From 09615257058a0ae87b837bb041f56f7312d9ead8 Mon Sep 17 00:00:00 2001
From: Nir Soffer <nirsof@gmail.com>
Date: Fri, 13 Aug 2021 23:55:19 +0300
Subject: [PATCH 01/19] qemu-nbd: Change default cache mode to writeback
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Both qemu and qemu-img use writeback cache mode by default, which is
already documented in qemu(1). qemu-nbd uses writethrough cache mode by
default, and the default cache mode is not documented.

According to the qemu-nbd(8):

   --cache=CACHE
          The  cache  mode  to be used with the file.  See the
          documentation of the emulator's -drive cache=... option for
          allowed values.

qemu(1) says:

    The default mode is cache=writeback.

So users have no reason to assume that qemu-nbd is using writethough
cache mode. The only hint is the painfully slow writing when using the
defaults.

Looking in git history, it seems that qemu used writethrough in the past
to support broken guests that did not flush data properly, or could not
flush due to limitations in qemu. But qemu-nbd clients can use
NBD_CMD_FLUSH to flush data, so using writethrough does not help anyone.

Change the default cache mode to writback, and document the default and
available values properly in the online help and manual.

With this change converting image via qemu-nbd is 3.5 times faster.

    $ qemu-img create dst.img 50g
    $ qemu-nbd -t -f raw -k /tmp/nbd.sock dst.img

Before this change:

    $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock"
    Benchmark #1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock
      Time (mean ± σ):     83.639 s ±  5.970 s    [User: 2.733 s, System: 6.112 s]
      Range (min … max):   76.749 s … 87.245 s    3 runs

After this change:

    $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock"
    Benchmark #1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock
      Time (mean ± σ):     23.522 s ±  0.433 s    [User: 2.083 s, System: 5.475 s]
      Range (min … max):   23.234 s … 24.019 s    3 runs

Users can avoid the issue by using --cache=writeback[1] but the defaults
should give good performance for the common use case.

[1] https://bugzilla.redhat.com/1990656

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-Id: <20210813205519.50518-1-nsoffer@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 docs/tools/qemu-nbd.rst | 6 ++++--
 qemu-nbd.c              | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst
index e39a9f4b1a..56e54cd441 100644
--- a/docs/tools/qemu-nbd.rst
+++ b/docs/tools/qemu-nbd.rst
@@ -99,8 +99,10 @@ driver options if ``--image-opts`` is specified.
 
 .. option:: --cache=CACHE
 
-  The cache mode to be used with the file.  See the documentation of
-  the emulator's ``-drive cache=...`` option for allowed values.
+  The cache mode to be used with the file. Valid values are:
+  ``none``, ``writeback`` (the default), ``writethrough``,
+  ``directsync`` and ``unsafe``. See the documentation of
+  the emulator's ``-drive cache=...`` option for more info.
 
 .. option:: -n, --nocache
 
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 65ebec598f..9d895ba24b 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -135,7 +135,9 @@ static void usage(const char *name)
 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 "                            '[ID_OR_NAME]'\n"
 "  -n, --nocache             disable host cache\n"
-"      --cache=MODE          set cache mode (none, writeback, ...)\n"
+"      --cache=MODE          set cache mode used to access the disk image, the\n"
+"                            valid options are: 'none', 'writeback' (default),\n"
+"                            'writethrough', 'directsync' and 'unsafe'\n"
 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
@@ -552,7 +554,7 @@ int main(int argc, char **argv)
     bool alloc_depth = false;
     const char *tlscredsid = NULL;
     bool imageOpts = false;
-    bool writethrough = true;
+    bool writethrough = false; /* Client will flush as needed. */
     bool fork_process = false;
     bool list = false;
     int old_stderr = -1;

From b984b2968b415759307558493b1a2bb6070a2251 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:27:57 +0300
Subject: [PATCH 02/19] block/io: bring request check to
 bdrv_co_(read,write)v_vmstate

Only qcow2 driver supports vmstate.
In qcow2 these requests go through .bdrv_co_p{read,write}v_part
handlers.

So, let's do our basic check for the request on vmstate generic
handlers.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-2-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index 99ee182ca4..58602f84db 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2810,7 +2810,12 @@ bdrv_co_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverState *child_bs = bdrv_primary_bs(bs);
-    int ret = -ENOTSUP;
+    int ret;
+
+    ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
+    if (ret < 0) {
+        return ret;
+    }
 
     if (!drv) {
         return -ENOMEDIUM;
@@ -2822,6 +2827,8 @@ bdrv_co_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
         ret = drv->bdrv_load_vmstate(bs, qiov, pos);
     } else if (child_bs) {
         ret = bdrv_co_readv_vmstate(child_bs, qiov, pos);
+    } else {
+        ret = -ENOTSUP;
     }
 
     bdrv_dec_in_flight(bs);
@@ -2834,7 +2841,12 @@ bdrv_co_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverState *child_bs = bdrv_primary_bs(bs);
-    int ret = -ENOTSUP;
+    int ret;
+
+    ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
+    if (ret < 0) {
+        return ret;
+    }
 
     if (!drv) {
         return -ENOMEDIUM;
@@ -2846,6 +2858,8 @@ bdrv_co_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
         ret = drv->bdrv_save_vmstate(bs, qiov, pos);
     } else if (child_bs) {
         ret = bdrv_co_writev_vmstate(child_bs, qiov, pos);
+    } else {
+        ret = -ENOTSUP;
     }
 
     bdrv_dec_in_flight(bs);

From 558902cc3dc61231930001b82dcd95d20d58b417 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:27:58 +0300
Subject: [PATCH 03/19] qcow2: check request on vmstate save/load path

We modify the request by adding an offset to vmstate. Let's check the
modified request. It will help us to safely move .bdrv_co_preadv_part
and .bdrv_co_pwritev_part to int64_t type of offset and bytes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c                |  6 +++---
 block/qcow2.c             | 43 +++++++++++++++++++++++++++++++++------
 include/block/block_int.h |  3 +++
 3 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/block/io.c b/block/io.c
index 58602f84db..a4f124f755 100644
--- a/block/io.c
+++ b/block/io.c
@@ -956,9 +956,9 @@ bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
     return waited;
 }
 
-static int bdrv_check_qiov_request(int64_t offset, int64_t bytes,
-                                   QEMUIOVector *qiov, size_t qiov_offset,
-                                   Error **errp)
+int bdrv_check_qiov_request(int64_t offset, int64_t bytes,
+                            QEMUIOVector *qiov, size_t qiov_offset,
+                            Error **errp)
 {
     /*
      * Check generic offset/bytes correctness
diff --git a/block/qcow2.c b/block/qcow2.c
index 02f9f3e636..1c3cf7f91d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -5227,24 +5227,55 @@ static int qcow2_has_zero_init(BlockDriverState *bs)
     }
 }
 
+/*
+ * Check the request to vmstate. On success return
+ *      qcow2_vm_state_offset(bs) + @pos
+ */
+static int64_t qcow2_check_vmstate_request(BlockDriverState *bs,
+                                           QEMUIOVector *qiov, int64_t pos)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int64_t vmstate_offset = qcow2_vm_state_offset(s);
+    int ret;
+
+    /* Incoming requests must be OK */
+    bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort);
+
+    if (INT64_MAX - pos < vmstate_offset) {
+        return -EIO;
+    }
+
+    pos += vmstate_offset;
+    ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return pos;
+}
+
 static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
                               int64_t pos)
 {
-    BDRVQcow2State *s = bs->opaque;
+    int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
+    if (offset < 0) {
+        return offset;
+    }
 
     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
-    return bs->drv->bdrv_co_pwritev_part(bs, qcow2_vm_state_offset(s) + pos,
-                                         qiov->size, qiov, 0, 0);
+    return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0);
 }
 
 static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
                               int64_t pos)
 {
-    BDRVQcow2State *s = bs->opaque;
+    int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
+    if (offset < 0) {
+        return offset;
+    }
 
     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
-    return bs->drv->bdrv_co_preadv_part(bs, qcow2_vm_state_offset(s) + pos,
-                                        qiov->size, qiov, 0, 0);
+    return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0);
 }
 
 /*
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5451f89b8d..ed60495938 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -94,6 +94,9 @@ typedef struct BdrvTrackedRequest {
     struct BdrvTrackedRequest *waiting_for;
 } BdrvTrackedRequest;
 
+int bdrv_check_qiov_request(int64_t offset, int64_t bytes,
+                            QEMUIOVector *qiov, size_t qiov_offset,
+                            Error **errp);
 int bdrv_check_request(int64_t offset, int64_t bytes, Error **errp);
 
 struct BlockDriver {

From f7ef38dd1310d7d9db76d0aa16899cbc5744f36d Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:27:59 +0300
Subject: [PATCH 04/19] block: use int64_t instead of uint64_t in driver read
 handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver read handlers parameters which are already 64bit to
signed type.

While being here, convert also flags parameter to be BdrvRequestFlags.

Now let's consider all callers. Simple

  git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?'

shows that's there three callers of driver function:

 bdrv_driver_preadv() in block/io.c, passes int64_t, checked by
   bdrv_check_qiov_request() to be non-negative.

 qcow2_load_vmstate() does bdrv_check_qiov_request().

 do_perform_cow_read() has uint64_t argument. And a lot of things in
 qcow2 driver are uint64_t, so converting it is big job. But we must
 not work with requests that don't satisfy bdrv_check_qiov_request(),
 so let's just assert it here.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

The only one such caller:

    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1);
    ...
    ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0);

in tests/unit/test-bdrv-drain.c, and it's OK obviously.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix typos]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/blkdebug.c                 |  4 ++--
 block/blklogwrites.c             |  4 ++--
 block/blkreplay.c                |  2 +-
 block/blkverify.c                |  4 ++--
 block/bochs.c                    |  4 ++--
 block/cloop.c                    |  4 ++--
 block/commit.c                   |  2 +-
 block/copy-before-write.c        |  4 ++--
 block/copy-on-read.c             |  4 ++--
 block/crypto.c                   |  4 ++--
 block/curl.c                     |  3 ++-
 block/dmg.c                      |  4 ++--
 block/file-posix.c               |  6 +++---
 block/file-win32.c               |  4 ++--
 block/filter-compress.c          |  4 ++--
 block/mirror.c                   |  2 +-
 block/nbd.c                      |  5 +++--
 block/nfs.c                      |  6 +++---
 block/null.c                     |  9 +++++----
 block/nvme.c                     |  5 +++--
 block/preallocate.c              |  4 ++--
 block/qcow.c                     |  6 +++---
 block/qcow2-cluster.c            | 14 +++++++++++++-
 block/qcow2.c                    |  5 +++--
 block/quorum.c                   |  4 ++--
 block/raw-format.c               | 20 ++++++++++----------
 block/rbd.c                      |  6 +++---
 block/throttle.c                 |  5 +++--
 block/vdi.c                      |  4 ++--
 block/vmdk.c                     |  4 ++--
 block/vpc.c                      |  4 ++--
 block/vvfat.c                    |  4 ++--
 include/block/block_int.h        | 11 ++++++-----
 tests/unit/test-bdrv-drain.c     | 16 +++++++++-------
 tests/unit/test-block-iothread.c | 19 ++++++++++++++-----
 35 files changed, 120 insertions(+), 90 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 8b67554bec..12b8419065 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -631,8 +631,8 @@ static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 }
 
 static int coroutine_fn
-blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                   QEMUIOVector *qiov, int flags)
+blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                   QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int err;
 
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index b7579370a3..de3d4ba2b6 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -301,8 +301,8 @@ static void blk_log_writes_refresh_limits(BlockDriverState *bs, Error **errp)
 }
 
 static int coroutine_fn
-blk_log_writes_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                         QEMUIOVector *qiov, int flags)
+blk_log_writes_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                         QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 }
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 4a247752fd..13ea2166bb 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -72,7 +72,7 @@ static void block_request_create(uint64_t reqid, BlockDriverState *bs,
 }
 
 static int coroutine_fn blkreplay_co_preadv(BlockDriverState *bs,
-    uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
diff --git a/block/blkverify.c b/block/blkverify.c
index 188d7632fa..5e35744b8a 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -221,8 +221,8 @@ blkverify_co_prwv(BlockDriverState *bs, BlkverifyRequest *r, uint64_t offset,
 }
 
 static int coroutine_fn
-blkverify_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                    QEMUIOVector *qiov, int flags)
+blkverify_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                    QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BlkverifyRequest r;
     QEMUIOVector raw_qiov;
diff --git a/block/bochs.c b/block/bochs.c
index 2f010ab40a..4d68658087 100644
--- a/block/bochs.c
+++ b/block/bochs.c
@@ -238,8 +238,8 @@ static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
 }
 
 static int coroutine_fn
-bochs_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                QEMUIOVector *qiov, int flags)
+bochs_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVBochsState *s = bs->opaque;
     uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
diff --git a/block/cloop.c b/block/cloop.c
index c99192a57f..b8c6d0eccd 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -245,8 +245,8 @@ static inline int cloop_read_block(BlockDriverState *bs, int block_num)
 }
 
 static int coroutine_fn
-cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                QEMUIOVector *qiov, int flags)
+cloop_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVCloopState *s = bs->opaque;
     uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
diff --git a/block/commit.c b/block/commit.c
index 42792b4556..10cc5ff451 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -207,7 +207,7 @@ static const BlockJobDriver commit_job_driver = {
 };
 
 static int coroutine_fn bdrv_commit_top_preadv(BlockDriverState *bs,
-    uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 2a5e57deca..591cc3ac75 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -40,8 +40,8 @@ typedef struct BDRVCopyBeforeWriteState {
 } BDRVCopyBeforeWriteState;
 
 static coroutine_fn int cbw_co_preadv(
-        BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-        QEMUIOVector *qiov, int flags)
+        BlockDriverState *bs, int64_t offset, int64_t bytes,
+        QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 }
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index c428682272..d34add4476 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -128,10 +128,10 @@ static int64_t cor_getlength(BlockDriverState *bs)
 
 
 static int coroutine_fn cor_co_preadv_part(BlockDriverState *bs,
-                                           uint64_t offset, uint64_t bytes,
+                                           int64_t offset, int64_t bytes,
                                            QEMUIOVector *qiov,
                                            size_t qiov_offset,
-                                           int flags)
+                                           BdrvRequestFlags flags)
 {
     int64_t n;
     int local_flags;
diff --git a/block/crypto.c b/block/crypto.c
index 1d30fde38e..a732a36d10 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -397,8 +397,8 @@ static int block_crypto_reopen_prepare(BDRVReopenState *state,
 #define BLOCK_CRYPTO_MAX_IO_SIZE (1024 * 1024)
 
 static coroutine_fn int
-block_crypto_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                       QEMUIOVector *qiov, int flags)
+block_crypto_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                       QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BlockCrypto *crypto = bs->opaque;
     uint64_t cur_bytes; /* number of bytes in current iteration */
diff --git a/block/curl.c b/block/curl.c
index 50e741a0d7..4a8ae2b269 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -896,7 +896,8 @@ out:
 }
 
 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+        BdrvRequestFlags flags)
 {
     CURLAIOCB acb = {
         .co = qemu_coroutine_self(),
diff --git a/block/dmg.c b/block/dmg.c
index ef35a505f2..447901fbb8 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -689,8 +689,8 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
 }
 
 static int coroutine_fn
-dmg_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-              QEMUIOVector *qiov, int flags)
+dmg_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+              QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVDMGState *s = bs->opaque;
     uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
diff --git a/block/file-posix.c b/block/file-posix.c
index d81e15efa4..df4a67f8b2 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2077,9 +2077,9 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
     return raw_thread_pool_submit(bs, handle_aiocb_rw, &acb);
 }
 
-static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
-                                      uint64_t bytes, QEMUIOVector *qiov,
-                                      int flags)
+static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes, QEMUIOVector *qiov,
+                                      BdrvRequestFlags flags)
 {
     return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_READ);
 }
diff --git a/block/file-win32.c b/block/file-win32.c
index b97c58d642..4e8947009b 100644
--- a/block/file-win32.c
+++ b/block/file-win32.c
@@ -440,8 +440,8 @@ fail:
 }
 
 static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
-                                  uint64_t offset, uint64_t bytes,
-                                  QEMUIOVector *qiov, int flags,
+                                  int64_t offset, int64_t bytes,
+                                  QEMUIOVector *qiov, BdrvRequestFlags flags,
                                   BlockCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
diff --git a/block/filter-compress.c b/block/filter-compress.c
index 5136371bf8..54a16c6c64 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -63,10 +63,10 @@ static int64_t compress_getlength(BlockDriverState *bs)
 
 
 static int coroutine_fn compress_co_preadv_part(BlockDriverState *bs,
-                                                uint64_t offset, uint64_t bytes,
+                                                int64_t offset, int64_t bytes,
                                                 QEMUIOVector *qiov,
                                                 size_t qiov_offset,
-                                                int flags)
+                                                BdrvRequestFlags flags)
 {
     return bdrv_co_preadv_part(bs->file, offset, bytes, qiov, qiov_offset,
                                flags);
diff --git a/block/mirror.c b/block/mirror.c
index 85b781bc21..e24d0aedd5 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1402,7 +1402,7 @@ static void coroutine_fn active_write_settle(MirrorOp *op)
 }
 
 static int coroutine_fn bdrv_mirror_top_preadv(BlockDriverState *bs,
-    uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
diff --git a/block/nbd.c b/block/nbd.c
index f6ff1c4fb4..c816933d7d 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1322,8 +1322,9 @@ static int nbd_co_request(BlockDriverState *bs, NBDRequest *request,
     return ret ? ret : request_ret;
 }
 
