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authorMiles Bader <miles@gnu.org>1997-07-21 22:39:17 +0000
committerMiles Bader <miles@gnu.org>1997-07-21 22:39:17 +0000
commite106d0f9bf3afcd2d0cd0f6d56fb202f524e578e (patch)
treee08fbe17b6f1da04efc03b7949ed7318931cd111 /libstore/map.c
parentccfa753ba17c0744c39450a2331a5540bb1e91f3 (diff)
(store_map):
If we can't map STORE directly, and it has a source file, try to map that instead.
Diffstat (limited to 'libstore/map.c')
-rw-r--r--libstore/map.c51
1 files changed, 48 insertions, 3 deletions
diff --git a/libstore/map.c b/libstore/map.c
index 4ba779ea..4ac8ce98 100644
--- a/libstore/map.c
+++ b/libstore/map.c
@@ -18,15 +18,60 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+#include <hurd.h>
+#include <hurd/io.h>
+
#include "store.h"
/* Return a memory object paging on STORE. [among other reasons,] this may
fail because store contains non-contiguous regions on the underlying
object. In such a case you can try calling some of the routines below to
get a pager. */
-error_t store_map (const struct store *store, vm_prot_t prot, mach_port_t *memobj)
+error_t store_map (const struct store *store, vm_prot_t prot,
+ mach_port_t *memobj)
{
- error_t (*map) (const struct store *store, vm_prot_t prot, mach_port_t *memobj) =
+ error_t (*map) (const struct store *store, vm_prot_t prot,
+ mach_port_t *memobj) =
store->class->map;
- return map ? (*map) (store, prot, memobj) : EOPNOTSUPP;
+ error_t err = map ? (*map) (store, prot, memobj) : EOPNOTSUPP;
+
+ if (err == EOPNOTSUPP && store->source != MACH_PORT_NULL)
+ /* Can't map the store directly, but we know it represents the file
+ STORE->source, so we can try mapping that instead. */
+ {
+ mach_port_t rd_memobj, wr_memobj;
+ int ro = (store->flags & STORE_HARD_READONLY);
+
+ if ((prot & VM_PROT_WRITE) && ro)
+ return EACCES;
+
+ err = io_map (store->port, &rd_memobj, &wr_memobj);
+ if (! err)
+ {
+ *memobj = rd_memobj;
+
+ if (!ro || wr_memobj != MACH_PORT_NULL)
+ /* If either we or the server think this object is writable, then
+ the write-memory-object must be the same as the read one (if
+ we only care about reading, then it can be null too). */
+ {
+ if (rd_memobj == wr_memobj)
+ {
+ if (rd_memobj != MACH_PORT_NULL)
+ mach_port_mod_refs (mach_task_self (), rd_memobj,
+ MACH_PORT_RIGHT_SEND, -1);
+ }
+ else
+ {
+ if (rd_memobj != MACH_PORT_NULL)
+ mach_port_deallocate (mach_task_self (), rd_memobj);
+ if (wr_memobj != MACH_PORT_NULL)
+ mach_port_deallocate (mach_task_self (), wr_memobj);
+ err = EOPNOTSUPP;
+ }
+ }
+ }
+ }
+
+ return err;
}