/**************************************************************************** * fs/nxffs/nxffs_initialize.c * * Copyright (C) 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #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; sem_init(&volume->exclsem, 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, in-memory erase block buffer */ volume->cache = (FAR uint8_t *)kmalloc(volume->geo.erasesize); if (!volume->cache) { fdbg("Failed to allocate an erase block buffer\n"); ret = -ENOMEM; goto errout_with_volume; } /* 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_iobuffer; } /* 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_iobuffer; } /* 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_iobuffer; } #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_iobuffer: kfree(volume->cache); errout_with_volume: kfree(volume); 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 using the rw data * length as the offset increment. This is, of course, not accurate * because it does not account for the data headers that enclose the * data. But it is guaranteed to be less than or equal to the * correct offset and, hence, better then searching byte-for-byte. */ offset = entry.doffset + entry.datlen; 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 (see comments above). */ offset = entry.doffset + entry.datlen; 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); if (ch < 0) { /* Failed to read the next byte... this could mean that the FLASH * is full? */ fvdbg("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 }