There are no block drivers left that implement the old .bdrv_read/write interface, so it can be removed now. This gets us rid of the corresponding emulation functions, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2782 lines
81 KiB
C
2782 lines
81 KiB
C
/*
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* Block layer I/O functions
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "trace.h"
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#include "sysemu/block-backend.h"
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#include "block/blockjob.h"
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#include "block/block_int.h"
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#include "block/throttle-groups.h"
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#include "qemu/cutils.h"
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#include "qapi/error.h"
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#include "qemu/error-report.h"
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#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
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static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
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int64_t sector_num,
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QEMUIOVector *qiov,
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int nb_sectors,
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BdrvRequestFlags flags,
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BlockCompletionFunc *cb,
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void *opaque,
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bool is_write);
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static void coroutine_fn bdrv_co_do_rw(void *opaque);
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static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
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int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
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/* throttling disk I/O limits */
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void bdrv_set_io_limits(BlockDriverState *bs,
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ThrottleConfig *cfg)
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{
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throttle_group_config(bs, cfg);
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}
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void bdrv_no_throttling_begin(BlockDriverState *bs)
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{
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if (bs->io_limits_disabled++ == 0) {
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throttle_group_restart_bs(bs);
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}
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}
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void bdrv_no_throttling_end(BlockDriverState *bs)
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{
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assert(bs->io_limits_disabled);
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--bs->io_limits_disabled;
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}
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void bdrv_io_limits_disable(BlockDriverState *bs)
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{
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assert(bs->throttle_state);
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bdrv_no_throttling_begin(bs);
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throttle_group_unregister_bs(bs);
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bdrv_no_throttling_end(bs);
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}
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/* should be called before bdrv_set_io_limits if a limit is set */
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void bdrv_io_limits_enable(BlockDriverState *bs, const char *group)
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{
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assert(!bs->throttle_state);
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throttle_group_register_bs(bs, group);
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}
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void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group)
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{
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/* this bs is not part of any group */
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if (!bs->throttle_state) {
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return;
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}
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/* this bs is a part of the same group than the one we want */
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if (!g_strcmp0(throttle_group_get_name(bs), group)) {
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return;
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}
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/* need to change the group this bs belong to */
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bdrv_io_limits_disable(bs);
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bdrv_io_limits_enable(bs, group);
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}
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void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
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{
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BlockDriver *drv = bs->drv;
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Error *local_err = NULL;
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memset(&bs->bl, 0, sizeof(bs->bl));
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if (!drv) {
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return;
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}
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/* Take some limits from the children as a default */
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if (bs->file) {
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bdrv_refresh_limits(bs->file->bs, &local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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bs->bl.opt_transfer_length = bs->file->bs->bl.opt_transfer_length;
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bs->bl.max_transfer_length = bs->file->bs->bl.max_transfer_length;
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bs->bl.min_mem_alignment = bs->file->bs->bl.min_mem_alignment;
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bs->bl.opt_mem_alignment = bs->file->bs->bl.opt_mem_alignment;
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bs->bl.max_iov = bs->file->bs->bl.max_iov;
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} else {
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bs->bl.min_mem_alignment = 512;
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bs->bl.opt_mem_alignment = getpagesize();
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/* Safe default since most protocols use readv()/writev()/etc */
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bs->bl.max_iov = IOV_MAX;
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}
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if (bs->backing) {
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bdrv_refresh_limits(bs->backing->bs, &local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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bs->bl.opt_transfer_length =
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MAX(bs->bl.opt_transfer_length,
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bs->backing->bs->bl.opt_transfer_length);
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bs->bl.max_transfer_length =
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MIN_NON_ZERO(bs->bl.max_transfer_length,
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bs->backing->bs->bl.max_transfer_length);
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bs->bl.opt_mem_alignment =
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MAX(bs->bl.opt_mem_alignment,
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bs->backing->bs->bl.opt_mem_alignment);
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bs->bl.min_mem_alignment =
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MAX(bs->bl.min_mem_alignment,
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bs->backing->bs->bl.min_mem_alignment);
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bs->bl.max_iov =
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MIN(bs->bl.max_iov,
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bs->backing->bs->bl.max_iov);
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}
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/* Then let the driver override it */
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if (drv->bdrv_refresh_limits) {
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drv->bdrv_refresh_limits(bs, errp);
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}
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}
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/**
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* The copy-on-read flag is actually a reference count so multiple users may
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* use the feature without worrying about clobbering its previous state.
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* Copy-on-read stays enabled until all users have called to disable it.
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*/
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void bdrv_enable_copy_on_read(BlockDriverState *bs)
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{
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bs->copy_on_read++;
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}
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void bdrv_disable_copy_on_read(BlockDriverState *bs)
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{
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assert(bs->copy_on_read > 0);
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bs->copy_on_read--;
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}
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/* Check if any requests are in-flight (including throttled requests) */
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bool bdrv_requests_pending(BlockDriverState *bs)
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{
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BdrvChild *child;
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if (!QLIST_EMPTY(&bs->tracked_requests)) {
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return true;
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}
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if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
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return true;
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}
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if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
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return true;
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}
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QLIST_FOREACH(child, &bs->children, next) {
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if (bdrv_requests_pending(child->bs)) {
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return true;
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}
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}
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return false;
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}
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static void bdrv_drain_recurse(BlockDriverState *bs)
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{
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BdrvChild *child;
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if (bs->drv && bs->drv->bdrv_drain) {
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bs->drv->bdrv_drain(bs);
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}
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QLIST_FOREACH(child, &bs->children, next) {
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bdrv_drain_recurse(child->bs);
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}
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}
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typedef struct {
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Coroutine *co;
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BlockDriverState *bs;
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QEMUBH *bh;
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bool done;
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} BdrvCoDrainData;
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static void bdrv_drain_poll(BlockDriverState *bs)
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{
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bool busy = true;
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while (busy) {
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/* Keep iterating */
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busy = bdrv_requests_pending(bs);
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busy |= aio_poll(bdrv_get_aio_context(bs), busy);
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}
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}
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static void bdrv_co_drain_bh_cb(void *opaque)
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{
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BdrvCoDrainData *data = opaque;
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Coroutine *co = data->co;
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qemu_bh_delete(data->bh);
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bdrv_drain_poll(data->bs);
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data->done = true;
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qemu_coroutine_enter(co, NULL);
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}
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static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
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{
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BdrvCoDrainData data;
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/* Calling bdrv_drain() from a BH ensures the current coroutine yields and
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* other coroutines run if they were queued from
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* qemu_co_queue_run_restart(). */
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assert(qemu_in_coroutine());
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data = (BdrvCoDrainData) {
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.co = qemu_coroutine_self(),
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.bs = bs,
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.done = false,
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.bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_drain_bh_cb, &data),
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};
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qemu_bh_schedule(data.bh);
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qemu_coroutine_yield();
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/* If we are resumed from some other event (such as an aio completion or a
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* timer callback), it is a bug in the caller that should be fixed. */
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assert(data.done);
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}
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/*
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* Wait for pending requests to complete on a single BlockDriverState subtree,
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* and suspend block driver's internal I/O until next request arrives.
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*
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* Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
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* AioContext.
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*
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* Only this BlockDriverState's AioContext is run, so in-flight requests must
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* not depend on events in other AioContexts. In that case, use
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* bdrv_drain_all() instead.
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*/
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void coroutine_fn bdrv_co_drain(BlockDriverState *bs)
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{
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bdrv_no_throttling_begin(bs);
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bdrv_io_unplugged_begin(bs);
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bdrv_drain_recurse(bs);
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bdrv_co_yield_to_drain(bs);
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bdrv_io_unplugged_end(bs);
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bdrv_no_throttling_end(bs);
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}
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void bdrv_drain(BlockDriverState *bs)
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{
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bdrv_no_throttling_begin(bs);
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bdrv_io_unplugged_begin(bs);
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bdrv_drain_recurse(bs);
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if (qemu_in_coroutine()) {
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bdrv_co_yield_to_drain(bs);
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} else {
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bdrv_drain_poll(bs);
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}
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bdrv_io_unplugged_end(bs);
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bdrv_no_throttling_end(bs);
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}
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/*
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* Wait for pending requests to complete across all BlockDriverStates
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*
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* This function does not flush data to disk, use bdrv_flush_all() for that
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* after calling this function.
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*/
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void bdrv_drain_all(void)
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{
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/* Always run first iteration so any pending completion BHs run */
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bool busy = true;
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BlockDriverState *bs = NULL;
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GSList *aio_ctxs = NULL, *ctx;
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while ((bs = bdrv_next(bs))) {
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AioContext *aio_context = bdrv_get_aio_context(bs);
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aio_context_acquire(aio_context);
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if (bs->job) {
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block_job_pause(bs->job);
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}
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bdrv_no_throttling_begin(bs);
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bdrv_io_unplugged_begin(bs);
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bdrv_drain_recurse(bs);
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aio_context_release(aio_context);
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if (!g_slist_find(aio_ctxs, aio_context)) {
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aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
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}
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}
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/* Note that completion of an asynchronous I/O operation can trigger any
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* number of other I/O operations on other devices---for example a
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* coroutine can submit an I/O request to another device in response to
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* request completion. Therefore we must keep looping until there was no
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* more activity rather than simply draining each device independently.