-static int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,
-                                uint64_t bytes, QEMUIOVector *qiov, int flags)
+static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset,
+                                int64_t bytes, QEMUIOVector *qiov,
+                                BdrvRequestFlags flags)
 {
     int ret, request_ret;
     Error *local_err = NULL;
diff --git a/block/nfs.c b/block/nfs.c
index 9aeaefb364..27f9ab8307 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -262,9 +262,9 @@ nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
                                      nfs_co_generic_bh_cb, task);
 }
 
-static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, uint64_t offset,
-                                      uint64_t bytes, QEMUIOVector *iov,
-                                      int flags)
+static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes, QEMUIOVector *iov,
+                                      BdrvRequestFlags flags)
 {
     NFSClient *client = bs->opaque;
     NFSRPC task;
diff --git a/block/null.c b/block/null.c
index cc9b1d4ea7..343dbb580d 100644
--- a/block/null.c
+++ b/block/null.c
@@ -116,8 +116,9 @@ static coroutine_fn int null_co_common(BlockDriverState *bs)
 }
 
 static coroutine_fn int null_co_preadv(BlockDriverState *bs,
-                                       uint64_t offset, uint64_t bytes,
-                                       QEMUIOVector *qiov, int flags)
+                                       int64_t offset, int64_t bytes,
+                                       QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     BDRVNullState *s = bs->opaque;
 
@@ -187,8 +188,8 @@ static inline BlockAIOCB *null_aio_common(BlockDriverState *bs,
 }
 
 static BlockAIOCB *null_aio_preadv(BlockDriverState *bs,
-                                   uint64_t offset, uint64_t bytes,
-                                   QEMUIOVector *qiov, int flags,
+                                   int64_t offset, int64_t bytes,
+                                   QEMUIOVector *qiov, BdrvRequestFlags flags,
                                    BlockCompletionFunc *cb,
                                    void *opaque)
 {
diff --git a/block/nvme.c b/block/nvme.c
index abfe305baf..f812eb1cc2 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1251,8 +1251,9 @@ static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 }
 
 static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
-                                       uint64_t offset, uint64_t bytes,
-                                       QEMUIOVector *qiov, int flags)
+                                       int64_t offset, int64_t bytes,
+                                       QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     return nvme_co_prw(bs, offset, bytes, qiov, false, flags);
 }
diff --git a/block/preallocate.c b/block/preallocate.c
index b619206304..5709443612 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -227,8 +227,8 @@ static void preallocate_reopen_abort(BDRVReopenState *state)
 }
 
 static coroutine_fn int preallocate_co_preadv_part(
-        BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-        QEMUIOVector *qiov, size_t qiov_offset, int flags)
+        BlockDriverState *bs, int64_t offset, int64_t bytes,
+        QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags)
 {
     return bdrv_co_preadv_part(bs->file, offset, bytes, qiov, qiov_offset,
                                flags);
diff --git a/block/qcow.c b/block/qcow.c
index f8919a44d1..1151b8d79b 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -617,9 +617,9 @@ static void qcow_refresh_limits(BlockDriverState *bs, Error **errp)
     bs->bl.request_alignment = BDRV_SECTOR_SIZE;
 }
 
-static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
-                                       uint64_t bytes, QEMUIOVector *qiov,
-                                       int flags)
+static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, int64_t offset,
+                                       int64_t bytes, QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     BDRVQcowState *s = bs->opaque;
     int offset_in_cluster;
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 4ebb49a087..5727f92dcb 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -505,7 +505,19 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
         return -ENOMEDIUM;
     }
 
-    /* Call .bdrv_co_readv() directly instead of using the public block-layer
+    /*
+     * We never deal with requests that don't satisfy
+     * bdrv_check_qiov_request(), and aligning requests to clusters never
+     * breaks this condition. So, do some assertions before calling
+     * bs->drv->bdrv_co_preadv_part() which has int64_t arguments.
+     */
+    assert(src_cluster_offset <= INT64_MAX);
+    assert(src_cluster_offset + offset_in_cluster <= INT64_MAX);
+    assert(qiov->size <= INT64_MAX);
+    bdrv_check_qiov_request(src_cluster_offset + offset_in_cluster, qiov->size,
+                            qiov, 0, &error_abort);
+    /*
+     * Call .bdrv_co_readv() directly instead of using the public block-layer
      * interface.  This avoids double I/O throttling and request tracking,
      * which can lead to deadlock when block layer copy-on-read is enabled.
      */
diff --git a/block/qcow2.c b/block/qcow2.c
index 1c3cf7f91d..680ef70532 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2310,9 +2310,10 @@ static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task)
 }
 
 static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
-                                             uint64_t offset, uint64_t bytes,
+                                             int64_t offset, int64_t bytes,
                                              QEMUIOVector *qiov,
-                                             size_t qiov_offset, int flags)
+                                             size_t qiov_offset,
+                                             BdrvRequestFlags flags)
 {
     BDRVQcow2State *s = bs->opaque;
     int ret = 0;
diff --git a/block/quorum.c b/block/quorum.c
index f2c0805000..57c73b2156 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -663,8 +663,8 @@ static int read_fifo_child(QuorumAIOCB *acb)
     return ret;
 }
 
-static int quorum_co_preadv(BlockDriverState *bs, uint64_t offset,
-                            uint64_t bytes, QEMUIOVector *qiov, int flags)
+static int quorum_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                            QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVQuorumState *s = bs->opaque;
     QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes, flags);
diff --git a/block/raw-format.c b/block/raw-format.c
index c26f493688..a5728e7b0c 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -181,8 +181,8 @@ static void raw_reopen_abort(BDRVReopenState *state)
 }
 
 /* Check and adjust the offset, against 'offset' and 'size' options. */
-static inline int raw_adjust_offset(BlockDriverState *bs, uint64_t *offset,
-                                    uint64_t bytes, bool is_write)
+static inline int raw_adjust_offset(BlockDriverState *bs, int64_t *offset,
+                                    int64_t bytes, bool is_write)
 {
     BDRVRawState *s = bs->opaque;
 
@@ -201,9 +201,9 @@ static inline int raw_adjust_offset(BlockDriverState *bs, uint64_t *offset,
     return 0;
 }
 
-static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
-                                      uint64_t bytes, QEMUIOVector *qiov,
-                                      int flags)
+static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes, QEMUIOVector *qiov,
+                                      BdrvRequestFlags flags)
 {
     int ret;
 
@@ -259,7 +259,7 @@ static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
         qiov = &local_qiov;
     }
 
-    ret = raw_adjust_offset(bs, &offset, bytes, true);
+    ret = raw_adjust_offset(bs, (int64_t *)&offset, bytes, true);
     if (ret) {
         goto fail;
     }
@@ -294,7 +294,7 @@ static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (uint64_t *)&offset, bytes, true);
+    ret = raw_adjust_offset(bs, &offset, bytes, true);
     if (ret) {
         return ret;
     }
@@ -306,7 +306,7 @@ static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (uint64_t *)&offset, bytes, true);
+    ret = raw_adjust_offset(bs, &offset, bytes, true);
     if (ret) {
         return ret;
     }
@@ -541,7 +541,7 @@ static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, &src_offset, bytes, false);
+    ret = raw_adjust_offset(bs, (int64_t *)&src_offset, bytes, false);
     if (ret) {
         return ret;
     }
@@ -560,7 +560,7 @@ static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
+    ret = raw_adjust_offset(bs, (int64_t *)&dst_offset, bytes, true);
     if (ret) {
         return ret;
     }
diff --git a/block/rbd.c b/block/rbd.c
index dcf82b15b8..21438dfb7c 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1164,9 +1164,9 @@ static int coroutine_fn qemu_rbd_start_co(BlockDriverState *bs,
 }
 
 static int
-coroutine_fn qemu_rbd_co_preadv(BlockDriverState *bs, uint64_t offset,
-                               uint64_t bytes, QEMUIOVector *qiov,
-                               int flags)
+coroutine_fn qemu_rbd_co_preadv(BlockDriverState *bs, int64_t offset,
+                                int64_t bytes, QEMUIOVector *qiov,
+                                BdrvRequestFlags flags)
 {
     return qemu_rbd_start_co(bs, offset, bytes, qiov, flags, RBD_AIO_READ);
 }
diff --git a/block/throttle.c b/block/throttle.c
index b685166ad4..20362b5fe5 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -112,8 +112,9 @@ static int64_t throttle_getlength(BlockDriverState *bs)
 }
 
 static int coroutine_fn throttle_co_preadv(BlockDriverState *bs,
-                                           uint64_t offset, uint64_t bytes,
-                                           QEMUIOVector *qiov, int flags)
+                                           int64_t offset, int64_t bytes,
+                                           QEMUIOVector *qiov,
+                                           BdrvRequestFlags flags)
 {
 
     ThrottleGroupMember *tgm = bs->opaque;
diff --git a/block/vdi.c b/block/vdi.c
index 548f8a057b..b394cf6ca6 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -544,8 +544,8 @@ static int coroutine_fn vdi_co_block_status(BlockDriverState *bs,
 }
 
 static int coroutine_fn
-vdi_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-              QEMUIOVector *qiov, int flags)
+vdi_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+              QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVVdiState *s = bs->opaque;
     QEMUIOVector local_qiov;
diff --git a/block/vmdk.c b/block/vmdk.c
index 4499f136bd..78592160d0 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1888,8 +1888,8 @@ static int vmdk_read_extent(VmdkExtent *extent, int64_t cluster_offset,
 }
 
 static int coroutine_fn
-vmdk_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-               QEMUIOVector *qiov, int flags)
+vmdk_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+               QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVVmdkState *s = bs->opaque;
     int ret;
diff --git a/block/vpc.c b/block/vpc.c
index 17a705b482..29c8517ff8 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -608,8 +608,8 @@ static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 }
 
 static int coroutine_fn
-vpc_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-              QEMUIOVector *qiov, int flags)
+vpc_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+              QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVVPCState *s = bs->opaque;
     int ret;
diff --git a/block/vvfat.c b/block/vvfat.c
index 34bf1e3a86..9c53c2d0a4 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1522,8 +1522,8 @@ static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
 }
 
 static int coroutine_fn
-vvfat_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                QEMUIOVector *qiov, int flags)
+vvfat_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int ret;
     BDRVVVFATState *s = bs->opaque;
diff --git a/include/block/block_int.h b/include/block/block_int.h
index ed60495938..9b1a276fa1 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -235,8 +235,8 @@ struct BlockDriver {
 
     /* aio */
     BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
-        BlockCompletionFunc *cb, void *opaque);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+        BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
     BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
         BlockCompletionFunc *cb, void *opaque);
@@ -265,10 +265,11 @@ struct BlockDriver {
      * The buffer in @qiov may point directly to guest memory.
      */
     int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+        BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes,
-        QEMUIOVector *qiov, size_t qiov_offset, int flags);
+        int64_t offset, int64_t bytes,
+        QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
     /**
diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c
index ce071b5fc5..2d3c17e566 100644
--- a/tests/unit/test-bdrv-drain.c
+++ b/tests/unit/test-bdrv-drain.c
@@ -65,8 +65,9 @@ static void co_reenter_bh(void *opaque)
 }
 
 static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
-                                            uint64_t offset, uint64_t bytes,
-                                            QEMUIOVector *qiov, int flags)
+                                            int64_t offset, int64_t bytes,
+                                            QEMUIOVector *qiov,
+                                            BdrvRequestFlags flags)
 {
     BDRVTestState *s = bs->opaque;
 
@@ -1106,8 +1107,9 @@ static void bdrv_test_top_close(BlockDriverState *bs)
 }
 
 static int coroutine_fn bdrv_test_top_co_preadv(BlockDriverState *bs,
-                                                uint64_t offset, uint64_t bytes,
-                                                QEMUIOVector *qiov, int flags)
+                                                int64_t offset, int64_t bytes,
+                                                QEMUIOVector *qiov,
+                                                BdrvRequestFlags flags)
 {
     BDRVTestTopState *tts = bs->opaque;
     return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags);
@@ -1855,10 +1857,10 @@ static void bdrv_replace_test_close(BlockDriverState *bs)
  *   Set .has_read to true and return success.
  */
 static int coroutine_fn bdrv_replace_test_co_preadv(BlockDriverState *bs,
-                                                    uint64_t offset,
-                                                    uint64_t bytes,
+                                                    int64_t offset,
+                                                    int64_t bytes,
                                                     QEMUIOVector *qiov,
-                                                    int flags)
+                                                    BdrvRequestFlags flags)
 {
     BDRVReplaceTestState *s = bs->opaque;
 
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index c39e70b2f5..f18fa6e0fb 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -31,9 +31,18 @@
 #include "qemu/main-loop.h"
 #include "iothread.h"
 
-static int coroutine_fn bdrv_test_co_prwv(BlockDriverState *bs,
-                                          uint64_t offset, uint64_t bytes,
-                                          QEMUIOVector *qiov, int flags)
+static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
+                                            int64_t offset, int64_t bytes,
+                                            QEMUIOVector *qiov,
+                                            BdrvRequestFlags flags)
+{
+    return 0;
+}
+
+static int coroutine_fn bdrv_test_co_pwritev(BlockDriverState *bs,
+                                             uint64_t offset, uint64_t bytes,
+                                             QEMUIOVector *qiov,
+                                             int flags)
 {
     return 0;
 }
@@ -66,8 +75,8 @@ static BlockDriver bdrv_test = {
     .format_name            = "test",
     .instance_size          = 1,
 
-    .bdrv_co_preadv         = bdrv_test_co_prwv,
-    .bdrv_co_pwritev        = bdrv_test_co_prwv,
+    .bdrv_co_preadv         = bdrv_test_co_preadv,
+    .bdrv_co_pwritev        = bdrv_test_co_pwritev,
     .bdrv_co_pdiscard       = bdrv_test_co_pdiscard,
     .bdrv_co_truncate       = bdrv_test_co_truncate,
     .bdrv_co_block_status   = bdrv_test_co_block_status,

From e75abedab7e10043ed81b1cbc3033409aff0159e Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:00 +0300
Subject: [PATCH 05/19] block: use int64_t instead of uint64_t in driver write
 handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver write handlers parameters which are already 64bit to
signed type.

While being here, convert also flags parameter to be BdrvRequestFlags.

Now let's consider all callers. Simple

  git grep '\->bdrv_\(aio\|co\)_pwritev\(_part\)\?'

shows that's there three callers of driver function:

 bdrv_driver_pwritev() and bdrv_driver_pwritev_compressed() in
 block/io.c, both pass int64_t, checked by bdrv_check_qiov_request() to
 be non-negative.

 qcow2_save_vmstate() does bdrv_check_qiov_request().

