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authorDavid Sterba <dsterba@suse.com>2016-07-28 19:56:20 +0200
committerDavid Sterba <dsterba@suse.com>2016-07-29 15:04:54 +0200
commitaf1812090bf957cdbc3d2e49e3a2d68b2108a07d (patch)
treeda1b08f10df6b426e9bc9cd81009740d51b42390 /raid6.c
parent4e4c1e603970a47cc8088d23657a85f2602feef6 (diff)
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btrfs-progs: fix unaligned access in raid6 calculations
The raid6 code matches kernel implementation that also does the unaligned access. So to keep the code close, add helpers for unaligned native access and use them. The helpers are local as we don't plan to use them elsewhere. Reported-by: Anatoly Pugachev <matorola@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'raid6.c')
-rw-r--r--raid6.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/raid6.c b/raid6.c
index a6ee483..833df5f 100644
--- a/raid6.c
+++ b/raid6.c
@@ -11,6 +11,10 @@
* ----------------------------------------------------------------------- */
/*
+ * Added helpers for unaligned native int access
+ */
+
+/*
* raid6int1.c
*
* 1-way unrolled portable integer math RAID-6 instruction set
@@ -33,11 +37,15 @@
# define NSIZE 8
# define NSHIFT 3
typedef uint64_t unative_t;
+#define put_unaligned_native(val,p) put_unaligned_64((val),(p))
+#define get_unaligned_native(p) get_unaligned_64((p))
#else
# define NBYTES(x) ((x) * 0x01010101U)
# define NSIZE 4
# define NSHIFT 2
typedef uint32_t unative_t;
+#define put_unaligned_native(val,p) put_unaligned_32((val),(p))
+#define get_unaligned_native(p) get_unaligned_32((p))
#endif
/*
@@ -84,9 +92,9 @@ void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs)
q = dptr[z0+2]; /* RS syndrome */
for ( d = 0 ; d < bytes ; d += NSIZE*1 ) {
- wq0 = wp0 = *(unative_t *)&dptr[z0][d+0*NSIZE];
+ wq0 = wp0 = get_unaligned_native(&dptr[z0][d+0*NSIZE]);
for ( z = z0-1 ; z >= 0 ; z-- ) {
- wd0 = *(unative_t *)&dptr[z][d+0*NSIZE];
+ wd0 = get_unaligned_native(&dptr[z][d+0*NSIZE]);
wp0 ^= wd0;
w20 = MASK(wq0);
w10 = SHLBYTE(wq0);
@@ -94,8 +102,8 @@ void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs)
w10 ^= w20;
wq0 = w10 ^ wd0;
}
- *(unative_t *)&p[d+NSIZE*0] = wp0;
- *(unative_t *)&q[d+NSIZE*0] = wq0;
+ put_unaligned_native(wp0, &p[d+NSIZE*0]);
+ put_unaligned_native(wq0, &q[d+NSIZE*0]);
}
}