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diff --git a/nuttx/fs/nxffs/nxffs.h b/nuttx/fs/nxffs/nxffs.h new file mode 100644 index 000000000..616dc7197 --- /dev/null +++ b/nuttx/fs/nxffs/nxffs.h @@ -0,0 +1,1083 @@ +/**************************************************************************** + * fs/nxffs/nxffs.h + * + * 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. + * + ****************************************************************************/ + +#ifndef __FS_NXFFS_NXFFS_H +#define __FS_NXFFS_NXFFS_H + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <stdbool.h> +#include <semaphore.h> + +#include <nuttx/mtd.h> +#include <nuttx/fs/nxffs.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ +/* NXFFS Definitions ********************************************************/ +/* General NXFFS organization. The following example assumes 4 logical + * blocks per FLASH erase block. The actual relationship is determined by + * the FLASH geometry reported by the MTD driver. + * + * ERASE LOGICAL Inodes begin with a inode header. inode may + * BLOCK BLOCK CONTENTS be marked as "deleted," pending re-packing. + * n 4*n --+--------------+ + * |BBBBBBBBBBBBBB| Logic block header + * |IIIIIIIIIIIIII| Inodes begin with a inode header + * |DDDDDDDDDDDDDD| Data block containing inode data block + * | (Inode Data) | + * 4*n+1 --+--------------+ + * |BBBBBBBBBBBBBB| Logic block header + * |DDDDDDDDDDDDDD| Inodes may consist of multiple data blocks + * | (Inode Data) | + * |IIIIIIIIIIIIII| Next inode header + * | | Possibly a few unused bytes at the end of a block + * 4*n+2 --+--------------+ + * |BBBBBBBBBBBBBB| Logic block header + * |DDDDDDDDDDDDDD| + * | (Inode Data) | + * 4*n+3 --+--------------+ + * |BBBBBBBBBBBBBB| Logic block header + * |IIIIIIIIIIIIII| Next inode header + * |DDDDDDDDDDDDDD| + * | (Inode Data) | + * n+1 4*(n+1) --+--------------+ + * |BBBBBBBBBBBBBB| Logic block header + * | | All FLASH is unused after the end of the final + * | | inode. + * --+--------------+ + * + * General operation: + * Inodes are written starting at the beginning of FLASH. As inodes are + * deleted, they are marked as deleted but not removed. As new inodes are + * written, allocations proceed to toward the end of the FLASH -- thus, + * supporting wear leveling by using all FLASH blocks equally. + * + * When the FLASH becomes full (no more space at the end of the FLASH), a + * re-packing operation must be performed: All inodes marked deleted are + * finally removed and the remaining inodes are packed at the beginning of + * the FLASH. Allocations then continue at the freed FLASH memory at the + * end of the FLASH. + * + * BLOCK HEADER: + * The block header is used to determine if the block has every been + * formatted and also indicates bad blocks which should never be used. + * + * INODE HEADER: + * Each inode begins with an inode header that contains, among other things, + * the name of the inode, the offset to the first data block, and the + * length of the inode data. + * + * At present, the only kind of inode support is a file. So for now, the + * term file and inode are interchangeable. + * + * INODE DATA HEADER: + * Inode data is enclosed in a data header. For a given inode, there + * is at most one inode data block per logical block. If the inode data + * spans more than one logical block, then the inode data may be enclosed + * in multiple data blocks, one per logical block. + * + * NXFFS Limitations: + * 1. Since the files are contiguous in FLASH and since allocations always + * proceed toward the end of the FLASH, there can only be one file opened + * for writing at a time. Multiple files may be opened for reading. + * 2. Files may not be increased in size after they have been closed. The + * O_APPEND open flag is not supported. + * 3. Files are always written sequential. Seeking within a file opened for + * writing will not work. + * 4. There are no directories, however, '/' may be used within a file name + * string providing some illusion of directories. + * 5. Files may be opened for reading or for writing, but not both: The O_RDWR + * open flag is not supported. + * 6. The re-packing process occurs only during a write when the free FLASH + * memory at the end of the FLASH is exhausted. Thus, occasionally, file + * writing may take a long time. + * 7. Another limitation is that there can be only a single NXFFS volume + * mounted at any time. This has to do with the fact that we bind to + * an MTD driver (instead of a block driver) and bypass all of the normal + * mount operations. + */ + +/* Values for logical block state. Basically, there are only two, perhaps + * three, states: + * + * BLOCK_STATE_GOOD - The block is not known to be bad. + * BLOCK_STATE_BAD - An error was found on the block and it is marked bad. + * Other values - The block is bad and has an invalid state. + * + * Care is taken so that the GOOD to BAD transition only involves burning + * bits from the erased to non-erased state. + */ + +#define BLOCK_STATE_GOOD (CONFIG_NXFFS_ERASEDSTATE ^ 0x44) +#define BLOCK_STATE_BAD (CONFIG_NXFFS_ERASEDSTATE ^ 0x55) + +/* Values for NXFFS inode state. Similar there are 2 (maybe 3) inode states: + * + * INODE_STATE_FILE - The inode is a valid usuable, file + * INODE_STATE_DELETED - The inode has been deleted. + * Other values - The inode is bad and has an invalid state. + * + * Care is taken so that the VALID to DELETED transition only involves burning + * bits from the erased to non-erased state. + */ + +#define INODE_STATE_FILE (CONFIG_NXFFS_ERASEDSTATE ^ 0x22) +#define INODE_STATE_DELETED (CONFIG_NXFFS_ERASEDSTATE ^ 0xaa) + +/* Number of bytes in an the NXFFS magic sequences */ + +#define NXFFS_MAGICSIZE 4 + +/* When we allocate FLASH for a new inode data block, we will require that + * space is available to hold this minimum number of data bytes in addition + * to the size of the data block headeer. + */ + +#define NXFFS_MINDATA 16 + +/* Internal definitions *****************************************************/ +/* If we encounter this number of erased bytes, we assume that all of the + * flash beyond this point is erased. + */ + +#define NXFFS_NERASED 128 + +/* Quasi-standard definitions */ + +#ifndef MIN +# define MIN(a,b) (a < b ? a : b) +#endif + +#ifndef MAX +# define MAX(a,b) (a > b ? a : b) +#endif + +/**************************************************************************** + * Public Types + ****************************************************************************/ + +/* This structure defines each packed block on the FLASH media */ + +struct nxffs_block_s +{ + uint8_t magic[4]; /* 0-3: Magic number for valid block */ + uint8_t state; /* 4: Block state: See BLOCK_STATE_* */ +}; +#define SIZEOF_NXFFS_BLOCK_HDR 5 + +/* This structure defines each packed NXFFS inode header on the FLASH media */ + +struct nxffs_inode_s +{ + uint8_t magic[4]; /* 0-3: Magic number for valid inode */ + uint8_t state; /* 4: Inode state: See INODE_STATE_* */ + uint8_t namlen; /* 5: Length of the inode name */ + uint8_t noffs[4]; /* 6-9: FLASH offset to the file name */ + uint8_t doffs[4]; /* 10-13: FLASH offset to the first data block */ + uint8_t utc[4]; /* 14-17: Creation time */ + uint8_t crc[4]; /* 18-21: CRC32 */ + uint8_t datlen[4]; /* 22-25: Length of data in bytes */ +}; +#define SIZEOF_NXFFS_INODE_HDR 26 + +/* This structure defines each packed NXFFS data header on the FLASH media */ + +struct nxffs_data_s +{ + uint8_t magic[4]; /* 0-3: Magic number for valid data */ + uint8_t crc[4]; /* 4-7: CRC32 */ + uint8_t datlen[2]; /* 8-9: Length of data in bytes */ +}; +#define SIZEOF_NXFFS_DATA_HDR 10 + +/* This is an in-memory representation of the NXFFS inode as extracted from + * FLASH and with additional state information. + */ + +struct nxffs_entry_s +{ + off_t hoffset; /* FLASH offset to the inode header */ + off_t noffset; /* FLASH offset to the inode name */ + off_t doffset; /* FLASH offset to the first data header */ + FAR char *name; /* inode name */ + uint32_t utc; /* Time stamp */ + uint32_t datlen; /* Length of inode data */ +}; + +/* This structure describes int in-memory representation of the data block */ + +struct nxffs_blkentry_s +{ + off_t hoffset; /* Offset to the block data header */ + uint16_t datlen; /* Length of data following the header */ + uint16_t foffset; /* Offset to start of data */ +}; + +/* This structure describes the state of one open file. This structure + * is protected by the volume semaphore. + */ + +struct nxffs_ofile_s +{ + struct nxffs_ofile_s *flink; /* Supports a singly linked list */ + int16_t crefs; /* Reference count */ + mode_t oflags; /* Open mode */ + struct nxffs_entry_s entry; /* Describes the NXFFS inode entry */ +}; + +/* A file opened for writing require some additional information */ + +struct nxffs_wrfile_s +{ + /* The following fields provide the common open file information. */ + + struct nxffs_ofile_s ofile; + + /* The following fields are required to support the write operation */ + + bool truncate; /* Delete a file of the same name */ + uint16_t datlen; /* Number of bytes written in data block */ + off_t doffset; /* FLASH offset to the current data header */ + uint32_t crc; /* Accumulated data block CRC */ +}; + +/* This structure represents the overall state of on NXFFS instance. */ + +struct nxffs_volume_s +{ + FAR struct mtd_dev_s *mtd; /* Supports FLASH access */ + sem_t exclsem; /* Used to assure thread-safe access */ + sem_t wrsem; /* Enforces single writer restriction */ + struct mtd_geometry_s geo; /* Device geometry */ + uint8_t blkper; /* R/W blocks per erase block */ + uint16_t iooffset; /* Next offset in read/write access (in ioblock) */ + off_t