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_\(aio\|co\)_pwritev\(_part\)\?\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

shows several callers:

qcow2:
  qcow2_co_truncate() write at most up to @offset, which is checked in
    generic qcow2_co_truncate() by bdrv_check_request().
  qcow2_co_pwritev_compressed_task() pass the request (or part of the
    request) that already went through normal write path, so it should
    be OK

qcow:
  qcow_co_pwritev_compressed() pass int64_t, it's updated by this patch

quorum:
  quorum_co_pwrite_zeroes() pass int64_t and int - OK

throttle:
  throttle_co_pwritev_compressed() pass int64_t, it's updated by this
  patch

vmdk:
  vmdk_co_pwritev_compressed() pass int64_t, it's updated by this
  patch

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/blkdebug.c                 |  4 ++--
 block/blklogwrites.c             |  4 ++--
 block/blkreplay.c                |  2 +-
 block/blkverify.c                |  4 ++--
 block/copy-before-write.c        |  7 ++++---
 block/copy-on-read.c             | 11 ++++++-----
 block/crypto.c                   |  4 ++--
 block/file-posix.c               |  6 +++---
 block/file-win32.c               |  4 ++--
 block/filter-compress.c          |  7 ++++---
 block/io.c                       |  6 ++++--
 block/mirror.c                   |  2 +-
 block/nbd.c                      |  5 +++--
 block/nfs.c                      |  6 +++---
 block/null.c                     |  9 +++++----
 block/nvme.c                     |  5 +++--
 block/preallocate.c              |  6 +++---
 block/qcow.c                     | 10 +++++-----
 block/qcow2.c                    |  6 +++---
 block/quorum.c                   |  5 +++--
 block/raw-format.c               |  8 ++++----
 block/rbd.c                      |  6 +++---
 block/throttle.c                 |  9 +++++----
 block/trace-events               |  2 +-
 block/vdi.c                      |  4 ++--
 block/vmdk.c                     |  8 ++++----
 block/vpc.c                      |  4 ++--
 block/vvfat.c                    |  4 ++--
 include/block/block_int.h        | 16 ++++++++--------
 tests/unit/test-block-iothread.c |  4 ++--
 30 files changed, 94 insertions(+), 84 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 12b8419065..e686cd9799 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -652,8 +652,8 @@ blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn
-blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                    QEMUIOVector *qiov, int flags)
+blkdebug_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                    QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int err;
 
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index de3d4ba2b6..ca174ab135 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -460,8 +460,8 @@ blk_log_writes_co_do_file_pdiscard(BlkLogWritesFileReq *fr)
 }
 
 static int coroutine_fn
-blk_log_writes_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                          QEMUIOVector *qiov, int flags)
+blk_log_writes_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                          QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     return blk_log_writes_co_log(bs, offset, bytes, qiov, flags,
                                  blk_log_writes_co_do_file_pwritev, 0, false);
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 13ea2166bb..7ba62dcac1 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -83,7 +83,7 @@ static int coroutine_fn blkreplay_co_preadv(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkreplay_co_pwritev(BlockDriverState *bs,
-    uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
diff --git a/block/blkverify.c b/block/blkverify.c
index 5e35744b8a..d1facf5ba9 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -250,8 +250,8 @@ blkverify_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn
-blkverify_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                     QEMUIOVector *qiov, int flags)
+blkverify_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                     QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BlkverifyRequest r;
     return blkverify_co_prwv(bs, &r, offset, bytes, qiov, qiov, flags, true);
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 591cc3ac75..74360b4853 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -86,9 +86,10 @@ static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs,
-                                       uint64_t offset,
-                                       uint64_t bytes,
-                                       QEMUIOVector *qiov, int flags)
+                                       int64_t offset,
+                                       int64_t bytes,
+                                       QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     int ret = cbw_do_copy_before_write(bs, offset, bytes, flags);
     if (ret < 0) {
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index d34add4476..b2ec36b6fc 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -181,10 +181,11 @@ static int coroutine_fn cor_co_preadv_part(BlockDriverState *bs,
 
 
 static int coroutine_fn cor_co_pwritev_part(BlockDriverState *bs,
-                                            uint64_t offset,
-                                            uint64_t bytes,
+                                            int64_t offset,
+                                            int64_t bytes,
                                             QEMUIOVector *qiov,
-                                            size_t qiov_offset, int flags)
+                                            size_t qiov_offset,
+                                            BdrvRequestFlags flags)
 {
     return bdrv_co_pwritev_part(bs->file, offset, bytes, qiov, qiov_offset,
                                 flags);
@@ -207,8 +208,8 @@ static int coroutine_fn cor_co_pdiscard(BlockDriverState *bs,
 
 
 static int coroutine_fn cor_co_pwritev_compressed(BlockDriverState *bs,
-                                                  uint64_t offset,
-                                                  uint64_t bytes,
+                                                  int64_t offset,
+                                                  int64_t bytes,
                                                   QEMUIOVector *qiov)
 {
     return bdrv_co_pwritev(bs->file, offset, bytes, qiov,
diff --git a/block/crypto.c b/block/crypto.c
index a732a36d10..c8ba4681e2 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -460,8 +460,8 @@ block_crypto_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 
 
 static coroutine_fn int
-block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                        QEMUIOVector *qiov, int flags)
+block_crypto_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                        QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BlockCrypto *crypto = bs->opaque;
     uint64_t cur_bytes; /* number of bytes in current iteration */
diff --git a/block/file-posix.c b/block/file-posix.c
index df4a67f8b2..994f1c26ca 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2084,9 +2084,9 @@ static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset,
     return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_READ);
 }
 
-static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                       uint64_t bytes, QEMUIOVector *qiov,
-                                       int flags)
+static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                       int64_t bytes, QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     assert(flags == 0);
     return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_WRITE);
diff --git a/block/file-win32.c b/block/file-win32.c
index 4e8947009b..ec9d64d0e4 100644
--- a/block/file-win32.c
+++ b/block/file-win32.c
@@ -455,8 +455,8 @@ static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
 }
 
 static BlockAIOCB *raw_aio_pwritev(BlockDriverState *bs,
-                                   uint64_t offset, uint64_t bytes,
-                                   QEMUIOVector *qiov, int flags,
+                                   int64_t offset, int64_t bytes,
+                                   QEMUIOVector *qiov, BdrvRequestFlags flags,
                                    BlockCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
diff --git a/block/filter-compress.c b/block/filter-compress.c
index 54a16c6c64..505822a44f 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -74,10 +74,11 @@ static int coroutine_fn compress_co_preadv_part(BlockDriverState *bs,
 
 
 static int coroutine_fn compress_co_pwritev_part(BlockDriverState *bs,
-                                                 uint64_t offset,
-                                                 uint64_t bytes,
+                                                 int64_t offset,
+                                                 int64_t bytes,
                                                  QEMUIOVector *qiov,
-                                                 size_t qiov_offset, int flags)
+                                                 size_t qiov_offset,
+                                                 BdrvRequestFlags flags)
 {
     return bdrv_co_pwritev_part(bs->file, offset, bytes, qiov, qiov_offset,
                                 flags | BDRV_REQ_WRITE_COMPRESSED);
diff --git a/block/io.c b/block/io.c
index a4f124f755..aa6f7b075e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1230,7 +1230,8 @@ out:
 static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
                                             int64_t offset, int64_t bytes,
                                             QEMUIOVector *qiov,
-                                            size_t qiov_offset, int flags)
+                                            size_t qiov_offset,
+                                            BdrvRequestFlags flags)
 {
     BlockDriver *drv = bs->drv;
     int64_t sector_num;
@@ -2073,7 +2074,8 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, int64_t bytes,
  */
 static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
     BdrvTrackedRequest *req, int64_t offset, int64_t bytes,
-    int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags)
+    int64_t align, QEMUIOVector *qiov, size_t qiov_offset,
+    BdrvRequestFlags flags)
 {
     BlockDriverState *bs = child->bs;
     BlockDriver *drv = bs->drv;
diff --git a/block/mirror.c b/block/mirror.c
index e24d0aedd5..c4c623ceed 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1456,7 +1456,7 @@ out:
 }
 
 static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs,
-    uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     MirrorBDSOpaque *s = bs->opaque;
     QEMUIOVector bounce_qiov;
diff --git a/block/nbd.c b/block/nbd.c
index c816933d7d..caee396525 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1381,8 +1381,9 @@ static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset,
     return ret ? ret : request_ret;
 }
 
-static int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                 uint64_t bytes, QEMUIOVector *qiov, int flags)
+static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                 int64_t bytes, QEMUIOVector *qiov,
+                                 BdrvRequestFlags flags)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
     NBDRequest request = {
diff --git a/block/nfs.c b/block/nfs.c
index 27f9ab8307..577aea1d22 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -296,9 +296,9 @@ static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, int64_t offset,
     return 0;
 }
 
-static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                       uint64_t bytes, QEMUIOVector *iov,
-                                       int flags)
+static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                       int64_t bytes, QEMUIOVector *iov,
+                                       BdrvRequestFlags flags)
 {
     NFSClient *client = bs->opaque;
     NFSRPC task;
diff --git a/block/null.c b/block/null.c
index 343dbb580d..75f7d0db40 100644
--- a/block/null.c
+++ b/block/null.c
@@ -130,8 +130,9 @@ static coroutine_fn int null_co_preadv(BlockDriverState *bs,
 }
 
 static coroutine_fn int null_co_pwritev(BlockDriverState *bs,
-                                        uint64_t offset, uint64_t bytes,
-                                        QEMUIOVector *qiov, int flags)
+                                        int64_t offset, int64_t bytes,
+                                        QEMUIOVector *qiov,
+                                        BdrvRequestFlags flags)
 {
     return null_co_common(bs);
 }
@@ -203,8 +204,8 @@ static BlockAIOCB *null_aio_preadv(BlockDriverState *bs,
 }
 
 static BlockAIOCB *null_aio_pwritev(BlockDriverState *bs,
-                                    uint64_t offset, uint64_t bytes,
-                                    QEMUIOVector *qiov, int flags,
+                                    int64_t offset, int64_t bytes,
+                                    QEMUIOVector *qiov, BdrvRequestFlags flags,
                                     BlockCompletionFunc *cb,
                                     void *opaque)
 {
diff --git a/block/nvme.c b/block/nvme.c
index f812eb1cc2..c44db18939 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1259,8 +1259,9 @@ static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
 }
 
 static coroutine_fn int nvme_co_pwritev(BlockDriverState *bs,
-                                        uint64_t offset, uint64_t bytes,
-                                        QEMUIOVector *qiov, int flags)
+                                        int64_t offset, int64_t bytes,
+                                        QEMUIOVector *qiov,
+                                        BdrvRequestFlags flags)
 {
     return nvme_co_prw(bs, offset, bytes, qiov, true, flags);
 }
diff --git a/block/preallocate.c b/block/preallocate.c
index 5709443612..c19885af17 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -349,11 +349,11 @@ static int coroutine_fn preallocate_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static coroutine_fn int preallocate_co_pwritev_part(BlockDriverState *bs,
-                                                    uint64_t offset,
-                                                    uint64_t bytes,
+                                                    int64_t offset,
+                                                    int64_t bytes,
                                                     QEMUIOVector *qiov,
                                                     size_t qiov_offset,
-                                                    int flags)
+                                                    BdrvRequestFlags flags)
 {
     handle_write(bs, offset, bytes, false);
 
diff --git a/block/qcow.c b/block/qcow.c
index 1151b8d79b..c39940f33e 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -714,9 +714,9 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, int64_t offset,
     return ret;
 }
 
-static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                        uint64_t bytes, QEMUIOVector *qiov,
-                                        int flags)
+static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                        int64_t bytes, QEMUIOVector *qiov,
+                                        BdrvRequestFlags flags)
 {
     BDRVQcowState *s = bs->opaque;
     int offset_in_cluster;
@@ -1047,8 +1047,8 @@ static int qcow_make_empty(BlockDriverState *bs)
 /* XXX: put compressed sectors first, then all the cluster aligned
    tables to avoid losing bytes in alignment */
 static coroutine_fn int
-qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
-                           uint64_t bytes, QEMUIOVector *qiov)
+qcow_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                           QEMUIOVector *qiov)
 {
     BDRVQcowState *s = bs->opaque;
     z_stream strm;
diff --git a/block/qcow2.c b/block/qcow2.c
index 680ef70532..bb5455ed3d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2597,8 +2597,8 @@ static coroutine_fn int qcow2_co_pwritev_task_entry(AioTask *task)
 }
 
 static coroutine_fn int qcow2_co_pwritev_part(
-        BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-        QEMUIOVector *qiov, size_t qiov_offset, int flags)
+        BlockDriverState *bs, int64_t offset, int64_t bytes,
+        QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags)
 {
     BDRVQcow2State *s = bs->opaque;
     int offset_in_cluster;
@@ -4631,7 +4631,7 @@ static coroutine_fn int qcow2_co_pwritev_compressed_task_entry(AioTask *task)
  */
 static coroutine_fn int
 qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
-                                 uint64_t offset, uint64_t bytes,
+                                 int64_t offset, int64_t bytes,
                                  QEMUIOVector *qiov, size_t qiov_offset)
 {
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/quorum.c b/block/quorum.c
index 57c73b2156..f4b76ea010 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -714,8 +714,9 @@ static void write_quorum_entry(void *opaque)
     }
 }
 
-static int quorum_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                             uint64_t bytes, QEMUIOVector *qiov, int flags)
+static int quorum_co_pwritev(BlockDriverState *bs, int64_t offset,
+                             int64_t bytes, QEMUIOVector *qiov,
+                             BdrvRequestFlags flags)
 {
     BDRVQuorumState *s = bs->opaque;
     QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes, flags);
diff --git a/block/raw-format.c b/block/raw-format.c
index a5728e7b0c..d223298dfc 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -216,9 +216,9 @@ static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset,
     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 }
 
-static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                       uint64_t bytes, QEMUIOVector *qiov,
-                                       int flags)
+static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                       int64_t bytes, QEMUIOVector *qiov,
+                                       BdrvRequestFlags flags)
 {
     void *buf = NULL;
     BlockDriver *drv;
@@ -259,7 +259,7 @@ static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
         qiov = &local_qiov;
     }
 
-    ret = raw_adjust_offset(bs, (int64_t *)&offset, bytes, true);
+    ret = raw_adjust_offset(bs, &offset, bytes, true);
     if (ret) {
         goto fail;
     }
diff --git a/block/rbd.c b/block/rbd.c
index 21438dfb7c..efc0835ee7 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1172,9 +1172,9 @@ coroutine_fn qemu_rbd_co_preadv(BlockDriverState *bs, int64_t offset,
 }
 
 static int
-coroutine_fn qemu_rbd_co_pwritev(BlockDriverState *bs, uint64_t offset,
-                                 uint64_t bytes, QEMUIOVector *qiov,
-                                 int flags)
+coroutine_fn qemu_rbd_co_pwritev(BlockDriverState *bs, int64_t offset,
+                                 int64_t bytes, QEMUIOVector *qiov,
+                                 BdrvRequestFlags flags)
 {
     BDRVRBDState *s = bs->opaque;
     /*
diff --git a/block/throttle.c b/block/throttle.c
index 20362b5fe5..1330e844c3 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -124,8 +124,9 @@ static int coroutine_fn throttle_co_preadv(BlockDriverState *bs,
 }
 
 static int coroutine_fn throttle_co_pwritev(BlockDriverState *bs,
-                                            uint64_t offset, uint64_t bytes,
-                                            QEMUIOVector *qiov, int flags)
+                                            int64_t offset, int64_t bytes,
+                                            QEMUIOVector *qiov,
+                                            BdrvRequestFlags flags)
 {
     ThrottleGroupMember *tgm = bs->opaque;
     throttle_group_co_io_limits_intercept(tgm, bytes, true);
@@ -153,8 +154,8 @@ static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs,
 }
 
 static int coroutine_fn throttle_co_pwritev_compressed(BlockDriverState *bs,
-                                                       uint64_t offset,
-                                                       uint64_t bytes,
+                                                       int64_t offset,
+                                                       int64_t bytes,
                                                        QEMUIOVector *qiov)
 {
     return throttle_co_pwritev(bs, offset, bytes, qiov,
diff --git a/block/trace-events b/block/trace-events
index f4f1267c8c..983dd54830 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -75,7 +75,7 @@ luring_resubmit_short_read(void *s, void *luringcb, int nread) "LuringState %p l
 
 # qcow2.c
 qcow2_add_task(void *co, void *bs, void *pool, const char *action, int cluster_type, uint64_t host_offset, uint64_t offset, uint64_t bytes, void *qiov, size_t qiov_offset) "co %p bs %p pool %p: %s: cluster_type %d file_cluster_offset %" PRIu64 " offset %" PRIu64 " bytes %" PRIu64 " qiov %p qiov_offset %zu"
-qcow2_writev_start_req(void *co, int64_t offset, int bytes) "co %p offset 0x%" PRIx64 " bytes %d"
+qcow2_writev_start_req(void *co, int64_t offset, int64_t bytes) "co %p offset 0x%" PRIx64 " bytes %" PRId64
 qcow2_writev_done_req(void *co, int ret) "co %p ret %d"
 qcow2_writev_start_part(void *co) "co %p"
 qcow2_writev_done_part(void *co, int cur_bytes) "co %p cur_bytes %d"
diff --git a/block/vdi.c b/block/vdi.c
index b394cf6ca6..bdc58d726e 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -600,8 +600,8 @@ vdi_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn
-vdi_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-               QEMUIOVector *qiov, int flags)
+vdi_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+               QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVVdiState *s = bs->opaque;
     QEMUIOVector local_qiov;
diff --git a/block/vmdk.c b/block/vmdk.c
index 78592160d0..8d49e54bdd 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2068,8 +2068,8 @@ static int vmdk_pwritev(BlockDriverState *bs, uint64_t offset,
 }
 
 static int coroutine_fn
-vmdk_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                QEMUIOVector *qiov, int flags)
+vmdk_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int ret;
     BDRVVmdkState *s = bs->opaque;
@@ -2080,8 +2080,8 @@ vmdk_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 }
 
 static int coroutine_fn
-vmdk_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
-                           uint64_t bytes, QEMUIOVector *qiov)
+vmdk_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                           QEMUIOVector *qiov)
 {
     if (bytes == 0) {
         /* The caller will write bytes 0 to signal EOF.
diff --git a/block/vpc.c b/block/vpc.c
index 29c8517ff8..1b4c7333af 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -658,8 +658,8 @@ fail:
 }
 
 static int coroutine_fn
-vpc_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-               QEMUIOVector *qiov, int flags)
+vpc_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+               QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     BDRVVPCState *s = bs->opaque;
     int64_t image_offset;
diff --git a/block/vvfat.c b/block/vvfat.c
index 9c53c2d0a4..05e78e3c27 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3061,8 +3061,8 @@ DLOG(checkpoint());
 }
 
 static int coroutine_fn
-vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
-                 QEMUIOVector *qiov, int flags)
+vvfat_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                 QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int ret;
     BDRVVVFATState *s = bs->opaque;
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 9b1a276fa1..2cf5f1722a 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -238,8 +238,8 @@ struct BlockDriver {
         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
         BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
     BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
-        BlockCompletionFunc *cb, void *opaque);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+        BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
         BlockCompletionFunc *cb, void *opaque);
     BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
@@ -288,10 +288,11 @@ struct BlockDriver {
      * The buffer in @qiov may point directly to guest memory.
      */
     int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+        BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes,
-        QEMUIOVector *qiov, size_t qiov_offset, int flags);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset,
+        BdrvRequestFlags flags);
 
     /*
      * Efficiently zero a region of the disk image.  Typically an image format
@@ -438,10 +439,9 @@ struct BlockDriver {
                                       Error **errp);
 
     int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov);
     int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs,
-        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
-        size_t qiov_offset);
+        int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset);
 
     int (*bdrv_snapshot_create)(BlockDriverState *bs,
                                 QEMUSnapshotInfo *sn_info);
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index f18fa6e0fb..c86954c7ba 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -40,9 +40,9 @@ static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
 }
 
 static int coroutine_fn bdrv_test_co_pwritev(BlockDriverState *bs,
-                                             uint64_t offset, uint64_t bytes,
+                                             int64_t offset, int64_t bytes,
                                              QEMUIOVector *qiov,
-                                             int flags)
+                                             BdrvRequestFlags flags)
 {
     return 0;
 }

From 485350497b7a9be3477d453fe0fdf380b8535303 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:01 +0300
Subject: [PATCH 06/19] block: use int64_t instead of uint64_t in copy_range
 driver handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver copy_range handlers parameters which are already
64bit to signed type.

