From f53a829bb9ef14be800556cbc02d8b20fc1050a7 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 6 Feb 2015 16:06:16 -0500 Subject: [PATCH] nbd: Drop BDS backpointer Before this patch, the "opaque" pointer in an NBD BDS points to a BDRVNBDState, which contains an NbdClientSession object, which in turn contains a pointer to the BDS. This pointer may become invalid due to bdrv_swap(), so drop it, and instead pass the BDS directly to the nbd-client.c functions which then retrieve the NbdClientSession object from there. Signed-off-by: Max Reitz Reviewed-by: Paolo Bonzini Message-id: 1423256778-3340-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi --- block/nbd-client.c | 101 +++++++++++++++++++++++++++------------------------- block/nbd-client.h | 34 +++++++++--------- block/nbd.c | 37 ++++++++----------- include/block/nbd.h | 1 - nbd.c | 8 ++--- 5 files changed, 87 insertions(+), 94 deletions(-) diff --git a/block/nbd-client.c b/block/nbd-client.c index 28bfb62bed..a01a37fec8 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -43,20 +43,23 @@ static void nbd_recv_coroutines_enter_all(NbdClientSession *s) } } -static void nbd_teardown_connection(NbdClientSession *client) +static void nbd_teardown_connection(BlockDriverState *bs) { + NbdClientSession *client = nbd_get_client_session(bs); + /* finish any pending coroutines */ shutdown(client->sock, 2); nbd_recv_coroutines_enter_all(client); - nbd_client_session_detach_aio_context(client); + nbd_client_detach_aio_context(bs); closesocket(client->sock); client->sock = -1; } static void nbd_reply_ready(void *opaque) { - NbdClientSession *s = opaque; + BlockDriverState *bs = opaque; + NbdClientSession *s = nbd_get_client_session(bs); uint64_t i; int ret; @@ -89,28 +92,29 @@ static void nbd_reply_ready(void *opaque) } fail: - nbd_teardown_connection(s); + nbd_teardown_connection(bs); } static void nbd_restart_write(void *opaque) { - NbdClientSession *s = opaque; + BlockDriverState *bs = opaque; - qemu_coroutine_enter(s->send_coroutine, NULL); + qemu_coroutine_enter(nbd_get_client_session(bs)->send_coroutine, NULL); } -static int nbd_co_send_request(NbdClientSession *s, - struct nbd_request *request, - QEMUIOVector *qiov, int offset) +static int nbd_co_send_request(BlockDriverState *bs, + struct nbd_request *request, + QEMUIOVector *qiov, int offset) { + NbdClientSession *s = nbd_get_client_session(bs); AioContext *aio_context; int rc, ret; qemu_co_mutex_lock(&s->send_mutex); s->send_coroutine = qemu_coroutine_self(); - aio_context = bdrv_get_aio_context(s->bs); + aio_context = bdrv_get_aio_context(bs); aio_set_fd_handler(aio_context, s->sock, - nbd_reply_ready, nbd_restart_write, s); + nbd_reply_ready, nbd_restart_write, bs); if (qiov) { if (!s->is_unix) { socket_set_cork(s->sock, 1); @@ -129,7 +133,7 @@ static int nbd_co_send_request(NbdClientSession *s, } else { rc = nbd_send_request(s->sock, request); } - aio_set_fd_handler(aio_context, s->sock, nbd_reply_ready, NULL, s); + aio_set_fd_handler(aio_context, s->sock, nbd_reply_ready, NULL, bs); s->send_coroutine = NULL; qemu_co_mutex_unlock(&s->send_mutex); return rc; @@ -195,10 +199,11 @@ static void nbd_coroutine_end(NbdClientSession *s, } } -static int nbd_co_readv_1(NbdClientSession *client, int64_t sector_num, +static int nbd_co_readv_1(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int offset) { + NbdClientSession *client = nbd_get_client_session(bs); struct nbd_request request = { .type = NBD_CMD_READ }; struct nbd_reply reply; ssize_t ret; @@ -207,7 +212,7 @@ static int nbd_co_readv_1(NbdClientSession *client, int64_t sector_num, request.len = nb_sectors * 512; nbd_coroutine_start(client, &request); - ret = nbd_co_send_request(client, &request, NULL, 0); + ret = nbd_co_send_request(bs, &request, NULL, 0); if (ret < 0) { reply.error = -ret; } else { @@ -218,15 +223,16 @@ static int nbd_co_readv_1(NbdClientSession *client, int64_t sector_num, } -static int nbd_co_writev_1(NbdClientSession *client, int64_t sector_num, +static int nbd_co_writev_1(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int offset) { + NbdClientSession *client = nbd_get_client_session(bs); struct nbd_request request = { .type = NBD_CMD_WRITE }; struct nbd_reply reply; ssize_t ret; - if (!bdrv_enable_write_cache(client->bs) && + if (!bdrv_enable_write_cache(bs) && (client->nbdflags & NBD_FLAG_SEND_FUA)) { request.type |= NBD_CMD_FLAG_FUA; } @@ -235,7 +241,7 @@ static int nbd_co_writev_1(NbdClientSession *client, int64_t sector_num, request.len = nb_sectors * 512; nbd_coroutine_start(client, &request); - ret = nbd_co_send_request(client, &request, qiov, offset); + ret = nbd_co_send_request(bs, &request, qiov, offset); if (ret < 0) { reply.error = -ret; } else { @@ -249,14 +255,13 @@ static int nbd_co_writev_1(NbdClientSession *client, int64_t sector_num, * remain aligned to 4K. */ #define NBD_MAX_SECTORS 2040 -int nbd_client_session_co_readv(NbdClientSession *client, int64_t sector_num, - int nb_sectors, QEMUIOVector *qiov) +int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) { int offset = 0; int ret; while (nb_sectors > NBD_MAX_SECTORS) { - ret = nbd_co_readv_1(client, sector_num, - NBD_MAX_SECTORS, qiov, offset); + ret = nbd_co_readv_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset); if (ret < 0) { return ret; } @@ -264,17 +269,16 @@ int nbd_client_session_co_readv(NbdClientSession *client, int64_t sector_num, sector_num += NBD_MAX_SECTORS; nb_sectors -= NBD_MAX_SECTORS; } - return nbd_co_readv_1(client, sector_num, nb_sectors, qiov, offset); + return nbd_co_readv_1(bs, sector_num, nb_sectors, qiov, offset); } -int nbd_client_session_co_writev(NbdClientSession *client, int64_t sector_num, - int nb_sectors, QEMUIOVector *qiov) +int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) { int offset = 0; int ret; while (nb_sectors > NBD_MAX_SECTORS) { - ret = nbd_co_writev_1(client, sector_num, - NBD_MAX_SECTORS, qiov, offset); + ret = nbd_co_writev_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset); if (ret < 0) { return ret; } @@ -282,11 +286,12 @@ int nbd_client_session_co_writev(NbdClientSession *client, int64_t sector_num, sector_num += NBD_MAX_SECTORS; nb_sectors -= NBD_MAX_SECTORS; } - return nbd_co_writev_1(client, sector_num, nb_sectors, qiov, offset); + return nbd_co_writev_1(bs, sector_num, nb_sectors, qiov, offset); } -int nbd_client_session_co_flush(NbdClientSession *client) +int nbd_client_co_flush(BlockDriverState *bs) { + NbdClientSession *client = nbd_get_client_session(bs); struct nbd_request request = { .type = NBD_CMD_FLUSH }; struct nbd_reply reply; ssize_t ret; @@ -303,7 +308,7 @@ int nbd_client_session_co_flush(NbdClientSession *client) request.len = 0; nbd_coroutine_start(client, &request); - ret = nbd_co_send_request(client, &request, NULL, 0); + ret = nbd_co_send_request(bs, &request, NULL, 0); if (ret < 0) { reply.error = -ret; } else { @@ -313,9 +318,10 @@ int nbd_client_session_co_flush(NbdClientSession *client) return -reply.error; } -int nbd_client_session_co_discard(NbdClientSession *client, int64_t sector_num, - int nb_sectors) +int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) { + NbdClientSession *client = nbd_get_client_session(bs); struct nbd_request request = { .type = NBD_CMD_TRIM }; struct nbd_reply reply; ssize_t ret; @@ -327,7 +333,7 @@ int nbd_client_session_co_discard(NbdClientSession *client, int64_t sector_num, request.len = nb_sectors * 512; nbd_coroutine_start(client, &request); - ret = nbd_co_send_request(client, &request, NULL, 0); + ret = nbd_co_send_request(bs, &request, NULL, 