vfs_ceph_rgw: Return ENOATTR for non-existing xattr

In case of existing xattr, rgw_getxattrs() API executes callback and returns 0
on success. We then determine number of bytes to return from callback.

In case of non-existing xattr, rgw_getxattrs() API does not execute callback
but returns 0.

Upper layer expect NT_STATUS_OBJECT_NAME_NOT_FOUND in case of non-existing xattr.
Since we were returning 0, upper layer treats it as missing data and flags as error.

This fix allows module to handle this situation by returning -ENOATTR for
non-existing xattr, thereby providing correct information for upper layer.

Additional changes:
 - rgw_getxattrs() do not set errno, thus relevant handling is removed.
 - Added error handling for special names to get/set/rm xattr calls.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=16218

Signed-off-by: Vinit Agnihotri <vagnihot@redhat.com>
Reviewed-by: Shachar Sharon <ssharon@redhat.com>
Reviewed-by: Anoop C S <anoopcs@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
Autobuild-User(master): Anoop C S <anoopcs@samba.org>
Autobuild-Date(master): Tue Aug 11 06:06:14 UTC 2026 on atb-devel-224

diff --git a/source3/modules/vfs_ceph_rgw.c b/source3/modules/vfs_ceph_rgw.c
index d6b1837d3949972297d6b7c682bc5ea9aae455ee..fbbec98e3d4bfdeb292738f187898fee7e60f99a 100644 (file)
--- a/source3/modules/vfs_ceph_rgw.c
+++ b/source3/modules/vfs_ceph_rgw.c
@@ -90,6 +90,7 @@ struct vfs_ceph_rgw_getxattr_arg {
        int rc;
        char *val;
        size_t size;
+       bool cb_called;
 };
 
 struct vfs_ceph_rgw_lsxattr_arg {
@@ -902,6 +903,17 @@ static void prepare_xattr_list(rgw_xattrlist *attr_list,
        }
 }
 
+/*
+ * Callback for rgw_getxattrs() to get value for given attribute names.
+ *
+ * @param attrs: List of attributes received from RGW
+ * @param arg: Pointer to vfs_ceph_rgw_getxattr_arg structure
+ * @param flags: Callback flags (unused)
+ * @return: 0 to mark completion for callback.
+ *
+ * Output: value for attribute and size in bytes via callback argument.
+ *
+ */
 static int ceph_rgw_getxattr_cb(rgw_xattrlist *attr_list,
                                void *arg,
                                uint32_t flags)
@@ -910,7 +922,8 @@ static int ceph_rgw_getxattr_cb(rgw_xattrlist *attr_list,
                *cb_arg = (struct vfs_ceph_rgw_getxattr_arg *)arg;
        rgw_xattr *xattr = attr_list->xattrs;
 
-       if ((cb_arg->size != 0) && (cb_arg->size < xattr->val.len)) {
+       cb_arg->cb_called = true;
+       if (cb_arg->size < xattr->val.len) {
                cb_arg->rc = -ERANGE;
                return 0;
        }
@@ -943,6 +956,24 @@ static ssize_t vfs_ceph_rgw_fgetxattr(struct vfs_handle_struct *handle,
 
        DBG_DEBUG("[CEPH_RGW] fgetxattr: [%s] %s\n", fsp_str_dbg(fsp), name);
 
+       /*
+        * We do not support posix like handling to get current size of
+        * extended attribute from backend in case of size is mentioned as 0.
+        */
+       if (size == 0) {
+               DBG_DEBUG("[CEPH_RGW] No support to get size xattr\n");
+               rc = -ENOTSUP;
+               goto out;
+       }
+
+       if (is_special_name(fsp->fsp_name->base_name)) {
+               DBG_DEBUG(
+                       "[CEPH_RGW] Cannot perform op on special name [%s]\n",
+                       fsp_str_dbg(fsp));
+               rc = -EINVAL;
+               goto out;
+       }
+
        rc = vfs_ceph_rgw_fetch_fh(handle, fsp, &fh);
        if (rc != 0) {
                DBG_ERR("[CEPH_RGW] Unable to fetch handle\n");
@@ -951,7 +982,6 @@ static ssize_t vfs_ceph_rgw_fgetxattr(struct vfs_handle_struct *handle,
 
        prepare_xattr_list(&attr_list, discard_const(name), NULL, 0);
 
-       cb_arg.rc = 0;
        cb_arg.val = value;
        cb_arg.size = size;
 
@@ -962,23 +992,30 @@ static ssize_t vfs_ceph_rgw_fgetxattr(struct vfs_handle_struct *handle,
                           &cb_arg,
                           RGW_GETXATTR_FLAG_NONE);
 
-       if (rc < 0) {
-               int err = errno;
-               if (err == 0) {
-                       rc = -ENODATA;
-               } else {
-                       DBG_ERR("[CEPH_RGW] Error getting xattr. "
-                               "rc = %d errno = %d cbErr = %d\n",
-                               rc,
-                               err,
-                               cb_arg.rc);
-                       rc = -err;
-               }
+       if (rc < 0 || cb_arg.rc < 0) {
+               DBG_ERR("[CEPH_RGW] Error getting xattr. "
+                       "rc = %d cbErr = %d\n",
+                       rc,
+                       cb_arg.rc);
+               rc = (rc < 0) ? rc : cb_arg.rc;
                goto out;
        }
+
+       /*
+        * API returns 0 on success and callback serves to indicate
+        * number of bytes to return.
+        */
        rc = cb_arg.rc;
-       if (rc < 0) {
-               DBG_ERR("[CEPH_RGW] Error getting xattr. Err=%d\n", cb_arg.rc);
+
+       /*
+        * In case of requested xattr is not found,
+        * API returns 0, and callback is not called.
+        * Therefore we treat this case as  -ENOATTR.
+        */
+       if (rc == 0 && !cb_arg.cb_called) {
+               DBG_DEBUG("[CEPH_RGW] xattr %s not found.\n", name);
+               rc = -ENOATTR;
+               /* fall through */
        }
 out:
        DBG_DEBUG("[CEPH_RGW] fgetxattr(...) = %d\n", rc);
@@ -1008,6 +1045,14 @@ static int vfs_ceph_rgw_fsetxattr(struct vfs_handle_struct *handle,
 
        DBG_DEBUG("[CEPH_RGW] fsetxattr [%s] %s\n", fsp_str_dbg(fsp), name);
 
+       if (is_special_name(fsp->fsp_name->base_name)) {
+               DBG_DEBUG(
+                       "[CEPH_RGW] Cannot perform op on special name [%s]\n",
+                       fsp_str_dbg(fsp));
+               rc = -EINVAL;
+               goto out;
+       }
+
        rc = vfs_ceph_rgw_fetch_fh(handle, fsp, &fh);
        if (rc != 0) {
                DBG_ERR("[CEPH_RGW] Unable to fetch handle\n");
@@ -2040,6 +2085,14 @@ static int vfs_ceph_rgw_fremovexattr(struct vfs_handle_struct *handle,
                                struct vfs_ceph_rgw_config,
                                goto out);
 
+       if (is_special_name(fsp->fsp_name->base_name)) {
+               DBG_DEBUG(
+                       "[CEPH_RGW] Cannot perform op on special name [%s]\n",
+                       fsp_str_dbg(fsp));
+               rc = -EINVAL;
+               goto out;
+       }
+
        rc = vfs_ceph_rgw_fetch_fh(handle, fsp, &fh);
        if (rc != 0) {
                DBG_ERR("[CEPH_RGW] Unable to fetch handle\n");