jlaitine commented on code in PR #8109: URL: https://github.com/apache/nuttx/pull/8109#discussion_r1072851767
########## fs/shm/shmfs.c: ########## @@ -0,0 +1,377 @@ +/**************************************************************************** + * fs/shm/shmfs.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <assert.h> + +#include <nuttx/fs/ioctl.h> +#include <nuttx/mm/map.h> + +#if defined (CONFIG_BUILD_KERNEL) +#include <nuttx/arch.h> +#include <nuttx/pgalloc.h> +#include <nuttx/sched.h> +#endif + +#include "shm/shmfs.h" +#include "inode/inode.h" + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +static int shmfs_close(FAR struct file *filep); +static ssize_t shmfs_read(FAR struct file *filep, FAR char *buffer, + size_t buflen); +static ssize_t shmfs_write(FAR struct file *filep, FAR const char *buffer, + size_t buflen); +static int shmfs_truncate(FAR struct file *filep, off_t length); + +#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS +static int shmfs_unlink(FAR struct inode *inode); +#endif + +static int shmfs_mmap(FAR struct file *filep, + FAR struct mm_map_entry_s *entry); +static int shmfs_munmap(FAR struct task_group_s *group, + FAR struct mm_map_entry_s *entry, + FAR void *start, + size_t length); + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +const struct file_operations shmfs_operations = +{ + NULL, /* open */ + shmfs_close, /* close */ + shmfs_read, /* read */ + shmfs_write, /* write */ + NULL, /* seek */ + NULL, /* ioctl */ + shmfs_mmap, /* mmap */ + shmfs_truncate, /* truncate */ + NULL, /* poll */ +#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS + shmfs_unlink /* unlink */ +#endif +}; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: shmfs_read + ****************************************************************************/ + +static ssize_t shmfs_read(FAR struct file *filep, FAR char *buffer, + size_t buflen) +{ + return -ENOSYS; +} + +/**************************************************************************** + * Name: shmfs_write + ****************************************************************************/ + +static ssize_t shmfs_write(FAR struct file *filep, FAR const char *buffer, + size_t buflen) +{ + return -ENOSYS; +} + +/**************************************************************************** + * Name: shmfs_release + ****************************************************************************/ + +static int shmfs_release(FAR struct inode *inode) +{ + /* If the file has been unlinked previously, delete the contents. + * The inode is released after this call, hence checking if i_crefs <= 1. + */ + + int ret = inode_lock(); + if (ret >= 0) + { + if (inode->i_parent == NULL && + inode->i_crefs <= 1) + { + shmfs_free_object(inode->i_private); + inode->i_private = NULL; + ret = OK; + } + + inode_unlock(); + } + + return ret; +} + +/**************************************************************************** + * Name: shmfs_close + ****************************************************************************/ + +static int shmfs_close(FAR struct file *filep) +{ + /* Release the shmfs object. The object gets deleted if no-one has + * reference to it (either mmap or open file) and the object has been + * unlinked + */ + + return shmfs_release(filep->f_inode); +} + +/**************************************************************************** + * Name: shmfs_truncate + ****************************************************************************/ + +static int shmfs_truncate(FAR struct file *filep, off_t length) +{ + FAR struct shmfs_object_s *object; + int ret; + + if (length == 0) + { + return -EINVAL; + } + + ret = inode_lock(); + if (ret >= 0) + { + object = filep->f_inode->i_private; + if (!object) + { + filep->f_inode->i_private = shmfs_alloc_object(length); + if (!filep->f_inode->i_private) + { + ret = -EFAULT; + } + } + else if (object->length != length) + { + /* This doesn't support resize */ + + ret = -EINVAL; + } + + inode_unlock(); + } + + return ret; +} + +/**************************************************************************** + * Name: shmfs_unlink + ****************************************************************************/ + +#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS +static int shmfs_unlink(FAR struct inode *inode) +{ + int ret = inode_lock(); + + if (ret >= 0) + { + if (inode->i_crefs <= 1) + { + shmfs_free_object(inode->i_private); + inode->i_private = NULL; + ret = OK; + } + + inode_unlock(); + } + + return ret; +} +#endif + +/**************************************************************************** + * Name: shmfs_map_object + ****************************************************************************/ + +static int shmfs_map_object(FAR struct shmfs_object_s *object, + FAR void **vaddr) +{ + int ret = OK; + +#ifdef CONFIG_BUILD_KERNEL + /* Map the physical pages of the shm object with MMU. */ + + FAR struct tcb_s *tcb = nxsched_self(); + FAR struct task_group_s *group = tcb->group; + FAR uintptr_t *pages = Review Comment: I removed the alignment from all of those instead, as they have been also removed in all the other places in this file. -- This is an automated message from the Apache Git Service. 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