incubator-nuttx/fs/procfs/fs_procfsiobinfo.c

288 lines
8.9 KiB
C

/****************************************************************************
* fs/procfs/fs_procfsiobinfo.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 <nuttx/config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mm/iob.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/procfs.h>
#include "fs_heap.h"
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS) && \
defined(CONFIG_MM_IOB) && !defined(CONFIG_FS_PROCFS_EXCLUDE_IOBINFO)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Determines the size of an intermediate buffer that must be large enough
* to handle the longest line generated by this logic.
*/
#define IOBINFO_LINELEN 80
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes one open "file" */
struct iobinfo_file_s
{
struct procfs_file_s base; /* Base open file structure */
unsigned int linesize; /* Number of valid characters in line[] */
char line[IOBINFO_LINELEN]; /* Pre-allocated buffer for formatted lines */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* File system methods */
static int iobinfo_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int iobinfo_close(FAR struct file *filep);
static ssize_t iobinfo_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int iobinfo_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int iobinfo_stat(FAR const char *relpath, FAR struct stat *buf);
/****************************************************************************
* Public Data
****************************************************************************/
/* See fs_mount.c -- this structure is explicitly externed there.
* We use the old-fashioned kind of initializers so that this will compile
* with any compiler.
*/
const struct procfs_operations g_iobinfo_operations =
{
iobinfo_open, /* open */
iobinfo_close, /* close */
iobinfo_read, /* read */
NULL, /* write */
NULL, /* poll */
iobinfo_dup, /* dup */
NULL, /* opendir */
NULL, /* closedir */
NULL, /* readdir */
NULL, /* rewinddir */
iobinfo_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: iobinfo_open
****************************************************************************/
static int iobinfo_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
FAR struct iobinfo_file_s *procfile;
finfo("Open '%s'\n", relpath);
/* PROCFS is read-only. Any attempt to open with any kind of write
* access is not permitted.
*
* REVISIT: Write-able proc files could be quite useful.
*/
if ((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0)
{
ferr("ERROR: Only O_RDONLY supported\n");
return -EACCES;
}
/* Allocate a container to hold the file attributes */
procfile = (FAR struct iobinfo_file_s *)
fs_heap_zalloc(sizeof(struct iobinfo_file_s));
if (!procfile)
{
ferr("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* Save the attributes as the open-specific state in filep->f_priv */
filep->f_priv = (FAR void *)procfile;
return OK;
}
/****************************************************************************
* Name: iobinfo_close
****************************************************************************/
static int iobinfo_close(FAR struct file *filep)
{
FAR struct iobinfo_file_s *procfile;
/* Recover our private data from the struct file instance */
procfile = (FAR struct iobinfo_file_s *)filep->f_priv;
DEBUGASSERT(procfile);
/* Release the file attributes structure */
fs_heap_free(procfile);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: iobinfo_read
****************************************************************************/
static ssize_t iobinfo_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct iobinfo_file_s *iobfile;
FAR struct iob_stats_s stats;
size_t linesize;
size_t copysize;
size_t totalsize;
off_t offset;
finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
DEBUGASSERT(buffer != NULL && buflen > 0);
offset = filep->f_pos;
/* Recover our private data from the struct file instance */
iobfile = (FAR struct iobinfo_file_s *)filep->f_priv;
DEBUGASSERT(iobfile);
/* The first line is the headers */
linesize = procfs_snprintf(iobfile->line, IOBINFO_LINELEN,
"%10s%10s%10s%10s\n",
"ntotal", "nfree", "nwait", "nthrottle");
copysize = procfs_memcpy(iobfile->line, linesize, buffer, buflen,
&offset);
totalsize = copysize;
buffer += copysize;
buflen -= copysize;
/* The second line is the usage statistics */
iob_getstats(&stats);
linesize = procfs_snprintf(iobfile->line, IOBINFO_LINELEN,
"%10d%10d%10d%10d\n",
stats.ntotal, stats.nfree,
stats.nwait, stats.nthrottle);
copysize = procfs_memcpy(iobfile->line, linesize, buffer, buflen,
&offset);
totalsize += copysize;
/* Update the file offset */
filep->f_pos += totalsize;
return totalsize;
}
/****************************************************************************
* Name: iobinfo_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int iobinfo_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct iobinfo_file_s *oldattr;
FAR struct iobinfo_file_s *newattr;
finfo("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldattr = (FAR struct iobinfo_file_s *)oldp->f_priv;
DEBUGASSERT(oldattr);
/* Allocate a new container to hold the task and attribute selection */
newattr = (FAR struct iobinfo_file_s *)
fs_heap_malloc(sizeof(struct iobinfo_file_s));
if (!newattr)
{
ferr("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* The copy the file attributes from the old attributes to the new */
memcpy(newattr, oldattr, sizeof(struct iobinfo_file_s));
/* Save the new attributes in the new file structure */
newp->f_priv = (FAR void *)newattr;
return OK;
}
/****************************************************************************
* Name: iobinfo_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int iobinfo_stat(FAR const char *relpath, FAR struct stat *buf)
{
/* "iobinfo" is the name for a read-only file */
memset(buf, 0, sizeof(struct stat));
buf->st_mode = S_IFREG | S_IROTH | S_IRGRP | S_IRUSR;
return OK;
}
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS &&
* CONFIG_MM_IOB && !CONFIG_FS_PROCFS_EXCLUDE_IOBINFO */