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nuttx/fs/fat/fs_fat32.c
Windrow14 479c393291 fs/fat/fs_fat32.[c|h]: fix fseek bug when file size is multiple of cluster size 
Unbinding `ff_currentcluster` and `f_pos`:
1. Added `ff_pos` in `struct fat_file_s`.
2. Added function `fat_zero_cluster` for doing zeroing for gap
   between EOF and new position beyond EOF.
3. Added function `fat_get_sectors` for getting the sector where
   `f_pos` is located, allocting new cluster when `f_pos` is beyond
   EOF.
4. Modify function `fat_read`, and `fat_write` with above functions.
5. Remove redundant logics in `fat_seek` since now new cluster is
   allocated when writing instead of seeking.

Signed-off-by: Yinzhe Wu <Yinzhe.Wu@sony.com>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Jacky Cao <Jacky.Cao@sony.com>
Tested-by: Yinzhe Wu <Yinzhe.Wu@sony.com>
2024-07-06 19:00:01 +08:00

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/****************************************************************************
* fs/fat/fs_fat32.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 <sys/statfs.h>
#include <sys/mount.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/fat.h>
#include "inode/inode.h"
#include "fs_fat32.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#if defined(CONFIG_FS_LARGEFILE)
# define OFF_MAX INT64_MAX
#else
# define OFF_MAX INT32_MAX
#endif
#define ROUND_DOWN(a, b) ((a) & ~((b) - 1))
#define ROUND_UP(a, b) (((a) + (b) - 1) & ~((b) - 1))
#define DIV_ROUND_UP(a, b) (ROUND_UP(a, b) / (b))
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int fat_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int fat_close(FAR struct file *filep);
static ssize_t fat_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t fat_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static off_t fat_seek(FAR struct file *filep, off_t offset, int whence);
static int fat_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
static int fat_sync(FAR struct file *filep);
static int fat_dup(FAR const struct file *oldp, FAR struct file *newp);
static int fat_fstat(FAR const struct file *filep,
FAR struct stat *buf);
static int fat_truncate(FAR struct file *filep, off_t length);
static int fat_opendir(FAR struct inode *mountpt,
FAR const char *relpath, FAR struct fs_dirent_s **dir);
static int fat_closedir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
static int fat_readdir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir,
FAR struct dirent *entry);
static int fat_rewinddir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
static int fat_bind(FAR struct inode *blkdriver, FAR const void *data,
FAR void **handle);
static int fat_unbind(FAR void *handle,
FAR struct inode **blkdriver, unsigned int flags);
static int fat_statfs(FAR struct inode *mountpt,
FAR struct statfs *buf);
static int fat_unlink(FAR struct inode *mountpt,
FAR const char *relpath);
static int fat_mkdir(FAR struct inode *mountpt, FAR const char *relpath,
mode_t mode);
static int fat_rmdir(FAR struct inode *mountpt, FAR const char *relpath);
static int fat_rename(FAR struct inode *mountpt,
FAR const char *oldrelpath, FAR const char *newrelpath);
static int fat_stat_common(FAR struct fat_mountpt_s *fs,
FAR uint8_t *direntry, FAR struct stat *buf);
static int fat_stat_file(FAR struct fat_mountpt_s *fs,
FAR uint8_t *direntry, FAR struct stat *buf);
static int fat_stat_root(FAR struct fat_mountpt_s *fs,
FAR struct stat *buf);
static int fat_stat(struct inode *mountpt, const char *relpath,
FAR struct stat *buf);
/****************************************************************************
* Public Data
****************************************************************************/
/* See fs_mount.c -- this structure is explicitly extern'ed there.
* We use the old-fashioned kind of initializers so that this will compile
* with any compiler.
*/
const struct mountpt_operations g_fat_operations =
{
fat_open, /* open */
fat_close, /* close */
fat_read, /* read */
fat_write, /* write */
fat_seek, /* seek */
fat_ioctl, /* ioctl */
NULL, /* mmap */
fat_truncate, /* truncate */
NULL, /* poll */
fat_sync, /* sync */
fat_dup, /* dup */
fat_fstat, /* fstat */
NULL, /* fchstat */
fat_opendir, /* opendir */
fat_closedir, /* closedir */
fat_readdir, /* readdir */
fat_rewinddir, /* rewinddir */
fat_bind, /* bind */
fat_unbind, /* unbind */
fat_statfs, /* statfs */
fat_unlink, /* unlink */
fat_mkdir, /* mkdir */
fat_rmdir, /* rmdir */
fat_rename, /* rename */
fat_stat, /* stat */
NULL /* chstat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: fat_open
****************************************************************************/
static int fat_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
struct fat_dirinfo_s dirinfo;
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
uint8_t *direntry;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv == NULL);
/* Get the mountpoint inode reference from the file structure and the
* mountpoint private data from the inode structure
*/
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Initialize the directory info structure */
memset(&dirinfo, 0, sizeof(struct fat_dirinfo_s));
/* Locate the directory entry for this path */
ret = fat_finddirentry(fs, &dirinfo, relpath);
/* Three possibilities: (1) a node exists for the relpath and
* dirinfo describes the directory entry of the entity, (2) the
* node does not exist, or (3) some error occurred.
*/
if (ret == OK)
{
bool readonly;
/* The name exists -- but is it a file or a directory? */
if (dirinfo.fd_root)
{
/* It is the root directory */
ret = -EISDIR;
goto errout_with_lock;
}
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
if ((DIR_GETATTRIBUTES(direntry) & FATATTR_DIRECTORY) != 0)
{
/* It is a regular directory */
ret = -EISDIR;
goto errout_with_lock;
}
/* It would be an error if we are asked to create it exclusively */
if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
{
/* Already exists -- can't create it exclusively */
ret = -EEXIST;
goto errout_with_lock;
}
/* Check if the caller has sufficient privileges to open the file */
readonly = ((DIR_GETATTRIBUTES(direntry) & FATATTR_READONLY) != 0);
if (((oflags & O_WRONLY) != 0) && readonly)
{
ret = -EACCES;
goto errout_with_lock;
}
/* If O_TRUNC is specified and the file is opened for writing,
* then truncate the file. This operation requires that the file is
* writeable, but we have already checked that. O_TRUNC without write
* access is ignored.
*/
if ((oflags & (O_TRUNC | O_WRONLY)) == (O_TRUNC | O_WRONLY))
{
/* Truncate the file to zero length */
ret = fat_dirtruncate(fs, direntry);
if (ret < 0)
{
goto errout_with_lock;
}
}
/* fall through to finish the file open operations */
}
/* ENOENT would be returned by fat_finddirentry() if the full directory
* path was found, but the file was not found in the final directory.
*/
else if (ret == -ENOENT)
{
/* The file does not exist. Were we asked to create it? */
if ((oflags & O_CREAT) == 0)
{
/* No.. then we fail with -ENOENT */
ret = -ENOENT;
goto errout_with_lock;
}
/* Yes.. create the file */
ret = fat_dircreate(fs, &dirinfo);
if (ret < 0)
{
goto errout_with_lock;
}
/* Fall through to finish the file open operation */
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
}
/* No other error is handled */
else
{
/* An error occurred while checking for file existence --
* such as if an invalid path were provided.
*/
goto errout_with_lock;
}
/* Create an instance of the file private date to describe the opened
* file.