Now let's consider all callers. Simple

  git grep '\->bdrv_co_copy_range'

shows the only caller:

  bdrv_co_copy_range_internal(), which does bdrv_check_request32(),
  so everything is OK.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_co_copy_range_\(from\|to\)\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

shows no more callers. So, we are done.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/file-posix.c        | 10 +++++-----
 block/iscsi.c             | 12 ++++++------
 block/qcow2.c             | 12 ++++++------
 block/raw-format.c        | 16 ++++++++--------
 include/block/block_int.h | 12 ++++++------
 5 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 994f1c26ca..ed71e8d2df 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -3203,8 +3203,8 @@ static void raw_abort_perm_update(BlockDriverState *bs)
 }
 
 static int coroutine_fn raw_co_copy_range_from(
-        BlockDriverState *bs, BdrvChild *src, uint64_t src_offset,
-        BdrvChild *dst, uint64_t dst_offset, uint64_t bytes,
+        BlockDriverState *bs, BdrvChild *src, int64_t src_offset,
+        BdrvChild *dst, int64_t dst_offset, int64_t bytes,
         BdrvRequestFlags read_flags, BdrvRequestFlags write_flags)
 {
     return bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes,
@@ -3213,10 +3213,10 @@ static int coroutine_fn raw_co_copy_range_from(
 
 static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
                                              BdrvChild *src,
-                                             uint64_t src_offset,
+                                             int64_t src_offset,
                                              BdrvChild *dst,
-                                             uint64_t dst_offset,
-                                             uint64_t bytes,
+                                             int64_t dst_offset,
+                                             int64_t bytes,
                                              BdrvRequestFlags read_flags,
                                              BdrvRequestFlags write_flags)
 {
diff --git a/block/iscsi.c b/block/iscsi.c
index 852384086b..01fdd1775f 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -2169,10 +2169,10 @@ static void coroutine_fn iscsi_co_invalidate_cache(BlockDriverState *bs,
 
 static int coroutine_fn iscsi_co_copy_range_from(BlockDriverState *bs,
                                                  BdrvChild *src,
-                                                 uint64_t src_offset,
+                                                 int64_t src_offset,
                                                  BdrvChild *dst,
-                                                 uint64_t dst_offset,
-                                                 uint64_t bytes,
+                                                 int64_t dst_offset,
+                                                 int64_t bytes,
                                                  BdrvRequestFlags read_flags,
                                                  BdrvRequestFlags write_flags)
 {
@@ -2310,10 +2310,10 @@ static void iscsi_xcopy_data(struct iscsi_data *data,
 
 static int coroutine_fn iscsi_co_copy_range_to(BlockDriverState *bs,
                                                BdrvChild *src,
-                                               uint64_t src_offset,
+                                               int64_t src_offset,
                                                BdrvChild *dst,
-                                               uint64_t dst_offset,
-                                               uint64_t bytes,
+                                               int64_t dst_offset,
+                                               int64_t bytes,
                                                BdrvRequestFlags read_flags,
                                                BdrvRequestFlags write_flags)
 {
diff --git a/block/qcow2.c b/block/qcow2.c
index bb5455ed3d..520ae37a29 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -4026,9 +4026,9 @@ static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
 
 static int coroutine_fn
 qcow2_co_copy_range_from(BlockDriverState *bs,
-                         BdrvChild *src, uint64_t src_offset,
-                         BdrvChild *dst, uint64_t dst_offset,
-                         uint64_t bytes, BdrvRequestFlags read_flags,
+                         BdrvChild *src, int64_t src_offset,
+                         BdrvChild *dst, int64_t dst_offset,
+                         int64_t bytes, BdrvRequestFlags read_flags,
                          BdrvRequestFlags write_flags)
 {
     BDRVQcow2State *s = bs->opaque;
@@ -4109,9 +4109,9 @@ out:
 
 static int coroutine_fn
 qcow2_co_copy_range_to(BlockDriverState *bs,
-                       BdrvChild *src, uint64_t src_offset,
-                       BdrvChild *dst, uint64_t dst_offset,
-                       uint64_t bytes, BdrvRequestFlags read_flags,
+                       BdrvChild *src, int64_t src_offset,
+                       BdrvChild *dst, int64_t dst_offset,
+                       int64_t bytes, BdrvRequestFlags read_flags,
                        BdrvRequestFlags write_flags)
 {
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/raw-format.c b/block/raw-format.c
index d223298dfc..345137813e 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -532,16 +532,16 @@ static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
 
 static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
                                                BdrvChild *src,
-                                               uint64_t src_offset,
+                                               int64_t src_offset,
                                                BdrvChild *dst,
-                                               uint64_t dst_offset,
-                                               uint64_t bytes,
+                                               int64_t dst_offset,
+                                               int64_t bytes,
                                                BdrvRequestFlags read_flags,
                                                BdrvRequestFlags write_flags)
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (int64_t *)&src_offset, bytes, false);
+    ret = raw_adjust_offset(bs, &src_offset, bytes, false);
     if (ret) {
         return ret;
     }
@@ -551,16 +551,16 @@ static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
 
 static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
                                              BdrvChild *src,
-                                             uint64_t src_offset,
+                                             int64_t src_offset,
                                              BdrvChild *dst,
-                                             uint64_t dst_offset,
-                                             uint64_t bytes,
+                                             int64_t dst_offset,
+                                             int64_t bytes,
                                              BdrvRequestFlags read_flags,
                                              BdrvRequestFlags write_flags)
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (int64_t *)&dst_offset, bytes, true);
+    ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
     if (ret) {
         return ret;
     }
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 2cf5f1722a..5536f49bc6 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -314,10 +314,10 @@ struct BlockDriver {
      */
     int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
                                                 BdrvChild *src,
-                                                uint64_t offset,
+                                                int64_t offset,
                                                 BdrvChild *dst,
-                                                uint64_t dst_offset,
-                                                uint64_t bytes,
+                                                int64_t dst_offset,
+                                                int64_t bytes,
                                                 BdrvRequestFlags read_flags,
                                                 BdrvRequestFlags write_flags);
 
@@ -331,10 +331,10 @@ struct BlockDriver {
      */
     int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
                                               BdrvChild *src,
-                                              uint64_t src_offset,
+                                              int64_t src_offset,
                                               BdrvChild *dst,
-                                              uint64_t dst_offset,
-                                              uint64_t bytes,
+                                              int64_t dst_offset,
+                                              int64_t bytes,
                                               BdrvRequestFlags read_flags,
                                               BdrvRequestFlags write_flags);
 

From d544f5d3b1df79d71eae4d7fac528f65d22265ad Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:02 +0300
Subject: [PATCH 07/19] block: make BlockLimits::max_pwrite_zeroes 64bit

We are going to support 64 bit write-zeroes requests. Now update the
limit variable. It's absolutely safe. The variable is set in some
drivers, and used in bdrv_co_do_pwrite_zeroes().

Update also max_write_zeroes variable in bdrv_co_do_pwrite_zeroes(), so
that bdrv_co_do_pwrite_zeroes() is now prepared to 64bit requests. The
remaining logic including num, offset and bytes variables is already
supporting 64bit requests.

So the only thing that prevents 64 bit requests is limiting
max_write_zeroes variable to INT_MAX in bdrv_co_do_pwrite_zeroes().
We'll drop this limitation after updating all block drivers.

Ah, we also have bdrv_check_request32() in bdrv_co_pwritev_part(). It
will be modified to do bdrv_check_request() for write-zeroes path.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-7-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c                | 2 +-
 include/block/block_int.h | 9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/block/io.c b/block/io.c
index aa6f7b075e..0090224603 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1869,7 +1869,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int head = 0;
     int tail = 0;
 
-    int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
+    int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
     int alignment = MAX(bs->bl.pwrite_zeroes_alignment,
                         bs->bl.request_alignment);
     int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5536f49bc6..24958acd33 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -686,10 +686,11 @@ typedef struct BlockLimits {
      * that is set. May be 0 if bl.request_alignment is good enough */
     uint32_t pdiscard_alignment;
 
-    /* Maximum number of bytes that can zeroized at once (since it is
-     * signed, it must be < 2G, if set). Must be multiple of
-     * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
-    int32_t max_pwrite_zeroes;
+    /*
+     * Maximum number of bytes that can zeroized at once. Must be multiple of
+     * pwrite_zeroes_alignment. 0 means no limit.
+     */
+    int64_t max_pwrite_zeroes;
 
     /* Optimal alignment for write zeroes requests in bytes. A power
      * of 2 is best but not mandatory.  Must be a multiple of

From f34b2bcf8c393929c7d2100eb2f3909cac0d1cab Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:03 +0300
Subject: [PATCH 08/19] block: use int64_t instead of int in driver
 write_zeroes handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver write_zeroes handlers bytes parameter to int64_t.

The only caller of all updated function is bdrv_co_do_pwrite_zeroes().

bdrv_co_do_pwrite_zeroes() itself is of course OK with widening of
callee parameter type. Also, bdrv_co_do_pwrite_zeroes()'s
max_write_zeroes is limited to INT_MAX. So, updated functions all are
safe, they will not get "bytes" larger than before.

Still, let's look through all updated functions, and add assertions to
the ones which are actually unprepared to values larger than INT_MAX.
For these drivers also set explicit max_pwrite_zeroes limit.

Let's go:

blkdebug: calculations can't overflow, thanks to
  bdrv_check_qiov_request() in generic layer. rule_check() and
  bdrv_co_pwrite_zeroes() both have 64bit argument.

blklogwrites: pass to blk_log_writes_co_log() with 64bit argument.

blkreplay, copy-on-read, filter-compress: pass to
  bdrv_co_pwrite_zeroes() which is OK

copy-before-write: Calls cbw_do_copy_before_write() and
  bdrv_co_pwrite_zeroes, both have 64bit argument.

file-posix: both handler calls raw_do_pwrite_zeroes, which is updated.
  In raw_do_pwrite_zeroes() calculations are OK due to
  bdrv_check_qiov_request(), bytes go to RawPosixAIOData::aio_nbytes
  which is uint64_t.
  Check also where that uint64_t gets handed:
  handle_aiocb_write_zeroes_block() passes a uint64_t[2] to
  ioctl(BLKZEROOUT), handle_aiocb_write_zeroes() calls do_fallocate()
  which takes off_t (and we compile to always have 64-bit off_t), as
  does handle_aiocb_write_zeroes_unmap. All look safe.

gluster: bytes go to GlusterAIOCB::size which is int64_t and to
  glfs_zerofill_async works with off_t.

iscsi: Aha, here we deal with iscsi_writesame16_task() that has
  uint32_t num_blocks argument and iscsi_writesame16_task() has
  uint16_t argument. Make comments, add assertions and clarify
  max_pwrite_zeroes calculation.
  iscsi_allocmap_() functions already has int64_t argument
  is_byte_request_lun_aligned is simple to update, do it.

mirror_top: pass to bdrv_mirror_top_do_write which has uint64_t
  argument

nbd: Aha, here we have protocol limitation, and NBDRequest::len is
  uint32_t. max_pwrite_zeroes is cleanly set to 32bit value, so we are
  OK for now.

nvme: Again, protocol limitation. And no inherent limit for
  write-zeroes at all. But from code that calculates cdw12 it's obvious
  that we do have limit and alignment. Let's clarify it. Also,
  obviously the code is not prepared to handle bytes=0. Let's handle
  this case too.
  trace events already 64bit

preallocate: pass to handle_write() and bdrv_co_pwrite_zeroes(), both
  64bit.

rbd: pass to qemu_rbd_start_co() which is 64bit.

qcow2: offset + bytes and alignment still works good (thanks to
  bdrv_check_qiov_request()), so tail calculation is OK
  qcow2_subcluster_zeroize() has 64bit argument, should be OK
  trace events updated

qed: qed_co_request wants int nb_sectors. Also in code we have size_t
  used for request length which may be 32bit. So, let's just keep
  INT_MAX as a limit (aligning it down to pwrite_zeroes_alignment) and
  don't care.

raw-format: Is OK. raw_adjust_offset and bdrv_co_pwrite_zeroes are both
  64bit.

throttle: Both throttle_group_co_io_limits_intercept() and
  bdrv_co_pwrite_zeroes() are 64bit.

vmdk: pass to vmdk_pwritev which is 64bit

quorum: pass to quorum_co_pwritev() which is 64bit

Hooray!

At this point all block drivers are prepared to support 64bit
write-zero requests, or have explicitly set max_pwrite_zeroes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-8-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: use <= rather than < in assertions relying on max_pwrite_zeroes]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/blkdebug.c          |  2 +-
 block/blklogwrites.c      |  4 ++--
 block/blkreplay.c         |  2 +-
 block/copy-before-write.c |  2 +-
 block/copy-on-read.c      |  2 +-
 block/file-posix.c        |  6 +++---
 block/filter-compress.c   |  2 +-
 block/gluster.c           |  6 +++---
 block/iscsi.c             | 30 ++++++++++++++++++++----------
 block/mirror.c            |  2 +-
 block/nbd.c               |  6 ++++--
 block/nvme.c              | 24 +++++++++++++++++++++---
 block/preallocate.c       |  2 +-
 block/qcow2.c             |  2 +-
 block/qed.c               |  9 ++++++++-
 block/quorum.c            |  2 +-
 block/raw-format.c        |  2 +-
 block/rbd.c               |  4 ++--
 block/throttle.c          |  2 +-
 block/trace-events        |  4 ++--
 block/vmdk.c              |  2 +-
 include/block/block_int.h |  2 +-
 22 files changed, 78 insertions(+), 41 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index e686cd9799..742b4a3834 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -684,7 +684,7 @@ static int blkdebug_co_flush(BlockDriverState *bs)
 }
 
 static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
-                                                  int64_t offset, int bytes,
+                                                  int64_t offset, int64_t bytes,
                                                   BdrvRequestFlags flags)
 {
     uint32_t align = MAX(bs->bl.request_alignment,
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index ca174ab135..d7ae64c22d 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -468,8 +468,8 @@ blk_log_writes_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn
-blk_log_writes_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
-                                BdrvRequestFlags flags)
+blk_log_writes_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
+                                int64_t bytes, BdrvRequestFlags flags)
 {
     return blk_log_writes_co_log(bs, offset, bytes, NULL, flags,
                                  blk_log_writes_co_do_file_pwrite_zeroes, 0,
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 7ba62dcac1..89d74a3cca 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -94,7 +94,7 @@ static int coroutine_fn blkreplay_co_pwritev(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkreplay_co_pwrite_zeroes(BlockDriverState *bs,
-    int64_t offset, int bytes, BdrvRequestFlags flags)
+    int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 74360b4853..d210e87a45 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -75,7 +75,7 @@ static int coroutine_fn cbw_co_pdiscard(BlockDriverState *bs,
 }
 
 static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs,
-        int64_t offset, int bytes, BdrvRequestFlags flags)
+        int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     int ret = cbw_do_copy_before_write(bs, offset, bytes, flags);
     if (ret < 0) {
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index b2ec36b6fc..f83dd83f14 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -193,7 +193,7 @@ static int coroutine_fn cor_co_pwritev_part(BlockDriverState *bs,
 
 
 static int coroutine_fn cor_co_pwrite_zeroes(BlockDriverState *bs,
-                                             int64_t offset, int bytes,
+                                             int64_t offset, int64_t bytes,
                                              BdrvRequestFlags flags)
 {
     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
diff --git a/block/file-posix.c b/block/file-posix.c
index ed71e8d2df..f375070f25 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2972,7 +2972,7 @@ raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
 }
 
 static int coroutine_fn
-raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
+raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
                      BdrvRequestFlags flags, bool blkdev)
 {
     BDRVRawState *s = bs->opaque;
@@ -3040,7 +3040,7 @@ raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
 
 static int coroutine_fn raw_co_pwrite_zeroes(
     BlockDriverState *bs, int64_t offset,
-    int bytes, BdrvRequestFlags flags)
+    int64_t bytes, BdrvRequestFlags flags)
 {
     return raw_do_pwrite_zeroes(bs, offset, bytes, flags, false);
 }
@@ -3605,7 +3605,7 @@ hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
 }
 
 static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs,
-    int64_t offset, int bytes, BdrvRequestFlags flags)
+    int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     int rc;
 
diff --git a/block/filter-compress.c b/block/filter-compress.c
index 505822a44f..fb85686b69 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -86,7 +86,7 @@ static int coroutine_fn compress_co_pwritev_part(BlockDriverState *bs,
 
 
 static int coroutine_fn compress_co_pwrite_zeroes(BlockDriverState *bs,
-                                                  int64_t offset, int bytes,
+                                                  int64_t offset, int64_t bytes,
                                                   BdrvRequestFlags flags)
 {
     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
diff --git a/block/gluster.c b/block/gluster.c
index d51938e447..4e3c9cd14f 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -1003,19 +1003,19 @@ static void qemu_gluster_reopen_abort(BDRVReopenState *state)
 #ifdef CONFIG_GLUSTERFS_ZEROFILL
 static coroutine_fn int qemu_gluster_co_pwrite_zeroes(BlockDriverState *bs,
                                                       int64_t offset,
-                                                      int size,
+                                                      int64_t bytes,
                                                       BdrvRequestFlags flags)
 {
     int ret;
     GlusterAIOCB acb;
     BDRVGlusterState *s = bs->opaque;
 
-    acb.size = size;
+    acb.size = bytes;
     acb.ret = 0;
     acb.coroutine = qemu_coroutine_self();
     acb.aio_context = bdrv_get_aio_context(bs);
 
-    ret = glfs_zerofill_async(s->fd, offset, size, gluster_finish_aiocb, &acb);
+    ret = glfs_zerofill_async(s->fd, offset, bytes, gluster_finish_aiocb, &acb);
     if (ret < 0) {
         return -errno;
     }
diff --git a/block/iscsi.c b/block/iscsi.c
index 01fdd1775f..74ff7e307e 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -427,14 +427,14 @@ static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
     return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
 }
 
-static bool is_byte_request_lun_aligned(int64_t offset, int count,
+static bool is_byte_request_lun_aligned(int64_t offset, int64_t bytes,
                                         IscsiLun *iscsilun)
 {
-    if (offset % iscsilun->block_size || count % iscsilun->block_size) {
+    if (offset % iscsilun->block_size || bytes % iscsilun->block_size) {
         error_report("iSCSI misaligned request: "
                      "iscsilun->block_size %u, offset %" PRIi64
-                     ", count %d",
-                     iscsilun->block_size, offset, count);
+                     ", bytes %" PRIi64,
+                     iscsilun->block_size, offset, bytes);
         return false;
     }
     return true;
@@ -1202,12 +1202,12 @@ out_unlock:
 
 static int
 coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
-                                    int bytes, BdrvRequestFlags flags)
+                                    int64_t bytes, BdrvRequestFlags flags)
 {
     IscsiLun *iscsilun = bs->opaque;
     struct IscsiTask iTask;
     uint64_t lba;
-    uint32_t nb_blocks;
+    uint64_t nb_blocks;
     bool use_16_for_ws = iscsilun->use_16_for_rw;
     int r = 0;
 
@@ -1247,11 +1247,21 @@ coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
     iscsi_co_init_iscsitask(iscsilun, &iTask);
 retry:
     if (use_16_for_ws) {
+        /*
+         * iscsi_writesame16_task num_blocks argument is uint32_t. We rely here
+         * on our max_pwrite_zeroes limit.
+         */
+        assert(nb_blocks <= UINT32_MAX);
         iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
                                             iscsilun->zeroblock, iscsilun->block_size,
                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
                                             0, 0, iscsi_co_generic_cb, &iTask);
     } else {
+        /*
+         * iscsi_writesame10_task num_blocks argument is uint16_t. We rely here
+         * on our max_pwrite_zeroes limit.
+         */
+        assert(nb_blocks <= UINT16_MAX);
         iTask.task = iscsi_writesame10_task(iscsilun->iscsi, iscsilun->lun, lba,
                                             iscsilun->zeroblock, iscsilun->block_size,
                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
@@ -2071,10 +2081,10 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
         bs->bl.pdiscard_alignment = iscsilun->block_size;
     }
 
-    if (iscsilun->bl.max_ws_len < 0xffffffff / block_size) {
-        bs->bl.max_pwrite_zeroes =
-            iscsilun->bl.max_ws_len * iscsilun->block_size;
-    }
+    bs->bl.max_pwrite_zeroes =
+        MIN_NON_ZERO(iscsilun->bl.max_ws_len * iscsilun->block_size,
+                     max_xfer_len * iscsilun->block_size);
+
     if (iscsilun->lbp.lbpws) {
         bs->bl.pwrite_zeroes_alignment =
             iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
diff --git a/block/mirror.c b/block/mirror.c
index c4c623ceed..fab75087b0 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1501,7 +1501,7 @@ static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs)
 }
 
 static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs,
-    int64_t offset, int bytes, BdrvRequestFlags flags)
+    int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_ZERO, offset, bytes, NULL,
                                     flags);
diff --git a/block/nbd.c b/block/nbd.c
index caee396525..c0c479abe9 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1407,15 +1407,17 @@ static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset,
 }
 
 static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
-                                       int bytes, BdrvRequestFlags flags)
+                                       int64_t bytes, BdrvRequestFlags flags)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
     NBDRequest request = {
         .type = NBD_CMD_WRITE_ZEROES,
         .from = offset,
-        .len = bytes,
+        .len = bytes,  /* .len is uint32_t actually */
     };
 
+    assert(bytes <= UINT32_MAX); /* rely on max_pwrite_zeroes */
+
     assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
     if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) {
         return -ENOTSUP;
diff --git a/block/nvme.c b/block/nvme.c
index c44db18939..2e0fd9e76a 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1296,19 +1296,29 @@ static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
 
 static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
                                               int64_t offset,
-                                              int bytes,
+                                              int64_t bytes,
                                               BdrvRequestFlags flags)
 {
     BDRVNVMeState *s = bs->opaque;
     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
     NVMeRequest *req;
-
-    uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
+    uint32_t cdw12;
 
     if (!s->supports_write_zeroes) {
         return -ENOTSUP;
     }
 
+    if (bytes == 0) {
+        return 0;
+    }
+
+    cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
+    /*
+     * We should not lose information. pwrite_zeroes_alignment and
+     * max_pwrite_zeroes guarantees it.
+     */
+    assert(((cdw12 + 1) << s->blkshift) == bytes);
+
     NvmeCmd cmd = {
         .opcode = NVME_CMD_WRITE_ZEROES,
         .nsid = cpu_to_le32(s->nsid),
@@ -1472,6 +1482,14 @@ static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
     bs->bl.opt_mem_alignment = s->page_size;
     bs->bl.request_alignment = s->page_size;
     bs->bl.max_transfer = s->max_transfer;
+
+    /*
+     * Look at nvme_co_pwrite_zeroes: after shift and decrement we should get
+     * at most 0xFFFF
+     */
+    bs->bl.max_pwrite_zeroes = 1ULL << (s->blkshift + 16);
+    bs->bl.pwrite_zeroes_alignment = MAX(bs->bl.request_alignment,
+                                         1UL << s->blkshift);
 }
 
 static void nvme_detach_aio_context(BlockDriverState *bs)
diff --git a/block/preallocate.c b/block/preallocate.c
index c19885af17..99e28d9f08 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -337,7 +337,7 @@ static bool coroutine_fn handle_write(BlockDriverState *bs, int64_t offset,
 }
 
 static int coroutine_fn preallocate_co_pwrite_zeroes(BlockDriverState *bs,
-        int64_t offset, int bytes, BdrvRequestFlags flags)
+        int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     bool want_merge_zero =
         !(flags & ~(BDRV_REQ_ZERO_WRITE | BDRV_REQ_NO_FALLBACK));
diff --git a/block/qcow2.c b/block/qcow2.c
index 520ae37a29..4b2e869495 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3941,7 +3941,7 @@ static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
 }
 
 static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
-    int64_t offset, int bytes, BdrvRequestFlags flags)
+    int64_t offset, int64_t bytes, BdrvRequestFlags flags)
 {
     int ret;
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/qed.c b/block/qed.c
index f45c640513..558d3646c4 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -582,6 +582,7 @@ static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp)
     BDRVQEDState *s = bs->opaque;
 
     bs->bl.pwrite_zeroes_alignment = s->header.cluster_size;
+    bs->bl.max_pwrite_zeroes = QEMU_ALIGN_DOWN(INT_MAX, s->header.cluster_size);
 }
 
 /* We have nothing to do for QED reopen, stubs just return
@@ -1397,7 +1398,7 @@ static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs,
 
 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
                                                   int64_t offset,
-                                                  int bytes,
+                                                  int64_t bytes,
                                                   BdrvRequestFlags flags)
 {
     BDRVQEDState *s = bs->opaque;
@@ -1408,6 +1409,12 @@ static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
      */
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
 
+    /*
+     * QED is not prepared for 63bit write-zero requests, so rely on
+     * max_pwrite_zeroes.
+     */
+    assert(bytes <= INT_MAX);
+
     /* Fall back if the request is not aligned */
     if (qed_offset_into_cluster(s, offset) ||
         qed_offset_into_cluster(s, bytes)) {
diff --git a/block/quorum.c b/block/quorum.c
index f4b76ea010..c28dda7baa 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -746,7 +746,7 @@ static int quorum_co_pwritev(BlockDriverState *bs, int64_t offset,
 }
 
 static int quorum_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
-                                   int bytes, BdrvRequestFlags flags)
+                                   int64_t bytes, BdrvRequestFlags flags)
 
 {
     return quorum_co_pwritev(bs, offset, bytes, NULL,
diff --git a/block/raw-format.c b/block/raw-format.c
index 345137813e..a2485926b8 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -289,7 +289,7 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
 }
 
 static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
-                                             int64_t offset, int bytes,
+                                             int64_t offset, int64_t bytes,
                                              BdrvRequestFlags flags)
 {
     int ret;
diff --git a/block/rbd.c b/block/rbd.c
index efc0835ee7..053eb8e48f 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1205,9 +1205,9 @@ static int coroutine_fn qemu_rbd_co_pdiscard(BlockDriverState *bs,
 #ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
 static int
 coroutine_fn qemu_rbd_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
-                                      int count, BdrvRequestFlags flags)
+                                       int64_t bytes, BdrvRequestFlags flags)
 {
-    return qemu_rbd_start_co(bs, offset, count, NULL, flags,
+    return qemu_rbd_start_co(bs, offset, bytes, NULL, flags,
                              RBD_AIO_WRITE_ZEROES);
 }
 #endif
diff --git a/block/throttle.c b/block/throttle.c
index 1330e844c3..c13fe9067f 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -135,7 +135,7 @@ static int coroutine_fn throttle_co_pwritev(BlockDriverState *bs,
 }
 
 static int coroutine_fn throttle_co_pwrite_zeroes(BlockDriverState *bs,
-                                                  int64_t offset, int bytes,
+                                                  int64_t offset, int64_t bytes,
                                                   BdrvRequestFlags flags)
 {
     ThrottleGroupMember *tgm = bs->opaque;
diff --git a/block/trace-events b/block/trace-events
index 983dd54830..d8a08563f1 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -80,8 +80,8 @@ qcow2_writev_done_req(void *co, int ret) "co %p ret %d"
 qcow2_writev_start_part(void *co) "co %p"
 qcow2_writev_done_part(void *co, int cur_bytes) "co %p cur_bytes %d"
 qcow2_writev_data(void *co, uint64_t offset) "co %p offset 0x%" PRIx64
-qcow2_pwrite_zeroes_start_req(void *co, int64_t offset, int count) "co %p offset 0x%" PRIx64 " count %d"
-qcow2_pwrite_zeroes(void *co, int64_t offset, int count) "co %p offset 0x%" PRIx64 " count %d"
+qcow2_pwrite_zeroes_start_req(void *co, int64_t offset, int64_t bytes) "co %p offset 0x%" PRIx64 " bytes %" PRId64
+qcow2_pwrite_zeroes(void *co, int64_t offset, int64_t bytes) "co %p offset 0x%" PRIx64 " bytes %" PRId64
 qcow2_skip_cow(void *co, uint64_t offset, int nb_clusters) "co %p offset 0x%" PRIx64 " nb_clusters %d"
 
 # qcow2-cluster.c
diff --git a/block/vmdk.c b/block/vmdk.c
index 8d49e54bdd..fb4cc9da90 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2109,7 +2109,7 @@ vmdk_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes,
 
 static int coroutine_fn vmdk_co_pwrite_zeroes(BlockDriverState *bs,
                                               int64_t offset,
-                                              int bytes,
+                                              int64_t bytes,
                                               BdrvRequestFlags flags)
 {
     int ret;
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 24958acd33..d518703e3e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -301,7 +301,7 @@ struct BlockDriver {
      * will be called instead.
      */
     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
-        int64_t offset, int bytes, BdrvRequestFlags flags);
+        int64_t offset, int64_t bytes, BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
         int64_t offset, int bytes);
 

From 2aaa3f9b33afca9733700b94d764e45ac009b8e5 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:04 +0300
Subject: [PATCH 09/19] block/io: allow 64bit write-zeroes requests

Now that all drivers are updated by previous commit, we can drop two
last limiters on write-zeroes path: INT_MAX in
bdrv_co_do_pwrite_zeroes() and bdrv_check_request32() in
bdrv_co_pwritev_part().

Now everything is prepared for implementing incredibly cool and fast
big-write-zeroes in NBD and qcow2. And any other driver which wants it
of course.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-9-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index 0090224603..e40462742e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1869,7 +1869,8 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int head = 0;
     int tail = 0;
 
-    int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
+    int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes,
+                                            INT64_MAX);
     int alignment = MAX(bs->bl.pwrite_zeroes_alignment,
                         bs->bl.request_alignment);
     int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER);
@@ -2248,7 +2249,11 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
         return -ENOMEDIUM;
     }
 
-    ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset);
+    if (flags & BDRV_REQ_ZERO_WRITE) {
+        ret = bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, NULL);
+    } else {
+        ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset);
+    }
     if (ret < 0) {
         return ret;
     }

From 39af49c0d7e0a2a285f1bcbd3db0db88f15b1d8c Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:05 +0300
Subject: [PATCH 10/19] block: make BlockLimits::max_pdiscard 64bit

We are going to support 64 bit discard requests. Now update the
limit variable. It's absolutely safe. The variable is set in some
drivers, and used in bdrv_co_pdiscard().

Update also max_pdiscard variable in bdrv_co_pdiscard(), so that
bdrv_co_pdiscard() is now prepared for 64bit requests. The remaining
logic including num, offset and bytes variables is already
supporting 64bit requests.

So the only thing that prevents 64 bit requests is limiting
max_pdiscard variable to INT_MAX in bdrv_co_pdiscard().
We'll drop this limitation after updating all block drivers.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-10-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c                |  3 ++-
 include/block/block_int.h | 11 ++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/block/io.c b/block/io.c
index e40462742e..3846e2ed96 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3056,7 +3056,8 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset,
                                   int64_t bytes)
 {
     BdrvTrackedRequest req;
-    int max_pdiscard, ret;
+    int ret;
+    int64_t max_pdiscard;
     int head, tail, align;
     BlockDriverState *bs = child->bs;
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index d518703e3e..9b4e0748bc 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -674,11 +674,12 @@ typedef struct BlockLimits {
      * otherwise. */
     uint32_t request_alignment;
 
-    /* Maximum number of bytes that can be discarded at once (since it
-     * is signed, it must be < 2G, if set). Must be multiple of
-     * pdiscard_alignment, but need not be power of 2. May be 0 if no
-     * inherent 32-bit limit */
-    int32_t max_pdiscard;
+    /*
+     * Maximum number of bytes that can be discarded at once. Must be multiple
+     * of pdiscard_alignment, but need not be power of 2. May be 0 if no
+     * inherent 64-bit limit.
+     */
+    int64_t max_pdiscard;
 
     /* Optimal alignment for discard requests in bytes. A power of 2
      * is best but not mandatory.  Must be a multiple of

From 0c8022876f2183f93e23a7314862140c94ee62e7 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:06 +0300
Subject: [PATCH 11/19] block: use int64_t instead of int in driver discard
 handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver discard handlers bytes parameter to int64_t.

