[pve-devel] [PATCH qemu 04/23] PVE backup: save device name in device info structure

[Fiona Ebner]

The device name needs to be queried while holding the graph read lock
and since it doesn't change during the whole operation, just get it
once during setup and avoid the need to query it again in different
places.

Also in preparation to use it more often in error messages and for the
upcoming external backup access API.

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---
 pve-backup.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/pve-backup.c b/pve-backup.c
index 051ebffe48..33c23e53c2 100644
--- a/pve-backup.c
+++ b/pve-backup.c
@@ -94,6 +94,7 @@ typedef struct PVEBackupDevInfo {
     size_t size;
     uint64_t block_size;
     uint8_t dev_id;
+    char* device_name;
     int completed_ret; // INT_MAX if not completed
     BdrvDirtyBitmap *bitmap;
     BlockDriverState *target;
@@ -327,6 +328,8 @@ static void coroutine_fn pvebackup_co_complete_stream(void *opaque)
     }
 
     di->bs = NULL;
+    g_free(di->device_name);
+    di->device_name = NULL;
 
     assert(di->target == NULL);
 
@@ -621,9 +624,6 @@ static void create_backup_jobs_bh(void *opaque) {
 
         BlockDriverState *source_bs = di->bs;
         bool discard_source = false;
-        bdrv_graph_co_rdlock();
-        const char *job_id = bdrv_get_device_name(di->bs);
-        bdrv_graph_co_rdunlock();
         if (di->fleecing.bs) {
             if (setup_snapshot_access(di, &local_err) < 0) {
                 error_setg(errp, "setting up snapshot access for fleecing failed: %s",
@@ -654,7 +654,7 @@ static void create_backup_jobs_bh(void *opaque) {
         }
 
         BlockJob *job = backup_job_create(
-            job_id, source_bs, di->target, backup_state.speed, sync_mode, di->bitmap,
+            di->device_name, source_bs, di->target, backup_state.speed, sync_mode, di->bitmap,
             bitmap_mode, false, discard_source, NULL, &perf, BLOCKDEV_ON_ERROR_REPORT,
             BLOCKDEV_ON_ERROR_REPORT, JOB_DEFAULT, pvebackup_complete_cb, di, backup_state.txn,
             &local_err);
@@ -751,6 +751,7 @@ static GList coroutine_fn GRAPH_RDLOCK *get_device_info(
             }
             PVEBackupDevInfo *di = g_new0(PVEBackupDevInfo, 1);
             di->bs = bs;
+            di->device_name = g_strdup(bdrv_get_device_name(bs));
 
             if (fleecing && device_uses_fleecing(*d)) {
                 g_autofree gchar *fleecing_devid = g_strconcat(*d, "-fleecing", NULL);
@@ -789,6 +790,7 @@ static GList coroutine_fn GRAPH_RDLOCK *get_device_info(
 
             PVEBackupDevInfo *di = g_new0(PVEBackupDevInfo, 1);
             di->bs = bs;
+            di->device_name = g_strdup(bdrv_get_device_name(bs));
             di_list = g_list_append(di_list, di);
         }
     }
@@ -956,9 +958,6 @@ UuidInfo coroutine_fn *qmp_backup(
 
             di->block_size = dump_cb_block_size;
 
-            bdrv_graph_co_rdlock();
-            const char *devname = bdrv_get_device_name(di->bs);
-            bdrv_graph_co_rdunlock();
             PBSBitmapAction action = PBS_BITMAP_ACTION_NOT_USED;
             size_t dirty = di->size;
 
@@ -973,7 +972,8 @@ UuidInfo coroutine_fn *qmp_backup(
                     }
                     action = PBS_BITMAP_ACTION_NEW;
                 } else {
-                    expect_only_dirty = proxmox_backup_check_incremental(pbs, devname, di->size) != 0;
+                    expect_only_dirty =
+                        proxmox_backup_check_incremental(pbs, di->device_name, di->size) != 0;
                 }
 
                 if (expect_only_dirty) {
@@ -997,7 +997,8 @@ UuidInfo coroutine_fn *qmp_backup(
                 }
             }
 
-            int dev_id = proxmox_backup_co_register_image(pbs, devname, di->size, expect_only_dirty, errp);
+            int dev_id = proxmox_backup_co_register_image(pbs, di->device_name, di->size,
+                                                          expect_only_dirty, errp);
             if (dev_id < 0) {
                 goto err_mutex;
             }
@@ -1009,7 +1010,7 @@ UuidInfo coroutine_fn *qmp_backup(
             di->dev_id = dev_id;
 
             PBSBitmapInfo *info = g_malloc(sizeof(*info));
-            info->drive = g_strdup(devname);
+            info->drive = g_strdup(di->device_name);
             info->action = action;
             info->size = di->size;
             info->dirty = dirty;
@@ -1034,10 +1035,7 @@ UuidInfo coroutine_fn *qmp_backup(
                 goto err_mutex;
             }
 
-            bdrv_graph_co_rdlock();
-            const char *devname = bdrv_get_device_name(di->bs);
-            bdrv_graph_co_rdunlock();
-            di->dev_id = vma_writer_register_stream(vmaw, devname, di->size);
+            di->dev_id = vma_writer_register_stream(vmaw, di->device_name, di->size);
             if (di->dev_id <= 0) {
                 error_set(errp, ERROR_CLASS_GENERIC_ERROR,
                           "register_stream failed");
@@ -1148,6 +1146,9 @@ err:
             bdrv_co_unref(di->target);
         }
 
+        g_free(di->device_name);
+        di->device_name = NULL;
+
         g_free(di);
     }
     g_list_free(di_list);
-- 
2.39.2