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*/
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while (busy) {
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busy = false;
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for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
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AioContext *aio_context = ctx->data;
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bs = NULL;
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aio_context_acquire(aio_context);
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while ((bs = bdrv_next(bs))) {
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if (aio_context == bdrv_get_aio_context(bs)) {
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if (bdrv_requests_pending(bs)) {
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busy = true;
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aio_poll(aio_context, busy);
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}
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}
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}
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busy |= aio_poll(aio_context, false);
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aio_context_release(aio_context);
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}
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}
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bs = NULL;
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while ((bs = bdrv_next(bs))) {
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AioContext *aio_context = bdrv_get_aio_context(bs);
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aio_context_acquire(aio_context);
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bdrv_io_unplugged_end(bs);
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bdrv_no_throttling_end(bs);
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if (bs->job) {
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block_job_resume(bs->job);
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}
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aio_context_release(aio_context);
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}
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g_slist_free(aio_ctxs);
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}
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/**
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* Remove an active request from the tracked requests list
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*
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* This function should be called when a tracked request is completing.
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*/
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static void tracked_request_end(BdrvTrackedRequest *req)
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{
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if (req->serialising) {
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req->bs->serialising_in_flight--;
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}
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QLIST_REMOVE(req, list);
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qemu_co_queue_restart_all(&req->wait_queue);
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}
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/**
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* Add an active request to the tracked requests list
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*/
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static void tracked_request_begin(BdrvTrackedRequest *req,
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BlockDriverState *bs,
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int64_t offset,
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unsigned int bytes,
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enum BdrvTrackedRequestType type)
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{
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*req = (BdrvTrackedRequest){
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.bs = bs,
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.offset = offset,
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.bytes = bytes,
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.type = type,
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.co = qemu_coroutine_self(),
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.serialising = false,
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.overlap_offset = offset,
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.overlap_bytes = bytes,
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};
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qemu_co_queue_init(&req->wait_queue);
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|
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QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
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}
|
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|
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static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
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{
|
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int64_t overlap_offset = req->offset & ~(align - 1);
|
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unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
|
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- overlap_offset;
|
|
|
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if (!req->serialising) {
|
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req->bs->serialising_in_flight++;
|
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req->serialising = true;
|
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}
|
|
|
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req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
|
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req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
|
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}
|
|
|
|
/**
|
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* Round a region to cluster boundaries
|
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*/
|
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void bdrv_round_to_clusters(BlockDriverState *bs,
|
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int64_t sector_num, int nb_sectors,
|
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int64_t *cluster_sector_num,
|
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int *cluster_nb_sectors)
|
|
{
|
|
BlockDriverInfo bdi;
|
|
|
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if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
|
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*cluster_sector_num = sector_num;
|
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*cluster_nb_sectors = nb_sectors;
|
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} else {
|
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int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
|
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*cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
|
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*cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
|
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nb_sectors, c);
|
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}
|
|
}
|
|
|
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static int bdrv_get_cluster_size(BlockDriverState *bs)
|
|
{
|
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BlockDriverInfo bdi;
|
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int ret;
|
|
|
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ret = bdrv_get_info(bs, &bdi);
|
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if (ret < 0 || bdi.cluster_size == 0) {
|
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return bs->request_alignment;
|
|
} else {
|
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return bdi.cluster_size;
|
|
}
|
|
}
|
|
|
|
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
|
|
int64_t offset, unsigned int bytes)
|
|
{
|
|
/* aaaa bbbb */
|
|
if (offset >= req->overlap_offset + req->overlap_bytes) {
|
|
return false;
|
|
}
|
|
/* bbbb aaaa */
|
|
if (req->overlap_offset >= offset + bytes) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
|
|
{
|
|
BlockDriverState *bs = self->bs;
|
|
BdrvTrackedRequest *req;
|
|
bool retry;
|
|
bool waited = false;
|
|
|
|
if (!bs->serialising_in_flight) {
|
|
return false;
|
|
}
|
|
|
|
do {
|
|
retry = false;
|
|
QLIST_FOREACH(req, &bs->tracked_requests, list) {
|
|
if (req == self || (!req->serialising && !self->serialising)) {
|
|
continue;
|
|
}
|
|
if (tracked_request_overlaps(req, self->overlap_offset,
|
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self->overlap_bytes))
|
|
{
|
|
/* Hitting this means there was a reentrant request, for
|
|
* example, a block driver issuing nested requests. This must
|
|
* never happen since it means deadlock.
|
|
*/
|
|
assert(qemu_coroutine_self() != req->co);
|
|
|
|
/* If the request is already (indirectly) waiting for us, or
|
|
* will wait for us as soon as it wakes up, then just go on
|
|
* (instead of producing a deadlock in the former case). */
|
|
if (!req->waiting_for) {
|
|
self->waiting_for = req;
|
|
qemu_co_queue_wait(&req->wait_queue);
|
|
self->waiting_for = NULL;
|
|
retry = true;
|
|
waited = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
} while (retry);
|
|
|
|
return waited;
|
|
}
|
|
|
|
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
|
|
size_t size)
|
|
{
|
|
if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
|
|
return -EIO;
|
|
}
|
|
|
|
if (!bdrv_is_inserted(bs)) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
if (offset < 0) {
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EIO;
|
|
}
|
|
|
|
return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
|
|
nb_sectors * BDRV_SECTOR_SIZE);
|
|
}
|
|
|
|
typedef struct RwCo {
|
|
BlockDriverState *bs;
|
|
int64_t offset;
|
|
QEMUIOVector *qiov;
|
|
bool is_write;
|
|
int ret;
|
|
BdrvRequestFlags flags;
|
|
} RwCo;
|
|
|
|
static void coroutine_fn bdrv_rw_co_entry(void *opaque)
|
|
{
|
|
RwCo *rwco = opaque;
|
|
|
|
if (!rwco->is_write) {
|
|
rwco->ret = bdrv_co_preadv(rwco->bs, rwco->offset,
|
|
rwco->qiov->size, rwco->qiov,
|
|
rwco->flags);
|
|
} else {
|
|
rwco->ret = bdrv_co_pwritev(rwco->bs, rwco->offset,
|
|
rwco->qiov->size, rwco->qiov,
|
|
rwco->flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Process a vectored synchronous request using coroutines
|
|
*/
|
|
static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
|
|
QEMUIOVector *qiov, bool is_write,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
Coroutine *co;
|
|
RwCo rwco = {
|
|
.bs = bs,
|
|
.offset = offset,
|
|
.qiov = qiov,
|
|
.is_write = is_write,
|
|
.ret = NOT_DONE,
|
|
.flags = flags,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_rw_co_entry(&rwco);
|
|
} else {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_rw_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
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, BdrvRequestFlags flags)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *)buf,
|
|
.iov_len = nb_sectors * BDRV_SECTOR_SIZE,
|
|
};
|
|
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
|
|
&qiov, is_write, flags);
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
|
|
}
|
|
|
|
/* Return < 0 if error. Important errors are:
|
|
-EIO generic I/O error (may happen for all errors)
|
|
-ENOMEDIUM No media inserted.
|
|
-EINVAL Invalid sector number or nb_sectors
|
|
-EACCES Trying to write a read-only device
|
|
*/
|
|
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
|
|
}
|
|
|
|
int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, BdrvRequestFlags flags)
|
|
{
|
|
return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
|
|
BDRV_REQ_ZERO_WRITE | flags);
|
|
}
|
|
|
|
/*
|
|
* 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).
|
|
*
|
|
* Returns < 0 on error, 0 on success. For error codes see bdrv_write().
|
|
*/
|
|
int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
|
|
{
|
|
int64_t target_sectors, ret, nb_sectors, sector_num = 0;
|
|
BlockDriverState *file;
|
|
int n;
|
|
|
|
target_sectors = bdrv_nb_sectors(bs);
|
|
if (target_sectors < 0) {
|
|
return target_sectors;
|
|
}
|
|
|
|
for (;;) {
|
|
nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
|
|
if (nb_sectors <= 0) {
|
|
return 0;
|
|
}
|
|
ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &file);
|
|
if (ret < 0) {
|
|
error_report("error getting block status at sector %" PRId64 ": %s",
|
|
sector_num, strerror(-ret));
|
|
return ret;
|
|
}
|
|
if (ret & BDRV_BLOCK_ZERO) {
|
|
sector_num += n;
|
|
continue;
|
|
}
|
|
ret = bdrv_write_zeroes(bs, sector_num, n, flags);
|
|
if (ret < 0) {
|
|
error_report("error writing zeroes at sector %" PRId64 ": %s",
|
|
sector_num, strerror(-ret));
|
|
return ret;
|
|
}
|
|
sector_num += n;
|
|
}
|
|
}
|
|
|
|
int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *)buf,
|
|
.iov_len = bytes,
|
|
};
|
|
int ret;
|
|
|
|
if (bytes < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return bytes;
|
|
}
|
|
|
|
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
|
|
{
|
|
int ret;
|
|
|
|
ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return qiov->size;
|
|
}
|
|
|
|
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
|
|
const void *buf, int bytes)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *) buf,
|
|
.iov_len = bytes,
|
|
};
|
|
|
|
if (bytes < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
return bdrv_pwritev(bs, offset, &qiov);
|
|
}
|
|
|
|
/*
|
|
* Writes to the file and ensures that no writes are reordered across this
|
|
* request (acts as a barrier)
|
|
*
|
|
* Returns 0 on success, -errno in error cases.
