vfs_ceph_new: use low-level APIs for stat

Start migrating to libcephfs' low-level APIs, using explicit Inode*
reference. Implement the VFS 'stat' hook using a ceph_ll_getattr
function, encapsulated with a pair of iget/iput to hold a
pinned-to-cache Inode* instance.

Upon calling to libcephfs this new code crates and destroys on-the-fly
a Ceph UserPerm instance based on the uig, gid and groups from
'handle->conn->session_info->unix_token'. This logic ensures that the
correct caller-credentials are passed-on to cephfs (instead of those
set upon connection-creation in legacy 'vfs_ceph.c').

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15686

Signed-off-by: Shachar Sharon <ssharon@redhat.com>
Reviewed-by: Guenther Deschner <gd@samba.org>
Reviewed-by: Anoop C S <anoopcs@samba.org>

diff --git a/source3/modules/vfs_ceph_new.c b/source3/modules/vfs_ceph_new.c
index 722a2aed4f492ab664642de84df2fd64dd82b6d0..1b22a0026c33939041773a98d5021c9f3f0f6fb0 100644 (file)
--- a/source3/modules/vfs_ceph_new.c
+++ b/source3/modules/vfs_ceph_new.c
@@ -335,6 +335,175 @@ static void vfs_ceph_disconnect(struct vfs_handle_struct *handle)
        handle->data = NULL;
 }
 
+/* Ceph user-credentials */
+static struct UserPerm *vfs_ceph_userperm_new(
+       const struct vfs_handle_struct *handle)
+{
+       const struct security_unix_token *unix_token = NULL;
+
+       unix_token = get_current_utok(handle->conn);
+       return ceph_userperm_new(unix_token->uid,
+                                unix_token->gid,
+                                unix_token->ngroups,
+                                unix_token->groups);
+}
+
+static void vfs_ceph_userperm_del(struct UserPerm *uperm)
+{
+       if (uperm != NULL) {
+               ceph_userperm_destroy(uperm);
+       }
+}
+
+/* Ceph's statx to Samba's stat_ex */
+#define SAMBA_STATX_ATTR_MASK (CEPH_STATX_BASIC_STATS | CEPH_STATX_BTIME)
+
+static void smb_stat_from_ceph_statx(SMB_STRUCT_STAT *st,
+                                    const struct ceph_statx *stx)
+{
+       ZERO_STRUCTP(st);
+
+       st->st_ex_dev = stx->stx_dev;
+       st->st_ex_rdev = stx->stx_rdev;
+       st->st_ex_ino = stx->stx_ino;
+       st->st_ex_mode = stx->stx_mode;
+       st->st_ex_uid = stx->stx_uid;
+       st->st_ex_gid = stx->stx_gid;
+       st->st_ex_size = stx->stx_size;
+       st->st_ex_nlink = stx->stx_nlink;
+       st->st_ex_atime = stx->stx_atime;
+       st->st_ex_btime = stx->stx_btime;
+       st->st_ex_ctime = stx->stx_ctime;
+       st->st_ex_mtime = stx->stx_mtime;
+       st->st_ex_blksize = stx->stx_blksize;
+       st->st_ex_blocks = stx->stx_blocks;
+}
+
+/* Ceph's inode + ino-number */
+struct vfs_ceph_iref {
+       struct Inode *inode;
+       uint64_t ino; /* for debug printing */
+};
+
+/* Ceph low-level wrappers */
+
+static int vfs_ceph_ll_lookup_inode(const struct vfs_handle_struct *handle,
+                                   uint64_t inoval,
+                                   Inode **pout)
+{
+       struct inodeno_t ino = {.val = inoval};
+
+       return ceph_ll_lookup_inode(handle->data, ino, pout);
+}
+
+static int vfs_ceph_ll_walk(const struct vfs_handle_struct *handle,
+                           const char *name,
+                           struct Inode **pin,
+                           struct ceph_statx *stx,
+                           unsigned int want,
+                           unsigned int flags)
+{
+       struct UserPerm *uperm = NULL;
+       int ret = -1;
+
+       uperm = vfs_ceph_userperm_new(handle);
+       if (uperm == NULL) {
+               return -ENOMEM;
+       }
+       ret = ceph_ll_walk(handle->data, name, pin, stx, want, flags, uperm);
+       vfs_ceph_userperm_del(uperm);
+       return ret;
+}
+
+static int vfs_ceph_ll_getattr(const struct vfs_handle_struct *handle,
+                              const struct vfs_ceph_iref *iref,
+                              SMB_STRUCT_STAT *st)
+{
+       struct ceph_statx stx = {0};
+       struct UserPerm *uperm = NULL;
+       int ret = -1;
+
+       uperm = vfs_ceph_userperm_new(handle);
+       if (uperm == NULL) {
+               return -ENOMEM;
+       }
+       ret = ceph_ll_getattr(handle->data,
+                             iref->inode,
+                             &stx,
+                             SAMBA_STATX_ATTR_MASK,
+                             0,
+                             uperm);
+       if (ret == 0) {
+               smb_stat_from_ceph_statx(st, &stx);
+       }
+       vfs_ceph_userperm_del(uperm);
+       return ret;
+}
+
+/* Ceph Inode-refernce get/put wrappers */
+static int vfs_ceph_iget(const struct vfs_handle_struct *handle,
+                        uint64_t ino,
+                        const char *name,
+                        unsigned int flags,
+                        struct vfs_ceph_iref *iref)
+{
+       struct Inode *inode = NULL;
+       int ret = -1;
+
+       if (ino > CEPH_INO_ROOT) {
+               /* get-by-ino */
+               ret = vfs_ceph_ll_lookup_inode(handle, ino, &inode);
+               if (ret != 0) {
+                       return ret;
+               }
+       } else {
+               /* get-by-path */
+               struct ceph_statx stx = {.stx_ino = 0};
+
+               ret = vfs_ceph_ll_walk(handle,
+                                      name,
+                                      &inode,
+                                      &stx,
+                                      CEPH_STATX_INO,
+                                      flags);
+               if (ret != 0) {
+                       return ret;
+               }
+               ino = stx.stx_ino;
+       }
+       iref->inode = inode;
+       iref->ino = ino;
+       DBG_DEBUG("[CEPH] get-inode: %s ino=%" PRIu64 "\n", name, iref->ino);
+       return 0;
+}
+
+static int vfs_ceph_iget_by_fname(const struct vfs_handle_struct *handle,
+                                 const struct smb_filename *smb_fname,
+                                 struct vfs_ceph_iref *iref)
+{
+       const char *name = smb_fname->base_name;
+       const char *cwd = ceph_getcwd(handle->data);
+       int ret = -1;
+
+       if (!strcmp(name, cwd)) {
+               ret = vfs_ceph_iget(handle, 0, "./", 0, iref);
+       } else {
+               ret = vfs_ceph_iget(handle, 0, name, 0, iref);
+       }
+       return ret;
+}
+
+static void vfs_ceph_iput(const struct vfs_handle_struct *handle,
+                         struct vfs_ceph_iref *iref)
+{
+       if ((iref != NULL) && (iref->inode != NULL)) {
+               DBG_DEBUG("[CEPH] put-inode: ino=%" PRIu64 "\n", iref->ino);
+
+               ceph_ll_put(handle->data, iref->inode);
+               iref->inode = NULL;
+       }
+}
+
 /* Disk operations */
 
