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From: NeilBrown <neilb@ownmail.net>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>,
	Chuck Lever <cel@kernel.org>, Jeff Layton <jlayton@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: [PATCH 7/7] nfsd: use vfs_lookup_open() for non-creating open requests too.
Date: Thu, 10 Sep 2026 10:20:53 +1000	[thread overview]
Message-ID: <20260910002934.192979-8-neilb@ownmail.net> (raw)
In-Reply-To: <20260910002934.192979-1-neilb@ownmail.net>

From: NeilBrown <neil@brown.name>

Now that we have vfs_lookup_open() for open requests which create, we
can use it for non-creating requests too as vfs_lookup_open() is already
able to do that.  nfsd4_create_file() is renamed to nfsd4_open_file()
and enhanced to not always create, and is then used for all OPEN
requests.

The resulting simplification allows fh_fill_pre_attrs_unlocked() to be
moved into nfsd4_open_file() so it is closer to fh_full_post_attrs and
fh_fill_post_noop calls.

As ->op_create_mode isn't defined when op_create is zero, we need a
local create_mode which is -1 (illegal value) when op_create is zero.

The non-create path now doesn't use nfsd_lookup().  As mount-point
crossing including nfsd_check_access() is already included for existing
names, this does not lose us anything.

Signed-off-by: NeilBrown <neil@brown.name>
---
 fs/nfsd/nfs4proc.c | 109 ++++++++++++++++++++++-----------------------
 1 file changed, 53 insertions(+), 56 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index a6ba7618a307..1f3096486565 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -251,29 +251,30 @@ static inline bool nfsd4_create_is_exclusive(int createmode)
 }
 
 /*
- * Implement NFSv4's unchecked, guarded, and exclusive create
- * semantics for regular files. Open state for this new file is
- * subsequently fabricated in nfsd4_process_open2().
- *
+ * Implement NFSv4's open semantics for regular files.
+ * Both create (unchecked, guarded, and exclusive) and non-create.
+ * Open state for this new file is subsequently fabricated in
+ * nfsd4_process_open2().
  * Upon return, caller must release @fhp and @resfhp.
  */
 static __be32
-nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
-		  struct svc_fh *resfhp, struct nfsd4_open *open)
+nfsd4_open_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct svc_fh *resfhp, struct nfsd4_open *open)
 {
 	struct iattr *iap = &open->op_iattr;
 	struct nfsd_attrs attrs = {
 		.na_iattr	= iap,
 		.na_seclabel	= &open->op_label,
 	};
-	int oflags = O_CREAT | O_LARGEFILE | O_NONBLOCK;
+	int oflags = O_LARGEFILE | O_NONBLOCK;
 	struct dentry *child = ERR_PTR(-EINVAL);
 	struct path parent = {
 		.mnt = fhp->fh_export->ex_path.mnt,
 		.dentry = fhp->fh_dentry,
 	};
 	__u32 v_mtime, v_atime;
-	__be32 status, create_status;
+	int createmode = -1;
+	__be32 status, create_status = 0;
 	int want_write_err;
 
 	if (name_is_dot_dotdot(open->op_fname, open->op_fnamelen))
@@ -285,6 +286,10 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (status != nfs_ok)
 		return status;
 
+	status = fh_fill_pre_attrs_unlocked(fhp);
+	if (status)
+		return status;
+
 	if (open->op_createmode == NFS4_CREATE_UNCHECKED) {
 		/*
 		 * If name is already in dcache we need to check for mountpoints
@@ -315,11 +320,15 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (!IS_POSIXACL(d_inode(parent.dentry)))
 		iap->ia_mode &= ~current_umask();
 
+	if (open->op_create) {
+		createmode = open->op_createmode;
+		oflags |= O_CREAT;
+	}
 	/*
 	 * For the EXCLUSIVE modes we do our own uniqueness tests
 	 * so don't want O_EXCL.
 	 */
-	if (open->op_createmode == NFS4_CREATE_GUARDED)
+	if (createmode == NFS4_CREATE_GUARDED)
 		oflags |= O_EXCL;
 
 	switch (open->op_share_access & NFS4_SHARE_ACCESS_BOTH) {
@@ -351,7 +360,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 	v_mtime = 0;
 	v_atime = 0;
-	if (nfsd4_create_is_exclusive(open->op_createmode)) {
+	if (nfsd4_create_is_exclusive(createmode)) {
 		u32 *verifier = (u32 *)open->op_verf.data;
 
 		/*
@@ -373,11 +382,11 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		iap->ia_atime.tv_nsec = 0;
 	}
 