|
|
*/
|
|
int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
|
|
const void *buf, int count)
|
|
{
|
|
int ret;
|
|
|
|
ret = bdrv_pwrite(bs, offset, buf, count);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
ret = bdrv_flush(bs);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
typedef struct CoroutineIOCompletion {
|
|
Coroutine *coroutine;
|
|
int ret;
|
|
} CoroutineIOCompletion;
|
|
|
|
static void bdrv_co_io_em_complete(void *opaque, int ret)
|
|
{
|
|
CoroutineIOCompletion *co = opaque;
|
|
|
|
co->ret = ret;
|
|
qemu_coroutine_enter(co->coroutine, NULL);
|
|
}
|
|
|
|
static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
|
|
uint64_t offset, uint64_t bytes,
|
|
QEMUIOVector *qiov, int flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int64_t sector_num;
|
|
unsigned int nb_sectors;
|
|
|
|
if (drv->bdrv_co_preadv) {
|
|
return drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags);
|
|
}
|
|
|
|
sector_num = offset >> BDRV_SECTOR_BITS;
|
|
nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
|
|
|
|
if (drv->bdrv_co_readv) {
|
|
return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
|
|
} else {
|
|
BlockAIOCB *acb;
|
|
CoroutineIOCompletion co = {
|
|
.coroutine = qemu_coroutine_self(),
|
|
};
|
|
|
|
acb = bs->drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
|
|
bdrv_co_io_em_complete, &co);
|
|
if (acb == NULL) {
|
|
return -EIO;
|
|
} else {
|
|
qemu_coroutine_yield();
|
|
return co.ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
|
|
uint64_t offset, uint64_t bytes,
|
|
QEMUIOVector *qiov, int flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int64_t sector_num;
|
|
unsigned int nb_sectors;
|
|
int ret;
|
|
|
|
if (drv->bdrv_co_pwritev) {
|
|
ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, flags);
|
|
goto emulate_flags;
|
|
}
|
|
|
|
sector_num = offset >> BDRV_SECTOR_BITS;
|
|
nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
|
|
|
|
if (drv->bdrv_co_writev_flags) {
|
|
ret = drv->bdrv_co_writev_flags(bs, sector_num, nb_sectors, qiov,
|
|
flags);
|
|
} else if (drv->bdrv_co_writev) {
|
|
assert(drv->supported_write_flags == 0);
|
|
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
|
|
} else {
|
|
BlockAIOCB *acb;
|
|
CoroutineIOCompletion co = {
|
|
.coroutine = qemu_coroutine_self(),
|
|
};
|
|
|
|
acb = bs->drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
|
|
bdrv_co_io_em_complete, &co);
|
|
if (acb == NULL) {
|
|
ret = -EIO;
|
|
} else {
|
|
qemu_coroutine_yield();
|
|
ret = co.ret;
|
|
}
|
|
}
|
|
|
|
emulate_flags:
|
|
if (ret == 0 && (flags & BDRV_REQ_FUA) &&
|
|
!(drv->supported_write_flags & BDRV_REQ_FUA))
|
|
{
|
|
ret = bdrv_co_flush(bs);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
/* Perform I/O through a temporary buffer so that users who scribble over
|
|
* their read buffer while the operation is in progress do not end up
|
|
* modifying the image file. This is critical for zero-copy guest I/O
|
|
* where anything might happen inside guest memory.
|
|
*/
|
|
void *bounce_buffer;
|
|
|
|
BlockDriver *drv = bs->drv;
|
|
struct iovec iov;
|
|
QEMUIOVector bounce_qiov;
|
|
int64_t cluster_sector_num;
|
|
int cluster_nb_sectors;
|
|
size_t skip_bytes;
|
|
int ret;
|
|
|
|
/* Cover entire cluster so no additional backing file I/O is required when
|
|
* allocating cluster in the image file.
|
|
*/
|
|
bdrv_round_to_clusters(bs, sector_num, nb_sectors,
|
|
&cluster_sector_num, &cluster_nb_sectors);
|
|
|
|
trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
|
|
cluster_sector_num, cluster_nb_sectors);
|
|
|
|
iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
|
|
iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
|
|
if (bounce_buffer == NULL) {
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
|
|
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
|
|
|
|
ret = bdrv_driver_preadv(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
|
|
cluster_nb_sectors * BDRV_SECTOR_SIZE,
|
|
&bounce_qiov, 0);
|
|
if (ret < 0) {
|
|
goto err;
|
|
}
|
|
|
|
if (drv->bdrv_co_write_zeroes &&
|
|
buffer_is_zero(bounce_buffer, iov.iov_len)) {
|
|
ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
|
|
cluster_nb_sectors, 0);
|
|
} else {
|
|
/* This does not change the data on the disk, it is not necessary
|
|
* to flush even in cache=writethrough mode.
|
|
*/
|
|
ret = bdrv_driver_pwritev(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
|
|
cluster_nb_sectors * BDRV_SECTOR_SIZE,
|
|
&bounce_qiov, 0);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* It might be okay to ignore write errors for guest requests. If this
|
|
* is a deliberate copy-on-read then we don't want to ignore the error.
|
|
* Simply report it in all cases.
|
|
*/
|
|
goto err;
|
|
}
|
|
|
|
skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
|
|
qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
|
|
nb_sectors * BDRV_SECTOR_SIZE);
|
|
|
|
err:
|
|
qemu_vfree(bounce_buffer);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Forwards an already correctly aligned request to the BlockDriver. This
|
|
* handles copy on read and zeroing after EOF; any other features must be
|
|
* implemented by the caller.
