[PATCH 01/13] md/raid6: move raid6 data processing to raid6_pq.ko

From: Dan Williams
Date: Wed Mar 18 2009 - 15:20:57 EST


Move the raid6 data processing routines into a standalone module
(raid6_pq) to prepare them to be called from async_tx wrappers and other
non-md drivers/modules. This precludes a circular dependency of raid456
needing the async modules for data processing while those modules in
turn depend on raid456 for the base level synchronous raid6 routines.

To support this move:
1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h
2/ The raid6_call, recovery calls, and table symbols are exported
3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to
compile

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/md/Kconfig | 4 ++++
drivers/md/Makefile | 4 +++-
drivers/md/mktables.c | 14 +++++++++++++-
drivers/md/raid5.c | 12 +-----------
drivers/md/raid5.h | 2 ++
drivers/md/raid6algos.c | 21 ++++++++++++++++++++-
drivers/md/raid6altivec.uc | 2 +-
drivers/md/raid6int.uc | 2 +-
drivers/md/raid6mmx.c | 2 +-
drivers/md/raid6recov.c | 8 +++++---
drivers/md/raid6sse1.c | 2 +-
drivers/md/raid6sse2.c | 2 +-
drivers/md/raid6test/Makefile | 2 +-
drivers/md/raid6test/test.c | 2 +-
include/linux/raid/pq.h | 3 ---
15 files changed, 55 insertions(+), 27 deletions(-)
rename drivers/md/raid6.h => include/linux/raid/pq.h (97%)

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 2281b50..449d0b9 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -121,6 +121,7 @@ config MD_RAID10
config MD_RAID456
tristate "RAID-4/RAID-5/RAID-6 mode"
depends on BLK_DEV_MD
+ select MD_RAID6_PQ
select ASYNC_MEMCPY
select ASYNC_XOR
---help---
@@ -180,6 +181,9 @@ config MD_RAID5_RESHAPE

If unsure, say Y.

+config MD_RAID6_PQ
+ tristate
+
config MD_MULTIPATH
tristate "Multipath I/O support"
depends on BLK_DEV_MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 3b118da..45cc595 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -9,7 +9,8 @@ dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \
dm-snap-persistent.o
dm-mirror-y += dm-raid1.o
md-mod-y += md.o bitmap.o
-raid456-y += raid5.o raid6algos.o raid6recov.o raid6tables.o \
+raid456-y += raid5.o
+raid6_pq-y += raid6algos.o raid6recov.o raid6tables.o \
raid6int1.o raid6int2.o raid6int4.o \
raid6int8.o raid6int16.o raid6int32.o \
raid6altivec1.o raid6altivec2.o raid6altivec4.o \
@@ -26,6 +27,7 @@ obj-$(CONFIG_MD_LINEAR) += linear.o
obj-$(CONFIG_MD_RAID0) += raid0.o
obj-$(CONFIG_MD_RAID1) += raid1.o
obj-$(CONFIG_MD_RAID10) += raid10.o
+obj-$(CONFIG_MD_RAID6_PQ) += raid6_pq.o
obj-$(CONFIG_MD_RAID456) += raid456.o
obj-$(CONFIG_MD_MULTIPATH) += multipath.o
obj-$(CONFIG_MD_FAULTY) += faulty.o
diff --git a/drivers/md/mktables.c b/drivers/md/mktables.c
index b61d576..3b15008 100644
--- a/drivers/md/mktables.c
+++ b/drivers/md/mktables.c
@@ -59,7 +59,7 @@ int main(int argc, char *argv[])
uint8_t v;
uint8_t exptbl[256], invtbl[256];

- printf("#include \"raid6.h\"\n");
+ printf("#include <linux/raid/pq.h>\n");

/* Compute multiplication table */
printf("\nconst u8 __attribute__((aligned(256)))\n"
@@ -76,6 +76,9 @@ int main(int argc, char *argv[])
printf("\t},\n");
}
printf("};\n");
+ printf("#ifdef __KERNEL__\n");
+ printf("EXPORT_SYMBOL(raid6_gfmul);\n");
+ printf("#endif\n");

/* Compute power-of-2 table (exponent) */
v = 1;
@@ -92,6 +95,9 @@ int main(int argc, char *argv[])
}
}
printf("};\n");
+ printf("#ifdef __KERNEL__\n");
+ printf("EXPORT_SYMBOL(raid6_gfexp);\n");
+ printf("#endif\n");

