[Xen-changelog] [xen-unstable] libxl: separate forced and non-forced device remove.

[Xen patchbot-unstable <patchbot@xxxxxxx>]

# HG changeset patch
# User Ian Campbell <ian.campbell@xxxxxxxxxx>
# Date 1318941402 -3600
# Node ID 18505ddad997630e6696089c6fc6fe2b0e35014a
# Parent  90b21171c8c0e25ff7d1648dcd55c7e806b88e11
libxl: separate forced and non-forced device remove.

The function libxl__device_destroy currently takes a force parameter however:

  * in the forced case we initiate a graceful shutdown and then
    immediately nuke the backend directory, quite likely before anyone
    got a chance to react.

  * the callers all have a "wait" variable and pass in "!wait" as the
    force argument which is confusing since not waiting is not really
    the same thing as forcing the destroy.

Therefore split the function into libxl__device_remove and
libxl__device_destroy. The former initiates a graceful shutdown which
the latter simply nukes the backend directory.

This makes some of the callers look a bit odd but that should fall out as I
continue to pull this piece of string.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
---


diff -r 90b21171c8c0 -r 18505ddad997 tools/libxl/libxl_device.c
--- a/tools/libxl/libxl_device.c        Tue Oct 18 13:36:42 2011 +0100
+++ b/tools/libxl/libxl_device.c        Tue Oct 18 13:36:42 2011 +0100
@@ -365,7 +365,7 @@
     return -1;
 }
 
-int libxl__device_destroy(libxl__gc *gc, char *be_path, int force)
+int libxl__device_remove(libxl__gc *gc, char *be_path)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
     xs_transaction_t t;
@@ -393,17 +393,22 @@
             goto out;
         }
     }
-    if (!force) {
-        xs_watch(ctx->xsh, state_path, be_path);
-        rc = 1;
-    } else {
-        xs_rm(ctx->xsh, XBT_NULL, be_path);
-    }
+
+    xs_watch(ctx->xsh, state_path, be_path);
     libxl__device_destroy_tapdisk(gc, be_path);
+    rc = 1;
 out:
     return rc;
 }
 
+int libxl__device_destroy(libxl__gc *gc, char *be_path)
+{
+    libxl_ctx *ctx = libxl__gc_owner(gc);
+    xs_rm(ctx->xsh, XBT_NULL, be_path);
+    libxl__device_destroy_tapdisk(gc, be_path);
+    return 0;
+}
+
 static int wait_for_dev_destroy(libxl__gc *gc, struct timeval *tv)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
@@ -461,7 +466,9 @@
             fe_path = libxl__sprintf(gc, "/local/domain/%d/device/%s/%s", 
domid, l1[i], l2[j]);
             be_path = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, 
"%s/backend", fe_path));
             if (be_path != NULL) {
-                if (libxl__device_destroy(gc, be_path, force) > 0)
+                int rc = force ? libxl__device_destroy(gc, be_path)
+                               : libxl__device_remove(gc, be_path);
+                if (rc > 0)
                     n_watches++;
             } else {
                 xs_rm(ctx->xsh, XBT_NULL, path);
@@ -473,7 +480,9 @@
     fe_path = libxl__sprintf(gc, "/local/domain/%d/console", domid);
     be_path = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/backend", 
fe_path));
     if (be_path && strcmp(be_path, "")) {
-        if (libxl__device_destroy(gc, be_path, force) > 0)
+        int rc = force ? libxl__device_destroy(gc, be_path)
+                       : libxl__device_remove(gc, be_path);
+        if (rc > 0)
             n_watches++;
     }
 
@@ -506,7 +515,10 @@
 
     backend_path = libxl__device_backend_path(gc, dev);
 
-    rc = libxl__device_destroy(gc, backend_path, !wait);
+    if (wait)
+        rc = libxl__device_remove(gc, backend_path);
+    else
+        rc = libxl__device_destroy(gc, backend_path);
     if (rc == -1) {
         rc = ERROR_FAIL;
         goto out;
diff -r 90b21171c8c0 -r 18505ddad997 tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h      Tue Oct 18 13:36:42 2011 +0100
+++ b/tools/libxl/libxl_internal.h      Tue Oct 18 13:36:42 2011 +0100
@@ -253,7 +253,8 @@
 _hidden char *libxl__device_backend_path(libxl__gc *gc, libxl__device *device);
 _hidden char *libxl__device_frontend_path(libxl__gc *gc, libxl__device 
*device);
 _hidden int libxl__device_del(libxl__gc *gc, libxl__device *dev, int wait);
-_hidden int libxl__device_destroy(libxl__gc *gc, char *be_path, int force);
+_hidden int libxl__device_remove(libxl__gc *gc, char *be_path);
+_hidden int libxl__device_destroy(libxl__gc *gc, char *be_path);
 _hidden int libxl__devices_destroy(libxl__gc *gc, uint32_t domid, int force);
 _hidden int libxl__wait_for_backend(libxl__gc *gc, char *be_path, char *state);
 
diff -r 90b21171c8c0 -r 18505ddad997 tools/libxl/libxl_pci.c
--- a/tools/libxl/libxl_pci.c   Tue Oct 18 13:36:42 2011 +0100
+++ b/tools/libxl/libxl_pci.c   Tue Oct 18 13:36:42 2011 +0100
@@ -411,8 +411,7 @@
 
     if (num == 1) {
         char *fe_path = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, 
"%s/frontend", be_path));
-        libxl__device_destroy(gc, be_path, 1);
-        xs_rm(ctx->xsh, XBT_NULL, be_path);
+        libxl__device_destroy(gc, be_path);
         xs_rm(ctx->xsh, XBT_NULL, fe_path);
         return 0;
     }

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