diff options
Diffstat (limited to 'nuttx/fs/nxffs/nxffs_open.c')
| -rw-r--r-- | nuttx/fs/nxffs/nxffs_open.c | 1263 |
1 files changed, 1263 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_open.c b/nuttx/fs/nxffs/nxffs_open.c new file mode 100644 index 000000000..339e25edc --- /dev/null +++ b/nuttx/fs/nxffs/nxffs_open.c @@ -0,0 +1,1263 @@ +/**************************************************************************** + * fs/nxffs/nxffs_open.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 <fcntl.h> +#include <time.h> +#include <crc32.h> +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/fs/fs.h> +#include <nuttx/mtd.h> + +#include "nxffs.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/* Since we are limited to a single file opened for writing, it makes sense + * to pre-allocate the write state structure. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED +static struct nxffs_wrfile_s g_wrfile; +#endif + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nxffs_hdrpos + * + * Description: + * Find a valid location for the inode header. 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 checks of 1) and 2). + * + * Input Parameters: + * volume - Describes the NXFFS volume + * wrfile - Contains the current guess for the header position. On + * successful return, this field will hold the selected header + * position. + * + * 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: + * + * wrfile->ofile.entry.hoffset - FLASH offset to candidate header position + * volume->ioblock - Read/write block number of the block containing the + * header position + * volume->iooffset - The offset in the block to the candidate header + * position. + * volume->froffset - Updated offset to the first free FLASH block. + * + ****************************************************************************/ + +static inline int nxffs_hdrpos(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile) +{ + int ret; + + /* Reserve memory for the object */ + + ret = nxffs_wrreserve(volume, SIZEOF_NXFFS_INODE_HDR); + if (ret == OK) + { + /* Save the offset to the FLASH region reserved for the inode header */ + + wrfile->ofile.entry.hoffset = nxffs_iotell(volume); + } + return ret; +} + +/**************************************************************************** + * Name: nxffs_nampos + * + * Description: + * Find a valid location for the inode name. 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 name + * 3. The memory at this location will be fully erased. + * + * This function will only perform the checks of 1) and 2). + * + * Input Parameters: + * volume - Describes the NXFFS volume + * wrfile - Contains the current guess for the name position. On + * successful return, this field will hold the selected name + * position. + * namlen - The length of the name. + * + * 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: + * + * wrfile->ofile.entry.noffset - FLASH offset to candidate name position + * volume->ioblock - Read/write block number of the block containing the + * name position + * volume->iooffset - The offset in the block to the candidate name + * position. + * volume->froffset - Updated offset to the first free FLASH block. + * + ****************************************************************************/ + +static inline int nxffs_nampos(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile, + int namlen) +{ + int ret; + + /* Reserve memory for the object */ + + ret = nxffs_wrreserve(volume, namlen); + if (ret == OK) + { + /* Save the offset to the FLASH region reserved for the inode name */ + + wrfile->ofile.entry.noffset = nxffs_iotell(volume); + } + return ret; +} + +/**************************************************************************** + * Name: nxffs_hdrerased + * + * Description: + * Find a valid location for the inode header. 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: + * + * volume->ioblock - Read/write block number of the block containing the + * header position + * volume->iooffset - The offset in the block to the candidate header + * position. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * wrfile - Contains the current guess for the header position. On + * successful return, this field will hold the selected header + * position. + * + * 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: + * + * wrfile->ofile.entry.hoffset - FLASH offset to candidate header position + * volume->ioblock - Read/write block number of the block containing the + * header position + * volume->iooffset - The offset in the block to the candidate header + * position. + * volume->froffset - Updated offset to the first free FLASH block. + * + ****************************************************************************/ + +static inline int nxffs_hdrerased(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile) +{ + int ret; + + /* Find a valid location to save the inode header */ + + ret = nxffs_wrverify(volume, SIZEOF_NXFFS_INODE_HDR); + if (ret == OK) + { + /* This is where we will put the header */ + + wrfile->ofile.entry.hoffset = nxffs_iotell(volume); + } + return ret; +} + +/**************************************************************************** + * Name: nxffs_namerased + * + * Description: + * Find a valid location for the inode name. 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 name + * (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: + * + * volume->ioblock - Read/write block number of the block containing the + * name position + * volume->iooffset - The offset in the block to the candidate name + * position. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * wrfile - Contains the current guess for the name position. On + * successful return, this field will hold the selected name + * position. + * + * 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: + * + * wrfile->ofile.entry.noffset - FLASH offset to candidate name position + * volume->ioblock - Read/write block number of the block containing the + * name position + * volume->iooffset - The offset in the block to the candidate name + * position. + * volume->froffset - Updated offset to the first free FLASH block. + * + ****************************************************************************/ + +static inline int nxffs_namerased(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile, + int namlen) +{ + int ret; + + /* Find a valid location to save the inode name */ + + ret = nxffs_wrverify(volume, namlen); + if (ret == OK) + { + /* This is where we will put the name */ + + wrfile->ofile.entry.noffset = nxffs_iotell(volume); + } + return ret; +} + +/**************************************************************************** + * Name: nxffs_wrname + * + * Description: + * Write the inode name to cache at the position verified by + * nxffs_namerased(). + * + * On entry it assumes: + * + * entry->noffset - FLASH offset to final name position + * volume->ioblock - Read/write block number of the block containing the + * name position + * volume->iooffset - The offset in the block to the candidate name + * position. + * + * Input Parameters: + * volume - Describes the NXFFS volume + * entry - Describes the entry to be written. + * + * Returned Value: + * Zero is returned on success. Otherwise, a negated errno value is + * returned indicating the nature of the failure. + * + ****************************************************************************/ + +static inline int nxffs_wrname(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry, + int namlen) +{ + int ret; + + /* Seek to the inode name position and assure that it is in the volume + * cache. + */ + + nxffs_ioseek(volume, entry->noffset); + ret = nxffs_rdcache(volume, volume->ioblock); + if (ret < 0) + { + fdbg("Failed to read inode name block %d: %d\n", + volume->ioblock, -ret); + return ret; + } + + /* Copy the inode name to the volume cache and write the inode name block */ + + memcpy(&volume->cache[volume->iooffset], entry->name, namlen); + ret = nxffs_wrcache(volume); + if (ret < 0) + { + fdbg("Failed to write inode header block %d: %d\n", + volume->ioblock, -ret); + } + + return ret; +} + +/**************************************************************************** + * Name: nxffs_wropen + * + * Description: + * Handle opening for writing. Only a single writer is permitted and only + * file creation is supported. + * + ****************************************************************************/ + +static inline int nxffs_wropen(FAR struct nxffs_volume_s *volume, + FAR const char *name, mode_t oflags, + FAR struct nxffs_ofile_s **ppofile) +{ + FAR struct nxffs_wrfile_s *wrfile; + FAR struct nxffs_entry_s entry; + bool packed; + bool truncate = false; + int namlen; + int ret; + + /* Limitation: Only a single writer is permitted. Writing may involve + * extension of the file system in FLASH. Since files are contiguous + * in FLASH, only a single file may be extending the FLASH region. + */ + + ret = sem_wait(&volume->wrsem); + if (ret != OK) + { + fdbg("sem_wait failed: %d\n", ret); + ret = -errno; + goto errout; + } + + /* Get exclusive access to the volume. Note that the volume exclsem + * protects the open file list. Note that exclsem is ALWAYS taken + * after wrsem to avoid deadlocks. + */ + + ret = sem_wait(&volume->exclsem); + if (ret != OK) + { + fdbg("sem_wait failed: %d\n", ret); + ret = -errno; + goto errout_with_wrsem; + } + + /* Check if the file exists */ + + ret = nxffs_findinode(volume, name, &entry); + if (ret == OK) + { + FAR struct nxffs_ofile_s *ofile; + + /* It exists. Is the file already open for reading? */ + + ofile = nxffs_findofile(volume, name); + if (ofile) + { + /* The file is already open. + * Limitation: Files cannot be open both