int nxffs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct nxffs_volume_s *volume;
int ret;
fvdbg("cmd: %d arg: %08lx\n", cmd, arg);
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover the file system state from the open file */
volume = filep->f_inode->i_private;
DEBUGASSERT(volume != NULL);
/* Get exclusive access to the volume. Note that the volume exclsem
* protects the open file list.
*/
ret = sem_wait(&volume->exclsem);
if (ret != OK)
{
ret = -errno;
fdbg("sem_wait failed: %d\n", ret);
goto errout;
}
/* Only a reformat and optimize commands are supported */
if (cmd == FIOC_REFORMAT)
{
fvdbg("Reformat command\n");
/* We cannot reformat the volume if there are any open inodes */
if (volume->ofiles)
{
fdbg("Open files\n");
ret = -EBUSY;
goto errout_with_semaphore;
}
/* Re-format the volume -- all is lost */
ret = nxffs_reformat(volume);
}
else if (cmd == FIOC_OPTIMIZE)
{
fvdbg("Optimize command\n");
/* Pack the volume */
ret = nxffs_pack(volume);
}
else
{
/* No other commands supported */
ret = -ENOTTY;
}
errout_with_semaphore:
sem_post(&volume->exclsem);
errout:
return ret;
}
static inline int nxffs_wropen(FAR struct nxffs_volume_s *volume,
FAR const char *name, mode_t oflags,
FAR struct nxffs_ofile_s **ppofile)
{
FAR struct nxffs_wrfile_s *wrfile;
FAR struct nxffs_entry_s entry;
bool packed;
bool truncate = false;
int namlen;
int ret;
/* Limitation: Only a single writer is permitted. Writing may involve
* extension of the file system in FLASH. Since files are contiguous
* in FLASH, only a single file may be extending the FLASH region.
*/
ret = sem_wait(&volume->wrsem);
if (ret != OK)
{
fdbg("ERROR: sem_wait failed: %d\n", ret);
ret = -get_errno();
goto errout;
}
/* Get exclusive access to the volume. Note that the volume exclsem
* protects the open file list. Note that exclsem is ALWAYS taken
* after wrsem to avoid deadlocks.
*/
ret = sem_wait(&volume->exclsem);
if (ret != OK)
{
fdbg("ERROR: sem_wait failed: %d\n", ret);
ret = -get_errno();
goto errout_with_wrsem;
}
/* Check if the file exists */
ret = nxffs_findinode(volume, name, &entry);
if (ret == OK)
{
FAR struct nxffs_ofile_s *ofile;
/* It exists. Release the entry. */
nxffs_freeentry(&entry);
/* Is the file already open for reading? */
ofile = nxffs_findofile(volume, name);
if (ofile)
{
/* The file is already open.
* Limitation: Files cannot be open both for reading and writing.
*/
fdbg("ERROR: File is open for reading\n");
ret = -ENOSYS;
goto errout_with_exclsem;
}
/* It would be an error if we are asked to create the file
* exclusively.
*/
else if ((oflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
{
fdbg("ERROR: File exists, can't create O_EXCL\n");
ret = -EEXIST;
goto errout_with_exclsem;
}
/* Were we asked to truncate the file? NOTE: Don't truncate the
* file if we were not also asked to created it. See below...
* we will not re-create the file unless O_CREAT is also specified.
*/
else if ((oflags & (O_CREAT|O_TRUNC)) == (O_CREAT|O_TRUNC))
{
/* Just schedule the removal the file and fall through to re-create it.
* Note that the old file of the same name will not actually be removed
* until the new file is successfully written.
*/
truncate = true;
}
/* The file exists and we were not asked to truncate (and recreate) it.
* Limitation: Cannot write to existing files.
*/
else
{
fdbg("ERROR: File %s exists and we were not asked to truncate it\n");
ret = -ENOSYS;
goto errout_with_exclsem;
}
}
/* Okay, the file is not open and does not exists (maybe because we deleted
* it). Now, make sure that we were asked to created it.
*/
if ((oflags & O_CREAT) == 0)
{
fdbg("ERROR: Not asked to create the file\n");
ret = -ENOENT;
goto errout_with_exclsem;
}
/* Make sure that the length of the file name will fit in a uint8_t */
namlen = strlen(name);
if (namlen > CONFIG_NXFFS_MAXNAMLEN)
{
fdbg("ERROR: Name is too long: %d\n", namlen);
ret = -EINVAL;
goto errout_with_exclsem;
}
/* Yes.. Create a new structure that will describe the state of this open
* file. NOTE that a special variant of the open file structure is used
* that includes additional information to support the write operation.
*/
#ifdef CONFIG_NXFFS_PREALLOCATED
wrfile = &g_wrfile;
memset(wrfile, 0, sizeof(struct nxffs_wrfile_s));
#else
wrfile = (FAR struct nxffs_wrfile_s *)kmm_zalloc(sizeof(struct nxffs_wrfile_s));
if (!wrfile)
{
ret = -ENOMEM;
goto errout_with_exclsem;
}
#endif
/* Initialize the open file state structure */
wrfile->ofile.crefs = 1;
wrfile->ofile.oflags = oflags;
wrfile->ofile.entry.utc = time(NULL);
wrfile->truncate = truncate;
/* Save a copy of the inode name. */
wrfile->ofile.entry.name = strdup(name);
if (!wrfile->ofile.entry.name)
{
ret = -ENOMEM;
goto errout_with_ofile;
}
/* Allocate FLASH memory for the file and set up for the write.
