xm dump-core command add on (TAKE 4)

diff -r 11626efd003c -r 0c43a1f62c85 tools/libxc/xc_core.c
@@ -5,6 +5,12 @@
 /* number of pages to write at a time */
 #define DUMP_INCREMENT (4 * 1024)
 #define round_pgup(_p)    (((_p)+(PAGE_SIZE-1))&PAGE_MASK)
+
+/* Callback args for writing to a local dump file. */
+struct dump_args {
+    int     fd;
+    int     incomp_fd;
+};
 
 static int
 copy_from_domain_page(int xc_handle,

@@ -27,7 +33,7 @@ xc_domain_dumpcore_via_callback(int xc_h
                                 void *args,
                                 dumpcore_rtn_t dump_rtn)
 {
-    unsigned long nr_pages;
+    unsigned long n, nr_pages;
     xen_pfn_t *page_array = NULL;
     xc_dominfo_t info;
     int i, nr_vcpus = 0;

@@ -37,6 +43,12 @@ xc_domain_dumpcore_via_callback(int xc_h
     char dummy[PAGE_SIZE];
     int dummy_len;
     int sts;
+    unsigned int cpy_err_cnt = 0;
+    struct dump_args *da = args;
+    int fd = da->fd;
+    int incomp_fd = da->incomp_fd;
+    char cpy_err_mesg[64];
+    int mesg_bytes;
 
     if ( (dump_mem_start = malloc(DUMP_INCREMENT*PAGE_SIZE)) == NULL )
     {

@@ -73,11 +85,11 @@ xc_domain_dumpcore_via_callback(int xc_h
                  (nr_pages * sizeof(xen_pfn_t)));
     header.xch_pages_offset = round_pgup(dummy_len);
 
-    sts = dump_rtn(args, (char *)&header, sizeof(struct xc_core_header));
-    if ( sts != 0 )
-        goto error_out;
-
-    sts = dump_rtn(args, (char *)&ctxt, sizeof(ctxt[0]) * nr_vcpus);
+    sts = dump_rtn(fd, (char *)&header, sizeof(struct xc_core_header));
+    if ( sts != 0 )
+        goto error_out;
+
+    sts = dump_rtn(fd, (char *)&ctxt, sizeof(ctxt[0]) * nr_vcpus);
     if ( sts != 0 )
         goto error_out;
 

@@ -91,27 +103,39 @@ xc_domain_dumpcore_via_callback(int xc_h
         IPRINTF("Could not get the page frame list\n");
         goto error_out;
     }
-    sts = dump_rtn(args, (char *)page_array, nr_pages * sizeof(xen_pfn_t));
+    sts = dump_rtn(fd, (char *)page_array, nr_pages * sizeof(xen_pfn_t));
     if ( sts != 0 )
         goto error_out;
 
     /* Pad the output data to page alignment. */
     memset(dummy, 0, PAGE_SIZE);
-    sts = dump_rtn(args, dummy, header.xch_pages_offset - dummy_len);
-    if ( sts != 0 )
-        goto error_out;
-
-    for ( dump_mem = dump_mem_start, i = 0; i < nr_pages; i++ )
-    {
-        copy_from_domain_page(xc_handle, domid, page_array[i], dump_mem);
+    sts = dump_rtn(fd, dummy, header.xch_pages_offset - dummy_len);
+    if ( sts != 0 )
+        goto error_out;
+
+    for ( dump_mem = dump_mem_start, n = 0; n < nr_pages; n++ )
+    {
+        sts = copy_from_domain_page(xc_handle, domid, page_array[i], dump_mem);
+        if( sts != 0 ){
+            memset(dump_mem, 0, PAGE_SIZE);
+            cpy_err_cnt++;
+            memset(cpy_err_mesg, 0, sizeof(cpy_err_mesg));
+            mesg_bytes = sprintf(cpy_err_mesg, "Cannot copy_from_domain_page (%lu)\n", n);
+            dump_rtn(incomp_fd, (char *)cpy_err_mesg, mesg_bytes);
+        }
+
         dump_mem += PAGE_SIZE;
-        if ( ((i + 1) % DUMP_INCREMENT == 0) || ((i + 1) == nr_pages) )
+        if ( ((n + 1) % DUMP_INCREMENT == 0) || ((n + 1) == nr_pages) )
         {
-            sts = dump_rtn(args, dump_mem_start, dump_mem - dump_mem_start);
+            sts = dump_rtn(fd, dump_mem_start, dump_mem - dump_mem_start);
             if ( sts != 0 )
                 goto error_out;
             dump_mem = dump_mem_start;
         }
+    }
+    if( cpy_err_cnt != 0 ){
+        IPRINTF("Could not copy from domid=%d (%d)pages\n", domid, cpy_err_cnt);
+        goto error_out;
     }
 
     free(dump_mem_start);

@@ -124,20 +148,14 @@ xc_domain_dumpcore_via_callback(int xc_h
     return -1;
 }
 
-/* Callback args for writing to a local dump file. */
-struct dump_args {
-    int     fd;
-};
-
 /* Callback routine for writing to a local dump file. */
-static int local_file_dump(void *args, char *buffer, unsigned int length)
-{
-    struct dump_args *da = args;
+static int local_file_dump(int fd, char *buffer, unsigned int length)
+{
     int bytes, offset;
 
     for ( offset = 0; offset < length; offset += bytes )
     {
-        bytes = write(da->fd, &buffer[offset], length-offset);
+        bytes = write(fd, &buffer[offset], length-offset);
         if ( bytes <= 0 )
         {
             PERROR("Failed to write buffer: %s", strerror(errno));

@@ -154,11 +172,26 @@ xc_domain_dumpcore(int xc_handle,
                    const char *corename)
 {
     struct dump_args da;
+    char *incomp_file;
     int sts;
 
     if ( (da.fd = open(corename, O_CREAT|O_RDWR, S_IWUSR|S_IRUSR)) < 0 )
     {
         PERROR("Could not open corefile %s: %s", corename, strerror(errno));
+        return -errno;
+    }
+
+    
+    if ( (incomp_file = (char *)malloc(sizeof(corename) + 12)) == NULL )
+    {
+        PERROR("Could not allocate incomp_file");
+        return -errno;
+    }
+
+    sprintf(incomp_file, "%s-incomp.list", corename);
+    if ( (da.incomp_fd = open(incomp_file, O_CREAT|O_RDWR, S_IWUSR|S_IRUSR)) < 0 )
+    {
+        PERROR("Could not open corefile %s: %s", incomp_file, strerror(errno));
         return -errno;
     }
 

@@ -166,6 +199,10 @@ xc_domain_dumpcore(int xc_handle,
         xc_handle, domid, &da, &local_file_dump);
 
     close(da.fd);
+    close(da.incomp_fd);
+
+    if( sts == 0)
+        unlink(incomp_file);
 
     return sts;
 }

diff -r 11626efd003c -r 0c43a1f62c85 tools/libxc/xenctrl.h
@@ -161,7 +161,7 @@ int xc_domain_dumpcore(int xc_handle,
  * and passes an opaque object for the use of the function and
  * created by the caller of xc_domain_dumpcore_via_callback.
  */
-typedef int (dumpcore_rtn_t)(void *arg, char *buffer, unsigned int length);
+typedef int (dumpcore_rtn_t)(int fd, char *buffer, unsigned int length);
 
 int xc_domain_dumpcore_via_callback(int xc_handle,
                                     uint32_t domid,