diff options
Diffstat (limited to 'nuttx/fs/nxffs/nxffs_initialize.c')
-rw-r--r-- | nuttx/fs/nxffs/nxffs_initialize.c | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_initialize.c b/nuttx/fs/nxffs/nxffs_initialize.c new file mode 100644 index 000000000..6d93a318a --- /dev/null +++ b/nuttx/fs/nxffs/nxffs_initialize.c @@ -0,0 +1,520 @@ +/**************************************************************************** + * fs/nxffs/nxffs_initialize.c + * + * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * References: Linux/Documentation/filesystems/romfs.txt + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <string.h> +#include <errno.h> +#include <assert.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/mtd.h> +#include <nuttx/fs/fs.h> +#include <nuttx/fs/ioctl.h> + +#include "nxffs.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/* See fs_mount.c -- this structure is explicitly externed there. + * We use the old-fashioned kind of initializers so that this will compile + * with any compiler. + */ + +const struct mountpt_operations 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, /* sync -- No buffered data */ + + nxffs_opendir, /* opendir */ + NULL, /* 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 */ +}; + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/* 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_NXFSS_PREALLOCATED is defined, then this is the single, pre- + * allocated NXFFS volume instance. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED +struct nxffs_volume_s g_volume; +#endif + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * 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; + struct nxffs_blkstats_s stats; + off_t threshold; + int ret; + + /* If CONFIG_NXFSS_PREALLOCATED is defined, then this is the single, pre- + * allocated NXFFS volume instance. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED + + volume = &g_volume; + memset(volume, 0, sizeof(struct nxffs_volume_s)); + +#else + + /* Allocate a NXFFS volume structure */ + + volume = (FAR struct nxffs_volume_s *)kzalloc(sizeof(struct nxffs_volume_s)); + if (!volume) + { + ret = -ENOMEM; + goto errout; + } +#endif + + /* Initialize the NXFFS volume structure */ + + volume->mtd = mtd; + volume->cblock = (off_t)-1; + sem_init(&volume->exclsem, 0, 1); + sem_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) + { + fdbg("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 = (FAR uint8_t *)kmalloc(volume->geo.blocksize); + if (!volume->cache) + { + fdbg("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 = (FAR uint8_t *)kmalloc(volume->geo.erasesize); + if (!volume->pack) + { + fdbg("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); + + /* Check if there is a valid NXFFS file system on the flash */ + + ret = nxffs_blockstats(volume, &stats); + if (ret < 0) + { + fdbg("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 / 5; + if (stats.ngood < threshold || stats.nunformat > threshold) + { + /* Reformat the volume */ + + ret = nxffs_reformat(volume); + if (ret < 0) + { + fdbg("Failed to reformat the volume: %d\n", -ret); + goto errout_with_buffer; + } + + /* Get statistics on the re-formatted volume */ + +#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_FS) + ret = nxffs_blockstats(volume, &stats); + if (ret < 0) + { + fdbg("Failed to collect block statistics: %d\n", -ret); + goto errout_with_buffer; + } +#endif + } + + /* Get the file system limits */ + + ret = nxffs_limits(volume); + if (ret == OK) + { + return OK; + } + fdbg("Failed to calculate file system limits: %d\n", -ret); + +errout_with_buffer: + kfree(volume->pack); +errout_with_cache: + kfree(volume->cache); +errout_with_volume: +#ifndef CONFIG_NXFSS_PREALLOCATED + kfree(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) + { + fdbg("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) + { + fdbg("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. + */ + + fvdbg("No inodes found\n"); + noinodes = true; + } + else + { + /* Save the offset to the first inode */ + + volume->inoffset = entry.hoffset; + fvdbg("First inode at offset %d\n", 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 ((ret = nxffs_nextentry(volume, offset, &entry)) == OK) + { + /* Discard the entry and guess the next offset. */ + + offset = nxffs_inodeend(volume, &entry); + nxffs_freeentry(&entry); + } + fvdbg("Last inode before offset %d\n", 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; + fvdbg("Assume no free FLASH, froffset: %d\n", volume->froffset); + if (noinodes) + { + volume->inoffset = volume->froffset; + fvdbg("No inodes, inoffset: %d\n", volume->inoffset); + } + return OK; + } + + // No? Then it is some other failure that we do not know how to handle + + fdbg("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; + fvdbg("Free FLASH region begins at offset: %d\n", volume->froffset); + if (noinodes) + { + volume->inoffset = offset; + fvdbg("First inode at offset %d\n", 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_NXFSS_PREALLOCATED +# error "No design to support dynamic allocation of volumes" +#else + + /* If CONFIG_NXFSS_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) +{ +#ifndef CONFIG_NXFSS_PREALLOCATED +# error "No design to support dynamic allocation of volumes" +#else + return g_volume.ofiles ? -EBUSY : OK; +#endif +} |