diff options
| -rw-r--r-- | block/io.c | 28 | ||||
| -rw-r--r-- | block/iscsi.c | 1 | ||||
| -rw-r--r-- | block/raw-posix.c | 1 | ||||
| -rw-r--r-- | block/raw_bsd.c | 1 | ||||
| -rw-r--r-- | include/block/block_int.h | 7 |
5 files changed, 33 insertions, 5 deletions
@@ -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; } diff --git a/block/iscsi.c b/block/iscsi.c index 6d5c1f6..10f3906 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1553,6 +1553,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, if (iscsilun->dpofua) { bs->supported_write_flags = BDRV_REQ_FUA; } + bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP; /* Check the write protect flag of the LUN if we want to write */ if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) && diff --git a/block/raw-posix.c b/block/raw-posix.c index 71ec463..a4f5a1b 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -517,6 +517,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->has_discard = true; s->has_write_zeroes = true; + bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP; if ((bs->open_flags & BDRV_O_NOCACHE) != 0) { s->needs_alignment = true; } diff --git a/block/raw_bsd.c b/block/raw_bsd.c index 1a1618e..3385ed4 100644 --- a/block/raw_bsd.c +++ b/block/raw_bsd.c @@ -205,6 +205,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, { bs->sg = bs->file->bs->sg; bs->supported_write_flags = BDRV_REQ_FUA; + bs->supported_zero_flags = BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP; if (bs->probed && !bdrv_is_read_only(bs)) { fprintf(stderr, diff --git a/include/block/block_int.h b/include/block/block_int.h index 10f4962..2709488 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -161,8 +161,8 @@ struct BlockDriver { /* * Efficiently zero a region of the disk image. Typically an image format * would use a compact metadata representation to implement this. This - * function pointer may be NULL and .bdrv_co_writev() will be called - * instead. + * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev() + * will be called instead. */ int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); @@ -445,6 +445,9 @@ struct BlockDriverState { unsigned int request_alignment; /* Flags honored during pwrite (so far: BDRV_REQ_FUA) */ unsigned int supported_write_flags; + /* Flags honored during write_zeroes (so far: BDRV_REQ_FUA, + * BDRV_REQ_MAY_UNMAP) */ + unsigned int supported_zero_flags; /* the following member gives a name to every node on the bs graph. */ char node_name[32]; |