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author | Kevin Wolf <kwolf@redhat.com> | 2013-04-05 21:27:55 +0200 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2013-04-15 08:26:18 +0200 |
commit | 8d3b1a2d0b34a95800c482e1414c63f469ac4973 (patch) | |
tree | 89f06faf7d2261daa5c3039413a1ccc06bc3f22d /block.c | |
parent | 05fcc84888cfabec2267851415b66395a73a0f5f (diff) | |
download | hqemu-8d3b1a2d0b34a95800c482e1414c63f469ac4973.zip hqemu-8d3b1a2d0b34a95800c482e1414c63f469ac4973.tar.gz |
block: Introduce bdrv_pwritev() for qcow2_save_vmstate
Directly pass the QEMUIOVector on instead of linearising it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 80 |
1 files changed, 58 insertions, 22 deletions
@@ -2131,27 +2131,21 @@ static void coroutine_fn bdrv_rw_co_entry(void *opaque) } /* - * Process a synchronous request using coroutines + * Process a vectored synchronous request using coroutines */ -static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, - int nb_sectors, bool is_write) +static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, bool is_write) { - QEMUIOVector qiov; - struct iovec iov = { - .iov_base = (void *)buf, - .iov_len = nb_sectors * BDRV_SECTOR_SIZE, - }; Coroutine *co; RwCo rwco = { .bs = bs, .sector_num = sector_num, - .nb_sectors = nb_sectors, - .qiov = &qiov, + .nb_sectors = qiov->size >> BDRV_SECTOR_BITS, + .qiov = qiov, .is_write = is_write, .ret = NOT_DONE, }; - - qemu_iovec_init_external(&qiov, &iov, 1); + assert((qiov->size & (BDRV_SECTOR_SIZE - 1)) == 0); /** * In sync call context, when the vcpu is blocked, this throttling timer @@ -2177,6 +2171,22 @@ static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, return rwco.ret; } +/* + * Process a synchronous request using coroutines + */ +static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, + int nb_sectors, bool is_write) +{ + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = (void *)buf, + .iov_len = nb_sectors * BDRV_SECTOR_SIZE, + }; + + qemu_iovec_init_external(&qiov, &iov, 1); + return bdrv_rwv_co(bs, sector_num, &qiov, is_write); +} + /* return < 0 if error. See bdrv_write() for the return codes */ int bdrv_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) @@ -2210,6 +2220,11 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num, return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true); } +int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov) +{ + return bdrv_rwv_co(bs, sector_num, qiov, true); +} + int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int count1) { @@ -2255,15 +2270,15 @@ int bdrv_pread(BlockDriverState *bs, int64_t offset, return count1; } -int bdrv_pwrite(BlockDriverState *bs, int64_t offset, - const void *buf, int count1) +int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) { uint8_t tmp_buf[BDRV_SECTOR_SIZE]; int len, nb_sectors, count; int64_t sector_num; int ret; - count = count1; + count = qiov->size; + /* first write to align to sector start */ len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); if (len > count) @@ -2272,24 +2287,32 @@ int bdrv_pwrite(BlockDriverState *bs, int64_t offset, if (len > 0) { if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) return ret; - memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len); + qemu_iovec_to_buf(qiov, 0, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), + len); if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) return ret; count -= len; if (count == 0) - return count1; + return qiov->size; sector_num++; - buf += len; } /* write the sectors "in place" */ nb_sectors = count >> BDRV_SECTOR_BITS; if (nb_sectors > 0) { - if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0) + QEMUIOVector qiov_inplace; + + qemu_iovec_init(&qiov_inplace, qiov->niov); + qemu_iovec_concat(&qiov_inplace, qiov, len, + nb_sectors << BDRV_SECTOR_BITS); + ret = bdrv_writev(bs, sector_num, &qiov_inplace); + qemu_iovec_destroy(&qiov_inplace); + if (ret < 0) { return ret; + } + sector_num += nb_sectors; len = nb_sectors << BDRV_SECTOR_BITS; - buf += len; count -= len; } @@ -2297,11 +2320,24 @@ int bdrv_pwrite(BlockDriverState *bs, int64_t offset, if (count > 0) { if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) return ret; - memcpy(tmp_buf, buf, count); + qemu_iovec_to_buf(qiov, qiov->size - count, tmp_buf, count); if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) return ret; } - return count1; + return qiov->size; +} + +int bdrv_pwrite(BlockDriverState *bs, int64_t offset, + const void *buf, int count1) +{ + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = (void *) buf, + .iov_len = count1, + }; + + qemu_iovec_init_external(&qiov, &iov, 1); + return bdrv_pwritev(bs, offset, &qiov); } /* |