vfs: add NDFREE_NOTHING and convert several NDFREE_PNBUF callers

Check the comment above the routine for reasoning.
This commit is contained in:
Mateusz Guzik 2021-01-12 12:36:30 +01:00
parent 6b3a9a0f3d
commit cdb62ab74e
4 changed files with 47 additions and 18 deletions

View File

@ -1568,7 +1568,7 @@ unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
else else
vp = nd.ni_vp; vp = nd.ni_vp;
ASSERT_VOP_LOCKED(vp, "unp_connect"); ASSERT_VOP_LOCKED(vp, "unp_connect");
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
if (error) if (error)
goto bad; goto bad;

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@ -1487,6 +1487,33 @@ NDFREE_PNBUF(struct nameidata *ndp)
} }
} }
/*
* NDFREE_PNBUF replacement for callers that know there is no buffer.
*
* This is a hack. Preferably the VFS layer would not produce anything more
* than it was asked to do. Unfortunately several non-LOOKUP cases can add the
* HASBUF flag to the result. Even then an interface could be implemented where
* the caller specifies what they expected to see in the result and what they
* are going to take care of.
*
* In the meantime provide this kludge as a trivial replacement for NDFREE_PNBUF
* calls scattered throughout the kernel where we know for a fact the flag must not
* be seen.
*/
#ifdef INVARIANTS
void
NDFREE_NOTHING(struct nameidata *ndp)
{
struct componentname *cnp;
cnp = &ndp->ni_cnd;
KASSERT(cnp->cn_nameiop == LOOKUP, ("%s: got non-LOOKUP op %d\n",
__func__, cnp->cn_nameiop));
KASSERT((cnp->cn_flags & (SAVENAME | HASBUF)) == 0,
("%s: bad flags \%" PRIx64 "\n", __func__, cnp->cn_flags));
}
#endif
void void
(NDFREE)(struct nameidata *ndp, const u_int flags) (NDFREE)(struct nameidata *ndp, const u_int flags)
{ {

