}
/*
- * Forwards an already correctly aligned write request to the BlockDriver.
+ * Forwards an already correctly aligned write request to the BlockDriver,
+ * after possibly fragmenting it.
*/
static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
int64_t start_sector = offset >> BDRV_SECTOR_BITS;
int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
+ uint64_t bytes_remaining = bytes;
+ int max_transfer;
assert(is_power_of_2(align));
assert((offset & (align - 1)) == 0);
assert(!qiov || bytes == qiov->size);
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
assert(!(flags & ~BDRV_REQ_MASK));
+ max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX),
+ align);
waited = wait_serialising_requests(req);
assert(!waited || !req->serialising);
} else if (flags & BDRV_REQ_ZERO_WRITE) {
bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags);
- } else {
+ } else if (bytes <= max_transfer) {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags);
+ } else {
+ bdrv_debug_event(bs, BLKDBG_PWRITEV);
+ while (bytes_remaining) {
+ int num = MIN(bytes_remaining, max_transfer);
+ QEMUIOVector local_qiov;
+ int local_flags = flags;
+
+ assert(num);
+ if (num < bytes_remaining && (flags & BDRV_REQ_FUA) &&
+ !(bs->supported_write_flags & BDRV_REQ_FUA)) {
+ /* If FUA is going to be emulated by flush, we only
+ * need to flush on the last iteration */
+ local_flags &= ~BDRV_REQ_FUA;
+ }
+ qemu_iovec_init(&local_qiov, qiov->niov);
+ qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num);
+
+ ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining,
+ num, &local_qiov, local_flags);
+ qemu_iovec_destroy(&local_qiov);
+ if (ret < 0) {
+ break;
+ }
+ bytes_remaining -= num;
+ }
}
bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
if (ret >= 0) {
bs->total_sectors = MAX(bs->total_sectors, end_sector);
+ ret = 0;
}
return ret;