From: Andreas Gruenbacher Subject: [PATCH v11 46/48] nfs: Distinguish missing users and groups from nobody Date: Fri, 16 Oct 2015 17:18:24 +0200 Message-ID: <1445008706-15115-47-git-send-email-agruenba@redhat.com> References: <1445008706-15115-1-git-send-email-agruenba@redhat.com> To: Alexander Viro , "Theodore Ts'o" , Andreas Dilger , "J. Bruce Fields" , Jeff Layton , Trond Myklebust , Anna Schumaker , Dave Chinner , linux-ext4@vger.kernel.org, xfs@oss.sgi.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-api@vger.kernel.org Return-path: In-Reply-To: <1445008706-15115-1-git-send-email-agruenba@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org User and group names are mapped to IDs using the kernel keyring infrastructure. When a name does not exist, it is mapped to the nobody user or group; there is no way to tell the difference from the mapping result. In ACLs, we need to make that distinction. For that, use the new "xuid" and "xgid" maps: they behave like the old "uid" and "gid" maps except that the IDs of existing users and groups are prefixed by a "+" sign. When the "xuid" or "xgid" maps are not supported, nfs falls back to the "uid" and "gid" maps. Signed-off-by: Andreas Gruenbacher --- fs/nfs/nfs4idmap.c | 57 ++++++++++++++++++++++++++++++++++++++--------- fs/nfs/nfs4xdr.c | 6 +++-- include/linux/nfs_fs_sb.h | 1 + 3 files changed, 52 insertions(+), 12 deletions(-) diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c index 2e49022..34dd404 100644 --- a/fs/nfs/nfs4idmap.c +++ b/fs/nfs/nfs4idmap.c @@ -100,10 +100,12 @@ static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr { struct nfs4_string *owner = fattr->owner_name; kuid_t uid; + int ret; if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)) return false; - if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) { + ret = nfs_map_name_to_uid(server, owner->data, owner->len, &uid); + if (ret == 0 || ret == -ENOENT) { fattr->uid = uid; fattr->valid |= NFS_ATTR_FATTR_OWNER; } @@ -114,10 +116,12 @@ static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr { struct nfs4_string *group = fattr->group_name; kgid_t gid; + int ret; if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)) return false; - if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) { + ret = nfs_map_group_to_gid(server, group->data, group->len, &gid); + if (ret == 0 || ret == -ENOENT) { fattr->gid = gid; fattr->valid |= NFS_ATTR_FATTR_GROUP; } @@ -351,20 +355,23 @@ static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf, } /* Name -> ID */ +/* Returns -ENOENT for unknown names (with @id set to the nobody id). */ static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type, __u32 *id, struct idmap *idmap) { - char id_str[NFS_UINT_MAXLEN]; + char id_str[NFS_UINT_MAXLEN + 1]; long id_long; ssize_t data_size; int ret = 0; - data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap); + data_size = nfs_idmap_get_key(name, namelen, type, id_str, sizeof(id_str), idmap); if (data_size <= 0) { ret = -EINVAL; } else { ret = kstrtol(id_str, 10, &id_long); *id = (__u32)id_long; + if (!ret && *id_str != '+') + ret = -ENOENT; } return ret; } @@ -719,9 +726,24 @@ int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_ __u32 id = -1; int ret = 0; - if (!nfs_map_string_to_numeric(name, namelen, &id)) - ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap); - if (ret == 0) { + if (!nfs_map_string_to_numeric(name, namelen, &id)) { + struct nfs_client *client = server->nfs_client; + const char *type; + + for(;;) { + type = "xuid"; + if (test_bit(NFS_CS_NOXUID, &client->cl_flags)) + type = "uid"; + + ret = nfs_idmap_lookup_id(name, namelen, type, &id, idmap); + if (ret != -EINVAL || test_bit(NFS_CS_NOXUID, &client->cl_flags)) + break; + printk(KERN_NOTICE "NFS: Falling back from nfsidmap " + "xuid/xgid to uid/gid\n"); + set_bit(NFS_CS_NOXUID, &client->cl_flags); + } + } + if (ret == 0 || ret == -ENOENT) { *uid = make_kuid(&init_user_ns, id); if (!uid_valid(*uid)) ret = -ERANGE; @@ -736,9 +758,24 @@ int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size __u32 id = -1; int ret = 0; - if (!nfs_map_string_to_numeric(name, namelen, &id)) - ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap); - if (ret == 0) { + if (!nfs_map_string_to_numeric(name, namelen, &id)) { + struct nfs_client *client = server->nfs_client; + const char *type; + + for(;;) { + type = "xgid"; + if (test_bit(NFS_CS_NOXUID, &client->cl_flags)) + type = "gid"; + + ret = nfs_idmap_lookup_id(name, namelen, type, &id, idmap); + if (ret != -EINVAL || test_bit(NFS_CS_NOXUID, &client->cl_flags)) + break; + printk(KERN_NOTICE "NFS: Falling back from nfsidmap " + "xuid/xgid to uid/gid\n"); + set_bit(NFS_CS_NOXUID, &client->cl_flags); + } + } + if (ret == 0 || ret == -ENOENT) { *gid = make_kgid(&init_user_ns, id); if (!gid_valid(*gid)) ret = -ERANGE; diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index eefed15..adeb894 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -3875,7 +3875,8 @@ static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap, ret = NFS_ATTR_FATTR_OWNER_NAME; } } else if (len < XDR_MAX_NETOBJ) { - if (nfs_map_name_to_uid(server, (char *)p, len, uid) == 0) + ret = nfs_map_name_to_uid(server, (char *)p, len, uid); + if (ret == 0 || ret == -ENOENT) ret = NFS_ATTR_FATTR_OWNER; else dprintk("%s: nfs_map_name_to_uid failed!\n", @@ -3918,7 +3919,8 @@ static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap, ret = NFS_ATTR_FATTR_GROUP_NAME; } } else if (len < XDR_MAX_NETOBJ) { - if (nfs_map_group_to_gid(server, (char *)p, len, gid) == 0) + ret = nfs_map_group_to_gid(server, (char *)p, len, gid); + if (ret == 0 || ret == -ENOENT) ret = NFS_ATTR_FATTR_GROUP; else dprintk("%s: nfs_map_group_to_gid failed!\n", diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index 570a7df..c7d42b7 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -36,6 +36,7 @@ struct nfs_client { #define NFS_CS_RENEWD 3 /* - renewd started */ #define NFS_CS_STOP_RENEW 4 /* no more state to renew */ #define NFS_CS_CHECK_LEASE_TIME 5 /* need to check lease time */ +#define NFS_CS_NOXUID 6 /* don't use idmap xuid / xgid */ unsigned long cl_flags; /* behavior switches */ #define NFS_CS_NORESVPORT 0 /* - use ephemeral src port */ #define NFS_CS_DISCRTRY 1 /* - disconnect on RPC retry */ -- 2.5.0