[PATCH 5.16 0671/1017] NFS: Return valid errors from nfs2/3_decode_dirent()

Greg Kroah-Hartman
2022-04-05T10:17:56Z

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

[ Upstream commit 64cfca85bacde54caa64e0ab855c48734894fa37 ]

Valid return values for decode_dirent() callback functions are:
0: Success
-EBADCOOKIE: End of directory
-EAGAIN: End of xdr_stream

All errors need to map into one of those three values.

Fixes: 573c4e1ef53a ("NFS: Simplify ->decode_dirent() calling sequence")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs2xdr.c | 2 +-
fs/nfs/nfs3xdr.c | 21 ++++++---------------
2 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 7fba7711e6b3..3d5ba43f44bb 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -949,7 +949,7 @@ int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,

error = decode_filename_inline(xdr, &entry->name, &entry->len);
if (unlikely(error))
- return error;
+ return -EAGAIN;

/*
* The type (size and byte order) of nfscookie isn't defined in
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 54a1d21cbcc6..7ab60ad98776 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -1967,7 +1967,6 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
bool plus)
{
struct user_namespace *userns = rpc_userns(entry->server->client);
- struct nfs_entry old = *entry;
__be32 *p;
int error;
u64 new_cookie;
@@ -1987,15 +1986,15 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,

error = decode_fileid3(xdr, &entry->ino);
if (unlikely(error))
- return error;
+ return -EAGAIN;

error = decode_inline_filename3(xdr, &entry->name, &entry->len);
if (unlikely(error))
- return error;
+ return -EAGAIN;

error = decode_cookie3(xdr, &new_cookie);
if (unlikely(error))
- return error;
+ return -EAGAIN;

entry->d_type = DT_UNKNOWN;

@@ -2003,7 +2002,7 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
entry->fattr->valid = 0;
error = decode_post_op_attr(xdr, entry->fattr, userns);
if (unlikely(error))
- return error;
+ return -EAGAIN;
if (entry->fattr->valid & NFS_ATTR_FATTR_V3)
entry->d_type = nfs_umode_to_dtype(entry->fattr->mode);

@@ -2018,11 +2017,8 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
return -EAGAIN;
if (*p != xdr_zero) {
error = decode_nfs_fh3(xdr, entry->fh);
- if (unlikely(error)) {
- if (error == -E2BIG)
- goto out_truncated;
- return error;
- }
+ if (unlikely(error))
+ return -EAGAIN;
} else
zero_nfs_fh3(entry->fh);
}
@@ -2031,11 +2027,6 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
entry->cookie = new_cookie;

return 0;
-
-out_truncated:
- dprintk("NFS: directory entry contains invalid file handle\n");
- *entry = old;
- return -EAGAIN;
}

/*
--
2.34.1