From de9cf600400b8243bf017141f91465e905687db0 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sun, 21 Jun 2026 17:35:35 -0400 Subject: [PATCH] NFSD: Replace isdotent() macro The VFS provides name_is_dot_dotdot() as the canonical helper for recognizing the "." and ".." directory entries, and fs/ already uses it widely. nfsd has instead carried its own open-coded isdotent() macro that computes the same predicate for non-empty names, a needless duplicate of shared functionality. The macro reads the first name byte without first confirming the name is non-empty; name_is_dot_dotdot() tests the length first, so it never touches a zero-length buffer. Convert every isdotent() call site to the generic helper and remove the macro. Reviewed-by: Jeff Layton Link: https://patch.msgid.link/20260621213535.539450-1-cel@kernel.org Signed-off-by: Chuck Lever --- fs/nfsd/nfs3proc.c | 2 +- fs/nfsd/nfs3xdr.c | 2 +- fs/nfsd/nfs4proc.c | 2 +- fs/nfsd/nfs4xdr.c | 4 ++-- fs/nfsd/nfsd.h | 3 --- fs/nfsd/nfsproc.c | 2 +- fs/nfsd/vfs.c | 13 +++++++------ 7 files changed, 13 insertions(+), 15 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 617a70d13292..bbaef884f893 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -291,7 +291,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, if (!nfsd3_time_in_range(iap)) return nfserr_inval; - if (isdotent(argp->name, argp->len)) + if (name_is_dot_dotdot(argp->name, argp->len)) return nfserr_exist; if (!(iap->ia_valid & ATTR_MODE)) iap->ia_mode = 0; diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 2ff9a991a8fb..e481804bb120 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -987,7 +987,7 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp, dparent = cd->fh.fh_dentry; exp = cd->fh.fh_export; - if (isdotent(name, namlen)) { + if (name_is_dot_dotdot(name, namlen)) { if (namlen == 2) { dchild = dget_parent(dparent); /* diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 8351ccaae59c..669896be08b6 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -259,7 +259,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, __be32 status; int host_err; - if (isdotent(open->op_fname, open->op_fnamelen)) + if (name_is_dot_dotdot(open->op_fname, open->op_fnamelen)) return nfserr_exist; if (!(iap->ia_valid & ATTR_MODE)) iap->ia_mode = 0; diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 3affb144c66a..aef48fb0fac2 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -98,7 +98,7 @@ check_filename(char *str, int len) return nfserr_inval; if (len > NFS4_MAXNAMLEN) return nfserr_nametoolong; - if (isdotent(str, len)) + if (name_is_dot_dotdot(str, len)) return nfserr_badname; for (i = 0; i < len; i++) if (str[i] == '/') @@ -4629,7 +4629,7 @@ nfsd4_encode_entry4(void *ccdv, const char *name, int namlen, __be32 nfserr = nfserr_toosmall; /* In nfsv4, "." and ".." never make it onto the wire.. */ - if (name && isdotent(name, namlen)) { + if (name && name_is_dot_dotdot(name, namlen)) { cd->common.err = nfs_ok; return 0; } diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index d33d49b61e6a..4c5d915225df 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -357,9 +357,6 @@ enum { #define nfserr_symlink_not_dir cpu_to_be32(NFSERR_SYMLINK_NOT_DIR) }; -/* Check for dir entries '.' and '..' */ -#define isdotent(n, l) (l < 3 && n[0] == '.' && (l == 1 || n[1] == '.')) - #ifdef CONFIG_NFSD_V4 /* before processing a COMPOUND operation, we have to check that there diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index a73d5c259cd9..f60043632575 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -305,7 +305,7 @@ nfsd_proc_create(struct svc_rqst *rqstp) /* Check for NFSD_MAY_WRITE in nfsd_create if necessary */ resp->status = nfserr_exist; - if (isdotent(argp->name, argp->len)) + if (name_is_dot_dotdot(argp->name, argp->len)) goto done; hosterr = fh_want_write(dirfhp); if (hosterr) { diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index c81aea23363a..9e05c3949cc1 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -255,7 +255,7 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, exp = exp_get(fhp->fh_export); /* Lookup the name, but don't follow links */ - if (isdotent(name, len)) { + if (name_is_dot_dotdot(name, len)) { if (len==1) dentry = dget(dparent); else if (dparent != exp->ex_path.dentry) @@ -1884,7 +1884,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, trace_nfsd_vfs_create(rqstp, fhp, type, fname, flen); - if (isdotent(fname, flen)) + if (name_is_dot_dotdot(fname, flen)) return nfserr_exist; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP); @@ -1986,7 +1986,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, if (!flen || path[0] == '\0') goto out; err = nfserr_exist; - if (isdotent(fname, flen)) + if (name_is_dot_dotdot(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); @@ -2063,7 +2063,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, if (!len) goto out; err = nfserr_exist; - if (isdotent(name, len)) + if (name_is_dot_dotdot(name, len)) goto out; err = nfs_ok; @@ -2174,7 +2174,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, tdentry = tfhp->fh_dentry; err = nfserr_perm; - if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) + if (!flen || name_is_dot_dotdot(fname, flen) || + !tlen || name_is_dot_dotdot(tname, tlen)) goto out; err = nfserr_xdev; @@ -2296,7 +2297,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, trace_nfsd_vfs_unlink(rqstp, fhp, fname, flen); err = nfserr_acces; - if (!flen || isdotent(fname, flen)) + if (!flen || name_is_dot_dotdot(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); if (err)