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incubator-nuttx/fs/nxffs/nxffs_initialize.c

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/****************************************************************************
* fs/nxffs/nxffs_initialize.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 <stdint.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mtd/mtd.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/ioctl.h>
#include "nxffs.h"
/****************************************************************************
* Private Data
****************************************************************************/
/* See fs_mount.c -- this structure is explicitly externed there.
* We use the old-fashioned kind of initializers so that this will compile
* with any compiler.
*/
const struct mountpt_operations g_nxffs_operations =
{
nxffs_open, /* open */
nxffs_close, /* close */
nxffs_read, /* read */
nxffs_write, /* write */
NULL, /* seek -- Use f_pos in struct file */
nxffs_ioctl, /* ioctl */
NULL, /* mmap */
#ifdef __NO_TRUNCATE_SUPPORT__
nxffs_truncate, /* truncate */
#else
NULL, /* truncate */
#endif
NULL, /* poll */
NULL, /* sync -- No buffered data */
nxffs_dup, /* dup */
nxffs_fstat, /* fstat */
NULL, /* fchstat */
nxffs_opendir, /* opendir */
nxffs_closedir, /* closedir */
nxffs_readdir, /* readdir */
nxffs_rewinddir, /* rewinddir */
nxffs_bind, /* bind */
nxffs_unbind, /* unbind */
nxffs_statfs, /* statfs */
nxffs_unlink, /* unlink */
NULL, /* mkdir -- no directories */
NULL, /* rmdir -- no directories */
NULL, /* rename -- cannot rename in place if name is longer */
nxffs_stat, /* stat */
NULL /* chstat */
};
/****************************************************************************
* Public Data
****************************************************************************/
/* The magic number that appears that the beginning of each NXFFS (logical)
* block
*/
const uint8_t g_blockmagic[NXFFS_MAGICSIZE] =
{
'B', 'l', 'c', 'k'
};
/* The magic number that appears that the beginning of each NXFFS inode */
const uint8_t g_inodemagic[NXFFS_MAGICSIZE] =
{
'I', 'n', 'o', 'd'
};
/* The magic number that appears that the beginning of each NXFFS inode
* data block.
*/
const uint8_t g_datamagic[NXFFS_MAGICSIZE] =
{
'D', 'a', 't', 'a'
};
/* If CONFIG_NXFFS_PREALLOCATED is defined, then this is the single, pre-
* allocated NXFFS volume instance.
*/
#ifdef CONFIG_NXFFS_PREALLOCATED
struct nxffs_volume_s g_volume;
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxffs_initialize
*
* Description:
* Initialize to provide NXFFS on an MTD interface
*
* Input Parameters:
* mtd - The MTD device that supports the FLASH interface.
*
* Returned Value:
* Zero is returned on success. Otherwise, a negated errno value is
* returned to indicate the nature of the failure.
*
****************************************************************************/
int nxffs_initialize(FAR struct mtd_dev_s *mtd)
{
FAR struct nxffs_volume_s *volume;
#ifdef CONFIG_NXFFS_SCAN_VOLUME
struct nxffs_blkstats_s stats;
off_t threshold;
#endif
int ret;
/* If CONFIG_NXFFS_PREALLOCATED is defined, then this is the single, pre-
* allocated NXFFS volume instance.
*/
#ifdef CONFIG_NXFFS_PREALLOCATED
volume = &g_volume;
memset(volume, 0, sizeof(struct nxffs_volume_s));
#else
/* Allocate a NXFFS volume structure */
volume = kmm_zalloc(sizeof(struct nxffs_volume_s));
if (!volume)
{
return -ENOMEM;
}
#endif
/* Initialize the NXFFS volume structure */
volume->mtd = mtd;
volume->cblock = (off_t)-1;
nxmutex_init(&volume->lock);
nxsem_init(&volume->wrsem, 0, 1);
/* Get the volume geometry. (casting to uintptr_t first eliminates
* complaints on some architectures where the sizeof long is different
* from the size of a pointer).
*/
ret = MTD_IOCTL(mtd, MTDIOC_GEOMETRY,
(unsigned long)((uintptr_t)&volume->geo));
if (ret < 0)
{
ferr("ERROR: MTD ioctl(MTDIOC_GEOMETRY) failed: %d\n", -ret);
goto errout_with_volume;
}
/* Allocate one I/O block buffer to general files system access */
volume->cache = kmm_malloc(volume->geo.blocksize);
if (!volume->cache)
{
ferr("ERROR: Failed to allocate an erase block buffer\n");
ret = -ENOMEM;
goto errout_with_volume;
}
/* Pre-allocate one, full, in-memory erase block. This is needed for
* filesystem packing (but is useful in other places as well). This buffer
* is not needed often, but is best to have pre-allocated and in-place.
