From 6e45906a0b8098937667ddf8fa3b07d916165688 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sun, 26 Jan 2025 16:50:20 -0500 Subject: [PATCH] NFSD: Return NFS4ERR_FILE_OPEN only when linking an open file RFC 8881 Section 18.9.4 paragraphs 1 - 2 tell us that RENAME should return NFS4ERR_FILE_OPEN only when the target object is a file that is currently open. If the target is a directory, some other status must be returned. The VFS is unlikely to return -EBUSY, but NFSD has to ensure that errno does not leak to clients as a status code that is not permitted by spec. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/vfs.c | 44 +++++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index adf092406d79..4021b047eb18 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1698,9 +1698,17 @@ out: return err; } -/* - * Create a hardlink - * N.B. After this call _both_ ffhp and tfhp need an fh_put +/** + * nfsd_link - create a link + * @rqstp: RPC transaction context + * @ffhp: the file handle of the directory where the new link is to be created + * @name: the filename of the new link + * @len: the length of @name in octets + * @tfhp: the file handle of an existing file object + * + * After this call _both_ ffhp and tfhp need an fh_put. + * + * Returns a generic NFS status code in network byte-order. */ __be32 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, @@ -1708,6 +1716,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, { struct dentry *ddir, *dnew, *dold; struct inode *dirp; + int type; __be32 err; int host_err; @@ -1727,11 +1736,11 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, if (isdotent(name, len)) goto out; + err = nfs_ok; + type = d_inode(tfhp->fh_dentry)->i_mode & S_IFMT; host_err = fh_want_write(tfhp); - if (host_err) { - err = nfserrno(host_err); + if (host_err) goto out; - } ddir = ffhp->fh_dentry; dirp = d_inode(ddir); @@ -1739,7 +1748,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, dnew = lookup_one_len(name, ddir, len); if (IS_ERR(dnew)) { - err = nfserrno(PTR_ERR(dnew)); + host_err = PTR_ERR(dnew); goto out_unlock; } @@ -1755,17 +1764,26 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, fh_fill_post_attrs(ffhp); inode_unlock(dirp); if (!host_err) { - err = nfserrno(commit_metadata(ffhp)); - if (!err) - err = nfserrno(commit_metadata(tfhp)); - } else { - err = nfserrno(host_err); + host_err = commit_metadata(ffhp); + if (!host_err) + host_err = commit_metadata(tfhp); } + dput(dnew); out_drop_write: fh_drop_write(tfhp); + if (host_err == -EBUSY) { + /* + * See RFC 8881 Section 18.9.4 para 1-2: NFSv4 LINK + * wants a status unique to the object type. + */ + if (type != S_IFDIR) + err = nfserr_file_open; + else + err = nfserr_acces; + } out: - return err; + return err != nfs_ok ? err : nfserrno(host_err); out_dput: dput(dnew); -- 2.25.1