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block: switch posix-aio-compat to threadpool 

This is not meant for portability, but to remove code duplication.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
stable-1.3
Paolo Bonzini 14 years ago
parent
19d092cf9b
commit
47e6b251a5
3 changed files with 41 additions and 399 deletions
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  1. 1
      block/raw-posix-aio.h
  2. 12
      block/raw-posix.c
  3. 427
      posix-aio-compat.c

1
block/raw-posix-aio.h
View File

@ -28,7 +28,6 @@
/* posix-aio-compat.c - thread pool based implementation */
int paio_init(void);
BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque, int type);

12
block/raw-posix.c
View File

@ -266,14 +266,10 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
}
s->fd = fd;
/* We're falling back to POSIX AIO in some cases so init always */
if (paio_init() < 0) {
goto out_close;
}
#ifdef CONFIG_LINUX_AIO
if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {
goto out_close;
qemu_close(fd);
return -errno;
}
#endif
@ -284,10 +280,6 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
#endif
return 0;
out_close:
qemu_close(fd);
return -errno;
}
static int raw_open(BlockDriverState *bs, const char *filename, int flags)

427
posix-aio-compat.c
View File

@ -28,13 +28,12 @@
#include "sysemu.h"
#include "qemu-common.h"
#include "trace.h"
#include "thread-pool.h"
#include "block_int.h"
#include "iov.h"
#include "block/raw-posix-aio.h"
static void do_spawn_thread(void);
struct qemu_paiocb {
BlockDriverAIOCB common;
int aio_fildes;
@ -46,82 +45,15 @@ struct qemu_paiocb {
size_t aio_nbytes;
#define aio_ioctl_cmd aio_nbytes /* for QEMU_AIO_IOCTL */
off_t aio_offset;
QTAILQ_ENTRY(qemu_paiocb) node;
int aio_type;
ssize_t ret;
int active;
struct qemu_paiocb *next;
};
typedef struct PosixAioState {
int rfd, wfd;
struct qemu_paiocb *first_aio;
} PosixAioState;
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
static pthread_t thread_id;
static pthread_attr_t attr;
static int max_threads = 64;
static int cur_threads = 0;
static int idle_threads = 0;
static int new_threads = 0; /* backlog of threads we need to create */
static int pending_threads = 0; /* threads created but not running yet */
static QEMUBH *new_thread_bh;
static QTAILQ_HEAD(, qemu_paiocb) request_list;
#ifdef CONFIG_PREADV
static int preadv_present = 1;
#else
static int preadv_present = 0;
#endif
static void die2(int err, const char *what)
{
fprintf(stderr, "%s failed: %s\n", what, strerror(err));
abort();
}
static void die(const char *what)
{
die2(errno, what);
}
static void mutex_lock(pthread_mutex_t *mutex)
{
int ret = pthread_mutex_lock(mutex);
if (ret) die2(ret, "pthread_mutex_lock");
}
static void mutex_unlock(pthread_mutex_t *mutex)
{
int ret = pthread_mutex_unlock(mutex);
if (ret) die2(ret, "pthread_mutex_unlock");
}
static int cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
struct timespec *ts)
{
int ret = pthread_cond_timedwait(cond, mutex, ts);
if (ret && ret != ETIMEDOUT) die2(ret, "pthread_cond_timedwait");
return ret;
}
static void cond_signal(pthread_cond_t *cond)
{
int ret = pthread_cond_signal(cond);
if (ret) die2(ret, "pthread_cond_signal");
}
static void thread_create(pthread_t *thread, pthread_attr_t *attr,
void *(*start_routine)(void*), void *arg)
{
int ret = pthread_create(thread, attr, start_routine, arg);
if (ret) die2(ret, "pthread_create");
}
static ssize_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb)
{
int ret;
@ -310,286 +242,54 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
return nbytes;
}
static void posix_aio_notify_event(void);
static void *aio_thread(void *unused)
static int aio_worker(void *arg)
{
mutex_lock(&lock);
pending_threads--;
mutex_unlock(&lock);
do_spawn_thread();
while (1) {
struct qemu_paiocb *aiocb;
ssize_t ret = 0;
qemu_timeval tv;
struct timespec ts;
qemu_gettimeofday(&tv);
ts.tv_sec = tv.tv_sec + 10;
ts.tv_nsec = 0;
mutex_lock(&lock);
while (QTAILQ_EMPTY(&request_list) &&
!(ret == ETIMEDOUT)) {
idle_threads++;
ret = cond_timedwait(&cond, &lock, &ts);
idle_threads--;
struct qemu_paiocb *aiocb = arg;
ssize_t ret = 0;
switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
case QEMU_AIO_READ:
ret = handle_aiocb_rw(aiocb);
if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->common.bs->growable) {
/* A short read means that we have reached EOF. Pad the buffer
* with zeros for bytes after EOF. */
iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret,
0, aiocb->aio_nbytes - ret);
ret = aiocb->aio_nbytes;
}
if (QTAILQ_EMPTY(&request_list))
break;
aiocb = QTAILQ_FIRST(&request_list);
QTAILQ_REMOVE(&request_list, aiocb, node);
aiocb->active = 1;
mutex_unlock(&lock);
switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
case QEMU_AIO_READ:
ret = handle_aiocb_rw(aiocb);
if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->common.bs->growable) {
/* A short read means that we have reached EOF. Pad the buffer
* with zeros for bytes after EOF. */
iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret,
0, aiocb->aio_nbytes - ret);
ret = aiocb->aio_nbytes;
}
break;
case QEMU_AIO_WRITE:
ret = handle_aiocb_rw(aiocb);
break;
case QEMU_AIO_FLUSH:
ret = handle_aiocb_flush(aiocb);
break;
case QEMU_AIO_IOCTL:
ret = handle_aiocb_ioctl(aiocb);
break;
default:
fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
if (ret == aiocb->aio_nbytes) {
ret = 0;
} else if (ret >= 0 && ret < aiocb->aio_nbytes) {
ret = -EINVAL;
break;
}
mutex_lock(&lock);
aiocb->ret = ret;
mutex_unlock(&lock);
posix_aio_notify_event();
}
cur_threads--;
mutex_unlock(&lock);
return NULL;
}
static void do_spawn_thread(void)
{
sigset_t set, oldset;
mutex_lock(&lock);
if (!new_threads) {
mutex_unlock(&lock);
return;
}
new_threads--;
pending_threads++;
mutex_unlock(&lock);
/* block all signals */
if (sigfillset(&set)) die("sigfillset");
if (sigprocmask(SIG_SETMASK, &set, &oldset)) die("sigprocmask");
thread_create(&thread_id, &attr, aio_thread, NULL);
if (sigprocmask(SIG_SETMASK, &oldset, NULL)) die("sigprocmask restore");
}
static void spawn_thread_bh_fn(void *opaque)
{
do_spawn_thread();
}
static void spawn_thread(void)
{
cur_threads++;
new_threads++;
/* If there are threads being created, they will spawn new workers, so
* we don't spend time creating many threads in a loop holding a mutex or
* starving the current vcpu.
*
* If there are no idle threads, ask the main thread to create one, so we
* inherit the correct affinity instead of the vcpu affinity.
*/
if (!pending_threads) {
qemu_bh_schedule(new_thread_bh);
}
}
static void qemu_paio_submit(struct qemu_paiocb *aiocb)
{
aiocb->ret = -EINPROGRESS;
aiocb->active = 0;
mutex_lock(&lock);
if (idle_threads == 0 && cur_threads < max_threads)
spawn_thread();
QTAILQ_INSERT_TAIL(&request_list, aiocb, node);
mutex_unlock(&lock);
cond_signal(&cond);
}
static ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
{
ssize_t ret;
mutex_lock(&lock);
ret = aiocb->ret;
mutex_unlock(&lock);
return ret;
}
static int qemu_paio_error(struct qemu_paiocb *aiocb)
{
ssize_t ret = qemu_paio_return(aiocb);
if (ret < 0)
ret = -ret;
else
ret = 0;
return ret;
}
static void posix_aio_read(void *opaque)
{
PosixAioState *s = opaque;
struct qemu_paiocb *acb, **pacb;
int ret;
ssize_t len;
/* read all bytes from signal pipe */
for (;;) {
char bytes[16];
len = read(s->rfd, bytes, sizeof(bytes));
if (len == -1 && errno == EINTR)
continue; /* try again */
if (len == sizeof(bytes))
continue; /* more to read */
break;
}
for(;;) {
pacb = &s->first_aio;
for(;;) {
acb = *pacb;
