[PATCH v6 14/17] nfsd: allow filecache to hold S_IFDIR files

Jeff Layton
2025-11-11T14:13:52Z

The filecache infrastructure will only handle S_IFREG files at the
moment. Directory delegations will require adding support for opening
S_IFDIR inodes.

Plumb a "type" argument into nfsd_file_do_acquire() and have all of the
existing callers set it to S_IFREG. Add a new nfsd_file_acquire_dir()
wrapper that nfsd can call to request a nfsd_file that holds a directory
open.

For now, there is no need for a fsnotify_mark for directories, as
CB_NOTIFY is not yet supported. Change nfsd_file_do_acquire() to avoid
allocating one for non-S_IFREG inodes.

Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/nfsd/filecache.c | 57 ++++++++++++++++++++++++++++++++++++++++-------------
fs/nfsd/filecache.h | 2 ++
fs/nfsd/vfs.c | 5 +++--
fs/nfsd/vfs.h | 2 +-
4 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index a238b6725008a5c2988bd3da874d1f34ee778437..93798575b8075c63f95cd415b6d24df706ada0f6 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1086,7 +1086,7 @@ 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;
@@ -1097,13 +1097,13 @@ 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);
@@ -1176,15 +1176,18 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,

open_file:
trace_nfsd_file_alloc(nf);
- nf->nf_mark = nfsd_file_mark_find_or_create(inode);
- if (nf->nf_mark) {
+
+ if (type == S_IFREG)
+ nf->nf_mark = nfsd_file_mark_find_or_create(inode);
+
+ if (type != S_IFREG || nf->nf_mark) {
if (file) {
get_file(file);
nf->nf_file = file;
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);
@@ -1246,7 +1249,7 @@ 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);
}

/**
@@ -1271,7 +1274,7 @@ 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);
}

/**
@@ -1314,8 +1317,8 @@ 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;
}
@@ -1344,7 +1347,33 @@ 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 e3d6ca2b60308e5e91ba4bb32d935f54527d8bda..b383dbc5b9218d21a29b852572f80fab08de9fa9 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -82,5 +82,7 @@ __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 28710da4cce7cc7fc1e14d29420239dc357316f6..8c3ffacc533e9de0d506fb2ec222387446ba8e9f 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -959,15 +959,16 @@ 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 0c0292611c6de3daf6f3ed51e2c61c0ad2751de4..09de48c50cbef8e7c4828b38dcb663b529514a30 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,

--
2.51.1