*/
ff = kmm_zalloc(sizeof(struct fat_file_s));
if (!ff)
{
ret = -ENOMEM;
goto errout_with_lock;
}
/* Create a file buffer to support partial sector accesses */
ff->ff_buffer = (FAR uint8_t *)fat_io_alloc(fs->fs_hwsectorsize);
if (!ff->ff_buffer)
{
ret = -ENOMEM;
goto errout_with_struct;
}
/* Initialize the file private data (only need to initialize non-zero
* elements).
*/
ff->ff_oflags = oflags;
/* Save information that can be used later to recover the directory entry */
ff->ff_dirsector = fs->fs_currentsector;
ff->ff_dirindex = dirinfo.dir.fd_index;
/* File cluster/size info */
ff->ff_startcluster =
((uint32_t)DIR_GETFSTCLUSTHI(direntry) << 16) |
DIR_GETFSTCLUSTLO(direntry);
ff->ff_currentcluster = ff->ff_startcluster;
ff->ff_sectorsincluster = fs->fs_fatsecperclus;
ff->ff_size = DIR_GETFILESIZE(direntry);
/* Attach the private date to the struct file instance */
filep->f_priv = ff;
/* 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).
*/
ff->ff_next = fs->fs_head;
fs->fs_head = ff;
nxmutex_unlock(&fs->fs_lock);
/* In write/append mode, we need to set the file pointer to the end of
* the file.
*/
if ((oflags & (O_APPEND | O_WRONLY)) == (O_APPEND | O_WRONLY))
{
off_t offset = fat_seek(filep, ff->ff_size, SEEK_SET);
if (offset < 0)
{
kmm_free(ff);
return (int)offset;
}
}
return OK;
/* Error exits -- goto's are nasty things, but they sure can make error
* handling a lot simpler.
*/
errout_with_struct:
kmm_free(ff);
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_close
****************************************************************************/
static int fat_close(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct fat_file_s *ff;
FAR struct fat_file_s *currff;
FAR struct fat_file_s *prevff;
FAR struct fat_mountpt_s *fs;
int ret = OK;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Check for the forced mount condition */
if ((ff->ff_bflags & UMOUNT_FORCED) == 0)
{
/* Do not check if the mount is healthy. We must support closing of
* the file even when there is healthy mount.
*/
/* Synchronize the file buffers and disk content; update times */
ret = fat_sync(filep);
/* Remove the file structure from the list of open files in the
* mountpoint structure.
*/
for (prevff = NULL, currff = fs->fs_head;
currff && currff != ff;
prevff = currff, currff = currff->ff_next);
if (currff)
{
if (prevff)
{
prevff->ff_next = ff->ff_next;
}
else
{
fs->fs_head = ff->ff_next;
}
}
}
/* Then deallocate the memory structures created when the open method
* was called.
*
* Free the sector buffer that was used to manage partial sector accesses.
*/
if (ff->ff_buffer)
{
fat_io_free(ff->ff_buffer, fs->fs_hwsectorsize);
}
/* Then free the file structure itself. */
kmm_free(ff);
filep->f_priv = NULL;
return ret;
}
/****************************************************************************
* Name: fat_zero_cluster
* Description:
* Zero the data in a cluster. Use to zero the data in the gap between EOF
* and the write offset.
*
* Input Parameters:
* fs - A reference to the fat volume object instance
* cluster - Cluster index to be zeroed
* start - The starting position in the cluster
* end - The ending position in the cluster
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure.
*
****************************************************************************/
static int fat_zero_cluster(FAR struct fat_mountpt_s *fs, int cluster,
int start, int end)
{
FAR uint8_t *buf;
int zero_len = fs->fs_hwsectorsize - (start & (fs->fs_hwsectorsize - 1));
off_t i;
off_t sector = fat_cluster2sector(fs, cluster);
off_t start_sec = sector + start / fs->fs_hwsectorsize;
off_t end_sec = sector + DIV_ROUND_UP(end, fs->fs_hwsectorsize);
int ret;
buf = kmm_malloc(fs->fs_hwsectorsize);
if (!buf)
{
return -ENOMEM;
}
if (zero_len)
{
ret = fat_hwread(fs, buf, start_sec, 1);
if (ret < 0)
{
goto out;
}
memset(buf + fs->fs_hwsectorsize - zero_len, 0, zero_len);
ret = fat_hwwrite(fs, buf, start_sec, 1);
if (ret < 0)
{
goto out;
}
start_sec++;
}
memset(buf, 0, fs->fs_hwsectorsize - zero_len);
for (i = start_sec; i < end_sec; i++)
{
ret = fat_hwwrite(fs, buf, i, 1);
if (ret < 0)
{
goto out;
}
}
ret = OK;
out:
kmm_free(buf);
return ret;
}
/****************************************************************************
* Name: fat_get_sectors
*
* Description:
* Get the sector index where ->f_pos is located. This function will
* allocate new clusters if get sectors for writing and ->f_pos is out of
* EOF and zero the data in the gap between EOF and the write offset.
*
* Input Parameters:
* fs - A reference to the file
* read - True if get sectors for reading
*
* Output:
* ->ff_currentsector - the sector index where ->f_pos is located
* ->ff_currentcluster - the cluster index where ->f_pos is located
* ->ff_sectorsincluster - sectors remaining in cluster
* ->ff_startcluster - the first cluster of the file when writing an
* empty file
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure.
*
****************************************************************************/
static int fat_get_sectors(FAR struct file *filep, bool read)
{
FAR struct inode *inode = filep->f_inode;
FAR struct fat_mountpt_s *fs = inode->i_private;
FAR struct fat_file_s *ff = filep->f_priv;
int i;
int num_clu;
int new_num_clu;
int num_traversed;
int cluster;
int ret;
int zero_start;
int zero_end;
int clu_size = fs->fs_fatsecperclus * fs->fs_hwsectorsize;
num_clu = DIV_ROUND_UP(ff->ff_size, clu_size);
new_num_clu = DIV_ROUND_UP(filep->f_pos + 1, clu_size);
if (ff->ff_startcluster == 0)
{
/* empty file */
cluster = 0;
num_traversed = 0;
}
else if (ff->ff_currentcluster >= 2 &&
ff->ff_currentcluster < fs->fs_nclusters + 2 &&
ff->ff_pos <= filep->f_pos)
{
/* fatchain is traversed but not reach filep->f_pos */
cluster = ff->ff_currentcluster;
num_traversed = ff->ff_pos / clu_size + 1;
}
else
{
/* Traverse the FATchain from the first cluster of the file */
cluster = ff->ff_startcluster;
num_traversed = 1;
}
/* Traverse the existing chain */
for (i = num_traversed; i < num_clu && i < new_num_clu; i++)
{
cluster = fat_getcluster(fs, cluster);
/* The chain is broken */
if (cluster < 2 || cluster >= fs->fs_nclusters + 2)
{
return -EIO;
}
}
if (read)
{
goto out;
}
/* The 3 areas should be zeroed.
