* [PATCH 1/4] btrfs: add xxhash64 to checksumming algorithms
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
@ 2019-10-07 9:11 ` Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 2/4] btrfs: add sha256 " Johannes Thumshirn
` (3 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Johannes Thumshirn @ 2019-10-07 9:11 UTC (permalink / raw)
To: David Sterba; +Cc: Linux BTRFS Mailinglist, Nikolay Borisov, Johannes Thumshirn
Add xxhash64 to the list of possible checksumming algorithms used by
BTRFS.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
fs/btrfs/Kconfig | 1 +
fs/btrfs/ctree.c | 1 +
fs/btrfs/disk-io.c | 1 +
fs/btrfs/super.c | 1 +
include/uapi/linux/btrfs_tree.h | 1 +
5 files changed, 5 insertions(+)
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 38651fae7f21..6d5a01c57da3 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -5,6 +5,7 @@ config BTRFS_FS
select CRYPTO
select CRYPTO_CRC32C
select LIBCRC32C
+ select CRYPTO_XXHASH
select ZLIB_INFLATE
select ZLIB_DEFLATE
select LZO_COMPRESS
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3a4d8e27e565..a1b317cf193b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -34,6 +34,7 @@ static const struct btrfs_csums {
const char *name;
} btrfs_csums[] = {
[BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
+ [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" },
};
int btrfs_super_csum_size(const struct btrfs_super_block *s)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ea40898d49eb..b0a6904b6139 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -352,6 +352,7 @@ static bool btrfs_supported_super_csum(u16 csum_type)
{
switch (csum_type) {
case BTRFS_CSUM_TYPE_CRC32:
+ case BTRFS_CSUM_TYPE_XXHASH:
return true;
default:
return false;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d5d15a19f51d..c91cdf123cd8 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2462,3 +2462,4 @@ module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");
MODULE_SOFTDEP("pre: crc32c");
+MODULE_SOFTDEP("pre: xxhash64");
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index b65c7ee75bc7..ba2f125a3a1c 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -302,6 +302,7 @@
/* csum types */
enum btrfs_csum_type {
BTRFS_CSUM_TYPE_CRC32 = 0,
+ BTRFS_CSUM_TYPE_XXHASH = 1,
};
/*
--
2.16.4
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 2/4] btrfs: add sha256 to checksumming algorithms
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 1/4] btrfs: add xxhash64 to checksumming algorithms Johannes Thumshirn
@ 2019-10-07 9:11 ` Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 3/4] btrfs: sysfs: export supported checksums Johannes Thumshirn
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Johannes Thumshirn @ 2019-10-07 9:11 UTC (permalink / raw)
To: David Sterba; +Cc: Linux BTRFS Mailinglist, Nikolay Borisov, Johannes Thumshirn
Add sha256 to the list of possible checksumming algorithms used by BTRFS.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
fs/btrfs/Kconfig | 1 +
fs/btrfs/ctree.c | 1 +
fs/btrfs/disk-io.c | 1 +
fs/btrfs/super.c | 1 +
include/uapi/linux/btrfs_tree.h | 1 +
5 files changed, 5 insertions(+)
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 6d5a01c57da3..75b6d10c9845 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -6,6 +6,7 @@ config BTRFS_FS
select CRYPTO_CRC32C
select LIBCRC32C
select CRYPTO_XXHASH
+ select CRYPTO_SHA256
select ZLIB_INFLATE
select ZLIB_DEFLATE
select LZO_COMPRESS
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a1b317cf193b..b66509ee62eb 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -35,6 +35,7 @@ static const struct btrfs_csums {
} btrfs_csums[] = {
[BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
[BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" },
+ [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" },
};
int btrfs_super_csum_size(const struct btrfs_super_block *s)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b0a6904b6139..99feff25bbef 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -353,6 +353,7 @@ static bool btrfs_supported_super_csum(u16 csum_type)
switch (csum_type) {
case BTRFS_CSUM_TYPE_CRC32:
case BTRFS_CSUM_TYPE_XXHASH:
+ case BTRFS_CSUM_TYPE_SHA256:
return true;
default:
return false;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c91cdf123cd8..36440336c08b 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2463,3 +2463,4 @@ module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");
MODULE_SOFTDEP("pre: crc32c");
MODULE_SOFTDEP("pre: xxhash64");
+MODULE_SOFTDEP("pre: sha256");
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index ba2f125a3a1c..838cfd0af5c3 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -303,6 +303,7 @@
enum btrfs_csum_type {
BTRFS_CSUM_TYPE_CRC32 = 0,
BTRFS_CSUM_TYPE_XXHASH = 1,
+ BTRFS_CSUM_TYPE_SHA256 = 2,
};
/*
--
2.16.4
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 3/4] btrfs: sysfs: export supported checksums
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 1/4] btrfs: add xxhash64 to checksumming algorithms Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 2/4] btrfs: add sha256 " Johannes Thumshirn
@ 2019-10-07 9:11 ` Johannes Thumshirn
2019-10-07 15:36 ` Nikolay Borisov
2019-10-07 9:11 ` [PATCH 4/4] btrfs: show used checksum driver per filesystem in sysfs Johannes Thumshirn
2019-10-07 14:58 ` [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Nikolay Borisov
4 siblings, 1 reply; 10+ messages in thread
From: Johannes Thumshirn @ 2019-10-07 9:11 UTC (permalink / raw)
To: David Sterba; +Cc: Linux BTRFS Mailinglist, Nikolay Borisov, Johannes Thumshirn
From: David Sterba <dsterba@suse.com>
Export supported checksum algorithms via sysfs.
