0].from, (uuid_t *)entry->fsuuid);
> -			entry->flags |= IMA_FSUUID;
> +			result = uuid_to_bin(args[0].from, (uuid_t *)&entry->fsuuid);
> +			if (!result)
> +				entry->flags |= IMA_FSUUID;

This should have been folded into the previous patch..

[PATCH 15/16] ima/policy: switch to use uuid_t

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 security/integrity/ima/ima_policy.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 49fbc3e8f012..da3e7d50e0d7 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -61,7 +61,7 @@ struct ima_rule_entry {
 	enum ima_hooks func;
 	int mask;
 	unsigned long fsmagic;
-	u8 fsuuid[16];
+	uuid_t fsuuid;
 	kuid_t uid;
 	kuid_t fowner;
 	bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
@@ -244,7 +244,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	    && rule->fsmagic != inode->i_sb->s_magic)
 		return false;
 	if ((rule->flags & IMA_FSUUID) &&
-	    memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+	    memcmp(&rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
 		return false;
 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 		return false;
@@ -711,13 +711,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 		case Opt_fsuuid:
 			ima_log_string(ab, "fsuuid", args[0].from);
 
-			if (memchr_inv(entry->fsuuid, 0x00,
-				       sizeof(entry->fsuuid))) {
+			if (uuid_is_null(&entry->fsuuid)) {
 				result = -EINVAL;
 				break;
 			}
 
-			result = uuid_to_bin(args[0].from, (uuid_t *)&entry->fsuuid);
+			result = uuid_to_bin(args[0].from, &entry->fsuuid);
 			if (!result)
 				entry->flags |= IMA_FSUUID;
 			break;
@@ -1086,7 +1085,7 @@ int ima_policy_show(struct seq_file *m, void *v)
 	}
 
 	if (entry->flags & IMA_FSUUID) {
-		seq_printf(m, "fsuuid=%pU", entry->fsuuid);
+		seq_printf(m, "fsuuid=%pU", &entry->fsuuid);
 		seq_puts(m, " ");
 	}
 
-- 
2.11.0

[PATCH 16/16] fs: switch ->s_uuid to uuid_t

[Christoph Hellwig]

For some file systems we still memcpy into it, but in various places this
already allows us to use the proper uuid helpers.  More to come..

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/xen/tmem.c                  |  6 +++---
 fs/ext4/super.c                     |  2 +-
 fs/f2fs/super.c                     |  2 +-
 fs/gfs2/ops_fstype.c                |  2 +-
 fs/gfs2/sys.c                       | 22 +++++-----------------
 fs/ocfs2/super.c                    |  2 +-
 fs/xfs/xfs_mount.c                  |  2 +-
 include/linux/cleancache.h          |  2 +-
 include/linux/fs.h                  |  5 +++--
 mm/cleancache.c                     |  2 +-
 security/integrity/evm/evm_crypto.c |  2 +-
 security/integrity/ima/ima_policy.c |  2 +-
 12 files changed, 20 insertions(+), 31 deletions(-)

diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c
index 4ac2ca8a7656..bf13d1ec51f3 100644
--- a/drivers/xen/tmem.c
+++ b/drivers/xen/tmem.c
@@ -233,12 +233,12 @@ static int tmem_cleancache_init_fs(size_t pagesize)
 	return xen_tmem_new_pool(uuid_private, 0, pagesize);
 }
 
-static int tmem_cleancache_init_shared_fs(char *uuid, size_t pagesize)
+static int tmem_cleancache_init_shared_fs(uuid_t *uuid, size_t pagesize)
 {
 	struct tmem_pool_uuid shared_uuid;
 
-	shared_uuid.uuid_lo = *(u64 *)uuid;
-	shared_uuid.uuid_hi = *(u64 *)(&uuid[8]);
+	shared_uuid.uuid_lo = *(u64 *)&uuid->b[0];
+	shared_uuid.uuid_hi = *(u64 *)&uuid->b[8];
 	return xen_tmem_new_pool(shared_uuid, TMEM_POOL_SHARED, pagesize);
 }
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c90edf09b0c3..b53e8b3082c0 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3951,7 +3951,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		sb->s_qcop = &ext4_qctl_operations;
 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
 #endif
-	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
+	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
 
 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
 	mutex_init(&sbi->s_orphan_lock);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 83355ec4a92c..0b89b0b7b9f7 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1937,7 +1937,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_time_gran = 1;
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
-	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+	memcpy(&sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
 
 	/* init f2fs-specific super block info */
 	sbi->valid_super_block = valid_super_block;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index ed67548b286c..b92135c202c2 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -203,7 +203,7 @@ static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 
 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
-	memcpy(s->s_uuid, str->sb_uuid, 16);
+	memcpy(&s->s_uuid, str->sb_uuid, 16);
 }
 
 /**
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 7a515345610c..e77bc52b468f 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -71,25 +71,14 @@ static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
 	return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname);
 }
 