*
* cluster cluster+1..N cluster+2..N+1
* +-------------------+------------------+---------------------+
* | | (1) | (2) | (3) | | |
* +-------------------+------------------+---------------------+
* ^ ^
* ff_size f_pos
*/
/* zero area (1) */
if (i == num_clu && filep->f_pos > ff->ff_size && ff->ff_size)
{
zero_start = ff->ff_size & (clu_size - 1);
if (num_clu == new_num_clu)
{
zero_end = filep->f_pos & (clu_size - 1);
}
else
{
zero_end = clu_size;
}
fat_ffcacheinvalidate(fs, ff);
ret = fat_zero_cluster(fs, cluster, zero_start, zero_end);
if (ret)
{
return ret;
}
}
/* Append new clusters for writing */
for (; i < new_num_clu - 1; i++)
{
cluster = fat_extendchain(fs, cluster);
if (cluster < 2 || cluster >= fs->fs_nclusters + 2)
{
return -EIO;
}
/* zero area (2) */
ret = fat_zero_cluster(fs, cluster, 0, clu_size);
if (ret < 0)
{
return ret;
}
if (ff->ff_startcluster == 0)
{
ff->ff_startcluster = cluster;
}
}
if (i == new_num_clu - 1)
{
cluster = fat_extendchain(fs, cluster);
if (cluster < 2 || cluster >= fs->fs_nclusters + 2)
{
return -EIO;
}
/* zero area (3) */
zero_end = filep->f_pos & (clu_size -1);
if (zero_end)
{
ret = fat_zero_cluster(fs, cluster, 0, zero_end);
if (ret < 0)
{
return ret;
}
}
if (ff->ff_startcluster == 0)
{
ff->ff_startcluster = cluster;
}
}
if (filep->f_pos > ff->ff_size)
{
ff->ff_size = filep->f_pos;
}
out:
ff->ff_currentcluster = cluster;
ret = fat_currentsector(fs, ff, filep->f_pos);
if (ret < 0)
{
return ret;
}
ff->ff_pos = ROUND_DOWN(filep->f_pos, clu_size);
return 0;
}
/****************************************************************************
* Name: fat_read
****************************************************************************/
static ssize_t fat_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
unsigned int bytesread;
unsigned int readsize;
size_t bytesleft;
FAR uint8_t *userbuffer = (FAR uint8_t *)buffer;
int sectorindex;
int ret;
#ifndef CONFIG_FAT_FORCE_INDIRECT
unsigned int nsectors;
bool force_indirect = false;
#endif
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
/* Check for the forced mount condition */
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if the file was opened with read access */
if ((ff->ff_oflags & O_RDOK) == 0)
{
ret = -EACCES;
goto errout_with_lock;
}
/* Check that the file position is not past the end of the file */
if (filep->f_pos > ff->ff_size)
{
/* Return EOF */
ret = 0;
goto errout_with_lock;
}
else
{
/* Get the number of bytes left in the file */
bytesleft = ff->ff_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. We assume we start with the current sector (ff_currentsector)
* which may be uninitialized.
*/
readsize = 0;
sectorindex = filep->f_pos & SEC_NDXMASK(fs);
while (buflen > 0)
{
bytesread = 0;
ret = fat_get_sectors(filep, true);
if (ret < 0)
{
goto errout_with_lock;
}
#ifdef CONFIG_FAT_DIRECT_RETRY /* Warning avoidance */
fat_read_restart:
#endif
#ifndef CONFIG_FAT_FORCE_INDIRECT
/* 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 = buflen / fs->fs_hwsectorsize;
if (nsectors > 0 && sectorindex == 0 && !force_indirect)
{
/* Read maximum contiguous sectors directly to the user's
* buffer without using our tiny read buffer.
*
* Limit the number of sectors that we read on this time
* through the loop to the remaining contiguous sectors
* in this cluster
*/
if (nsectors > ff->ff_sectorsincluster)
{
nsectors = ff->ff_sectorsincluster;
}
/* We are not sure of the state of the file buffer so
* the safest thing to do is just invalidate it
*/
fat_ffcacheinvalidate(fs, ff);
/* Read all of the sectors directly into user memory */
ret = fat_hwread(fs, userbuffer, ff->ff_currentsector, nsectors);
if (ret < 0)
{
#ifdef CONFIG_FAT_DIRECT_RETRY
/* The low-level driver may return -EFAULT in the case where
* the transfer cannot be performed due to buffer memory
* constraints. It is probable that the buffer is completely
* un-DMA-able or improperly aligned. In this case, force
* indirect transfers via the sector buffer and restart the
* operation (unless we have already tried that).
*/
if (ret == -EFAULT && !force_indirect)
{
ferr("ERROR: DMA read alignment error,"
" restarting indirect\n");
force_indirect = true;
goto fat_read_restart;
}
#endif /* CONFIG_FAT_DIRECT_RETRY */
goto errout_with_lock;
}
ff->ff_sectorsincluster -= nsectors;
ff->ff_currentsector += nsectors;
bytesread = nsectors * fs->fs_hwsectorsize;
}
else
#endif /* CONFIG_FAT_FORCE_INDIRECT */
{
/* We are reading a partial sector, or handling a non-DMA-able
* whole-sector transfer. 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 = fat_ffcacheread(fs, ff, ff->ff_currentsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Copy the requested part of the sector into the user buffer */
bytesread = fs->fs_hwsectorsize - sectorindex;
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) */
ff->ff_sectorsincluster--;
ff->ff_currentsector++;
}
memcpy(userbuffer, &ff->ff_buffer[sectorindex], bytesread);
}
/* Set up for the next sector read */
userbuffer += bytesread;
filep->f_pos += bytesread;
readsize += bytesread;
buflen -= bytesread;
sectorindex = filep->f_pos & SEC_NDXMASK(fs);
}
nxmutex_unlock(&fs->fs_lock);
return readsize;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_write
****************************************************************************/
static ssize_t fat_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
unsigned int byteswritten;
unsigned int writesize;
FAR uint8_t *userbuffer = (FAR uint8_t *)buffer;
int sectorindex;
int ret;
#ifndef CONFIG_FAT_FORCE_INDIRECT
unsigned int nsectors;
bool force_indirect = false;
#endif
DEBUGASSERT(filep->f_priv != NULL);
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
/* Check for the forced mount condition */
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if the file was opened for write access */
if ((ff->ff_oflags & O_WROK) == 0)
{
ret = -EACCES;
goto errout_with_lock;
}
/* Check if the file size would exceed the range of off_t */
if (buflen > OFF_MAX || ff->ff_size > OFF_MAX - (off_t)buflen)
{
ret = -EFBIG;
goto errout_with_lock;
}
/* Loop until either (1) all data has been transferred, or (2) an
* error occurs. We assume we start with the current sector in
* cache (ff_currentsector)
*/
byteswritten = 0;
sectorindex = filep->f_pos & SEC_NDXMASK(fs);
while (buflen > 0)
{
ret = fat_get_sectors(filep, false);
if (ret < 0)
{
goto errout_with_lock;
}
#ifdef CONFIG_FAT_DIRECT_RETRY /* Warning avoidance */
fat_write_restart:
#endif
#ifndef CONFIG_FAT_FORCE_INDIRECT
/* Check if the user has provided a buffer large enough to
* hold one or more complete sectors.
*/
nsectors = buflen / fs->fs_hwsectorsize;
if (nsectors > 0 && sectorindex == 0 && !force_indirect)
{
/* Write maximum contiguous sectors directly from the user's
* buffer without using our tiny read buffer.
*
* Limit the number of sectors that we write on this time
* through the loop to the remaining contiguous sectors
* in this cluster
*/
if (nsectors > ff->ff_sectorsincluster)
{
nsectors = ff->ff_sectorsincluster;
}
/* We are not sure of the state of the sector cache so the
* safest thing to do is write back any dirty, cached sector
* and invalidate the current cache content.
*/
fat_ffcacheinvalidate(fs, ff);
/* Write all of the sectors directly from user memory */
ret = fat_hwwrite(fs, userbuffer, ff->ff_currentsector, nsectors);
if (ret < 0)
{
#ifdef CONFIG_FAT_DIRECT_RETRY
/* The low-level driver may return -EFAULT in the case where
* the transfer cannot be performed due to buffer memory
* constraints. It is probable that the buffer is completely
* un-DMA-able or improperly aligned. In this case, force
* indirect transfers via the sector buffer and restart the
* operation (unless we have already tried that).