 static uint64_t vfs_ceph_disk_free(struct vfs_handle_struct *handle,
@@ -876,8 +1045,6 @@ static int vfs_ceph_fsync_recv(struct tevent_req *req,
        return 0;
 }
 
-#define SAMBA_STATX_ATTR_MASK  (CEPH_STATX_BASIC_STATS|CEPH_STATX_BTIME)
-
 static void init_stat_ex_from_ceph_statx(struct stat_ex *dst,
                                         const struct ceph_statx *stx)
 {
@@ -920,7 +1087,7 @@ static int vfs_ceph_stat(struct vfs_handle_struct *handle,
                        struct smb_filename *smb_fname)
 {
        int result = -1;
-       struct ceph_statx stx = { 0 };
+       struct vfs_ceph_iref iref = {0};
 
        DBG_DEBUG("[CEPH] stat(%p, %s)\n",
                  handle,
@@ -931,16 +1098,20 @@ static int vfs_ceph_stat(struct vfs_handle_struct *handle,
                return result;
        }
 
-       result = ceph_statx(handle->data, smb_fname->base_name, &stx,
-                               SAMBA_STATX_ATTR_MASK, 0);
-       DBG_DEBUG("[CEPH] statx(...) = %d\n", result);
-       if (result < 0) {
-               return status_code(result);
+       result = vfs_ceph_iget_by_fname(handle, smb_fname, &iref);
+       if (result != 0) {
+               goto out;
        }
 
-       init_stat_ex_from_ceph_statx(&smb_fname->st, &stx);
+       DBG_DEBUG("[CEPH] stat: ino=%" PRIu64 "\n", iref.ino);
+       result = vfs_ceph_ll_getattr(handle, &iref, &smb_fname->st);
+       if (result != 0) {
+               goto out;
+       }
        DBG_DEBUG("[CEPH] mode = 0x%x\n", smb_fname->st.st_ex_mode);
-       return result;
+out:
+       vfs_ceph_iput(handle, &iref);
+       return status_code(result);
 }
 
 static int vfs_ceph_fstat(struct vfs_handle_struct *handle,