* conflicting writes once the folio is grabbed and locked. It is passed a
* pointer to the fsdata cookie that gets returned to the VM to be passed to
* write_end. It is permitted to sleep. It should return 0 if the request
- * should go ahead; unlock the folio and return -EAGAIN to cause the folio to
- * be regot; or return an error.
+ * should go ahead or it may return an error. It may also unlock and put the
+ * folio, provided it sets ``*foliop`` to NULL, in which case a return of 0
+ * will cause the folio to be re-got and the process to be retried.
*
* The calling netfs must initialise a netfs context contiguous to the vfs
* inode before calling this.
if (ctx->ops->check_write_begin) {
/* Allow the netfs (eg. ceph) to flush conflicts. */
- ret = ctx->ops->check_write_begin(file, pos, len, folio, _fsdata);
+ ret = ctx->ops->check_write_begin(file, pos, len, &folio, _fsdata);
if (ret < 0) {
trace_netfs_failure(NULL, NULL, ret, netfs_fail_check_write_begin);
- if (ret == -EAGAIN)
- goto retry;
goto error;
}
+ if (!folio)
+ goto retry;
}
if (folio_test_uptodate(folio))
error_put:
netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
error:
- folio_unlock(folio);
- folio_put(folio);
+ if (folio) {
+ folio_unlock(folio);
+ folio_put(folio);
+ }
_leave(" = %d", ret);
return ret;
}