|
|
*/
|
|
static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
|
|
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
|
|
int64_t align, QEMUIOVector *qiov, int flags)
|
|
{
|
|
int ret;
|
|
|
|
int64_t sector_num = offset >> BDRV_SECTOR_BITS;
|
|
unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert(!qiov || bytes == qiov->size);
|
|
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
|
|
|
|
/* Handle Copy on Read and associated serialisation */
|
|
if (flags & BDRV_REQ_COPY_ON_READ) {
|
|
/* If we touch the same cluster it counts as an overlap. This
|
|
* guarantees that allocating writes will be serialized and not race
|
|
* with each other for the same cluster. For example, in copy-on-read
|
|
* it ensures that the CoR read and write operations are atomic and
|
|
* guest writes cannot interleave between them. */
|
|
mark_request_serialising(req, bdrv_get_cluster_size(bs));
|
|
}
|
|
|
|
if (!(flags & BDRV_REQ_NO_SERIALISING)) {
|
|
wait_serialising_requests(req);
|
|
}
|
|
|
|
if (flags & BDRV_REQ_COPY_ON_READ) {
|
|
int pnum;
|
|
|
|
ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
if (!ret || pnum != nb_sectors) {
|
|
ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Forward the request to the BlockDriver */
|
|
if (!bs->zero_beyond_eof) {
|
|
ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
|
|
} else {
|
|
/* Read zeros after EOF */
|
|
int64_t total_sectors, max_nb_sectors;
|
|
|
|
total_sectors = bdrv_nb_sectors(bs);
|
|
if (total_sectors < 0) {
|
|
ret = total_sectors;
|
|
goto out;
|
|
}
|
|
|
|
max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
|
|
align >> BDRV_SECTOR_BITS);
|
|
if (nb_sectors < max_nb_sectors) {
|
|
ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
|
|
} else if (max_nb_sectors > 0) {
|
|
QEMUIOVector local_qiov;
|
|
|
|
qemu_iovec_init(&local_qiov, qiov->niov);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0,
|
|
max_nb_sectors * BDRV_SECTOR_SIZE);
|
|
|
|
ret = bdrv_driver_preadv(bs, offset,
|
|
max_nb_sectors * BDRV_SECTOR_SIZE,
|
|
&local_qiov, 0);
|
|
|
|
qemu_iovec_destroy(&local_qiov);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
/* Reading beyond end of file is supposed to produce zeroes */
|
|
if (ret == 0 && total_sectors < sector_num + nb_sectors) {
|
|
uint64_t offset = MAX(0, total_sectors - sector_num);
|
|
uint64_t bytes = (sector_num + nb_sectors - offset) *
|
|
BDRV_SECTOR_SIZE;
|
|
qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
|
|
}
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Handle a read request in coroutine context
|
|
*/
|
|
int coroutine_fn bdrv_co_preadv(BlockDriverState *bs,
|
|
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvTrackedRequest req;
|
|
|
|
/* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
|
|
uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
|
|
uint8_t *head_buf = NULL;
|
|
uint8_t *tail_buf = NULL;
|
|
QEMUIOVector local_qiov;
|
|
bool use_local_qiov = false;
|
|
int ret;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
ret = bdrv_check_byte_request(bs, offset, bytes);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* Don't do copy-on-read if we read data before write operation */
|
|
if (bs->copy_on_read && !(flags & BDRV_REQ_NO_SERIALISING)) {
|
|
flags |= BDRV_REQ_COPY_ON_READ;
|
|
}
|
|
|
|
/* throttling disk I/O */
|
|
if (bs->throttle_state) {
|
|
throttle_group_co_io_limits_intercept(bs, bytes, false);
|
|
}
|
|
|
|
/* Align read if necessary by padding qiov */
|
|
if (offset & (align - 1)) {
|
|
head_buf = qemu_blockalign(bs, align);
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 2);
|
|
qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
|
|
bytes += offset & (align - 1);
|
|
offset = offset & ~(align - 1);
|
|
}
|
|
|
|
if ((offset + bytes) & (align - 1)) {
|
|
if (!use_local_qiov) {
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 1);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
}
|
|
tail_buf = qemu_blockalign(bs, align);
|
|
qemu_iovec_add(&local_qiov, tail_buf,
|
|
align - ((offset + bytes) & (align - 1)));
|
|
|
|
bytes = ROUND_UP(bytes, align);
|
|
}
|
|
|
|
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
|
|
ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
|
|
use_local_qiov ? &local_qiov : qiov,
|
|
flags);
|
|
tracked_request_end(&req);
|
|
|
|
if (use_local_qiov) {
|
|
qemu_iovec_destroy(&local_qiov);
|
|
qemu_vfree(head_buf);
|
|
qemu_vfree(tail_buf);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return bdrv_co_preadv(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
trace_bdrv_co_readv(bs, sector_num, nb_sectors);
|
|
|
|
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
trace_bdrv_co_readv_no_serialising(bs, sector_num, nb_sectors);
|
|
|
|
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
|
|
BDRV_REQ_NO_SERIALISING);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);
|
|
|
|
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
|
|
BDRV_REQ_COPY_ON_READ);
|
|
}
|
|
|
|
#define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
|
|
|
|
static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {0};
|
|
int ret = 0;
|
|
|
|
int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes,
|
|
BDRV_REQUEST_MAX_SECTORS);
|
|
|
|
while (nb_sectors > 0 && !ret) {
|
|
int num = nb_sectors;
|
|
|
|
/* Align request. Block drivers can expect the "bulk" of the request
|
|
* to be aligned.
|
|
*/
|
|
if (bs->bl.write_zeroes_alignment
|
|
&& num > bs->bl.write_zeroes_alignment) {
|
|
if (sector_num % bs->bl.write_zeroes_alignment != 0) {
|
|
/* Make a small request up to the first aligned sector. */
|
|
num = bs->bl.write_zeroes_alignment;
|
|
num -= sector_num % bs->bl.write_zeroes_alignment;
|
|
} else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) {
|
|
/* Shorten the request to the last aligned sector. num cannot
|
|
* underflow because num > bs->bl.write_zeroes_alignment.
|
|
*/
|
|
num -= (sector_num + num) % bs->bl.write_zeroes_alignment;
|
|
}
|
|
}
|
|
|
|
/* limit request size */
|
|
if (num > max_write_zeroes) {
|
|
num = max_write_zeroes;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
num = MIN(num, max_xfer_len);
|
|
iov.iov_len = num * BDRV_SECTOR_SIZE;
|
|
if (iov.iov_base == NULL) {
|
|
iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE);
|
|
if (iov.iov_base == NULL) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
|
|
}
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
|
|
ret = bdrv_driver_pwritev(bs, sector_num * BDRV_SECTOR_SIZE,
|
|
num * BDRV_SECTOR_SIZE, &qiov, 0);
|
|
|
|
/* Keep bounce buffer around if it is big enough for all
|
|
* all future requests.
|
|
*/
|
|
if (num < max_xfer_len) {
|
|
qemu_vfree(iov.iov_base);
|
|
iov.iov_base = NULL;
|
|
}
|
|
}
|
|
|
|
sector_num += num;
|
|
nb_sectors -= num;
|
|
}
|
|
|
|
fail:
|
|
qemu_vfree(iov.iov_base);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Forwards an already correctly aligned write request to the BlockDriver.
|
|
*/
|
|
static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
|
|
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
|
|
QEMUIOVector *qiov, int flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
bool waited;
|
|
int ret;
|
|
|
|
int64_t sector_num = offset >> BDRV_SECTOR_BITS;
|
|
unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert(!qiov || bytes == qiov->size);
|
|
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
|
|
|
|
waited = wait_serialising_requests(req);
|
|
assert(!waited || !req->serialising);
|
|
assert(req->overlap_offset <= offset);
|
|
assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
|
|
|
|
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
|
|
|
|
if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
|
|
!(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
|
|
qemu_iovec_is_zero(qiov)) {
|
|
flags |= BDRV_REQ_ZERO_WRITE;
|
|
if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
|
|
flags |= BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* Do nothing, write notifier decided to fail this request */
|
|
} else if (flags & BDRV_REQ_ZERO_WRITE) {
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
|
|
ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
|
|
} else {
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV);
|
|
ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags);
|
|
}
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
|
|
|
|
bdrv_set_dirty(bs, sector_num, nb_sectors);
|
|
|
|
if (bs->wr_highest_offset < offset + bytes) {
|
|
bs->wr_highest_offset = offset + bytes;
|
|
}
|
|
|
|
if (ret >= 0) {
|
|
bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs,
|
|
int64_t offset,
|
|
unsigned int bytes,
|
|
BdrvRequestFlags flags,
|
|
BdrvTrackedRequest *req)
|
|
{
|
|
uint8_t *buf = NULL;
|
|
QEMUIOVector local_qiov;
|
|
struct iovec iov;
|
|
uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
|
|
unsigned int head_padding_bytes, tail_padding_bytes;
|
|
int ret = 0;
|
|
|
|
head_padding_bytes = offset & (align - 1);
|
|
tail_padding_bytes = align - ((offset + bytes) & (align - 1));
|
|
|
|
|
|
assert(flags & BDRV_REQ_ZERO_WRITE);
|
|
if (head_padding_bytes || tail_padding_bytes) {
|
|
buf = qemu_blockalign(bs, align);
|
|
iov = (struct iovec) {
|
|
.iov_base = buf,
|
|
.iov_len = align,
|
|
};
|
|
qemu_iovec_init_external(&local_qiov, &iov, 1);
|
|
}
|
|
if (head_padding_bytes) {
|
|
uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes);
|
|
|
|
/* RMW the unaligned part before head. */
|
|
mark_request_serialising(req, align);
|
|
wait_serialising_requests(req);
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
|
|
ret = bdrv_aligned_preadv(bs, req, offset & ~(align - 1), align,
|
|
align, &local_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
|
|
|
|
memset(buf + head_padding_bytes, 0, zero_bytes);
|
|
ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align,
|
|
&local_qiov,
|
|
flags & ~BDRV_REQ_ZERO_WRITE);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
offset += zero_bytes;
|
|
bytes -= zero_bytes;
|
|
}
|
|
|
|
assert(!bytes || (offset & (align - 1)) == 0);
|
|
if (bytes >= align) {
|
|
/* Write the aligned part in the middle. */
|
|
uint64_t aligned_bytes = bytes & ~(align - 1);
|
|
ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes,
|
|
NULL, flags);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bytes -= aligned_bytes;
|
|
offset += aligned_bytes;
|
|
}
|
|
|
|
assert(!bytes || (offset & (align - 1)) == 0);
|
|
if (bytes) {
|
|
assert(align == tail_padding_bytes + bytes);
|
|
/* RMW the unaligned part after tail. */
|
|
mark_request_serialising(req, align);
|
|
wait_serialising_requests(req);
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
|
|
ret = bdrv_aligned_preadv(bs, req, offset, align,
|
|
align, &local_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
|
|
|
|
memset(buf, 0, bytes);
|
|
ret = bdrv_aligned_pwritev(bs, req, offset, align,
|
|
&local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);
|
|
}
|
|
fail:
|
|
qemu_vfree(buf);
|
|
return ret;
|
|
|
|
}
|
|
|
|
/*
|
|
* Handle a write request in coroutine context
|
|
*/
|
|
int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
|
|
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
BdrvTrackedRequest req;
|
|
/* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
|
|
uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
|
|
uint8_t *head_buf = NULL;
|
|
uint8_t *tail_buf = NULL;
|
|
QEMUIOVector local_qiov;
|
|
bool use_local_qiov = false;
|
|
int ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (bs->read_only) {
|
|
return -EPERM;
|
|
}
|
|
assert(!(bs->open_flags & BDRV_O_INACTIVE));
|
|
|
|
ret = bdrv_check_byte_request(bs, offset, bytes);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* throttling disk I/O */
|
|
if (bs->throttle_state) {
|
|
throttle_group_co_io_limits_intercept(bs, bytes, true);
|
|
}
|
|
|
|
/*
|
|
* Align write if necessary by performing a read-modify-write cycle.
|
|
* Pad qiov with the read parts and be sure to have a tracked request not
|
|
* only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
|
|
*/
|
|
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE);
|
|
|
|
if (!qiov) {
|
|
ret = bdrv_co_do_zero_pwritev(bs, offset, bytes, flags, &req);
|
|
goto out;
|
|
}
|
|
|
|
if (offset & (align - 1)) {
|
|
QEMUIOVector head_qiov;
|
|
struct iovec head_iov;
|
|
|
|
mark_request_serialising(&req, align);
|
|
wait_serialising_requests(&req);
|
|
|
|
head_buf = qemu_blockalign(bs, align);
|
|
head_iov = (struct iovec) {
|
|
.iov_base = head_buf,
|
|
.iov_len = align,
|
|
};
|
|
qemu_iovec_init_external(&head_qiov, &head_iov, 1);
|
|
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
|
|
ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
|
|
align, &head_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
|
|
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 2);
|
|
qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
|
|
bytes += offset & (align - 1);
|
|
offset = offset & ~(align - 1);
|
|
}
|
|
|
|
if ((offset + bytes) & (align - 1)) {
|
|
QEMUIOVector tail_qiov;
|
|
struct iovec tail_iov;
|
|
size_t tail_bytes;
|
|
bool waited;
|
|
|
|
mark_request_serialising(&req, align);
|
|
waited = wait_serialising_requests(&req);
|
|
assert(!waited || !use_local_qiov);
|
|
|
|
tail_buf = qemu_blockalign(bs, align);
|
|
tail_iov = (struct iovec) {
|
|
.iov_base = tail_buf,
|
|
.iov_len = align,
|
|
};
|
|
qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
|
|
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
|
|
ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align,
|
|
align, &tail_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
|
|
|
|
if (!use_local_qiov) {
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 1);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
}
|
|
|
|
tail_bytes = (offset + bytes) & (align - 1);
|
|
qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
|
|
|
|
bytes = ROUND_UP(bytes, align);
|
|
}
|
|
|
|
ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
|
|
use_local_qiov ? &local_qiov : qiov,
|
|
flags);
|
|
|
|
fail:
|
|
|
|
if (use_local_qiov) {
|
|
qemu_iovec_destroy(&local_qiov);
|
|
}
|
|
qemu_vfree(head_buf);
|
|
qemu_vfree(tail_buf);
|
|
out:
|
|
tracked_request_end(&req);
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return bdrv_co_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
trace_bdrv_co_writev(bs, sector_num, nb_sectors);
|
|
|
|
return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
|
|
|
|
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
|
flags &= ~BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
|
|
return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
|
|
BDRV_REQ_ZERO_WRITE | flags);
|
|
}
|
|
|
|
typedef struct BdrvCoGetBlockStatusData {
|
|
BlockDriverState *bs;
|
|
BlockDriverState *base;
|
|
BlockDriverState **file;
|
|
int64_t sector_num;
|
|
int nb_sectors;
|
|
int *pnum;
|
|
int64_t ret;
|
|
bool done;
|
|
} BdrvCoGetBlockStatusData;
|
|
|
|
/*
|
|
* Returns the allocation status of the specified sectors.
|
|
* Drivers not implementing the functionality are assumed to not support
|
|
* backing files, hence all their sectors are reported as allocated.
|
|
*
|
|
* If 'sector_num' is beyond the end of the disk image the return value is 0
|
|
* and 'pnum' is set to 0.
|
|
*
|
|
* 'pnum' is set to the number of sectors (including and immediately following
|
|
* the specified sector) that are known to be in the same
|
|
* allocated/unallocated state.
|
|
*
|
|
* 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
|
|
* beyond the end of the disk image it will be clamped.
|
|
*
|
|
* If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, 'file'
|
|
* points to the BDS which the sector range is allocated in.
|
|
*/
|
|
static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
int nb_sectors, int *pnum,
|
|
BlockDriverState **file)
|
|
{
|
|
int64_t total_sectors;
|
|
int64_t n;
|
|
int64_t ret, ret2;
|
|
|
|
total_sectors = bdrv_nb_sectors(bs);
|
|
if (total_sectors < 0) {
|
|
return total_sectors;
|
|
}
|
|
|
|
if (sector_num >= total_sectors) {
|
|
*pnum = 0;
|
|
return 0;
|
|
}
|
|
|
|
n = total_sectors - sector_num;
|
|
if (n < nb_sectors) {
|
|
nb_sectors = n;
|
|
}
|
|
|
|
if (!bs->drv->bdrv_co_get_block_status) {
|
|
*pnum = nb_sectors;
|
|
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
|
|
if (bs->drv->protocol_name) {
|
|
ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
*file = NULL;
|
|
ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum,
|
|
file);
|
|
if (ret < 0) {
|
|
*pnum = 0;
|
|
return ret;
|
|
}
|
|
|
|
if (ret & BDRV_BLOCK_RAW) {
|
|
assert(ret & BDRV_BLOCK_OFFSET_VALID);
|
|
return bdrv_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS,
|
|
*pnum, pnum, file);
|
|
}
|
|
|
|
if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
|
|
ret |= BDRV_BLOCK_ALLOCATED;
|
|
} else {
|
|
if (bdrv_unallocated_blocks_are_zero(bs)) {
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
} else if (bs->backing) {
|
|
BlockDriverState *bs2 = bs->backing->bs;
|
|
int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
|
|
if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (*file && *file != bs &&
|
|
(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
|
|
(ret & BDRV_BLOCK_OFFSET_VALID)) {
|
|
BlockDriverState *file2;
|
|
int file_pnum;
|
|
|
|
ret2 = bdrv_co_get_block_status(*file, ret >> BDRV_SECTOR_BITS,
|
|
*pnum, &file_pnum, &file2);
|
|
if (ret2 >= 0) {
|
|
/* Ignore errors. This is just providing extra information, it
|
|
* is useful but not necessary.
|
|
*/
|
|
if (!file_pnum) {
|
|
/* !file_pnum indicates an offset at or beyond the EOF; it is
|
|
* perfectly valid for the format block driver to point to such
|
|
* offsets, so catch it and mark everything as zero */
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
} else {
|
|
/* Limit request to the range reported by the protocol driver */
|
|
*pnum = file_pnum;
|
|
ret |= (ret2 & BDRV_BLOCK_ZERO);
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,
|
|
BlockDriverState *base,
|
|
int64_t sector_num,
|
|
int nb_sectors,
|
|
int *pnum,
|
|
BlockDriverState **file)
|
|
{
|
|
BlockDriverState *p;
|
|
int64_t ret = 0;
|
|
|
|
assert(bs != base);
|
|
for (p = bs; p != base; p = backing_bs(p)) {
|
|
ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum, file);
|
|
if (ret < 0 || ret & BDRV_BLOCK_ALLOCATED) {
|
|
break;
|
|
}
|
|
/* [sector_num, pnum] unallocated on this layer, which could be only
|
|
* the first part of [sector_num, nb_sectors]. */
|
|
nb_sectors = MIN(nb_sectors, *pnum);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Coroutine wrapper for bdrv_get_block_status_above() */
|
|
static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque)
|
|
{
|
|
BdrvCoGetBlockStatusData *data = opaque;
|
|
|
|
data->ret = bdrv_co_get_block_status_above(data->bs, data->base,
|
|
data->sector_num,
|
|
data->nb_sectors,
|
|
data->pnum,
|
|
data->file);
|
|
data->done = true;
|
|
}
|
|
|
|
/*
|
|
* Synchronous wrapper around bdrv_co_get_block_status_above().
|
|
*
|
|
* See bdrv_co_get_block_status_above() for details.
|
|
*/
|
|
int64_t bdrv_get_block_status_above(BlockDriverState *bs,
|
|
BlockDriverState *base,
|
|
int64_t sector_num,
|
|
int nb_sectors, int *pnum,
|
|
BlockDriverState **file)
|
|
{
|
|
Coroutine *co;
|
|
BdrvCoGetBlockStatusData data = {
|
|
.bs = bs,
|
|
.base = base,
|
|
.file = file,
|
|
.sector_num = sector_num,
|
|
.nb_sectors = nb_sectors,
|
|
.pnum = pnum,
|
|
.done = false,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_get_block_status_above_co_entry(&data);
|
|
} else {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_get_block_status_above_co_entry);
|
|
qemu_coroutine_enter(co, &data);
|
|
while (!data.done) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
return data.ret;
|
|
}
|
|
|
|
int64_t bdrv_get_block_status(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
int nb_sectors, int *pnum,
|
|
BlockDriverState **file)
|
|
{
|
|
return bdrv_get_block_status_above(bs, backing_bs(bs),
|
|
sector_num, nb_sectors, pnum, file);
|
|
}
|
|
|
|
int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
BlockDriverState *file;
|
|
int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum,
|
|
&file);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
return !!(ret & BDRV_BLOCK_ALLOCATED);
|
|
}
|
|
|
|
/*
|
|
* Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
|
|
*
|
|
* Return true if the given sector is allocated in any image between
|
|
* BASE and TOP (inclusive). BASE can be NULL to check if the given
|
|
* sector is allocated in any image of the chain. Return false otherwise.
