[Qemu-devel] [RFC 12/13] dataplane: drop ioq Linux AIO request queue

[Stefan Hajnoczi <stefanha@redhat.com>]

virtio-blk data plane used a custom Linux AIO request queue called
"ioq".  Now that virtio-blk data plane uses the QEMU block layer we can
drop ioq.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/dataplane/Makefile.objs |   2 +-
 hw/block/dataplane/ioq.c         | 117 ---------------------------------------
 hw/block/dataplane/ioq.h         |  57 -------------------
 3 files changed, 1 insertion(+), 175 deletions(-)
 delete mode 100644 hw/block/dataplane/ioq.c
 delete mode 100644 hw/block/dataplane/ioq.h

diff --git a/hw/block/dataplane/Makefile.objs b/hw/block/dataplane/Makefile.objs
index 9da2eb8..e786f66 100644
--- a/hw/block/dataplane/Makefile.objs
+++ b/hw/block/dataplane/Makefile.objs
@@ -1 +1 @@
-obj-y += ioq.o virtio-blk.o
+obj-y += virtio-blk.o
diff --git a/hw/block/dataplane/ioq.c b/hw/block/dataplane/ioq.c
deleted file mode 100644
index f709f87..0000000
--- a/hw/block/dataplane/ioq.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*
- * Linux AIO request queue
- *
- * Copyright 2012 IBM, Corp.
- * Copyright 2012 Red Hat, Inc. and/or its affiliates
- *
- * Authors:
- *   Stefan Hajnoczi <stefanha@redhat.com>
- *
- * 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 "ioq.h"
-
-void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs)
-{
-    int rc;
-
-    ioq->fd = fd;
-    ioq->max_reqs = max_reqs;
-
-    memset(&ioq->io_ctx, 0, sizeof ioq->io_ctx);
-    rc = io_setup(max_reqs, &ioq->io_ctx);
-    if (rc != 0) {
-        fprintf(stderr, "ioq io_setup failed %d\n", rc);
-        exit(1);
-    }
-
-    rc = event_notifier_init(&ioq->io_notifier, 0);
-    if (rc != 0) {
-        fprintf(stderr, "ioq io event notifier creation failed %d\n", rc);
-        exit(1);
-    }
-
-    ioq->freelist = g_malloc0(sizeof ioq->freelist[0] * max_reqs);
-    ioq->freelist_idx = 0;
-
-    ioq->queue = g_malloc0(sizeof ioq->queue[0] * max_reqs);
-    ioq->queue_idx = 0;
-}
-
-void ioq_cleanup(IOQueue *ioq)
-{
-    g_free(ioq->freelist);
-    g_free(ioq->queue);
-
-    event_notifier_cleanup(&ioq->io_notifier);
-    io_destroy(ioq->io_ctx);
-}
-
-EventNotifier *ioq_get_notifier(IOQueue *ioq)
-{
-    return &ioq->io_notifier;
-}
-
-struct iocb *ioq_get_iocb(IOQueue *ioq)
-{
-    /* Underflow cannot happen since ioq is sized for max_reqs */
-    assert(ioq->freelist_idx != 0);
-
-    struct iocb *iocb = ioq->freelist[--ioq->freelist_idx];
-    ioq->queue[ioq->queue_idx++] = iocb;
-    return iocb;
-}
-
-void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb)
-{
-    /* Overflow cannot happen since ioq is sized for max_reqs */
-    assert(ioq->freelist_idx != ioq->max_reqs);
-
-    ioq->freelist[ioq->freelist_idx++] = iocb;
-}
-
-struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
-                      unsigned int count, long long offset)
-{
-    struct iocb *iocb = ioq_get_iocb(ioq);
-
-    if (read) {
-        io_prep_preadv(iocb, ioq->fd, iov, count, offset);
-    } else {
-        io_prep_pwritev(iocb, ioq->fd, iov, count, offset);
-    }
-    io_set_eventfd(iocb, event_notifier_get_fd(&ioq->io_notifier));
-    return iocb;
-}
-
-int ioq_submit(IOQueue *ioq)
-{
-    int rc = io_submit(ioq->io_ctx, ioq->queue_idx, ioq->queue);
-    ioq->queue_idx = 0; /* reset */
-    return rc;
-}
-
-int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
-                       void *opaque)
-{
-    struct io_event events[ioq->max_reqs];
-    int nevents, i;
-
-    do {
-        nevents = io_getevents(ioq->io_ctx, 0, ioq->max_reqs, events, NULL);
-    } while (nevents < 0 && errno == EINTR);
-    if (nevents < 0) {
-        return nevents;
-    }
-
-    for (i = 0; i < nevents; i++) {
-        ssize_t ret = ((uint64_t)events[i].res2 << 32) | events[i].res;
-
-        completion(events[i].obj, ret, opaque);
-        ioq_put_iocb(ioq, events[i].obj);
-    }
-    return nevents;
-}
diff --git a/hw/block/dataplane/ioq.h b/hw/block/dataplane/ioq.h
deleted file mode 100644
index b49b5de..0000000
--- a/hw/block/dataplane/ioq.h
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Linux AIO request queue
- *
- * Copyright 2012 IBM, Corp.
- * Copyright 2012 Red Hat, Inc. and/or its affiliates
- *
- * Authors:
- *   Stefan Hajnoczi <stefanha@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#ifndef IOQ_H
-#define IOQ_H
-
-#include <libaio.h>
-#include "qemu/event_notifier.h"
-
-typedef struct {
-    int fd;                         /* file descriptor */
-    unsigned int max_reqs;          /* max length of freelist and queue */
-
-    io_context_t io_ctx;            /* Linux AIO context */
-    EventNotifier io_notifier;      /* Linux AIO eventfd */
-
-    /* Requests can complete in any order so a free list is necessary to manage
-     * available iocbs.
-     */
-    struct iocb **freelist;         /* free iocbs */
-    unsigned int freelist_idx;
-
-    /* Multiple requests are queued up before submitting them all in one go */
-    struct iocb **queue;            /* queued iocbs */
-    unsigned int queue_idx;
-} IOQueue;
-
-void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs);
-void ioq_cleanup(IOQueue *ioq);
-EventNotifier *ioq_get_notifier(IOQueue *ioq);
-struct iocb *ioq_get_iocb(IOQueue *ioq);
-void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb);
-struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
-                      unsigned int count, long long offset);
-int ioq_submit(IOQueue *ioq);
-
-static inline unsigned int ioq_num_queued(IOQueue *ioq)
-{
-    return ioq->queue_idx;
-}
-
-typedef void IOQueueCompletion(struct iocb *iocb, ssize_t ret, void *opaque);
-int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
-                       void *opaque);
-
-#endif /* IOQ_H */
-- 
1.8.1.4