unfinished suspend functions

diff --git a/lib/.exported_symbols b/lib/.exported_symbols
index 6dac95471310f637e9435893f3390ec803dab27c..9929fcd1eac31b27281983bde236f698229e6e1f 100644 (file)
--- a/lib/.exported_symbols
+++ b/lib/.exported_symbols
@@ -83,4 +83,6 @@ dm_hash_get_first
 dm_hash_get_next
 dm_driver_version
 dm_deptree_deactivate_children
+dm_deptree_suspend_children
+dm_deptree_children_use_uuid
 dm_set_selinux_context

diff --git a/lib/libdevmapper.h b/lib/libdevmapper.h
index f773026d8e3e718838d7d11371063c0056725bf0..e0dd6d61ad44b37719509c9ff8c60d51f4a82772 100644 (file)
--- a/lib/libdevmapper.h
+++ b/lib/libdevmapper.h
@@ -254,6 +254,23 @@ int dm_deptree_deactivate_children(struct deptree_node *dnode,
                                   const char *uuid_prefix,
                                   size_t uuid_prefix_len);
 
+/*
+ * Suspend a device plus all dependencies.
+ * Ignores devices that don't have a uuid starting with uuid_prefix.
+ */
+int dm_deptree_suspend_children(struct deptree_node *dnode,
+                                  const char *uuid_prefix,
+                                  size_t uuid_prefix_len);
+
+/*
+ * Is the uuid prefix present in the tree?
+ * Only returns 0 if every node was checked successfully.
+ * Returns 1 if the tree walk has to be aborted.
+ */
+int dm_deptree_children_use_uuid(struct deptree_node *dnode,
+                                const char *uuid_prefix,
+                                size_t uuid_prefix_len);
+
 /*****************************************************************************
  * Library functions
  *****************************************************************************/

diff --git a/lib/libdm-deptree.c b/lib/libdm-deptree.c
index f5acf19d3b30db14dae7ba29c4d84f313923a2fd..2612896e7accc200224fbb874ac4c976ec5295c7 100644 (file)
--- a/lib/libdm-deptree.c
+++ b/lib/libdm-deptree.c
@@ -402,7 +402,8 @@ struct deptree_node *dm_deptree_next_child(void **handle,
 /*
  * Deactivate a device with its dependencies if the uuid prefix matches.
  */
-static int _info_by_dev(uint32_t major, uint32_t minor, struct dm_info *info)
+static int _info_by_dev(uint32_t major, uint32_t minor, int with_open_count,
+                       struct dm_info *info)
 {
        struct dm_task *dmt;
        int r;
@@ -418,6 +419,9 @@ static int _info_by_dev(uint32_t major, uint32_t minor, struct dm_info *info)
                return 0;
        }
 
+       if (!with_open_count && !dm_task_no_open_count(dmt))
+               log_error("Failed to disable open_count");
+
        if ((r = dm_task_run(dmt)))
                r = dm_task_get_info(dmt, info);
 
@@ -449,6 +453,38 @@ static int _deactivate_node(const char *name, uint32_t major, uint32_t minor)
 
        r = dm_task_run(dmt);
 
+       /* FIXME Remove node from tree or mark invalid? */
+
+       dm_task_destroy(dmt);
+
+       return r;
+}
+
+static int _suspend_node(const char *name, uint32_t major, uint32_t minor,
+                        struct dm_info *newinfo)
+{
+       struct dm_task *dmt;
+       int r;
+
+       log_verbose("Suspending %s (%" PRIu32 ":%" PRIu32 ")", name, major, minor);
+
+       if (!(dmt = dm_task_create(DM_DEVICE_SUSPEND))) {
+               log_error("Suspend dm_task creation failed for %s", name);
+               return 0;
+       }
+
+       if (!dm_task_set_major(dmt, major) || !dm_task_set_minor(dmt, minor)) {
+               log_error("Failed to set device number for %s suspension.", name);
+               dm_task_destroy(dmt);
+               return 0;
+       }
+
+       if (!dm_task_no_open_count(dmt))
+               log_error("Failed to disable open_count");
+
+       if ((r = dm_task_run(dmt)))
+               r = dm_task_get_info(dmt, newinfo);
+
        dm_task_destroy(dmt);
 
        return r;
@@ -486,7 +522,7 @@ int dm_deptree_deactivate_children(struct deptree_node *dnode,
                        continue;
 
                /* Refresh open_count */
-               if (!_info_by_dev(dinfo->major, dinfo->minor, &info) ||
+               if (!_info_by_dev(dinfo->major, dinfo->minor, 1, &info) ||
                    !info.exists || info.open_count)
                        continue;
 
@@ -503,3 +539,84 @@ int dm_deptree_deactivate_children(struct deptree_node *dnode,
 
        return 1;
 }
+
+/* FIXME Walk breadth first? */
+int dm_deptree_suspend_children(struct deptree_node *dnode,
+                                  const char *uuid_prefix,
+                                  size_t uuid_prefix_len)
+{
+       void *handle = NULL;
+       struct deptree_node *child = dnode;
+       struct dm_info info, newinfo;
+       const struct dm_info *dinfo;
+       const char *name;
+       const char *uuid;
+
+       while ((child = dm_deptree_next_child(&handle, dnode, 0))) {
+               if (!(dinfo = dm_deptree_node_get_info(child))) {
+                       stack;
+                       continue;
+               }
+
+               if (!(name = dm_deptree_node_get_name(child))) {
+                       stack;
+                       continue;
+               }
+
+               if (!(uuid = dm_deptree_node_get_uuid(child))) {
+                       stack;
+                       continue;
+               }
+
+               /* Ignore if it doesn't belong to this VG */
+               if (uuid_prefix && strncmp(uuid, uuid_prefix, uuid_prefix_len))
+                       continue;
+
+               /* FIXME Ensure parents are already suspended */
+               if (!_info_by_dev(dinfo->major, dinfo->minor, 0, &info) ||
+                   !info.exists)
+                       continue;
+
+               if (!_suspend_node(name, info.major, info.minor, &newinfo)) {
+                       log_error("Unable to suspend %s (%" PRIu32
+                                 ":%" PRIu32 ")", name, info.major,
+                                 info.minor);
+                       continue;
+               }
+
+               /* Update cached info */
+               child->info = newinfo;
+
+               if (dm_deptree_node_num_children(child, 0))
+                       dm_deptree_suspend_children(child, uuid_prefix, uuid_prefix_len);
+       }
+
+       return 1;
+}
+
+/*
+ * Returns 1 if unsure.
+ */
+int dm_deptree_children_use_uuid(struct deptree_node *dnode,
+                                const char *uuid_prefix,
+                                size_t uuid_prefix_len)
+{
+       void *handle = NULL;
+       struct deptree_node *child = dnode;
+       const char *uuid;
+
+       while ((child = dm_deptree_next_child(&handle, dnode, 0))) {
+               if (!(uuid = dm_deptree_node_get_uuid(child))) {
+                       log_error("Failed to get uuid for deptree node.");
+                       return 1;
+               }
+
+               if (!strncmp(uuid, uuid_prefix, uuid_prefix_len))
+                       return 1;
+
+               if (dm_deptree_node_num_children(child, 0))
+                       dm_deptree_children_use_uuid(child, uuid_prefix, uuid_prefix_len);
+       }
+
+       return 0;
+}