*/
if (ret == -EFAULT && !force_indirect)
{
ferr("ERROR: DMA write alignment error,"
" restarting indirect\n");
force_indirect = true;
goto fat_write_restart;
}
#endif /* CONFIG_FAT_DIRECT_RETRY */
goto errout_with_lock;
}
ff->ff_sectorsincluster -= nsectors;
ff->ff_currentsector += nsectors;
writesize = nsectors * fs->fs_hwsectorsize;
ff->ff_bflags |= FFBUFF_MODIFIED;
}
else
#endif /* CONFIG_FAT_FORCE_INDIRECT */
{
/* Decide whether we are performing a read-modify-write
* operation, in which case we have to read the existing sector
* into the buffer first.
*
* There are two cases where we can avoid this read:
*
* - If we are performing a whole-sector write that was rejected
* by fat_hwwrite(), i.e. sectorindex == 0 and buflen >= sector
* size.
*
* - If the write is aligned to the beginning of the sector and
* extends beyond the end of the file, i.e. sectorindex == 0 and
* file pos + buflen >= file size.
*/
if ((sectorindex == 0) && ((buflen >= fs->fs_hwsectorsize) ||
((filep->f_pos + buflen) >= ff->ff_size)))
{
/* Flush unwritten data in the sector cache. */
ret = fat_ffcacheflush(fs, ff);
if (ret < 0)
{
goto errout_with_lock;
}
/* Now mark the clean cache buffer as the current sector. */
ff->ff_cachesector = ff->ff_currentsector;
}
else
{
/* Read the current sector into memory (perhaps first flushing
* the old, dirty sector to disk).
*/
ret = fat_ffcacheread(fs, ff, ff->ff_currentsector);
if (ret < 0)
{
goto errout_with_lock;
}
}
/* Copy the requested part of the sector from the user buffer */
writesize = fs->fs_hwsectorsize - sectorindex;
if (writesize > buflen)
{
/* We will not write to the end of the buffer. Set
* write size to the size of the user buffer.
*/
writesize = buflen;
}
else
{
/* We will write to the end of the buffer (or beyond). Bump
* up the current sector number (actually the next sector
* number).
*/
ff->ff_sectorsincluster--;
ff->ff_currentsector++;
}
/* Copy the data into the cached sector and make sure that the
* cached sector is marked "dirty"
*/
memcpy(&ff->ff_buffer[sectorindex], userbuffer, writesize);
ff->ff_bflags |= (FFBUFF_DIRTY | FFBUFF_VALID | FFBUFF_MODIFIED);
}
/* Set up for the next write */
userbuffer += writesize;
filep->f_pos += writesize;
byteswritten += writesize;
buflen -= writesize;
sectorindex = filep->f_pos & SEC_NDXMASK(fs);
/* Update the file size */
if (filep->f_pos > ff->ff_size)
{
ff->ff_size = filep->f_pos;
}
}
nxmutex_unlock(&fs->fs_lock);
return byteswritten;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_seek
****************************************************************************/
static off_t fat_seek(FAR struct file *filep, off_t offset, int whence)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
off_t position;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
/* Check for the forced mount condition */
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != 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 + ff->ff_size;
break;
default:
return -EINVAL;
}
/* Invalid arguments are entered, returns an error. */
if (position < 0)
{
return -EINVAL;
}
/* Special case: We are seeking to the current position. This would
* happen normally with ftell() which does lseek(fd, 0, SEEK_CUR) but can
* also happen in other situation such as when SEEK_SET is used to assure
* assure sequential access in a multi-threaded environment where there
* may be are multiple users to the file descriptor.
* Effectively handles the situation when a new file position is within
* the current sector.
*/
if (position / fs->fs_hwsectorsize == filep->f_pos / fs->fs_hwsectorsize)
{
filep->f_pos = position;
return OK;
}
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if there is unwritten data in the file buffer */
ret = fat_ffcacheflush(fs, ff);
if (ret < 0)
{
goto errout_with_lock;
}
filep->f_pos = position;
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_ioctl
****************************************************************************/
static int fat_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct fat_file_s *ff;
FAR struct fat_mountpt_s *fs;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Check for the forced mount condition */
ff = filep->f_priv;
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
/* Recover our private data from the struct file instance */
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/* ioctl calls are just passed through to the contained block driver */
nxmutex_unlock(&fs->fs_lock);
return -ENOTTY;
}
/****************************************************************************
* Name: fat_sync
*
* Description: Synchronize the file state on disk to match internal, in-
* memory state.
*
****************************************************************************/
static int fat_sync(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
uint32_t wrttime;
uint8_t *direntry;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Check for the forced mount condition */
ff = filep->f_priv;
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
/* Recover our private data from the struct file instance */
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if the has been modified in any way */
if ((ff->ff_bflags & FFBUFF_MODIFIED) != 0)
{
uint8_t dircopy[DIR_SIZE];
/* Flush any unwritten data in the file buffer */
ret = fat_ffcacheflush(fs, ff);
if (ret < 0)
{
goto errout_with_lock;
}
/* Update the directory entry. First read the directory
* entry into the fs_buffer (preserving the ff_buffer)
*/
ret = fat_fscacheread(fs, ff->ff_dirsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Recover a pointer to the specific directory entry
* in the sector using the saved directory index.
*/
direntry = &fs->fs_buffer[(ff->ff_dirindex & DIRSEC_NDXMASK(fs)) *
DIR_SIZE];
/* Copy directory entry */
memcpy(dircopy, direntry, DIR_SIZE);
/* Set the archive bit, set the write time, and update
* anything that may have* changed in the directory
* entry: the file size, and the start cluster
*/
direntry[DIR_ATTRIBUTES] |= FATATTR_ARCHIVE;
DIR_PUTFILESIZE(direntry, ff->ff_size);
DIR_PUTFSTCLUSTLO(direntry, ff->ff_startcluster);
DIR_PUTFSTCLUSTHI(direntry, ff->ff_startcluster >> 16);
wrttime = fat_systime2fattime();
DIR_PUTWRTTIME(direntry, wrttime & 0xffff);
DIR_PUTWRTDATE(direntry, wrttime >> 16);
/* Clear the modified bit in the flags */
ff->ff_bflags &= ~FFBUFF_MODIFIED;
/* Compare old and new directory entry */
if (memcmp(direntry, dircopy, DIR_SIZE) != 0)
{
fs->fs_dirty = true;
}
/* Flush these change to disk and update FSINFO (if
* appropriate.
*/
ret = fat_updatefsinfo(fs);
}
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_dup
*
* Description: Duplicate open file data in the new file structure.
*
****************************************************************************/
static int fat_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *oldff;
FAR struct fat_file_s *newff;
int ret;
finfo("Dup %p->%p\n", oldp, newp);
/* Sanity checks */
DEBUGASSERT(oldp->f_priv != NULL &&
newp->f_priv == NULL &&
newp->f_inode != NULL);
/* Recover the old private data from the old struct file instance */
oldff = oldp->f_priv;
/* Check for the forced mount condition */
if ((oldff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
/* Recover our private data from the struct file instance */
fs = oldp->f_inode->i_private;
DEBUGASSERT(fs != NULL);
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Create a new instance of the file private date to describe the
* dup'ed file.
