git: 8a04edfdcbd2 - stable/13 - nfscl: Change the default minor version for NFSv4 mounts

[Rick Macklem]

The branch stable/13 has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=8a04edfdcbd2267ce8d8485374101bba580f5d83

commit 8a04edfdcbd2267ce8d8485374101bba580f5d83
Author:     Rick Macklem <rmacklem at FreeBSD.org>
AuthorDate: 2021-06-25 01:52:23 +0000
Commit:     Rick Macklem <rmacklem at FreeBSD.org>
CommitDate: 2021-07-11 22:26:55 +0000

    nfscl: Change the default minor version for NFSv4 mounts
    
    When NFSv4.1 support was added to the client, the implementation was
    still experimental and, as such, the default minor version was set to 0.
    Since the NFSv4.1 client implementation is now believed to be solid
    and the NFSv4.1/4.2 protocol is significantly better than NFSv4.0,
    I beieve that NFSv4.1/4.2 should be used where possible.
    
    This patch changes the default minor version for NFSv4 to be the highest
    minor version supported by the NFSv4 server. If a specific minor version
    is desired, the "minorversion" mount option can be used to override
    this default.  This is compatible with the Linux NFSv4 client behaviour.
    
    This was discussed on freebsd-current@ in mid-May 2021 under
    the subject "changing the default NFSv4 minor version" and
    the consensus seemed to be support for this change.
    It also appeared that changing this for FreeBSD 13.1 was
    not considered a POLA violation, so long as UPDATING
    and RELNOTES entries were made for it.
    
    (cherry picked from commit a145cf3f73c7d0f6071a6bddbe8a50a280285900)
---
 sys/fs/nfsclient/nfs_clstate.c  |  9 ++++++++-
 sys/fs/nfsclient/nfs_clvfsops.c | 14 ++++++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c
index fb90c80c69e7..8ea5d77d2053 100644
--- a/sys/fs/nfsclient/nfs_clstate.c
+++ b/sys/fs/nfsclient/nfs_clstate.c
@@ -959,11 +959,18 @@ nfscl_getcl(struct mount *mp, struct ucred *cred, NFSPROC_T *p,
 			    error == NFSERR_BADSESSION ||
 			    error == NFSERR_CLIDINUSE) {
 				(void) nfs_catnap(PZERO, error, "nfs_setcl");
+			} else if (error == NFSERR_MINORVERMISMATCH &&
+			    tryminvers) {
+				if (nmp->nm_minorvers > 0)
+					nmp->nm_minorvers--;
+				else
+					tryminvers = false;
 			}
 		} while (((error == NFSERR_STALECLIENTID ||
 		     error == NFSERR_BADSESSION ||
 		     error == NFSERR_STALEDONTRECOVER) && --trystalecnt > 0) ||
-		    (error == NFSERR_CLIDINUSE && --clidinusedelay > 0));
+		    (error == NFSERR_CLIDINUSE && --clidinusedelay > 0) ||
+		    (error == NFSERR_MINORVERMISMATCH && tryminvers));
 		if (error) {
 			NFSLOCKCLSTATE();
 			nfsv4_unlock(&clp->nfsc_lock, 0);
diff --git a/sys/fs/nfsclient/nfs_clvfsops.c b/sys/fs/nfsclient/nfs_clvfsops.c
index 5abd41dee1a1..974bc684bf5b 100644
--- a/sys/fs/nfsclient/nfs_clvfsops.c
+++ b/sys/fs/nfsclient/nfs_clvfsops.c
@@ -895,7 +895,7 @@ nfs_mount(struct mount *mp)
 	char *cp, *opt, *name, *secname, *tlscertname;
 	int nametimeo = NFS_DEFAULT_NAMETIMEO;
 	int negnametimeo = NFS_DEFAULT_NEGNAMETIMEO;
-	int minvers = 0;
+	int minvers = -1;
 	int dirlen, has_nfs_args_opt, has_nfs_from_opt,
 	    krbnamelen, srvkrbnamelen;
 	size_t hstlen;
@@ -1417,6 +1417,7 @@ mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
 	struct nfsclclient *clp;
 	struct nfsclds *dsp, *tdsp;
 	uint32_t lease;
+	bool tryminvers;
 	static u_int64_t clval = 0;
 #ifdef KERN_TLS
 	u_int maxlen;
@@ -1521,9 +1522,14 @@ mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
 		nmp->nm_wcommitsize *= 2;
 	nmp->nm_wcommitsize *= 256;
 
-	if ((argp->flags & NFSMNT_NFSV4) != 0)
+	tryminvers = false;
+	if ((argp->flags & NFSMNT_NFSV4) != 0) {
+		if (minvers < 0) {
+			tryminvers = true;
+			minvers = NFSV42_MINORVERSION;
+		}
 		nmp->nm_minorvers = minvers;
-	else
+	} else
 		nmp->nm_minorvers = 0;
 
 	nfs_decode_args(mp, nmp, argp, hst, cred, td);
@@ -1574,7 +1580,7 @@ mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
 	/* For NFSv4, get the clientid now. */
 	if ((argp->flags & NFSMNT_NFSV4) != 0) {
 		NFSCL_DEBUG(3, "at getcl\n");
-		error = nfscl_getcl(mp, cred, td, false, &clp);
+		error = nfscl_getcl(mp, cred, td, tryminvers, &clp);
 		NFSCL_DEBUG(3, "aft getcl=%d\n", error);
 		if (error != 0)
 			goto bad;