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nuttx-bb/apps/namedapp/binfs.c

597 lines
17 KiB
C

/****************************************************************************
* apps/namedapps/binfs.c
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/statfs.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/fs.h>
#include <nuttx/dirent.h>
#include "namedapp.h"
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_APPS_BINDIR)
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure represents the overall mountpoint state. An instance of this
* structure is retained as inode private data on each mountpoint that is
* mounted with a fat32 filesystem.
*/
struct binfs_state_s
{
sem_t bm_sem; /* Used to assume thread-safe access */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void binfs_semtake(struct binfs_state_s *bm);
static inline void binfs_semgive(struct binfs_state_s *bm);
static int binfs_open(FAR struct file *filep, const char *relpath,
int oflags, mode_t mode);
static int binfs_close(FAR struct file *filep);
static ssize_t binfs_read(FAR struct file *filep, char *buffer, size_t buflen);
static int binfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
static int binfs_opendir(struct inode *mountpt, const char *relpath,
struct fs_dirent_s *dir);
static int binfs_readdir(struct inode *mountpt, struct fs_dirent_s *dir);
static int binfs_rewinddir(struct inode *mountpt, struct fs_dirent_s *dir);
static int binfs_bind(FAR struct inode *blkdriver, const void *data,
void **handle);
static int binfs_unbind(void *handle, FAR struct inode **blkdriver);
static int binfs_statfs(struct inode *mountpt, struct statfs *buf);
static int binfs_stat(struct inode *mountpt, const char *relpath, struct stat *buf);
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/* 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 mountpt_operations binfs_operations =
{
binfs_open, /* open */
binfs_close, /* close */
binfs_read, /* read */
NULL, /* write */
NULL, /* seek */
binfs_ioctl, /* ioctl */
NULL, /* sync */
binfs_opendir, /* opendir */
NULL, /* closedir */
binfs_readdir, /* readdir */
binfs_rewinddir, /* rewinddir */
binfs_bind, /* bind */
binfs_unbind, /* unbind */
binfs_statfs, /* statfs */
NULL, /* unlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* rename */
binfs_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: binfs_semtake
****************************************************************************/
static void binfs_semtake(struct binfs_state_s *bm)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&bm->bm_sem) != 0)
{
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
ASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: binfs_semgive
****************************************************************************/
static inline void binfs_semgive(struct binfs_state_s *bm)
{
sem_post(&bm->bm_sem);
}
/****************************************************************************
* Name: binfs_open
****************************************************************************/
static int binfs_open(FAR struct file *filep, const char *relpath,
int oflags, mode_t mode)
{
struct binfs_state_s *bm;
int ret = -ENOSYS;
fvdbg("Open '%s'\n", relpath);
/* Sanity checks */
DEBUGASSERT(filep->f_priv == NULL && filep->f_inode != NULL);
/* mountpoint private data from the inode reference from the file
* structure
*/
bm = (struct binfs_state_s*)filep->f_inode->i_private;
DEBUGASSERT(bm != NULL);
/* BINFS is read-only. Any attempt to open with any kind of write
* access is not permitted.
*/
if ((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0)
{
fdbg("Only O_RDONLY supported\n");
ret = -EACCES;
}
/* Save open-specific state in filep->f_priv */
/* Opening of elements within the pseudo-file system is not yet supported */
return ret;
}
/****************************************************************************
* Name: binfs_close
****************************************************************************/
static int binfs_close(FAR struct file *filep)
{
struct binfs_state_s *bm;
int ret = -ENOSYS;
fvdbg("Closing\n");
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover the open file state from the struct file instance */
/* bf = filep->f_priv; */
/* Recover the file system state from the inode */
bm = filep->f_inode->i_private;
DEBUGASSERT(bm != NULL);
/* Free the open file state */
/* free(bf); */
filep->f_priv = NULL;
/* Since open() is not yet supported, neither is close(). */
return ret;
}
/****************************************************************************
* Name: binfs_read
****************************************************************************/
static ssize_t binfs_read(FAR struct file *filep, char *buffer, size_t buflen)
{
struct binfs_state_s *bm;
fvdbg("Read %d bytes from offset %d\n", buflen, filep->f_pos);
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover the open file state data from the struct file instance */
/* bf = filep->f_priv; */
/* Recover the file system state from the inode */
bm = filep->f_inode->i_private;
DEBUGASSERT(bm != NULL);
/* Since open is not yet supported, neither is reading */
return -ENOSYS;
}
/****************************************************************************
* Name: binfs_ioctl
****************************************************************************/
static int binfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
struct binfs_state_s *bm;
fvdbg("cmd: %d arg: %08lx\n", cmd, arg);
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover the open file state from the struct file instance */
/* bf = filep->f_priv; */
/* Recover the file system state from the inode */
bm = filep->f_inode->i_private;
DEBUGASSERT(bm != NULL);
/* No ioctl commands yet supported */
return -ENOTTY;
}
/****************************************************************************
* Name: binfs_opendir
*
* Description:
* Open a directory for read access
*
****************************************************************************/
static int binfs_opendir(struct inode *mountpt, const char *relpath,
struct fs_dirent_s *dir)
{
struct binfs_state_s *bm;
int ret;
fvdbg("relpath: \"%s\"\n", relpath ? relpath : "NULL");
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover the file system state from the inode instance */
bm = mountpt->i_private;
binfs_semtake(bm);
/* The requested directory must be the volume-relative "root" directory */
if (relpath && relpath[0] != '\0')
{
ret = -ENOENT;
goto errout_with_semaphore;
}
/* Set the index to the first entry */
dir->u.binfs.fb_index = 0;
ret = OK;
errout_with_semaphore:
binfs_semgive(bm);
return ret;
}
/****************************************************************************
* Name: binfs_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int binfs_readdir(struct inode *mountpt, struct fs_dirent_s *dir)
{
struct binfs_state_s *bm;
unsigned int index;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover the file system state from the inode instance */
bm = mountpt->i_private;
binfs_semtake(bm);
/* Have we reached the end of the directory */
index = dir->u.binfs.fb_index;
if (namedapps[index].name == NULL)
{
/* We signal the end of the directory by returning the
* special error -ENOENT
*/
fvdbg("Entry %d: End of directory\n", index);
ret = -ENOENT;
}
else
{
/* Save the filename and file type */
fvdbg("Entry %d: \"%s\"\n", index, namedapps[index].name);
dir->fd_dir.d_type = DTYPE_FILE;
strncpy(dir->fd_dir.d_name, namedapps[index].name, NAME_MAX+1);
/* The application list is terminated by an entry with a NULL name.
