[patch] remap tries hard to map

[Neal H Walfield]

If store_remap sees that there is a class specific function to remap the
underlying store, it will use this.  If, however, this fails, for any
reason, store_remap just gives up.  This is wrong; the class specific
remap functions can often only handle corner cases (e.g. the device
class can only map a contiguous region starting at offset zero), yet
store_remap can itself set up a pager.  This patch corrects this
deficiency.  Here is a change log:

libstore/ChangeLog

2001-08-12  Neal H Walfield  <neal@cs.uml.edu>

        * remap.c: Include <errno.h>, <alloca.h> and <sys/types.h>.
        (store_remap): If the class specific remap function fails, try
        to remap the store ourselves.

        (remap_open): Fix formatting error.


Index: remap.c
===================================================================
RCS file: /cvs/hurd/libstore/remap.c,v
retrieving revision 1.10
diff -u -p -r1.10 remap.c
--- remap.c     2001/03/07 15:01:37     1.10
+++ remap.c     2001/08/15 08:51:07
@@ -21,6 +21,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <errno.h>
+#include <alloca.h>
+#include <sys/types.h>
 #include <hurd/fs.h>
 
 #include "store.h"
@@ -135,7 +138,8 @@ remap_open (const char *name, int flags,
       p = endp;
       if (*p == ',')
        ++p;
-    } while (p < end);
+    }
+  while (p < end);
 
   err = store_typed_open (end + 1, flags, classes, &from);
   if (!err)
@@ -309,30 +313,33 @@ store_remap (struct store *source,
             const struct store_run *runs, size_t num_runs,
             struct store **store)
 {
+  error_t err;
+  struct store_run *xruns = 0;
+  size_t num_xruns = 0;
+
   if (source->class->remap)
-    /* Use the class-specific remaping function.  */
-    return (* source->class->remap) (source, runs, num_runs, store);
-  else
-    /* Just replace SOURCE's runs-list by an appropiately translated RUNS. */
+    /* The the class-specific remaping function.  */
     {
-      struct store_run *xruns = 0;
-      size_t num_xruns = 0;
-      error_t err =
-       store_remap_runs (runs, num_runs, source->runs, source->num_runs,
-                         &xruns, &num_xruns);
+      err = (* source->class->remap) (source, runs, num_runs, store);
       if (! err)
-       {
-         /* Don't use store_set_runs -- we've already allocated the
-            storage. */
-         free (source->runs);
-         source->runs = xruns;
-         source->num_runs = num_xruns;
-         source->flags &= ~STORE_ENFORCED;
-         source->end = 0;      /* Needed to make _store_derive work.  */
-         store_close_source (source);
-         _store_derive (source);
-         *store = source;
-       }
-      return err;
+       return 0;
     }
+
+  /* Just replace SOURCE's runs-list by an appropiately translated RUNS. */
+  err = store_remap_runs (runs, num_runs, source->runs, source->num_runs,
+                         &xruns, &num_xruns);
+  if (! err)
+    {
+      /* Don't use store_set_runs -- we've already allocated the storage. */
+      free (source->runs);
+      source->runs = xruns;
+      source->num_runs = num_xruns;
+      source->flags &= ~STORE_ENFORCED;
+      source->end = 0; /* Needed to make _store_derive work.  */
+      store_close_source (source);
+      _store_derive (source);
+      *store = source;
+    }
+
+  return err;
 }

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