From: NeilBrown <neil@brown.name>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
David Howells <dhowells@redhat.com>,
Chuck Lever <chuck.lever@oracle.com>,
Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org, netfs@lists.linux.dev,
linux-fsdevel@vger.kernel.org
Subject: [PATCH 2/8] nfsd: Use lookup_one() rather than lookup_one_len()
Date: Fri, 14 Mar 2025 11:34:08 +1100 [thread overview]
Message-ID: <20250314045655.603377-3-neil@brown.name> (raw)
In-Reply-To: <20250314045655.603377-1-neil@brown.name>
lookup_one_len() does not support idmapped mounts and does permission
checking on the non-mapped uids. This means that nfsd cannot correctly
export idmapped mounts.
This patch changes to use lookup_one(), lookup_one_unlocked(), and
lookup_one_positive_unlocked() passing the relevant vfsmount so
idmapping can be honoured.
This requires passing the name in a qstr. Currently this is a little
clumsy, but if nfsd is changed to use qstr more broadly it will result
in a net improvement.
Note that there are still many places where nfsd uses nop_mnt_idmap so
more work is needed to properly support idmapped mounts.
Signed-off-by: NeilBrown <neil@brown.name>
---
fs/nfsd/nfs3proc.c | 3 ++-
fs/nfsd/nfs3xdr.c | 4 +++-
fs/nfsd/nfs4proc.c | 4 +++-
fs/nfsd/nfs4recover.c | 13 +++++++------
fs/nfsd/nfs4xdr.c | 4 +++-
fs/nfsd/nfsproc.c | 5 +++--
fs/nfsd/vfs.c | 17 +++++++++--------
fs/nfsd/vfs.h | 12 ++++++++++++
8 files changed, 42 insertions(+), 20 deletions(-)
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 372bdcf5e07a..457638bf0f32 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -284,7 +284,8 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
inode_lock_nested(inode, I_MUTEX_PARENT);
- child = lookup_one_len(argp->name, parent, argp->len);
+ child = lookup_one(fh_mnt(fhp), QSTR_LEN(argp->name, argp->len),
+ parent);
if (IS_ERR(child)) {
status = nfserrno(PTR_ERR(child));
goto out;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index a7a07470c1f8..54fcc814e398 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -1001,7 +1001,9 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
} else
dchild = dget(dparent);
} else
- dchild = lookup_positive_unlocked(name, dparent, namlen);
+ dchild = lookup_one_positive_unlocked(fh_mnt(fhp),
+ QSTR_LEN(name, namlen),
+ dparent);
if (IS_ERR(dchild))
return rv;
if (d_mountpoint(dchild))
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index f6e06c779d09..9e29663aaeb1 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -266,7 +266,9 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
inode_lock_nested(inode, I_MUTEX_PARENT);
- child = lookup_one_len(open->op_fname, parent, open->op_fnamelen);
+ child = lookup_one(fh_mnt(fhp),
+ QSTR_LEN(open->op_fname, open->op_fnamelen),
+ parent);
if (IS_ERR(child)) {
status = nfserrno(PTR_ERR(child));
goto out;
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index c1d9bd07285f..10d24bec532f 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -218,7 +218,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
/* lock the parent */
inode_lock(d_inode(dir));
- dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
+ dentry = lookup_one(nn->rec_file->f_path.mnt, QSTR(dname), dir);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
@@ -316,7 +316,8 @@ nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
if (!status) {
struct dentry *dentry;
- dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
+ dentry = lookup_one(nn->rec_file->f_path.mnt,
+ QSTR(entry->name), dir);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
break;
@@ -339,16 +340,16 @@ nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
}
static int
-nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
+nfsd4_unlink_clid_dir(char *name, struct nfsd_net *nn)
{
struct dentry *dir, *dentry;
int status;
- dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
+ dprintk("NFSD: nfsd4_unlink_clid_dir. name %s\n", name);
dir = nn->rec_file->f_path.dentry;
inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
- dentry = lookup_one_len(name, dir, namlen);
+ dentry = lookup_one(nn->rec_file->f_path.mnt, QSTR(name), dir);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
@@ -408,7 +409,7 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
if (status < 0)
goto out_drop_write;
- status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
+ status = nfsd4_unlink_clid_dir(dname, nn);
nfs4_reset_creds(original_cred);
if (status == 0) {
vfs_fsync(nn->rec_file, 0);
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index e67420729ecd..64ab2c605e93 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3812,7 +3812,9 @@ nfsd4_encode_entry4_fattr(struct nfsd4_readdir *cd, const char *name,
__be32 nfserr;
int ignore_crossmnt = 0;
- dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
+ dentry = lookup_one_positive_unlocked(fh_mnt(cd->rd_fhp),
+ QSTR_LEN(name, namlen),
+ cd->rd_fhp->fh_dentry);
if (IS_ERR(dentry))
return nfserrno(PTR_ERR(dentry));
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6dda081eb24c..a84719935690 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -312,7 +312,8 @@ nfsd_proc_create(struct svc_rqst *rqstp)
}
inode_lock_nested(dirfhp->fh_dentry->d_inode, I_MUTEX_PARENT);
- dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
+ dchild = lookup_one(fh_mnt(dirfhp), QSTR_LEN(argp->name, argp->len),
+ dirfhp->fh_dentry);
if (IS_ERR(dchild)) {
resp->status = nfserrno(PTR_ERR(dchild));
goto out_unlock;
@@ -331,7 +332,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
*/
resp->status = nfserr_acces;
if (!newfhp->fh_dentry) {
- printk(KERN_WARNING
+ printk(KERN_WARNING
"nfsd_proc_create: file handle not verified\n");
goto out_unlock;
}
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 34d7aa531662..2829799bcd08 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -265,7 +265,8 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
goto out_nfserr;
}
} else {
- dentry = lookup_one_len_unlocked(name, dparent, len);
+ dentry = lookup_one_unlocked(fh_mnt(fhp), QSTR_LEN(name, len),
+ dparent);
host_err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_nfserr;
@@ -923,7 +924,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
* directories, but we never have and it doesn't seem to have
* caused anyone a problem. If we were to change this, note
* also that our filldir callbacks would need a variant of
- * lookup_one_len that doesn't check permissions.
