incubator-nuttx/fs/mount/fs_procfs_mount.c

581 lines
16 KiB
C

/****************************************************************************
* fs/mount/fs_procfs_mount.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 <nuttx/compiler.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/statfs.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdarg.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/fs/fs.h>
#include <nuttx/fs/procfs.h>
#include "mount/mount.h"
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS)
#if !defined(CONFIG_FS_PROCFS_EXCLUDE_MOUNT) || \
!defined(CONFIG_FS_PROCFS_EXCLUDE_BLOCKS) || \
!defined(CONFIG_FS_PROCFS_EXCLUDE_USAGE)
/****************************************************************************
* 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 MOUNT_LINELEN 64
/****************************************************************************
* Private Types
****************************************************************************/
enum mount_file_e
{
FS_MOUNT_FILE = 0, /* /proc/fs/mount */
FS_BLOCKS_FILE, /* /proc/fs/blocks */
FS_USAGE_FILE, /* /proc/fs/usage */
};
struct mount_file_s
{
struct procfs_file_s base; /* Base open file structure */
uint8_t id; /* See enum mount_file_e */
char line[MOUNT_LINELEN]; /* Pre-allocated buffer for formatted lines */
};
/* The structure is used when traversing routing tables */
struct mount_info_s
{
FAR char *line; /* Intermediate line buffer pointer */
FAR char *buffer; /* User buffer */
size_t linelen; /* Size of the intermediate buffer */
size_t buflen; /* Size of the user buffer */
size_t remaining; /* Bytes remaining in user buffer */
size_t totalsize; /* Accumulated size of the copy */
off_t offset; /* Skip offset */
bool header; /* True: header has been generated */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Helpers */
static void mount_sprintf(FAR struct mount_info_s *info,
FAR const char *fmt, ...) printf_like(2, 3);
#ifndef CONFIG_FS_PROCFS_EXCLUDE_MOUNT
static int mount_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg);
#endif
#ifndef CONFIG_FS_PROCFS_EXCLUDE_BLOCKS
static int blocks_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg);
#endif
#ifndef CONFIG_FS_PROCFS_EXCLUDE_USAGE
static int usage_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg);
#endif
/* File system methods */
static int mount_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int mount_close(FAR struct file *filep);
static ssize_t mount_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int mount_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int mount_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_mount_operations =
{
mount_open, /* open */
mount_close, /* close */
mount_read, /* read */
NULL, /* write */
NULL, /* poll */
mount_dup, /* dup */
NULL, /* opendir */
NULL, /* closedir */
NULL, /* readdir */
NULL, /* rewinddir */
mount_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mount_sprintf
*
* Description:
* Generate otuput from fs/mount, fs/blocks, or fs/usage, file read.
*
****************************************************************************/
static void mount_sprintf(FAR struct mount_info_s *info,
FAR const char *fmt, ...)
{
size_t linesize;
size_t copysize;
va_list ap;
/* Print the format and data to a line buffer */
va_start(ap, fmt);
linesize = vsnprintf(info->line, info->linelen, fmt, ap);
va_end(ap);
/* Copy the line buffer to the user buffer */
copysize = procfs_memcpy(info->line, linesize,
info->buffer, info->remaining,
&info->offset);
/* Update counts and pointers */
info->totalsize += copysize;
info->buffer += copysize;
info->remaining -= copysize;
}
/****************************************************************************
* Name: mount_entry
*
* Description:
* Output one fs/mount entry
*
* Format:
* <mountpoint> type <type>
*
****************************************************************************/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_MOUNT
static int mount_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg)
{
FAR struct mount_info_s *info = (FAR struct mount_info_s *)arg;
FAR const char *fstype;
DEBUGASSERT(mountpoint != NULL && statbuf != NULL && info != NULL);
/* Get the file system type */
fstype = fs_gettype(statbuf);
/* Generate mount list one line at a time */
mount_sprintf(info, " %s type %s\n", mountpoint, fstype);
return (info->totalsize >= info->buflen) ? 1 : 0;
}
#endif
/****************************************************************************
* Name: blocks_entry
*
* Description:
* Output one fs/blocks entry
*
* Format:
* <mountpoint> type <type>
*
****************************************************************************/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_BLOCKS
static int blocks_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg)
{
FAR struct mount_info_s *info = (FAR struct mount_info_s *)arg;
DEBUGASSERT(mountpoint != NULL && statbuf != NULL && info != NULL);
/* Have we generated the header yet? */
if (!info->header)
{
mount_sprintf(info,
" Block Number\n");
mount_sprintf(info,
" Size Blocks Used Available Mounted on\n");
info->header = true;
}
/* Generate blocks list one line at a time */
mount_sprintf(info, "%6zu %10" PRIuOFF " %10" PRIuOFF
" %10" PRIuOFF " %s\n",
statbuf->f_bsize, statbuf->f_blocks,
statbuf->f_blocks - statbuf->f_bavail, statbuf->f_bavail,
mountpoint);
return (info->totalsize >= info->buflen) ? 1 : 0;
}
#endif
/****************************************************************************
* Name: blocks_entry
*
* Description:
* Output one fs/usage entry
*
* Format:
* <mountpoint> type <type>
*
****************************************************************************/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_USAGE
static int usage_entry(FAR const char *mountpoint,
FAR struct statfs *statbuf, FAR void *arg)
{
FAR struct mount_info_s *info = (FAR struct mount_info_s *)arg;
FAR const char *fstype;
fsblkcnt_t size;
fsblkcnt_t used;
fsblkcnt_t free;
int which;
char sizelabel;
char freelabel;
char usedlabel;
static const char labels[5] =
{
'B', 'K', 'M', 'G', 'T'
};
DEBUGASSERT(mountpoint != NULL && statbuf != NULL && info != NULL);
/* Have we generated the header yet? */
if (!info->header)
{
mount_sprintf(info,
" Filesystem Size Used Available Mounted on\n");
info->header = true;
}
/* Get the file system type */
fstype = fs_gettype(statbuf);
size = statbuf->f_bsize * statbuf->f_blocks;
free = statbuf->f_bsize * statbuf->f_bavail;
used = size - free;
/* Find the label for size */
which = 0;
while (size >= 9999 || ((size & 0x3ff) == 0 && size != 0))
{
which++;
size >>= 10;
}
sizelabel = labels[which];
/* Find the label for free */
which = 0;
while (free >= 9999 || ((free & 0x3ff) == 0 && free != 0))
{
which++;
free >>= 10;
}
freelabel = labels[which];
/* Find the label for used */
which = 0;
while (used >= 9999 || ((used & 0x3ff) == 0 && used != 0))
{
which++;
used >>= 10;
}
usedlabel = labels[which];
/* Generate usage list one line at a time */
mount_sprintf(info,
" %-10s %8" PRIuOFF "%c %8" PRIuOFF "%c %8" PRIuOFF "%c %s\n",
fstype, size, sizelabel, used, usedlabel, free, freelabel, mountpoint);
return (info->totalsize >= info->buflen) ? 1 : 0;
}
#endif
/****************************************************************************
* Name: mount_open
****************************************************************************/
static int mount_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
FAR struct mount_file_s *procfile;
uint8_t id;
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;
}
/* "fs/mount", "fs/block", and "fs/usage" are the only acceptable values
* for the relpath.
