[PATCH RFC v2 10/28] nfsd: allow filecache to hold S_IFDIR files

[Jeff Layton <jlayton@kernel.org>]

The filecache infrastructure will only handle S_ISREG files at the
moment. Plumb a "type" variable into nfsd_file_do_acquire and have all
of the existing callers set it to S_ISREG. Add a new
nfsd_file_acquire_dir() wrapper that we can then call to request a
nfsd_file that holds a directory open.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfsd/filecache.c | 50 ++++++++++++++++++++++++++++++++++++++------------
 fs/nfsd/filecache.h |  2 ++
 fs/nfsd/vfs.c       |  5 +++--
 fs/nfsd/vfs.h       |  2 +-
 4 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index ab85e6a2454f4c783fcb1175ebbeb63a31519c18..3468883146afc080d2b4862e6002b2c6ff7315b9 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1049,7 +1049,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,
 		     struct auth_domain *client,
 		     struct svc_fh *fhp,
 		     unsigned int may_flags, struct file *file,
-		     struct nfsd_file **pnf, bool want_gc)
+		     umode_t type, bool want_gc, struct nfsd_file **pnf)
 {
 	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
 	struct nfsd_file *new, *nf;
@@ -1060,13 +1060,13 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,
 	int ret;
 
 retry:
-	if (rqstp) {
-		status = fh_verify(rqstp, fhp, S_IFREG,
+	if (rqstp)
+		status = fh_verify(rqstp, fhp, type,
 				   may_flags|NFSD_MAY_OWNER_OVERRIDE);
-	} else {
-		status = fh_verify_local(net, cred, client, fhp, S_IFREG,
+	else
+		status = fh_verify_local(net, cred, client, fhp, type,
 					 may_flags|NFSD_MAY_OWNER_OVERRIDE);
-	}
+
 	if (status != nfs_ok)
 		return status;
 	inode = d_inode(fhp->fh_dentry);
@@ -1147,7 +1147,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,
 			status = nfs_ok;
 			trace_nfsd_file_opened(nf, status);
 		} else {
-			ret = nfsd_open_verified(fhp, may_flags, &nf->nf_file);
+			ret = nfsd_open_verified(fhp, type, may_flags, &nf->nf_file);
 			if (ret == -EOPENSTALE && stale_retry) {
 				stale_retry = false;
 				nfsd_file_unhash(nf);
@@ -1207,7 +1207,7 @@ nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		     unsigned int may_flags, struct nfsd_file **pnf)
 {
 	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
-				    fhp, may_flags, NULL, pnf, true);
+				    fhp, may_flags, NULL, S_IFREG, true, pnf);
 }
 
 /**
@@ -1232,7 +1232,7 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		  unsigned int may_flags, struct nfsd_file **pnf)
 {
 	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
-				    fhp, may_flags, NULL, pnf, false);
+				    fhp, may_flags, NULL, S_IFREG, false, pnf);
 }
 
 /**
@@ -1275,8 +1275,8 @@ nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
 	const struct cred *save_cred = get_current_cred();
 	__be32 beres;
 
-	beres = nfsd_file_do_acquire(NULL, net, cred, client,
-				     fhp, may_flags, NULL, pnf, false);
+	beres = nfsd_file_do_acquire(NULL, net, cred, client, fhp, may_flags,
+				     NULL, S_IFREG, false, pnf);
 	put_cred(revert_creds(save_cred));
 	return beres;
 }
@@ -1305,7 +1305,33 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			 struct nfsd_file **pnf)
 {
 	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
-				    fhp, may_flags, file, pnf, false);
+				    fhp, may_flags, file, S_IFREG, false, pnf);
+}
+
+/**
+ * nfsd_file_acquire_dir - Get a struct nfsd_file with an open directory
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file to be opened
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put(). This opens directories only, and only
+ * in O_RDONLY mode.
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_dir(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		      struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL, fhp,
+				    NFSD_MAY_READ|NFSD_MAY_64BIT_COOKIE,
+				    NULL, S_IFDIR, false, pnf);
 }
 
 /*
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
index 5865f9c7271214de7269ab33480689cd61c1c552..3717503f6b75462c7afca6216d9c915e055b117d 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -78,5 +78,7 @@ __be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
 __be32 nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
 			       struct auth_domain *client, struct svc_fh *fhp,
 			       unsigned int may_flags, struct nfsd_file **pnf);
+__be32 nfsd_file_acquire_dir(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct nfsd_file **pnf);
 int nfsd_file_cache_stats_show(struct seq_file *m, void *v);
 #endif /* _FS_NFSD_FILECACHE_H */
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index cd689df2ca5d7396cffb5ed9dc14f774a8f3881c..86873662925e2f50823d4ce371f1018b749b4c6d 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -949,15 +949,16 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 /**
  * nfsd_open_verified - Open a regular file for the filecache
  * @fhp: NFS filehandle of the file to open
+ * @type: S_IFMT inode type allowed (0 means any type is allowed)
  * @may_flags: internal permission flags
  * @filp: OUT: open "struct file *"
  *
  * Returns zero on success, or a negative errno value.
  */
 int
-nfsd_open_verified(struct svc_fh *fhp, int may_flags, struct file **filp)
+nfsd_open_verified(struct svc_fh *fhp, umode_t type, int may_flags, struct file **filp)
 {
-	return __nfsd_open(fhp, S_IFREG, may_flags, filp);
+	return __nfsd_open(fhp, type, may_flags, filp);
 }
 
 /*
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index eff04959606fe55c141ab4a2eed97c7e0716a5f5..9c309cdee6c491d445d56cdc6133f37248ab4b46 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -114,7 +114,7 @@ __be32		nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 int 		nfsd_open_break_lease(struct inode *, int);
 __be32		nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
 				int, struct file **);
-int		nfsd_open_verified(struct svc_fh *fhp, int may_flags,
+int		nfsd_open_verified(struct svc_fh *fhp, umode_t type, int may_flags,
 				struct file **filp);
 __be32		nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
 				struct file *file, loff_t offset,

-- 
2.49.0