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

@@ -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;
 

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);
 }

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);

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;

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;

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;

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);
 }

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);
 }

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;

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 */

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(),

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;

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);
 }

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;

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);

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);
 }

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;

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;

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)
 {

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);
 }