/* Compute inverse table x^-1 == x^254 */
printf("\nconst u8 __attribute__((aligned(256)))\n"
@@ -104,6 +110,9 @@ int main(int argc, char *argv[])
}
}
printf("};\n");
+ printf("#ifdef __KERNEL__\n");
+ printf("EXPORT_SYMBOL(raid6_gfinv);\n");
+ printf("#endif\n");

/* Compute inv(2^x + 1) (exponent-xor-inverse) table */
printf("\nconst u8 __attribute__((aligned(256)))\n"
@@ -115,6 +124,9 @@ int main(int argc, char *argv[])
(j == 7) ? '\n' : ' ');
}
printf("};\n");
+ printf("#ifdef __KERNEL__\n");
+ printf("EXPORT_SYMBOL(raid6_gfexi);\n");
+ printf("#endif\n");

return 0;
}
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 70b50af..21626cc 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -45,11 +45,11 @@

#include <linux/blkdev.h>
#include <linux/kthread.h>
+#include <linux/raid/pq.h>
#include <linux/async_tx.h>
#include <linux/seq_file.h>
#include "md.h"
#include "raid5.h"
-#include "raid6.h"
#include "bitmap.h"

/*
@@ -94,11 +94,6 @@

#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))

-#if !RAID6_USE_EMPTY_ZERO_PAGE
-/* In .bss so it's zeroed */
-const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
-#endif
-
/*
* We maintain a biased count of active stripes in the bottom 16 bits of
* bi_phys_segments, and a count of processed stripes in the upper 16 bits
@@ -5131,11 +5126,6 @@ static struct mdk_personality raid4_personality =

static int __init raid5_init(void)
{
- int e;
-
- e = raid6_select_algo();
- if ( e )
- return e;
register_md_personality(&raid6_personality);
register_md_personality(&raid5_personality);
register_md_personality(&raid4_personality);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index c172371..2934ee0 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -269,6 +269,8 @@ struct r6_state {
#define READ_MODIFY_WRITE 2
/* not a write method, but a compute_parity mode */
#define CHECK_PARITY 3
+/* Additional compute_parity mode -- updates the parity w/o LOCKING */
+#define UPDATE_PARITY 4

/*
* Stripe state
diff --git a/drivers/md/raid6algos.c b/drivers/md/raid6algos.c
index 1f6a3c8..34e57ff 100644
--- a/drivers/md/raid6algos.c
+++ b/drivers/md/raid6algos.c
@@ -16,10 +16,16 @@
* Algorithm list and algorithm selection for RAID-6
*/

-#include "raid6.h"
+#include <linux/raid/pq.h>
#ifndef __KERNEL__
#include <sys/mman.h>
#include <stdio.h>
+#else
+#if !RAID6_USE_EMPTY_ZERO_PAGE
+/* In .bss so it's zeroed */
+const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
+EXPORT_SYMBOL(raid6_empty_zero_page);
+#endif
#endif

struct raid6_calls raid6_call;
@@ -79,6 +85,7 @@ const struct raid6_calls * const raid6_algos[] = {
#else
/* Need more time to be stable in userspace */
#define RAID6_TIME_JIFFIES_LG2 9
+#define time_before(x, y) ((x) < (y))
#endif

/* Try to pick the best algorithm */
@@ -152,3 +159,15 @@ int __init raid6_select_algo(void)

return best ? 0 : -EINVAL;
}
+
+static void raid6_exit(void)
+{
+ do { } while (0);
+}
+
+#ifdef __KERNEL__
+EXPORT_SYMBOL_GPL(raid6_call);
+subsys_initcall(raid6_select_algo);
+module_exit(raid6_exit);
+MODULE_LICENSE("GPL");
+#endif
diff --git a/drivers/md/raid6altivec.uc b/drivers/md/raid6altivec.uc
index 2175806..699dfee 100644
--- a/drivers/md/raid6altivec.uc
+++ b/drivers/md/raid6altivec.uc
@@ -22,7 +22,7 @@
* bracked this with preempt_disable/enable or in a lock)
*/

-#include "raid6.h"
+#include <linux/raid/pq.h>

#ifdef CONFIG_ALTIVEC

diff --git a/drivers/md/raid6int.uc b/drivers/md/raid6int.uc
index 32a0bac..f9bf9cb 100644
--- a/drivers/md/raid6int.uc
+++ b/drivers/md/raid6int.uc
@@ -18,7 +18,7 @@
* This file is postprocessed using unroll.pl
*/

-#include "raid6.h"
+#include <linux/raid/pq.h>

/*
* This is the C data type to use
diff --git a/drivers/md/raid6mmx.c b/drivers/md/raid6mmx.c
index 804cb50..e7f6c13 100644
--- a/drivers/md/raid6mmx.c
+++ b/drivers/md/raid6mmx.c
@@ -18,7 +18,7 @@

#if defined(__i386__) && !defined(__arch_um__)

-#include "raid6.h"
+#include <linux/raid/pq.h>
#include "raid6x86.h"

/* Shared with raid6sse1.c */
diff --git a/drivers/md/raid6recov.c b/drivers/md/raid6recov.c
index 7a98b86..844d27d 100644
--- a/drivers/md/raid6recov.c
+++ b/drivers/md/raid6recov.c
@@ -18,7 +18,7 @@
* the syndrome.)
*/

-#include "raid6.h"
+#include <linux/raid/pq.h>

/* Recover two failed data blocks. */
void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
@@ -98,8 +98,10 @@ void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs)
}
}

-
-#ifndef __KERNEL__ /* Testing only */
+#ifdef __KERNEL__
+EXPORT_SYMBOL_GPL(raid6_2data_recov);
+EXPORT_SYMBOL_GPL(raid6_datap_recov);
+#else /* Testing only */

/* Recover two failed blocks. */
void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs)
diff --git a/drivers/md/raid6sse1.c b/drivers/md/raid6sse1.c
index 15c5889..b274dd5 100644
--- a/drivers/md/raid6sse1.c
+++ b/drivers/md/raid6sse1.c
@@ -23,7 +23,7 @@

#if defined(__i386__) && !defined(__arch_um__)

-#include "raid6.h"
+#include <linux/raid/pq.h>
#include "raid6x86.h"

/* Defined in raid6mmx.c */
diff --git a/drivers/md/raid6sse2.c b/drivers/md/raid6sse2.c
index 2e92e96..6ed6c6c 100644
--- a/drivers/md/raid6sse2.c
+++ b/drivers/md/raid6sse2.c
@@ -19,7 +19,7 @@

#if (defined(__i386__) || defined(__x86_64__)) && !defined(__arch_um__)

-#include "raid6.h"
+#include <linux/raid/pq.h>
#include "raid6x86.h"

static const struct raid6_sse_constants {
diff --git a/drivers/md/raid6test/Makefile b/drivers/md/raid6test/Makefile
index 78e0396..58ffdf4 100644
--- a/drivers/md/raid6test/Makefile
+++ b/drivers/md/raid6test/Makefile
@@ -5,7 +5,7 @@

CC = gcc
OPTFLAGS = -O2 # Adjust as desired
-CFLAGS = -I.. -g $(OPTFLAGS)
+CFLAGS = -I.. -I ../../../include -g $(OPTFLAGS)
LD = ld
PERL = perl
AR = ar
diff --git a/drivers/md/raid6test/test.c b/drivers/md/raid6test/test.c
index 559cc41..7a93031 100644
--- a/drivers/md/raid6test/test.c
+++ b/drivers/md/raid6test/test.c
@@ -17,7 +17,7 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
-#include "raid6.h"
+#include <linux/raid/pq.h>

#define NDISKS 16 /* Including P and Q */

diff --git a/drivers/md/raid6.h b/include/linux/raid/pq.h
similarity index 97%
rename from drivers/md/raid6.h
rename to include/linux/raid/pq.h
index 8a9c823..a019670 100644
--- a/drivers/md/raid6.h
+++ b/include/linux/raid/pq.h
@@ -19,9 +19,6 @@
#define RAID6_USE_EMPTY_ZERO_PAGE 0
#include <linux/blkdev.h>

-/* Additional compute_parity mode -- updates the parity w/o LOCKING */
-#define UPDATE_PARITY 4
-
/* We need a pre-zeroed page... if we don't want to use the kernel-provided
one define it here */
#if RAID6_USE_EMPTY_ZERO_PAGE

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