debian/patches/pve/0046-PVE-handle-PBS-write-callback-with-big-blocks-correc.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Stefan Reiter <s.reiter@proxmox.com>
   3 Date: Wed, 19 Aug 2020 12:33:17 +0200
   4 Subject: [PATCH] PVE: handle PBS write callback with big blocks correctly
   5
   6 Under certain conditions QEMU will push more than the given blocksize
   7 into the callback at once. Handle it like VMA does, by iterating the
   8 data until all is written.
   9
  10 The block size is stored per backup device to be used in the callback.
  11 This avoids relying on PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE, in case it is
  12 made configurable in the future.
  13
  14 Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
  15 ---
  16  pve-backup.c | 30 ++++++++++++++++++++++--------
  17  1 file changed, 22 insertions(+), 8 deletions(-)
  18
  19 diff --git a/pve-backup.c b/pve-backup.c
  20 index cd3a132d8b..f14273645a 100644
  21 --- a/pve-backup.c
  22 +++ b/pve-backup.c
  23 @@ -67,6 +67,7 @@ opts_init(pvebackup_init);
  24  typedef struct PVEBackupDevInfo {
  25      BlockDriverState *bs;
  26      size_t size;
  27 +    uint64_t block_size;
  28      uint8_t dev_id;
  29      bool completed;
  30      char targetfile[PATH_MAX];
  31 @@ -147,17 +148,28 @@ pvebackup_co_dump_pbs_cb(
  32          return -1;
  33      }
  34
  35 -    pbs_res = proxmox_backup_co_write_data(backup_state.pbs, di->dev_id, buf, start, size, &local_err);
  36 -    qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
  37 +    uint64_t transferred = 0;
  38 +    uint64_t reused = 0;
  39 +    while (transferred < size) {
  40 +        uint64_t left = size - transferred;
  41 +        uint64_t to_transfer = left < di->block_size ? left : di->block_size;
  42
  43 -    if (pbs_res < 0) {
  44 -        pvebackup_propagate_error(local_err);
  45 -        return pbs_res;
  46 -    } else {
  47 -        size_t reused = (pbs_res == 0) ? size : 0;
  48 -        pvebackup_add_transfered_bytes(size, !buf ? size : 0, reused);
  49 +        pbs_res = proxmox_backup_co_write_data(backup_state.pbs, di->dev_id,
  50 +            buf ? buf + transferred : NULL, start + transferred, to_transfer, &local_err);
  51 +        transferred += to_transfer;
  52 +
  53 +        if (pbs_res < 0) {
  54 +            pvebackup_propagate_error(local_err);
  55 +            qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
  56 +            return pbs_res;
  57 +        }
  58 +
  59 +        reused += pbs_res == 0 ? to_transfer : 0;
  60      }
  61
  62 +    qemu_co_mutex_unlock(&backup_state.dump_callback_mutex);
  63 +    pvebackup_add_transfered_bytes(size, !buf ? size : 0, reused);
  64 +
  65      return size;
  66  }
  67
  68 @@ -726,6 +738,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
  69              PVEBackupDevInfo *di = (PVEBackupDevInfo *)l->data;
  70              l = g_list_next(l);
  71
  72 +            di->block_size = dump_cb_block_size;
  73 +
  74              const char *devname = bdrv_get_device_name(di->bs);
  75
  76              BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(di->bs, PBS_BITMAP_NAME);