From 952ef02c7ee3c2bdbe1856c394ff68b2677b3702 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 17 May 2017 13:09:20 +0200 Subject: [PATCH 14/27] curl: convert readv to coroutines RH-Author: Paolo Bonzini 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 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Jeffrey Cody 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 Signed-off-by: Paolo Bonzini Reviewed-by: Max Reitz Message-id: 20170515100059.15795-7-pbonzini@redhat.com Signed-off-by: Jeff Cody (cherry picked from commit 28256d8246f8905cc41cae3db50e5967059d4600) Signed-off-by: Miroslav Rezanina --- 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; jacb[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