On Tue, 2007-10-16 at 20:32 +0800, Yan Zheng wrote: > Hello > > Some xxx_extent_buffer functions have codes like: > -- > offset = dst_offset & ((unsigned long)PAGE_CACHE_SIZE - 1); > if (i == 0) > offset += start_offset; > > I can't understand why these is a test. I feel the variable 'offset' > should be computed by code like: > -- > offset = (dst_offset + start_offset) & ((unsigned > long)PAGE_CACHE_SIZE - 1);
It could be offset = (dst->start + dst_offset) & PAGE_CACHE_SIZE - 1, but start_offset is already the offset into the first page. So, we only want to add it on the first page. -chris _______________________________________________ Btrfs-devel mailing list [email protected] http://oss.oracle.com/mailman/listinfo/btrfs-devel
