diff options
Diffstat (limited to 'block/io.c')
| -rw-r--r-- | block/io.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/block/io.c b/block/io.c index 1fb7afeaf0..cd6d71a503 100644 --- a/block/io.c +++ b/block/io.c @@ -652,7 +652,8 @@ int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, * Completely zero out a block device with the help of bdrv_write_zeroes. * The operation is sped up by checking the block status and only writing * zeroes to the device if they currently do not return zeroes. Optional - * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). + * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP, + * BDRV_REQ_FUA). * * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). */ @@ -1160,6 +1161,7 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, QEMUIOVector qiov; struct iovec iov = {0}; int ret = 0; + bool need_flush = false; int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes, BDRV_REQUEST_MAX_SECTORS); @@ -1192,13 +1194,29 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, ret = -ENOTSUP; /* First try the efficient write zeroes operation */ if (drv->bdrv_co_write_zeroes) { - ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); + ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, + flags & bs->supported_zero_flags); + if (ret != -ENOTSUP && (flags & BDRV_REQ_FUA) && + !(bs->supported_zero_flags & BDRV_REQ_FUA)) { + need_flush = true; + } + } else { + assert(!bs->supported_zero_flags); } if (ret == -ENOTSUP) { /* Fall back to bounce buffer if write zeroes is unsupported */ int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length, MAX_WRITE_ZEROES_BOUNCE_BUFFER); + BdrvRequestFlags write_flags = flags & ~BDRV_REQ_ZERO_WRITE; + + if ((flags & BDRV_REQ_FUA) && + !(bs->supported_write_flags & BDRV_REQ_FUA)) { + /* No need for bdrv_driver_pwrite() to do a fallback + * flush on each chunk; use just one at the end */ + write_flags &= ~BDRV_REQ_FUA; + need_flush = true; + } num = MIN(num, max_xfer_len); iov.iov_len = num * BDRV_SECTOR_SIZE; if (iov.iov_base == NULL) { @@ -1212,7 +1230,8 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, qemu_iovec_init_external(&qiov, &iov, 1); ret = bdrv_driver_pwritev(bs, sector_num * BDRV_SECTOR_SIZE, - num * BDRV_SECTOR_SIZE, &qiov, 0); + num * BDRV_SECTOR_SIZE, &qiov, + write_flags); /* Keep bounce buffer around if it is big enough for all * all future requests. @@ -1228,6 +1247,9 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, } fail: + if (ret == 0 && need_flush) { + ret = bdrv_co_flush(bs); + } qemu_vfree(iov.iov_base); return ret; } |