*/
#ifndef CONFIG_FS_PROCFS_EXCLUDE_MOUNT
if (strcmp(relpath, "fs/mount") == 0)
{
id = FS_MOUNT_FILE;
}
#endif
#ifndef CONFIG_FS_PROCFS_EXCLUDE_BLOCKS
else if (strcmp(relpath, "fs/blocks") == 0)
{
id = FS_BLOCKS_FILE;
}
#endif
else if (strcmp(relpath, "fs/usage") == 0)
{
id = FS_USAGE_FILE;
}
else
{
ferr("ERROR: relpath is '%s'\n", relpath);
return -ENOENT;
}
/* Allocate a container to hold the task and node selection */
procfile = (FAR struct mount_file_s *)
kmm_zalloc(sizeof(struct mount_file_s));
if (!procfile)
{
ferr("ERROR: Failed to allocate file container\n");
return -ENOMEM;
}
/* Save the file ID */
procfile->id = id;
/* Save the open-specific state in filep->f_priv */
filep->f_priv = (FAR void *)procfile;
return OK;
}
/****************************************************************************
* Name: mount_close
****************************************************************************/
static int mount_close(FAR struct file *filep)
{
FAR struct mount_file_s *procfile;
/* Recover our private data from the struct file instance */
procfile = (FAR struct mount_file_s *)filep->f_priv;
DEBUGASSERT(procfile);
/* Release the file container structure */
kmm_free(procfile);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: mount_read
****************************************************************************/
static ssize_t mount_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct mount_file_s *procfile;
struct mount_info_s info;
foreach_mountpoint_t handler;
ssize_t ret;
finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
procfile = (FAR struct mount_file_s *)filep->f_priv;
DEBUGASSERT(procfile);
/* Provide the requested data */
memset(&info, 0, sizeof(struct mount_info_s));
info.line = procfile->line;
info.buffer = buffer;
info.linelen = MOUNT_LINELEN;
info.buflen = buflen;
info.remaining = buflen;
info.offset = filep->f_pos;
info.header = false;
switch (procfile->id)
{
#ifndef CONFIG_FS_PROCFS_EXCLUDE_MOUNT
case FS_MOUNT_FILE: /* /proc/fs/mount */
handler = mount_entry;
break;
#endif
#ifndef CONFIG_FS_PROCFS_EXCLUDE_BLOCKS
case FS_BLOCKS_FILE: /* /proc/fs/blocks */
handler = blocks_entry;
break;
#endif
#ifndef CONFIG_FS_PROCFS_EXCLUDE_USAGE
case FS_USAGE_FILE: /* /proc/fs/usage */
handler = usage_entry;
break;
#endif
default:
DEBUGPANIC();
return -EINVAL;
}
/* Generate each entry in the routing table */
foreach_mountpoint(handler, &info);
ret = info.totalsize;
/* Update the file offset */
if (ret > 0)
{
filep->f_pos += ret;
}
return ret;
}
/****************************************************************************
* Name: mount_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int mount_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct mount_file_s *oldfile;
FAR struct mount_file_s *newfile;
finfo("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldfile = (FAR struct mount_file_s *)oldp->f_priv;
DEBUGASSERT(oldfile);
/* Allocate a new container to hold the task and node selection */
newfile = (FAR struct mount_file_s *)
kmm_malloc(sizeof(struct mount_file_s));
if (!newfile)
{
ferr("ERROR: Failed to allocate file container\n");
return -ENOMEM;
}
/* The copy the file information from the old container to the new */
memcpy(newfile, oldfile, sizeof(struct mount_file_s));
/* Save the new container in the new file structure */
newp->f_priv = (FAR void *)newfile;
return OK;
}
/****************************************************************************
* Name: mount_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int mount_stat(const char *relpath, struct stat *buf)
{
memset(buf, 0, sizeof(struct stat));
buf->st_mode = S_IFREG | S_IROTH | S_IRGRP | S_IRUSR;
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
#endif /* !CONFIG_FS_PROCFS_EXCLUDE_MOUNT || \
* !CONFIG_FS_PROCFS_EXCLUDE_BLOCKS || \
* !CONFIG_FS_PROCFS_EXCLUDE_USAGE */
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */