commit e916e9e47a6a932872641d0da1f7bd4927b63fee
Author: Steve Dickson <steved@redhat.com>
Date: Mon Aug 13 11:04:02 2007 -0400
Adds support for the 'nosharecache' mount option to nfs-utils.
Signed-off-by: Steve Dickson <steved@redhat.com>
diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
index 673556c..e66daba 100644
--- a/utils/mount/nfs.man
+++ b/utils/mount/nfs.man
@@ -288,6 +288,23 @@ Mount the NFS filesystem using the UDP protocol.
Disables NFSv3 READDIRPLUS RPCs. Use this option when
mounting servers that don't support or have broken
READDIRPLUS implementations.
+.TP 1.5i
+.I nosharecache
+As of kernel 2.6.18, it is no longer possible to mount the same
+same filesystem with different mount options to a new mountpoint.
+It was deemed unsafe to do so, since cached data cannot be shared
+between the two mountpoints. In consequence, files or directories
+that were common to both mountpoint subtrees could often be seen to
+be out of sync following an update.
+.br
+This option allows administrators to select the pre-2.6.18 behaviour,
+permitting the same filesystem to be mounted with different mount
+options.
+.br
+.B Beware:
+Use of this option is not recommended unless you are certain that there
+are no hard links or subtrees of this mountpoint that are mounted
+elsewhere.
.P
All of the non-value options have corresponding nooption forms.
For example, nointr means don't allow file operations to be
@@ -444,6 +461,23 @@ This extracts a
server performance penalty but it allows two different NFS clients
to get reasonable good results when both clients are actively
writing to common filesystem on the server.
+.TP 1.5i
+.I nosharecache
+As of kernel 2.6.18, it is no longer possible to mount the same
+same filesystem with different mount options to a new mountpoint.
+It was deemed unsafe to do so, since cached data cannot be shared
+between the two mountpoints. In consequence, files or directories
+that were common to both mountpoint subtrees could often be seen to
+be out of sync following an update.
+.br
+This option allows administrators to select the pre-2.6.18 behaviour,
+permitting the same filesystem to be mounted with different mount
+options.
+.br
+.B Beware:
+Use of this option is not recommended unless you are certain that there
+are no hard links or subtrees of this mountpoint that are mounted
+elsewhere.
.P
All of the non-value options have corresponding nooption forms.
For example, nointr means don't allow file operations to be
diff --git a/utils/mount/nfs4_mount.h b/utils/mount/nfs4_mount.h
index 74c9b95..2fcca6d 100644
--- a/utils/mount/nfs4_mount.h
+++ b/utils/mount/nfs4_mount.h
@@ -65,6 +65,7 @@ struct nfs4_mount_data {
#define NFS4_MOUNT_NOCTO 0x0010 /* 1 */
#define NFS4_MOUNT_NOAC 0x0020 /* 1 */
#define NFS4_MOUNT_STRICTLOCK 0x1000 /* 1 */
+#define NFS4_MOUNT_UNSHARED 0x8000 /* 5 */
#define NFS4_MOUNT_FLAGMASK 0xFFFF
/* pseudoflavors: */
diff --git a/utils/mount/nfs4mount.c b/utils/mount/nfs4mount.c
index 2a58d0a..0376f32 100644
--- a/utils/mount/nfs4mount.c
+++ b/utils/mount/nfs4mount.c
@@ -201,7 +201,7 @@ int nfs4mount(const char *spec, const char *node, int *flags,
char *s;
int val;
int bg, soft, intr;
- int nocto, noac;
+ int nocto, noac, unshared;
int retry;
int retval;
time_t timeout, t;
@@ -252,6 +252,7 @@ int nfs4mount(const char *spec, const char *node, int *flags,
intr = NFS4_MOUNT_INTR;
nocto = 0;
noac = 0;
+ unshared = 0;
retry = 10000; /* 10000 minutes ~ 1 week */
/*
@@ -336,6 +337,8 @@ int nfs4mount(const char *spec, const char *node, int *flags,
nocto = !val;
else if (!strcmp(opt, "ac"))
noac = !val;
+ else if (!strcmp(opt, "sharecache"))
+ unshared = !val;
else if (!sloppy) {
printf(_("unknown nfs mount option: "
"%s%s\n"), val ? "" : "no", opt);
@@ -347,7 +350,8 @@ int nfs4mount(const char *spec, const char *node, int *flags,
data.flags = (soft ? NFS4_MOUNT_SOFT : 0)
| (intr ? NFS4_MOUNT_INTR : 0)
| (nocto ? NFS4_MOUNT_NOCTO : 0)
- | (noac ? NFS4_MOUNT_NOAC : 0);
+ | (noac ? NFS4_MOUNT_NOAC : 0)
+ | (unshared ? NFS4_MOUNT_UNSHARED : 0);
/*
* Give a warning if the rpc.idmapd daemon is not running
@@ -388,11 +392,13 @@ int nfs4mount(const char *spec, const char *node, int *flags,
data.acregmin, data.acregmax, data.acdirmin, data.acdirmax);
printf("port = %d, bg = %d, retry = %d, flags = %.8x\n",
ntohs(server_addr.sin_port), bg, retry, data.flags);
- printf("soft = %d, intr = %d, nocto = %d, noac = %d\n",
+ printf("soft = %d, intr = %d, nocto = %d, noac = %d, "
+ "nosharecache = %d\n",
(data.flags & NFS4_MOUNT_SOFT) != 0,
(data.flags & NFS4_MOUNT_INTR) != 0,
(data.flags & NFS4_MOUNT_NOCTO) != 0,
- (data.flags & NFS4_MOUNT_NOAC) != 0);
+ (data.flags & NFS4_MOUNT_NOAC) != 0,
+ (data.flags & NFS4_MOUNT_UNSHARED) != 0);
if (num_flavour > 0) {
int pf_cnt, i;
diff --git a/utils/mount/nfs_mount.h b/utils/mount/nfs_mount.h
index 4a061d8..50ce2a8 100644
--- a/utils/mount/nfs_mount.h
+++ b/utils/mount/nfs_mount.h
@@ -64,6 +64,7 @@ struct nfs_mount_data {
#define NFS_MOUNT_NOACL 0x0800 /* 4 */
#define NFS_MOUNT_SECFLAVOUR 0x2000 /* 5 */
#define NFS_MOUNT_NORDIRPLUS 0x4000 /* 5 */
+#define NFS_MOUNT_UNSHARED 0x8000 /* 5 */
/* security pseudoflavors */
diff --git a/utils/mount/nfsmount.c b/utils/mount/nfsmount.c
index 815064a..f21aaff 100644
--- a/utils/mount/nfsmount.c
+++ b/utils/mount/nfsmount.c
@@ -804,6 +804,10 @@ parse_options(char *old_opts, struct nfs_mount_data *data,
data->flags &= ~NFS_MOUNT_NORDIRPLUS;
if (!val)
data->flags |= NFS_MOUNT_NORDIRPLUS;
+ } else if (!strcmp(opt, "sharecache")) {
+ data->flags &= ~NFS_MOUNT_UNSHARED;
+ if (!val)
+ data->flags |= NFS_MOUNT_UNSHARED;
#endif
} else {
bad_option: