From 34b3e6c92af1fa3f7067e4fa05ffa9d8bd41c96c Mon Sep 17 00:00:00 2001 From: Feifei Xu Date: Wed, 1 Jun 2016 19:18:30 +0800 Subject: [PATCH] Btrfs: self-tests: Fix extent buffer bitmap test fail on BE system In __test_eb_bitmaps(), we write random data to a bitmap. Then copy the bitmap to another bitmap that resides inside an extent buffer. Later we verify the values of corresponding bits in the bitmap and the bitmap inside the extent buffer. However, extent_buffer_test_bit() reads in byte granularity while test_bit() reads in unsigned long granularity. Hence we end up comparing wrong bits on big-endian systems such as ppc64. This commit fixes the issue by reading the bitmap in byte granularity. Reviewed-by: Josef Bacik Reviewed-by: Chandan Rajendra Signed-off-by: Feifei Xu Signed-off-by: David Sterba --- fs/btrfs/tests/extent-io-tests.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c index 2794fed71fa4..d19ab0317283 100644 --- a/fs/btrfs/tests/extent-io-tests.c +++ b/fs/btrfs/tests/extent-io-tests.c @@ -273,6 +273,16 @@ out: return ret; } +/** + * test_bit_in_byte - Determine whether a bit is set in a byte + * @nr: bit number to test + * @addr: Address to start counting from + */ +static inline int test_bit_in_byte(int nr, const u8 *addr) +{ + return 1UL & (addr[nr / BITS_PER_BYTE] >> (nr & (BITS_PER_BYTE - 1))); +} + static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb, unsigned long len) { @@ -338,7 +348,7 @@ static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb, for (i = 0; i < len * BITS_PER_BYTE; i++) { int bit, bit1; - bit = !!test_bit(i, bitmap); + bit = !!test_bit_in_byte(i, (u8 *)bitmap); bit1 = !!extent_buffer_test_bit(eb, 0, i); if (bit1 != bit) { test_msg("Testing bit pattern failed\n"); -- 2.20.1