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| author | NeilBrown <neilb@suse.com> | 2017-06-01 09:42:16 -0400 |
|---|---|---|
| committer | Steve Dickson <steved@redhat.com> | 2017-06-01 09:52:29 -0400 |
| commit | d406648690fa0fdf5333d7d54cf8210dab7f4d9c (patch) | |
| tree | 7c8de5cb2b0e3a9921f490d87dfbd1d2218db106 | |
| parent | 0277815d9509ffc197c27973313f364616245704 (diff) | |
| download | nfs-utils-d406648690fa0fdf5333d7d54cf8210dab7f4d9c.tar.gz nfs-utils-d406648690fa0fdf5333d7d54cf8210dab7f4d9c.tar.xz nfs-utils-d406648690fa0fdf5333d7d54cf8210dab7f4d9c.zip | |
mount.nfs: improve version negotiation when vers=4 is specified.
If NFSv4, in general, is requested (possibly by -t nfs4 or -o v4 or -o
vers=4 etc) then we need to negotiate the best minor version, but must
not fallback to v3 or v2. Internally, this state is reflected in v_mode
== V_GENERAL. This means that a major version was given, but the minor
version still needs to be negotiated.
This is handled by nfs_autonegotiate(). It currently does the right
thing for EPROTONOSUPPORT and EINVAL, but not for other errors.
In particular, ENOENT can cause problems as NFSv4 might export
a different namespace than NFSv3 (e.g. by using fsid=0 in the Linux
NFS server). Currently a mount request for NFSv4 and a particular path
can result if an NFSv3 mount if the path is available with v3 but
not v4.
So move the special handling of V_GENERAL into the common fall_back:
code, and add extra checking in the ENCONNREFUSED case, which does
not use fall_back:.
Tested-by: Steve Dickson <steved@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
| -rw-r--r-- | utils/mount/stropts.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c index 0fbb375..c0266e5 100644 --- a/utils/mount/stropts.c +++ b/utils/mount/stropts.c @@ -315,9 +315,10 @@ static int nfs_set_version(struct nfsmount_info *mi) if (!nfs_nfs_version(mi->options, &mi->version)) return 0; - if (strncmp(mi->type, "nfs4", 4) == 0) + if (strncmp(mi->type, "nfs4", 4) == 0) { mi->version.major = 4; - + mi->version.v_mode = V_GENERAL; + } /* * Before 2.6.32, the kernel NFS client didn't * support "-t nfs vers=4" mounts, so NFS version @@ -838,9 +839,6 @@ check_result: case EINVAL: /* A less clear indication that our client * does not support NFSv4 minor version. */ - if (mi->version.v_mode == V_GENERAL && - mi->version.minor == 0) - return result; if (mi->version.v_mode != V_SPECIFIC) { if (mi->version.minor > 0) { mi->version.minor--; @@ -862,6 +860,9 @@ check_result: /* UDP-Only servers won't support v4, but maybe it * just isn't ready yet. So try v3, but double-check * with rpcbind for v4. */ + if (mi->version.v_mode == V_GENERAL) + /* Mustn't try v2,v3 */ + return result; result = nfs_try_mount_v3v2(mi, TRUE); if (result == 0 && errno == EAGAIN) { /* v4 server seems to be registered now. */ @@ -878,6 +879,9 @@ check_result: } fall_back: + if (mi->version.v_mode == V_GENERAL) + /* v2,3 fallback not allowed */ + return result; return nfs_try_mount_v3v2(mi, FALSE); } |