|
|
*
|
|
* 'pnum' is set to the number of sectors (including and immediately following
|
|
* the specified sector) that are known to be in the same
|
|
* allocated/unallocated state.
|
|
*
|
|
*/
|
|
int bdrv_is_allocated_above(BlockDriverState *top,
|
|
BlockDriverState *base,
|
|
int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
BlockDriverState *intermediate;
|
|
int ret, n = nb_sectors;
|
|
|
|
intermediate = top;
|
|
while (intermediate && intermediate != base) {
|
|
int pnum_inter;
|
|
ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
|
|
&pnum_inter);
|
|
if (ret < 0) {
|
|
return ret;
|
|
} else if (ret) {
|
|
*pnum = pnum_inter;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* [sector_num, nb_sectors] is unallocated on top but intermediate
|
|
* might have
|
|
*
|
|
* [sector_num+x, nr_sectors] allocated.
|
|
*/
|
|
if (n > pnum_inter &&
|
|
(intermediate == top ||
|
|
sector_num + pnum_inter < intermediate->total_sectors)) {
|
|
n = pnum_inter;
|
|
}
|
|
|
|
intermediate = backing_bs(intermediate);
|
|
}
|
|
|
|
*pnum = n;
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int ret;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!drv->bdrv_write_compressed) {
|
|
return -ENOTSUP;
|
|
}
|
|
ret = bdrv_check_request(bs, sector_num, nb_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
|
|
|
|
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
|
|
}
|
|
|
|
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
|
|
int64_t pos, int size)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *) buf,
|
|
.iov_len = size,
|
|
};
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
return bdrv_writev_vmstate(bs, &qiov, pos);
|
|
}
|
|
|
|
int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
} else if (drv->bdrv_save_vmstate) {
|
|
return drv->bdrv_save_vmstate(bs, qiov, pos);
|
|
} else if (bs->file) {
|
|
return bdrv_writev_vmstate(bs->file->bs, qiov, pos);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
|
|
int64_t pos, int size)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
if (drv->bdrv_load_vmstate)
|
|
return drv->bdrv_load_vmstate(bs, buf, pos, size);
|
|
if (bs->file)
|
|
return bdrv_load_vmstate(bs->file->bs, buf, pos, size);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* async I/Os */
|
|
|
|
BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
|
|
|
|
return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
|
|
cb, opaque, false);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
|
|
|
|
return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
|
|
cb, opaque, true);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque);
|
|
|
|
return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors,
|
|
BDRV_REQ_ZERO_WRITE | flags,
|
|
cb, opaque, true);
|
|
}
|
|
|
|
|
|
typedef struct MultiwriteCB {
|
|
int error;
|
|
int num_requests;
|
|
int num_callbacks;
|
|
struct {
|
|
BlockCompletionFunc *cb;
|
|
void *opaque;
|
|
QEMUIOVector *free_qiov;
|
|
} callbacks[];
|
|
} MultiwriteCB;
|
|
|
|
static void multiwrite_user_cb(MultiwriteCB *mcb)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < mcb->num_callbacks; i++) {
|
|
mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
|
|
if (mcb->callbacks[i].free_qiov) {
|
|
qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
|
|
}
|
|
g_free(mcb->callbacks[i].free_qiov);
|
|
}
|
|
}
|
|
|
|
static void multiwrite_cb(void *opaque, int ret)
|
|
{
|
|
MultiwriteCB *mcb = opaque;
|
|
|
|
trace_multiwrite_cb(mcb, ret);
|
|
|
|
if (ret < 0 && !mcb->error) {
|
|
mcb->error = ret;
|
|
}
|
|
|
|
mcb->num_requests--;
|
|
if (mcb->num_requests == 0) {
|
|
multiwrite_user_cb(mcb);
|
|
g_free(mcb);
|
|
}
|
|
}
|
|
|
|
static int multiwrite_req_compare(const void *a, const void *b)
|
|
{
|
|
const BlockRequest *req1 = a, *req2 = b;
|
|
|
|
/*
|
|
* Note that we can't simply subtract req2->sector from req1->sector
|
|
* here as that could overflow the return value.
|
|
*/
|
|
if (req1->sector > req2->sector) {
|
|
return 1;
|
|
} else if (req1->sector < req2->sector) {
|
|
return -1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Takes a bunch of requests and tries to merge them. Returns the number of
|
|
* requests that remain after merging.
|
|
*/
|
|
static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
|
|
int num_reqs, MultiwriteCB *mcb)
|
|
{
|
|
int i, outidx;
|
|
|
|
// Sort requests by start sector
|
|
qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
|
|
|
|
// Check if adjacent requests touch the same clusters. If so, combine them,
|
|
// filling up gaps with zero sectors.
|
|
outidx = 0;
|
|
for (i = 1; i < num_reqs; i++) {
|
|
int merge = 0;
|
|
int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
|
|
|
|
// Handle exactly sequential writes and overlapping writes.
|
|
if (reqs[i].sector <= oldreq_last) {
|
|
merge = 1;
|
|
}
|
|
|
|
if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 >
|
|
bs->bl.max_iov) {
|
|
merge = 0;
|
|
}
|
|
|
|
if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
|
|
reqs[i].nb_sectors > bs->bl.max_transfer_length) {
|
|
merge = 0;
|
|
}
|
|
|
|
if (merge) {
|
|
size_t size;
|
|
QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
|
|
qemu_iovec_init(qiov,
|
|
reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
|
|
|
|
// 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, 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, 0, reqs[i].qiov->size);
|
|
|
|
// Add tail of first request, if necessary
|
|
if (qiov->size < reqs[outidx].qiov->size) {
|
|
qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size,
|
|
reqs[outidx].qiov->size - qiov->size);
|
|
}
|
|
|
|
reqs[outidx].nb_sectors = qiov->size >> 9;
|
|
reqs[outidx].qiov = qiov;
|
|
|
|
mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
|
|
} else {
|
|
outidx++;
|
|
reqs[outidx].sector = reqs[i].sector;
|
|
reqs[outidx].nb_sectors = reqs[i].nb_sectors;
|
|
reqs[outidx].qiov = reqs[i].qiov;
|
|
}
|
|
}
|
|
|
|
if (bs->blk) {
|
|
block_acct_merge_done(blk_get_stats(bs->blk), BLOCK_ACCT_WRITE,
|
|
num_reqs - outidx - 1);
|
|
}
|
|
|
|
return outidx + 1;
|
|
}
|
|
|
|
/*
|
|
* Submit multiple AIO write requests at once.
|
|
*
|
|
* On success, the function returns 0 and all requests in the reqs array have
|
|
* been submitted. In error case this function returns -1, and any of the
|
|
* requests may or may not be submitted yet. In particular, this means that the
|
|
* callback will be called for some of the requests, for others it won't. The
|
|
* caller must check the error field of the BlockRequest to wait for the right
|
|
* callbacks (if error != 0, no callback will be called).
|
|
*
|
|
* The implementation may modify the contents of the reqs array, e.g. to merge
|
|
* requests. However, the fields opaque and error are left unmodified as they
|
|
* are used to signal failure for a single request to the caller.
|
|
*/
|
|
int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
|
|
{
|
|
MultiwriteCB *mcb;
|
|
int i;
|
|
|
|
/* don't submit writes if we don't have a medium */
|
|
if (bs->drv == NULL) {
|
|
for (i = 0; i < num_reqs; i++) {
|
|
reqs[i].error = -ENOMEDIUM;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
if (num_reqs == 0) {
|
|
return 0;
|
|
}
|
|
|
|
// Create MultiwriteCB structure
|
|
mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
|
|
mcb->num_requests = 0;
|
|
mcb->num_callbacks = num_reqs;
|
|
|
|
for (i = 0; i < num_reqs; i++) {
|
|
mcb->callbacks[i].cb = reqs[i].cb;
|
|
mcb->callbacks[i].opaque = reqs[i].opaque;
|
|
}
|
|
|
|
// Check for mergable requests
|
|
num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
|
|
|
|
trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
|
|
|
|
/* Run the aio requests. */
|
|
mcb->num_requests = num_reqs;
|
|
for (i = 0; i < num_reqs; i++) {
|
|
bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov,
|
|
reqs[i].nb_sectors, reqs[i].flags,
|
|
multiwrite_cb, mcb,
|
|
true);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bdrv_aio_cancel(BlockAIOCB *acb)
|
|
{
|
|
qemu_aio_ref(acb);
|
|
bdrv_aio_cancel_async(acb);
|
|
while (acb->refcnt > 1) {
|
|
if (acb->aiocb_info->get_aio_context) {
|
|
aio_poll(acb->aiocb_info->get_aio_context(acb), true);
|
|
} else if (acb->bs) {
|
|
aio_poll(bdrv_get_aio_context(acb->bs), true);
|
|
} else {
|
|
abort();
|
|
}
|
|
}
|
|
qemu_aio_unref(acb);
|
|
}
|
|
|
|
/* Async version of aio cancel. The caller is not blocked if the acb implements
|
|
* cancel_async, otherwise we do nothing and let the request normally complete.
