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From: trondmy@kernel.org
To: Chuck Lever <chuck.lever@oracle.com>,
	"J. Bruce Fields" <bfields@redhat.com>
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH v2 04/10] nfsd: Distinguish between required and optional NFSv3 post-op attributes
Date: Sat, 18 Dec 2021 20:37:57 -0500	[thread overview]
Message-ID: <20211219013803.324724-5-trondmy@kernel.org> (raw)
In-Reply-To: <20211219013803.324724-4-trondmy@kernel.org>

From: Trond Myklebust <trond.myklebust@primarydata.com>

The fhp->fh_no_wcc flag is automatically set in nfsd_set_fh_dentry()
when the EXPORT_OP_NOWCC flag is set. In svcxdr_encode_post_op_attr(),
this then causes nfsd to skip returning the post-op attributes.

The problem is that some of these post-op attributes are not really
optional. In particular, we do want LOOKUP to always return post-op
attributes for the file that is being looked up.

The solution is therefore to explicitly label the attributes that we can
safely opt out from, and only apply the 'fhp->fh_no_wcc' test in that
case.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfsd/nfs3xdr.c | 77 +++++++++++++++++++++++++++++++----------------
 1 file changed, 51 insertions(+), 26 deletions(-)

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index c3ac1b6aa3aa..6adfc40722fa 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -415,19 +415,9 @@ svcxdr_encode_pre_op_attr(struct xdr_stream *xdr, const struct svc_fh *fhp)
 	return svcxdr_encode_wcc_attr(xdr, fhp);
 }
 
-/**
- * svcxdr_encode_post_op_attr - Encode NFSv3 post-op attributes
- * @rqstp: Context of a completed RPC transaction
- * @xdr: XDR stream
- * @fhp: File handle to encode
- *
- * Return values:
- *   %false: Send buffer space was exhausted
- *   %true: Success
- */
-bool
-svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
-			   const struct svc_fh *fhp)
+static bool
+__svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			     const struct svc_fh *fhp, bool force)
 {
 	struct dentry *dentry = fhp->fh_dentry;
 	struct kstat stat;
@@ -437,7 +427,7 @@ svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	 * stale file handle. In this case, no attributes are
 	 * returned.
 	 */
-	if (fhp->fh_no_wcc || !dentry || !d_really_is_positive(dentry))
+	if (!force || !dentry || !d_really_is_positive(dentry))
 		goto no_post_op_attrs;
 	if (fh_getattr(fhp, &stat) != nfs_ok)
 		goto no_post_op_attrs;
@@ -454,6 +444,31 @@ svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	return xdr_stream_encode_item_absent(xdr) > 0;
 }
 
+/**
+ * svcxdr_encode_post_op_attr - Encode NFSv3 post-op attributes
+ * @rqstp: Context of a completed RPC transaction
+ * @xdr: XDR stream
+ * @fhp: File handle to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
+svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			   const struct svc_fh *fhp)
+{
+	return __svcxdr_encode_post_op_attr(rqstp, xdr, fhp, true);
+}
+
+static bool
+svcxdr_encode_post_op_attr_opportunistic(struct svc_rqst *rqstp,
+					 struct xdr_stream *xdr,
+					 const struct svc_fh *fhp)
+{
+	return __svcxdr_encode_post_op_attr(rqstp, xdr, fhp, !fhp->fh_no_wcc);
+}
+
 /*
  * Encode weak cache consistency data
  */
@@ -481,7 +496,7 @@ svcxdr_encode_wcc_data(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 neither:
 	if (xdr_stream_encode_item_absent(xdr) < 0)
 		return false;
-	if (!svcxdr_encode_post_op_attr(rqstp, xdr, fhp))
+	if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr, fhp))
 		return false;
 
 	return true;
@@ -854,11 +869,13 @@ nfs3svc_encode_lookupres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 			return false;
 		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
 			return false;
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->dirfh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->dirfh))
 			return false;
 		break;
 	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->dirfh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->dirfh))
 			return false;
 	}
 
@@ -875,13 +892,15 @@ nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 		return false;
 	switch (resp->status) {
 	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 		if (xdr_stream_encode_u32(xdr, resp->access) < 0)
 			return false;
 		break;
 	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 	}
 
