Message ID | 20170510143205.32013-7-pbonzini@redhat.com |
---|---|
State | New |
Headers | show |
On Wed, May 10, 2017 at 04:32:04PM +0200, Paolo Bonzini wrote: > 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. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > block/curl.c | 94 ++++++++++++++++++++++++------------------------------------ > 1 file changed, 38 insertions(+), 56 deletions(-) > > diff --git a/block/curl.c b/block/curl.c > index 3e288f2bc7..80870bd60c 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; > } > } > > @@ -821,19 +819,11 @@ 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; > @@ -843,14 +833,8 @@ 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 > @@ -866,7 +850,7 @@ 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; > } > > @@ -881,7 +865,7 @@ 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; > @@ -898,26 +882,24 @@ 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) > @@ -948,7 +930,7 @@ 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, > @@ -964,7 +946,7 @@ 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, > @@ -980,7 +962,7 @@ 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, > @@ -996,7 +978,7 @@ 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, > -- > 2.12.2 > > Reviewed-by: Jeff Cody <jcody@redhat.com>
diff --git a/block/curl.c b/block/curl.c index 3e288f2bc7..80870bd60c 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; } } @@ -821,19 +819,11 @@ 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; @@ -843,14 +833,8 @@ 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 @@ -866,7 +850,7 @@ 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; } @@ -881,7 +865,7 @@ 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; @@ -898,26 +882,24 @@ 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) @@ -948,7 +930,7 @@ 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, @@ -964,7 +946,7 @@ 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, @@ -980,7 +962,7 @@ 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, @@ -996,7 +978,7 @@ 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,
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. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- block/curl.c | 94 ++++++++++++++++++++++++------------------------------------ 1 file changed, 38 insertions(+), 56 deletions(-)