bsd/vfs/vfs_journal.c

950 	off_t	overlap, block_start, block_end;
956 	// first, eliminate any overlap with the previous entry
960 		overlap = prev_block_end - block_start;
961 		if (overlap > 0) {
962 			if (overlap % jhdr_size != 0) {
963 				panic("jnl: do_overlap: overlap with previous entry not a multiple of %zd\n", jhdr_size);
975 					panic("jnl: do_overlap: error inserting during pre-overlap\n");
979 			// Regardless, we need to truncate the previous entry to the beginning of the overlap
985 	// then, bail out fast if there's no overlap with the entries that follow
987 		return 0; // no overlap, no overwrite
994 	// Otherwise, find all cases of total and partial overlap. We use the special
1005 			overlap = block_end - (*buf_ptr)[index].block_num*jhdr_size;
1006 			if (overlap > 0) {
1007 				if (overlap % jhdr_size != 0) {
1008 					panic("jnl: do_overlap: overlap of %lld is not multiple of %zd\n", overlap, jhdr_size);
1011 				// if we partially overlap this entry, adjust its block number, jnl offset, and size
1012 				(*buf_ptr)[index].block_num += (overlap / jhdr_size); // make sure overlap is multiple of jhdr_size, or round up
1015 				new_offset = (*buf_ptr)[index].jnl_offset + overlap; // check for wrap-around
1021 				(*buf_ptr)[index].block_size -= overlap; // sanity check for negative value
1023 					panic("jnl: do_overlap: after overlap, new block size is invalid (%u)\n", (*buf_ptr)[index].block_size);
1079 	// Determine whether we're overwriting an existing entry by checking for overlap
3042  ;				overlap the given extent.
3050  ;	(result)	- TRUE if one or more extents overlap, FALSE otherwise.
3138 	 * that overlap or are contiguous with the input extent.
3252 	 * extent.  These extents will be modified if they overlap the input
3398 		 * See if a pending trim has any extents that overlap with the
3408 			 * There was an overlap, so avoid trimming the extent we
3648 	 * next transaction group which may overlap the current journal flush...
3680 		 * unlock_condition... we can overlap the preparation of