From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9xnB-0001b5-Kb for qemu-devel@nongnu.org; Tue, 09 Oct 2018 15:35:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g9xn7-0007Hb-MF for qemu-devel@nongnu.org; Tue, 09 Oct 2018 15:35:39 -0400 From: Kevin Wolf Date: Tue, 9 Oct 2018 21:35:23 +0200 Message-Id: <20181009193524.19052-4-kwolf@redhat.com> In-Reply-To: <20181009193524.19052-1-kwolf@redhat.com> References: <20181009193524.19052-1-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 3/4] nbd: Support auto-read-only option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, eblake@redhat.com, pkrempa@redhat.com, qemu-devel@nongnu.org If read-only=off, but auto-read-only=on are given, open a read-write NBD connection if the server provides a read-write export, but instead of erroring out for read-only exports, just degrade to read-only. Signed-off-by: Kevin Wolf --- block/nbd-client.h | 1 + block/nbd-client.c | 14 +++++++++++--- block/nbd.c | 4 +++- 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/block/nbd-client.h b/block/nbd-client.h index cfc90550b9..1d14e78e92 100644 --- a/block/nbd-client.h +++ b/block/nbd-client.h @@ -46,6 +46,7 @@ int nbd_client_init(BlockDriverState *bs, QCryptoTLSCreds *tlscreds, const char *hostname, const char *x_dirty_bitmap, + bool auto_readonly, Error **errp); void nbd_client_close(BlockDriverState *bs); diff --git a/block/nbd-client.c b/block/nbd-client.c index 9686ecbd5e..6a1e634bec 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -971,6 +971,7 @@ int nbd_client_init(BlockDriverState *bs, QCryptoTLSCreds *tlscreds, const char *hostname, const char *x_dirty_bitmap, + bool auto_readonly, Error **errp) { NBDClientSession *client = nbd_get_client_session(bs); @@ -994,9 +995,16 @@ int nbd_client_init(BlockDriverState *bs, } if (client->info.flags & NBD_FLAG_READ_ONLY && !bdrv_is_read_only(bs)) { - error_setg(errp, - "request for write access conflicts with read-only export"); - return -EACCES; + if (auto_readonly) { + ret = bdrv_set_read_only(bs, true, errp); + if (ret < 0) { + return ret; + } + } else { + error_setg(errp, "request for write access conflicts with " + "read-only export"); + return -EACCES; + } } if (client->info.flags & NBD_FLAG_SEND_FUA) { bs->supported_write_flags = BDRV_REQ_FUA; diff --git a/block/nbd.c b/block/nbd.c index e87699fb73..8c352a45cd 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -445,7 +445,9 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, /* NBD handshake */ ret = nbd_client_init(bs, sioc, s->export, tlscreds, hostname, - qemu_opt_get(opts, "x-dirty-bitmap"), errp); + qemu_opt_get(opts, "x-dirty-bitmap"), + (flags & BDRV_O_AUTO_RDONLY), + errp); error: if (sioc) { object_unref(OBJECT(sioc)); -- 2.13.6