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@ -340,7 +340,7 @@ kern_statfs(struct thread *td, const char *path, enum uio_seg pathseg,
return (error); return (error);
mp = nd.ni_vp->v_mount; mp = nd.ni_vp->v_mount;
vfs_ref(mp); vfs_ref(mp);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
vput(nd.ni_vp); vput(nd.ni_vp);
return (kern_do_statfs(td, mp, buf)); return (kern_do_statfs(td, mp, buf));
} }
@ -949,11 +949,11 @@ kern_chdir(struct thread *td, const char *path, enum uio_seg pathseg)
return (error); return (error);
if ((error = change_dir(nd.ni_vp, td)) != 0) { if ((error = change_dir(nd.ni_vp, td)) != 0) {
vput(nd.ni_vp); vput(nd.ni_vp);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
return (error); return (error);
} }
VOP_UNLOCK(nd.ni_vp); VOP_UNLOCK(nd.ni_vp);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
pwd_chdir(td, nd.ni_vp); pwd_chdir(td, nd.ni_vp);
return (0); return (0);
} }
@ -991,12 +991,12 @@ sys_chroot(struct thread *td, struct chroot_args *uap)
VOP_UNLOCK(nd.ni_vp); VOP_UNLOCK(nd.ni_vp);
error = pwd_chroot(td, nd.ni_vp); error = pwd_chroot(td, nd.ni_vp);
vrele(nd.ni_vp); vrele(nd.ni_vp);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
return (error); return (error);
e_vunlock: e_vunlock:
vput(nd.ni_vp); vput(nd.ni_vp);
error: error:
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
return (error); return (error);
} }
@ -2118,7 +2118,7 @@ kern_accessat(struct thread *td, int fd, const char *path,
vp = nd.ni_vp; vp = nd.ni_vp;
error = vn_access(vp, amode, usecred, td); error = vn_access(vp, amode, usecred, td);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
vput(vp); vput(vp);
out: out:
if (usecred != cred) { if (usecred != cred) {
@ -2417,7 +2417,7 @@ kern_statat(struct thread *td, int flag, int fd, const char *path,
if (__predict_false(hook != NULL)) if (__predict_false(hook != NULL))
hook(nd.ni_vp, sbp); hook(nd.ni_vp, sbp);
} }
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
vput(nd.ni_vp); vput(nd.ni_vp);
#ifdef __STAT_TIME_T_EXT #ifdef __STAT_TIME_T_EXT
sbp->st_atim_ext = 0; sbp->st_atim_ext = 0;
@ -2557,7 +2557,7 @@ kern_pathconf(struct thread *td, const char *path, enum uio_seg pathseg,
pathseg, path, td); pathseg, path, td);
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = VOP_PATHCONF(nd.ni_vp, name, valuep); error = VOP_PATHCONF(nd.ni_vp, name, valuep);
vput(nd.ni_vp); vput(nd.ni_vp);
@ -2613,7 +2613,7 @@ kern_readlinkat(struct thread *td, int fd, const char *path,
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
vp = nd.ni_vp; vp = nd.ni_vp;
error = kern_readlink_vp(vp, buf, bufseg, count, td); error = kern_readlink_vp(vp, buf, bufseg, count, td);
@ -2764,7 +2764,7 @@ kern_chflagsat(struct thread *td, int fd, const char *path,
&cap_fchflags_rights, td); &cap_fchflags_rights, td);
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = setfflags(td, nd.ni_vp, flags); error = setfflags(td, nd.ni_vp, flags);
vrele(nd.ni_vp); vrele(nd.ni_vp);
return (error); return (error);
@ -2893,7 +2893,7 @@ kern_fchmodat(struct thread *td, int fd, const char *path,
&cap_fchmod_rights, td); &cap_fchmod_rights, td);
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = setfmode(td, td->td_ucred, nd.ni_vp, mode); error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
vrele(nd.ni_vp); vrele(nd.ni_vp);
return (error); return (error);
@ -3006,7 +3006,7 @@ kern_fchownat(struct thread *td, int fd, const char *path,
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid); error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
vrele(nd.ni_vp); vrele(nd.ni_vp);
return (error); return (error);
@ -3219,7 +3219,7 @@ kern_utimesat(struct thread *td, int fd, const char *path,
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL); error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
vrele(nd.ni_vp); vrele(nd.ni_vp);
return (error); return (error);
@ -3255,7 +3255,7 @@ kern_lutimes(struct thread *td, const char *path, enum uio_seg pathseg,
NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td); NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td);
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL); error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
vrele(nd.ni_vp); vrele(nd.ni_vp);
return (error); return (error);
@ -3370,7 +3370,7 @@ kern_utimensat(struct thread *td, int fd, const char *path,
* "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected." * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
* "Search permission is denied by a component of the path prefix." * "Search permission is denied by a component of the path prefix."
*/ */
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
if ((flags & UTIMENS_EXIT) == 0) if ((flags & UTIMENS_EXIT) == 0)
error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL); error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
vrele(nd.ni_vp); vrele(nd.ni_vp);
@ -4226,7 +4226,7 @@ sys_revoke(struct thread *td, struct revoke_args *uap)
if ((error = namei(&nd)) != 0) if ((error = namei(&nd)) != 0)
return (error); return (error);
vp = nd.ni_vp; vp = nd.ni_vp;
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
if (vp->v_type != VCHR || vp->v_rdev == NULL) { if (vp->v_type != VCHR || vp->v_rdev == NULL) {
error = EINVAL; error = EINVAL;
goto out; goto out;
@ -4361,7 +4361,7 @@ kern_getfhat(struct thread *td, int flags, int fd, const char *path,
error = namei(&nd); error = namei(&nd);
if (error != 0) if (error != 0)
return (error); return (error);
NDFREE(&nd, NDF_ONLY_PNBUF); NDFREE_NOTHING(&nd);
vp = nd.ni_vp; vp = nd.ni_vp;
bzero(&fh, sizeof(fh)); bzero(&fh, sizeof(fh));
fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid; fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;

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@ -288,8 +288,10 @@ void NDFREE(struct nameidata *, const u_int);
} while (0) } while (0)
#ifdef INVARIANTS #ifdef INVARIANTS
void NDFREE_NOTHING(struct nameidata *);
void NDVALIDATE(struct nameidata *); void NDVALIDATE(struct nameidata *);
#else #else
#define NDFREE_NOTHING(ndp) do { } while (0)
#define NDVALIDATE(ndp) do { } while (0) #define NDVALIDATE(ndp) do { } while (0)
#endif #endif