Message ID | 1469175475-15420-5-git-send-email-den@openvz.org |
---|---|
State | New |
Headers | show |
Am 22.07.2016 um 10:17 hat Denis V. Lunev geschrieben: > From: Pavel Butsykin <pbutsykin@virtuozzo.com> > > Added implementation of the qcow2_co_pwritev_compressed function that > will allow us to safely use compressed writes for the qcow2 from running > VMs. > > Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > Signed-off-by: Denis V. Lunev <den@openvz.org> > CC: Jeff Cody <jcody@redhat.com> > CC: Markus Armbruster <armbru@redhat.com> > CC: Eric Blake <eblake@redhat.com> > CC: John Snow <jsnow@redhat.com> > CC: Stefan Hajnoczi <stefanha@redhat.com> > CC: Kevin Wolf <kwolf@redhat.com> > /* XXX: put compressed sectors first, then all the cluster aligned > tables to avoid losing bytes in alignment */ > -static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, > - const uint8_t *buf, int nb_sectors) > +static coroutine_fn int > +qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, > + uint64_t bytes, QEMUIOVector *qiov) > { > BDRVQcow2State *s = bs->opaque; > + QEMUIOVector hd_qiov; > + struct iovec iov; > z_stream strm; > int ret, out_len; > - uint8_t *out_buf; > + uint8_t *buf, *out_buf; > uint64_t cluster_offset; > > - if (nb_sectors == 0) { > + if (bytes == 0) { > /* align end of file to a sector boundary to ease reading with > sector based I/Os */ > cluster_offset = bdrv_getlength(bs->file->bs); > return bdrv_truncate(bs->file->bs, cluster_offset); > } > > - if (nb_sectors != s->cluster_sectors) { > + if (bytes != s->cluster_size) { > ret = -EINVAL; > > /* Zero-pad last write if image size is not cluster aligned */ > - if (sector_num + nb_sectors == bs->total_sectors && > - nb_sectors < s->cluster_sectors) { > + if (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS && > + bytes < s->cluster_size) > + { > uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); > memset(pad_buf, 0, s->cluster_size); > - memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); > - ret = qcow2_write_compressed(bs, sector_num, > - pad_buf, s->cluster_sectors); > + qemu_iovec_to_buf(qiov, 0, pad_buf, s->cluster_size); I think, bytes would be more exact than s->cluster_size here. Anyway, shouldn't hurt because we stop at the end of the qiov anyway and its size should match bytes. > + iov = (struct iovec) { > + .iov_base = pad_buf, > + .iov_len = s->cluster_size, > + }; > + qemu_iovec_init_external(&hd_qiov, &iov, 1); > + ret = qcow2_co_pwritev_compressed(bs, offset, bytes, &hd_qiov); > qemu_vfree(pad_buf); > } > return ret; > } Kevin
On 08.08.2016 16:44, Kevin Wolf wrote: > Am 22.07.2016 um 10:17 hat Denis V. Lunev geschrieben: >> From: Pavel Butsykin <pbutsykin@virtuozzo.com> >> >> Added implementation of the qcow2_co_pwritev_compressed function that >> will allow us to safely use compressed writes for the qcow2 from running >> VMs. >> >> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> >> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> >> Signed-off-by: Denis V. Lunev <den@openvz.org> >> CC: Jeff Cody <jcody@redhat.com> >> CC: Markus Armbruster <armbru@redhat.com> >> CC: Eric Blake <eblake@redhat.com> >> CC: John Snow <jsnow@redhat.com> >> CC: Stefan Hajnoczi <stefanha@redhat.com> >> CC: Kevin Wolf <kwolf@redhat.com> > >> /* XXX: put compressed sectors first, then all the cluster aligned >> tables to avoid losing bytes in alignment */ >> -static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, >> - const uint8_t *buf, int nb_sectors) >> +static coroutine_fn int >> +qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, >> + uint64_t bytes, QEMUIOVector *qiov) >> { >> BDRVQcow2State *s = bs->opaque; >> + QEMUIOVector hd_qiov; >> + struct iovec iov; >> z_stream strm; >> int ret, out_len; >> - uint8_t *out_buf; >> + uint8_t *buf, *out_buf; >> uint64_t cluster_offset; >> >> - if (nb_sectors == 0) { >> + if (bytes == 0) { >> /* align end of file to a sector boundary to ease reading with >> sector based I/Os */ >> cluster_offset = bdrv_getlength(bs->file->bs); >> return bdrv_truncate(bs->file->bs, cluster_offset); >> } >> >> - if (nb_sectors != s->cluster_sectors) { >> + if (bytes != s->cluster_size) { >> ret = -EINVAL; >> >> /* Zero-pad last write if image size is not cluster aligned */ >> - if (sector_num + nb_sectors == bs->total_sectors && >> - nb_sectors < s->cluster_sectors) { >> + if (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS && >> + bytes < s->cluster_size) >> + { >> uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); >> memset(pad_buf, 0, s->cluster_size); >> - memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); >> - ret = qcow2_write_compressed(bs, sector_num, >> - pad_buf, s->cluster_sectors); >> + qemu_iovec_to_buf(qiov, 0, pad_buf, s->cluster_size); > > I think, bytes would be more exact than s->cluster_size here. Anyway, > shouldn't hurt because we stop at the end of the qiov anyway and its > size should match bytes. Yes, I can send follow-up patches. > >> + iov = (struct iovec) { >> + .iov_base = pad_buf, >> + .iov_len = s->cluster_size, >> + }; >> + qemu_iovec_init_external(&hd_qiov, &iov, 1); >> + ret = qcow2_co_pwritev_compressed(bs, offset, bytes, &hd_qiov); >> qemu_vfree(pad_buf); >> } >> return ret; >> } > > Kevin >
