diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/io.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/block/io.c b/block/io.c index c3574a4dd6..410394dc42 100644 --- a/block/io.c +++ b/block/io.c @@ -1269,7 +1269,8 @@ fail: } /* - * 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, @@ -1281,6 +1282,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, 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); @@ -1288,6 +1291,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, 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); @@ -1310,9 +1315,34 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, } 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); @@ -1325,6 +1355,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, if (ret >= 0) { bs->total_sectors = MAX(bs->total_sectors, end_sector); + ret = 0; } return ret; |