From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41442) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrjs-0003jv-93 for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bWrjo-0005oj-VS for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:36 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51361 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrjo-0005oU-Ib for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:32 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u78Kxnmj071900 for ; Mon, 8 Aug 2016 17:05:32 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0b-001b2d01.pphosted.com with ESMTP id 24nc1q7usp-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 08 Aug 2016 17:05:32 -0400 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Aug 2016 15:05:31 -0600 From: Michael Roth Date: Mon, 8 Aug 2016 16:03:46 -0500 In-Reply-To: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> Message-Id: <1470690267-31454-16-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 15/56] block/nfs: refuse readahead if cache.direct is on List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Lieven , Jeff Cody From: Peter Lieven if we open a NFS export with disabled cache we should refuse the readahead feature as it will cache data inside libnfs. If a export was opened with readahead enabled it should futher not be allowed to disable the cache while running. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Lieven Reviewed-by: Jeff Cody Message-id: 1463662083-20814-2-git-send-email-pl@kamp.de Signed-off-by: Jeff Cody (cherry picked from commit 38f8d5e0251ae7d8257cf099cb3e5a375ef60378) Signed-off-by: Michael Roth --- block/nfs.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/block/nfs.c b/block/nfs.c index 9f51cc3..60be45e 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -1,7 +1,7 @@ /* * QEMU Block driver for native access to files on NFS shares * - * Copyright (c) 2014 Peter Lieven + * Copyright (c) 2014-2016 Peter Lieven * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal @@ -47,6 +47,7 @@ typedef struct NFSClient { bool has_zero_init; AioContext *aio_context; blkcnt_t st_blocks; + bool cache_used; } NFSClient; typedef struct NFSRPC { @@ -278,7 +279,7 @@ static void nfs_file_close(BlockDriverState *bs) } static int64_t nfs_client_open(NFSClient *client, const char *filename, - int flags, Error **errp) + int flags, Error **errp, int open_flags) { int ret = -EINVAL, i; struct stat st; @@ -330,12 +331,18 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename, nfs_set_tcp_syncnt(client->context, val); #ifdef LIBNFS_FEATURE_READAHEAD } else if (!strcmp(qp->p[i].name, "readahead")) { + if (open_flags & BDRV_O_NOCACHE) { + error_setg(errp, "Cannot enable NFS readahead " + "if cache.direct = on"); + goto fail; + } if (val > QEMU_NFS_MAX_READAHEAD_SIZE) { error_report("NFS Warning: Truncating NFS readahead" " size to %d", QEMU_NFS_MAX_READAHEAD_SIZE); val = QEMU_NFS_MAX_READAHEAD_SIZE; } nfs_set_readahead(client->context, val); + client->cache_used = true; #endif #ifdef LIBNFS_FEATURE_DEBUG } else if (!strcmp(qp->p[i].name, "debug")) { @@ -418,7 +425,7 @@ static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags, } ret = nfs_client_open(client, qemu_opt_get(opts, "filename"), (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY, - errp); + errp, bs->open_flags); if (ret < 0) { goto out; } @@ -454,7 +461,7 @@ static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp) total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); - ret = nfs_client_open(client, url, O_CREAT, errp); + ret = nfs_client_open(client, url, O_CREAT, errp, 0); if (ret < 0) { goto out; } @@ -516,6 +523,11 @@ static int nfs_reopen_prepare(BDRVReopenState *state, return -EACCES; } + if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) { + error_setg(errp, "Cannot disable cache if libnfs readahead is enabled"); + return -EINVAL; + } + /* Update cache for read-only reopens */ if (!(state->flags & BDRV_O_RDWR)) { ret = nfs_fstat(client->context, client->fh, &st); -- 1.9.1