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nuttx/fs/romfs/fs_romfs.c
patacongo f796d1dff6 Use SEC_NSECTOR macro 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@921 42af7a65-404d-4744-a932-0658087f49c3
2008-09-12 22:28:29 +00:00

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26 KiB
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/****************************************************************************
* rm/romfs/fs_romfs.h
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* References: Linux/Documentation/filesystems/romfs.txt
*
* 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 <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/fs.h>
#include <nuttx/ioctl.h>
#include "fs_romfs.h"
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int romfs_open(FAR struct file *filep, const char *relpath,
int oflags, mode_t mode);
static int romfs_close(FAR struct file *filep);
static ssize_t romfs_read(FAR struct file *filep, char *buffer, size_t buflen);
static off_t romfs_seek(FAR struct file *filep, off_t offset, int whence);
static int romfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
static int romfs_opendir(struct inode *mountpt, const char *relpath,
struct internal_dir_s *dir);
static int romfs_readdir(struct inode *mountpt, struct internal_dir_s *dir);
static int romfs_rewinddir(struct inode *mountpt, struct internal_dir_s *dir);
static int romfs_bind(FAR struct inode *blkdriver, const void *data,
void **handle);
static int romfs_unbind(void *handle, FAR struct inode **blkdriver);
static int romfs_statfs(struct inode *mountpt, struct statfs *buf);
static int romfs_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 romfs_operations =
{
romfs_open, /* open */
romfs_close, /* close */
romfs_read, /* read */
NULL, /* write */
romfs_seek, /* seek */
romfs_ioctl, /* ioctl */
NULL, /* sync */
romfs_opendir, /* opendir */
NULL, /* closedir */
romfs_readdir, /* readdir */
romfs_rewinddir, /* rewinddir */
romfs_bind, /* bind */
romfs_unbind, /* unbind */
romfs_statfs, /* statfs */
NULL, /* unlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* rename */
romfs_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: romfs_open
****************************************************************************/
static int romfs_open(FAR struct file *filep, const char *relpath,
int oflags, mode_t mode)
{
struct romfs_dirinfo_s dirinfo;
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv == NULL && filep->f_inode != NULL);
/* mountpoint private data from the inode reference from the file
* structure
*/
rm = (struct romfs_mountpt_s*)filep->f_inode->i_private;
DEBUGASSERT(rm != NULL);
/* Check if the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* ROMFS 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)
{
ret = -EACCES;
goto errout_with_semaphore;
}
/* Initialize the directory info structure */
memset(&dirinfo, 0, sizeof(struct romfs_dirinfo_s));
/* Locate the directory entry for this path */
ret = romfs_finddirentry(rm, &dirinfo, relpath);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* The full path exists -- but is the final component a file
* or a directory?
*/
if (IS_DIRECTORY(dirinfo.rd_next))
{
/* It is a directory */
ret = -EISDIR;
goto errout_with_semaphore;
}
#ifdef CONFIG_FILE_MODE
# warning "Missing check for privileges based on inode->i_mode"
#endif
/* Create an instance of the file private date to describe the opened
* file.
*/
rf = (struct romfs_file_s *)zalloc(sizeof(struct romfs_file_s));
if (!rf)
{
ret = -ENOMEM;
goto errout_with_semaphore;
}
/* Initialize the file private data (only need to initialize
* non-zero elements)
*/
rf->rf_open = TRUE;
rf->rf_size = dirinfo.rd_size;
/* Get the start of the file data */
ret = romfs_datastart(rm, dirinfo.rd_dir.fr_curroffset,
&rf->rf_startoffset);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Configure buffering to support access to this file */
ret = romfs_fileconfigure(rm, rf);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Attach the private date to the struct file instance */
filep->f_priv = rf;
/* Then insert the new instance into the mountpoint structure.
* It needs to be there (1) to handle error conditions that effect
* all files, and (2) to inform the umount logic that we are busy
* (but a simple reference count could have done that).
*/
rf->rf_next = rm->rm_head;
rm->rm_head = rf->rf_next;
romfs_semgive(rm);
return OK;
/* Error exits */
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_close
****************************************************************************/
static int romfs_close(FAR struct file *filep)
{
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
int ret = OK;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover our private data from the struct file instance */
rf = filep->f_priv;
rm = filep->f_inode->i_private;
DEBUGASSERT(rm != NULL);
/* Do not check if the mount is healthy. We must support closing of
* the file even when there is healthy mount.