|
|
* In either case the completion callback must be called. */
|
|
void bdrv_aio_cancel_async(BlockAIOCB *acb)
|
|
{
|
|
if (acb->aiocb_info->cancel_async) {
|
|
acb->aiocb_info->cancel_async(acb);
|
|
}
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* async block device emulation */
|
|
|
|
typedef struct BlockAIOCBCoroutine {
|
|
BlockAIOCB common;
|
|
BlockRequest req;
|
|
bool is_write;
|
|
bool need_bh;
|
|
bool *done;
|
|
QEMUBH* bh;
|
|
} BlockAIOCBCoroutine;
|
|
|
|
static const AIOCBInfo bdrv_em_co_aiocb_info = {
|
|
.aiocb_size = sizeof(BlockAIOCBCoroutine),
|
|
};
|
|
|
|
static void bdrv_co_complete(BlockAIOCBCoroutine *acb)
|
|
{
|
|
if (!acb->need_bh) {
|
|
acb->common.cb(acb->common.opaque, acb->req.error);
|
|
qemu_aio_unref(acb);
|
|
}
|
|
}
|
|
|
|
static void bdrv_co_em_bh(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
|
|
assert(!acb->need_bh);
|
|
qemu_bh_delete(acb->bh);
|
|
bdrv_co_complete(acb);
|
|
}
|
|
|
|
static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb)
|
|
{
|
|
acb->need_bh = false;
|
|
if (acb->req.error != -EINPROGRESS) {
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
|
|
qemu_bh_schedule(acb->bh);
|
|
}
|
|
}
|
|
|
|
/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
|
|
static void coroutine_fn bdrv_co_do_rw(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
if (!acb->is_write) {
|
|
acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
|
|
acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
|
|
} else {
|
|
acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
|
|
acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
|
|
}
|
|
|
|
bdrv_co_complete(acb);
|
|
}
|
|
|
|
static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov,
|
|
int nb_sectors,
|
|
BdrvRequestFlags flags,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque,
|
|
bool is_write)
|
|
{
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *acb;
|
|
|
|
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
|
|
acb->need_bh = true;
|
|
acb->req.error = -EINPROGRESS;
|
|
acb->req.sector = sector_num;
|
|
acb->req.nb_sectors = nb_sectors;
|
|
acb->req.qiov = qiov;
|
|
acb->req.flags = flags;
|
|
acb->is_write = is_write;
|
|
|
|
co = qemu_coroutine_create(bdrv_co_do_rw);
|
|
qemu_coroutine_enter(co, acb);
|
|
|
|
bdrv_co_maybe_schedule_bh(acb);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
acb->req.error = bdrv_co_flush(bs);
|
|
bdrv_co_complete(acb);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_flush(bs, opaque);
|
|
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *acb;
|
|
|
|
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
|
|
acb->need_bh = true;
|
|
acb->req.error = -EINPROGRESS;
|
|
|
|
co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
|
|
qemu_coroutine_enter(co, acb);
|
|
|
|
bdrv_co_maybe_schedule_bh(acb);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
|
|
bdrv_co_complete(acb);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *acb;
|
|
|
|
trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
|
|
|
|
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
|
|
acb->need_bh = true;
|
|
acb->req.error = -EINPROGRESS;
|
|
acb->req.sector = sector_num;
|
|
acb->req.nb_sectors = nb_sectors;
|
|
co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
|
|
qemu_coroutine_enter(co, acb);
|
|
|
|
bdrv_co_maybe_schedule_bh(acb);
|
|
return &acb->common;
|
|
}
|
|
|
|
void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
BlockAIOCB *acb;
|
|
|
|
acb = g_malloc(aiocb_info->aiocb_size);
|
|
acb->aiocb_info = aiocb_info;
|
|
acb->bs = bs;
|
|
acb->cb = cb;
|
|
acb->opaque = opaque;
|
|
acb->refcnt = 1;
|
|
return acb;
|
|
}
|
|
|
|
void qemu_aio_ref(void *p)
|
|
{
|
|
BlockAIOCB *acb = p;
|
|
acb->refcnt++;
|
|
}
|
|
|
|
void qemu_aio_unref(void *p)
|
|
{
|
|
BlockAIOCB *acb = p;
|
|
assert(acb->refcnt > 0);
|
|
if (--acb->refcnt == 0) {
|
|
g_free(acb);
|
|
}
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* Coroutine block device emulation */
|
|
|
|
static void coroutine_fn bdrv_flush_co_entry(void *opaque)
|
|
{
|
|
RwCo *rwco = opaque;
|
|
|
|
rwco->ret = bdrv_co_flush(rwco->bs);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
|
|
{
|
|
int ret;
|
|
BdrvTrackedRequest req;
|
|
|
|
if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) ||
|
|
bdrv_is_sg(bs)) {
|
|
return 0;
|
|
}
|
|
|
|
tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH);
|
|
|
|
/* Write back all layers by calling one driver function */
|
|
if (bs->drv->bdrv_co_flush) {
|
|
ret = bs->drv->bdrv_co_flush(bs);
|
|
goto out;
|
|
}
|
|
|
|
/* Write back cached data to the OS even with cache=unsafe */
|
|
BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
|
|
if (bs->drv->bdrv_co_flush_to_os) {
|
|
ret = bs->drv->bdrv_co_flush_to_os(bs);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* But don't actually force it to the disk with cache=unsafe */
|
|
if (bs->open_flags & BDRV_O_NO_FLUSH) {
|
|
goto flush_parent;
|
|
}
|
|
|
|
BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
|
|
if (bs->drv->bdrv_co_flush_to_disk) {
|
|
ret = bs->drv->bdrv_co_flush_to_disk(bs);
|
|
} else if (bs->drv->bdrv_aio_flush) {
|
|
BlockAIOCB *acb;
|
|
CoroutineIOCompletion co = {
|
|
.coroutine = qemu_coroutine_self(),
|
|
};
|
|
|
|
acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
|
|
if (acb == NULL) {
|
|
ret = -EIO;
|
|
} else {
|
|
qemu_coroutine_yield();
|
|
ret = co.ret;
|
|
}
|
|
} else {
|
|
/*
|
|
* Some block drivers always operate in either writethrough or unsafe
|
|
* mode and don't support bdrv_flush therefore. Usually qemu doesn't
|
|
* know how the server works (because the behaviour is hardcoded or
|
|
* depends on server-side configuration), so we can't ensure that
|
|
* everything is safe on disk. Returning an error doesn't work because
|
|
* that would break guests even if the server operates in writethrough
|
|
* mode.
|
|
*
|
|
* Let's hope the user knows what he's doing.
|
|
*/
|
|
ret = 0;
|
|
}
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
/* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
|
|
* in the case of cache=unsafe, so there are no useless flushes.
