All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chuck Lever <chuck.lever@oracle.com>
To: linux-nfs@vger.kernel.org
Cc: trondmy@hammerspace.com, bfields@fieldses.org,
	jlayton@redhat.com, dai.ngo@oracle.com
Subject: [PATCH RFC 1/2] NFSD: nfsd4_release_lockowner() should drop clp->cl_lock sooner
Date: Wed, 11 May 2022 17:52:51 -0400	[thread overview]
Message-ID: <165230597191.5906.5961060184718742042.stgit@klimt.1015granger.net> (raw)
In-Reply-To: <165230584037.5906.5496655737644872339.stgit@klimt.1015granger.net>

nfsd4_release_lockowner() mustn't hold clp->cl_lock when
check_for_locks() invokes nfsd_file_put(), which can sleep.

Reported-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
---
 fs/nfsd/nfs4state.c |   56 +++++++++++++++++++++++----------------------------
 1 file changed, 25 insertions(+), 31 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 234e852fcdfa..e2eb6d031643 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -6611,8 +6611,8 @@ nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
 		deny->ld_type = NFS4_WRITE_LT;
 }
 
-static struct nfs4_lockowner *
-find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
+static struct nfs4_stateowner *
+find_stateowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
 {
 	unsigned int strhashval = ownerstr_hashval(owner);
 	struct nfs4_stateowner *so;
@@ -6624,11 +6624,22 @@ find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
 		if (so->so_is_open_owner)
 			continue;
 		if (same_owner_str(so, owner))
-			return lockowner(nfs4_get_stateowner(so));
+			return nfs4_get_stateowner(so);
 	}
 	return NULL;
 }
 
+static struct nfs4_lockowner *
+find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
+{
+	struct nfs4_stateowner *so;
+
+	so = find_stateowner_str_locked(clp, owner);
+	if (!so)
+		return NULL;
+	return lockowner(so);
+}
+
 static struct nfs4_lockowner *
 find_lockowner_str(struct nfs4_client *clp, struct xdr_netobj *owner)
 {
@@ -7305,10 +7316,8 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
 	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
 	clientid_t *clid = &rlockowner->rl_clientid;
 	struct nfs4_stateowner *sop;
-	struct nfs4_lockowner *lo = NULL;
+	struct nfs4_lockowner *lo;
 	struct nfs4_ol_stateid *stp;
-	struct xdr_netobj *owner = &rlockowner->rl_owner;
-	unsigned int hashval = ownerstr_hashval(owner);
 	__be32 status;
 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 	struct nfs4_client *clp;
@@ -7322,32 +7331,18 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
 		return status;
 
 	clp = cstate->clp;
-	/* Find the matching lock stateowner */
 	spin_lock(&clp->cl_lock);
-	list_for_each_entry(sop, &clp->cl_ownerstr_hashtbl[hashval],
-			    so_strhash) {
-
-		if (sop->so_is_open_owner || !same_owner_str(sop, owner))
-			continue;
-
-		/* see if there are still any locks associated with it */
-		lo = lockowner(sop);
-		list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) {
-			if (check_for_locks(stp->st_stid.sc_file, lo)) {
-				status = nfserr_locks_held;
-				spin_unlock(&clp->cl_lock);
-				return status;
-			}
-		}
+	sop = find_stateowner_str_locked(clp, &rlockowner->rl_owner);
+	spin_unlock(&clp->cl_lock);
+	if (!sop)
+		return nfs_ok;
 
-		nfs4_get_stateowner(sop);
-		break;
-	}
-	if (!lo) {
-		spin_unlock(&clp->cl_lock);
-		return status;
-	}
+	lo = lockowner(sop);
+	list_for_each_entry(stp, &sop->so_stateids, st_perstateowner)
+		if (check_for_locks(stp->st_stid.sc_file, lo))
+			return nfserr_locks_held;
 
+	spin_lock(&clp->cl_lock);
 	unhash_lockowner_locked(lo);
 	while (!list_empty(&lo->lo_owner.so_stateids)) {
 		stp = list_first_entry(&lo->lo_owner.so_stateids,
@@ -7360,8 +7355,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
 	free_ol_stateid_reaplist(&reaplist);
 	remove_blocked_locks(lo);
 	nfs4_put_stateowner(&lo->lo_owner);
-
-	return status;
+	return nfs_ok;
 }
 
 static inline struct nfs4_client_reclaim *



  reply	other threads:[~2022-05-11 21:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-11 21:52 [PATCH RFC 0/2] Fix "sleep while locked" in RELEASE_LOCKOWNER Chuck Lever
2022-05-11 21:52 ` Chuck Lever [this message]
2022-05-11 22:04   ` [PATCH RFC 1/2] NFSD: nfsd4_release_lockowner() should drop clp->cl_lock sooner Trond Myklebust
2022-05-12 14:03     ` Chuck Lever III
2022-05-12 10:07   ` Jeff Layton
2022-05-12 14:10     ` Chuck Lever III
2022-05-11 21:52 ` [PATCH RFC 2/2] NFSD: nfsd_file_put() can sleep Chuck Lever
2022-05-12 10:08   ` Jeff Layton
     [not found] ` <PH0PR14MB549335582C7A4D4F4D2269B2AAD99@PH0PR14MB5493.namprd14.prod.outlook.com>
2022-05-26 23:39   ` [PATCH RFC 0/2] Fix "sleep while locked" in RELEASE_LOCKOWNER Chuck Lever III
2022-05-27  0:21     ` Charles Hedrick
2022-05-27 15:32       ` Chuck Lever III

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=165230597191.5906.5961060184718742042.stgit@klimt.1015granger.net \
    --to=chuck.lever@oracle.com \
    --cc=bfields@fieldses.org \
    --cc=dai.ngo@oracle.com \
    --cc=jlayton@redhat.com \
    --cc=linux-nfs@vger.kernel.org \
    --cc=trondmy@hammerspace.com \
    --subject='Re: [PATCH RFC 1/2] NFSD: nfsd4_release_lockowner() should drop clp->cl_lock sooner' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.