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nuttx/fs/nxffs/nxffs.h
patacongo 284fb22fee Fix another NXFFS write-when-flash-is-full problem 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4075 42af7a65-404d-4744-a932-0658087f49c3
2011-10-31 20:23:17 +00:00

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/****************************************************************************
* 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/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.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 */
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