@@ -899,7 +918,8 @@ nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 		return false;
 	switch (resp->status) {
 	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
 			return false;
@@ -908,7 +928,8 @@ nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 			return false;
 		break;
 	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 	}
 
@@ -926,7 +947,8 @@ nfs3svc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 		return false;
 	switch (resp->status) {
 	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
 			return false;
@@ -940,7 +962,8 @@ nfs3svc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 			return false;
 		break;
 	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 	}
 
@@ -1032,7 +1055,8 @@ nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 		return false;
 	switch (resp->status) {
 	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 		if (!svcxdr_encode_cookieverf3(xdr, resp->verf))
 			return false;
@@ -1044,7 +1068,8 @@ nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 			return false;
 		break;
 	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+		if (!svcxdr_encode_post_op_attr_opportunistic(rqstp, xdr,
+							      &resp->fh))
 			return false;
 	}
 
@@ -1188,7 +1213,7 @@ svcxdr_encode_entry3_plus(struct nfsd3_readdirres *resp, const char *name,
 	if (compose_entry_fh(resp, fhp, name, namlen, ino) != nfs_ok)
 		goto out_noattrs;
 
-	if (!svcxdr_encode_post_op_attr(resp->rqstp, xdr, fhp))
+	if (!svcxdr_encode_post_op_attr_opportunistic(resp->rqstp, xdr, fhp))
 		goto out;
 	if (!svcxdr_encode_post_op_fh3(xdr, fhp))
 		goto out;
-- 
2.33.1


  reply	other threads:[~2021-12-19  1:44 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-19  1:37 [PATCH v2 00/10] Assorted patches for knfsd trondmy
2021-12-19  1:37 ` [PATCH v2 01/10] nfsd: map EBADF trondmy
2021-12-19  1:37   ` [PATCH v2 02/10] nfsd: Add errno mapping for EREMOTEIO trondmy
2021-12-19  1:37     ` [PATCH v2 03/10] nfsd: Retry once in nfsd_open on an -EOPENSTALE return trondmy
2021-12-19  1:37       ` trondmy [this message]
2021-12-19  1:37         ` [PATCH v2 05/10] nfs: Add export support for weak cache consistency attributes trondmy
2021-12-19  1:37           ` [PATCH v2 06/10] nfsd: NFSv3 should allow zero length writes trondmy
2021-12-19  1:38             ` [PATCH v2 07/10] nfsd: Add a tracepoint for errors in nfsd4_clone_file_range() trondmy
2021-12-19  1:38               ` [PATCH v2 08/10] nfsd: Replace use of rwsem with errseq_t trondmy
2021-12-19  1:38                 ` [PATCH v2 09/10] nfsd: allow lockd to be forcibly disabled trondmy
2021-12-19  1:38                   ` [PATCH v2 10/10] nfsd: Ignore rpcbind errors on nfsd startup trondmy
2021-12-19 18:15                     ` Chuck Lever III
2021-12-19 20:49                       ` Trond Myklebust
2021-12-20 15:51                         ` Chuck Lever III
2021-12-20 18:35                           ` Trond Myklebust
2021-12-20 19:02                             ` Chuck Lever III
2021-12-20 19:52                               ` Trond Myklebust
2021-12-20 20:12                                 ` Chuck Lever III
2021-12-19 18:34                   ` [PATCH v2 09/10] nfsd: allow lockd to be forcibly disabled Chuck Lever III
2021-12-21 18:14               ` [PATCH v2 07/10] nfsd: Add a tracepoint for errors in nfsd4_clone_file_range() Chuck Lever III
2021-12-19 20:11             ` [PATCH v2 06/10] nfsd: NFSv3 should allow zero length writes Chuck Lever III
2022-01-05 16:10           ` [PATCH v2 05/10] nfs: Add export support for weak cache consistency attributes Daire Byrne
2021-12-19 20:10         ` [PATCH v2 04/10] nfsd: Distinguish between required and optional NFSv3 post-op attributes Chuck Lever III
2021-12-19 21:09           ` Trond Myklebust
2021-12-20 16:02             ` Chuck Lever III
2021-12-20 18:38               ` Trond Myklebust
2021-12-20 19:22                 ` Chuck Lever III
2021-12-21 18:10 ` [PATCH v2 00/10] Assorted patches for knfsd Chuck Lever III

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