if (!acb)
return;
ret = qemu_paio_error(acb);
if (ret == ECANCELED) {
/* remove the request */
*pacb = acb->next;
qemu_aio_release(acb);
} else if (ret != EINPROGRESS) {
/* end of aio */
if (ret == 0) {
ret = qemu_paio_return(acb);
if (ret == acb->aio_nbytes)
ret = 0;
else
ret = -EINVAL;
} else {
ret = -ret;
}
trace_paio_complete(acb, acb->common.opaque, ret);
/* remove the request */
*pacb = acb->next;
/* call the callback */
acb->common.cb(acb->common.opaque, ret);
qemu_aio_release(acb);
break;
} else {
pacb = &acb->next;
}
}
}
}
static int posix_aio_flush(void *opaque)
{
PosixAioState *s = opaque;
return !!s->first_aio;
}
static PosixAioState *posix_aio_state;
static void posix_aio_notify_event(void)
{
char byte = 0;
ssize_t ret;
ret = write(posix_aio_state->wfd, &byte, sizeof(byte));
if (ret < 0 && errno != EAGAIN)
die("write()");
}
static void paio_remove(struct qemu_paiocb *acb)
{
struct qemu_paiocb **pacb;
/* remove the callback from the queue */
pacb = &posix_aio_state->first_aio;
for(;;) {
if (*pacb == NULL) {
fprintf(stderr, "paio_remove: aio request not found!\n");
break;
} else if (*pacb == acb) {
*pacb = acb->next;
qemu_aio_release(acb);
break;
case QEMU_AIO_WRITE:
ret = handle_aiocb_rw(aiocb);
if (ret == aiocb->aio_nbytes) {
ret = 0;
} else if (ret >= 0 && ret < aiocb->aio_nbytes) {
ret = -EINVAL;
}
pacb = &(*pacb)->next;
}
}
static void paio_cancel(BlockDriverAIOCB *blockacb)
{
struct qemu_paiocb *acb = (struct qemu_paiocb *)blockacb;
int active = 0;
trace_paio_cancel(acb, acb->common.opaque);
mutex_lock(&lock);
if (!acb->active) {
QTAILQ_REMOVE(&request_list, acb, node);
acb->ret = -ECANCELED;
} else if (acb->ret == -EINPROGRESS) {
active = 1;
}
mutex_unlock(&lock);
if (active) {
/* fail safe: if the aio could not be canceled, we wait for
it */
while (qemu_paio_error(acb) == EINPROGRESS)
;
break;
case QEMU_AIO_FLUSH:
ret = handle_aiocb_flush(aiocb);
break;
case QEMU_AIO_IOCTL:
ret = handle_aiocb_ioctl(aiocb);
break;
default:
fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
ret = -EINVAL;
break;
}
paio_remove(acb);
qemu_aio_release(aiocb);
return ret;
}
static AIOPool raw_aio_pool = {
.aiocb_size = sizeof(struct qemu_paiocb),
.cancel = paio_cancel,
};
BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,
@ -609,12 +309,8 @@ BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,
acb->aio_nbytes = nb_sectors * 512;
acb->aio_offset = sector_num * 512;
acb->next = posix_aio_state->first_aio;
posix_aio_state->first_aio = acb;
trace_paio_submit(acb, opaque, sector_num, nb_sectors, type);
qemu_paio_submit(acb);
return &acb->common;
return thread_pool_submit_aio(aio_worker, acb, cb, opaque);
}
BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
@ -630,50 +326,5 @@ BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
acb->aio_ioctl_buf = buf;
acb->aio_ioctl_cmd = req;
acb->next = posix_aio_state->first_aio;
posix_aio_state->first_aio = acb;
qemu_paio_submit(acb);
return &acb->common;
}
int paio_init(void)
{
PosixAioState *s;
int fds[2];
int ret;
if (posix_aio_state)
return 0;
s = g_malloc(sizeof(PosixAioState));
s->first_aio = NULL;
if (qemu_pipe(fds) == -1) {
fprintf(stderr, "failed to create pipe\n");
g_free(s);
return -1;
}
s->rfd = fds[0];
s->wfd = fds[1];
fcntl(s->rfd, F_SETFL, O_NONBLOCK);
fcntl(s->wfd, F_SETFL, O_NONBLOCK);
qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush, s);
ret = pthread_attr_init(&attr);
if (ret)
die2(ret, "pthread_attr_init");
ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
if (ret)
die2(ret, "pthread_attr_setdetachstate");
QTAILQ_INIT(&request_list);
new_thread_bh = qemu_bh_new(spawn_thread_bh_fn, NULL);
posix_aio_state = s;
return 0;
return thread_pool_submit_aio(aio_worker, acb, cb, opaque);
}

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