[PATCH v3 06/17] block/io: support int64_t bytes in bdrv_aligned_pwritev()

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

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, prepare bdrv_aligned_pwritev() now and convert the dependencies:
bdrv_co_write_req_prepare() and bdrv_co_write_req_finish() to signed
type bytes.

Series: 64bit-block-status
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/io.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/block/io.c b/block/io.c
index b83749cc50..8bb4ea6285 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1686,12 +1686,11 @@ fail:
 }
 
 static inline int coroutine_fn
-bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
+bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, int64_t bytes,
                           BdrvTrackedRequest *req, int flags)
 {
     BlockDriverState *bs = child->bs;
     bool waited;
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
 
     if (bs->read_only) {
         return -EPERM;
@@ -1716,8 +1715,10 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
     }
 
     assert(req->overlap_offset <= offset);
+    assert(offset <= INT64_MAX - bytes);
     assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
-    assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE);
+    assert(offset + bytes <= bs->total_sectors * BDRV_SECTOR_SIZE ||
+           child->perm & BLK_PERM_RESIZE);
 
     switch (req->type) {
     case BDRV_TRACKED_WRITE:
@@ -1738,7 +1739,7 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
 }
 
 static inline void coroutine_fn
-bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes,
+bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, int64_t bytes,
                          BdrvTrackedRequest *req, int ret)
 {
     int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
@@ -1780,14 +1781,14 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes,
  * after possibly fragmenting it.
  */
 static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
-    BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
+    BdrvTrackedRequest *req, int64_t offset, int64_t bytes,
     int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags)
 {
     BlockDriverState *bs = child->bs;
     BlockDriver *drv = bs->drv;
     int ret;
 
-    uint64_t bytes_remaining = bytes;
+    int64_t bytes_remaining = bytes;
     int max_transfer;
 
     if (!drv) {
@@ -1799,6 +1800,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
     }
 
     assert(is_power_of_2(align));
+    assert(offset >= 0);
+    assert(bytes >= 0);
     assert((offset & (align - 1)) == 0);
     assert((bytes & (align - 1)) == 0);
     assert(!qiov || qiov_offset + bytes <= qiov->size);
@@ -1899,7 +1902,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
     assert(!bytes || (offset & (align - 1)) == 0);
     if (bytes >= align) {
         /* Write the aligned part in the middle. */
-        uint64_t aligned_bytes = bytes & ~(align - 1);
+        int64_t aligned_bytes = bytes & ~(align - 1);
         ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align,
                                    NULL, 0, flags);
         if (ret < 0) {
-- 
2.21.0