*/
/* Deallocate the memory structures created when the open method
* was called.
*
* Free the sector buffer that was used to manage partial sector
* accesses.
*/
if (!rm->rm_xipbase && rf->rf_buffer)
{
free(rf->rf_buffer);
}
/* Then free the file structure itself. */
free(rf);
filep->f_priv = NULL;
return ret;
}
/****************************************************************************
* Name: romfs_read
****************************************************************************/
static ssize_t romfs_read(FAR struct file *filep, char *buffer, size_t buflen)
{
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
unsigned int bytesread;
unsigned int readsize;
unsigned int nsectors;
uint32 offset;
size_t bytesleft;
off_t sector;
ubyte *userbuffer = (ubyte*)buffer;
int sectorndx;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover our private data from the struct file instance */
rf = filep->f_priv;
rm = filep->f_inode->i_private;
DEBUGASSERT(rm != NULL);
/* Make sure that the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* Get the number of bytes left in the file */
bytesleft = rf->rf_size - filep->f_pos;
/* Truncate read count so that it does not exceed the number
* of bytes left in the file.
*/
if (buflen > bytesleft)
{
buflen = bytesleft;
}
/* Loop until either (1) all data has been transferred, or (2) an
* error occurs.
*/
readsize = 0;
while (buflen > 0)
{
/* Get the first sector and index to read from. */
offset = rf->rf_startoffset + filep->f_pos;
sector = SEC_NSECTORS(rm, offset);
sectorndx = offset & SEC_NDXMASK(rm);
bytesread = 0;
/* Check if the user has provided a buffer large enough to
* hold one or more complete sectors -AND- the read is
* aligned to a sector boundary.
*/
nsectors = SEC_NSECTORS(rm, buflen);
if (nsectors > 0 && sectorndx == 0)
{
/* Read maximum contiguous sectors directly to the user's
* buffer without using our tiny read buffer.
*/
/* Read all of the sectors directly into user memory */
ret = romfs_hwread(rm, userbuffer, sector, nsectors);
if (ret < 0)
{
goto errout_with_semaphore;
}
sector += nsectors;
bytesread = nsectors * rm->rm_hwsectorsize;
}
else
{
/* We are reading a partial sector. First, read the whole sector
* into the file data buffer. This is a caching buffer so if
* it is already there then all is well.
*/
ret = romfs_filecacheread(rm, rf, sector);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Copy the partial sector into the user buffer */
bytesread = rm->rm_hwsectorsize - sectorndx;
if (bytesread > buflen)
{
/* We will not read to the end of the buffer */
bytesread = buflen;
}
else
{
/* We will read to the end of the buffer (or beyond) */
sector++;
}
memcpy(userbuffer, &rf->rf_buffer[sectorndx], bytesread);
}
/* Set up for the next sector read */
userbuffer += bytesread;
filep->f_pos += bytesread;
readsize += bytesread;
buflen -= bytesread;
}
romfs_semgive(rm);
return readsize;
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_seek
****************************************************************************/
static off_t romfs_seek(FAR struct file *filep, off_t offset, int whence)
{
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
ssize_t position;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover our private data from the struct file instance */
rf = filep->f_priv;
rm = filep->f_inode->i_private;
DEBUGASSERT(rm != NULL);
/* Map the offset according to the whence option */
switch (whence)
{
case SEEK_SET: /* The offset is set to offset bytes. */
position = offset;
break;
case SEEK_CUR: /* The offset is set to its current location plus
* offset bytes. */
position = offset + filep->f_pos;
break;
case SEEK_END: /* The offset is set to the size of the file plus
* offset bytes. */
position = offset + rf->rf_size;
break;
default:
return -EINVAL;
}
/* Make sure that the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* Limit positions to the end of the file. */
if (position > rf->rf_size)
{
/* Otherwise, the position is limited to the file size */
position = rf->rf_size;
}
/* Set file position and return success */
filep->f_pos = position;
romfs_semgive(rm);
return OK;
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_ioctl
****************************************************************************/
static int romfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
FAR void **ppv = (FAR void**)arg;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover our private data from the struct file instance */
rf = filep->f_priv;
rm = filep->f_inode->i_private;
DEBUGASSERT(rm != NULL);
/* Only one ioctl command is supported */
if (cmd == FIOC_MMAP && rm->rm_xipbase && ppv)
{
/* Return the address on the media corresponding to the start of
* the file.
