diff options
Diffstat (limited to 'nuttx/fs/nxffs/nxffs_block.c')
-rw-r--r-- | nuttx/fs/nxffs/nxffs_block.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_block.c b/nuttx/fs/nxffs/nxffs_block.c new file mode 100644 index 000000000..a069048b8 --- /dev/null +++ b/nuttx/fs/nxffs/nxffs_block.c @@ -0,0 +1,186 @@ +/**************************************************************************** + * fs/nxffs/nxffs_block.c + * + * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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/mtd.h> + +#include "nxffs.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Public Types + ****************************************************************************/ + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nxffs_verifyblock + * + * Description: + * Assure the the provided (logical) block number is in the block cache + * and that it has a valid block header (i.e., proper magic and + * marked good) + * + * Input Parameters: + * volume - Describes the NXFFS volume + * block - The (logical) block number to load and verify. + * + * Returned Values: + * Zero is returned on success. Otherwise, a negated errno value is + * returned indicating the nature of the failure. -ENOENT is returned + * if the block is a bad block. + * + ****************************************************************************/ + +int nxffs_verifyblock(FAR struct nxffs_volume_s *volume, off_t block) +{ + FAR struct nxffs_block_s *blkhdr; + int ret; + + /* Make sure the the block is in the cache */ + + ret = nxffs_rdcache(volume, block); + if (ret < 0) + { + /* Perhaps we are at the end of the media */ + + fvdbg("Failed to read data into cache: %d\n", ret); + return ret; + } + + /* Check if the block has a magic number (meaning that it is not + * erased) and that it is valid (meaning that it is not marked + * for deletion) + */ + + blkhdr = (FAR struct nxffs_block_s *)volume->cache; + if (memcmp(blkhdr->magic, g_blockmagic, NXFFS_MAGICSIZE) == 0) + { + /* This does appear to be a block */ + + if (blkhdr->state == BLOCK_STATE_GOOD) + { + /* The block is valid */ + + return OK; + } + else if (blkhdr->state == BLOCK_STATE_BAD) + { + /* -ENOENT is a special indication that this is a properly marked + * bad block + */ + + return -ENOENT; + } + } + + /* Whatever is here where a block header should be is invalid */ + + return -EINVAL; +} + +/**************************************************************************** + * Name: nxffs_validblock + * + * Description: + * Find the next valid (logical) block in the volume. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * block - On entry, this provides the starting block number. If the + * function is succesfful, then this memory location will hold the + * block number of the next valid block on return. + * + * Returned Value: + * Zero on success otherwise a negated errno value indicating the nature + * of the failure. + * + ****************************************************************************/ + +int nxffs_validblock(struct nxffs_volume_s *volume, off_t *block) +{ + off_t i; + int ret; + + DEBUGASSERT(volume && block); + + /* Loop for each possible block or until a valid block is found */ + + for (i = *block; i < volume->nblocks; i++) + { + /* Loop until we find a valid block */ + + ret = nxffs_verifyblock(volume, i); + if (ret == OK) + { + /* We found it, return the block number */ + + *block = i; + return OK; + } + } + + /* ENOSPC is special return value that means that there is no further, + * valid blocks left in the volume. + */ + + fdbg("No valid block found\n"); + return -ENOSPC; +} |