block/io: support int64_t bytes in read/write wrappers

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).

Now, since bdrv_co_preadv_part() and bdrv_co_pwritev_part() have been
updated, update all their wrappers.

For all of them type of 'bytes' is widening, so callers are safe. We
have update request_fn in blkverify.c simultaneously. Still it's just a
pointer to one of bdrv_co_pwritev() or bdrv_co_preadv(), and type is
widening for callers of the request_fn anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-16-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>

block/blkverify.c

@@ -31,7 +31,7 @@ typedef struct BlkverifyRequest {
     uint64_t bytes;
     int flags;
 
-    int (*request_fn)(BdrvChild *, int64_t, unsigned int, QEMUIOVector *,
+    int (*request_fn)(BdrvChild *, int64_t, int64_t, QEMUIOVector *,
                       BdrvRequestFlags);
 
     int ret;                    /* test image result */

block/io.c

@@ -1005,7 +1005,7 @@ static int bdrv_check_request32(int64_t offset, int64_t bytes,
 }
 
 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                       int bytes, BdrvRequestFlags flags)
+                       int64_t bytes, BdrvRequestFlags flags)
 {
     return bdrv_pwritev(child, offset, bytes, NULL,
                         BDRV_REQ_ZERO_WRITE | flags);
@@ -1053,7 +1053,7 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
 }
 
 /* See bdrv_pwrite() for the return codes */
-int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes)
+int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes)
 {
     int ret;
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
@@ -1073,7 +1073,8 @@ int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes)
   -EINVAL      Invalid offset or number of bytes
   -EACCES      Trying to write a read-only device
 */
-int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes)
+int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf,
+                int64_t bytes)
 {
     int ret;
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
@@ -1094,7 +1095,7 @@ int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes)
  * Returns 0 on success, -errno in error cases.
  */
 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
-                     const void *buf, int count)
+                     const void *buf, int64_t count)
 {
     int ret;
 
@@ -1759,7 +1760,7 @@ static int bdrv_pad_request(BlockDriverState *bs,
 }
 
 int coroutine_fn bdrv_co_preadv(BdrvChild *child,
-    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags)
 {
     return bdrv_co_preadv_part(child, offset, bytes, qiov, 0, flags);
@@ -2186,7 +2187,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
  * Handle a write request in coroutine context
  */
 int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
-    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags)
 {
     return bdrv_co_pwritev_part(child, offset, bytes, qiov, 0, flags);
@@ -2279,7 +2280,7 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
 }
 
 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                                       int bytes, BdrvRequestFlags flags)
+                                       int64_t bytes, BdrvRequestFlags flags)
 {
     trace_bdrv_co_pwrite_zeroes(child->bs, offset, bytes, flags);
 

block/trace-events

@@ -13,7 +13,7 @@ blk_root_detach(void *child, void *blk, void *bs) "child %p blk %p bs %p"
 # io.c
 bdrv_co_preadv_part(void *bs, int64_t offset, int64_t bytes, unsigned int flags) "bs %p offset %" PRId64 " bytes %" PRId64 " flags 0x%x"
 bdrv_co_pwritev_part(void *bs, int64_t offset, int64_t bytes, unsigned int flags) "bs %p offset %" PRId64 " bytes %" PRId64 " flags 0x%x"
-bdrv_co_pwrite_zeroes(void *bs, int64_t offset, int count, int flags) "bs %p offset %"PRId64" count %d flags 0x%x"
+bdrv_co_pwrite_zeroes(void *bs, int64_t offset, int64_t bytes, int flags) "bs %p offset %" PRId64 " bytes %" PRId64 " flags 0x%x"
 bdrv_co_do_copy_on_readv(void *bs, int64_t offset, int64_t bytes, int64_t cluster_offset, int64_t cluster_bytes) "bs %p offset %" PRId64 " bytes %" PRId64 " cluster_offset %" PRId64 " cluster_bytes %" PRId64
 bdrv_co_copy_range_from(void *src, uint64_t src_offset, void *dst, uint64_t dst_offset, uint64_t bytes, int read_flags, int write_flags) "src %p offset %"PRIu64" dst %p offset %"PRIu64" bytes %"PRIu64" rw flags 0x%x 0x%x"
 bdrv_co_copy_range_to(void *src, uint64_t src_offset, void *dst, uint64_t dst_offset, uint64_t bytes, int read_flags, int write_flags) "src %p offset %"PRIu64" dst %p offset %"PRIu64" bytes %"PRIu64" rw flags 0x%x 0x%x"

include/block/block.h

@@ -392,20 +392,21 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                       int bytes, BdrvRequestFlags flags);
+                       int64_t bytes, BdrvRequestFlags flags);
 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
-int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
-int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
+int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes);
+int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf,
+                int64_t bytes);
 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
-                     const void *buf, int count);
+                     const void *buf, int64_t bytes);
 /*
  * Efficiently zero a region of the disk image.  Note that this is a regular
  * I/O request like read or write and should have a reasonable size.  This
  * function is not suitable for zeroing the entire image in a single request
  * because it may allocate memory for the entire region.
  */
 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                                       int bytes, BdrvRequestFlags flags);
+                                       int64_t bytes, BdrvRequestFlags flags);
 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
     const char *backing_file);
 void bdrv_refresh_filename(BlockDriverState *bs);

include/block/block_int.h

@@ -1032,13 +1032,13 @@ extern BlockDriver bdrv_raw;
 extern BlockDriver bdrv_qcow2;
 
 int coroutine_fn bdrv_co_preadv(BdrvChild *child,
-    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags);
 int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
     int64_t offset, int64_t bytes,
     QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
 int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
-    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+    int64_t offset, int64_t bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags);
 int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
     int64_t offset, int64_t bytes,