*/
*ppv = (void*)(rm->rm_xipbase + rf->rf_startoffset);
return OK;
}
return -ENOTTY;
}
/****************************************************************************
* Name: romfs_opendir
*
* Description:
* Open a directory for read access
*
****************************************************************************/
static int romfs_opendir(struct inode *mountpt, const char *relpath,
struct internal_dir_s *dir)
{
struct romfs_mountpt_s *rm;
struct romfs_dirinfo_s dirinfo;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
rm = mountpt->i_private;
/* Make sure that the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* Find the requested directory */
ret = romfs_finddirentry(rm, &dirinfo, relpath);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Verify that it is some kind of directory */
if (!IS_DIRECTORY(dirinfo.rd_next))
{
/* The entry is not a directory */
ret = -ENOTDIR;
goto errout_with_semaphore;
}
/* The entry is a directory */
memcpy(&dir->u.romfs, &dirinfo.rd_dir, sizeof(struct fs_romfsdir_s));
romfs_semgive(rm);
return OK;
errout_with_semaphore:
romfs_semgive(rm);
return ERROR;
}
/****************************************************************************
* Name: romfs_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int romfs_readdir(struct inode *mountpt, struct internal_dir_s *dir)
{
struct romfs_mountpt_s *rm;
uint32 linkoffset;
uint32 next;
uint32 info;
uint32 size;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
rm = mountpt->i_private;
/* Make sure that the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* Loop, skipping over unsupported items in the file system */
for (;;)
{
/* Have we reached the end of the directory */
if (!dir->u.romfs.fr_curroffset)
{
/* We signal the end of the directory by returning the
* special error -ENOENT
*/
ret = -ENOENT;
goto errout_with_semaphore;
}
/* Parse the directory entry */
ret = romfs_parsedirentry(rm, dir->u.romfs.fr_curroffset, &linkoffset,
&next, &info, &size);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Save the filename */
ret = romfs_parsefilename(rm, dir->u.romfs.fr_curroffset, dir->fd_dir.d_name);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Set up the next directory entry offset */
dir->u.romfs.fr_curroffset = next & RFNEXT_OFFSETMASK;
/* Check the file type */
if (IS_DIRECTORY(next))
{
dir->fd_dir.d_type = DTYPE_DIRECTORY;
break;
}
else if (IS_FILE(next))
{
dir->fd_dir.d_type = DTYPE_FILE;
break;
}
}
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int romfs_rewinddir(struct inode *mountpt, struct internal_dir_s *dir)
{
struct romfs_mountpt_s *rm;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
rm = mountpt->i_private;
/* Make sure that the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret == OK)
{
dir->u.romfs.fr_curroffset = dir->u.romfs.fr_firstoffset;
}
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_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 romfs_bind(FAR struct inode *blkdriver, const void *data,
void **handle)
{
struct romfs_mountpt_s *rm;
int ret;
/* Open the block driver */
if (!blkdriver || !blkdriver->u.i_bops)
{
return -ENODEV;
}
if (blkdriver->u.i_bops->open &&
blkdriver->u.i_bops->open(blkdriver) != OK)
{
return -ENODEV;
}
/* Create an instance of the mountpt state structure */
rm = (struct romfs_mountpt_s *)zalloc(sizeof(struct romfs_mountpt_s));
if (!rm)
{
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(&rm->rm_sem, 0, 0); /* Initialize the semaphore that controls access */
rm->rm_blkdriver = blkdriver; /* Save the block driver reference */
/* Get the hardware configuration and setup buffering appropriately */
ret = romfs_hwconfigure(rm);
if (ret < 0)
{
goto errout_with_sem;
}
/* Then complete the mount by getting the ROMFS configuratrion from
* the ROMF header
*/
ret = romfs_fsconfigure(rm);
if (ret < 0)
{
goto errout_with_buffer;
}
/* Mounted! */
*handle = (void*)rm;
romfs_semgive(rm);
return OK;
errout_with_buffer:
if (!rm->rm_xipbase)
{
free(rm->rm_buffer);
}
errout_with_sem:
sem_destroy(&rm->rm_sem);
free(rm);
return ret;
}
/****************************************************************************
* Name: romfs_unbind
*
* Description: This implements the filesystem portion of the umount
* operation.