*/
newff = kmm_malloc(sizeof(struct fat_file_s));
if (!newff)
{
ret = -ENOMEM;
goto errout_with_lock;
}
/* Create a file buffer to support partial sector accesses */
newff->ff_buffer = (FAR uint8_t *)fat_io_alloc(fs->fs_hwsectorsize);
if (!newff->ff_buffer)
{
ret = -ENOMEM;
goto errout_with_struct;
}
/* Copy the rest of the open open file state from the old file structure.
* There are some assumptions and potential issues here:
*
* 1) We assume that the higher level logic has copied the elements of
* the file structure, in particular, the file position.
* 2) There is a problem with ff_size if there are multiple opened
* file structures, each believing they know the size of the file.
* If one instance modifies the file length, then the new size of
* the opened file will be unknown to the other. That is a lurking
* bug!
*
* One good solution to this might be to add a reference count to the
* file structure. Then, instead of dup'ing the whole structure
* as is done here, just increment the reference count on the
* structure. The would have to be integrated with open logic as
* well, however, so that the same file structure is re-used if the
* file is re-opened.
*/
newff->ff_bflags = 0; /* File buffer flags */
newff->ff_oflags = oldff->ff_oflags; /* File open flags */
newff->ff_sectorsincluster = oldff->ff_sectorsincluster; /* Sectors remaining in cluster */
newff->ff_dirindex = oldff->ff_dirindex; /* Index to directory entry */
newff->ff_currentcluster = oldff->ff_currentcluster; /* Current cluster */
newff->ff_dirsector = oldff->ff_dirsector; /* Sector containing directory entry */
newff->ff_size = oldff->ff_size; /* Size of the file */
newff->ff_startcluster = oldff->ff_startcluster; /* Start cluster of file on media */
newff->ff_currentsector = oldff->ff_currentsector; /* Current sector */
newff->ff_cachesector = 0; /* Sector in file buffer */
/* Attach the private date to the struct file instance */
newp->f_priv = newff;
/* 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).
*/
newff->ff_next = fs->fs_head;
fs->fs_head = newff;
nxmutex_unlock(&fs->fs_lock);
return OK;
/* Error exits -- goto's are nasty things, but they sure can make error
* handling a lot simpler.
*/
errout_with_struct:
kmm_free(newff);
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_opendir
*
* Description: Open a directory for read access
*
****************************************************************************/
static int fat_opendir(FAR struct inode *mountpt, FAR const char *relpath,
FAR struct fs_dirent_s **dir)
{
FAR struct fat_dirent_s *fdir;
FAR struct fat_mountpt_s *fs;
FAR struct fat_dirinfo_s dirinfo;
uint8_t *direntry;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
fs = mountpt->i_private;
fdir = kmm_zalloc(sizeof(struct fat_dirent_s));
if (fdir == NULL)
{
return -ENOMEM;
}
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
goto errout_with_fdir;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Find the requested directory */
ret = fat_finddirentry(fs, &dirinfo, relpath);
if (ret < 0)
{
goto errout_with_lock;
}
/* Check if this is the root directory */
if (dirinfo.fd_root)
{
/* Handle the FAT12/16/32 root directory using the values setup by
* fat_finddirentry() above.
*/
fdir->dir.fd_startcluster = dirinfo.dir.fd_startcluster;
fdir->dir.fd_currcluster = dirinfo.dir.fd_currcluster;
fdir->dir.fd_currsector = dirinfo.dir.fd_currsector;
fdir->dir.fd_index = dirinfo.dir.fd_index;
}
else
{
/* This is not the root directory. Verify that it is some kind of
* directory.
*/
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
if ((DIR_GETATTRIBUTES(direntry) & FATATTR_DIRECTORY) == 0)
{
/* The entry is not a directory */
ret = -ENOTDIR;
goto errout_with_lock;
}
else
{
/* The entry is a directory (but not the root directory) */
fdir->dir.fd_startcluster =
((uint32_t)DIR_GETFSTCLUSTHI(direntry) << 16) |
DIR_GETFSTCLUSTLO(direntry);
fdir->dir.fd_currcluster = fdir->dir.fd_startcluster;
fdir->dir.fd_currsector = fat_cluster2sector(fs,
fdir->dir.fd_currcluster);
fdir->dir.fd_index = 2;
}
}
*dir = (FAR struct fs_dirent_s *)fdir;
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
errout_with_fdir:
kmm_free(fdir);
return ret;
}
/****************************************************************************
* Name: fat_closedir
*
* Description: Close directory
*
****************************************************************************/
static int fat_closedir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir)
{
DEBUGASSERT(dir);
kmm_free(dir);
return 0;
}
/****************************************************************************
* Name: fat_fstat
*
* Description:
* Obtain information about an open file associated with the file
* structure 'filep', and will write it to the area pointed to by 'buf'.
*
****************************************************************************/
static int fat_fstat(FAR const struct file *filep, FAR struct stat *buf)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
uint8_t *direntry;
int ret;
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL);
/* Get the mountpoint inode reference from the file structure and the
* mountpoint private data from the inode structure
*/
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
/* Update the directory entry. First read the directory
* entry into the fs_buffer (preserving the ff_buffer)
*/
ret = fat_fscacheread(fs, ff->ff_dirsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Recover a pointer to the specific directory entry in the sector using
* the saved directory index.
*/
direntry = &fs->fs_buffer[(ff->ff_dirindex & DIRSEC_NDXMASK(fs)) *
DIR_SIZE];
/* Call fat_stat_file() to create the buf and to save information to
* it.
*/
ret = fat_stat_file(fs, direntry, buf);
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_truncate
*
* Description:
* Set the length of the open, regular file associated with the file
* structure 'filep' to 'length'.
*
****************************************************************************/
static int fat_truncate(FAR struct file *filep, off_t length)
{
FAR struct inode *inode;
FAR struct fat_mountpt_s *fs;
FAR struct fat_file_s *ff;
off_t oldsize;
int ret;
DEBUGASSERT(filep->f_priv != NULL);
/* Recover our private data from the struct file instance */
ff = filep->f_priv;
/* Check for the forced mount condition */
if ((ff->ff_bflags & UMOUNT_FORCED) != 0)
{
return -EPIPE;
}
inode = filep->f_inode;
fs = inode->i_private;
DEBUGASSERT(fs != NULL);
/* Make sure that the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if the file was opened for write access */
if ((ff->ff_oflags & O_WROK) == 0)
{
ret = -EACCES;
goto errout_with_lock;
}
/* Are we shrinking the file? Or extending it? */
oldsize = ff->ff_size;
if (oldsize == length)
{
/* Do nothing but say that we did */
ret = OK;
}
else if (oldsize > length)
{
FAR uint8_t *direntry;
int ndx;
/* We are shrinking the file.
*
* Read the directory entry into the fs_buffer.
*/
ret = fat_fscacheread(fs, ff->ff_dirsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Recover a pointer to the specific directory entry in the sector
* using the saved directory index.
*/
ndx = (ff->ff_dirindex & DIRSEC_NDXMASK(fs)) * DIR_SIZE;
direntry = &fs->fs_buffer[ndx];
/* Handle the simple case where we are shrinking the file to zero
* length.
*/
if (length == 0)
{
/* Shrink to length == 0 */
ret = fat_dirtruncate(fs, direntry);
}
else
{
/* Shrink to 0 < length < oldsize */
ret = fat_dirshrink(fs, direntry, length);
}
if (ret >= 0)
{
/* The truncation has completed without error. Update the file
* size.
*/
ff->ff_size = length;
ret = OK;
}
}
else
{
/* Otherwise we are extending the file. This is essentially the same
* as a write except that (1) we write zeros and (2) we don't update
* the file position.
