From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55277) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7Ai2-0005d3-MS for qemu-devel@nongnu.org; Mon, 12 Mar 2012 15:15:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7Ahf-0005Sq-Ua for qemu-devel@nongnu.org; Mon, 12 Mar 2012 15:15:06 -0400 Received: from isrv.corpit.ru ([86.62.121.231]:51238) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7Ahf-0005S9-IR for qemu-devel@nongnu.org; Mon, 12 Mar 2012 15:14:43 -0400 From: Michael Tokarev Date: Mon, 12 Mar 2012 23:14:18 +0400 Message-Id: <1331579663-29950-5-git-send-email-mjt@msgid.tls.msk.ru> In-Reply-To: <1331579663-29950-1-git-send-email-mjt@msgid.tls.msk.ru> References: <1331579663-29950-1-git-send-email-mjt@msgid.tls.msk.ru> Subject: [Qemu-devel] [PATCHv3 4/9] consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Michael Tokarev qemu_iovec_concat() is currently a wrapper for qemu_iovec_copy(), use the former (with extra "0" arg) in a few places where it is used. Change skip argument of qemu_iovec_copy() from uint64_t to size_t, since size of qiov itself is size_t, so there's no way to skip larger sizes. Rename it to soffset, to make it clear that the offset is applied to src. Also change the only usage of uint64_t in hw/9pfs/virtio-9p.c, in v9fs_init_qiov_from_pdu() - all callers of it actually uses size_t too, not uint64_t. One added restriction: as for all other iovec-related functions, soffset must point inside src. Order of argumens is already good: qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, int c, size_t bytes) vs: qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t soffset, size_t sbytes) (note soffset is after _src_ not dst, since it applies to src; for memset it applies to qiov). Note that in many places where this function is used, the previous call is qemu_iovec_reset(), which means many callers actually want copy (replacing dst content), not concat. So we may want to add a wrapper like qemu_iovec_copy() with the same arguments but which calls qemu_iovec_reset() before _concat(). This needs to be done later, so that any current out-of-tree code which uses _copy(). Signed-off-by: Michael Tokarev --- block.c | 4 +- block/qcow2.c | 4 +- block/qed.c | 6 ++-- cutils.c | 54 ++++++++++++++++++-------------------------------- hw/9pfs/virtio-9p.c | 8 +++--- qemu-common.h | 5 +-- 6 files changed, 33 insertions(+), 48 deletions(-) diff --git a/block.c b/block.c index f4320be..9246518 100644 --- a/block.c +++ b/block.c @@ -2959,13 +2959,13 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, // Add the first request to the merged one. If the requests are // overlapping, drop the last sectors of the first request. size = (reqs[i].sector - reqs[outidx].sector) << 9; - qemu_iovec_concat(qiov, reqs[outidx].qiov, size); + qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); // We should need to add any zeros between the two requests assert (reqs[i].sector <= oldreq_last); // Add the second request - qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size); + qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); reqs[outidx].nb_sectors = qiov->size >> 9; reqs[outidx].qiov = qiov; diff --git a/block/qcow2.c b/block/qcow2.c index 106f2ce..894fb4d 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -445,7 +445,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, index_in_cluster = sector_num & (s->cluster_sectors - 1); qemu_iovec_reset(&hd_qiov); - qemu_iovec_copy(&hd_qiov, qiov, bytes_done, + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_nr_sectors * 512); if (!cluster_offset) { @@ -593,7 +593,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, assert((cluster_offset & 511) == 0); qemu_iovec_reset(&hd_qiov); - qemu_iovec_copy(&hd_qiov, qiov, bytes_done, + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_nr_sectors * 512); if (s->crypt_method) { diff --git a/block/qed.c b/block/qed.c index 6f9325b..a4ef12c 100644 --- a/block/qed.c +++ b/block/qed.c @@ -1133,7 +1133,7 @@ static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) acb->cur_nclusters = qed_bytes_to_clusters(s, qed_offset_into_cluster(s, acb->cur_pos) + len); - qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); + qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); if (acb->flags & QED_AIOCB_ZERO) { /* Skip ahead if the clusters are already zero */ @@ -1179,7 +1179,7 @@ static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len) /* Calculate the I/O vector */ acb->cur_cluster = offset; - qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); + qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); /* Do