| Message ID | 20221207084309.8499-3-richard@nod.at (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | NFS: NFSD: Allow crossing mounts when re-exporting | expand |
> On Dec 7, 2022, at 3:43 AM, Richard Weinberger <richard@nod.at> wrote: > > This function is only used by NFSD to cross mount points. > If a mount point is of type auto mount, follow_down() will > not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags > to have ->d_automount() called when NFSD walks down the > mount tree. > > Signed-off-by: Richard Weinberger <richard@nod.at> > --- > fs/namei.c | 6 +++--- > fs/nfsd/vfs.c | 6 +++++- > include/linux/namei.h | 2 +- > 3 files changed, 9 insertions(+), 5 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 578c2110df02..a6bb6863bf0c 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -1458,11 +1458,11 @@ EXPORT_SYMBOL(follow_down_one); > * point, the filesystem owning that dentry may be queried as to whether the > * caller is permitted to proceed or not. > */ > -int follow_down(struct path *path) > +int follow_down(struct path *path, unsigned int flags) > { > struct vfsmount *mnt = path->mnt; > bool jumped; > - int ret = traverse_mounts(path, &jumped, NULL, 0); > + int ret = traverse_mounts(path, &jumped, NULL, flags); > > if (path->mnt != mnt) > mntput(mnt); > @@ -2864,7 +2864,7 @@ int path_pts(struct path *path) > > path->dentry = child; > dput(parent); > - follow_down(path); > + follow_down(path, 0); > return 0; > } > #endif > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index 157f0df0e93a..ced04fc2b947 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -63,9 +63,13 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, > struct dentry *dentry = *dpp; > struct path path = {.mnt = mntget(exp->ex_path.mnt), > .dentry = dget(dentry)}; > + unsigned int follow_flags = 0; > int err = 0; > > - err = follow_down(&path); > + if (exp->ex_flags & NFSEXP_CROSSMOUNT) > + follow_flags = LOOKUP_AUTOMOUNT; > + > + err = follow_down(&path, follow_flags); > if (err < 0) > goto out; > if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && > diff --git a/include/linux/namei.h b/include/linux/namei.h > index 00fee52df842..6f96db73a70a 100644 > --- a/include/linux/namei.h > +++ b/include/linux/namei.h > @@ -77,7 +77,7 @@ struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns, > struct dentry *base, int len); > > extern int follow_down_one(struct path *); > -extern int follow_down(struct path *); > +extern int follow_down(struct path *, unsigned int flags); > extern int follow_up(struct path *); > > extern struct dentry *lock_rename(struct dentry *, struct dentry *); > -- > 2.26.2 > I plan to take this through the nfsd tree, thus this one needs an Ack from the VFS maintainer(s). -- Chuck Lever
> On Dec 7, 2022, at 3:43 AM, Richard Weinberger <richard@nod.at> wrote: > > This function is only used by NFSD to cross mount points. > If a mount point is of type auto mount, follow_down() will > not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags > to have ->d_automount() called when NFSD walks down the > mount tree. > > Signed-off-by: Richard Weinberger <richard@nod.at> Hello Al, you are top of the maintainers listed for fs/namei.c. I'd like to take this series for v6.3 via the nfsd tree. Can I get your Acked-by: for this one? > --- > fs/namei.c | 6 +++--- > fs/nfsd/vfs.c | 6 +++++- > include/linux/namei.h | 2 +- > 3 files changed, 9 insertions(+), 5 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 578c2110df02..a6bb6863bf0c 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -1458,11 +1458,11 @@ EXPORT_SYMBOL(follow_down_one); > * point, the filesystem owning that dentry may be queried as to whether the > * caller is permitted to proceed or not. > */ > -int follow_down(struct path *path) > +int follow_down(struct path *path, unsigned int flags) > { > struct vfsmount *mnt = path->mnt; > bool jumped; > - int ret = traverse_mounts(path, &jumped, NULL, 0); > + int ret = traverse_mounts(path, &jumped, NULL, flags); > > if (path->mnt != mnt) > mntput(mnt); > @@ -2864,7 +2864,7 @@ int path_pts(struct path *path) > > path->dentry = child; > dput(parent); > - follow_down(path); > + follow_down(path, 0); > return 0; > } > #endif > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index 157f0df0e93a..ced04fc2b947 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -63,9 +63,13 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, > struct dentry *dentry = *dpp; > struct path path = {.mnt = mntget(exp->ex_path.mnt), > .dentry = dget(dentry)}; > + unsigned int follow_flags = 0; > int err = 0; > > - err = follow_down(&path); > + if (exp->ex_flags & NFSEXP_CROSSMOUNT) > + follow_flags = LOOKUP_AUTOMOUNT; > + > + err = follow_down(&path, follow_flags); > if (err < 0) > goto out; > if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && > diff --git a/include/linux/namei.h b/include/linux/namei.h > index 00fee52df842..6f96db73a70a 100644 > --- a/include/linux/namei.h > +++ b/include/linux/namei.h > @@ -77,7 +77,7 @@ struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns, > struct dentry *base, int len); > > extern int follow_down_one(struct path *); > -extern int follow_down(struct path *); > +extern int follow_down(struct path *, unsigned int flags); > extern int follow_up(struct path *); > > extern struct dentry *lock_rename(struct dentry *, struct dentry *); > -- > 2.26.2 > -- Chuck Lever
----- Ursprüngliche Mail ----- > Von: "chuck lever" <chuck.lever@oracle.com> >> On Dec 7, 2022, at 3:43 AM, Richard Weinberger <richard@nod.at> wrote: >> >> This function is only used by NFSD to cross mount points. >> If a mount point is of type auto mount, follow_down() will >> not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags >> to have ->d_automount() called when NFSD walks down the >> mount tree. >> >> Signed-off-by: Richard Weinberger <richard@nod.at> > > Hello Al, you are top of the maintainers listed for fs/namei.c. > I'd like to take this series for v6.3 via the nfsd tree. Can > I get your Acked-by: for this one? ping? Thanks, //richard
On Sun, Jan 29, 2023 at 04:42:39PM +0100, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- > > Von: "chuck lever" <chuck.lever@oracle.com> > >> On Dec 7, 2022, at 3:43 AM, Richard Weinberger <richard@nod.at> wrote: > >> > >> This function is only used by NFSD to cross mount points. > >> If a mount point is of type auto mount, follow_down() will > >> not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags > >> to have ->d_automount() called when NFSD walks down the > >> mount tree. > >> > >> Signed-off-by: Richard Weinberger <richard@nod.at> > > > > Hello Al, you are top of the maintainers listed for fs/namei.c. > > I'd like to take this series for v6.3 via the nfsd tree. Can > > I get your Acked-by: for this one? > > ping? modulo clumsy wording ("mount point is of type auto mount") Acked-by: Al Viro <viro@zeniv.linux.org.uk> Commit message sounds as if it refered to autofs, rather than NFS referrals et.al. and AFAICS those are the cases it's really about...
diff --git a/fs/namei.c b/fs/namei.c index 578c2110df02..a6bb6863bf0c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1458,11 +1458,11 @@ EXPORT_SYMBOL(follow_down_one); * point, the filesystem owning that dentry may be queried as to whether the * caller is permitted to proceed or not. */ -int follow_down(struct path *path) +int follow_down(struct path *path, unsigned int flags) { struct vfsmount *mnt = path->mnt; bool jumped; - int ret = traverse_mounts(path, &jumped, NULL, 0); + int ret = traverse_mounts(path, &jumped, NULL, flags); if (path->mnt != mnt) mntput(mnt); @@ -2864,7 +2864,7 @@ int path_pts(struct path *path) path->dentry = child; dput(parent); - follow_down(path); + follow_down(path, 0); return 0; } #endif diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 157f0df0e93a..ced04fc2b947 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -63,9 +63,13 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, struct dentry *dentry = *dpp; struct path path = {.mnt = mntget(exp->ex_path.mnt), .dentry = dget(dentry)}; + unsigned int follow_flags = 0; int err = 0; - err = follow_down(&path); + if (exp->ex_flags & NFSEXP_CROSSMOUNT) + follow_flags = LOOKUP_AUTOMOUNT; + + err = follow_down(&path, follow_flags); if (err < 0) goto out; if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && diff --git a/include/linux/namei.h b/include/linux/namei.h index 00fee52df842..6f96db73a70a 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -77,7 +77,7 @@ struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns, struct dentry *base, int len); extern int follow_down_one(struct path *); -extern int follow_down(struct path *); +extern int follow_down(struct path *, unsigned int flags); extern int follow_up(struct path *); extern struct dentry *lock_rename(struct dentry *, struct dentry *);
This function is only used by NFSD to cross mount points. If a mount point is of type auto mount, follow_down() will not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags to have ->d_automount() called when NFSD walks down the mount tree. Signed-off-by: Richard Weinberger <richard@nod.at> --- fs/namei.c | 6 +++--- fs/nfsd/vfs.c | 6 +++++- include/linux/namei.h | 2 +- 3 files changed, 9 insertions(+), 5 deletions(-)