*
****************************************************************************/
static int romfs_unbind(void *handle, FAR struct inode **blkdriver)
{
struct romfs_mountpt_s *rm = (struct romfs_mountpt_s*)handle;
int ret;
if (!rm)
{
return -EINVAL;
}
/* Check if there are sill any files opened on the filesystem. */
ret = OK; /* Assume success */
romfs_semtake(rm);
if (rm->rm_head)
{
/* We cannot unmount now.. there are open files */
ret = -EBUSY;
}
else
{
/* Unmount ... close the block driver */
if (rm->rm_blkdriver)
{
struct inode *inode = rm->rm_blkdriver;
if (inode)
{
if (inode->u.i_bops && inode->u.i_bops->close)
{
(void)inode->u.i_bops->close(inode);
}
/* We hold a reference to the block driver but should
* not but mucking with inodes in this context. So, we will just return
* our contained reference to the block driver inode and let the umount
* logic dispose of it.
*/
if (blkdriver)
{
*blkdriver = inode;
}
}
}
/* Release the mountpoint private data */
if (!rm->rm_xipbase && rm->rm_buffer)
{
free(rm->rm_buffer);
}
sem_destroy(&rm->rm_sem);
free(rm);
}
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_statfs
*
* Description: Return filesystem statistics
*
****************************************************************************/
static int romfs_statfs(struct inode *mountpt, struct statfs *buf)
{
struct romfs_mountpt_s *rm;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
rm = mountpt->i_private;
/* Check if the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret < 0)
{
goto errout_with_semaphore;
}
/* Fill in the statfs info */
memset(buf, 0, sizeof(struct statfs));
buf->f_type = ROMFS_MAGIC;
/* We will claim that the optimal transfer size is the size of one sector */
buf->f_bsize = rm->rm_hwsectorsize;
/* Everything else follows in units of sectors */
buf->f_blocks = SEC_NSECTORS(rm, rm->rm_volsize + SEC_NDXMASK(rm));
buf->f_bfree = 0;
buf->f_bavail = 0;
buf->f_namelen = NAME_MAX;
romfs_semgive(rm);
return OK;
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Name: romfs_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int romfs_stat(struct inode *mountpt, const char *relpath, struct stat *buf)
{
struct romfs_mountpt_s *rm;
struct romfs_dirinfo_s dirinfo;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
rm = mountpt->i_private;
/* Check if the mount is still healthy */
romfs_semtake(rm);
ret = romfs_checkmount(rm);
if (ret != OK)
{
goto errout_with_semaphore;
}
/* Find the directory entry corresponding to relpath. */
ret = romfs_finddirentry(rm, &dirinfo, relpath);
/* If nothing was found, then we fail with EEXIST */
if (ret < 0)
{
goto errout_with_semaphore;
}
memset(buf, 0, sizeof(struct stat));
if (IS_DIRECTORY(dirinfo.rd_next))
{
/* It's a read-only directory name */
buf->st_mode = S_IFDIR|S_IROTH|S_IRGRP|S_IRUSR;
if (IS_EXECUTABLE(dirinfo.rd_next))
{
buf->st_mode |= S_IXOTH|S_IXGRP|S_IXUSR;
}
}
else if (IS_FILE(dirinfo.rd_next))
{
/* It's a read-only file name */
buf->st_mode = S_IFREG|S_IROTH|S_IRGRP|S_IRUSR;
if (IS_EXECUTABLE(dirinfo.rd_next))
{
buf->st_mode |= S_IXOTH|S_IXGRP|S_IXUSR;
}
}
else
{
/* Otherwise, pretend like the unsupported node does not exist */
ret = -ENOENT;
goto errout_with_semaphore;
}
/* File/directory size, access block size */
buf->st_size = dirinfo.rd_size;
buf->st_blksize = rm->rm_hwsectorsize;
buf->st_blocks = (buf->st_size + buf->st_blksize - 1) / buf->st_blksize;
ret = OK;
errout_with_semaphore:
romfs_semgive(rm);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
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