Co-developed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
fs/btrfs/ctree.c | 5 +++++
fs/btrfs/ctree.h | 2 ++
fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 40 insertions(+)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b66509ee62eb..5debd74dc61c 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type)
return btrfs_csums[csum_type].name;
}
+size_t btrfs_get_num_csums(void)
+{
+ return ARRAY_SIZE(btrfs_csums);
+}
+
struct btrfs_path *btrfs_alloc_path(void)
{
return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d17e79a40930..0180554f6970 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2165,6 +2165,8 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
int btrfs_super_csum_size(const struct btrfs_super_block *s);
const char *btrfs_super_csum_name(u16 csum_type);
+size_t btrfs_get_num_csums(void);
+
/*
* The leaf data grows from end-to-front in the node.
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index f6d3c80f2e28..aeebbdfe1a98 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -246,6 +246,28 @@ static umode_t btrfs_feature_visible(struct kobject *kobj,
return mode;
}
+static ssize_t btrfs_supported_checksums_show(struct kobject *kobj,
+ struct kobj_attribute *a,
+ char *buf)
+{
+ ssize_t ret = 0;
+ int i;
+
+ for (i = 0; i < btrfs_get_num_csums(); i++) {
+ /*
+ * This "trick" only works as long as 'enum btrfs_csum_type' has
+ * no holes in it
+ */
+ ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
+ (i == 0 ? "" : ", "),
+ btrfs_super_csum_name(i));
+
+ }
+
+ ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n");
+ return ret;
+}
+
BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
@@ -259,6 +281,14 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
+static struct btrfs_feature_attr btrfs_attr_features_checksums_name = {
+ .kobj_attr = __INIT_KOBJ_ATTR(supported_checksums, S_IRUGO,
+ btrfs_supported_checksums_show,
+ NULL),
+ .feature_set = FEAT_INCOMPAT,
+ .feature_bit = 0,
+};
+
static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(mixed_backref),
BTRFS_FEAT_ATTR_PTR(default_subvol),
@@ -272,6 +302,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(no_holes),
BTRFS_FEAT_ATTR_PTR(metadata_uuid),
BTRFS_FEAT_ATTR_PTR(free_space_tree),
+
+ &btrfs_attr_features_checksums_name.kobj_attr.attr,
+
NULL
};
--
2.16.4
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH 3/4] btrfs: sysfs: export supported checksums
2019-10-07 9:11 ` [PATCH 3/4] btrfs: sysfs: export supported checksums Johannes Thumshirn
@ 2019-10-07 15:36 ` Nikolay Borisov
2019-10-07 15:46 ` David Sterba
0 siblings, 1 reply; 10+ messages in thread
From: Nikolay Borisov @ 2019-10-07 15:36 UTC (permalink / raw)
To: Johannes Thumshirn, David Sterba; +Cc: Linux BTRFS Mailinglist
On 7.10.19 г. 12:11 ч., Johannes Thumshirn wrote:
> From: David Sterba <dsterba@suse.com>
>
> Export supported checksum algorithms via sysfs.
