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authorPaolo Bonzini <pbonzini@redhat.com>2012-10-26 11:27:45 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2012-10-31 10:38:13 +0100
commit10fb6e06825743bd517d4b5bb0e7b9e05e0fe92c (patch)
tree458b6b9166c7abc785b2049c8d148a8d433a2fa2 /linux-aio.c
parentfc4edb84bfc49e4ed6c1a54c8ac037e9a7479fc8 (diff)
raw-posix: move linux-aio.c to block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'linux-aio.c')
-rw-r--r--linux-aio.c216
1 files changed, 0 insertions, 216 deletions
diff --git a/linux-aio.c b/linux-aio.c
deleted file mode 100644
index 6ca984dbe8..0000000000
--- a/linux-aio.c
+++ /dev/null
@@ -1,216 +0,0 @@
-/*
- * Linux native AIO support.
- *
- * Copyright (C) 2009 IBM, Corp.
- * Copyright (C) 2009 Red Hat, Inc.
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- */
-#include "qemu-common.h"
-#include "qemu-aio.h"
-#include "qemu-queue.h"
-#include "block/raw-aio.h"
-#include "event_notifier.h"
-
-#include <libaio.h>
-
-/*
- * Queue size (per-device).
- *
- * XXX: eventually we need to communicate this to the guest and/or make it
- * tunable by the guest. If we get more outstanding requests at a time
- * than this we will get EAGAIN from io_submit which is communicated to
- * the guest as an I/O error.
- */
-#define MAX_EVENTS 128
-
-struct qemu_laiocb {
- BlockDriverAIOCB common;
- struct qemu_laio_state *ctx;
- struct iocb iocb;
- ssize_t ret;
- size_t nbytes;
- QEMUIOVector *qiov;
- bool is_read;
- QLIST_ENTRY(qemu_laiocb) node;
-};
-
-struct qemu_laio_state {
- io_context_t ctx;
- EventNotifier e;
- int count;
-};
-
-static inline ssize_t io_event_ret(struct io_event *ev)
-{
- return (ssize_t)(((uint64_t)ev->res2 << 32) | ev->res);
-}
-
-/*
- * Completes an AIO request (calls the callback and frees the ACB).
- */
-static void qemu_laio_process_completion(struct qemu_laio_state *s,
- struct qemu_laiocb *laiocb)
-{
- int ret;
-
- s->count--;
-
- ret = laiocb->ret;
- if (ret != -ECANCELED) {
- if (ret == laiocb->nbytes) {
- ret = 0;
- } else if (ret >= 0) {
- /* Short reads mean EOF, pad with zeros. */
- if (laiocb->is_read) {
- qemu_iovec_memset(laiocb->qiov, ret, 0,
- laiocb->qiov->size - ret);
- } else {
- ret = -EINVAL;
- }
- }
-
- laiocb->common.cb(laiocb->common.opaque, ret);
- }
-
- qemu_aio_release(laiocb);
-}
-
-static void qemu_laio_completion_cb(EventNotifier *e)
-{
- struct qemu_laio_state *s = container_of(e, struct qemu_laio_state, e);
-
- while (event_notifier_test_and_clear(&s->e)) {
- struct io_event events[MAX_EVENTS];
- struct timespec ts = { 0 };
- int nevents, i;
-
- do {
- nevents = io_getevents(s->ctx, MAX_EVENTS, MAX_EVENTS, events, &ts);
- } while (nevents == -EINTR);
-
- for (i = 0; i < nevents; i++) {
- struct iocb *iocb = events[i].obj;
- struct qemu_laiocb *laiocb =
- container_of(iocb, struct qemu_laiocb, iocb);
-
- laiocb->ret = io_event_ret(&events[i]);
- qemu_laio_process_completion(s, laiocb);
- }
- }
-}
-
-static int qemu_laio_flush_cb(EventNotifier *e)
-{
- struct qemu_laio_state *s = container_of(e, struct qemu_laio_state, e);
-
- return (s->count > 0) ? 1 : 0;
-}
-
-static void laio_cancel(BlockDriverAIOCB *blockacb)
-{
- struct qemu_laiocb *laiocb = (struct qemu_laiocb *)blockacb;
- struct io_event event;
- int ret;
-
- if (laiocb->ret != -EINPROGRESS)
- return;
-
- /*
- * Note that as of Linux 2.6.31 neither the block device code nor any
- * filesystem implements cancellation of AIO request.
- * Thus the polling loop below is the normal code path.
- */
- ret = io_cancel(laiocb->ctx->ctx, &laiocb->iocb, &event);
- if (ret == 0) {
- laiocb->ret = -ECANCELED;
- return;
- }
-
- /*
- * We have to wait for the iocb to finish.
- *
- * The only way to get the iocb status update is by polling the io context.
- * We might be able to do this slightly more optimal by removing the
- * O_NONBLOCK flag.
- */
- while (laiocb->ret == -EINPROGRESS) {
- qemu_laio_completion_cb(&laiocb->ctx->e);
- }
-}
-
-static AIOPool laio_pool = {
- .aiocb_size = sizeof(struct qemu_laiocb),
- .cancel = laio_cancel,
-};
-
-BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque, int type)
-{
- struct qemu_laio_state *s = aio_ctx;
- struct qemu_laiocb *laiocb;
- struct iocb *iocbs;
- off_t offset = sector_num * 512;
-
- laiocb = qemu_aio_get(&laio_pool, bs, cb, opaque);
- laiocb->nbytes = nb_sectors * 512;
- laiocb->ctx = s;
- laiocb->ret = -EINPROGRESS;
- laiocb->is_read = (type == QEMU_AIO_READ);
- laiocb->qiov = qiov;
-
- iocbs = &laiocb->iocb;
-
- switch (type) {
- case QEMU_AIO_WRITE:
- io_prep_pwritev(iocbs, fd, qiov->iov, qiov->niov, offset);
- break;
- case QEMU_AIO_READ:
- io_prep_preadv(iocbs, fd, qiov->iov, qiov->niov, offset);
- break;
- /* Currently Linux kernel does not support other operations */
- default:
- fprintf(stderr, "%s: invalid AIO request type 0x%x.\n",
- __func__, type);
- goto out_free_aiocb;
- }
- io_set_eventfd(&laiocb->iocb, event_notifier_get_fd(&s->e));
- s->count++;
-
- if (io_submit(s->ctx, 1, &iocbs) < 0)
- goto out_dec_count;
- return &laiocb->common;
-
-out_dec_count:
- s->count--;
-out_free_aiocb:
- qemu_aio_release(laiocb);
- return NULL;
-}
-
-void *laio_init(void)
-{
- struct qemu_laio_state *s;
-
- s = g_malloc0(sizeof(*s));
- if (event_notifier_init(&s->e, false) < 0) {
- goto out_free_state;
- }
-
- if (io_setup(MAX_EVENTS, &s->ctx) != 0) {
- goto out_close_efd;
- }
-
- qemu_aio_set_event_notifier(&s->e, qemu_laio_completion_cb,
- qemu_laio_flush_cb);
-
- return s;
-
-out_close_efd:
- event_notifier_cleanup(&s->e);
-out_free_state:
- g_free(s);
- return NULL;
-}