for reading and writing. + */ + + fdbg("File is open for reading\n"); + ret = -ENOSYS; + goto errout_with_exclsem; + } + + /* It would be an error if we are asked to create the file + * exclusively. + */ + + else if ((oflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) + { + fdbg("File exists, can't create O_EXCL\n"); + ret = -EEXIST; + goto errout_with_exclsem; + } + + /* Were we asked to truncate the file? NOTE: Don't truncate the + * file if we were not also asked to created it. See below... + * we will not re-create the file unless O_CREAT is also specified. + */ + + else if ((oflags & (O_CREAT|O_TRUNC)) == (O_CREAT|O_TRUNC)) + { + /* Just schedule the removal the file and fall through to re-create it. + * Note that the old file of the same name will not actually be removed + * until the new file is successfully written. + */ + + truncate = true; + } + + /* The file exists and we were not asked to truncate (and recreate) it. + * Limitation: Cannot write to existing files. + */ + + else + { + fdbg("File %s exists and we were not asked to truncate it\n"); + ret = -ENOSYS; + goto errout_with_exclsem; + } + } + + /* Okay, the file is not open and does not exists (maybe because we deleted + * it). Now, make sure that we were asked to created it. + */ + + if ((oflags & O_CREAT) == 0) + { + fdbg("Not asked to create the file\n"); + ret = -ENOENT; + goto errout_with_exclsem; + } + + /* Make sure that the length of the file name will fit in a uint8_t */ + + namlen = strlen(name); + if (namlen > CONFIG_NXFFS_MAXNAMLEN) + { + fdbg("Name is too long: %d\n", namlen); + ret = -EINVAL; + goto errout_with_exclsem; + } + + /* Yes.. Create a new structure that will describe the state of this open + * file. NOTE that a special variant of the open file structure is used + * that includes additional information to support the write operation. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED + wrfile = &g_wrfile; + memset(wrfile, 0, sizeof(struct nxffs_wrfile_s)); +#else + wrfile = (FAR struct nxffs_wrfile_s *)kzalloc(sizeof(struct nxffs_wrfile_s)); + if (!wrfile) + { + ret = -ENOMEM; + goto errout_with_exclsem; + } +#endif + + /* Initialize the open file state structure */ + + wrfile->ofile.crefs = 1; + wrfile->ofile.oflags = oflags; + wrfile->ofile.entry.utc = time(NULL); + wrfile->truncate = truncate; + + /* Save a copy of the inode name. */ + + wrfile->ofile.entry.name = strdup(name); + if (!wrfile->ofile.entry.name) + { + ret = -ENOMEM; + goto errout_with_ofile; + } + + /* Allocate FLASH memory for the file and set up for the write. + * + * Loop until the inode header is configured or until a failure occurs. + * Note that nothing is written to FLASH. The inode header is not + * written until the file is closed. + */ + + packed = false; + for (;;) + { + /* File a valid location to position the inode header. Start with the + * first byte in the free FLASH region. + */ + + ret = nxffs_hdrpos(volume, wrfile); + if (ret == OK) + { + /* Find a region of memory in the block that is fully erased */ + + ret = nxffs_hdrerased(volume, wrfile); + if (ret == OK) + { + /* Valid memory for the inode header was found. Break out of + * the loop. + */ + + break; + } + } + + /* If no valid memory is found searching to the end of the volume, + * then -ENOSPC will be returned. Other errors are not handled. + */ + + if (ret != -ENOSPC || packed) + { + fdbg("Failed to find inode header memory: %d\n", -ret); + goto errout_with_name; + } + + /* -ENOSPC is a special case.. It means that the volume is full. + * Try to pack the volume in order to free up some space. + */ + + ret = nxffs_pack(volume); + if (ret < 0) + { + fdbg("Failed to pack the volume: %d\n", -ret); + goto errout_with_name; + } + + /* After packing the volume, froffset will be updated to point to the + * new free flash region. Try again. + */ + + packed = true; + } + + /* Loop until the inode name is configured or until a failure occurs. + * Note that nothing is written to FLASH. + */ + + for (;;) + { + /* File a valid location to position the inode name. Start with the + * first byte in the free FLASH region. + */ + + ret = nxffs_nampos(volume, wrfile, namlen); + if (ret == OK) + { + /* Find a region of memory in the block that is fully erased */ + + ret = nxffs_namerased(volume, wrfile, namlen); + if (ret == OK) + { + /* Valid memory for the inode header was found. Write the + * inode name to this location. + */ + + ret = nxffs_wrname(volume, &wrfile->ofile.entry, namlen); + if (ret < 0) + { + fdbg("Failed to write the inode name: %d\n", -ret); + goto errout_with_name; + } + + /* Then just break out of the loop reporting success. Note + * that the alllocated inode name string is retained; it + * will be needed later to calculate the inode CRC. + */ + + break; + } + } + + /* If no valid memory is found searching to the end of the