Merge remote-tracking branch 'stefanha/block' into staging

# By Paolo Bonzini (21) and others
# Via Stefan Hajnoczi
* stefanha/block: (42 commits)
  qemu-iotests: Fixed test case 026
  qemu-iotests: Whitespace cleanup
  dataplane: Fix startup race.
  block: look for zero blocks in bs->file
  block: add default get_block_status implementation for protocols
  raw-posix: report unwritten extents as zero
  raw-posix: return get_block_status data and flags
  docs, qapi: document qemu-img map
  qemu-img: add a "map" subcommand
  block: return BDRV_BLOCK_ZERO past end of backing file
  block: use bdrv_has_zero_init to return BDRV_BLOCK_ZERO
  block: return get_block_status data and flags for formats
  block: define get_block_status return value
  block: introduce bdrv_get_block_status API
  block: make bdrv_has_zero_init return false for copy-on-write-images
  qemu-img: always probe the input image for allocated sectors
  block: expect errors from bdrv_co_is_allocated
  block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above distinction
  block: do not use ->total_sectors in bdrv_co_is_allocated
  block: make bdrv_co_is_allocated static
  ...

Message-id: 1378481953-23099-1-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>

3 files changed, 148 insertions, 35 deletions

diff --git a/include/block/block.h b/include/block/block.h
index e6b391ce88..728ec1aebf 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -81,6 +81,32 @@ typedef struct BlockDevOps {
 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 
+/* BDRV_BLOCK_DATA: data is read from bs->file or another file
+ * BDRV_BLOCK_ZERO: sectors read as zero
+ * BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
+ *
+ * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
+ * bs->file where sector data can be read from as raw data.
+ *
+ * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
+ *
+ * DATA ZERO OFFSET_VALID
+ *  t    t        t       sectors read as zero, bs->file is zero at offset
+ *  t    f        t       sectors read as valid from bs->file at offset
+ *  f    t        t       sectors preallocated, read as zero, bs->file not
+ *                        necessarily zero at offset
+ *  f    f        t       sectors preallocated but read from backing_hd,
+ *                        bs->file contains garbage at offset
+ *  t    t        f       sectors preallocated, read as zero, unknown offset
+ *  t    f        f       sectors read from unknown file or offset
+ *  f    t        f       not allocated or unknown offset, read as zero
+ *  f    f        f       not allocated or unknown offset, read from backing_hd
+ */
+#define BDRV_BLOCK_DATA         1
+#define BDRV_BLOCK_ZERO         2
+#define BDRV_BLOCK_OFFSET_VALID 4
+#define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
+
 typedef enum {
     BDRV_ACTION_REPORT, BDRV_ACTION_IGNORE, BDRV_ACTION_STOP
 } BlockErrorAction;
@@ -107,7 +133,6 @@ void bdrv_info_stats(Monitor *mon, QObject **ret_data);
 /* disk I/O throttling */
 void bdrv_io_limits_enable(BlockDriverState *bs);
 void bdrv_io_limits_disable(BlockDriverState *bs);
-bool bdrv_io_limits_enabled(BlockDriverState *bs);
 
 void bdrv_init(void);
 void bdrv_init_with_whitelist(void);
@@ -123,7 +148,6 @@ BlockDriverState *bdrv_new(const char *device_name);
 void bdrv_make_anon(BlockDriverState *bs);
 void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old);
 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
-void bdrv_delete(BlockDriverState *bs);
 int bdrv_parse_cache_flags(const char *mode, int *flags);
 int bdrv_parse_discard_flags(const char *mode, int *flags);
 int bdrv_file_open(BlockDriverState **pbs, const char *filename,
@@ -181,12 +205,6 @@ int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
  */
 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors);
-int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
-    int nb_sectors, int *pnum);
-int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
-                                            BlockDriverState *base,
-                                            int64_t sector_num,
-                                            int nb_sectors, int *pnum);
 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
     const char *backing_file);
 int bdrv_get_backing_file_depth(BlockDriverState *bs);
@@ -277,6 +295,8 @@ int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 int bdrv_has_zero_init_1(BlockDriverState *bs);
 int bdrv_has_zero_init(BlockDriverState *bs);
+int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
+                              int nb_sectors, int *pnum);
 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
                       int *pnum);
 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
@@ -356,6 +376,8 @@ int64_t bdrv_get_dirty_count(BlockDriverState *bs);
 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 
+void bdrv_ref(BlockDriverState *bs);
+void bdrv_unref(BlockDriverState *bs);
 void bdrv_set_in_use(BlockDriverState *bs, int in_use);
 int bdrv_in_use(BlockDriverState *bs);
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8012e253c9..7c35198ad7 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -35,18 +35,12 @@
 #include "qemu/hbitmap.h"
 #include "block/snapshot.h"
 #include "qemu/main-loop.h"
+#include "qemu/throttle.h"
 
 #define BLOCK_FLAG_ENCRYPT          1
 #define BLOCK_FLAG_COMPAT6          4
 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
 
-#define BLOCK_IO_LIMIT_READ     0
-#define BLOCK_IO_LIMIT_WRITE    1
-#define BLOCK_IO_LIMIT_TOTAL    2
-
-#define BLOCK_IO_SLICE_TIME     100000000
-#define NANOSECONDS_PER_SECOND  1000000000.0
-
 #define BLOCK_OPT_SIZE              "size"
 #define BLOCK_OPT_ENCRYPT           "encryption"
 #define BLOCK_OPT_COMPAT6           "compat6"
@@ -70,17 +64,6 @@ typedef struct BdrvTrackedRequest {
     CoQueue wait_queue; /* coroutines blocked on this request */
 } BdrvTrackedRequest;
 