0); if (ret < 0) { reply.error = -ret; } else { @@ -338,43 +344,41 @@ int nbd_client_session_co_discard(NbdClientSession *client, int64_t sector_num, } -void nbd_client_session_detach_aio_context(NbdClientSession *client) +void nbd_client_detach_aio_context(BlockDriverState *bs) { - aio_set_fd_handler(bdrv_get_aio_context(client->bs), client->sock, - NULL, NULL, NULL); + aio_set_fd_handler(bdrv_get_aio_context(bs), + nbd_get_client_session(bs)->sock, NULL, NULL, NULL); } -void nbd_client_session_attach_aio_context(NbdClientSession *client, - AioContext *new_context) +void nbd_client_attach_aio_context(BlockDriverState *bs, + AioContext *new_context) { - aio_set_fd_handler(new_context, client->sock, - nbd_reply_ready, NULL, client); + aio_set_fd_handler(new_context, nbd_get_client_session(bs)->sock, + nbd_reply_ready, NULL, bs); } -void nbd_client_session_close(NbdClientSession *client) +void nbd_client_close(BlockDriverState *bs) { + NbdClientSession *client = nbd_get_client_session(bs); struct nbd_request request = { .type = NBD_CMD_DISC, .from = 0, .len = 0 }; - if (!client->bs) { - return; - } if (client->sock == -1) { return; } nbd_send_request(client->sock, &request); - nbd_teardown_connection(client); - client->bs = NULL; + nbd_teardown_connection(bs); } -int nbd_client_session_init(NbdClientSession *client, BlockDriverState *bs, - int sock, const char *export, Error **errp) +int nbd_client_init(BlockDriverState *bs, int sock, const char *export, + Error **errp) { + NbdClientSession *client = nbd_get_client_session(bs); int ret; /* NBD handshake */ @@ -391,13 +395,12 @@ int nbd_client_session_init(NbdClientSession *client, BlockDriverState *bs, qemu_co_mutex_init(&client->send_mutex); qemu_co_mutex_init(&client->free_sema); - client->bs = bs; client->sock = sock; /* Now that we're connected, set the socket to be non-blocking and * kick the reply mechanism. */ qemu_set_nonblock(sock); - nbd_client_session_attach_aio_context(client, bdrv_get_aio_context(bs)); + nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs)); logout("Established connection with NBD server\n"); return 0; diff --git a/block/nbd-client.h b/block/nbd-client.h index cfeecc2775..fa4ff42d22 100644 --- a/block/nbd-client.h +++ b/block/nbd-client.h @@ -31,24 +31,24 @@ typedef struct NbdClientSession { struct nbd_reply reply; bool is_unix; - - BlockDriverState *bs; } NbdClientSession; -int nbd_client_session_init(NbdClientSession *client, BlockDriverState *bs, - int sock, const char *export_name, Error **errp); -void nbd_client_session_close(NbdClientSession *client); - -int nbd_client_session_co_discard(NbdClientSession *client, int64_t sector_num, - int nb_sectors); -int nbd_client_session_co_flush(NbdClientSession *client); -int nbd_client_session_co_writev(NbdClientSession *client, int64_t sector_num, - int nb_sectors, QEMUIOVector *qiov); -int nbd_client_session_co_readv(NbdClientSession *client, int64_t sector_num, - int nb_sectors, QEMUIOVector *qiov); - -void nbd_client_session_detach_aio_context(NbdClientSession *client); -void nbd_client_session_attach_aio_context(NbdClientSession *client, - AioContext *new_context); +NbdClientSession *nbd_get_client_session(BlockDriverState *bs); + +int nbd_client_init(BlockDriverState *bs, int sock, const char *export_name, + Error **errp); +void nbd_client_close(BlockDriverState *bs); + +int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num, + int nb_sectors); +int nbd_client_co_flush(BlockDriverState *bs); +int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov); +int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov); + +void nbd_client_detach_aio_context(BlockDriverState *bs); +void nbd_client_attach_aio_context(BlockDriverState *bs, + AioContext *new_context); #endif /* NBD_CLIENT_H */ diff --git a/block/nbd.c b/block/nbd.c index b05d1d0407..2f3b9adf72 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -224,6 +224,12 @@ static void nbd_config(BDRVNBDState *s, QDict *options, char **export, } } +NbdClientSession *nbd_get_client_session(BlockDriverState *bs) +{ + BDRVNBDState *s = bs->opaque; + return &s->client; +} + static int nbd_establish_connection(BlockDriverState *bs, Error **errp) { BDRVNBDState *s = bs->opaque; @@ -271,7 +277,7 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, } /* NBD handshake */ - result = nbd_client_session_init(&s->client, bs, sock, export, errp); + result = nbd_client_init(bs, sock, export, errp); g_free(export); return result; } @@ -279,26 +285,18 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { - BDRVNBDState *s = bs->opaque; - - return nbd_client_session_co_readv(&s->client, sector_num, - nb_sectors, qiov); + return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov); } static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { - BDRVNBDState *s = bs->opaque; - - return nbd_client_session_co_writev(&s->client, sector_num, - nb_sectors, qiov); + return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov); } static int nbd_co_flush(BlockDriverState *bs) { - BDRVNBDState *s = bs->opaque; - - return nbd_client_session_co_flush(&s->client); + return nbd_client_co_flush(bs); } static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) @@ -310,10 +308,7 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { - BDRVNBDState *s = bs->opaque; - - return nbd_client_session_co_discard(&s->client, sector_num, - nb_sectors); + return nbd_client_co_discard(bs, sector_num, nb_sectors); } static void nbd_close(BlockDriverState *bs) @@ -321,7 +316,7 @@ static void nbd_close(BlockDriverState *bs) BDRVNBDState *s = bs->opaque; qemu_opts_del(s->socket_opts); - nbd_client_session_close(&s->client); + nbd_client_close(bs); } static int64_t nbd_getlength(BlockDriverState *bs) @@ -333,17 +328,13 @@ static int64_t nbd_getlength(BlockDriverState *bs) static void nbd_detach_aio_context(BlockDriverState *bs) { - BDRVNBDState *s = bs->opaque; - - nbd_client_session_detach_aio_context(&s->client); + nbd_client_detach_aio_context(bs); } static void nbd_attach_aio_context(BlockDriverState *bs, AioContext *new_context) { - BDRVNBDState *s = bs->opaque; - - nbd_client_session_attach_aio_context(&s->client, new_context); + nbd_client_attach_aio_context(bs, new_context); } static void nbd_refresh_filename(BlockDriverState *bs) diff --git a/include/block/nbd.h b/include/block/nbd.h index b75959556c..ca9a5ac5b3 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -99,7 +99,6 @@ void nbd_export_close_all(void); NBDClient *nbd_client_new(NBDExport *exp, int csock, void (*close)(NBDClient *)); -void nbd_client_close(NBDClient *client); void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); diff --git a/nbd.c b/nbd.c index e56afbc162..71159aff6a 100644 --- a/nbd.c +++ b/nbd.c @@ -874,7 +874,7 @@ void nbd_client_put(NBDClient *client) { if (--client->refcount == 0) { /* The last reference should be dropped by client->close, - * which is called by nbd_client_close. + * which is called by client_close. */ assert(client->closing); @@ -889,7 +889,7 @@ void nbd_client_put(NBDClient *client) } } -void nbd_client_close(NBDClient *client) +static void client_close(NBDClient *client) { if (client->closing) { return; @@ -1026,7 +1026,7 @@ void nbd_export_close(NBDExport *exp) nbd_export_get(exp); QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { - nbd_client_close(client); + client_close(client); } nbd_export_set_name(exp, NULL); nbd_export_put(exp); @@ -1311,7 +1311,7 @@ done: out: nbd_request_put(req); - nbd_client_close(client); + client_close(client); } static void nbd_read(void *opaque) -- 2.11.0