the actual write */ qed_aio_write_main(acb, 0); @@ -1249,7 +1249,7 @@ static void qed_aio_read_data(void *opaque, int ret, goto err; } - qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); + qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); /* Handle zero cluster and backing file reads */ if (ret == QED_CLUSTER_ZERO) { diff --git a/cutils.c b/cutils.c index 1c93ed4..b8fc954 100644 --- a/cutils.c +++ b/cutils.c @@ -172,48 +172,34 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len) } /* - * Copies iovecs from src to the end of dst. It starts copying after skipping - * the given number of bytes in src and copies until src is completely copied - * or the total size of the copied iovec reaches size.The size of the last - * copied iovec is changed in order to fit the specified total size if it isn't - * a perfect fit already. + * Concatenates (partial) iovecs from src to the end of dst. + * It starts copying after skipping `soffset' bytes at the + * beginning of src and adds individual vectors from src to + * dst copies up to `sbytes' bytes total, or up to the end + * of src if it comes first. This way, it is okay to specify + * very large value for `sbytes' to indicate "up to the end + * of src". + * Only vector pointers are processed, not the actual data buffers. */ -void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip, - size_t size) +void qemu_iovec_concat(QEMUIOVector *dst, + QEMUIOVector *src, size_t soffset, size_t sbytes) { int i; size_t done; - void *iov_base; - uint64_t iov_len; - + struct iovec *siov = src->iov; assert(dst->nalloc != -1); - - done = 0; - for (i = 0; (i < src->niov) && (done != size); i++) { - if (skip >= src->iov[i].iov_len) { - /* Skip the whole iov */ - skip -= src->iov[i].iov_len; - continue; + assert(src->size >= soffset); + for (i = 0, done = 0; done < sbytes && i < src->niov; i++) { + if (soffset < siov[i].iov_len) { + size_t len = MIN(siov[i].iov_len - soffset, sbytes - done); + qemu_iovec_add(dst, siov[i].iov_base + soffset, len); + done += len; + soffset = 0; } else { - /* Skip only part (or nothing) of the iov */ - iov_base = (uint8_t*) src->iov[i].iov_base + skip; - iov_len = src->iov[i].iov_len - skip; - skip = 0; + soffset -= siov[i].iov_len; } - - if (done + iov_len > size) { - qemu_iovec_add(dst, iov_base, size - done); - break; - } else { - qemu_iovec_add(dst, iov_base, iov_len); - } - done += iov_len; } -} - -void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size) -{ - qemu_iovec_copy(dst, src, 0, size); + /* return done; */ } void qemu_iovec_destroy(QEMUIOVector *qiov) diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c index c633fb9..f4a7026 100644 --- a/hw/9pfs/virtio-9p.c +++ b/hw/9pfs/virtio-9p.c @@ -1648,7 +1648,7 @@ out: * with qemu_iovec_destroy(). */ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu, - uint64_t skip, size_t size, + size_t skip, size_t size, bool is_write) { QEMUIOVector elem; @@ -1665,7 +1665,7 @@ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu, qemu_iovec_init_external(&elem, iov, niov); qemu_iovec_init(qiov, niov); - qemu_iovec_copy(qiov, &elem, skip, size); + qemu_iovec_concat(qiov, &elem, skip, size); } static void v9fs_read(void *opaque) @@ -1715,7 +1715,7 @@ static void v9fs_read(void *opaque) qemu_iovec_init(&qiov, qiov_full.niov); do { qemu_iovec_reset(&qiov); - qemu_iovec_copy(&qiov, &qiov_full, count, qiov_full.size - count); + qemu_iovec_concat(&qiov, &qiov_full, count, qiov_full.size - count); if (0) { print_sg(qiov.iov, qiov.niov); } @@ -1970,7 +1970,7 @@ static void v9fs_write(void *opaque) qemu_iovec_init(&qiov, qiov_full.niov); do { qemu_iovec_reset(&qiov); - qemu_iovec_copy(&qiov, &qiov_full, total, qiov_full.size - total); + qemu_iovec_concat(&qiov, &qiov_full, total, qiov_full.size - total); if (0) { print_sg(qiov.iov, qiov.niov); } diff --git a/qemu-common.h b/qemu-common.h index 2cbb513..31b30b5 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -333,9 +333,8 @@ typedef struct QEMUIOVector { void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint); void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov); void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len); -void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip, - size_t size); -void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size); +void qemu_iovec_concat(QEMUIOVector *dst, + QEMUIOVector *src, size_t soffset, size_t sbytes); void qemu_iovec_destroy(QEMUIOVector *qiov); void qemu_iovec_reset(QEMUIOVector *qiov); void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf); -- 1.7.9.1