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block/archipelago: Use QEMU atomic builtins

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Replace __sync builtins with ones provided by QEMU
for atomic operations.

Special thanks goes to Paolo Bonzini for his refactoring
suggestion in order to use the already existing atomic builtins
interface.

Signed-off-by: Chrysostomos Nanakos <cnanakos@grnet.gr>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Chrysostomos Nanakos 2014-09-02 15:41:34 +03:00 committed by Stefan Hajnoczi
parent 3ba6796d08
commit 072f9ac44a
1 changed files with 23 additions and 53 deletions
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76
block/archipelago.c
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@ -57,6 +57,7 @@
#include "qapi/qmp/qint.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qjson.h"
#include "qemu/atomic.h"
#include <inttypes.h>
#include <xseg/xseg.h>
@ -214,7 +215,7 @@ static void xseg_request_handler(void *state)
xseg_put_request(s->xseg, req, s->srcport);
if ((__sync_add_and_fetch(&segreq->ref, -1)) == 0) {
if (atomic_fetch_dec(&segreq->ref) == 1) {
if (!segreq->failed) {
reqdata->aio_cb->ret = segreq->count;
archipelago_finish_aiocb(reqdata);
@ -233,7 +234,7 @@ static void xseg_request_handler(void *state)
segreq->count += req->serviced;
xseg_put_request(s->xseg, req, s->srcport);
if ((__sync_add_and_fetch(&segreq->ref, -1)) == 0) {
if (atomic_fetch_dec(&segreq->ref) == 1) {
if (!segreq->failed) {
reqdata->aio_cb->ret = segreq->count;
archipelago_finish_aiocb(reqdata);
@ -824,78 +825,47 @@ static int archipelago_aio_segmented_rw(BDRVArchipelagoState *s,
ArchipelagoAIOCB *aio_cb,
int op)
{
int i, ret, segments_nr, last_segment_size;
int ret, segments_nr;
size_t pos = 0;
ArchipelagoSegmentedRequest *segreq;
segreq = g_new(ArchipelagoSegmentedRequest, 1);
segreq = g_new0(ArchipelagoSegmentedRequest, 1);
if (op == ARCHIP_OP_FLUSH) {
segments_nr = 1;
segreq->ref = segments_nr;
segreq->total = count;
segreq->count = 0;
segreq->failed = 0;
ret = archipelago_submit_request(s, 0, count, offset, aio_cb,
segreq, ARCHIP_OP_FLUSH);
if (ret < 0) {
goto err_exit;
}
return 0;
} else {
segments_nr = (int)(count / MAX_REQUEST_SIZE) + \
((count % MAX_REQUEST_SIZE) ? 1 : 0);
}
segments_nr = (int)(count / MAX_REQUEST_SIZE) + \
((count % MAX_REQUEST_SIZE) ? 1 : 0);
last_segment_size = (int)(count % MAX_REQUEST_SIZE);
segreq->ref = segments_nr;
segreq->total = count;
segreq->count = 0;
segreq->failed = 0;
atomic_mb_set(&segreq->ref, segments_nr);
for (i = 0; i < segments_nr - 1; i++) {
ret = archipelago_submit_request(s, i * MAX_REQUEST_SIZE,
MAX_REQUEST_SIZE,
offset + i * MAX_REQUEST_SIZE,
aio_cb, segreq, op);
while (segments_nr > 1) {
ret = archipelago_submit_request(s, pos,
MAX_REQUEST_SIZE,
offset + pos,
aio_cb, segreq, op);
if (ret < 0) {
goto err_exit;
}
count -= MAX_REQUEST_SIZE;
pos += MAX_REQUEST_SIZE;
segments_nr--;
}
if ((segments_nr > 1) && last_segment_size) {
ret = archipelago_submit_request(s, i * MAX_REQUEST_SIZE,
last_segment_size,
offset + i * MAX_REQUEST_SIZE,
aio_cb, segreq, op);
} else if ((segments_nr > 1) && !last_segment_size) {
ret = archipelago_submit_request(s, i * MAX_REQUEST_SIZE,
MAX_REQUEST_SIZE,
offset + i * MAX_REQUEST_SIZE,
aio_cb, segreq, op);
} else if (segments_nr == 1) {
ret = archipelago_submit_request(s, 0, count, offset, aio_cb,
segreq, op);
}
ret = archipelago_submit_request(s, pos, count, offset + pos,
aio_cb, segreq, op);
if (ret < 0) {
goto err_exit;
}
return 0;
err_exit:
__sync_add_and_fetch(&segreq->failed, 1);
if (segments_nr == 1) {
if (__sync_add_and_fetch(&segreq->ref, -1) == 0) {
g_free(segreq);
}
} else {
if ((__sync_add_and_fetch(&segreq->ref, -segments_nr + i)) == 0) {
g_free(segreq);
}
segreq->failed = 1;
if (atomic_fetch_sub(&segreq->ref, segments_nr) == segments_nr) {
g_free(segreq);
}
return ret;
}