+ * lookup_one_positive_unlocked() that doesn't check permissions.
*/
if (type == S_IFREG)
may_flags |= NFSD_MAY_OWNER_OVERRIDE;
@@ -1555,7 +1556,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
return nfserrno(host_err);
inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
- dchild = lookup_one_len(fname, dentry, flen);
+ dchild = lookup_one(fh_mnt(fhp), QSTR_LEN(fname, flen), dentry);
host_err = PTR_ERR(dchild);
if (IS_ERR(dchild)) {
err = nfserrno(host_err);
@@ -1660,7 +1661,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
dentry = fhp->fh_dentry;
inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
- dnew = lookup_one_len(fname, dentry, flen);
+ dnew = lookup_one(fh_mnt(fhp), QSTR_LEN(fname, flen), dentry);
if (IS_ERR(dnew)) {
err = nfserrno(PTR_ERR(dnew));
inode_unlock(dentry->d_inode);
@@ -1726,7 +1727,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
dirp = d_inode(ddir);
inode_lock_nested(dirp, I_MUTEX_PARENT);
- dnew = lookup_one_len(name, ddir, len);
+ dnew = lookup_one(fh_mnt(ffhp), QSTR_LEN(name, len), ddir);
if (IS_ERR(dnew)) {
err = nfserrno(PTR_ERR(dnew));
goto out_unlock;
@@ -1839,7 +1840,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
if (err != nfs_ok)
goto out_unlock;
- odentry = lookup_one_len(fname, fdentry, flen);
+ odentry = lookup_one(fh_mnt(ffhp), QSTR_LEN(fname, flen), fdentry);
host_err = PTR_ERR(odentry);
if (IS_ERR(odentry))
goto out_nfserr;
@@ -1851,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
if (odentry == trap)
goto out_dput_old;
- ndentry = lookup_one_len(tname, tdentry, tlen);
+ ndentry = lookup_one(fh_mnt(tfhp), QSTR_LEN(tname, tlen), tdentry);
host_err = PTR_ERR(ndentry);
if (IS_ERR(ndentry))
goto out_dput_old;
@@ -1948,7 +1949,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
dirp = d_inode(dentry);
inode_lock_nested(dirp, I_MUTEX_PARENT);
- rdentry = lookup_one_len(fname, dentry, flen);
+ rdentry = lookup_one(fh_mnt(fhp), QSTR_LEN(fname, flen), dentry);
host_err = PTR_ERR(rdentry);
if (IS_ERR(rdentry))
goto out_unlock;
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index f9b09b842856..5a60004468b8 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -193,4 +193,16 @@ static inline __be32 fh_getattr(const struct svc_fh *fh, struct kstat *stat)
AT_STATX_SYNC_AS_STAT));
}
+/**
+ * fh_mnt - access vfsmount of a given file handle
+ * @fhp: the filehandle
+ *
+ * Returns the struct vfsmount from the export referenced in the
+ * filehandle.
+ */
+static inline struct vfsmount *fh_mnt(struct svc_fh *fhp)
+{
+ return fhp->fh_export->ex_path.mnt;
+}
+
#endif /* LINUX_NFSD_VFS_H */
--
2.48.1
next prev parent reply other threads:[~2025-03-14 4:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-14 0:34 [PATCH 0/8 RFC] tidy up various VFS lookup functions NeilBrown
2025-03-14 0:34 ` [PATCH 1/8] VFS: improve interface for lookup_one functions NeilBrown
2025-03-14 0:34 ` NeilBrown [this message]
2025-03-14 0:34 ` [PATCH 3/8] nfsd: use correct idmap for all accesses NeilBrown
2025-03-14 0:34 ` [PATCH 4/8] cachefiles: Use lookup_one() rather than lookup_one_len() NeilBrown
2025-03-14 0:34 ` [PATCH 5/8] cachefiles: use correct mnt_idmap NeilBrown
2025-03-14 0:34 ` [PATCH 6/8] VFS: rename lookup_one_len() family to lookup_noperm() and remove permission check NeilBrown
2025-03-14 0:34 ` [PATCH 7/8] Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS NeilBrown
2025-03-14 0:34 ` [PATCH 8/8] VFS: change lookup_one_common and lookup_noperm_common to take a qstr NeilBrown
2025-03-14 10:38 ` [PATCH 0/8 RFC] tidy up various VFS lookup functions Christian Brauner
2025-03-17 2:06 ` NeilBrown
2025-03-18 13:57 ` Christian Brauner
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