From 952ef02c7ee3c2bdbe1856c394ff68b2677b3702 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 17 May 2017 13:09:20 +0200
Subject: [PATCH 14/27] curl: convert readv to coroutines
RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <20170517130921.27402-7-pbonzini@redhat.com>
Patchwork-id: 75268
O-Subject: [RHEL7.4 qemu-kvm PATCH v2 6/7] curl: convert readv to coroutines
Bugzilla: 1437393
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
This is pretty simple. The bottom half goes away because, unlike
bdrv_aio_readv, coroutine-based read can return immediately without
yielding. However, for simplicity I kept the former bottom half
handler in a separate function.
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170515100059.15795-7-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
(cherry picked from commit 28256d8246f8905cc41cae3db50e5967059d4600)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
block/curl.c | 94 ++++++++++++++++++++++++------------------------------------
1 file changed, 38 insertions(+), 56 deletions(-)
diff --git a/block/curl.c b/block/curl.c
index cca6386..acfbe52 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -76,10 +76,6 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
#define CURL_TIMEOUT_DEFAULT 5
#define CURL_TIMEOUT_MAX 10000
-#define FIND_RET_NONE 0
-#define FIND_RET_OK 1
-#define FIND_RET_WAIT 2
-
#define CURL_BLOCK_OPT_URL "url"
#define CURL_BLOCK_OPT_READAHEAD "readahead"
#define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
@@ -93,11 +89,12 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
struct BDRVCURLState;
typedef struct CURLAIOCB {
- BlockAIOCB common;
+ Coroutine *co;
QEMUIOVector *qiov;
uint64_t offset;
uint64_t bytes;
+ int ret;
size_t start;
size_t end;
@@ -268,11 +265,11 @@ static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
request_length - offset);
}
+ acb->ret = 0;
+ s->acb[i] = NULL;
qemu_mutex_unlock(&s->s->mutex);
- acb->common.cb(acb->common.opaque, 0);
+ aio_co_wake(acb->co);
qemu_mutex_lock(&s->s->mutex);
- qemu_aio_unref(acb);
- s->acb[i] = NULL;
}
}
@@ -282,8 +279,8 @@ read_end:
}
/* Called with s->mutex held. */
-static int curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
- CURLAIOCB *acb)
+static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
+ CURLAIOCB *acb)
{
int i;
uint64_t end = start + len;
@@ -312,7 +309,8 @@ static int curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
if (clamped_len < len) {
qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
}
- return FIND_RET_OK;
+ acb->ret = 0;
+ return true;
}
// Wait for unfinished chunks
@@ -330,13 +328,13 @@ static int curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
for (j=0; j<CURL_NUM_ACB; j++) {
if (!state->acb[j]) {
state->acb[j] = acb;
- return FIND_RET_WAIT;
+ return true;
}
}
}
}
- return FIND_RET_NONE;
+ return false;
}
/* Called with s->mutex held. */
@@ -381,11 +379,11 @@ static void curl_multi_check_completion(BDRVCURLState *s)
continue;
}
+ acb->ret = -EIO;
+ state->acb[i] = NULL;
qemu_mutex_unlock(&s->mutex);
- acb->common.cb(acb->common.opaque, -EIO);
+ aio_co_wake(acb->co);
qemu_mutex_lock(&s->mutex);
- qemu_aio_unref(acb);
- state->acb[i] = NULL;
}
}
@@ -822,19 +820,11 @@ out_noclean:
return -EINVAL;
}
-static const AIOCBInfo curl_aiocb_info = {
- .aiocb_size = sizeof(CURLAIOCB),
-};
-
-
-static void curl_readv_bh_cb(void *p)
+static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
{
CURLState *state;
int running;
- int ret = -EINPROGRESS;
- CURLAIOCB *acb = p;
- BlockDriverState *bs = acb->common.bs;
BDRVCURLState *s = bs->opaque;
uint64_t start = acb->offset;
@@ -844,14 +834,8 @@ static void curl_readv_bh_cb(void *p)
// In case we have the requested data already (e.g. read-ahead),
// we can just call the callback and be done.
- switch (curl_find_buf(s, start, acb->bytes, acb)) {
- case FIND_RET_OK:
- ret = 0;
- goto out;
- case FIND_RET_WAIT:
- goto out;
- default:
- break;
+ if (curl_find_buf(s, start, acb->bytes, acb)) {
+ goto out;
}
// No cache found, so let's start a new request
@@ -867,7 +851,7 @@ static void curl_readv_bh_cb(void *p)
if (curl_init_state(s, state) < 0) {
curl_clean_state(state);
- ret = -EIO;
+ acb->ret = -EIO;
goto out;
}
@@ -882,7 +866,7 @@ static void curl_readv_bh_cb(void *p)
state->orig_buf = g_try_malloc(state->buf_len);
if (state->buf_len && state->orig_buf == NULL) {
curl_clean_state(state);
- ret = -ENOMEM;
+ acb->ret = -ENOMEM;
goto out;
}
state->acb[0] = acb;
@@ -899,26 +883,24 @@ static void curl_readv_bh_cb(void *p)
out:
qemu_mutex_unlock(&s->mutex);
- if (ret != -EINPROGRESS) {
- acb->common.cb(acb->common.opaque, ret);
- qemu_aio_unref(acb);
- }
}
-static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
+static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
{
- CURLAIOCB *acb;
-
- acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
-
- acb->qiov = qiov;
- acb->offset = sector_num * BDRV_SECTOR_SIZE;
- acb->bytes = nb_sectors * BDRV_SECTOR_SIZE;
-
- aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
- return &acb->common;
+ CURLAIOCB acb = {
+ .co = qemu_coroutine_self(),
+ .ret = -EINPROGRESS,
+ .qiov = qiov,
+ .offset = offset,
+ .bytes = bytes
+ };
+
+ curl_setup_preadv(bs, &acb);
+ while (acb.ret == -EINPROGRESS) {
+ qemu_coroutine_yield();
+ }
+ return acb.ret;
}
static void curl_close(BlockDriverState *bs)
@@ -949,7 +931,7 @@ static BlockDriver bdrv_http = {
.bdrv_close = curl_close,
.bdrv_getlength = curl_getlength,
- .bdrv_aio_readv = curl_aio_readv,
+ .bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
@@ -965,7 +947,7 @@ static BlockDriver bdrv_https = {
.bdrv_close = curl_close,
.bdrv_getlength = curl_getlength,
- .bdrv_aio_readv = curl_aio_readv,
+ .bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
@@ -981,7 +963,7 @@ static BlockDriver bdrv_ftp = {
.bdrv_close = curl_close,
.bdrv_getlength = curl_getlength,
- .bdrv_aio_readv = curl_aio_readv,
+ .bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
@@ -997,7 +979,7 @@ static BlockDriver bdrv_ftps = {
.bdrv_close = curl_close,
.bdrv_getlength = curl_getlength,
- .bdrv_aio_readv = curl_aio_readv,
+ .bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
--
1.8.3.1