volume, + * then -ENOSPC will be returned. Other errors are not handled. + */ + + if (ret != -ENOSPC || packed) + { + fdbg("Failed to find inode name memory: %d\n", -ret); + goto errout_with_name; + } + + /* -ENOSPC is a special case.. It means that the volume is full. + * Try to pack the volume in order to free up some space. + */ + + ret = nxffs_pack(volume); + if (ret < 0) + { + fdbg("Failed to pack the volume: %d\n", -ret); + goto errout_with_name; + } + + /* After packing the volume, froffset will be updated to point to the + * new free flash region. Try again. + */ + + packed = true; + } + + /* Add the open file structure to the head of the list of open files */ + + wrfile->ofile.flink = volume->ofiles; + volume->ofiles = &wrfile->ofile; + + /* Indicate that the volume is open for writing and return the open file + * instance. Releasing exclsem allows other readers while the write is + * in progress. But wrsem is still held for this open file, preventing + * any further writers until this inode is closed.s + */ + + *ppofile = &wrfile->ofile; + sem_post(&volume->exclsem); + return OK; + +errout_with_name: + kfree(wrfile->ofile.entry.name); +errout_with_ofile: +#ifndef CONFIG_NXFSS_PREALLOCATED + kfree(wrfile); +#endif + +errout_with_exclsem: + sem_post(&volume->exclsem); +errout_with_wrsem: + sem_post(&volume->wrsem); +errout: + return ret; +} + +/**************************************************************************** + * Name: nxffs_rdopen + * + * Description: + * Open an existing file for reading. + * + ****************************************************************************/ + +static inline int nxffs_rdopen(FAR struct nxffs_volume_s *volume, + FAR const char *name, + FAR struct nxffs_ofile_s **ppofile) +{ + FAR struct nxffs_ofile_s *ofile; + int ret; + + /* Get exclusive access to the volume. Note that the volume exclsem + * protects the open file list. + */ + + ret = sem_wait(&volume->exclsem); + if (ret != OK) + { + fdbg("sem_wait failed: %d\n", ret); + ret = -errno; + goto errout; + } + + /* Check if the file has already been opened (for reading) */ + + ofile = nxffs_findofile(volume, name); + if (ofile) + { + /* The file is already open. + * Limitation: Files cannot be open both for reading and writing. + */ + + if ((ofile->oflags & O_WROK) != 0) + { + fdbg("File is open for writing\n"); + ret = -ENOSYS; + goto errout_with_exclsem; + } + + /* Just increment the reference count on the ofile */ + + ofile->crefs++; + fdbg("crefs: %d\n", ofile->crefs); + } + + /* The file has not yet been opened. + * Limitation: The file must exist. We do not support creation of files + * read-only. + */ + + else + { + /* Not already open.. create a new open structure */ + + ofile = (FAR struct nxffs_ofile_s *)kzalloc(sizeof(struct nxffs_ofile_s)); + if (!ofile) + { + fdbg("ofile allocation failed\n"); + ret = -ENOMEM; + goto errout_with_exclsem; + } + + /* Initialize the open file state structure */ + + ofile->crefs = 1; + ofile->oflags = O_RDOK; + + /* Find the file on this volume associated with this file name */ + + ret = nxffs_findinode(volume, name, &ofile->entry); + if (ret != OK) + { + fvdbg("Inode '%s' not found: %d\n", name, -ret); + goto errout_with_ofile; + } + + /* Add the open file structure to the head of the list of open files */ + + ofile->flink = volume->ofiles; + volume->ofiles = ofile; + } + + /* Return the open file state structure */ + + *ppofile = ofile; + sem_post(&volume->exclsem); + return OK; + +errout_with_ofile: + kfree(ofile); +errout_with_exclsem: + sem_post(&volume->exclsem); +errout: + return ret; +} + +/**************************************************************************** + * Name: nxffs_remofile + * + * Description: + * Remove an entry from the open file list. + * + ****************************************************************************/ + +static inline void nxffs_remofile(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_ofile_s *ofile) +{ + FAR struct nxffs_ofile_s *prev; + FAR struct nxffs_ofile_s *curr; + + /* Find the open file structure to be removed */ + + for (prev = NULL, curr = volume->ofiles; + curr && curr != ofile; + prev = curr, curr = curr->flink); + + /* Was it found? */ + + if (curr) + { + /* Yes.. at the head of the list? */ + + if (prev) + { + prev->flink = ofile->flink; + } + else + { + volume->ofiles = ofile->flink; + } + } + else + { + fdbg("ERROR: Open inode %p not found\n", ofile); + } +} + +/**************************************************************************** + * Name: nxffs_freeofile + * + * Description: + * Free resources held by an open file. + * + ****************************************************************************/ + +static inline void nxffs_freeofile(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_ofile_s *ofile) +{ + /* Release the open file entry */ + + nxffs_freeentry(&ofile->entry); + + /* Then