[PATCH RFC 10/24] 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 | 37 +++++++++++++++++++++++++++++++------
 fs/nfsd/filecache.h |  2 ++
 fs/nfsd/vfs.c       |  5 +++--
 fs/nfsd/vfs.h       |  2 +-
 4 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index ddd3e0d9cfa6..ba66d571d567 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -979,7 +979,7 @@ nfsd_file_is_cached(struct inode *inode)
 static __be32
 nfsd_file_do_acquire(struct svc_rqst *rqstp, 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 net *net = SVC_NET(rqstp);
@@ -991,7 +991,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	int ret;
 
 retry:
-	status = fh_verify(rqstp, fhp, S_IFREG,
+	status = fh_verify(rqstp, fhp, type,
 				may_flags|NFSD_MAY_OWNER_OVERRIDE);
 	if (status != nfs_ok)
 		return status;
@@ -1083,7 +1083,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			trace_nfsd_file_opened(nf, status);
 		} else {
 			ret = nfsd_open_verified(rqstp, fhp, may_flags,
-						 &nf->nf_file);
+						 type, &nf->nf_file);
 			if (ret == -EOPENSTALE && stale_retry) {
 				stale_retry = false;
 				nfsd_file_unhash(nf);
@@ -1139,7 +1139,7 @@ __be32
 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, fhp, may_flags, NULL, pnf, true);
+	return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, S_IFREG, true, pnf);
 }
 
 /**
@@ -1163,7 +1163,7 @@ __be32
 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, fhp, may_flags, NULL, pnf, false);
+	return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, S_IFREG, false, pnf);
 }
 
 /**
@@ -1189,7 +1189,32 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			 unsigned int may_flags, struct file *file,
 			 struct nfsd_file **pnf)
 {
-	return nfsd_file_do_acquire(rqstp, fhp, may_flags, file, pnf, false);
+	return nfsd_file_do_acquire(rqstp, 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, 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 c61884def906..de29a1c9d949 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -65,5 +65,7 @@ __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 __be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		  unsigned int may_flags, struct file *file,
 		  struct nfsd_file **nfp);
+__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 fe088e7c49c8..a8313bba2a6f 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -950,6 +950,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
  * nfsd_open_verified - Open a regular file for the filecache
  * @rqstp: RPC request
  * @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 *"
  *
@@ -957,9 +958,9 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
  */
 int
 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
-		   struct file **filp)
+		   umode_t type, struct file **filp)
 {
-	return __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
+	return __nfsd_open(rqstp, fhp, type, may_flags, filp);
 }
 
 /*
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index c60fdb6200fd..c7f0349c179e 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -105,7 +105,7 @@ 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_rqst *rqstp, struct svc_fh *fhp,
-				   int may_flags, struct file **filp);
+				   int may_flags, umode_t type, struct file **filp);
 __be32		nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
 				struct file *file, loff_t offset,
 				unsigned long *count,

-- 
2.44.0