The only caller of all updated function is bdrv_co_pdiscard in
block/io.c. It is already prepared to work with 64bit requests, but
pass at most max(bs->bl.max_pdiscard, INT_MAX) to the driver.

Let's look at all updated functions:

blkdebug: all calculations are still OK, thanks to
  bdrv_check_qiov_request().
  both rule_check and bdrv_co_pdiscard are 64bit

blklogwrites: pass to blk_loc_writes_co_log which is 64bit

blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pdiscard, OK

copy-before-write: pass to bdrv_co_pdiscard which is 64bit and to
  cbw_do_copy_before_write which is 64bit

file-posix: one handler calls raw_account_discard() is 64bit and both
  handlers calls raw_do_pdiscard(). Update raw_do_pdiscard, which pass
  to RawPosixAIOData::aio_nbytes, which is 64bit (and calls
  raw_account_discard())

gluster: somehow, third argument of glfs_discard_async is size_t.
  Let's set max_pdiscard accordingly.

iscsi: iscsi_allocmap_set_invalid is 64bit,
  !is_byte_request_lun_aligned is 64bit.
  list.num is uint32_t. Let's clarify max_pdiscard and
  pdiscard_alignment.

mirror_top: pass to bdrv_mirror_top_do_write() which is
  64bit

nbd: protocol limitation. max_pdiscard is alredy set strict enough,
  keep it as is for now.

nvme: buf.nlb is uint32_t and we do shift. So, add corresponding limits
  to nvme_refresh_limits().

preallocate: pass to bdrv_co_pdiscard() which is 64bit.

rbd: pass to qemu_rbd_start_co() which is 64bit.

qcow2: calculations are still OK, thanks to bdrv_check_qiov_request(),
  qcow2_cluster_discard() is 64bit.

raw-format: raw_adjust_offset() is 64bit, bdrv_co_pdiscard too.

throttle: pass to bdrv_co_pdiscard() which is 64bit and to
  throttle_group_co_io_limits_intercept() which is 64bit as well.

test-block-iothread: bytes argument is unused

Great! Now all drivers are prepared to handle 64bit discard requests,
or else have explicit max_pdiscard limits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-11-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/blkdebug.c                 |  2 +-
 block/blklogwrites.c             |  4 ++--
 block/blkreplay.c                |  2 +-
 block/copy-before-write.c        |  2 +-
 block/copy-on-read.c             |  2 +-
 block/file-posix.c               |  7 ++++---
 block/filter-compress.c          |  2 +-
 block/gluster.c                  |  7 +++++--
 block/iscsi.c                    | 16 +++++++++++-----
 block/mirror.c                   |  2 +-
 block/nbd.c                      |  6 ++++--
 block/nvme.c                     | 14 +++++++++++++-
 block/preallocate.c              |  2 +-
 block/qcow2.c                    |  2 +-
 block/raw-format.c               |  2 +-
 block/rbd.c                      |  4 ++--
 block/throttle.c                 |  2 +-
 block/trace-events               |  4 ++--
 include/block/block_int.h        |  2 +-
 tests/unit/test-block-iothread.c |  2 +-
 20 files changed, 55 insertions(+), 31 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 742b4a3834..bbf2948703 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -717,7 +717,7 @@ static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     uint32_t align = bs->bl.pdiscard_alignment;
     int err;
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index d7ae64c22d..f7a251e91f 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -484,9 +484,9 @@ static int coroutine_fn blk_log_writes_co_flush_to_disk(BlockDriverState *bs)
 }
 
 static int coroutine_fn
-blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
+blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
-    return blk_log_writes_co_log(bs, offset, count, NULL, 0,
+    return blk_log_writes_co_log(bs, offset, bytes, NULL, 0,
                                  blk_log_writes_co_do_file_pdiscard,
                                  LOG_DISCARD_FLAG, false);
 }
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 89d74a3cca..dcbe780ddb 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -105,7 +105,7 @@ static int coroutine_fn blkreplay_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkreplay_co_pdiscard(BlockDriverState *bs,
-                                              int64_t offset, int bytes)
+                                              int64_t offset, int64_t bytes)
 {
     uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_pdiscard(bs->file, offset, bytes);
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index d210e87a45..c30a5ff8de 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -64,7 +64,7 @@ static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
 }
 
 static int coroutine_fn cbw_co_pdiscard(BlockDriverState *bs,
-                                        int64_t offset, int bytes)
+                                        int64_t offset, int64_t bytes)
 {
     int ret = cbw_do_copy_before_write(bs, offset, bytes, 0);
     if (ret < 0) {
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index f83dd83f14..1fc7fb3333 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -201,7 +201,7 @@ static int coroutine_fn cor_co_pwrite_zeroes(BlockDriverState *bs,
 
 
 static int coroutine_fn cor_co_pdiscard(BlockDriverState *bs,
-                                        int64_t offset, int bytes)
+                                        int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/file-posix.c b/block/file-posix.c
index f375070f25..c62e42743d 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2942,7 +2942,8 @@ static void raw_account_discard(BDRVRawState *s, uint64_t nbytes, int ret)
 }
 
 static coroutine_fn int
-raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
+raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                bool blkdev)
 {
     BDRVRawState *s = bs->opaque;
     RawPosixAIOData acb;
@@ -2966,7 +2967,7 @@ raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
 }
 
 static coroutine_fn int
-raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     return raw_do_pdiscard(bs, offset, bytes, false);
 }
@@ -3591,7 +3592,7 @@ hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 #endif /* linux */
 
 static coroutine_fn int
-hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     BDRVRawState *s = bs->opaque;
     int ret;
diff --git a/block/filter-compress.c b/block/filter-compress.c
index fb85686b69..d5be538619 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -94,7 +94,7 @@ static int coroutine_fn compress_co_pwrite_zeroes(BlockDriverState *bs,
 
 
 static int coroutine_fn compress_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/gluster.c b/block/gluster.c
index 4e3c9cd14f..398976bc66 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -891,6 +891,7 @@ out:
 static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp)
 {
     bs->bl.max_transfer = GLUSTER_MAX_TRANSFER;
+    bs->bl.max_pdiscard = SIZE_MAX;
 }
 
 static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
@@ -1297,18 +1298,20 @@ error:
 
 #ifdef CONFIG_GLUSTERFS_DISCARD
 static coroutine_fn int qemu_gluster_co_pdiscard(BlockDriverState *bs,
-                                                 int64_t offset, int size)
+                                                 int64_t offset, int64_t bytes)
 {
     int ret;
     GlusterAIOCB acb;
     BDRVGlusterState *s = bs->opaque;
 
+    assert(bytes <= SIZE_MAX); /* rely on max_pdiscard */
+
     acb.size = 0;
     acb.ret = 0;
     acb.coroutine = qemu_coroutine_self();
     acb.aio_context = bdrv_get_aio_context(bs);
 
-    ret = glfs_discard_async(s->fd, offset, size, gluster_finish_aiocb, &acb);
+    ret = glfs_discard_async(s->fd, offset, bytes, gluster_finish_aiocb, &acb);
     if (ret < 0) {
         return -errno;
     }
diff --git a/block/iscsi.c b/block/iscsi.c
index 74ff7e307e..57aa07a40d 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1138,7 +1138,8 @@ iscsi_getlength(BlockDriverState *bs)
 }
 
 static int
-coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset,
+                               int64_t bytes)
 {
     IscsiLun *iscsilun = bs->opaque;
     struct IscsiTask iTask;
@@ -1154,6 +1155,12 @@ coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
         return 0;
     }
 
+    /*
+     * We don't want to overflow list.num which is uint32_t.
+     * We rely on our max_pdiscard.
+     */
+    assert(bytes / iscsilun->block_size <= UINT32_MAX);
+
     list.lba = offset / iscsilun->block_size;
     list.num = bytes / iscsilun->block_size;
 
@@ -2071,10 +2078,9 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
     }
 
     if (iscsilun->lbp.lbpu) {
-        if (iscsilun->bl.max_unmap < 0xffffffff / block_size) {
-            bs->bl.max_pdiscard =
-                iscsilun->bl.max_unmap * iscsilun->block_size;
-        }
+        bs->bl.max_pdiscard =
+            MIN_NON_ZERO(iscsilun->bl.max_unmap * iscsilun->block_size,
+                         (uint64_t)UINT32_MAX * iscsilun->block_size);
         bs->bl.pdiscard_alignment =
             iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
     } else {
diff --git a/block/mirror.c b/block/mirror.c
index fab75087b0..c962e8b471 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1508,7 +1508,7 @@ static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs,
-    int64_t offset, int bytes)
+    int64_t offset, int64_t bytes)
 {
     return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, offset, bytes,
                                     NULL, 0);
diff --git a/block/nbd.c b/block/nbd.c
index c0c479abe9..a66b2c282d 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1457,15 +1457,17 @@ static int nbd_client_co_flush(BlockDriverState *bs)
 }
 
 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset,
-                                  int bytes)
+                                  int64_t bytes)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
     NBDRequest request = {
         .type = NBD_CMD_TRIM,
         .from = offset,
-        .len = bytes,
+        .len = bytes, /* len is uint32_t */
     };
 
+    assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */
+
     assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
     if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) {
         return 0;
diff --git a/block/nvme.c b/block/nvme.c
index 2e0fd9e76a..1cc7b62bb4 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1360,7 +1360,7 @@ static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
 
 static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
                                          int64_t offset,
-                                         int bytes)
+                                         int64_t bytes)
 {
     BDRVNVMeState *s = bs->opaque;
     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
@@ -1387,6 +1387,14 @@ static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
 
     assert(s->queue_count > 1);
 
+    /*
+     * Filling the @buf requires @offset and @bytes to satisfy restrictions
+     * defined in nvme_refresh_limits().
+     */
+    assert(QEMU_IS_ALIGNED(bytes, 1UL << s->blkshift));
+    assert(QEMU_IS_ALIGNED(offset, 1UL << s->blkshift));
+    assert((bytes >> s->blkshift) <= UINT32_MAX);
+
     buf = qemu_try_memalign(s->page_size, s->page_size);
     if (!buf) {
         return -ENOMEM;
@@ -1490,6 +1498,10 @@ static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
     bs->bl.max_pwrite_zeroes = 1ULL << (s->blkshift + 16);
     bs->bl.pwrite_zeroes_alignment = MAX(bs->bl.request_alignment,
                                          1UL << s->blkshift);
+
+    bs->bl.max_pdiscard = (uint64_t)UINT32_MAX << s->blkshift;
+    bs->bl.pdiscard_alignment = MAX(bs->bl.request_alignment,
+                                    1UL << s->blkshift);
 }
 
 static void nvme_detach_aio_context(BlockDriverState *bs)
diff --git a/block/preallocate.c b/block/preallocate.c
index 99e28d9f08..1d4233f730 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -235,7 +235,7 @@ static coroutine_fn int preallocate_co_preadv_part(
 }
 
 static int coroutine_fn preallocate_co_pdiscard(BlockDriverState *bs,
-                                               int64_t offset, int bytes)
+                                               int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index 4b2e869495..d509016756 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3996,7 +3996,7 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
-                                          int64_t offset, int bytes)
+                                          int64_t offset, int64_t bytes)
 {
     int ret;
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/raw-format.c b/block/raw-format.c
index a2485926b8..bda757fd19 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -302,7 +302,7 @@ static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
-                                        int64_t offset, int bytes)
+                                        int64_t offset, int64_t bytes)
 {
     int ret;
 
diff --git a/block/rbd.c b/block/rbd.c
index 053eb8e48f..701fbf2b0c 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1197,9 +1197,9 @@ static int coroutine_fn qemu_rbd_co_flush(BlockDriverState *bs)
 }
 
 static int coroutine_fn qemu_rbd_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int count)
+                                             int64_t offset, int64_t bytes)
 {
-    return qemu_rbd_start_co(bs, offset, count, NULL, 0, RBD_AIO_DISCARD);
+    return qemu_rbd_start_co(bs, offset, bytes, NULL, 0, RBD_AIO_DISCARD);
 }
 
 #ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
diff --git a/block/throttle.c b/block/throttle.c
index c13fe9067f..6e8d52fa24 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -145,7 +145,7 @@ static int coroutine_fn throttle_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     ThrottleGroupMember *tgm = bs->opaque;
     throttle_group_co_io_limits_intercept(tgm, bytes, true);
diff --git a/block/trace-events b/block/trace-events
index d8a08563f1..f2d0a9b62a 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -152,8 +152,8 @@ nvme_write_zeroes(void *s, uint64_t offset, uint64_t bytes, int flags) "s %p off
 nvme_qiov_unaligned(const void *qiov, int n, void *base, size_t size, int align) "qiov %p n %d base %p size 0x%zx align 0x%x"
 nvme_prw_buffered(void *s, uint64_t offset, uint64_t bytes, int niov, int is_write) "s %p offset 0x%"PRIx64" bytes %"PRId64" niov %d is_write %d"
 nvme_rw_done(void *s, int is_write, uint64_t offset, uint64_t bytes, int ret) "s %p is_write %d offset 0x%"PRIx64" bytes %"PRId64" ret %d"
-nvme_dsm(void *s, uint64_t offset, uint64_t bytes) "s %p offset 0x%"PRIx64" bytes %"PRId64""
-nvme_dsm_done(void *s, uint64_t offset, uint64_t bytes, int ret) "s %p offset 0x%"PRIx64" bytes %"PRId64" ret %d"
+nvme_dsm(void *s, int64_t offset, int64_t bytes) "s %p offset 0x%"PRIx64" bytes %"PRId64""
+nvme_dsm_done(void *s, int64_t offset, int64_t bytes, int ret) "s %p offset 0x%"PRIx64" bytes %"PRId64" ret %d"
 nvme_dma_map_flush(void *s) "s %p"
 nvme_free_req_queue_wait(void *s, unsigned q_index) "s %p q #%u"
 nvme_create_queue_pair(unsigned q_index, void *q, size_t size, void *aio_context, int fd) "index %u q %p size %zu aioctx %p fd %d"
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 9b4e0748bc..ffe86068d4 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -303,7 +303,7 @@ struct BlockDriver {
     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
         int64_t offset, int64_t bytes, BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
-        int64_t offset, int bytes);
+        int64_t offset, int64_t bytes);
 
     /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
      * and invoke bdrv_co_copy_range_from(child, ...), or invoke
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index c86954c7ba..aea660aeed 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -48,7 +48,7 @@ static int coroutine_fn bdrv_test_co_pwritev(BlockDriverState *bs,
 }
 
 static int coroutine_fn bdrv_test_co_pdiscard(BlockDriverState *bs,
-                                              int64_t offset, int bytes)
+                                              int64_t offset, int64_t bytes)
 {
     return 0;
 }

From 6a8f3dbb1912141c9806c22db394a9ac8fe8366c Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Fri, 3 Sep 2021 13:28:07 +0300
Subject: [PATCH 12/19] block/io: allow 64bit discard requests

Now that all drivers are updated by the previous commit, we can drop
the last limiter on pdiscard path: INT_MAX in bdrv_co_pdiscard().

Now everything is prepared for implementing incredibly cool and fast
big-discard requests in NBD and qcow2. And any other driver which wants
it of course.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-12-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/io.c b/block/io.c
index 3846e2ed96..18d345a87a 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3104,7 +3104,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset,
         goto out;
     }
 
-    max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT_MAX),
+    max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT64_MAX),
                                    align);
     assert(max_pdiscard >= bs->bl.request_alignment);
 

From da24597dd37bc31b4d2328e5542fa3b5676a3fe0 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Tue, 7 Sep 2021 12:35:05 -0500
Subject: [PATCH 13/19] nbd/server: Allow LIST_META_CONTEXT without
 STRUCTURED_REPLY

The NBD protocol just relaxed the requirements on
NBD_OPT_LIST_META_CONTEXT:

https://github.com/NetworkBlockDevice/nbd/commit/13a4e33a87

Since listing is not stateful (unlike SET_META_CONTEXT), we don't care
if a client asks for meta contexts without first requesting structured
replies.  Well-behaved clients will still ask for structured reply
first (if for no other reason than for back-compat to older servers),
but that's no reason to avoid this change.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210907173505.1499709-1-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 nbd/server.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nbd/server.c b/nbd/server.c
index 3927f7789d..6d03e8a4b4 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -980,7 +980,7 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
     size_t i;
     size_t count = 0;
 
-    if (!client->structured_reply) {
+    if (client->opt == NBD_OPT_SET_META_CONTEXT && !client->structured_reply) {
         return nbd_opt_invalid(client, errp,
                                "request option '%s' when structured reply "
                                "is not negotiated",

From f7ca4aadca865898ef9c52d75f142a9db622c712 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Mon, 6 Sep 2021 22:06:46 +0300
Subject: [PATCH 14/19] nbd/client-connection: nbd_co_establish_connection():
 fix non set errp

When we don't have a connection and blocking is false, we return NULL
but don't set errp. That's wrong.

