filemon: ensure watch IDs are unique to QFileMonitor scope

The watch IDs are mistakenly only unique within the scope of the
directory being monitored. This is not useful for clients which are
monitoring multiple directories. They require watch IDs to be unique
globally within the QFileMonitor scope.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Bandan Das <bsd@redhat.com>
Reviewed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

tests/test-util-filemonitor.c

@@ -35,6 +35,8 @@ enum {
     QFILE_MONITOR_TEST_OP_RENAME,
     QFILE_MONITOR_TEST_OP_TOUCH,
     QFILE_MONITOR_TEST_OP_UNLINK,
+    QFILE_MONITOR_TEST_OP_MKDIR,
+    QFILE_MONITOR_TEST_OP_RMDIR,
 };
 
 typedef struct {
@@ -298,6 +300,54 @@ test_file_monitor_events(void)
           .eventid = QFILE_MONITOR_EVENT_DELETED },
 
 
+        { .type = QFILE_MONITOR_TEST_OP_MKDIR,
+          .filesrc = "fish", },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "fish", .watchid = 0,
+          .eventid = QFILE_MONITOR_EVENT_CREATED },
+
+
+        { .type = QFILE_MONITOR_TEST_OP_ADD_WATCH,
+          .filesrc = "fish/", .watchid = 4 },
+        { .type = QFILE_MONITOR_TEST_OP_ADD_WATCH,
+          .filesrc = "fish/one.txt", .watchid = 5 },
+        { .type = QFILE_MONITOR_TEST_OP_CREATE,
+          .filesrc = "fish/one.txt", },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "one.txt", .watchid = 4,
+          .eventid = QFILE_MONITOR_EVENT_CREATED },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "one.txt", .watchid = 5,
+          .eventid = QFILE_MONITOR_EVENT_CREATED },
+
+
+        { .type = QFILE_MONITOR_TEST_OP_DEL_WATCH,
+          .filesrc = "fish/one.txt", .watchid = 5 },
+        { .type = QFILE_MONITOR_TEST_OP_RENAME,
+          .filesrc = "fish/one.txt", .filedst = "two.txt", },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "one.txt", .watchid = 4,
+          .eventid = QFILE_MONITOR_EVENT_DELETED },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "two.txt", .watchid = 0,
+          .eventid = QFILE_MONITOR_EVENT_CREATED },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "two.txt", .watchid = 2,
+          .eventid = QFILE_MONITOR_EVENT_CREATED },
+
+
+        { .type = QFILE_MONITOR_TEST_OP_RMDIR,
+          .filesrc = "fish", },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "", .watchid = 4,
+          .eventid = QFILE_MONITOR_EVENT_IGNORED },
+        { .type = QFILE_MONITOR_TEST_OP_EVENT,
+          .filesrc = "fish", .watchid = 0,
+          .eventid = QFILE_MONITOR_EVENT_DELETED },
+        { .type = QFILE_MONITOR_TEST_OP_DEL_WATCH,
+          .filesrc = "fish", .watchid = 4 },
+
+
         { .type = QFILE_MONITOR_TEST_OP_UNLINK,
           .filesrc = "two.txt", },
         { .type = QFILE_MONITOR_TEST_OP_EVENT,
@@ -366,6 +416,8 @@ test_file_monitor_events(void)
         int fd;
         int watchid;
         struct utimbuf ubuf;
+        char *watchdir;
+        const char *watchfile;
 
