Merge remote-tracking branch 'kwolf/for-anthony' into staging

# By Stefan Hajnoczi (4) and Kevin Wolf (3)
# Via Kevin Wolf
* kwolf/for-anthony:
  qcow2: Fix L1 write error handling in qcow2_update_snapshot_refcount
  qcow2: Return real error in qcow2_update_snapshot_refcount
  block: clean up I/O throttling wait_time code
  block: drop duplicated slice extension code
  block: keep I/O throttling slice time constant
  block: fix I/O throttling accounting blind spot
  usb-storage: Forward serial number to scsi-disk

8 files changed, 46 insertions, 47 deletions

diff --git a/block.c b/block.c
index 0ae2e93982..602d8a443e 100644
--- a/block.c
+++ b/block.c
@@ -140,8 +140,6 @@ void bdrv_io_limits_disable(BlockDriverState *bs)
 
     bs->slice_start = 0;
     bs->slice_end   = 0;
-    bs->slice_time  = 0;
-    memset(&bs->io_base, 0, sizeof(bs->io_base));
 }
 
 static void bdrv_block_timer(void *opaque)
@@ -1433,11 +1431,10 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
     bs_dest->enable_write_cache = bs_src->enable_write_cache;
 
     /* i/o timing parameters */
-    bs_dest->slice_time         = bs_src->slice_time;
     bs_dest->slice_start        = bs_src->slice_start;
     bs_dest->slice_end          = bs_src->slice_end;
+    bs_dest->slice_submitted    = bs_src->slice_submitted;
     bs_dest->io_limits          = bs_src->io_limits;
-    bs_dest->io_base            = bs_src->io_base;
     bs_dest->throttled_reqs     = bs_src->throttled_reqs;
     bs_dest->block_timer        = bs_src->block_timer;
     bs_dest->io_limits_enabled  = bs_src->io_limits_enabled;
@@ -3750,6 +3747,7 @@ static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
                  bool is_write, double elapsed_time, uint64_t *wait)
 {
     uint64_t bps_limit = 0;
+    uint64_t extension;
     double   bytes_limit, bytes_base, bytes_res;
     double   slice_time, wait_time;
 
@@ -3768,9 +3766,9 @@ static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
     slice_time = bs->slice_end - bs->slice_start;
     slice_time /= (NANOSECONDS_PER_SECOND);
     bytes_limit = bps_limit * slice_time;
-    bytes_base  = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write];
+    bytes_base  = bs->slice_submitted.bytes[is_write];
     if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
-        bytes_base += bs->nr_bytes[!is_write] - bs->io_base.bytes[!is_write];
+        bytes_base += bs->slice_submitted.bytes[!is_write];
     }
 
     /* bytes_base: the bytes of data which have been read/written; and
@@ -3797,10 +3795,12 @@ static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
      * info can be kept until the timer fire, so it is increased and tuned
      * based on the result of experiment.
      */
-    bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
-    bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
+    extension = wait_time * NANOSECONDS_PER_SECOND;
+    extension = DIV_ROUND_UP(extension, BLOCK_IO_SLICE_TIME) *
+                BLOCK_IO_SLICE_TIME;
+    bs->slice_end += extension;
     if (wait) {
-        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+        *wait = wait_time * NANOSECONDS_PER_SECOND;
     }
 
     return true;
@@ -3828,9 +3828,9 @@ static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
     slice_time = bs->slice_end - bs->slice_start;
     slice_time /= (NANOSECONDS_PER_SECOND);
     ios_limit  = iops_limit * slice_time;
-    ios_base   = bs->nr_ops[is_write] - bs->io_base.ios[is_write];
+    ios_base   = bs->slice_submitted.ios[is_write];
     if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
-        ios_base += bs->nr_ops[!is_write] - bs->io_base.ios[!is_write];
+        ios_base += bs->slice_submitted.ios[!is_write];
     }
 
     if (ios_base + 1 <= ios_limit) {
@@ -3841,7 +3841,7 @@ static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
         return false;
     }
 
-    /* Calc approx time to dispatch */
+    /* Calc approx time to dispatch, in seconds */
     wait_time = (ios_base + 1) / iops_limit;
     if (wait_time > elapsed_time) {
         wait_time = wait_time - elapsed_time;
@@ -3849,10 +3849,10 @@ static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
         wait_time = 0;
     }
 
-    bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
-    bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
+    /* Exceeded current slice, extend it by another slice time */
+    bs->slice_end += BLOCK_IO_SLICE_TIME;
     if (wait) {
-        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+        *wait = wait_time * NANOSECONDS_PER_SECOND;
     }
 
     return true;
@@ -3867,19 +3867,10 @@ static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
     int      bps_ret, iops_ret;
 
     now = qemu_get_clock_ns(vm_clock);
-    if ((bs->slice_start < now)
-        && (bs->slice_end > now)) {
-        bs->slice_end = now + bs->slice_time;
-    } else {
-        bs->slice_time  =  5 * BLOCK_IO_SLICE_TIME;
+    if (now > bs->slice_end) {
         bs->slice_start = now;
-        bs->slice_end   = now + bs->slice_time;
-
-        bs->io_base.bytes[is_write]  = bs->nr_bytes[is_write];
-        bs->io_base.bytes[!is_write] = bs->nr_bytes[!is_write];
-
-        bs->io_base.ios[is_write]    = bs->nr_ops[is_write];
-        bs->io_base.ios[!is_write]   = bs->nr_ops[!is_write];
+        bs->slice_end   = now + BLOCK_IO_SLICE_TIME;
+        memset(&bs->slice_submitted, 0, sizeof(bs->slice_submitted));
     }
 
     elapsed_time  = now - bs->slice_start;
@@ -3907,6 +3898,10 @@ static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
         *wait = 0;
     }
 
+    bs->slice_submitted.bytes[is_write] += (int64_t)nb_sectors *
+                                           BDRV_SECTOR_SIZE;
+    bs->slice_submitted.ios[is_write]++;
+
     return false;
 }
 
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index c38e970bf2..b32738f8d9 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -747,10 +747,9 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
     if (l1_table_offset != s->l1_table_offset) {
         l1_table = g_malloc0(align_offset(l1_size2, 512));
         l1_allocated = 1;
-        if (bdrv_pread(bs->file, l1_table_offset,
-                       l1_table, l1_size2) != l1_size2)
-        {
-            ret = -EIO;
+
+        ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2);
+        if (ret < 0) {
             goto fail;
         }
 
@@ -802,7 +801,7 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
                         }
 
                         if (refcount < 0) {
-                            ret = -EIO;
+                            ret = refcount;
                             goto fail;
                         }
                     }
@@ -833,7 +832,7 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
                 refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
             }
             if (refcount < 0) {
-                ret = -EIO;
+                ret = refcount;
                 goto fail;
             } else if (refcount == 1) {
                 l2_offset |= QCOW_OFLAG_COPIED;
@@ -852,14 +851,16 @@ fail:
     }
 
     /* Update L1 only if it isn't deleted anyway (addend = -1) */
-    if (addend >= 0 && l1_modified) {
-        for(i = 0; i < l1_size; i++)
+    if (ret == 0 && addend >= 0 && l1_modified) {
+        for (i = 0; i < l1_size; i++) {
             cpu_to_be64s(&l1_table[i]);
-        if (bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table,
-                        l1_size2) < 0)
-            goto fail;
-        for(i = 0; i < l1_size; i++)
+        }
+
+        ret = bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table, l1_size2);
+
+        for (i = 0; i < l1_size; i++) {
             be64_to_cpus(&l1_table[i]);
+        }
     }
     if (l1_allocated)
         g_free(l1_table);
diff --git a/blockdev.c b/blockdev.c
index 8cdc9ce16a..6dc999d802 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1069,7 +1069,6 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
     }
 
     bs->io_limits = io_limits;
-    bs->slice_time = BLOCK_IO_SLICE_TIME;
 
     if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
         bdrv_io_limits_enable(bs);
diff --git a/hw/pci/pci-hotplug.c b/hw/pci/pci-hotplug.c
index f38df30540..180ee07fef 100644
--- a/hw/pci/pci-hotplug.c
+++ b/hw/pci/pci-hotplug.c
@@ -99,7 +99,7 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
     dinfo->unit = qemu_opt_get_number(dinfo->opts, "unit", -1);
     dinfo->bus = scsibus->busnr;
     scsidev = scsi_bus_legacy_add_drive(scsibus, dinfo->bdrv, dinfo->unit,
-                                        false, -1);
+                                        false, -1, NULL);
     if (!scsidev) {
         return -1;
     }
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 08787c2a9b..ac2093a5ef 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -207,7 +207,8 @@ static int scsi_qdev_exit(DeviceState *qdev)
 
 /* handle legacy '-drive if=scsi,...' cmd line args */
 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
-                                      int unit, bool removable, int bootindex)
+                                      int unit, bool removable, int bootindex,
+                                      const char *serial)
 {
     const char *driver;
     DeviceState *dev;
@@ -221,6 +222,9 @@ SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
     if (object_property_find(OBJECT(dev), "removable", NULL)) {
         qdev_prop_set_bit(dev, "removable", removable);
     }
+    if (serial) {
+        qdev_prop_set_string(dev, "serial", serial);
+    }
     if (qdev_prop_set_drive(dev, "drive", bdrv) < 0) {
         qdev_free(dev);
         return NULL;
@@ -243,7 +247,7 @@ int scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
             continue;
         }
         qemu_opts_loc_restore(dinfo->opts);
-        if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit, false, -1)) {
+        if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit, false, -1, NULL)) {
             res = -1;
             break;
         }
diff --git a/hw/scsi.h b/hw/scsi.h
index 33e2e0bdf1..02a1497d7a 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -160,7 +160,8 @@ static inline SCSIBus *scsi_bus_from_device(SCSIDevice *d)
 }
 
 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
-                                      int unit, bool removable, int bootindex);
+                                      int unit, bool removable, int bootindex,
+                                      const char *serial);
 int scsi_bus_legacy_handle_cmdline(SCSIBus *bus);
 
 /*
diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index d3f01aa2a7..21651b3637 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -625,7 +625,7 @@ static int usb_msd_initfn_storage(USBDevice *dev)
     usb_desc_init(dev);
     scsi_bus_new(&s->bus, &s->dev.qdev, &usb_msd_scsi_info_storage);
     scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, !!s->removable,
-                                            s->conf.bootindex);
+                                            s->conf.bootindex, s->serial);
     if (!scsi_dev) {
         return -1;
     }
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0986a2d6ac..9aa98b5d12 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -252,11 +252,10 @@ struct BlockDriverState {
     unsigned int copy_on_read_in_flight;
 
     /* the time for latest disk I/O */
-    int64_t slice_time;
     int64_t slice_start;
     int64_t slice_end;
     BlockIOLimit io_limits;
-    BlockIOBaseValue  io_base;
+    BlockIOBaseValue slice_submitted;
     CoQueue      throttled_reqs;
     QEMUTimer    *block_timer;
     bool         io_limits_enabled;