*/
ret = fat_dirextend(fs, ff, length);
if (ret >= 0)
{
/* The truncation has completed without error. Update the file
* size.
*/
ff->ff_size = length;
ret = OK;
}
}
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int fat_readdir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir,
FAR struct dirent *entry)
{
FAR struct fat_dirent_s *fdir;
FAR struct fat_mountpt_s *fs;
unsigned int dirindex;
FAR uint8_t *direntry;
uint8_t ch;
uint8_t attribute;
bool found;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
fs = mountpt->i_private;
fdir = (FAR struct fat_dirent_s *)dir;
/* Make sure that the mount is still healthy.
* REVISIT: What if a forced unmount was done since opendir() was called?
*/
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Read the next directory entry */
entry->d_name[0] = '\0';
found = false;
while (fdir->dir.fd_currsector && !found)
{
ret = fat_fscacheread(fs, fdir->dir.fd_currsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Get a reference to the current directory entry */
dirindex = (fdir->dir.fd_index & DIRSEC_NDXMASK(fs)) * DIR_SIZE;
direntry = &fs->fs_buffer[dirindex];
/* Has it reached to end of the directory */
ch = *direntry;
if (ch == DIR0_ALLEMPTY)
{
/* We signal the end of the directory by returning the
* special error -ENOENT
*/
ret = -ENOENT;
goto errout_with_lock;
}
/* No, is the current entry a valid entry? */
attribute = DIR_GETATTRIBUTES(direntry);
#ifdef CONFIG_FAT_LFN
if (ch != DIR0_EMPTY &&
((attribute & FATATTR_VOLUMEID) == 0 ||
((ch & LDIR0_LAST) != 0 && attribute == LDDIR_LFNATTR)))
#else
if (ch != DIR0_EMPTY && (attribute & FATATTR_VOLUMEID) == 0)
#endif
{
/* Yes.. get the name from the directory entry. NOTE: For the case
* of the long file name entry, this will advance the several
* several directory entries.
*/
ret = fat_dirname2path(fs, dir, entry);
if (ret == OK)
{
/* The name was successfully extracted. Re-read the
* attributes: If this is long directory entry, then the
* attributes that we need will be the final, short file
* name entry and not in the directory entry where we started
* looking for the file name. We can be assured that, on
* success, fat_dirname2path() will leave the short file name
* entry in the cache regardless of the kind of directory
* entry. We simply have to re-read it to cover the long
* file name case.
*/
#ifdef CONFIG_FAT_LFN
/* Get a reference to the current, short file name directory
* entry.
*/
dirindex = (fdir->dir.fd_index & DIRSEC_NDXMASK(fs)) *
DIR_SIZE;
direntry = &fs->fs_buffer[dirindex];
/* Then re-read the attributes from the short file name entry */
attribute = DIR_GETATTRIBUTES(direntry);
#endif
/* Now get the file type from the directory attributes. */
if ((attribute & FATATTR_DIRECTORY) == 0)
{
entry->d_type = DTYPE_FILE;
}
else
{
entry->d_type = DTYPE_DIRECTORY;
}
/* Mark the entry found. We will set up the next directory
* index, and then exit with success.
*/
found = true;
}
}
/* Set up the next directory index */
if (fat_nextdirentry(fs, &fdir->dir) != OK)
{
ret = -ENOENT;
goto errout_with_lock;
}
}
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int fat_rewinddir(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir)
{
FAR struct fat_dirent_s *fdir;
FAR struct fat_mountpt_s *fs;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt != NULL && mountpt->i_private != NULL);
/* Recover our private data from the inode instance */
fs = mountpt->i_private;
fdir = (FAR struct fat_dirent_s *)dir;
/* Make sure that the mount is still healthy
* REVISIT: What if a forced unmount was done since opendir() was called?
*/
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Check if this is the root directory. If it is the root directory, we
* reset the fd_index to 0, starting with the initial, entry.
*/
if (fs->fs_type != FSTYPE_FAT32 &&
fdir->dir.fd_startcluster == 0)
{
/* Handle the FAT12/16 root directory */
fdir->dir.fd_currcluster = 0;
fdir->dir.fd_currsector = fs->fs_rootbase;
fdir->dir.fd_index = 0;
}
else if (fs->fs_type == FSTYPE_FAT32 &&
fdir->dir.fd_startcluster == fs->fs_rootbase)
{
/* Handle the FAT32 root directory */
fdir->dir.fd_currcluster = fdir->dir.fd_startcluster;
fdir->dir.fd_currsector = fat_cluster2sector(fs, fs->fs_rootbase);
fdir->dir.fd_index = 0;
}
/* This is not the root directory. Here the fd_index is set to 2, skipping
* over both the "." and ".." entries.
*/
else
{
fdir->dir.fd_currcluster = fdir->dir.fd_startcluster;
fdir->dir.fd_currsector = fat_cluster2sector(fs,
fdir->dir.fd_currcluster);
fdir->dir.fd_index = 2;
}
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ERROR;
}
/****************************************************************************
* Name: fat_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 fat_bind(FAR struct inode *blkdriver, FAR const void *data,
FAR void **handle)
{
FAR struct fat_mountpt_s *fs;
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 */
fs = kmm_zalloc(sizeof(struct fat_mountpt_s));
if (!fs)
{
return -ENOMEM;
}
/* Initialize the allocated mountpt state structure. The filesystem is
* responsible for one reference on the blkdriver inode and does not
* have to addref() here (but does have to release in unbind().
*/
fs->fs_blkdriver = blkdriver; /* Save the block driver reference */
nxmutex_init(&fs->fs_lock); /* Initialize the mutex that controls access */
/* Then get information about the FAT32 filesystem on the devices managed
* by this block driver.
*/
ret = fat_mount(fs, true);
if (ret != 0)
{
nxmutex_destroy(&fs->fs_lock);
kmm_free(fs);
return ret;
}
*handle = (FAR void *)fs;
return OK;
}
/****************************************************************************
* Name: fat_unbind
*
* Description: This implements the filesystem portion of the umount
* operation.
*
****************************************************************************/
static int fat_unbind(FAR void *handle, FAR struct inode **blkdriver,
unsigned int flags)
{
FAR struct fat_mountpt_s *fs = (FAR struct fat_mountpt_s *)handle;
int ret;
if (!fs)
{
return -EINVAL;
}
/* Check if there are sill any files opened on the filesystem. */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
if (fs->fs_head)
{
/* There are open files. We umount now unless we are forced with the
* MNT_FORCE flag. Forcing the unmount will cause data loss because
* the filesystem buffers are not flushed to the media. MNT_DETACH,
* the 'lazy' unmount, could be implemented to fix this.
*/
if ((flags & MNT_FORCE) != 0)
{
FAR struct fat_file_s *ff;
/* Set a flag in each open file structure. This flag will signal
* the file system to fail any subsequent attempts to used the
* file handle.
*/
for (ff = fs->fs_head; ff; ff = ff->ff_next)
{
ff->ff_bflags |= UMOUNT_FORCED;
}
}
else
{
/* We cannot unmount now.. there are open files. This
* implementation does not support any other umount2()
* options.