         pathsrc = g_strdup_printf("%s/%s", dir, op->filesrc);
         if (op->filedst) {
@@ -378,13 +430,26 @@ test_file_monitor_events(void)
                 g_printerr("Add watch %s %s %d\n",
                            dir, op->filesrc, op->watchid);
             }
+            if (op->filesrc && strchr(op->filesrc, '/')) {
+                watchdir = g_strdup_printf("%s/%s", dir, op->filesrc);
+                watchfile = strrchr(watchdir, '/');
+                *(char *)watchfile = '\0';
+                watchfile++;
+                if (*watchfile == '\0') {
+                    watchfile = NULL;
+                }
+            } else {
+                watchdir = g_strdup(dir);
+                watchfile = op->filesrc;
+            }
             watchid =
                 qemu_file_monitor_add_watch(mon,
-                                            dir,
+                                            watchdir,
-                                            op->filesrc,
+                                            watchfile,
                                             qemu_file_monitor_test_handler,
                                             &data,
                                             &local_err);
+            g_free(watchdir);
             if (watchid < 0) {
                 g_printerr("Unable to add watch %s",
                            error_get_pretty(local_err));
@@ -400,9 +465,17 @@ test_file_monitor_events(void)
             if (debug) {
                 g_printerr("Del watch %s %d\n", dir, op->watchid);
             }
+            if (op->filesrc && strchr(op->filesrc, '/')) {
+                watchdir = g_strdup_printf("%s/%s", dir, op->filesrc);
+                watchfile = strrchr(watchdir, '/');
+                *(char *)watchfile = '\0';
+            } else {
+                watchdir = g_strdup(dir);
+            }
             qemu_file_monitor_remove_watch(mon,
-                                           dir,
+                                           watchdir,
                                            op->watchid);
+            g_free(watchdir);
             break;
         case QFILE_MONITOR_TEST_OP_EVENT:
             if (debug) {
@@ -492,6 +565,28 @@ test_file_monitor_events(void)
             }
             break;
 
+        case QFILE_MONITOR_TEST_OP_MKDIR:
+            if (debug) {
+                g_printerr("Mkdir %s\n", pathsrc);
+            }
+            if (mkdir(pathsrc, 0700) < 0) {
+                g_printerr("Unable to mkdir %s: %s",
+                           pathsrc, strerror(errno));
+                goto cleanup;
+            }
+            break;
+
+        case QFILE_MONITOR_TEST_OP_RMDIR:
+            if (debug) {
+                g_printerr("Rmdir %s\n", pathsrc);
+            }
+            if (rmdir(pathsrc) < 0) {
+                g_printerr("Unable to rmdir %s: %s",
+                           pathsrc, strerror(errno));
+                goto cleanup;
+            }
+            break;
+
         default:
             g_assert_not_reached();
         }
@@ -532,13 +627,18 @@ test_file_monitor_events(void)
             const QFileMonitorTestOp *op = &(ops[i]);
             char *path = g_strdup_printf("%s/%s",
                                          dir, op->filesrc);
-            unlink(path);
+            if (op->type == QFILE_MONITOR_TEST_OP_MKDIR) {
-            g_free(path);
+                rmdir(path);
-            if (op->filedst) {
+                g_free(path);
-                path = g_strdup_printf("%s/%s",
+            } else {
-                                       dir, op->filedst);
                 unlink(path);
                 g_free(path);
+                if (op->filedst) {
+                    path = g_strdup_printf("%s/%s",
+                                           dir, op->filedst);
+                    unlink(path);
+                    g_free(path);
+                }
             }
         }
         if (rmdir(dir) < 0) {

util/filemonitor-inotify.c

@@ -29,7 +29,7 @@
 
 struct QFileMonitor {
     int fd;
-
+    int nextid; /* watch ID counter */
     QemuMutex lock; /* protects dirs & idmap */
     GHashTable *dirs; /* dirname => QFileMonitorDir */
     GHashTable *idmap; /* inotify ID => dirname */
@@ -47,7 +47,6 @@ typedef struct {
 typedef struct {
     char *path;
     int id; /* inotify ID */
-    int nextid; /* watch ID counter */
     GArray *watches; /* QFileMonitorWatch elements */
 } QFileMonitorDir;
 
@@ -277,7 +276,7 @@ qemu_file_monitor_add_watch(QFileMonitor *mon,
         }
     }
 
-    watch.id = dir->nextid++;
+    watch.id = mon->nextid++;
     watch.filename = g_strdup(filename);
     watch.cb = cb;
     watch.opaque = opaque;