>
> Co-developed-by: David Sterba <dsterba@suse.com>
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---
> fs/btrfs/ctree.c | 5 +++++
> fs/btrfs/ctree.h | 2 ++
> fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++
> 3 files changed, 40 insertions(+)
>
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index b66509ee62eb..5debd74dc61c 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type)
> return btrfs_csums[csum_type].name;
> }
>
> +size_t btrfs_get_num_csums(void)
> +{
> + return ARRAY_SIZE(btrfs_csums);
> +}
nit: This function is used only once and the ARRAY_SIZE() macro is
descriptive enough, why not just remove it and opencoude the call to
array_size
> +
> struct btrfs_path *btrfs_alloc_path(void)
> {
> return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index d17e79a40930..0180554f6970 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -2165,6 +2165,8 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
>
> int btrfs_super_csum_size(const struct btrfs_super_block *s);
> const char *btrfs_super_csum_name(u16 csum_type);
> +size_t btrfs_get_num_csums(void);
> +
>
> /*
> * The leaf data grows from end-to-front in the node.
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index f6d3c80f2e28..aeebbdfe1a98 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -246,6 +246,28 @@ static umode_t btrfs_feature_visible(struct kobject *kobj,
> return mode;
> }
>
> +static ssize_t btrfs_supported_checksums_show(struct kobject *kobj,
> + struct kobj_attribute *a,
> + char *buf)
> +{
> + ssize_t ret = 0;
> + int i;
> +
> + for (i = 0; i < btrfs_get_num_csums(); i++) {
> + /*
> + * This "trick" only works as long as 'enum btrfs_csum_type' has
> + * no holes in it
> + */
> + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
> + (i == 0 ? "" : ", "),
> + btrfs_super_csum_name(i));
> +
> + }
> +
> + ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n");
> + return ret;
> +}
> +
> BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
> BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
> BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
> @@ -259,6 +281,14 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
> BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
> BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
>
> +static struct btrfs_feature_attr btrfs_attr_features_checksums_name = {
> + .kobj_attr = __INIT_KOBJ_ATTR(supported_checksums, S_IRUGO,
> + btrfs_supported_checksums_show,
> + NULL),
> + .feature_set = FEAT_INCOMPAT,
> + .feature_bit = 0,
> +};
> +
> static struct attribute *btrfs_supported_feature_attrs[] = {
> BTRFS_FEAT_ATTR_PTR(mixed_backref),
> BTRFS_FEAT_ATTR_PTR(default_subvol),
> @@ -272,6 +302,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
> BTRFS_FEAT_ATTR_PTR(no_holes),
> BTRFS_FEAT_ATTR_PTR(metadata_uuid),
> BTRFS_FEAT_ATTR_PTR(free_space_tree),
> +
> + &btrfs_attr_features_checksums_name.kobj_attr.attr,
> +
> NULL
> };
>
>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 3/4] btrfs: sysfs: export supported checksums
2019-10-07 15:36 ` Nikolay Borisov
@ 2019-10-07 15:46 ` David Sterba
2019-10-08 6:47 ` Johannes Thumshirn
0 siblings, 1 reply; 10+ messages in thread
From: David Sterba @ 2019-10-07 15:46 UTC (permalink / raw)
To: Nikolay Borisov; +Cc: Johannes Thumshirn, David Sterba, Linux BTRFS Mailinglist
On Mon, Oct 07, 2019 at 06:36:14PM +0300, Nikolay Borisov wrote:
>
>
> On 7.10.19 г. 12:11 ч., Johannes Thumshirn wrote:
> > From: David Sterba <dsterba@suse.com>
> >
> > Export supported checksum algorithms via sysfs.
> >
> > Co-developed-by: David Sterba <dsterba@suse.com>
> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> > ---
> > fs/btrfs/ctree.c | 5 +++++
> > fs/btrfs/ctree.h | 2 ++
> > fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++
> > 3 files changed, 40 insertions(+)
> >
> > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> > index b66509ee62eb..5debd74dc61c 100644
> > --- a/fs/btrfs/ctree.c
> > +++ b/fs/btrfs/ctree.c
> > @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type)
> > return btrfs_csums[csum_type].name;
> > }
> >
> > +size_t btrfs_get_num_csums(void)
> > +{
> > + return ARRAY_SIZE(btrfs_csums);
> > +}
>
> nit: This function is used only once and the ARRAY_SIZE() macro is
> descriptive enough, why not just remove it and opencoude the call to
> array_size
Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant.
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 3/4] btrfs: sysfs: export supported checksums
2019-10-07 15:46 ` David Sterba
@ 2019-10-08 6:47 ` Johannes Thumshirn
2019-10-08 11:40 ` David Sterba
0 siblings, 1 reply; 10+ messages in thread
From: Johannes Thumshirn @ 2019-10-08 6:47 UTC (permalink / raw)
To: dsterba, Nikolay Borisov, David Sterba, Linux BTRFS Mailinglist
On 07/10/2019 17:46, David Sterba wrote:
[...]
