[Xen-changelog] [xen master] libxl: Fix libxl_set_memory_target return value

[patchbot@xxxxxxx]

commit ecdc6fd8787b9e01e53d85e995ce8a495d8d93a5
Author:     George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
AuthorDate: Mon May 9 13:30:55 2016 +0200
Commit:     Wei Liu <wei.liu2@xxxxxxxxxx>
CommitDate: Thu Jun 9 16:31:56 2016 +0100

    libxl: Fix libxl_set_memory_target return value
    
    libxl_set_memory_target seems to have the following return values:
    
     '1' : on failure, if the failure happens because of a xenstore error
           *or* invalid target
     '-1': on error, the setmaxmem and set_pod_target hypercalls
           return -1 and set errno appropriately.
     '0' : on success
    
    Make it consistently return ERROR_FAIL on failure, unless the
    parameters were invalid, in which case return ERROR_INVAL.
    
    In accordance with CODING_SYTLE:
    
      1. Leave rc uninitialized, and set when an error is detected
    
      2. Use 'r' for return values to functions whose return values are a
         different error space (like xc_domain_setmaxmem and
         xc_domain_set_pod_target)
    
      3. Use 'lrc' for return values to local functions libxl__*
         where a failure means retry, rather than fail the whole function
         (libxl__fill_dom0_memory_info), to reduce the risk of that.
    
    Signed-off-by: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
    Signed-off-by: Paulina Szubarczyk <paulinaszubarczyk@xxxxxxxxx>
    Reviewed-by: Olaf Hering <olaf@xxxxxxxxx>
    Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 tools/libxl/libxl.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 7584966..9afc4cd 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -4901,7 +4901,7 @@ int libxl_set_memory_target(libxl_ctx *ctx, uint32_t 
domid,
         int32_t target_memkb, int relative, int enforce)
 {
     GC_INIT(ctx);
-    int rc = 1, abort_transaction = 0;
+    int rc, r, lrc, abort_transaction = 0;
     uint64_t memorykb;
     uint32_t videoram = 0;
     uint32_t current_target_memkb = 0, new_target_memkb = 0;
@@ -4929,15 +4929,15 @@ retry_transaction:
     if (!target && !domid) {
         if (!xs_transaction_end(ctx->xsh, t, 1))
             goto out_no_transaction;
-        rc = libxl__fill_dom0_memory_info(gc, &current_target_memkb,
+        lrc = libxl__fill_dom0_memory_info(gc, &current_target_memkb,
                                           &current_max_memkb);
-        if (rc < 0)
-            goto out_no_transaction;
+        if (lrc < 0) { rc = ERROR_FAIL; goto out_no_transaction; }
         goto retry_transaction;
     } else if (!target) {
         LOGE(ERROR, "cannot get target memory info from %s/memory/target",
              dompath);
         abort_transaction = 1;
+        rc = ERROR_FAIL;
         goto out;
     } else {
         current_target_memkb = strtoul(target, &endptr, 10);
@@ -4945,6 +4945,7 @@ retry_transaction:
             LOGE(ERROR, "invalid memory target %s from %s/memory/target\n",
                  target, dompath);
             abort_transaction = 1;
+            rc = ERROR_FAIL;
             goto out;
         }
     }
@@ -4953,6 +4954,7 @@ retry_transaction:
         LOGE(ERROR, "cannot get memory info from %s/memory/static-max",
              dompath);
         abort_transaction = 1;
+        rc = ERROR_FAIL;
         goto out;
     }
     memorykb = strtoul(memmax, &endptr, 10);
@@ -4960,6 +4962,7 @@ retry_transaction:
         LOGE(ERROR, "invalid max memory %s from %s/memory/static-max\n",
              memmax, dompath);
         abort_transaction = 1;
+        rc = ERROR_FAIL;
         goto out;
     }
 
@@ -4979,6 +4982,7 @@ retry_transaction:
             "memory_dynamic_max must be less than or equal to"
             " memory_static_max\n");
         abort_transaction = 1;
+        rc = ERROR_INVAL;
         goto out;
     }
 
@@ -4986,33 +4990,36 @@ retry_transaction:
         LOG(ERROR, "new target %d for dom0 is below the minimum threshold",
             new_target_memkb);
         abort_transaction = 1;
+        rc = ERROR_INVAL;
         goto out;
     }
 
     if (enforce) {
         memorykb = new_target_memkb + videoram;
-        rc = xc_domain_setmaxmem(ctx->xch, domid, memorykb +
+        r = xc_domain_setmaxmem(ctx->xch, domid, memorykb +
                 LIBXL_MAXMEM_CONSTANT);
-        if (rc != 0) {
+        if (r != 0) {
             LOGE(ERROR,
                  "xc_domain_setmaxmem domid=%u memkb=%"PRIu64" failed 
""rc=%d\n",
                  domid,
                  memorykb + LIBXL_MAXMEM_CONSTANT,
-                 rc);
+                 r);
             abort_transaction = 1;
+            rc = ERROR_FAIL;
             goto out;
         }
     }
 
-    rc = xc_domain_set_pod_target(ctx->xch, domid,
+    r = xc_domain_set_pod_target(ctx->xch, domid,
             (new_target_memkb + LIBXL_MAXMEM_CONSTANT) / 4, NULL, NULL, NULL);
-    if (rc != 0) {
+    if (r != 0) {
         LOGE(ERROR,
              "xc_domain_set_pod_target domid=%d, memkb=%d ""failed rc=%d\n",
              domid,
              new_target_memkb / 4,
-             rc);
+             r);
         abort_transaction = 1;
+        rc = ERROR_FAIL;
         goto out;
     }
 
@@ -5026,6 +5033,7 @@ retry_transaction:
                      "%"PRIu32, new_target_memkb / 1024);
     libxl_dominfo_dispose(&ptr);
 
+    rc = 0;
 out:
     if (!xs_transaction_end(ctx->xsh, t, abort_transaction)
         && !abort_transaction)
--
generated by git-patchbot for /home/xen/git/xen.git#master

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