We have two paths for calling nbd_co_establish_connection():

1. nbd_open() -> nbd_do_establish_connection() -> ...
  but that will never set blocking=false

2. nbd_reconnect_attempt() -> nbd_co_do_establish_connection() -> ...
  but that uses errp=NULL

So, we are safe with our wrong errp policy in
nbd_co_establish_connection(). Still let's fix it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210906190654.183421-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 nbd/client-connection.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/nbd/client-connection.c b/nbd/client-connection.c
index 7123b1e189..695f855754 100644
--- a/nbd/client-connection.c
+++ b/nbd/client-connection.c
@@ -318,6 +318,7 @@ nbd_co_establish_connection(NBDClientConnection *conn, NBDExportInfo *info,
         }
 
         if (!blocking) {
+            error_setg(errp, "No connection at the moment");
             return NULL;
         }
 

From cb116da7d722f1c5fbb32c818817aef0f576772d Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Thu, 2 Sep 2021 13:38:01 +0300
Subject: [PATCH 15/19] block/nbd: nbd_channel_error() shutdown channel
 unconditionally

Don't rely on connection being totally broken in case of -EIO. Safer
and more correct is to just shut down the channel anyway, since we
change the state and plan on reconnecting.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210902103805.25686-2-vsementsov@virtuozzo.com>
[eblake: grammar tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/nbd.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index a66b2c282d..de59e76378 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -129,15 +129,16 @@ static bool nbd_client_connected(BDRVNBDState *s)
 
 static void nbd_channel_error(BDRVNBDState *s, int ret)
 {
+    if (nbd_client_connected(s)) {
+        qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+    }
+
     if (ret == -EIO) {
         if (nbd_client_connected(s)) {
             s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT :
                                             NBD_CLIENT_CONNECTING_NOWAIT;
         }
     } else {
-        if (nbd_client_connected(s)) {
-            qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
-        }
         s->state = NBD_CLIENT_QUIT;
     }
 }

From 3bc0bd1f4292758417738739d1594a55f283498b Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Thu, 2 Sep 2021 13:38:02 +0300
Subject: [PATCH 16/19] block/nbd: move nbd_recv_coroutines_wake_all() up

We are going to use it in nbd_channel_error(), so move it up. Note,
that we are going also refactor and rename
nbd_recv_coroutines_wake_all() in future anyway, so keeping it where it
is and making forward declaration doesn't make real sense.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210902103805.25686-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/nbd.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index de59e76378..2842e6263f 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -127,6 +127,20 @@ static bool nbd_client_connected(BDRVNBDState *s)
     return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED;
 }
 
+static void nbd_recv_coroutines_wake_all(BDRVNBDState *s)
+{
+    int i;
+
+    for (i = 0; i < MAX_NBD_REQUESTS; i++) {
+        NBDClientRequest *req = &s->requests[i];
+
+        if (req->coroutine && req->receiving) {
+            req->receiving = false;
+            aio_co_wake(req->coroutine);
+        }
+    }
+}
+
 static void nbd_channel_error(BDRVNBDState *s, int ret)
 {
     if (nbd_client_connected(s)) {
@@ -143,20 +157,6 @@ static void nbd_channel_error(BDRVNBDState *s, int ret)
     }
 }
 
-static void nbd_recv_coroutines_wake_all(BDRVNBDState *s)
-{
-    int i;
-
-    for (i = 0; i < MAX_NBD_REQUESTS; i++) {
-        NBDClientRequest *req = &s->requests[i];
-
-        if (req->coroutine && req->receiving) {
-            req->receiving = false;
-            aio_co_wake(req->coroutine);
-        }
-    }
-}
-
 static void reconnect_delay_timer_del(BDRVNBDState *s)
 {
     if (s->reconnect_delay_timer) {

From 04a953b232751f4074fd3365c82c82e11cc2d241 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Thu, 2 Sep 2021 13:38:03 +0300
Subject: [PATCH 17/19] block/nbd: refactor nbd_recv_coroutines_wake_all()

Split out nbd_recv_coroutine_wake_one(), as it will be used
separately.
Rename the function and add a possibility to wake only first found
sleeping coroutine.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210902103805.25686-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/nbd.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index 2842e6263f..709c2499e3 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -127,16 +127,24 @@ static bool nbd_client_connected(BDRVNBDState *s)
     return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED;
 }
 
-static void nbd_recv_coroutines_wake_all(BDRVNBDState *s)
+static bool nbd_recv_coroutine_wake_one(NBDClientRequest *req)
+{
+    if (req->receiving) {
+        req->receiving = false;
+        aio_co_wake(req->coroutine);
+        return true;
+    }
+
+    return false;
+}
+
+static void nbd_recv_coroutines_wake(BDRVNBDState *s, bool all)
 {
     int i;
 
     for (i = 0; i < MAX_NBD_REQUESTS; i++) {
-        NBDClientRequest *req = &s->requests[i];
-
-        if (req->coroutine && req->receiving) {
-            req->receiving = false;
-            aio_co_wake(req->coroutine);
+        if (nbd_recv_coroutine_wake_one(&s->requests[i]) && !all) {
+            return;
         }
     }
 }
@@ -415,7 +423,7 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
 
     while (s->in_flight > 0) {
         qemu_co_mutex_unlock(&s->send_mutex);
-        nbd_recv_coroutines_wake_all(s);
+        nbd_recv_coroutines_wake(s, true);
         s->wait_in_flight = true;
         qemu_coroutine_yield();
         s->wait_in_flight = false;
@@ -558,7 +566,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque)
     }
 
     qemu_co_queue_restart_all(&s->free_sema);
-    nbd_recv_coroutines_wake_all(s);
+    nbd_recv_coroutines_wake(s, true);
     bdrv_dec_in_flight(s->bs);
 
     s->connection_co = NULL;
@@ -1035,7 +1043,7 @@ static coroutine_fn int nbd_co_receive_one_chunk(
     if (s->connection_co && !s->wait_in_flight) {
         /*
          * We must check s->wait_in_flight, because we may entered by
-         * nbd_recv_coroutines_wake_all(), in this case we should not
+         * nbd_recv_coroutines_wake(), in this case we should not
          * wake connection_co here, it will woken by last request.
          */
         aio_co_wake(s->connection_co);

From 4ddb5d2fde6f22b2cf65f314107e890a7ca14fcf Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Thu, 2 Sep 2021 13:38:04 +0300
Subject: [PATCH 18/19] block/nbd: drop connection_co

OK, that's a big rewrite of the logic.

Pre-patch we have an always running coroutine - connection_co. It does
reply receiving and reconnecting. And it leads to a lot of difficult
and unobvious code around drained sections and context switch. We also
abuse bs->in_flight counter which is increased for connection_co and
temporary decreased in points where we want to allow drained section to
begin. One of these place is in another file: in nbd_read_eof() in
nbd/client.c.

We also cancel reconnect and requests waiting for reconnect on drained
begin which is not correct. And this patch fixes that.

Let's finally drop this always running coroutine and go another way:
do both reconnect and receiving in request coroutines.

The detailed list of changes below (in the sequence of diff hunks).

1. receiving coroutines are woken directly from nbd_channel_error, when
   we change s->state

2. nbd_co_establish_connection_cancel(): we don't have drain_begin now,
   and in nbd_teardown_connection() all requests should already be
   finished (and reconnect is done from request). So
   nbd_co_establish_connection_cancel() is called from
   nbd_cancel_in_flight() (to cancel the request that is doing
   nbd_co_establish_connection()) and from reconnect_delay_timer_cb()
   (previously we didn't need it, as reconnect delay only should cancel
   active requests not the reconnection itself). But now reconnection
   itself is done in the separate thread (we now call
   nbd_client_connection_enable_retry() in nbd_open()), and we need to
   cancel the requests that wait in nbd_co_establish_connection()
   now).

2A. We do receive headers in request coroutine. But we also should
   dispatch replies for other pending requests. So,
   nbd_connection_entry() is turned into nbd_receive_replies(), which
   does reply dispatching while it receives other request headers, and
   returns when it receives the requested header.

3. All old staff around drained sections and context switch is dropped.
   In details:
   - we don't need to move connection_co to new aio context, as we
     don't have connection_co anymore
   - we don't have a fake "request" of connection_co (extra increasing
     in_flight), so don't care with it in drain_begin/end
   - we don't stop reconnection during drained section anymore. This
     means that drain_begin may wait for a long time (up to
     reconnect_delay). But that's an improvement and more correct
     behavior see below[*]

4. In nbd_teardown_connection() we don't have to wait for
   connection_co, as it is dropped. And cleanup for s->ioc and nbd_yank
   is moved here from removed connection_co.

5. In nbd_co_do_establish_connection() we now should handle
   NBD_CLIENT_CONNECTING_NOWAIT: if new request comes when we are in
   NBD_CLIENT_CONNECTING_NOWAIT, it still should call
   nbd_co_establish_connection() (who knows, maybe the connection was
   already established by another thread in the background). But we
   shouldn't wait: if nbd_co_establish_connection() can't return new
   channel immediately the request should fail (we are in
   NBD_CLIENT_CONNECTING_NOWAIT state).

6. nbd_reconnect_attempt() is simplified: it's now easier to wait for
   other requests in the caller, so here we just assert that fact.
   Also delay time is now initialized here: we can easily detect first
   attempt and start a timer.

7. nbd_co_reconnect_loop() is dropped, we don't need it. Reconnect
   retries are fully handle by thread (nbd/client-connection.c), delay
   timer we initialize in nbd_reconnect_attempt(), we don't have to
   bother with s->drained and friends. nbd_reconnect_attempt() now
   called from nbd_co_send_request().

8. nbd_connection_entry is dropped: reconnect is now handled by
   nbd_co_send_request(), receiving reply is now handled by
   nbd_receive_replies(): all handled from request coroutines.

9. So, welcome new nbd_receive_replies() called from request coroutine,
   that receives reply header instead of nbd_connection_entry().
   Like with sending requests, only one coroutine may receive in a
   moment. So we introduce receive_mutex, which is locked around
   nbd_receive_reply(). It also protects some related fields. Still,
   full audit of thread-safety in nbd driver is a separate task.
   New function waits for a reply with specified handle being received
   and works rather simple:

   Under mutex:
     - if current handle is 0, do receive by hand. If another handle
       received - switch to other request coroutine, release mutex and
       yield. Otherwise return success
     - if current handle == requested handle, we are done
     - otherwise, release mutex and yield

10: in nbd_co_send_request() we now do nbd_reconnect_attempt() if
    needed. Also waiting in free_sema queue we now wait for one of two
    conditions:
    - connectED, in_flight < MAX_NBD_REQUESTS (so we can start new one)
    - connectING, in_flight == 0, so we can call
      nbd_reconnect_attempt()
    And this logic is protected by s->send_mutex

    Also, on failure we don't have to care of removed s->connection_co

11. nbd_co_do_receive_one_chunk(): now instead of yield() and wait for
    s->connection_co we just call new nbd_receive_replies().

12. nbd_co_receive_one_chunk(): place where s->reply.handle becomes 0,
    which means that handling of the whole reply is finished. Here we
    need to wake one of coroutines sleeping in nbd_receive_replies().
    If none are sleeping - do nothing. That's another behavior change: we
    don't have endless recv() in the idle time. It may be considered as
    a drawback. If so, it may be fixed later.

13. nbd_reply_chunk_iter_receive(): don't care about removed
    connection_co, just ping in_flight waiters.

14. Don't create connection_co, enable retry in the connection thread
    (we don't have own reconnect loop anymore)

15. We now need to add a nbd_co_establish_connection_cancel() call in
    nbd_cancel_in_flight(), to cancel the request that is doing a
    connection attempt.

[*], ok, now we don't cancel reconnect on drain begin. That's correct:
    reconnect feature leads to possibility of long-running requests (up
    to reconnect delay). Still, drain begin is not a reason to kill
    long requests. We should wait for them.

    This also means, that we can again reproduce a dead-lock, described
    in 8c517de24a8a1dcbeb54e7e12b5b0fda42a90ace.
    Why we are OK with it:
    1. Now this is not absolutely-dead dead-lock: the vm is unfrozen
       after reconnect delay. Actually 8c517de24a8a1dc fixed a bug in
       NBD logic, that was not described in 8c517de24a8a1dc and led to
       forever dead-lock. The problem was that nobody woke the free_sema
       queue, but drain_begin can't finish until there is a request in
       free_sema queue. Now we have a reconnect delay timer that works
       well.
    2. It's not a problem of the NBD driver, but of the ide code,
       because it does drain_begin under the global mutex; the problem
       doesn't reproduce when using scsi instead of ide.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210902103805.25686-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar and comment tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/nbd.c  | 381 ++++++++++++++-------------------------------------
 nbd/client.c |   2 -
 2 files changed, 103 insertions(+), 280 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index 709c2499e3..8ff6daf43d 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -57,7 +57,7 @@
 typedef struct {
     Coroutine *coroutine;
     uint64_t offset;        /* original offset of the request */
-    bool receiving;         /* waiting for connection_co? */
+    bool receiving;         /* sleeping in the yield in nbd_receive_replies */
 } NBDClientRequest;
 
 typedef enum NBDClientState {
@@ -73,14 +73,10 @@ typedef struct BDRVNBDState {
 
     CoMutex send_mutex;
     CoQueue free_sema;
-    Coroutine *connection_co;
-    Coroutine *teardown_co;
-    QemuCoSleep reconnect_sleep;
-    bool drained;
-    bool wait_drained_end;
+
+    CoMutex receive_mutex;
     int in_flight;
     NBDClientState state;
-    bool wait_in_flight;
 
     QEMUTimer *reconnect_delay_timer;
 
@@ -163,6 +159,8 @@ static void nbd_channel_error(BDRVNBDState *s, int ret)
     } else {
         s->state = NBD_CLIENT_QUIT;
     }
+
+    nbd_recv_coroutines_wake(s, true);
 }
 
 static void reconnect_delay_timer_del(BDRVNBDState *s)
@@ -179,6 +177,7 @@ static void reconnect_delay_timer_cb(void *opaque)
 
     if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) {
         s->state = NBD_CLIENT_CONNECTING_NOWAIT;
+        nbd_co_establish_connection_cancel(s->conn);
         while (qemu_co_enter_next(&s->free_sema, NULL)) {
             /* Resume all queued requests */
         }
@@ -201,113 +200,21 @@ static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns)
     timer_mod(s->reconnect_delay_timer, expire_time_ns);
 }
 
-static void nbd_client_detach_aio_context(BlockDriverState *bs)
-{
-    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-
-    /* Timer is deleted in nbd_client_co_drain_begin() */
-    assert(!s->reconnect_delay_timer);
-    /*
-     * If reconnect is in progress we may have no ->ioc.  It will be
-     * re-instantiated in the proper aio context once the connection is
-     * reestablished.
-     */
-    if (s->ioc) {
-        qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc));
-    }
-}
-
-static void nbd_client_attach_aio_context_bh(void *opaque)
-{
-    BlockDriverState *bs = opaque;
-    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-
-    if (s->connection_co) {
-        /*
-         * The node is still drained, so we know the coroutine has yielded in
-         * nbd_read_eof(), the only place where bs->in_flight can reach 0, or
-         * it is entered for the first time. Both places are safe for entering
-         * the coroutine.
-         */
-        qemu_aio_coroutine_enter(bs->aio_context, s->connection_co);
-    }
-    bdrv_dec_in_flight(bs);
-}
-
-static void nbd_client_attach_aio_context(BlockDriverState *bs,
-                                          AioContext *new_context)
-{
-    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-
-    /*
-     * s->connection_co is either yielded from nbd_receive_reply or from
-     * nbd_co_reconnect_loop()
-     */
-    if (nbd_client_connected(s)) {
-        qio_channel_attach_aio_context(QIO_CHANNEL(s->ioc), new_context);
-    }
-
-    bdrv_inc_in_flight(bs);
-
-    /*
-     * Need to wait here for the BH to run because the BH must run while the
-     * node is still drained.
-     */
-    aio_wait_bh_oneshot(new_context, nbd_client_attach_aio_context_bh, bs);
-}
-
-static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs)
-{
-    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-
-    s->drained = true;
-    qemu_co_sleep_wake(&s->reconnect_sleep);
-
-    nbd_co_establish_connection_cancel(s->conn);
-
-    reconnect_delay_timer_del(s);
-
-    if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) {
-        s->state = NBD_CLIENT_CONNECTING_NOWAIT;
-        qemu_co_queue_restart_all(&s->free_sema);
-    }
-}
-
-static void coroutine_fn nbd_client_co_drain_end(BlockDriverState *bs)
-{
-    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
-
-    s->drained = false;
-    if (s->wait_drained_end) {
-        s->wait_drained_end = false;
-        aio_co_wake(s->connection_co);
-    }
-}
-
-
 static void nbd_teardown_connection(BlockDriverState *bs)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
 
