1 files changed, 82 insertions, 0 deletions
diff --git a/sys/fmio/fmioextnd.x b/sys/fmio/fmioextnd.x
new file mode 100644
index 00000000..0517eb93
--- /dev/null
+++ b/sys/fmio/fmioextnd.x
@@ -0,0 +1,82 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <syserr.h>
+include <mach.h>
+include "fmio.h"
+
+# FMIO_EXTEND -- Allocate new pages in the datafile.  Allocate the new pages
+# and modify the in-core page table and lfile pagemap accordingly.  The PTI is
+# not modified, allocating new pages to store the page table itself, until
+# fm_sync is called.  The page number of the first page allocated is returned
+# as the function value (a contiguous sequence of pages will be allocated).
+
+int procedure fmio_extend (fm, lfile, npages)
+
+pointer fm                      #I FMIO descriptor
+int     lfile                   #I lfile getting the new pages
+int     npages                  #I number of pages to add
+
+pointer pt, pm, lf
+int	npte_perpage, npti
+int     inc, np, p1, p2, l1, l2, i
+int	krealloc()
+
+begin
+        # Extend the global page table.
+        p1 = FM_PTNPTE(fm) + 1
+        p2 = p1 + npages - 1
+
+	# Make sure we have enough page table index entries for the new pages.
+	if (lfile != PT_LFILE) {
+	    npte_perpage = FM_SZBPAGE(fm) / (SZB_CHAR*SZ_SHORT)
+	    np = p2 + FM_PTILEN(fm)
+	    npti = (np + npte_perpage-1) / npte_perpage
+	    if (npti > FM_PTILEN(fm)) {
+		call fmio_posterr (fm, SYS_FMPTIOVFL, FM_DFNAME(fm))
+		return (ERR)
+	    }
+	}
+
+        # Increase the size of the in-core page table if necessary.
+        if (p2 > FM_PTLEN(fm)) {
+	    inc = FM_SZBPAGE(fm) / (SZ_SHORT * SZB_CHAR)
+            FM_PTLEN(fm) = ((p2 + inc-1) / inc) * inc
+            if (krealloc (FM_PTABLE(fm), FM_PTLEN(fm), TY_SHORT) == ERR)
+		return (ERR)
+        }
+
+        # Add the pages to the global page table.
+        FM_PTNPTE(fm) = p2
+        pt = FM_PTABLE(fm)
+        do i = p1, p2
+            Mems[pt+i-1] = lfile
+
+        lf = FM_FTABLE(fm) + lfile * LEN_FTE
+        pm = LF_PAGEMAP(lf)
+
+        # Extend the lfile page table if the lfile is active.
+        if (pm != NULL) {
+            l1 = LF_NPAGES(lf) + 1
+            l2 = l1 + npages - 1
+
+            # Increase the size of the lfile pagemap if necessary.
+            if (l2 > LF_PMLEN(lf)) {
+                LF_PMLEN(lf) = (l2 + INC_PMLEN-1) / INC_PMLEN * INC_PMLEN
+                if (krealloc (LF_PAGEMAP(lf), LF_PMLEN(lf), TY_INT) == ERR)
+		    return (ERR)
+                pm = LF_PAGEMAP(lf)
+            }
+
+            # Add the pages to the lfile page table.
+            LF_NPAGES(lf) = l2
+            do i = l1, l2
+                Memi[pm+i-1] = p1 + i - l1
+        }
+
+	# Update the FTE for lfile zero (the page table file).
+	lf = FM_FTABLE(fm)
+	LF_FSIZE(lf) = FM_PTNPTE(fm) * SZ_SHORT * SZB_CHAR
+
+        FM_DHMODIFIED(fm) = YES
+        return (p1)
+end