fix PBS write callback with big blocks

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

debian/patches/pve/0047-pbs-handle-write-callback-with-big-blocks-correctly.patch

@@ -0,0 +1,86 @@
+From: Stefan Reiter <s.reiter@proxmox.com>
+Subject: PVE: handle PBS write callback with big blocks correctly
+
+Under certain conditions QEMU will push more than the given blocksize
+into the callback at once. Handle it like VMA does, by iterating the
+data until all is written.
+
+The block size is stored per backup device to be used in the callback.
+This avoids relying on PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE, in case it is
+made configurable in the future.
+
+Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
+---
+
+ pve-backup.c | 30 ++++++++++++++++++++++--------
+ 1 file changed, 22 insertions(+), 8 deletions(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index 77eb475563..40d8136f1a 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -67,6 +67,7 @@ opts_init(pvebackup_init);
+ typedef struct PVEBackupDevInfo {
+     BlockDriverState *bs;
+     size_t size;
++    uint64_t block_size;
+     uint8_t dev_id;
+     bool completed;
+     char targetfile[PATH_MAX];
+@@ -147,17 +148,28 @@ pvebackup_co_dump_pbs_cb(
+         return -1;
+     }
+ 
+-    pbs_res = proxmox_backup_co_write_data(backup_state.pbs, di->dev_id, buf, start, size, &local_err);
+-    qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
++    uint64_t transferred = 0;
++    uint64_t reused = 0;
++    while (transferred < size) {
++        uint64_t left = size - transferred;
++        uint64_t to_transfer = left < di->block_size ? left : di->block_size;
+ 
+-    if (pbs_res < 0) {
+-        pvebackup_propagate_error(local_err);
+-        return pbs_res;
+-    } else {
+-        size_t reused = (pbs_res == 0) ? size : 0;
+-        pvebackup_add_transfered_bytes(size, !buf ? size : 0, reused);
++        pbs_res = proxmox_backup_co_write_data(backup_state.pbs, di->dev_id,
++            buf ? buf + transferred : NULL, start + transferred, to_transfer, &local_err);
++        transferred += to_transfer;
++
++        if (pbs_res < 0) {
++            pvebackup_propagate_error(local_err);
++            qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
++            return pbs_res;
++        }
++
++        reused += pbs_res == 0 ? to_transfer : 0;
+     }
+ 
++    qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
++    pvebackup_add_transfered_bytes(size, !buf ? size : 0, reused);
++
+     return size;
+ }
+ 
+@@ -730,6 +742,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
+             PVEBackupDevInfo *di = (PVEBackupDevInfo *)l->data;
+             l = g_list_next(l);
+ 
++            di->block_size = dump_cb_block_size;
++
+             const char *devname = bdrv_get_device_name(di->bs);
+ 
+             BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(di->bs, PBS_BITMAP_NAME);
+-- 
+2.20.1
+
+
+
+_______________________________________________
+pbs-devel mailing list
+pbs-devel@lists.proxmox.com
+https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
+
+

debian/patches/series

@@ -46,3 +46,4 @@ pve/0043-PVE-fixup-pbs-backup-add-compress-and-encrypt-option.patch
 pve/0044-PVE-Add-PBS-block-driver-to-map-backup-archives-into.patch
 pve/0045-PVE-add-query_proxmox_support-QMP-command.patch
 pve/0046-pbs-fix-missing-crypt-and-compress-parameters.patch
+pve/0047-pbs-handle-write-callback-with-big-blocks-correctly.patch