*/
volume->pack = kmm_malloc(volume->geo.erasesize);
if (!volume->pack)
{
ferr("ERROR: Failed to allocate an I/O block buffer\n");
ret = -ENOMEM;
goto errout_with_cache;
}
/* Get the number of R/W blocks per erase block and the total number o
* R/W blocks
*/
volume->blkper = volume->geo.erasesize / volume->geo.blocksize;
volume->nblocks = volume->geo.neraseblocks * volume->blkper;
DEBUGASSERT((off_t)volume->blkper * volume->geo.blocksize ==
volume->geo.erasesize);
#ifdef CONFIG_NXFFS_SCAN_VOLUME
/* Check if there is a valid NXFFS file system on the flash */
ret = nxffs_blockstats(volume, &stats);
if (ret < 0)
{
ferr("ERROR: Failed to collect block statistics: %d\n", -ret);
goto errout_with_buffer;
}
/* If the proportion of good blocks is low or the proportion of unformatted
* blocks is high, then reformat the FLASH.
*/
threshold = (stats.nblocks * CONFIG_NXFFS_REFORMAT_THRESH) / 100;
if (stats.ngood < threshold || stats.nunformat > threshold)
{
/* Reformat the volume */
ret = nxffs_reformat(volume);
if (ret < 0)
{
ferr("ERROR: Failed to reformat the volume: %d\n", -ret);
goto errout_with_buffer;
}
/* Get statistics on the re-formatted volume */
#if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_DEBUG_FS)
ret = nxffs_blockstats(volume, &stats);
if (ret < 0)
{
ferr("ERROR: Failed to collect block statistics: %d\n", -ret);
goto errout_with_buffer;
}
#endif
}
#endif /* CONFIG_NXFFS_SCAN_VOLUME */
/* Get the file system limits */
ret = nxffs_limits(volume);
if (ret == OK)
{
return OK;
}
/* We may need to format the volume. Try that before giving up. */
fwarn("WARNING: Failed to calculate file system limits: %d\n", -ret);
ret = nxffs_reformat(volume);
if (ret < 0)
{
ferr("ERROR: Failed to reformat the volume: %d\n", -ret);
goto errout_with_buffer;
}
/* Get statistics on the re-formatted volume */
#if defined(CONFIG_NXFFS_SCAN_VOLUME) && defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_DEBUG_FS)
ret = nxffs_blockstats(volume, &stats);
if (ret < 0)
{
ferr("ERROR: Failed to collect block statistics: %d\n", -ret);
goto errout_with_buffer;
}
#endif
/* Now try to get the file system limits again */
ret = nxffs_limits(volume);
if (ret == OK)
{
return OK;
}
/* Now give up */
ferr("ERROR: Failed to calculate file system limits: %d\n", -ret);
errout_with_buffer:
kmm_free(volume->pack);
errout_with_cache:
kmm_free(volume->cache);
errout_with_volume:
nxmutex_destroy(&volume->lock);
nxsem_destroy(&volume->wrsem);
#ifndef CONFIG_NXFFS_PREALLOCATED
kmm_free(volume);
#endif
return ret;
}
/****************************************************************************
* Name: nxffs_limits
*
* Description:
* Recalculate file system limits: (1) the FLASH offset to the first,
* valid inode, and (2) the FLASH offset to the first, unused byte after
* the last inode (invalid or not).
*
* The first, lower limit must be recalculated: (1) initially, (2)
* whenever the first inode is deleted, or (3) whenever inode is moved
* as part of the file system packing operation.
*
* The second, upper limit must be (1) incremented whenever new file
* data is written, or (2) recalculated as part of the file system packing
* operation.
*
* Input Parameters:
* volume - Identifies the NXFFS volume
*
* Returned Value:
* Zero on success. Otherwise, a negated error is returned indicating the
* nature of the failure.
*
****************************************************************************/
int nxffs_limits(FAR struct nxffs_volume_s *volume)
{
FAR struct nxffs_entry_s entry;
off_t block;
off_t offset;
bool noinodes = false;
int nerased;
int ret;
/* Get the offset to the first valid block on the FLASH */
block = 0;
ret = nxffs_validblock(volume, &block);
if (ret < 0)
{
ferr("ERROR: Failed to find a valid block: %d\n", -ret);
return ret;
}
/* Then find the first valid inode in or beyond the first valid block */
offset = block * volume->geo.blocksize;
ret = nxffs_nextentry(volume, offset, &entry);
if (ret < 0)
{
/* The value -ENOENT is special. This simply means that the FLASH
* was searched to the end and no valid inode was found... the file
* system is empty (or, in more perverse cases, all inodes are
* deleted or corrupted).