Am 15.08.2016 um 11:39 hat Pavel Butsykin geschrieben: > Use bytes as the size would be more exact than s->cluster_size. Although > qemu_iovec_to_buf() will not allow to go beyond the qiov. > > Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Thanks, applied to block-next. Kevin
diff --git a/block/qcow2.c b/block/qcow2.c index d620d0a..b5c69df 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2533,84 +2533,49 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset) return 0; } -typedef struct Qcow2WriteCo { - BlockDriverState *bs; - int64_t sector_num; - const uint8_t *buf; - int nb_sectors; - int ret; -} Qcow2WriteCo; - -static void qcow2_write_co_entry(void *opaque) -{ - Qcow2WriteCo *co = opaque; - QEMUIOVector qiov; - uint64_t offset = co->sector_num * BDRV_SECTOR_SIZE; - uint64_t bytes = co->nb_sectors * BDRV_SECTOR_SIZE; - - struct iovec iov = (struct iovec) { - .iov_base = (uint8_t*) co->buf, - .iov_len = bytes, - }; - qemu_iovec_init_external(&qiov, &iov, 1); - - co->ret = qcow2_co_pwritev(co->bs, offset, bytes, &qiov, 0); -} - -/* Wrapper for non-coroutine contexts */ -static int qcow2_write(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) -{ - Coroutine *co; - AioContext *aio_context = bdrv_get_aio_context(bs); - Qcow2WriteCo data = { - .bs = bs, - .sector_num = sector_num, - .buf = buf, - .nb_sectors = nb_sectors, - .ret = -EINPROGRESS, - }; - co = qemu_coroutine_create(qcow2_write_co_entry, &data); - qemu_coroutine_enter(co); - while (data.ret == -EINPROGRESS) { - aio_poll(aio_context, true); - } - return data.ret; -} - /* XXX: put compressed sectors first, then all the cluster aligned tables to avoid losing bytes in alignment */ -static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) +static coroutine_fn int +qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, QEMUIOVector *qiov) { BDRVQcow2State *s = bs->opaque; + QEMUIOVector hd_qiov; + struct iovec iov; z_stream strm; int ret, out_len; - uint8_t *out_buf; + uint8_t *buf, *out_buf; uint64_t cluster_offset; - if (nb_sectors == 0) { + if (bytes == 0) { /* align end of file to a sector boundary to ease reading with sector based I/Os */ cluster_offset = bdrv_getlength(bs->file->bs); return bdrv_truncate(bs->file->bs, cluster_offset); } - if (nb_sectors != s->cluster_sectors) { + if (bytes != s->cluster_size) { ret = -EINVAL; /* Zero-pad last write if image size is not cluster aligned */ - if (sector_num + nb_sectors == bs->total_sectors && - nb_sectors < s->cluster_sectors) { + if (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS && + bytes < s->cluster_size) + { uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); memset(pad_buf, 0, s->cluster_size); - memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); - ret = qcow2_write_compressed(bs, sector_num, - pad_buf, s->cluster_sectors); + qemu_iovec_to_buf(qiov, 0, pad_buf, s->cluster_size); + iov = (struct iovec) { + .iov_base = pad_buf, + .iov_len = s->cluster_size, + }; + qemu_iovec_init_external(&hd_qiov, &iov, 1); + ret = qcow2_co_pwritev_compressed(bs, offset, bytes, &hd_qiov); qemu_vfree(pad_buf); } return ret; } + buf = qemu_blockalign(bs, s->cluster_size); + qemu_iovec_to_buf(qiov, 0, buf, s->cluster_size); out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); @@ -2641,33 +2606,44 @@ static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, if (ret != Z_STREAM_END || out_len >= s->cluster_size) { /* could not compress: write normal cluster */ - ret = qcow2_write(bs, sector_num, buf, s->cluster_sectors); + ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0); if (ret < 0) { goto fail; } - } else { - cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, - sector_num << 9, out_len); - if (!cluster_offset) { - ret = -EIO; - goto fail; - } - cluster_offset &= s->cluster_offset_mask; + goto success; + } - ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len); - if (ret < 0) { - goto fail; - } + qemu_co_mutex_lock(&s->lock); + cluster_offset = + qcow2_alloc_compressed_cluster_offset(bs, offset, out_len); + if (!cluster_offset) { + qemu_co_mutex_unlock(&s->lock); + ret = -EIO; + goto fail; + } + cluster_offset &= s->cluster_offset_mask; - BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); - ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); - if (ret < 0) { - goto fail; - } + ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len); + qemu_co_mutex_unlock(&s->lock); + if (ret < 0) { + goto fail; } + iov = (struct iovec) { + .iov_base = out_buf, + .iov_len = out_len, + }; + qemu_iovec_init_external(&hd_qiov, &iov, 1); + + BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); + ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0); + if (ret < 0) { + goto fail; + } +success: ret = 0; fail: + qemu_vfree(buf); g_free(out_buf); return ret; } @@ -3412,7 +3388,7 @@ BlockDriver bdrv_qcow2 = { .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, .bdrv_co_pdiscard = qcow2_co_pdiscard, .bdrv_truncate = qcow2_truncate, - .bdrv_write_compressed = qcow2_write_compressed, + .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed, .bdrv_make_empty = qcow2_make_empty, .bdrv_snapshot_create = qcow2_snapshot_create,