*/
nxmutex_unlock(&fs->fs_lock);
return (flags != 0) ? -ENOSYS : -EBUSY;
}
}
/* Unmount ... close the block driver */
if (fs->fs_blkdriver)
{
FAR struct inode *inode = fs->fs_blkdriver;
if (inode)
{
if (inode->u.i_bops && inode->u.i_bops->close)
{
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 (fs->fs_buffer)
{
fat_io_free(fs->fs_buffer, fs->fs_hwsectorsize);
}
nxmutex_destroy(&fs->fs_lock);
kmm_free(fs);
return OK;
}
/****************************************************************************
* Name: fat_statfs
*
* Description: Return filesystem statistics
*
****************************************************************************/
static int fat_statfs(FAR struct inode *mountpt, FAR struct statfs *buf)
{
FAR struct fat_mountpt_s *fs;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret < 0)
{
goto errout_with_lock;
}
/* Fill in the statfs info */
buf->f_type = MSDOS_SUPER_MAGIC;
/* We will claim that the optimal transfer size is the size of a cluster
* in bytes.
*/
buf->f_bsize = fs->fs_fatsecperclus * fs->fs_hwsectorsize;
/* Everything else follows in units of clusters */
ret = fat_nfreeclusters(fs, &buf->f_bfree); /* Free blocks in the file system */
if (ret >= 0)
{
buf->f_blocks = fs->fs_nclusters; /* Total data blocks in the
* file system */
buf->f_bavail = buf->f_bfree; /* Free blocks avail to non-
* superuser */
#ifdef CONFIG_FAT_LFN
buf->f_namelen = LDIR_MAXFNAME; /* Maximum length of filenames */
#else
buf->f_namelen = (8 + 1 + 3); /* Maximum length of filenames */
#endif
}
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_unlink
*
* Description: Remove a file
*
****************************************************************************/
static int fat_unlink(FAR struct inode *mountpt, FAR const char *relpath)
{
FAR struct fat_mountpt_s *fs;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret == OK)
{
/* If the file is open, the correct behavior is to remove the file
* name, but to keep the file cluster chain in place until the last
* open reference to the file is closed.
*/
/* Remove the file
*
* TODO: Need to defer deleting cluster chain if the file is open.
*/
ret = fat_remove(fs, relpath, false);
}
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_mkdir
*
* Description: Create a directory
*
****************************************************************************/
static int fat_mkdir(FAR struct inode *mountpt, FAR const char *relpath,
mode_t mode)
{
FAR struct fat_mountpt_s *fs;
FAR struct fat_dirinfo_s dirinfo;
FAR uint8_t *direntry;
FAR uint8_t *direntry2;
off_t parentsector;
off_t dirsector;
int32_t dircluster;
uint32_t parentcluster;
uint32_t crtime;
unsigned int i;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Find the directory where the new directory should be created. */
ret = fat_finddirentry(fs, &dirinfo, relpath);
/* Or if any error occurs other -ENOENT, then return the error. For
* example, if one of the earlier directory path segments was not found
* then ENOTDIR will be returned.
*/
if (ret != -ENOENT)
{
/* If anything exists at this location, then we fail with EEXIST */
if (ret == OK)
{
ret = -EEXIST;
}
goto errout_with_lock;
}
/* What we want to see is for fat_finddirentry to fail with -ENOENT.
* This error means that no failure occurred but that nothing exists
* with this name. NOTE: The name has already been set in dirinfo
* structure.
*/
if (ret != -ENOENT)
{
goto errout_with_lock;
}
/* NOTE: There is no check that dirinfo.fd_name contains the final
* directory name. We could be creating an intermediate directory
* in the full relpath.
*/
/* Allocate a directory entry for the new directory in this directory */
ret = fat_allocatedirentry(fs, &dirinfo);
if (ret != OK)
{
goto errout_with_lock;
}
parentsector = fs->fs_currentsector;
/* Allocate a cluster for new directory */
dircluster = fat_createchain(fs);
if (dircluster < 0)
{
ret = dircluster;
goto errout_with_lock;
}
else if (dircluster < 2)
{
ret = -ENOSPC;
goto errout_with_lock;
}
dirsector = fat_cluster2sector(fs, dircluster);
if (dirsector < 0)
{
ret = dirsector;
goto errout_with_lock;
}
/* Flush any existing, dirty data in fs_buffer (because we need
* it to create the directory entries.
*/
ret = fat_fscacheflush(fs);
if (ret < 0)
{
goto errout_with_lock;
}
/* Get a pointer to the first directory entry in the sector */
direntry = fs->fs_buffer;
/* Now erase the contents of fs_buffer */
fs->fs_currentsector = dirsector;
memset(direntry, 0, fs->fs_hwsectorsize);
/* Now clear all sectors in the new directory cluster (except for the
* first).
*/
for (i = 1; i < fs->fs_fatsecperclus; i++)
{
ret = fat_hwwrite(fs, direntry, ++dirsector, 1);
if (ret < 0)
{
goto errout_with_lock;
}
}
/* Now create the "." directory entry in the first directory slot. These
* are special directory entries and are not handled by the normal
* directory management routines.
*/
memset(&direntry[DIR_NAME], ' ', DIR_MAXFNAME);
direntry[DIR_NAME] = '.';
DIR_PUTATTRIBUTES(direntry, FATATTR_DIRECTORY);
crtime = fat_systime2fattime();
DIR_PUTCRTIME(direntry, crtime & 0xffff);
DIR_PUTWRTTIME(direntry, crtime & 0xffff);
DIR_PUTCRDATE(direntry, crtime >> 16);
DIR_PUTWRTDATE(direntry, crtime >> 16);
/* Create ".." directory entry in the second directory slot */
direntry2 = direntry + DIR_SIZE;
/* So far, the two entries are nearly the same */
memcpy(direntry2, direntry, DIR_SIZE);
direntry2[DIR_NAME + 1] = '.';
/* Now add the cluster information to both directory entries */
DIR_PUTFSTCLUSTHI(direntry, dircluster >> 16);
DIR_PUTFSTCLUSTLO(direntry, dircluster);
parentcluster = dirinfo.dir.fd_startcluster;
if (parentcluster == fs->fs_rootbase)
{
parentcluster = 0;
}
DIR_PUTFSTCLUSTHI(direntry2, parentcluster >> 16);
DIR_PUTFSTCLUSTLO(direntry2, parentcluster);
/* Save the first sector of the directory cluster and re-read
* the parentsector
*/
fs->fs_dirty = true;
ret = fat_fscacheread(fs, parentsector);
if (ret < 0)
{
goto errout_with_lock;
}
/* Write the new entry directory entry in the parent directory */
ret = fat_dirwrite(fs, &dirinfo, FATATTR_DIRECTORY, crtime);
if (ret < 0)
{
goto errout_with_lock;
}
/* Set subdirectory start cluster. We assume that fat_dirwrite() did not
* change the sector in the cache.
*/
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
DIR_PUTFSTCLUSTLO(direntry, dircluster);
DIR_PUTFSTCLUSTHI(direntry, dircluster >> 16);
fs->fs_dirty = true;
/* Now update the FAT32 FSINFO sector */
ret = fat_updatefsinfo(fs);
if (ret < 0)
{
goto errout_with_lock;
}
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_rmdir
*
* Description: Remove a directory
*
****************************************************************************/
static int fat_rmdir(FAR struct inode *mountpt, FAR const char *relpath)
{
FAR struct fat_mountpt_s *fs;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret == OK)
{
/* If the directory is open, the correct behavior is to remove the
* directory name, but to keep the directory cluster chain in place
* until the last open reference to the directory is closed.
*/
/* Remove the directory.
*
* TODO: Need to defer deleting cluster chain if the file is open.
