| Message ID | 201605270701.u4R6xUai016007@mx0a-001b2d01.pphosted.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, May 27, 2016 at 03:00:38PM +0800, Feifei Xu wrote: > 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: Chandan Rajendra <chandan@linux.vnet.ibm.com> > Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> > --- > 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 b06b13a..d33f28f 100644 > --- a/fs/btrfs/tests/extent-io-tests.c > +++ b/fs/btrfs/tests/extent-io-tests.c > @@ -275,6 +275,16 @@ 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))); minor nit: return 1UL & (addr[nr / BITS_PER_BYTE] >> (nr & (BITS_PER_BYTE - 1))); otherwise looks ok. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c index b06b13a..d33f28f 100644 --- a/fs/btrfs/tests/extent-io-tests.c +++ b/fs/btrfs/tests/extent-io-tests.c @@ -275,6 +275,16 @@ 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) { @@ -339,7 +349,7 @@ 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");