-static int gfs2_uuid_valid(const u8 *uuid)
-{
-	int i;
-
-	for (i = 0; i < 16; i++) {
-		if (uuid[i])
-			return 1;
-	}
-	return 0;
-}
-
 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 {
 	struct super_block *s = sdp->sd_vfs;
-	const u8 *uuid = s->s_uuid;
+
 	buf[0] = '\0';
-	if (!gfs2_uuid_valid(uuid))
+	if (uuid_is_null(&s->s_uuid))
 		return 0;
-	return snprintf(buf, PAGE_SIZE, "%pUB\n", uuid);
+	return snprintf(buf, PAGE_SIZE, "%pUB\n", &s->s_uuid);
 }
 
 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
@@ -712,14 +701,13 @@ static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
 {
 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
 	struct super_block *s = sdp->sd_vfs;
-	const u8 *uuid = s->s_uuid;
 
 	add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
 	add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
 	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))
 		add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);
-	if (gfs2_uuid_valid(uuid))
-		add_uevent_var(env, "UUID=%pUB", uuid);
+	if (!uuid_is_null(&s->s_uuid))
+		add_uevent_var(env, "UUID=%pUB", &s->s_uuid);
 	return 0;
 }
 
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index ca1646fbcaef..83005f486451 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2062,7 +2062,7 @@ static int ocfs2_initialize_super(struct super_block *sb,
 	cbits = le32_to_cpu(di->id2.i_super.s_clustersize_bits);
 	bbits = le32_to_cpu(di->id2.i_super.s_blocksize_bits);
 	sb->s_maxbytes = ocfs2_max_file_offset(bbits, cbits);
-	memcpy(sb->s_uuid, di->id2.i_super.s_uuid,
+	memcpy(&sb->s_uuid, di->id2.i_super.s_uuid,
 	       sizeof(di->id2.i_super.s_uuid));
 
 	osb->osb_dx_mask = (1 << (cbits - bbits)) - 1;
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 682b336a7a6a..93a420160964 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -75,7 +75,7 @@ xfs_uuid_mount(
 
 	/* Publish UUID in struct super_block */
 	BUILD_BUG_ON(sizeof(mp->m_super->s_uuid) != sizeof(uuid_t));
-	memcpy(&mp->m_super->s_uuid, uuid, sizeof(uuid_t));
+	uuid_copy(&mp->m_super->s_uuid, uuid);
 
 	if (mp->m_flags & XFS_MOUNT_NOUUID)
 		return 0;
diff --git a/include/linux/cleancache.h b/include/linux/cleancache.h
index fccf7f44139d..bbb3712dd892 100644
--- a/include/linux/cleancache.h
+++ b/include/linux/cleancache.h
@@ -27,7 +27,7 @@ struct cleancache_filekey {
 
 struct cleancache_ops {
 	int (*init_fs)(size_t);
-	int (*init_shared_fs)(char *uuid, size_t);
+	int (*init_shared_fs)(uuid_t *uuid, size_t);
 	int (*get_page)(int, struct cleancache_filekey,
 			pgoff_t, struct page *);
 	void (*put_page)(int, struct cleancache_filekey,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 26488b419965..cdffd2f86aa0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -30,6 +30,7 @@
 #include <linux/percpu-rwsem.h>
 #include <linux/workqueue.h>
 #include <linux/delayed_call.h>
+#include <linux/uuid.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -1326,8 +1327,8 @@ struct super_block {
 
 	struct sb_writers	s_writers;
 
-	char s_id[32];				/* Informational name */
-	u8 s_uuid[16];				/* UUID */
+	char			s_id[32];	/* Informational name */
+	uuid_t			s_uuid;		/* UUID */
 
 	void 			*s_fs_info;	/* Filesystem private info */
 	unsigned int		s_max_links;
diff --git a/mm/cleancache.c b/mm/cleancache.c
index ba5d8f3e6d68..f7b9fdc79d97 100644
--- a/mm/cleancache.c
+++ b/mm/cleancache.c
@@ -130,7 +130,7 @@ void __cleancache_init_shared_fs(struct super_block *sb)
 	int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
 
 	if (cleancache_ops) {
-		pool_id = cleancache_ops->init_shared_fs(sb->s_uuid, PAGE_SIZE);
+		pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE);
 		if (pool_id < 0)
 			pool_id = CLEANCACHE_NO_POOL;
 	}
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index d7f282d75cc1..1d32cd20009a 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -164,7 +164,7 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
 	hmac_misc.mode = inode->i_mode;
 	crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc));
 	if (evm_hmac_attrs & EVM_ATTR_FSUUID)
-		crypto_shash_update(desc, inode->i_sb->s_uuid,
+		crypto_shash_update(desc, &inode->i_sb->s_uuid.b[0],
 				    sizeof(inode->i_sb->s_uuid));
 	crypto_shash_final(desc, digest);
 }
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index da3e7d50e0d7..659dbcc83d2f 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -244,7 +244,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	    && rule->fsmagic != inode->i_sb->s_magic)
 		return false;
 	if ((rule->flags & IMA_FSUUID) &&
-	    memcmp(&rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+	    !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
 		return false;
 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 		return false;
-- 
2.11.0

Re: [PATCH 16/16] fs: switch ->s_uuid to uuid_t

[Amir Goldstein]

On Wed, May 10, 2017 at 9:02 PM, Christoph Hellwig <hch@lst.de> wrote:
> For some file systems we still memcpy into it, but in various places this
> already allows us to use the proper uuid helpers.  More to come..
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

Series looks good!