inoffset; /* Offset to the first valid inode header */ + off_t froffset; /* Offset to the first free byte */ + off_t nblocks; /* Number of R/W blocks on volume */ + off_t ioblock; /* Current block number being accessed */ + off_t cblock; /* Starting block number in cache */ + FAR struct nxffs_ofile_s *ofiles; /* A singly-linked list of open files */ + FAR uint8_t *cache; /* On cached erase block for general I/O */ + FAR uint8_t *pack; /* A full erase block to support packing */ +}; + +/* This structure describes the state of the blocks on the NXFFS volume */ + +struct nxffs_blkstats_s +{ + off_t nblocks; /* Total number of FLASH blocks */ + off_t ngood; /* Number of good FLASH blocks found */ + off_t nbad; /* Number of well-formatted FLASH blocks marked as bad */ + off_t nunformat; /* Number of unformatted FLASH blocks */ + off_t ncorrupt; /* Number of blocks with correupted format info */ +}; + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/* The magic number that appears that the beginning of each NXFFS (logical) + * block + */ + +extern const uint8_t g_blockmagic[NXFFS_MAGICSIZE]; + +/* The magic number that appears that the beginning of each NXFFS inode */ + +extern const uint8_t g_inodemagic[NXFFS_MAGICSIZE]; + +/* The magic number that appears that the beginning of each NXFFS inode + * data block. + */ + +extern const uint8_t g_datamagic[NXFFS_MAGICSIZE]; + +/* If CONFIG_NXFSS_PREALLOCATED is defined, then this is the single, pre- + * allocated NXFFS volume instance. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED +extern struct nxffs_volume_s g_volume; +#endif + +/**************************************************************************** + * Public Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * 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. + * + * Defined in nxffs_initialize.c + * + ****************************************************************************/ + +extern int nxffs_limits(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Name: nxffs_rdle16 + * + * Description: + * Get a (possibly unaligned) 16-bit little endian value. + * + * Input Parameters: + * val - A pointer to the first byte of the little endian value. + * + * Returned Values: + * A uint16_t representing the whole 16-bit integer value + * + * Defined in nxffs_util.c + * + ****************************************************************************/ + +extern uint16_t nxffs_rdle16(FAR const uint8_t *val); + +/**************************************************************************** + * Name: nxffs_wrle16 + * + * Description: + * Put a (possibly unaligned) 16-bit little endian value. + * + * Input Parameters: + * dest - A pointer to the first byte to save the little endian value. + * val - The 16-bit value to be saved. + * + * Returned Values: + * None + * + * Defined in nxffs_util.c + * + ****************************************************************************/ + +extern void nxffs_wrle16(uint8_t *dest, uint16_t val); + +/**************************************************************************** + * Name: nxffs_rdle32 + * + * Description: + * Get a (possibly unaligned) 32-bit little endian value. + * + * Input Parameters: + * val - A pointer to the first byte of the little endian value. + * + * Returned Values: + * A uint32_t representing the whole 32-bit integer value + * + * Defined in nxffs_util.c + * + ****************************************************************************/ + +extern uint32_t nxffs_rdle32(FAR const uint8_t *val); + +/**************************************************************************** + * Name: nxffs_wrle32 + * + * Description: + * Put a (possibly unaligned) 32-bit little endian value. + * + * Input Parameters: + * dest - A pointer to the first byte to save the little endian value. + * val - The 32-bit value to be saved. + * + * Returned Value: + * None + * + * Defined in nxffs_util.c + * + ****************************************************************************/ + +extern void nxffs_wrle32(uint8_t *dest, uint32_t val); + +/**************************************************************************** + * Name: nxffs_erased + * + * Description: + * Check if a block of memory is in the erased state. + * + * Input Parameters: + * buffer - Address of the start of the memory to check. + * buflen - The number of bytes to check. + * + * Returned Values: + * The number of erased bytes found at the beginning of the memory region. + * + * Defined in nxffs_util.c + * + ****************************************************************************/ + +extern size_t nxffs_erased(FAR const uint8_t *buffer, size_t buflen); + +/**************************************************************************** + * Name: nxffs_rdcache + * + * Description: + * Read one I/O block into the volume cache memory. + * + * Input Parameters: + * volume - Describes