-	create_status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
-	if (create_status)
-		/* Might still succeed if no create is needed */
-		oflags &= ~O_CREAT;
-
+	if (oflags & O_CREAT) {
+		create_status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+		if (create_status)
+			oflags &= ~O_CREAT;
+	}
 	dget(parent.dentry);
 	open->op_filp = vfs_lookup_open(&parent,
 					&QSTR_LEN(open->op_fname,
@@ -387,7 +396,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (IS_ERR(open->op_filp)) {
 		status = nfserrno(PTR_ERR(open->op_filp));
 		if (status == nfserr_wrong_type) {
-			if (nfsd4_create_is_exclusive(open->op_createmode))
+			if (nfsd4_create_is_exclusive(createmode))
 				status = nfserr_exist;
 			else
 				status = nfsd_check_obj_isreg(parent.dentry);
@@ -409,14 +418,14 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		goto out;
 
 	if (!open->op_created &&
-	    nfsd4_create_is_exclusive(open->op_createmode) &&
+	    nfsd4_create_is_exclusive(createmode) &&
 	    inode_get_mtime_sec(d_inode(child)) == v_mtime &&
 	    inode_get_atime_sec(d_inode(child)) == v_atime &&
 	    d_inode(child)->i_size == 0)
 		open->op_created = true;
 
 	if (!open->op_created) {
-		if (nfsd4_create_is_exclusive(open->op_createmode)) {
+		if (nfsd4_create_is_exclusive(createmode)) {
 			status = nfserr_exist;
 		} else {
 			/* NFSv4 protocol requires change attributes
@@ -512,46 +521,34 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 	fh_init(*resfh, NFS4_FHSIZE);
 	open->op_truncate = false;
 
-	status = fh_fill_pre_attrs_unlocked(current_fh);
-	if (status)
-		goto out;
-	if (open->op_create) {
-		/* FIXME: check session persistence and pnfs flags.
-		 * The nfsv4.1 spec requires the following semantics:
-		 *
-		 * Persistent   | pNFS   | Server REQUIRED | Client Allowed
-		 * Reply Cache  | server |                 |
-		 * -------------+--------+-----------------+--------------------
-		 * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
-		 *              |        |                 | (SHOULD)
-		 *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
-		 *              |        |                 | (SHOULD NOT)
-		 * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
-		 * yes          | no     | GUARDED4        | GUARDED4
-		 * yes          | yes    | GUARDED4        | GUARDED4
-		 */
+	/* FIXME: check session persistence and pnfs flags.
+	 * The nfsv4.1 spec requires the following semantics:
+	 *
+	 * Persistent   | pNFS   | Server REQUIRED | Client Allowed
+	 * Reply Cache  | server |                 |
+	 * -------------+--------+-----------------+--------------------
+	 * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
+	 *              |        |                 | (SHOULD)
+	 *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
+	 *              |        |                 | (SHOULD NOT)
+	 * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
+	 * yes          | no     | GUARDED4        | GUARDED4
+	 * yes          | yes    | GUARDED4        | GUARDED4
+	 */
 
-		current->fs->umask = open->op_umask;
-		status = nfsd4_create_file(rqstp, current_fh, *resfh, open);
-		current->fs->umask = 0;
+	current->fs->umask = open->op_umask;
+	status = nfsd4_open_file(rqstp, current_fh, *resfh, open);
+	current->fs->umask = 0;
 
-		/*
-		 * Following rfc 3530 14.2.16, and rfc 5661 18.16.4
-		 * use the returned bitmask to indicate which attributes
-		 * we used to store the verifier:
-		 */
-		if (nfsd4_create_is_exclusive(open->op_createmode) && status == 0)
-			open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
-						FATTR4_WORD1_TIME_MODIFY);
-	} else {
-		status = nfsd_lookup(rqstp, current_fh,
-				     open->op_fname, open->op_fnamelen, *resfh);
-		/*
-		 * NFSv4 protocol requires change attributes even though
-		 * no change happened.
-		 */
-		fh_fill_post_noop(current_fh);
-	}
+	/*
+	 * Following rfc 3530 14.2.16, and rfc 5661 18.16.4
+	 * use the returned bitmask to indicate which attributes
+	 * we used to store the verifier:
+	 */
+	if (open->op_create &&
+	    nfsd4_create_is_exclusive(open->op_createmode) && status == 0)
+		open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
+				      FATTR4_WORD1_TIME_MODIFY);
 	if (status)
 		goto out;
 	status = nfsd_check_obj_isreg((*resfh)->fh_dentry);
-- 
2.50.0.107.gf914562f5916.dirty


  parent reply	other threads:[~2026-09-10  0:30 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-10  0:20 [PATCH 0/7 RFC] fixes for vfs_lookup_open, and integration with nfsd NeilBrown
2026-09-10  0:20 ` [PATCH 1/7] vfs: add some allowed open flags to vfs_lookup_open() NeilBrown
2026-09-10  0:20 ` [PATCH 2/7] vfs: O_NONBLOCK|O_CREAT open shouldn't wait for directory delegation NeilBrown
2026-09-10  0:20 ` [PATCH 3/7] vfs: vfs_lookup_open() should only return -EFTYPE for non-regular files NeilBrown
2026-09-10  0:20 ` [PATCH 4/7] vfs: change vfs_lookup_open() to return found dentry in path.dentry NeilBrown
2026-09-10  0:39   ` NeilBrown
2026-09-10 15:13   ` Chuck Lever
2026-09-12  2:59     ` NeilBrown
2026-09-10  0:20 ` [PATCH 5/7] nfsd: switch NFS4 OPEN to use vfs_lookup_open() NeilBrown
2026-09-10 15:41   ` Chuck Lever
2026-09-12  3:22     ` NeilBrown
2026-09-10  0:20 ` [PATCH 6/7] nfsd: nfsd_check_obj_isreg() to use nfs error codes NeilBrown
2026-09-10  0:20 ` NeilBrown [this message]
2026-09-10 15:47   ` [PATCH 7/7] nfsd: use vfs_lookup_open() for non-creating open requests too Chuck Lever

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