From patchwork Sun Mar 11 01:49:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 145932 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 50293B6FA5 for ; Sun, 11 Mar 2012 12:51:43 +1100 (EST) Received: from localhost ([::1]:58897 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S6Xwh-0008Kq-BS for incoming@patchwork.ozlabs.org; Sat, 10 Mar 2012 20:51:39 -0500 Received: from eggs.gnu.org ([208.118.235.92]:53851) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S6Xw9-00072F-HJ for qemu-devel@nongnu.org; Sat, 10 Mar 2012 20:51:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S6Xw2-0002zW-J9 for qemu-devel@nongnu.org; Sat, 10 Mar 2012 20:51:04 -0500 Received: from isrv.corpit.ru ([86.62.121.231]:58265) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S6Xw2-0002zF-7O for qemu-devel@nongnu.org; Sat, 10 Mar 2012 20:50:58 -0500 Received: from gandalf.tls.msk.ru (mjt.vpn.tls.msk.ru [192.168.177.99]) by isrv.corpit.ru (Postfix) with ESMTP id 9A085A0755; Sun, 11 Mar 2012 05:50:53 +0400 (MSK) Received: by gandalf.tls.msk.ru (Postfix, from userid 1000) id 7A67265DF; Sun, 11 Mar 2012 05:49:37 +0400 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Date: Sun, 11 Mar 2012 05:49:20 +0400 Message-Id: <1331430564-32745-4-git-send-email-mjt@msgid.tls.msk.ru> X-Mailer: git-send-email 1.7.9.1 In-Reply-To: <1331430564-32745-1-git-send-email-mjt@msgid.tls.msk.ru> References: <1331430564-32745-1-git-send-email-mjt@msgid.tls.msk.ru> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 86.62.121.231 Cc: Michael Tokarev Subject: [Qemu-devel] [PATCHv2 3/7] consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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. Semantic change in the meaning of `count' (now renamed to `sbytes') argument. Initial comment said that src is copied to dst until _total_ size is less than specified, so it might be interpreted as maximum size of the _dst_ vector. Actual meaning of if was that total amount of skipped and copied bytes should not exceed `count'. Make it just the amount of bytes to _copy_, without counting skipped bytes. This makes it consistent with other iovec functions, and also matches actual _usage_ of this function. 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 paramere to allow resetting dst in one go. --- block.c | 4 +- block/qcow2.c | 6 ++-- block/qed.c | 6 ++-- cutils.c | 56 +++++++++++++++++++------------------------------- hw/9pfs/virtio-9p.c | 8 +++--- qemu-common.h | 5 +-- 6 files changed, 35 insertions(+), 50 deletions(-) diff --git a/block.c b/block.c index cbbedfa..3baa182 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 668e2e2..1723275 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) { @@ -514,7 +514,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, qcow2_encrypt_sectors(s, sector_num, cluster_data, cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key); 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); qemu_iovec_from_buffer(&hd_qiov, 0, cluster_data, 512 * cur_nr_sectors); @@ -596,7 +596,7 @@ 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 5353f89..04e51f7 100644 --- a/cutils.c +++ b/cutils.c @@ -171,48 +171,34 @@ 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 copies `sbytes' bytes from that point. + * 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. */ -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); + assert(src->size >= soffset); + assert(src->size - soffset >= sbytes); - 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; - } 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; - } - - 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; + /* first skip initial full-sized source elements */ + for(i = 0; soffset >= siov[i].iov_len; ++i) { + soffset -= siov[i].iov_len; + } + /* skip/copy partial element and copy the rest */ + while(sbytes) { + size_t n = MIN(sbytes, siov[i].iov_len - soffset); + qemu_iovec_add(dst, (char*)siov[i].iov_base + soffset, n); + sbytes -= n; + ++i; + soffset = 0; } -} - -void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size) -{ - qemu_iovec_copy(dst, src, 0, size); } 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 249f70d..e8d1429 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);