git: 81c9491a5b4c - stable/12 - nfscl: Fix two more cases for forced dismount

The branch stable/12 has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=81c9491a5b4c81e50e88967a977c8674fd580f25

commit 81c9491a5b4c81e50e88967a977c8674fd580f25
Author:     Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2021-11-05 22:33:19 +0000
Commit:     Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2021-11-19 22:39:56 +0000

    nfscl: Fix two more cases for forced dismount
    
    Although I was not able to cause a failure during testing, there
    are places in nfscl_removedeleg() and nfscl_renamedeleg() where
    I think a forced dismount could get hung.  This patch fixes those.
    
    This patch only affects forced dismount and only if the NFSv4
    server is issuing delegations to the client.
    
    Found by code inspection.
    
    (cherry picked from commit f5d5164fb607ab9c51c52ace4ec241f6cac7cc5c)
---
 sys/fs/nfsclient/nfs_clstate.c | 54 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 46 insertions(+), 8 deletions(-)

diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c
index 387d043b4dbd..c7b9608da1ba 100644
--- a/sys/fs/nfsclient/nfs_clstate.c
+++ b/sys/fs/nfsclient/nfs_clstate.c
@@ -4538,6 +4538,7 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp)
 	struct nfsclowner *owp;
 	struct nfscllockowner *lp;
 	struct nfsmount *nmp;
+	struct mount *mp;
 	struct ucred *cred;
 	struct nfsnode *np;
 	int igotlock = 0, triedrecall = 0, needsrecall, retcnt = 0, islept;
@@ -4546,6 +4547,7 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp)
 	if (NFSHASPNFS(nmp))
 		return (retcnt);
 	np = VTONFS(vp);
+	mp = nmp->nm_mountp;
 	NFSLOCKCLSTATE();
 	/*
 	 * Loop around waiting for:
@@ -4572,8 +4574,13 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp)
 			    igotlock = 0;
 			}
 			dp->nfsdl_rwlock.nfslock_lock |= NFSV4LOCK_WANTED;
-			(void) nfsmsleep(&dp->nfsdl_rwlock,
-			    NFSCLSTATEMUTEXPTR, PZERO, "nfscld", NULL);
+			msleep(&dp->nfsdl_rwlock, NFSCLSTATEMUTEXPTR, PZERO,
+			    "nfscld", hz);
+			if (NFSCL_FORCEDISM(mp)) {
+			    dp->nfsdl_flags &= ~NFSCLDL_DELEGRET;
+			    NFSUNLOCKCLSTATE();
+			    return (0);
+			}
 			continue;
 		    }
 		    needsrecall = 0;
@@ -4596,7 +4603,14 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp)
 			islept = 0;
 			while (!igotlock) {
 			    igotlock = nfsv4_lock(&clp->nfsc_lock, 1,
-				&islept, NFSCLSTATEMUTEXPTR, NULL);
+				&islept, NFSCLSTATEMUTEXPTR, mp);
+			    if (NFSCL_FORCEDISM(mp)) {
+				dp->nfsdl_flags &= ~NFSCLDL_DELEGRET;
+				if (igotlock)
+				    nfsv4_unlock(&clp->nfsc_lock, 0);
+				NFSUNLOCKCLSTATE();
+				return (0);
+			    }
 			    if (islept)
 				break;
 			}
@@ -4637,6 +4651,7 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 	struct nfsclowner *owp;
 	struct nfscllockowner *lp;
 	struct nfsmount *nmp;
+	struct mount *mp;
 	struct ucred *cred;
 	struct nfsnode *np;
 	int igotlock = 0, triedrecall = 0, needsrecall, retcnt = 0, islept;
@@ -4646,6 +4661,7 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 	*gottdp = 0;
 	if (NFSHASPNFS(nmp))
 		return (retcnt);
+	mp = nmp->nm_mountp;
 	NFSLOCKCLSTATE();
 	/*
 	 * Loop around waiting for:
@@ -4673,8 +4689,15 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 			    igotlock = 0;
 			}
 			dp->nfsdl_rwlock.nfslock_lock |= NFSV4LOCK_WANTED;
-			(void) nfsmsleep(&dp->nfsdl_rwlock,
-			    NFSCLSTATEMUTEXPTR, PZERO, "nfscld", NULL);
+			msleep(&dp->nfsdl_rwlock, NFSCLSTATEMUTEXPTR, PZERO,
+			    "nfscld", hz);
+			if (NFSCL_FORCEDISM(mp)) {
+			    dp->nfsdl_flags &= ~NFSCLDL_DELEGRET;
+			    NFSUNLOCKCLSTATE();
+			    *gotfdp = 0;
+			    *gottdp = 0;
+			    return (0);
+			}
 			continue;
 		    }
 		    needsrecall = 0;
@@ -4697,7 +4720,16 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 			islept = 0;
 			while (!igotlock) {
 			    igotlock = nfsv4_lock(&clp->nfsc_lock, 1,
-				&islept, NFSCLSTATEMUTEXPTR, NULL);
+				&islept, NFSCLSTATEMUTEXPTR, mp);
+			    if (NFSCL_FORCEDISM(mp)) {
+				dp->nfsdl_flags &= ~NFSCLDL_DELEGRET;
+				if (igotlock)
+				    nfsv4_unlock(&clp->nfsc_lock, 0);
+				NFSUNLOCKCLSTATE();
+				*gotfdp = 0;
+				*gottdp = 0;
+				return (0);
+			    }
 			    if (islept)
 				break;
 			}
@@ -4734,8 +4766,14 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 			 */
 			if (dp->nfsdl_rwlock.nfslock_usecnt > 0) {
 			    dp->nfsdl_rwlock.nfslock_lock |= NFSV4LOCK_WANTED;
-			    (void) nfsmsleep(&dp->nfsdl_rwlock,
-				NFSCLSTATEMUTEXPTR, PZERO, "nfscld", NULL);
+			    msleep(&dp->nfsdl_rwlock, NFSCLSTATEMUTEXPTR, PZERO,
+				"nfscld", hz);
+			    if (NFSCL_FORCEDISM(mp)) {
+				NFSUNLOCKCLSTATE();
+				*gotfdp = 0;
+				*gottdp = 0;
+				return (0);
+			    }
 			    continue;
 			}
 			LIST_FOREACH(owp, &dp->nfsdl_owner, nfsow_list) {