On Mon, Aug 7, 2023 at 12:28 PM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > > > On 8/7/23 14:51, Aleksandr Mikhalitsyn wrote: > > On Mon, Aug 7, 2023 at 3:25 AM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > >> > >> On 8/4/23 16:48, Alexander Mikhalitsyn wrote: > >>> From: Christian Brauner <brauner@xxxxxxxxxx> > >>> > >>> Inode operations that create a new filesystem object such as ->mknod, > >>> ->create, ->mkdir() and others don't take a {g,u}id argument explicitly. > >>> Instead the caller's fs{g,u}id is used for the {g,u}id of the new > >>> filesystem object. > >>> > >>> In order to ensure that the correct {g,u}id is used map the caller's > >>> fs{g,u}id for creation requests. This doesn't require complex changes. > >>> It suffices to pass in the relevant idmapping recorded in the request > >>> message. If this request message was triggered from an inode operation > >>> that creates filesystem objects it will have passed down the relevant > >>> idmaping. If this is a request message that was triggered from an inode > >>> operation that doens't need to take idmappings into account the initial > >>> idmapping is passed down which is an identity mapping. > >>> > >>> This change uses a new cephfs protocol extension CEPHFS_FEATURE_HAS_OWNER_UIDGID > >>> which adds two new fields (owner_{u,g}id) to the request head structure. > >>> So, we need to ensure that MDS supports it otherwise we need to fail > >>> any IO that comes through an idmapped mount because we can't process it > >>> in a proper way. MDS server without such an extension will use caller_{u,g}id > >>> fields to set a new inode owner UID/GID which is incorrect because caller_{u,g}id > >>> values are unmapped. At the same time we can't map these fields with an > >>> idmapping as it can break UID/GID-based permission checks logic on the > >>> MDS side. This problem was described with a lot of details at [1], [2]. > >>> > >>> [1] https://lore.kernel.org/lkml/CAEivzxfw1fHO2TFA4dx3u23ZKK6Q+EThfzuibrhA3RKM=ZOYLg@xxxxxxxxxxxxxx/ > >>> [2] https://lore.kernel.org/all/20220104140414.155198-3-brauner@xxxxxxxxxx/ > >>> > >>> Link: https://github.com/ceph/ceph/pull/52575 > >>> Link: https://tracker.ceph.com/issues/62217 > >>> Cc: Xiubo Li <xiubli@xxxxxxxxxx> > >>> Cc: Jeff Layton <jlayton@xxxxxxxxxx> > >>> Cc: Ilya Dryomov <idryomov@xxxxxxxxx> > >>> Cc: ceph-devel@xxxxxxxxxxxxxxx > >>> Co-Developed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> > >>> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> > >>> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> > >>> --- > >>> v7: > >>> - reworked to use two new fields for owner UID/GID (https://github.com/ceph/ceph/pull/52575) > >>> v8: > >>> - properly handled case when old MDS used with new kernel client > >>> --- > >>> fs/ceph/mds_client.c | 47 +++++++++++++++++++++++++++++++++--- > >>> fs/ceph/mds_client.h | 5 +++- > >>> include/linux/ceph/ceph_fs.h | 5 +++- > >>> 3 files changed, 52 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > >>> index 8829f55103da..41e4bf3811c4 100644 > >>> --- a/fs/ceph/mds_client.c > >>> +++ b/fs/ceph/mds_client.c > >>> @@ -2902,6 +2902,17 @@ static void encode_mclientrequest_tail(void **p, const struct ceph_mds_request * > >>> } > >>> } > >>> > >>> +static inline u16 mds_supported_head_version(struct ceph_mds_session *session) > >>> +{ > >>> + if (!test_bit(CEPHFS_FEATURE_32BITS_RETRY_FWD, &session->s_features)) > >>> + return 1; > >>> + > >>> + if (!test_bit(CEPHFS_FEATURE_HAS_OWNER_UIDGID, &session->s_features)) > >>> + return 2; > >>> + > >>> + return CEPH_MDS_REQUEST_HEAD_VERSION; > >>> +} > >>> + > >>> static struct ceph_mds_request_head_legacy * > >>> find_legacy_request_head(void *p, u64 features) > >>> { > >>> @@ -2923,6 +2934,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, > >>> { > >>> int mds = session->s_mds; > >>> struct ceph_mds_client *mdsc = session->s_mdsc; > >>> + struct ceph_client *cl = mdsc->fsc->client; > >>> struct ceph_msg *msg; > >>> struct ceph_mds_request_head_legacy *lhead; > >>> const char *path1 = NULL; > >>> @@ -2936,7 +2948,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, > >>> void *p, *end; > >>> int ret; > >>> bool legacy = !(session->s_con.peer_features & CEPH_FEATURE_FS_BTIME); > >>> - bool old_version = !test_bit(CEPHFS_FEATURE_32BITS_RETRY_FWD, &session->s_features); > >>> + u16 request_head_version = mds_supported_head_version(session); > >>> > >>> ret = set_request_path_attr(mdsc, req->r_inode, req->r_dentry, > >>> req->r_parent, req->r_path1, req->r_ino1.ino, > >>> @@ -2977,8 +2989,10 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, > >>> */ > >>> if (legacy) > >>> len = sizeof(struct ceph_mds_request_head_legacy); > >>> - else if (old_version) > >>> + else if (request_head_version == 1) > >>> len = sizeof(struct ceph_mds_request_head_old); > >>> + else if (request_head_version == 2) > >>> + len = offsetofend(struct ceph_mds_request_head, ext_num_fwd); > >>> else > >>> len = sizeof(struct ceph_mds_request_head); > >>> > >>> @@ -3028,6 +3042,16 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, > >>> lhead = find_legacy_request_head(msg->front.iov_base, > >>> session->s_con.peer_features); > >>> > >>> + if ((req->r_mnt_idmap != &nop_mnt_idmap) && > >>> + !test_bit(CEPHFS_FEATURE_HAS_OWNER_UIDGID, &session->s_features)) { > >>> + pr_err_ratelimited_client(cl, > >>> + "idmapped mount is used and CEPHFS_FEATURE_HAS_OWNER_UIDGID" > >>> + " is not supported by MDS. Fail request with -EIO.\n"); > >>> + > >>> + ret = -EIO; > >>> + goto out_err; > >>> + } > >>> + > >>> /* > >>> * The ceph_mds_request_head_legacy didn't contain a version field, and > >>> * one was added when we moved the message version from 3->4. > >>> @@ -3035,17 +3059,34 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, > >>> if (legacy) { > >>> msg->hdr.version = cpu_to_le16(3); > >>> p = msg->front.iov_base + sizeof(*lhead); > >>> - } else if (old_version) { > >>> + } else if (request_head_version == 1) { > >>> struct ceph_mds_request_head_old *ohead = msg->front.iov_base; > >>> > >>> msg->hdr.version = cpu_to_le16(4); > >>> ohead->version = cpu_to_le16(1); > >>> p = msg->front.iov_base + sizeof(*ohead); > >>> + } else if (request_head_version == 2) { > >>> + struct ceph_mds_request_head *nhead = msg->front.iov_base; > >>> + > >>> + msg->hdr.version = cpu_to_le16(6); > >>> + nhead->version = cpu_to_le16(2); > >>> + > >>> + p = msg->front.iov_base + offsetofend(struct ceph_mds_request_head, ext_num_fwd); > >>> } else { > >>> struct ceph_mds_request_head *nhead = msg->front.iov_base; > >>> + kuid_t owner_fsuid; > >>> + kgid_t owner_fsgid; > >>> > >>> msg->hdr.version = cpu_to_le16(6); > >>> nhead->version = cpu_to_le16(CEPH_MDS_REQUEST_HEAD_VERSION); > >>> + nhead->struct_len = sizeof(struct ceph_mds_request_head); > >>> + > >>> + owner_fsuid = from_vfsuid(req->r_mnt_idmap, &init_user_ns, > >>> + VFSUIDT_INIT(req->r_cred->fsuid)); > >>> + owner_fsgid = from_vfsgid(req->r_mnt_idmap, &init_user_ns, > >>> + VFSGIDT_INIT(req->r_cred->fsgid)); > >>> + nhead->owner_uid = cpu_to_le32(from_kuid(&init_user_ns, owner_fsuid)); > >>> + nhead->owner_gid = cpu_to_le32(from_kgid(&init_user_ns, owner_fsgid)); > >>> p = msg->front.iov_base + sizeof(*nhead); > >>> } > >>> > >>> diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h > >>> index e3bbf3ba8ee8..8f683e8203bd 100644 > >>> --- a/fs/ceph/mds_client.h > >>> +++ b/fs/ceph/mds_client.h > >>> @@ -33,8 +33,10 @@ enum ceph_feature_type { > >>> CEPHFS_FEATURE_NOTIFY_SESSION_STATE, > >>> CEPHFS_FEATURE_OP_GETVXATTR, > >>> CEPHFS_FEATURE_32BITS_RETRY_FWD, > >>> + CEPHFS_FEATURE_NEW_SNAPREALM_INFO, > >>> + CEPHFS_FEATURE_HAS_OWNER_UIDGID, > >>> > >>> - CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_32BITS_RETRY_FWD, > >>> + CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_HAS_OWNER_UIDGID, > >>> }; > >>> > >>> #define CEPHFS_FEATURES_CLIENT_SUPPORTED { \ > >>> @@ -49,6 +51,7 @@ enum ceph_feature_type { > >>> CEPHFS_FEATURE_NOTIFY_SESSION_STATE, \ > >>> CEPHFS_FEATURE_OP_GETVXATTR, \ > >>> CEPHFS_FEATURE_32BITS_RETRY_FWD, \ > >>> + CEPHFS_FEATURE_HAS_OWNER_UIDGID, \ > >>> } > >>> > >>> /* > >>> diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h > >>> index 5f2301ee88bc..b91699b08f26 100644 > >>> --- a/include/linux/ceph/ceph_fs.h > >>> +++ b/include/linux/ceph/ceph_fs.h > >>> @@ -499,7 +499,7 @@ struct ceph_mds_request_head_legacy { > >>> union ceph_mds_request_args args; > >>> } __attribute__ ((packed)); > >>> > >>> -#define CEPH_MDS_REQUEST_HEAD_VERSION 2 > >>> +#define CEPH_MDS_REQUEST_HEAD_VERSION 3 > >>> > >>> struct ceph_mds_request_head_old { > >>> __le16 version; /* struct version */ > >>> @@ -530,6 +530,9 @@ struct ceph_mds_request_head { > >>> > >>> __le32 ext_num_retry; /* new count retry attempts */ > >>> __le32 ext_num_fwd; /* new count fwd attempts */ > >>> + > >>> + __le32 struct_len; /* to store size of struct ceph_mds_request_head */ > >>> + __le32 owner_uid, owner_gid; /* used for OPs which create inodes */ > >> Let's also initialize them to -1 for all the other requests as we do in > >> your PR. > > They are always initialized already. As you can see from the code we > > don't have any extra conditions > > on filling these fields. We always fill them with an appropriate > > UID/GID. If mount is not idmapped then it's just == caller_uid/gid, > > if mount idmapped then it's idmapped caller_uid/gid. > > Then in kclient all the request will always initialized the > 'owner_{uid/gid}' with 'caller_{uid/gid}'. While in userspace libcephfs > it will only set them for 'create/mknod/mkdir/symlink` instead. > > I'd prefer to make them consistent, which is what I am still focusing > on, to make them easier to read and comparing when troubles hooting. Dear Xiubo, Sure, I will do it. Couldn't you please review all the rest of the patches before I fix this particular thing? It will allow me to fix and send -v10 with all required fixes incorporated in it. Kind regards, Alex > > Thanks > > - Xiubo > > > Kind regards, > > Alex > > > >> Thanks > >> > >> - Xiubo > >> > >> > >> > >>> } __attribute__ ((packed)); > >>> > >>> /* cap/lease release record */ >