|
|
*/
|
|
flush_parent:
|
|
ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0;
|
|
out:
|
|
tracked_request_end(&req);
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_flush(BlockDriverState *bs)
|
|
{
|
|
Coroutine *co;
|
|
RwCo rwco = {
|
|
.bs = bs,
|
|
.ret = NOT_DONE,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_flush_co_entry(&rwco);
|
|
} else {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_flush_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
|
|
return rwco.ret;
|
|
}
|
|
|
|
typedef struct DiscardCo {
|
|
BlockDriverState *bs;
|
|
int64_t sector_num;
|
|
int nb_sectors;
|
|
int ret;
|
|
} DiscardCo;
|
|
static void coroutine_fn bdrv_discard_co_entry(void *opaque)
|
|
{
|
|
DiscardCo *rwco = opaque;
|
|
|
|
rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors)
|
|
{
|
|
BdrvTrackedRequest req;
|
|
int max_discard, ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
ret = bdrv_check_request(bs, sector_num, nb_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
} else if (bs->read_only) {
|
|
return -EPERM;
|
|
}
|
|
assert(!(bs->open_flags & BDRV_O_INACTIVE));
|
|
|
|
/* Do nothing if disabled. */
|
|
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
|
return 0;
|
|
}
|
|
|
|
if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
|
|
return 0;
|
|
}
|
|
|
|
tracked_request_begin(&req, bs, sector_num, nb_sectors,
|
|
BDRV_TRACKED_DISCARD);
|
|
bdrv_set_dirty(bs, sector_num, nb_sectors);
|
|
|
|
max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
|
|
while (nb_sectors > 0) {
|
|
int ret;
|
|
int num = nb_sectors;
|
|
|
|
/* align request */
|
|
if (bs->bl.discard_alignment &&
|
|
num >= bs->bl.discard_alignment &&
|
|
sector_num % bs->bl.discard_alignment) {
|
|
if (num > bs->bl.discard_alignment) {
|
|
num = bs->bl.discard_alignment;
|
|
}
|
|
num -= sector_num % bs->bl.discard_alignment;
|
|
}
|
|
|
|
/* limit request size */
|
|
if (num > max_discard) {
|
|
num = max_discard;
|
|
}
|
|
|
|
if (bs->drv->bdrv_co_discard) {
|
|
ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
|
|
} else {
|
|
BlockAIOCB *acb;
|
|
CoroutineIOCompletion co = {
|
|
.coroutine = qemu_coroutine_self(),
|
|
};
|
|
|
|
acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
|
|
bdrv_co_io_em_complete, &co);
|
|
if (acb == NULL) {
|
|
ret = -EIO;
|
|
goto out;
|
|
} else {
|
|
qemu_coroutine_yield();
|
|
ret = co.ret;
|
|
}
|
|
}
|
|
if (ret && ret != -ENOTSUP) {
|
|
goto out;
|
|
}
|
|
|
|
sector_num += num;
|
|
nb_sectors -= num;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
tracked_request_end(&req);
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
|
|
{
|
|
Coroutine *co;
|
|
DiscardCo rwco = {
|
|
.bs = bs,
|
|
.sector_num = sector_num,
|
|
.nb_sectors = nb_sectors,
|
|
.ret = NOT_DONE,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_discard_co_entry(&rwco);
|
|
} else {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_discard_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
|
|
return rwco.ret;
|
|
}
|
|
|
|
typedef struct {
|
|
CoroutineIOCompletion *co;
|
|
QEMUBH *bh;
|
|
} BdrvIoctlCompletionData;
|
|
|
|
static void bdrv_ioctl_bh_cb(void *opaque)
|
|
{
|
|
BdrvIoctlCompletionData *data = opaque;
|
|
|
|
bdrv_co_io_em_complete(data->co, -ENOTSUP);
|
|
qemu_bh_delete(data->bh);
|
|
}
|
|
|
|
static int bdrv_co_do_ioctl(BlockDriverState *bs, int req, void *buf)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvTrackedRequest tracked_req;
|
|
CoroutineIOCompletion co = {
|
|
.coroutine = qemu_coroutine_self(),
|
|
};
|
|
BlockAIOCB *acb;
|
|
|
|
tracked_request_begin(&tracked_req, bs, 0, 0, BDRV_TRACKED_IOCTL);
|
|
if (!drv || !drv->bdrv_aio_ioctl) {
|
|
co.ret = -ENOTSUP;
|
|
goto out;
|
|
}
|
|
|
|
acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co);
|
|
if (!acb) {
|
|
BdrvIoctlCompletionData *data = g_new(BdrvIoctlCompletionData, 1);
|
|
data->bh = aio_bh_new(bdrv_get_aio_context(bs),
|
|
bdrv_ioctl_bh_cb, data);
|
|
data->co = &co;
|
|
qemu_bh_schedule(data->bh);
|
|
}
|
|
qemu_coroutine_yield();
|
|
out:
|
|
tracked_request_end(&tracked_req);
|
|
return co.ret;
|
|
}
|
|
|
|
typedef struct {
|
|
BlockDriverState *bs;
|
|
int req;
|
|
void *buf;
|
|
int ret;
|
|
} BdrvIoctlCoData;
|
|
|
|
static void coroutine_fn bdrv_co_ioctl_entry(void *opaque)
|
|
{
|
|
BdrvIoctlCoData *data = opaque;
|
|
data->ret = bdrv_co_do_ioctl(data->bs, data->req, data->buf);
|
|
}
|
|
|
|
/* needed for generic scsi interface */
|
|
int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
|
|
{
|
|
BdrvIoctlCoData data = {
|
|
.bs = bs,
|
|
.req = req,
|
|
.buf = buf,
|
|
.ret = -EINPROGRESS,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_co_ioctl_entry(&data);
|
|
} else {
|
|
Coroutine *co = qemu_coroutine_create(bdrv_co_ioctl_entry);
|
|
|
|
qemu_coroutine_enter(co, &data);
|
|
while (data.ret == -EINPROGRESS) {
|
|
aio_poll(bdrv_get_aio_context(bs), true);
|
|
}
|
|
}
|
|
return data.ret;
|
|
}
|
|
|
|
static void coroutine_fn bdrv_co_aio_ioctl_entry(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
acb->req.error = bdrv_co_do_ioctl(acb->common.bs,
|
|
acb->req.req, acb->req.buf);
|
|
bdrv_co_complete(acb);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
|
|
unsigned long int req, void *buf,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = qemu_aio_get(&bdrv_em_co_aiocb_info,
|
|
bs, cb, opaque);
|
|
Coroutine *co;
|
|
|
|
acb->need_bh = true;
|
|
acb->req.error = -EINPROGRESS;
|
|
acb->req.req = req;
|
|
acb->req.buf = buf;
|
|
co = qemu_coroutine_create(bdrv_co_aio_ioctl_entry);
|
|
qemu_coroutine_enter(co, acb);
|
|
|
|
bdrv_co_maybe_schedule_bh(acb);
|
|
return &acb->common;
|
|
}
|
|
|
|
void *qemu_blockalign(BlockDriverState *bs, size_t size)
|
|
{
|
|
return qemu_memalign(bdrv_opt_mem_align(bs), size);
|
|
}
|
|
|
|
void *qemu_blockalign0(BlockDriverState *bs, size_t size)
|
|
{
|
|
return memset(qemu_blockalign(bs, size), 0, size);
|
|
}
|
|
|
|
void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
|
|
{
|
|
size_t align = bdrv_opt_mem_align(bs);
|
|
|
|
/* Ensure that NULL is never returned on success */
|
|
assert(align > 0);
|
|
if (size == 0) {
|
|
size = align;
|
|
}
|
|
|
|
return qemu_try_memalign(align, size);
|
|
}
|
|
|
|
void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
|
|
{
|
|
void *mem = qemu_try_blockalign(bs, size);
|
|
|
|
if (mem) {
|
|
memset(mem, 0, size);
|
|
}
|
|
|
|
return mem;
|
|
}
|
|
|
|
/*
|
|
* Check if all memory in this vector is sector aligned.
|
|
*/
|
|
bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
|
|
{
|
|
int i;
|
|
size_t alignment = bdrv_min_mem_align(bs);
|
|
|
|
for (i = 0; i < qiov->niov; i++) {
|
|
if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
|
|
return false;
|
|
}
|
|
if (qiov->iov[i].iov_len % alignment) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void bdrv_add_before_write_notifier(BlockDriverState *bs,
|
|
NotifierWithReturn *notifier)
|
|
{
|
|
notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
|
|
}
|
|
|
|
void bdrv_io_plug(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_io_plug(child->bs);
|
|
}
|
|
|
|
if (bs->io_plugged++ == 0 && bs->io_plug_disabled == 0) {
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_plug) {
|
|
drv->bdrv_io_plug(bs);
|
|
}
|
|
}
|
|
}
|
|
|
|
void bdrv_io_unplug(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
|
|
assert(bs->io_plugged);
|
|
if (--bs->io_plugged == 0 && bs->io_plug_disabled == 0) {
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_unplug) {
|
|
drv->bdrv_io_unplug(bs);
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_io_unplug(child->bs);
|
|
}
|
|
}
|
|
|
|
void bdrv_io_unplugged_begin(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
|
|
if (bs->io_plug_disabled++ == 0 && bs->io_plugged > 0) {
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_unplug) {
|
|
drv->bdrv_io_unplug(bs);
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_io_unplugged_begin(child->bs);
|
|
}
|
|
}
|
|
|
|
void bdrv_io_unplugged_end(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
|
|
assert(bs->io_plug_disabled);
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_io_unplugged_end(child->bs);
|
|
}
|
|
|
|
if (--bs->io_plug_disabled == 0 && bs->io_plugged > 0) {
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_plug) {
|
|
drv->bdrv_io_plug(bs);
|
|
}
|
|
}
|
|
}
|
|
|
|
void bdrv_drained_begin(BlockDriverState *bs)
|
|
{
|
|
if (!bs->quiesce_counter++) {
|
|
aio_disable_external(bdrv_get_aio_context(bs));
|
|
}
|
|
bdrv_drain(bs);
|
|
}
|
|
|
|
void bdrv_drained_end(BlockDriverState *bs)
|
|
{
|
|
assert(bs->quiesce_counter > 0);
|
|
if (--bs->quiesce_counter > 0) {
|
|
return;
|
|
}
|
|
aio_enable_external(bdrv_get_aio_context(bs));
|
|
}
|