>> nit: This function is used only once and the ARRAY_SIZE() macro is
>> descriptive enough, why not just remove it and opencoude the call to
>> array_size
>
> Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant.
Nope, btrfs_csums[] is defined in ctree.c, so I can't get the size of
this array outside of ctree.c. And it was moved to ctree.c from ctree.h
on request by David.
--
Johannes Thumshirn SUSE Labs Filesystems
jthumshirn@suse.de +49 911 74053 689
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5
90409 Nürnberg
Germany
(HRB 247165, AG München)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 3/4] btrfs: sysfs: export supported checksums
2019-10-08 6:47 ` Johannes Thumshirn
@ 2019-10-08 11:40 ` David Sterba
0 siblings, 0 replies; 10+ messages in thread
From: David Sterba @ 2019-10-08 11:40 UTC (permalink / raw)
To: Johannes Thumshirn
Cc: dsterba, Nikolay Borisov, David Sterba, Linux BTRFS Mailinglist
On Tue, Oct 08, 2019 at 08:47:14AM +0200, Johannes Thumshirn wrote:
> On 07/10/2019 17:46, David Sterba wrote:
> [...]
> >> nit: This function is used only once and the ARRAY_SIZE() macro is
> >> descriptive enough, why not just remove it and opencoude the call to
> >> array_size
> >
> > Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant.
>
> Nope, btrfs_csums[] is defined in ctree.c, so I can't get the size of
> this array outside of ctree.c. And it was moved to ctree.c from ctree.h
> on request by David.
Ohh, right you are of course.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 4/4] btrfs: show used checksum driver per filesystem in sysfs
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
` (2 preceding siblings ...)
2019-10-07 9:11 ` [PATCH 3/4] btrfs: sysfs: export supported checksums Johannes Thumshirn
@ 2019-10-07 9:11 ` Johannes Thumshirn
2019-10-07 14:58 ` [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Nikolay Borisov
4 siblings, 0 replies; 10+ messages in thread
From: Johannes Thumshirn @ 2019-10-07 9:11 UTC (permalink / raw)
To: David Sterba; +Cc: Linux BTRFS Mailinglist, Nikolay Borisov, Johannes Thumshirn
Show the used driver for the checksum algorithm for the filesystem in
sysfs.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
fs/btrfs/sysfs.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index aeebbdfe1a98..11a3cf7f563e 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -9,6 +9,7 @@
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/bug.h>
+#include <crypto/hash.h>
#include "ctree.h"
#include "disk-io.h"
@@ -637,6 +638,19 @@ static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
+static ssize_t btrfs_checksum_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
+
+ return snprintf(buf, PAGE_SIZE, "%s (%s)\n",
+ btrfs_super_csum_name(csum_type),
+ crypto_shash_driver_name(fs_info->csum_shash));
+}
+
+BTRFS_ATTR(, checksum, btrfs_checksum_show);
+
static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, label),
BTRFS_ATTR_PTR(, nodesize),
@@ -644,6 +658,7 @@ static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, clone_alignment),
BTRFS_ATTR_PTR(, quota_override),
BTRFS_ATTR_PTR(, metadata_uuid),
+ BTRFS_ATTR_PTR(, checksum),
NULL,
};
--
2.16.4
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
` (3 preceding siblings ...)
2019-10-07 9:11 ` [PATCH 4/4] btrfs: show used checksum driver per filesystem in sysfs Johannes Thumshirn
@ 2019-10-07 14:58 ` Nikolay Borisov
4 siblings, 0 replies; 10+ messages in thread
From: Nikolay Borisov @ 2019-10-07 14:58 UTC (permalink / raw)
To: Johannes Thumshirn, David Sterba; +Cc: Linux BTRFS Mailinglist
On 7.10.19 г. 12:11 ч., Johannes Thumshirn wrote:
> This series adds support for two additional checksum algorithms to btrfs. These
> algorithms are xxhash64[1] and sha256[2].
>
> xxhash64 is a fast non-cryptographic hash function with good collision resistance.
> It has a constant output length of 8 Byte (64 Bit), it provides a good
> trade-off between collision resistance and speed compared to the currently
> used crc32c.
>
> sha256 is the 32 Byte (256 Bit) variant of the SHA-2 cryptographic hash. It
> provides cryptographically secure collision resistance with a trade off in
> speed.
>
> Support for xxhash64 in mkfs.btrfs is in the current devel branch and sha256
> support will be sent separately after this patch-set.
>
> In addition to adding these two hash algorithms two sysfs files are
> implemented, one being /sys/fs/btrfs/features/supported_checksums showing the
> in kernel support for different checksumming algorithms. The other one is
> /sys/fs/btrfs/$FSID/checksum showing the checksum used for a specific
> file-system and the used in-kernel driver for this checksum.
>
> Here is an example in a qemu vm:
> host:/# cat /sys/fs/btrfs/features/supported_checksums
> crc32c, xxhash64, sha256
> host:/# cat /sys/fs/btrfs/3cf09516-5bb8-498f-834d-e9ec54043546/checksum
> sha256 (sha256-generic)
>
> This series has survived the usual regression testing with xfstests.
>
> I could not observe any performance differences between any of these hashes in
> my test setup 256K mixed read-write IO to a single file from a single process
> on both a 5700rpm SATA 3G Disk behind a HPE SmartArray RAID HBA and RAM Disk.
>
> Here's the raw numbers for the spinning rust behind SATA:
> CRC32C Buffered Read (KiB/s): Avg: 7881, Min: 7495, Max: 8744, Stdev: 508
> CRC32C Buffered Write (KiB/s): Avg: 7883, Min: 7497, Max: 8746, Stdev: 508
>
> CRC32C Direct Read (KiB/s): Avg: 331, Min: 319, Max: 339, Stdev: 7
> CRC32C Direct Write (KiB/s): Avg: 331, Min: 319, Max: 339, Stdev: 7
>
> XXHASH64 Buffered Read (KiB/s): Avg: 8143, Min: 7748, Max: 8721, Stdev: 355
> XXHASH64 Buffered Write (KiB/s): Avg: 8145, Min: 7750, Max: 8722, Stdev: 355
>
> XXHASH64 Direct Read (KiB/s): Avg: 311, Min: 248, Max: 336, Stdev: 36
> XXHASH64 Direct Write (KiB/s): Avg: 311, Min: 248, Max: 336, Stdev: 36
>
> SHA256 Buffered Read (KiB/s): Avg: 7997, Min: 7665, Max: 8336, Stdev: 273
> SHA256 Buffered Write (KiB/s): Avg: 7998, Min: 7666, Max: 8337, Stdev: 273
>
> SHA256 Direct Read (KiB/s): Avg: 312, Min: 248, Max: 336, Stdev: 36
> SHA256 Direct Write (KiB/s): Avg: 312, Min: 248, Max: 336, Stdev: 36
>
> The reason I could not observe any changes in performance is the fact that the
> btrfs checksumming process takes only 0.04% of the IO path. This also explains
> the very small standard deviation in the above table as I stooped benchmarking
> after 5 benchmark runs.
>
> The hottest call chain (according to perf) is this:
>
> 17.08% 0.00% kworker/u128:9- [kernel.vmlinux] [k] btrfs_finish_ordered_io
> |
> ---btrfs_finish_ordered_io
> |
> --17.04%--insert_reserved_file_extent.constprop.75
> |
> --17.02%--__btrfs_drop_extents
> |
> --16.94%--btrfs_free_extent
> |
> --16.94%--btrfs_add_delayed_data_ref
> |
> --16.90%--btrfs_qgroup_trace_extent_post
Yeah, we know qgroups tracing and backrefs resolv are somewhat slow. How
about benchmarking without them since I believe this to be more
representative of how people use btrfs.
> btrfs_find_all_roots
> |
> --16.90%--btrfs_find_all_roots_safe
> |
> --16.89%--find_parent_nodes
> |
> --16.68%--resolve_indirect_refs
> [snip]
>
> [1] https://cyan4973.github.io/xxHash
> [2] https://en.wikipedia.org/wiki/SHA-2
>
> David Sterba (1):
> btrfs: sysfs: export supported checksums
>
> Johannes Thumshirn (3):
> btrfs: add xxhash64 to checksumming algorithms
> btrfs: add sha256 to checksumming algorithms
> btrfs: show used checksum driver per filesystem in sysfs
>
> fs/btrfs/Kconfig | 2 ++
> fs/btrfs/ctree.c | 7 ++++++
> fs/btrfs/ctree.h | 2 ++
> fs/btrfs/disk-io.c | 2 ++
> fs/btrfs/super.c | 2 ++
> fs/btrfs/sysfs.c | 48 +++++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/btrfs_tree.h | 2 ++
> 7 files changed, 65 insertions(+)
>
^ permalink raw reply [flat|nested] 10+ messages in thread