+    assert(!s->in_flight);
+
     if (s->ioc) {
-        /* finish any pending coroutines */
         qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+        yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name),
+                                 nbd_yank, s->bs);
+        object_unref(OBJECT(s->ioc));
+        s->ioc = NULL;
     }
 
     s->state = NBD_CLIENT_QUIT;
-    if (s->connection_co) {
-        qemu_co_sleep_wake(&s->reconnect_sleep);
-        nbd_co_establish_connection_cancel(s->conn);
-    }
-    if (qemu_in_coroutine()) {
-        s->teardown_co = qemu_coroutine_self();
-        /* connection_co resumes us when it terminates */
-        qemu_coroutine_yield();
-        s->teardown_co = NULL;
-    } else {
-        BDRV_POLL_WHILE(bs, s->connection_co);
-    }
-    assert(!s->connection_co);
 }
 
 static bool nbd_client_connecting(BDRVNBDState *s)
@@ -372,10 +279,11 @@ int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs,
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
     int ret;
+    bool blocking = nbd_client_connecting_wait(s);
 
     assert(!s->ioc);
 
-    s->ioc = nbd_co_establish_connection(s->conn, &s->info, true, errp);
+    s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp);
     if (!s->ioc) {
         return -ECONNREFUSED;
     }
@@ -411,29 +319,22 @@ int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs,
     return 0;
 }
 
+/* called under s->send_mutex */
 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
 {
-    if (!nbd_client_connecting(s)) {
-        return;
-    }
+    assert(nbd_client_connecting(s));
+    assert(s->in_flight == 0);
 
-    /* Wait for completion of all in-flight requests */
-
-    qemu_co_mutex_lock(&s->send_mutex);
-
-    while (s->in_flight > 0) {
-        qemu_co_mutex_unlock(&s->send_mutex);
-        nbd_recv_coroutines_wake(s, true);
-        s->wait_in_flight = true;
-        qemu_coroutine_yield();
-        s->wait_in_flight = false;
-        qemu_co_mutex_lock(&s->send_mutex);
-    }
-
-    qemu_co_mutex_unlock(&s->send_mutex);
-
-    if (!nbd_client_connecting(s)) {
-        return;
+    if (nbd_client_connecting_wait(s) && s->reconnect_delay &&
+        !s->reconnect_delay_timer)
+    {
+        /*
+         * It's first reconnect attempt after switching to
+         * NBD_CLIENT_CONNECTING_WAIT
+         */
+        reconnect_delay_timer_init(s,
+            qemu_clock_get_ns(QEMU_CLOCK_REALTIME) +
+            s->reconnect_delay * NANOSECONDS_PER_SECOND);
     }
 
     /*
@@ -453,135 +354,80 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
     nbd_co_do_establish_connection(s->bs, NULL);
 }
 
-static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s)
+static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle)
 {
-    uint64_t timeout = 1 * NANOSECONDS_PER_SECOND;
-    uint64_t max_timeout = 16 * NANOSECONDS_PER_SECOND;
+    int ret;
+    uint64_t ind = HANDLE_TO_INDEX(s, handle), ind2;
+    QEMU_LOCK_GUARD(&s->receive_mutex);
 
-    if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) {
-        reconnect_delay_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) +
-                                   s->reconnect_delay * NANOSECONDS_PER_SECOND);
-    }
-
-    nbd_reconnect_attempt(s);
-
-    while (nbd_client_connecting(s)) {
-        if (s->drained) {
-            bdrv_dec_in_flight(s->bs);
-            s->wait_drained_end = true;
-            while (s->drained) {
-                /*
-                 * We may be entered once from nbd_client_attach_aio_context_bh
-                 * and then from nbd_client_co_drain_end. So here is a loop.
-                 */
-                qemu_coroutine_yield();
-            }
-            bdrv_inc_in_flight(s->bs);
-        } else {
-            qemu_co_sleep_ns_wakeable(&s->reconnect_sleep,
-                                      QEMU_CLOCK_REALTIME, timeout);
-            if (s->drained) {
-                continue;
-            }
-            if (timeout < max_timeout) {
-                timeout *= 2;
-            }
-        }
-
-        nbd_reconnect_attempt(s);
-    }
-
-    reconnect_delay_timer_del(s);
-}
-
-static coroutine_fn void nbd_connection_entry(void *opaque)
-{
-    BDRVNBDState *s = opaque;
-    uint64_t i;
-    int ret = 0;
-    Error *local_err = NULL;
-
-    while (qatomic_load_acquire(&s->state) != NBD_CLIENT_QUIT) {
-        /*
-         * The NBD client can only really be considered idle when it has
-         * yielded from qio_channel_readv_all_eof(), waiting for data. This is
-         * the point where the additional scheduled coroutine entry happens
-         * after nbd_client_attach_aio_context().
-         *
-         * Therefore we keep an additional in_flight reference all the time and
-         * only drop it temporarily here.
-         */
-
-        if (nbd_client_connecting(s)) {
-            nbd_co_reconnect_loop(s);
+    while (true) {
+        if (s->reply.handle == handle) {
+            /* We are done */
+            return 0;
         }
 
         if (!nbd_client_connected(s)) {
+            return -EIO;
+        }
+
+        if (s->reply.handle != 0) {
+            /*
+             * Some other request is being handled now. It should already be
+             * woken by whoever set s->reply.handle (or never wait in this
+             * yield). So, we should not wake it here.
+             */
+            ind2 = HANDLE_TO_INDEX(s, s->reply.handle);
+            assert(!s->requests[ind2].receiving);
+
+            s->requests[ind].receiving = true;
+            qemu_co_mutex_unlock(&s->receive_mutex);
+
+            qemu_coroutine_yield();
+            /*
+             * We may be woken for 3 reasons:
+             * 1. From this function, executing in parallel coroutine, when our
+             *    handle is received.
+             * 2. From nbd_channel_error(), when connection is lost.
+             * 3. From nbd_co_receive_one_chunk(), when previous request is
+             *    finished and s->reply.handle set to 0.
+             * Anyway, it's OK to lock the mutex and go to the next iteration.
+             */
+
+            qemu_co_mutex_lock(&s->receive_mutex);
+            assert(!s->requests[ind].receiving);
             continue;
         }
 
+        /* We are under mutex and handle is 0. We have to do the dirty work. */
         assert(s->reply.handle == 0);
-        ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, &local_err);
-
-        if (local_err) {
-            trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err));
-            error_free(local_err);
-            local_err = NULL;
-        }
+        ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL);
         if (ret <= 0) {
-            nbd_channel_error(s, ret ? ret : -EIO);
-            continue;
+            ret = ret ? ret : -EIO;
+            nbd_channel_error(s, ret);
+            return ret;
         }
-
-        /*
-         * There's no need for a mutex on the receive side, because the
-         * handler acts as a synchronization point and ensures that only
-         * one coroutine is called until the reply finishes.
-         */
-        i = HANDLE_TO_INDEX(s, s->reply.handle);
-        if (i >= MAX_NBD_REQUESTS ||
-            !s->requests[i].coroutine ||
-            !s->requests[i].receiving ||
-            (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply))
-        {
+        if (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply) {
             nbd_channel_error(s, -EINVAL);
-            continue;
+            return -EINVAL;
         }
-
-        /*
-         * We're woken up again by the request itself.  Note that there
-         * is no race between yielding and reentering connection_co.  This
-         * is because:
-         *
-         * - if the request runs on the same AioContext, it is only
-         *   entered after we yield
-         *
-         * - if the request runs on a different AioContext, reentering
-         *   connection_co happens through a bottom half, which can only
-         *   run after we yield.
-         */
-        s->requests[i].receiving = false;
-        aio_co_wake(s->requests[i].coroutine);
-        qemu_coroutine_yield();
+        if (s->reply.handle == handle) {
+            /* We are done */
+            return 0;
+        }
+        ind2 = HANDLE_TO_INDEX(s, s->reply.handle);
+        if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) {
+            /*
+             * We only check that ind2 request exists. But don't check
+             * whether it is now waiting for the reply header or
+             * not. We can't just check s->requests[ind2].receiving:
+             * ind2 request may wait in trying to lock
+             * receive_mutex. So that's a TODO.
+             */
+            nbd_channel_error(s, -EINVAL);
+            return -EINVAL;
+        }
+        nbd_recv_coroutine_wake_one(&s->requests[ind2]);
     }
-
-    qemu_co_queue_restart_all(&s->free_sema);
-    nbd_recv_coroutines_wake(s, true);
-    bdrv_dec_in_flight(s->bs);
-
-    s->connection_co = NULL;
-    if (s->ioc) {
-        qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc));
-        yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name),
-                                 nbd_yank, s->bs);
-        object_unref(OBJECT(s->ioc));
-        s->ioc = NULL;
-    }
-
-    if (s->teardown_co) {
-        aio_co_wake(s->teardown_co);
-    }
-    aio_wait_kick();
 }
 
 static int nbd_co_send_request(BlockDriverState *bs,
@@ -592,10 +438,17 @@ static int nbd_co_send_request(BlockDriverState *bs,
     int rc, i = -1;
 
     qemu_co_mutex_lock(&s->send_mutex);
-    while (s->in_flight == MAX_NBD_REQUESTS || nbd_client_connecting_wait(s)) {
+
+    while (s->in_flight == MAX_NBD_REQUESTS ||
+           (!nbd_client_connected(s) && s->in_flight > 0))
+    {
         qemu_co_queue_wait(&s->free_sema, &s->send_mutex);
     }
 
+    if (nbd_client_connecting(s)) {
+        nbd_reconnect_attempt(s);
+    }
+
     if (!nbd_client_connected(s)) {
         rc = -EIO;
         goto err;
@@ -642,10 +495,6 @@ err:
         if (i != -1) {
             s->requests[i].coroutine = NULL;
             s->in_flight--;
-        }
-        if (s->in_flight == 0 && s->wait_in_flight) {
-            aio_co_wake(s->connection_co);
-        } else {
             qemu_co_queue_next(&s->free_sema);
         }
     }
@@ -944,10 +793,7 @@ static coroutine_fn int nbd_co_do_receive_one_chunk(
     }
     *request_ret = 0;
 
-    /* Wait until we're woken up by nbd_connection_entry.  */
-    s->requests[i].receiving = true;
-    qemu_coroutine_yield();
-    assert(!s->requests[i].receiving);
+    nbd_receive_replies(s, handle);
     if (!nbd_client_connected(s)) {
         error_setg(errp, "Connection closed");
         return -EIO;
@@ -1040,14 +886,7 @@ static coroutine_fn int nbd_co_receive_one_chunk(
     }
     s->reply.handle = 0;
 
-    if (s->connection_co && !s->wait_in_flight) {
-        /*
-         * We must check s->wait_in_flight, because we may entered by
-         * nbd_recv_coroutines_wake(), in this case we should not
-         * wake connection_co here, it will woken by last request.
-         */
-        aio_co_wake(s->connection_co);
-    }
+    nbd_recv_coroutines_wake(s, false);
 
     return ret;
 }
@@ -1158,11 +997,7 @@ break_loop:
 
     qemu_co_mutex_lock(&s->send_mutex);
     s->in_flight--;
-    if (s->in_flight == 0 && s->wait_in_flight) {
-        aio_co_wake(s->connection_co);
-    } else {
-        qemu_co_queue_next(&s->free_sema);
-    }
+    qemu_co_queue_next(&s->free_sema);
     qemu_co_mutex_unlock(&s->send_mutex);
 
     return false;
@@ -1984,6 +1819,7 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
     s->bs = bs;
     qemu_co_mutex_init(&s->send_mutex);
     qemu_co_queue_init(&s->free_sema);
+    qemu_co_mutex_init(&s->receive_mutex);
 
     if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) {
         return -EEXIST;
@@ -1998,14 +1834,13 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
                                         s->x_dirty_bitmap, s->tlscreds);
 
     /* TODO: Configurable retry-until-timeout behaviour. */
+    s->state = NBD_CLIENT_CONNECTING_WAIT;
     ret = nbd_do_establish_connection(bs, errp);
     if (ret < 0) {
         goto fail;
     }
 
-    s->connection_co = qemu_coroutine_create(nbd_connection_entry, s);
-    bdrv_inc_in_flight(bs);
-    aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co);
+    nbd_client_connection_enable_retry(s->conn);
 
     return 0;
 
@@ -2159,6 +1994,8 @@ static void nbd_cancel_in_flight(BlockDriverState *bs)
         s->state = NBD_CLIENT_CONNECTING_NOWAIT;
         qemu_co_queue_restart_all(&s->free_sema);
     }
+
+    nbd_co_establish_connection_cancel(s->conn);
 }
 
 static BlockDriver bdrv_nbd = {
@@ -2179,10 +2016,6 @@ static BlockDriver bdrv_nbd = {
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_co_truncate           = nbd_co_truncate,
     .bdrv_getlength             = nbd_getlength,
-    .bdrv_detach_aio_context    = nbd_client_detach_aio_context,
-    .bdrv_attach_aio_context    = nbd_client_attach_aio_context,
-    .bdrv_co_drain_begin        = nbd_client_co_drain_begin,
-    .bdrv_co_drain_end          = nbd_client_co_drain_end,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
@@ -2208,10 +2041,6 @@ static BlockDriver bdrv_nbd_tcp = {
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_co_truncate           = nbd_co_truncate,
     .bdrv_getlength             = nbd_getlength,
-    .bdrv_detach_aio_context    = nbd_client_detach_aio_context,
-    .bdrv_attach_aio_context    = nbd_client_attach_aio_context,
-    .bdrv_co_drain_begin        = nbd_client_co_drain_begin,
-    .bdrv_co_drain_end          = nbd_client_co_drain_end,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
@@ -2237,10 +2066,6 @@ static BlockDriver bdrv_nbd_unix = {
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_co_truncate           = nbd_co_truncate,
     .bdrv_getlength             = nbd_getlength,
-    .bdrv_detach_aio_context    = nbd_client_detach_aio_context,
-    .bdrv_attach_aio_context    = nbd_client_attach_aio_context,
-    .bdrv_co_drain_begin        = nbd_client_co_drain_begin,
-    .bdrv_co_drain_end          = nbd_client_co_drain_end,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
diff --git a/nbd/client.c b/nbd/client.c
index 0c2db4bcba..30d5383cb1 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -1434,9 +1434,7 @@ nbd_read_eof(BlockDriverState *bs, QIOChannel *ioc, void *buffer, size_t size,
 
         len = qio_channel_readv(ioc, &iov, 1, errp);
         if (len == QIO_CHANNEL_ERR_BLOCK) {
-            bdrv_dec_in_flight(bs);
             qio_channel_yield(ioc, G_IO_IN);
-            bdrv_inc_in_flight(bs);
             continue;
         } else if (len < 0) {
             return -EIO;

From 1af7737871fb3b66036f5e520acb0a98fc2605f7 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Thu, 2 Sep 2021 13:38:05 +0300
Subject: [PATCH 19/19] block/nbd: check that received handle is valid

If we don't have active request, that waiting for this handle to be
received, we should report an error.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210902103805.25686-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/nbd.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index 8ff6daf43d..5ef462db1b 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -58,6 +58,7 @@ typedef struct {
     Coroutine *coroutine;
     uint64_t offset;        /* original offset of the request */
     bool receiving;         /* sleeping in the yield in nbd_receive_replies */
+    bool reply_possible;    /* reply header not yet received */
 } NBDClientRequest;
 
 typedef enum NBDClientState {
@@ -415,14 +416,7 @@ static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle)
             return 0;
         }
         ind2 = HANDLE_TO_INDEX(s, s->reply.handle);
-        if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) {
-            /*
-             * We only check that ind2 request exists. But don't check
-             * whether it is now waiting for the reply header or
-             * not. We can't just check s->requests[ind2].receiving:
-             * ind2 request may wait in trying to lock
-             * receive_mutex. So that's a TODO.
-             */
+        if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].reply_possible) {
             nbd_channel_error(s, -EINVAL);
             return -EINVAL;
         }
@@ -468,6 +462,7 @@ static int nbd_co_send_request(BlockDriverState *bs,
     s->requests[i].coroutine = qemu_coroutine_self();
     s->requests[i].offset = request->from;
     s->requests[i].receiving = false;
+    s->requests[i].reply_possible = true;
 
     request->handle = INDEX_TO_HANDLE(s, i);