-
-typedef struct BlockIOLimit {
-    int64_t bps[3];
-    int64_t iops[3];
-} BlockIOLimit;
-
-typedef struct BlockIOBaseValue {
-    uint64_t bytes[2];
-    uint64_t ios[2];
-} BlockIOBaseValue;
-
 struct BlockDriver {
     const char *format_name;
     int instance_size;
@@ -135,7 +118,7 @@ struct BlockDriver {
         int64_t sector_num, int nb_sectors);
     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors);
-    int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
+    int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors, int *pnum);
 
     /*
@@ -264,13 +247,9 @@ struct BlockDriverState {
     /* number of in-flight copy-on-read requests */
     unsigned int copy_on_read_in_flight;
 
-    /* the time for latest disk I/O */
-    int64_t slice_start;
-    int64_t slice_end;
-    BlockIOLimit io_limits;
-    BlockIOBaseValue slice_submitted;
-    CoQueue      throttled_reqs;
-    QEMUTimer    *block_timer;
+    /* I/O throttling */
+    ThrottleState throttle_state;
+    CoQueue      throttled_reqs[2];
     bool         io_limits_enabled;
 
     /* I/O stats (display with "info blockstats"). */
@@ -298,6 +277,7 @@ struct BlockDriverState {
     BlockDeviceIoStatus iostatus;
     char device_name[32];
     HBitmap *dirty_bitmap;
+    int refcnt;
     int in_use; /* users other than guest access, eg. block migration */
     QTAILQ_ENTRY(BlockDriverState) list;
 
@@ -312,7 +292,8 @@ struct BlockDriverState {
 int get_tmp_filename(char *filename, int size);
 
 void bdrv_set_io_limits(BlockDriverState *bs,
-                        BlockIOLimit *io_limits);
+                        ThrottleConfig *cfg);
+
 
 /**
  * bdrv_add_before_write_notifier:
diff --git a/include/qemu/throttle.h b/include/qemu/throttle.h
new file mode 100644
index 0000000000..ab29b0b918
--- /dev/null
+++ b/include/qemu/throttle.h
@@ -0,0 +1,110 @@
+/*
+ * QEMU throttling infrastructure
+ *
+ * Copyright (C) Nodalink, SARL. 2013
+ *
+ * Author:
+ *   Benoît Canet <benoit.canet@irqsave.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef THROTTLE_H
+#define THROTTLE_H
+
+#include <stdint.h>
+#include "qemu-common.h"
+#include "qemu/timer.h"
+
+#define NANOSECONDS_PER_SECOND  1000000000.0
+
+typedef enum {
+    THROTTLE_BPS_TOTAL,
+    THROTTLE_BPS_READ,
+    THROTTLE_BPS_WRITE,
+    THROTTLE_OPS_TOTAL,
+    THROTTLE_OPS_READ,
+    THROTTLE_OPS_WRITE,
+    BUCKETS_COUNT,
+} BucketType;
+
+/*
+ * The max parameter of the leaky bucket throttling algorithm can be used to
+ * allow the guest to do bursts.
+ * The max value is a pool of I/O that the guest can use without being throttled
+ * at all. Throttling is triggered once this pool is empty.
+ */
+
+typedef struct LeakyBucket {
+    double  avg;              /* average goal in units per second */
+    double  max;              /* leaky bucket max burst in units */
+    double  level;            /* bucket level in units */
+} LeakyBucket;
+
+/* The following structure is used to configure a ThrottleState
+ * It contains a bit of state: the bucket field of the LeakyBucket structure.
+ * However it allows to keep the code clean and the bucket field is reset to
+ * zero at the right time.
+ */
+typedef struct ThrottleConfig {
+    LeakyBucket buckets[BUCKETS_COUNT]; /* leaky buckets */
+    uint64_t op_size;         /* size of an operation in bytes */
+} ThrottleConfig;
+
+typedef struct ThrottleState {
+    ThrottleConfig cfg;       /* configuration */
+    int64_t previous_leak;    /* timestamp of the last leak done */
+    QEMUTimer * timers[2];    /* timers used to do the throttling */
+    QEMUClockType clock_type; /* the clock used */
+} ThrottleState;
+
+/* operations on single leaky buckets */
+void throttle_leak_bucket(LeakyBucket *bkt, int64_t delta);
+
+int64_t throttle_compute_wait(LeakyBucket *bkt);
+
+/* expose timer computation function for unit tests */
+bool throttle_compute_timer(ThrottleState *ts,
+                            bool is_write,
+                            int64_t now,
+                            int64_t *next_timestamp);
+
+/* init/destroy cycle */
+void throttle_init(ThrottleState *ts,
+                   QEMUClockType clock_type,
+                   void (read_timer)(void *),
+                   void (write_timer)(void *),
+                   void *timer_opaque);
+
+void throttle_destroy(ThrottleState *ts);
+
+bool throttle_have_timer(ThrottleState *ts);
+
+/* configuration */
+bool throttle_enabled(ThrottleConfig *cfg);
+
+bool throttle_conflicting(ThrottleConfig *cfg);
+
+bool throttle_is_valid(ThrottleConfig *cfg);
+
+void throttle_config(ThrottleState *ts, ThrottleConfig *cfg);
+
+void throttle_get_config(ThrottleState *ts, ThrottleConfig *cfg);
+
+/* usage */
+bool throttle_schedule_timer(ThrottleState *ts, bool is_write);
+
+void throttle_account(ThrottleState *ts, bool is_write, uint64_t size);
+
+#endif