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[Qemu-block] [PULL 02/10] block/nfs: refuse readahead if cache.direct is
From: |
Jeff Cody |
Subject: |
[Qemu-block] [PULL 02/10] block/nfs: refuse readahead if cache.direct is on |
Date: |
Tue, 28 Jun 2016 23:10:36 -0400 |
From: Peter Lieven <address@hidden>
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: address@hidden
Signed-off-by: Peter Lieven <address@hidden>
Reviewed-by: Jeff Cody <address@hidden>
Message-id: address@hidden
Signed-off-by: Jeff Cody <address@hidden>
---
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 <address@hidden>
+ * Copyright (c) 2014-2016 Peter Lieven <address@hidden>
*
* 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);
--
1.9.3
- [Qemu-block] [PULL 00/10] Block patches, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 01/10] block/gluster: add support for SEEK_DATA/SEEK_HOLE, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 02/10] block/nfs: refuse readahead if cache.direct is on,
Jeff Cody <=
- [Qemu-block] [PULL 03/10] block/nfs: add support for libnfs pagecache, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 04/10] mirror: fix trace_mirror_yield_in_flight usage in mirror_iteration(), Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 05/10] block/gluster: add support for selecting debug logging level, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 06/10] mirror: clarify mirror_do_read return code, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 07/10] mirror: limit niov to IOV_MAX elements, again, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 08/10] iotests: add small-granularity mirror test, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 09/10] blockjob: assert(cb) when create job, Jeff Cody, 2016/06/28
- [Qemu-block] [PULL 10/10] mirror: fix misleading comments, Jeff Cody, 2016/06/28
- Re: [Qemu-block] [PULL 00/10] Block patches, Peter Maydell, 2016/06/29