*/
if (ret != -ENOENT)
{
ferr("ERROR: nxffs_nextentry failed: %d\n", -ret);
return ret;
}
/* Set a flag the just indicates that no inodes were found. Later,
* we will set the location of the first inode to be the same as
* the location of the free FLASH region.
*/
finfo("No inodes found\n");
noinodes = true;
}
else
{
/* Save the offset to the first inode */
volume->inoffset = entry.hoffset;
finfo("First inode at offset %jd\n", (intmax_t)volume->inoffset);
/* Discard this entry and set the next offset. */
offset = nxffs_inodeend(volume, &entry);
nxffs_freeentry(&entry);
}
/* Now, search for the last valid entry */
if (!noinodes)
{
while (nxffs_nextentry(volume, offset, &entry) == OK)
{
/* Discard the entry and guess the next offset. */
offset = nxffs_inodeend(volume, &entry);
nxffs_freeentry(&entry);
}
finfo("Last inode before offset %jd\n", (intmax_t)offset);
}
/* No inodes were found after this offset. Now search for a block of
* erased flash.
*/
nxffs_ioseek(volume, offset);
nerased = 0;
for (; ; )
{
int ch = nxffs_getc(volume, 1);
if (ch < 0)
{
/* Failed to read the next byte... this could mean that the FLASH
* is full?
*/
if (volume->ioblock + 1 >= volume->nblocks &&
volume->iooffset + 1 >= volume->geo.blocksize)
{
/* Yes.. the FLASH is full. Force the offsets to the end of
* FLASH
*/
volume->froffset = volume->nblocks * volume->geo.blocksize;
finfo("Assume no free FLASH, froffset: %jd\n",
(intmax_t)volume->froffset);
if (noinodes)
{
volume->inoffset = volume->froffset;
finfo("No inodes, inoffset: %jd\n",
(intmax_t)volume->inoffset);
}
return OK;
}
/* No? Then it is some other failure that we do not know how to
* handle
*/
ferr("ERROR: nxffs_getc failed: %d\n", -ch);
return ch;
}
/* Check for another erased byte */
else if (ch == CONFIG_NXFFS_ERASEDSTATE)
{
/* If we have encountered NXFFS_NERASED number of consecutive
* erased bytes, then presume we have reached the end of valid
* data.
*/
if (++nerased >= NXFFS_NERASED)
{
/* Okay.. we have a long stretch of erased FLASH in a valid
* FLASH block. Let's say that this is the beginning of
* the free FLASH region.
*/
volume->froffset = offset;
finfo("Free FLASH region begins at offset: %jd\n",
(intmax_t)volume->froffset);
if (noinodes)
{
volume->inoffset = offset;
finfo("First inode at offset %jd\n",
(intmax_t)volume->inoffset);
}
return OK;
}
}
else
{
offset += nerased + 1;
nerased = 0;
}
}
/* Won't get here */
return OK;
}
/****************************************************************************
* Name: nxffs_bind
*
* Description:
* This function implements a portion of the mount operation. Normmally,
* the bind() method allocates and initializes the mountpoint private data
* then 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().
*
* For the NXFFS, this sequence is quite different for the following
* reasons:
*
* 1. A block driver is not used. Instead, an MTD instance was provided
* to nxfs_initialize prior to mounting. So, in this sense, the NXFFS
* file system is already bound.
*
* 2. Since the volume was already bound to the MTD driver, all allocations
* and initializations have already been performed. Essentially, all
* mount operations have been bypassed and now we just need to provide
* the pre-allocated volume instance.
*
* 3. The tricky thing is that there is no mechanism to associate multiple
* NXFFS volumes to the multiple volumes bound to different MTD drivers.
* Hence, the limitation of a single NXFFS volume.
*
****************************************************************************/
int nxffs_bind(FAR struct inode *blkdriver, FAR const void *data,
FAR void **handle)
{
#ifndef CONFIG_NXFFS_PREALLOCATED
# error "No design to support dynamic allocation of volumes"
#else
/* If CONFIG_NXFFS_PREALLOCATED is defined, then this is the single, pre-
* allocated NXFFS volume instance.
*/
DEBUGASSERT(g_volume.cache);
*handle = &g_volume;
#endif
return OK;
}
/****************************************************************************
* Name: nxffs_unbind
*
* Description: This implements the filesystem portion of the umount
* operation.
*
****************************************************************************/
int nxffs_unbind(FAR void *handle, FAR struct inode **blkdriver,
unsigned int flags)
{
#ifndef CONFIG_NXFFS_PREALLOCATED
# error "No design to support dynamic allocation of volumes"
#else
/* This implementation currently only supports unmounting if there are no
* open file references.
*/
if (flags != 0)
{
return -ENOSYS;
}
return g_volume.ofiles ? -EBUSY : OK;
#endif
}
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