* Therefore, there is at least one more entry in the list.
*/
index++;
/* Set up the next directory entry offset. NOTE that we could use the
* standard f_pos instead of our own private fb_index.
*/
dir->u.binfs.fb_index = index;
ret = OK;
}
binfs_semgive(bm);
return ret;
}
/****************************************************************************
* Name: binfs_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int binfs_rewinddir(struct inode *mountpt, struct fs_dirent_s *dir)
{
struct binfs_state_s *bm;
fvdbg("Entry\n");
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover the file system state from the inode instance */
bm = mountpt->i_private;
binfs_semtake(bm);
dir->u.binfs.fb_index = 0;
binfs_semgive(bm);
return OK;
}
/****************************************************************************
* Name: binfs_bind
*
* Description: This implements a portion of the mount operation. This
* function allocates and initializes the mountpoint private data and
* binds the blockdriver inode to the filesystem private data. The final
* binding of the private data (containing the blockdriver) to the
* mountpoint is performed by mount().
*
****************************************************************************/
static int binfs_bind(FAR struct inode *blkdriver, const void *data,
void **handle)
{
struct binfs_state_s *bm;
fvdbg("Entry\n");
/* Create an instance of the mountpt state structure */
bm = (struct binfs_state_s *)zalloc(sizeof(struct binfs_state_s));
if (!bm)
{
fdbg("Failed to allocate mountpoint structure\n");
return -ENOMEM;
}
/* Initialize the allocated mountpt state structure. The filesystem is
* responsible for one reference ont the blkdriver inode and does not
* have to addref() here (but does have to release in ubind().
*/
sem_init(&bm->bm_sem, 0, 1); /* Initialize the semaphore that controls access */
/* Mounted! */
*handle = (void*)bm;
return OK;
}
/****************************************************************************
* Name: binfs_unbind
*
* Description: This implements the filesystem portion of the umount
* operation.
*
****************************************************************************/
static int binfs_unbind(void *handle, FAR struct inode **blkdriver)
{
struct binfs_state_s *bm = (struct binfs_state_s*)handle;
fvdbg("Entry\n");
#ifdef CONFIG_DEBUG
if (!bm)
{
return -EINVAL;
}
#endif
/* Check if there are sill any files opened on the filesystem. */
/* Release the mountpoint private data */
sem_destroy(&bm->bm_sem);
return OK;
}
/****************************************************************************
* Name: binfs_statfs
*
* Description: Return filesystem statistics
*
****************************************************************************/
static int binfs_statfs(struct inode *mountpt, struct statfs *buf)
{
struct binfs_state_s *bm;
fvdbg("Entry\n");
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
bm = mountpt->i_private;
binfs_semtake(bm);
/* Fill in the statfs info */
memset(buf, 0, sizeof(struct statfs));
buf->f_type = BINFS_MAGIC;
buf->f_bsize = 0;
buf->f_blocks = 0;
buf->f_bfree = 0;
buf->f_bavail = 0;
buf->f_namelen = NAME_MAX;
binfs_semgive(bm);
return OK;
}
/****************************************************************************
* Name: binfs_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int binfs_stat(struct inode *mountpt, const char *relpath, struct stat *buf)
{
struct binfs_state_s *bm;
int ret;
fvdbg("Entry\n");
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
bm = mountpt->i_private;
binfs_semtake(bm);
/* The requested directory must be the volume-relative "root" directory */
if (relpath && relpath[0] != '\0')
{
/* Check if there is a file with this name. */
if (namedapp_isavail(relpath) < 0)
{
ret = -ENOENT;
goto errout_with_semaphore;
}
/* It's a execute-only file name */
buf->st_mode = S_IFREG|S_IXOTH|S_IXGRP|S_IXUSR;
}
else
{
/* It's a read/execute-only directory name */
buf->st_mode = S_IFDIR|S_IROTH|S_IRGRP|S_IRUSR|S_IXOTH|S_IXGRP|S_IXUSR;
}
/* File/directory size, access block size */
buf->st_size = 0;
buf->st_blksize = 0;
buf->st_blocks = 0;
ret = OK;
errout_with_semaphore:
binfs_semgive(bm);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_APPS_BINDIR */