*/
ret = fat_remove(fs, relpath, true);
}
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_rename
*
* Description: Rename a file or directory
*
****************************************************************************/
static int fat_rename(FAR struct inode *mountpt, FAR const char *oldrelpath,
FAR const char *newrelpath)
{
FAR struct fat_mountpt_s *fs;
FAR struct fat_dirinfo_s dirinfo;
FAR struct fat_dirseq_s dirseq;
uint8_t *direntry;
uint8_t dirstate[DIR_SIZE - DIR_ATTRIBUTES];
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Find the directory entry for the oldrelpath (there may be multiple
* directory entries if long file name support is enabled).
*/
ret = fat_finddirentry(fs, &dirinfo, oldrelpath);
if (ret != OK)
{
/* Some error occurred -- probably -ENOENT */
goto errout_with_lock;
}
/* One more check: Make sure that the oldrelpath does not refer to the
* root directory. We can't rename the root directory.
*/
if (dirinfo.fd_root)
{
ret = -EXDEV;
goto errout_with_lock;
}
/* Save the information that will need to recover the directory sector and
* directory entry offset to the old directory.
*
* Save the positional information of the old directory entry.
*/
memcpy(&dirseq, &dirinfo.fd_seq, sizeof(struct fat_dirseq_s));
/* Save the non-name-related portion of the directory entry intact */
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
memcpy(dirstate, &direntry[DIR_ATTRIBUTES], DIR_SIZE - DIR_ATTRIBUTES);
/* Now find the directory where we should create the newpath object */
ret = fat_finddirentry(fs, &dirinfo, newrelpath);
/* What we expect is -ENOENT mean that the full directory path was
* followed but that the object does not exists in the terminal directory.
*/
if (ret != -ENOENT)
{
if (ret == OK)
{
/* It is an error if the directory entry at newrelpath already
* exists. The necessary steps to avoid this case should have
* been handled by higher level logic in the VFS.
*/
ret = -EEXIST;
}
goto errout_with_lock;
}
/* Reserve a directory entry. If long file name support is enabled, then
* this might, in fact, allocate a sequence of directory entries. A side
* effect of fat_allocatedirentry() in either case is that it leaves the
* short file name entry in the sector cache.
*/
ret = fat_allocatedirentry(fs, &dirinfo);
if (ret != OK)
{
goto errout_with_lock;
}
/* Then write the new file name into the directory entry. This, of course,
* may involve writing multiple directory entries if long file name
* support is enabled. A side effect of fat_allocatedirentry() in either
* case is that it leaves the short file name entry in the sector cache.
*/
ret = fat_dirnamewrite(fs, &dirinfo);
if (ret < 0)
{
goto errout_with_lock;
}
/* Copy the unchanged information into the new short file name entry. */
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
memcpy(&direntry[DIR_ATTRIBUTES], dirstate, DIR_SIZE - DIR_ATTRIBUTES);
fs->fs_dirty = true;
/* Remove the old entry, flushing the new directory entry to disk. If
* the old file name was a long file name, then multiple directory
* entries may be freed.
*/
ret = fat_freedirentry(fs, &dirseq);
if (ret < 0)
{
goto errout_with_lock;
}
/* Write the old entry to disk and update FSINFO if necessary */
ret = fat_updatefsinfo(fs);
if (ret < 0)
{
goto errout_with_lock;
}
nxmutex_unlock(&fs->fs_lock);
return OK;
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Name: fat_stat_common
*
* Description:
* Common logic used by fat_stat_file() and fat_fstat_root().
*
****************************************************************************/
static int fat_stat_common(FAR struct fat_mountpt_s *fs,
FAR uint8_t *direntry, FAR struct stat *buf)
{
uint16_t fatdate;
uint16_t date2;
uint16_t fattime;
/* Times */
fatdate = DIR_GETWRTDATE(direntry);
fattime = DIR_GETWRTTIME(direntry);
buf->st_mtime = fat_fattime2systime(fattime, fatdate);
date2 = DIR_GETLASTACCDATE(direntry);
if (fatdate == date2)
{
buf->st_atime = buf->st_mtime;
}
else
{
buf->st_atime = fat_fattime2systime(0, date2);
}
fatdate = DIR_GETCRDATE(direntry);
fattime = DIR_GETCRTIME(direntry);
buf->st_ctime = fat_fattime2systime(fattime, fatdate);
/* File/directory size, access block size */
buf->st_size = DIR_GETFILESIZE(direntry);
buf->st_blksize = fs->fs_fatsecperclus * fs->fs_hwsectorsize;
buf->st_blocks = (buf->st_size + buf->st_blksize - 1) / buf->st_blksize;
return OK;
}
/****************************************************************************
* Name: fat_stat_file
*
* Description:
* Function to return the status associated with a file in the FAT file
* system. Used by fat_stat() and fat_fstat().
*
****************************************************************************/
static int fat_stat_file(FAR struct fat_mountpt_s *fs,
FAR uint8_t *direntry, FAR struct stat *buf)
{
uint8_t attribute;
/* Initialize the "struct stat" */
memset(buf, 0, sizeof(struct stat));
/* Get attribute from direntry */
attribute = DIR_GETATTRIBUTES(direntry);
if ((attribute & FATATTR_VOLUMEID) != 0)
{
return -ENOENT;
}
/* Set the access permissions. The file/directory is always readable
* by everyone but may be writeable by no-one.
*/
buf->st_mode = S_IROTH | S_IRGRP | S_IRUSR;
if ((attribute & FATATTR_READONLY) == 0)
{
buf->st_mode |= S_IWOTH | S_IWGRP | S_IWUSR;
}
/* We will report only types file or directory */
if ((attribute & FATATTR_DIRECTORY) != 0)
{
buf->st_mode |= S_IFDIR;
}
else
{
buf->st_mode |= S_IFREG;
}
return fat_stat_common(fs, direntry, buf);
}
/****************************************************************************
* Name: fat_stat_root
*
* Description:
* Logic to stat the root directory. Used by fat_stat().
*
****************************************************************************/
static int fat_stat_root(FAR struct fat_mountpt_s *fs, FAR struct stat *buf)
{
/* Clear the "struct stat" */
memset(buf, 0, sizeof(struct stat));
/* It's directory name of the mount point */
buf->st_mode = S_IFDIR | S_IROTH | S_IRGRP | S_IRUSR | S_IWOTH |
S_IWGRP | S_IWUSR;
return OK;
}
/****************************************************************************
* Name: fat_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int fat_stat(FAR struct inode *mountpt, FAR const char *relpath,
FAR struct stat *buf)
{
FAR struct fat_mountpt_s *fs;
struct fat_dirinfo_s dirinfo;
FAR uint8_t *direntry;
int ret;
/* Sanity checks */
DEBUGASSERT(mountpt && mountpt->i_private);
/* Get the mountpoint private data from the inode structure */
fs = mountpt->i_private;
/* Check if the mount is still healthy */
ret = nxmutex_lock(&fs->fs_lock);
if (ret < 0)
{
return ret;
}
ret = fat_checkmount(fs);
if (ret != OK)
{
goto errout_with_lock;
}
/* Find the directory entry corresponding to relpath. */
ret = fat_finddirentry(fs, &dirinfo, relpath);
/* If nothing was found, then we fail with the reported error */
if (ret < 0)
{
goto errout_with_lock;
}
/* Get the FAT attribute and map it so some meaningful mode_t values */
if (dirinfo.fd_root)
{
ret = fat_stat_root(fs, buf);
}
else
{
/* Get a pointer to the directory entry */
direntry = &fs->fs_buffer[dirinfo.fd_seq.ds_offset];
/* Call fat_stat_file() to create the buf and to save information to
* the stat buffer.
*/
ret = fat_stat_file(fs, direntry, buf);
}
errout_with_lock:
nxmutex_unlock(&fs->fs_lock);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
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