git: 529957726679 - stable/13 - nfsd: Fix the NFSv4 pNFS MDS server for DS NFSERR_NOSPC

The branch stable/13 has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=5299577266790d1da58db29ada5082550287ce55

commit 5299577266790d1da58db29ada5082550287ce55
Author:     Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2021-11-07 19:43:03 +0000
Commit:     Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2021-11-21 15:59:49 +0000

    nfsd: Fix the NFSv4 pNFS MDS server for DS NFSERR_NOSPC
    
    If a pNFS server's DS runs out of disk space, it replies
    NFSERR_NOSPC to the client doing writing.  For the Linux
    client, it then sends a LayoutError RPC to the server to
    tell it about the error and keeps retrying, doing repeated
    LayoutGet and Write RPCs to the DS.  The Linux client is
    "stuck" until disk space on the DS is free'd up.
    For a mirrored server configuration, the first mirror that
    ran out of space was taken offline.  This does not make
    much sense, since the other mirror(s) will run out of space
    soon and the fix is a manual cleanup up disk space.
    
    This patch changes the pNFS server to not disable a mirror
    for the mirrored case when this occurs.
    
    Further work is needed, since the Linux client expects the
    MDS to reply NFSERR_NOSPC to LayoutGets once the DS is out
    of space.  Without this further change, the above mentioned
    looping occurs.
    
    Found during a recent IEFT NFSv4 working group testing event.
    
    (cherry picked from commit a7e014eee5d47d6eb13bc98c71e65d00a6de8ed3)
---
 sys/fs/nfsserver/nfs_nfsdserv.c  | 7 ++++---
 sys/fs/nfsserver/nfs_nfsdstate.c | 7 ++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/sys/fs/nfsserver/nfs_nfsdserv.c b/sys/fs/nfsserver/nfs_nfsdserv.c
index 7ca766c99069..0e447778d639 100644
--- a/sys/fs/nfsserver/nfs_nfsdserv.c
+++ b/sys/fs/nfsserver/nfs_nfsdserv.c
@@ -5046,10 +5046,11 @@ nfsrvd_layouterror(struct nfsrv_descript *nd, __unused int isdgram,
 		opnum = fxdr_unsigned(int, *tl);
 		NFSD_DEBUG(4, "nfsrvd_layouterr op=%d stat=%d\n", opnum, stat);
 		/*
-		 * Except for NFSERR_ACCES and NFSERR_STALE errors,
-		 * disable the mirror.
+		 * Except for NFSERR_ACCES, NFSERR_STALE and NFSERR_NOSPC
+		 * errors, disable the mirror.
 		 */
-		if (stat != NFSERR_ACCES && stat != NFSERR_STALE)
+		if (stat != NFSERR_ACCES && stat != NFSERR_STALE &&
+		    stat != NFSERR_NOSPC)
 			nfsrv_delds(devid, curthread);
 	}
 nfsmout:
diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c
index 750eda2027ec..797b9b0a466e 100644
--- a/sys/fs/nfsserver/nfs_nfsdstate.c
+++ b/sys/fs/nfsserver/nfs_nfsdstate.c
@@ -7009,10 +7009,11 @@ nfsrv_flexlayouterr(struct nfsrv_descript *nd, uint32_t *layp, int maxcnt,
 			NFSD_DEBUG(4, "flexlayouterr op=%d stat=%d\n", opnum,
 			    stat);
 			/*
-			 * Except for NFSERR_ACCES and NFSERR_STALE errors,
-			 * disable the mirror.
+			 * Except for NFSERR_ACCES, NFSERR_STALE and
+			 * NFSERR_NOSPC errors, disable the mirror.
 			 */
-			if (stat != NFSERR_ACCES && stat != NFSERR_STALE)
+			if (stat != NFSERR_ACCES && stat != NFSERR_STALE &&
+			    stat != NFSERR_NOSPC)
 				nfsrv_delds(devid, p);
 		}
 	}