the current volume + * block - The first logical block to read + * + * Returned Value: + * Negated errnos are returned only in the case of MTD reported failures. + * Nothing in the volume data itself will generate errors. + * + * Defined in nxffs_cache.c + * + ****************************************************************************/ + +extern int nxffs_rdcache(FAR struct nxffs_volume_s *volume, off_t block); + +/**************************************************************************** + * Name: nxffs_wrcache + * + * Description: + * Write one or more logical blocks from the volume cache memory. + * + * Input Parameters: + * volume - Describes the current volume + * + * Returned Value: + * Negated errnos are returned only in the case of MTD reported failures. + * + * Defined in nxffs_cache.c + * + ****************************************************************************/ + +extern int nxffs_wrcache(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Name: nxffs_ioseek + * + * Description: + * Seek to a position in FLASH memory. This simply sets up the offsets + * and pointer values. This is a necessary step prior to using + * nxffs_getc(). + * + * Input Parameters: + * volume - Describes the NXFFS volume + * offset - The physical offset in bytes from the beginning of the FLASH + * in bytes. + * + * Defined in nxffs_cache.c + * + ****************************************************************************/ + +extern void nxffs_ioseek(FAR struct nxffs_volume_s *volume, off_t offset); + +/**************************************************************************** + * Name: nxffs_iotell + * + * Description: + * Report the current position. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * + * Returned Value: + * The offset from the beginning of FLASH to the current seek position. + * + * Defined in nxffs_cache.c + * + ****************************************************************************/ + +extern off_t nxffs_iotell(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Name: nxffs_getc + * + * Description: + * Get the next byte from FLASH. This function allows the data in the + * formatted FLASH blocks to be read as a continuous byte stream, skipping + * over bad blocks and block headers as necessary. + * + * Input Parameters: + * volume - Describes the NXFFS volume. The paramters ioblock and iooffset + * in the volume structure determine the behavior of nxffs_getc(). + * reserve - If less than this much space is available at the end of the + * block, then skip to the next block. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno indicating the + * nature of the failure. + * + * Defined in nxffs_cache.c + * + ****************************************************************************/ + +extern int nxffs_getc(FAR struct nxffs_volume_s *volume, uint16_t reserve); + +/**************************************************************************** + * Name: nxffs_freeentry + * + * Description: + * The inode values returned by nxffs_nextentry() include allocated memory + * (specifically, the file name string). This function should be called + * to dispose of that memory when the inode entry is no longer needed. + * + * Note that the nxffs_entry_s containing structure is not freed. The + * caller may call kfree upon return of this function if necessary to + * free the entry container. + * + * Input parameters: + * entry - The entry to be freed. + * + * Returned Value: + * None + * + * Defined in nxffs_inode.c + * + ****************************************************************************/ + +extern void nxffs_freeentry(FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * Name: nxffs_nextentry + * + * Description: + * Search for the next valid inode starting at the provided FLASH offset. + * + * Input Parameters: + * volume - Describes the NXFFS volume. + * offset - The FLASH memory offset to begin searching. + * entry - A pointer to memory provided by the caller in which to return + * the inode description. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno is returned + * that indicates the nature of the failure. + * + * Defined in nxffs_inode.c + * + ****************************************************************************/ + +extern int nxffs_nextentry(FAR struct nxffs_volume_s *volume, off_t offset, + FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * Name: nxffs_findinode + * + * Description: + * Search for an inode with the provided name starting with the first + * valid inode and proceeding to the end FLASH or until the matching + * inode is found. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * name - The name of the inode to find + * entry - The location to return information about the inode. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno is returned + * that indicates the nature of the failure. + * + * Defined in nxffs_inode.c + * + ****************************************************************************/ + +extern int nxffs_findinode(FAR struct nxffs_volume_s *volume, + FAR const char *name, + FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * Name: nxffs_inodeend + * + * Description: + * Return an *approximiate* FLASH offset to end of the inode data. The + * returned value is guaranteed to be be less then or equal to the offset + * of the thing-of-interest in FLASH. Parsing for interesting things + * can begin at that point. + * + * Assumption: The inode header has been verified by the caller and is + * known to contain valid data. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * entry - Describes the inode. + * + * Returned Value: + * A FLASH offset to the (approximate) end of the inode data. No errors + * are detected. + * + * Defined in nxffs_inode.c + * + ****************************************************************************/ + +extern off_t nxffs_inodeend(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * 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. + * + * Defined in nxffs_block.c + * + ****************************************************************************/ + +extern int nxffs_verifyblock(FAR struct nxffs_volume_s *volume, off_t block); + +/**************************************************************************** + * 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. + * + * Defined in nxffs_block.c + * + ****************************************************************************/ + +extern int nxffs_validblock(struct nxffs_volume_s *volume, off_t *block); + +/**************************************************************************** + * Name: nxffs_blockstats + * + * Description: + * Analyze the NXFFS volume. This operation must be performed when the + * volume is first mounted in order to detect if the volume has been + * formatted and contains a usable NXFFS file system. + * + * Input Parameters: + * volume - Describes the current NXFFS volume. + * stats - On return, will hold nformation describing the state of the + * volume. + * + * Returned Value: + * Negated errnos are returned only in the case of MTD reported failures. + * Nothing in the volume data itself will generate errors. + * + * Defined in nxffs_blockstats.c + * + ****************************************************************************/ + +extern int nxffs_blockstats(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_blkstats_s *stats); + +/**************************************************************************** + * Name: nxffs_reformat + * + * Description: + * Erase and reformat the entire volume. Verify each block and mark + * improperly erased blocks as bad. + * + * Input Parameters: + * volume - Describes the NXFFS volume to be reformatted. + * + * Returned Value: + * Zero on success or a negated errno on a failure. Failures will be + * returned n the case of MTD reported failures o. + * Nothing in the volume data itself will generate errors. + * + * Defined in nxffs_reformat.c + * + ****************************************************************************/ + +extern int nxffs_reformat(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Name: nxffs_findofile + * + * Description: + * Search the list of already opened files to see if the inode of this + * name is one of the opened files. + * + * Input Parameters: + * volume - Describes the NXFFS volume. + * name - The name of the inode to check. + * + * Returned Value: + * If an inode of this name is found in the list of opened inodes, then + * a reference to the open file structure is returned. NULL is returned + * otherwise. + * + * Defined in nxffs_open.c + * + ****************************************************************************/ + +extern FAR struct nxffs_ofile_s *nxffs_findofile(FAR struct nxffs_volume_s *volume, + FAR const char *name); + +/**************************************************************************** + * Name: nxffs_findwriter + * + * Description: + * Search the list of already opened files and return the open file + * instance for the write. + * + * Input Parameters: + * volume - Describes the NXFFS volume. + * + * Returned Value: + * If there is an active writer of the volume, its open file instance is + * returned. NULL is returned otherwise. + * + * Defined in nxffs_open.c + * + ****************************************************************************/ + +extern FAR struct nxffs_wrfile_s *nxffs_findwriter(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Name: nxffs_wrinode + * + * Description: + * Write the inode header (only to FLASH. This is done in two contexts: + * + * 1. When an inode is closed, or + * 2. As part of the file system packing logic when an inode is moved. + * + * Note that in either case, the inode name has already been written to + * FLASH. + * + * Input parameters + * volume - Describes the NXFFS volume + * entry - Describes the inode header to write + * + * Returned Value: + * Zero is returned on success; Otherwise, a negated errno value is returned + * indicating the nature of the failure. + * + * Defined in nxffs_open.c + * + ****************************************************************************/ + +extern int nxffs_wrinode(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * Name: nxffs_updateinode + * + * Description: + * The packing logic has moved an inode. Check if any open files are using + * this inode and, if so, move the data in the open file structure as well. + * + * Input parameters + * volume - Describes the NXFFS volume + * entry - Describes the new inode entry + * + * Returned Value: + * Zero is returned on success; Otherwise, a negated errno value is returned + * indicating the nature of the failure. + * + ****************************************************************************/ + +extern int nxffs_updateinode(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry); + +/**************************************************************************** + * Name: nxffs_wrreserve + * + * Description: + * Find a valid location for a file system object of 'size'. A valid + * location will have these properties: + * + * 1. It will lie in the free flash region. + * 2. It will have enough contiguous memory to hold the entire object + * 3. The memory at this location will be fully erased. + * + * This function will only perform the checks of 1) and 2). The + * end-of-filesystem offset, froffset, is update past this memory which, + * in effect, reserves the memory. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * size - The size of the object to be reserved. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno value is + * returned indicating the nature of the failure. Of special interest + * the return error of -ENOSPC which means that the FLASH volume is + * full and should be repacked. + * + * On successful return the following are also valid: + * + * volume->ioblock - Read/write block number of the block containing the + * candidate oject position + * volume->iooffset - The offset in the block to the candidate object + * position. + * volume->froffset - Updated offset to the first free FLASH block after + * the reserved memory. + * + * Defined in nxffs_write.c + * + ****************************************************************************/ + +extern int nxffs_wrreserve(FAR struct nxffs_volume_s *volume, size_t size); + +/**************************************************************************** + * Name: nxffs_wrverify + * + * Description: + * Find a valid location for the object. A valid location will have + * these properties: + * + * 1. It will lie in the free flash region. + * 2. It will have enough contiguous memory to hold the entire header + * (excluding the file name which may lie in the next block). + * 3. The memory at this location will be fully erased. + * + * This function will only perform the check 3). On entry it assumes the + * following settings (left by nxffs_wrreserve()): + * + * volume->ioblock - Read/write block number of the block containing the + * candidate oject position + * volume->iooffset - The offset in the block to the candidate object + * position. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * size - The size of the object to be verifed. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno value is + * returned indicating the nature of the failure. Of special interest + * the return error of -ENOSPC which means that the FLASH volume is + * full and should be repacked. + * + * On successful return the following are also valid: + * + * volume->ioblock - Read/write block number of the block containing the + * verified object position + * volume->iooffset - The offset in the block to the verified object + * position. + * volume->froffset - Updated offset to the first free FLASH block. + * + * Defined in nxffs_write.c + * + ****************************************************************************/ + +extern int nxffs_wrverify(FAR struct nxffs_volume_s *volume, size_t size); + +/**************************************************************************** + * Name: nxffs_wrblkhdr + * + * Description: + * Write the block header information. This is done (1) whenever the end- + * block is encountered and (2) also when the file is closed in order to + * flush the final block of data to FLASH. + * + * Input Parameters: + * volume - Describes the state of the NXFFS volume + * wrfile - Describes the state of the open file + * + * Returned Value: + * Zero is returned on success; Otherwise, a negated errno value is + * returned to indicate the nature of the failure. + * + * Defined in nxffs_write.c + * + ****************************************************************************/ + +extern int nxffs_wrblkhdr(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile); + +/**************************************************************************** + * Name: nxffs_nextblock + * + * Description: + * Search for the next valid data block starting at the provided + * FLASH offset. + * + * Input Parameters: + * volume - Describes the NXFFS volume. + * datlen - A memory location to return the data block length. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno is returned + * that indicates the nature of the failure. + * + * Defined in nxffs_read.c + * + ****************************************************************************/ + +extern int nxffs_nextblock(FAR struct nxffs_volume_s *volume, off_t offset, + FAR struct nxffs_blkentry_s *blkentry); + +/**************************************************************************** + * Name: nxffs_rdblkhdr + * + * Description: + * Read and verify the data block header at the specified offset. + * + * Input Parameters: + * volume - Describes the current volume. + * offset - The byte offset from the beginning of FLASH where the data block + * header is expected. + * datlen - A memory location to return the data block length. + * + * Returned Value: + * Zero on success. Otherwise, a negated errno value is returned + * indicating the nature of the failure. + * + * Defined in nxffs_read.c + * + ****************************************************************************/ + +extern int nxffs_rdblkhdr(FAR struct nxffs_volume_s *volume, off_t offset, + FAR uint16_t *datlen); + +/**************************************************************************** + * Name: nxffs_rminode + * + * Description: + * Remove an inode from FLASH. This is the internal implementation of + * the file system unlinke operation. + * + * Input Parameters: + * volume - Describes the NXFFS volume. + * name - the name of the inode to be deleted. + * + * Returned Value: + * Zero is returned if the inode is successfully deleted. Otherwise, a + * negated errno value is returned indicating the nature of the failure. + * + ****************************************************************************/ + +extern int nxffs_rminode(FAR struct nxffs_volume_s *volume, FAR const char *name); + +/**************************************************************************** + * Name: nxffs_pack + * + * Description: + * Pack and re-write the filesystem in order to free up memory at the end + * of FLASH. + * + * Input Parameters: + * volume - The volume to be packed. + * + * Returned Values: + * Zero on success; Otherwise, a negated errno value is returned to + * indicate the nature of the failure. + * + ****************************************************************************/ + +extern int nxffs_pack(FAR struct nxffs_volume_s *volume); + +/**************************************************************************** + * Standard mountpoint operation methods + * + * Description: + * See include/nuttx/fs/fs.h + * + * - nxffs_open() and nxffs_close() are defined in nxffs_open.c + * - nxffs_read() is defined in nxffs_read.c + * - nxffs_write() is defined in nxffs_write.c + * - nxffs_ioctl() is defined in nxffs_ioctl.c + * - nxffs_opendir(), nxffs_readdir(), and nxffs_rewindir() are defined in + * nxffs_dirent.c + * - nxffs_bind() and nxffs_unbind() are defined in nxffs_initialize.c + * - nxffs_stat() and nxffs_statfs() are defined in nxffs_stat.c + * - nxffs_unlink() is defined nxffs_unlink.c + * + ****************************************************************************/ + +struct file; /* Forward references */ +struct inode; +struct fs_dirent_s; +struct statfs; +struct stat; + +extern int nxffs_open(FAR struct file *filep, FAR const char *relpath, + int oflags, mode_t mode); +extern int nxffs_close(FAR struct file *filep); +extern ssize_t nxffs_read(FAR struct file *filep, FAR char *buffer, + size_t buflen); +extern ssize_t nxffs_write(FAR struct file *filep, FAR const char *buffer, + size_t buflen); +extern int nxffs_ioctl(FAR struct file *filep, int cmd, unsigned long arg); +extern int nxffs_opendir(FAR struct inode *mountpt, FAR const char *relpath, + FAR struct fs_dirent_s *dir); +extern int nxffs_readdir(FAR struct inode *mountpt, FAR struct fs_dirent_s *dir); +extern int nxffs_rewinddir(FAR struct inode *mountpt, FAR struct fs_dirent_s *dir); +extern int nxffs_bind(FAR struct inode *blkdriver, FAR const void *data, + FAR void **handle); +extern int nxffs_unbind(FAR void *handle, FAR struct inode **blkdriver); +extern int nxffs_statfs(FAR struct inode *mountpt, FAR struct statfs *buf); +extern int nxffs_stat(FAR struct inode *mountpt, FAR const char *relpath, + FAR struct stat *buf); +extern int nxffs_unlink(FAR struct inode *mountpt, FAR const char *relpath); + +#endif /* __FS_NXFFS_NXFFS_H */ + + |