*
* Loop until the inode header is configured or until a failure occurs.
* Note that nothing is written to FLASH. The inode header is not
* written until the file is closed.
*/
packed = false;
for (;;)
{
/* File a valid location to position the inode header. Start with the
* first byte in the free FLASH region.
*/
ret = nxffs_hdrpos(volume, wrfile);
if (ret == OK)
{
/* Find a region of memory in the block that is fully erased */
ret = nxffs_hdrerased(volume, wrfile);
if (ret == OK)
{
/* Valid memory for the inode header was found. Break out of
* the loop.
*/
break;
}
}
/* If no valid memory is found searching to the end of the volume,
* then -ENOSPC will be returned. Other errors are not handled.
*/
if (ret != -ENOSPC || packed)
{
fdbg("ERROR: Failed to find inode header memory: %d\n", -ret);
goto errout_with_name;
}
/* -ENOSPC is a special case.. It means that the volume is full.
* Try to pack the volume in order to free up some space.
*/
ret = nxffs_pack(volume);
if (ret < 0)
{
fdbg("ERROR: Failed to pack the volume: %d\n", -ret);
goto errout_with_name;
}
/* After packing the volume, froffset will be updated to point to the
* new free flash region. Try again.
*/
packed = true;
}
/* Loop until the inode name is configured or until a failure occurs.
* Note that nothing is written to FLASH.
*/
for (;;)
{
/* File a valid location to position the inode name. Start with the
* first byte in the free FLASH region.
*/
ret = nxffs_nampos(volume, wrfile, namlen);
if (ret == OK)
{
/* Find a region of memory in the block that is fully erased */
ret = nxffs_namerased(volume, wrfile, namlen);
if (ret == OK)
{
/* Valid memory for the inode header was found. Write the
* inode name to this location.
*/
ret = nxffs_wrname(volume, &wrfile->ofile.entry, namlen);
if (ret < 0)
{
fdbg("ERROR: Failed to write the inode name: %d\n", -ret);
goto errout_with_name;
}
/* Then just break out of the loop reporting success. Note
* that the alllocated inode name string is retained; it
* will be needed later to calculate the inode CRC.
*/
break;
}
}
/* If no valid memory is found searching to the end of the volume,
* then -ENOSPC will be returned. Other errors are not handled.
*/
if (ret != -ENOSPC || packed)
{
fdbg("ERROR: Failed to find inode name memory: %d\n", -ret);
goto errout_with_name;
}
/* -ENOSPC is a special case.. It means that the volume is full.
* Try to pack the volume in order to free up some space.
*/
ret = nxffs_pack(volume);
if (ret < 0)
{
fdbg("ERROR: Failed to pack the volume: %d\n", -ret);
goto errout_with_name;
}
/* After packing the volume, froffset will be updated to point to the
* new free flash region. Try again.
*/
packed = true;
}
/* Add the open file structure to the head of the list of open files */
wrfile->ofile.flink = volume->ofiles;
volume->ofiles = &wrfile->ofile;
/* Indicate that the volume is open for writing and return the open file
* instance. Releasing exclsem allows other readers while the write is
* in progress. But wrsem is still held for this open file, preventing
* any further writers until this inode is closed.s
*/
*ppofile = &wrfile->ofile;
sem_post(&volume->exclsem);
return OK;
errout_with_name:
kmm_free(wrfile->ofile.entry.name);
errout_with_ofile:
#ifndef CONFIG_NXFFS_PREALLOCATED
kmm_free(wrfile);
#endif
errout_with_exclsem:
sem_post(&volume->exclsem);
errout_with_wrsem:
sem_post(&volume->wrsem);
errout:
return ret;
}
static inline int nxffs_wralloc(FAR struct nxffs_volume_s *volume,
FAR struct nxffs_wrfile_s *wrfile,
size_t size)
{
bool packed;
int ret;
/* Allocate FLASH memory for the data block.
*
* Loop until the data block header is configured or until a failure
* occurs. Note that nothing is written to FLASH. The data block header
* is not written until either (1) the file is closed, or (2) the data
* region is fully populated.
*/
packed = false;
for (;;)
{
size_t mindata = MIN(NXFFS_MINDATA, size);
/* File a valid location to position the data block. Start with
* the first byte in the free FLASH region.
*/
ret = nxffs_hdrpos(volume, wrfile, mindata);
if (ret == OK)
{
/* Find a region of memory in the block that is fully erased */
ret = nxffs_hdrerased(volume, wrfile, mindata);
if (ret == OK)
{
/* Valid memory for the data block was found. Return success. */
return OK;
}
}
/* If no valid memory is found searching to the end of the volume,
* then -ENOSPC will be returned. Other errors are not handled.
*/
if (ret != -ENOSPC || packed)
{
fdbg("ERROR: Failed to find inode header memory: %d\n", -ret);
return -ENOSPC;
}
/* -ENOSPC is a special case.. It means that the volume is full.
* Try to pack the volume in order to free up some space.
*/
ret = nxffs_pack(volume);
if (ret < 0)
{
fdbg("ERROR: Failed to pack the volume: %d\n", -ret);
return ret;
}
/* After packing the volume, froffset will be updated to point to the
* new free flash region. Try again.
*/
nxffs_ioseek(volume, volume->froffset);
packed = true;
}
/* Can't get here */
return OK;
}