My main concern is that filesystems with char uuid[16] are here to stay,
or maybe, will be converted slowly.

Considering this, perhaps we should have a helper/macro to copy from
char[16] to *uuid_t and maybe  BUILD_BUG_ON the size comparison?
#define bytes_to_uuid(dst, src) ...


> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 682b336a7a6a..93a420160964 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -75,7 +75,7 @@ xfs_uuid_mount(
>
>         /* Publish UUID in struct super_block */
>         BUILD_BUG_ON(sizeof(mp->m_super->s_uuid) != sizeof(uuid_t));

This BUILD_BUG is no longer needed.

> -       memcpy(&mp->m_super->s_uuid, uuid, sizeof(uuid_t));
> +       uuid_copy(&mp->m_super->s_uuid, uuid);
>
>         if (mp->m_flags & XFS_MOUNT_NOUUID)
>                 return 0;
[...]

> diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
> index d7f282d75cc1..1d32cd20009a 100644
> --- a/security/integrity/evm/evm_crypto.c
> +++ b/security/integrity/evm/evm_crypto.c
> @@ -164,7 +164,7 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
>         hmac_misc.mode = inode->i_mode;
>         crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc));
>         if (evm_hmac_attrs & EVM_ATTR_FSUUID)
> -               crypto_shash_update(desc, inode->i_sb->s_uuid,
> +               crypto_shash_update(desc, &inode->i_sb->s_uuid.b[0],

I wonder if 'inode->i_sb->s_uuid.b' would have been better here

Cheers,
Amir.

Re: [PATCH 16/16] fs: switch ->s_uuid to uuid_t

[Christoph Hellwig]

On Wed, May 10, 2017 at 10:08:25PM +0300, Amir Goldstein wrote:
> On Wed, May 10, 2017 at 9:02 PM, Christoph Hellwig <hch@lst.de> wrote:
> > For some file systems we still memcpy into it, but in various places this
> > already allows us to use the proper uuid helpers.  More to come..
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> 
> Series looks good!
> 
> My main concern is that filesystems with char uuid[16] are here to stay,
> or maybe, will be converted slowly.

I'll take a stab to convert them ASAP, and add s_uuid support for you
to more file systems once this initial series is done.

> 
> Considering this, perhaps we should have a helper/macro to copy from
> char[16] to *uuid_t and maybe  BUILD_BUG_ON the size comparison?
> #define bytes_to_uuid(dst, src) ...

If the mix of proper types and u8 arrays was to stay that'd be the way
to go, but I'd rather fix things up in a merge window or two instead
of leaving us in a transitionary state forever.

Re: [PATCH 03/16] uuid: rename uuid types

[David Howells]

Christoph Hellwig <hch@lst.de> wrote:

> -#define NULL_UUID_LE							\
> -	UUID_LE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
> -		0x00, 0x00, 0x00, 0x00)
> +#define NULL_GUID							\
> +	GUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
> +	     0x00, 0x00, 0x00, 0x00)
>  
> -#define NULL_UUID_BE							\
> -	UUID_BE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
> -		0x00, 0x00, 0x00, 0x00)
> +#define NULL_UUID							\
> +	UUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	\
> +	     0x00, 0x00, 0x00, 0x00)

These are UAPI and ought not to be renamed.

David

Re: [PATCH 03/16] uuid: rename uuid types

[Andy Shevchenko]

On Wed, 2017-05-10 at 19:20 +0100, David Howells wrote:
> Christoph Hellwig <hch@lst.de> wrote:
> 
> > -#define NULL_UUID_LE						
> > 	\
> > -	UUID_LE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,
> > 	\
> > -		0x00, 0x00, 0x00, 0x00)
> > +#define NULL_GUID							
> > \
> > +	GUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	
> > \
> > +	     0x00, 0x00, 0x00, 0x00)
> >  
> > -#define NULL_UUID_BE						
> > 	\
> > -	UUID_BE(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,
> > 	\
> > -		0x00, 0x00, 0x00, 0x00)
> > +#define NULL_UUID							
> > \
> > +	UUID(0x00000000, 0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00,	
> > \
> > +	     0x00, 0x00, 0x00, 0x00)
> 
> These are UAPI and ought not to be renamed.
> 

Good point. I see in the branch it's already fixed.


-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH 05/16] uuid: add the v1 layout to uuid_t

[David Howells]

Christoph Hellwig <hch@lst.de> wrote:

> Turn the content of uuid_t into a union and add the fields for the v1
> interpretation to it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: David Howells <dhowells@redhat.com>

Re: [PATCH 06/16] afs: switch to use uuid_t and uuid_gen

[David Howells]

Christoph Hellwig <hch@lst.de> wrote:

> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: David Howells <dhowells@redhat.com>