free the open file container (unless this the pre-alloated + * write-only open file container) + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED + if ((FAR struct nxffs_wrfile_s*)ofile != &g_wrfile) +#endif + { + kfree(ofile); + } +} + +/**************************************************************************** + * Name: nxffs_wrclose + * + * Description: + * Perform special operations when a file is closed: + * 1. Write the file block header + * 2. Remove any file with the same name that was discovered when the + * file was open for writing, and finally, + * 3. Write the new file inode. + * + * Input parameters + * volume - Describes the NXFFS volume + * wrfile - Describes the state of the open file + * + ****************************************************************************/ + +static inline int nxffs_wrclose(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_wrfile_s *wrfile) +{ + int ret; + + /* Is there an unfinalized write data? */ + + if (wrfile->datlen > 0) + { + /* Yes.. Write the final file block header */ + + ret = nxffs_wrblkhdr(volume, wrfile); + if (ret < 0) + { + fdbg("Failed to write the final block of the file: %d\n", -ret); + goto errout; + } + } + + /* Truncation is implemented by writing the new file, then deleting the + * older version of the file. Note that we removed the entry from the + * open file list earlier in the close sequence; this will prevent the + * open file check from failing when we remove the old version of the + * file. + */ + + if (wrfile->truncate && wrfile->ofile.entry.name) + { + fvdbg("Removing old file: %s\n", wrfile->ofile.entry.name); + + ret = nxffs_rminode(volume, wrfile->ofile.entry.name); + if (ret < 0) + { + fdbg("nxffs_rminode failed: %d\n", -ret); + goto errout; + } + } + + /* Write the inode header to FLASH */ + + ret = nxffs_wrinode(volume, &wrfile->ofile.entry); + + /* The volume is now available for other writers */ + +errout: + sem_post(&volume->wrsem); + return ret; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * 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: + * 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. + * + ****************************************************************************/ + +FAR struct nxffs_ofile_s *nxffs_findofile(FAR struct nxffs_volume_s *volume, + FAR const char *name) +{ + FAR struct nxffs_ofile_s *ofile; + + /* Check every open file. Note that the volume exclsem protects the + * list of open files. + */ + + for (ofile = volume->ofiles; ofile; ofile = ofile->flink) + { + /* Check for a name match */ + + if (strcmp(name, ofile->entry.name) == 0) + { + return ofile; + } + } + + return NULL; +} + +/**************************************************************************** + * 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. + * + ****************************************************************************/ + +FAR struct nxffs_wrfile_s *nxffs_findwriter(FAR struct nxffs_volume_s *volume) +{ + /* We can tell if the write is in-use because it will have an allocated + * name attached. + */ + +#ifdef CONFIG_NXFSS_PREALLOCATED + return g_wrfile.ofile.entry.name != NULL ? &g_wrfile : NULL; +#else +# error "Missing implementation" +#endif +} + +/**************************************************************************** + * Name: nxffs_open + * + * Description: + * This is the standard mountpoint open method. + * + ****************************************************************************/ + +int nxffs_open(FAR struct file *filep, FAR const char *relpath, + int oflags, mode_t mode) +{ + FAR struct nxffs_volume_s *volume; + FAR struct nxffs_ofile_s *ofile = NULL; + int ret; + + fvdbg("Open '%s'\n", relpath); + + /* Sanity checks */ + + DEBUGASSERT(filep->f_priv == NULL && filep->f_inode != NULL); + + /* Get the mountpoint private data from the NuttX inode reference in the + * file structure + */ + + volume = (FAR struct nxffs_volume_s*)filep->f_inode->i_private; + DEBUGASSERT(volume != NULL); + +#ifdef CONFIG_FILE_MODE +# warning "Missing check for privileges based on inode->i_mode" +#endif + + /* Limitation: A file must be opened for reading or writing, but not both. + * There is no general for extending the size of of a file. Extending the + * file size of possible if the file to be extended is the last in the + * sequence on FLASH, but since that case is not the general case, no file + * extension is supported. + */ + + switch (oflags & (O_WROK|O_RDOK)) + { + case 0: + default: + fdbg("One of O_WRONLY/O_RDONLY must be provided\n"); + return -EINVAL; + + case O_WROK: + ret = nxffs_wropen(volume, relpath, oflags, &ofile); + break; + + case O_RDOK: + ret = nxffs_rdopen(volume, relpath, &ofile); + break; + + case O_WROK|O_RDOK: + fdbg("O_RDWR is not supported\n"); + return -ENOSYS; + } + + /* Save the reference to the open-specific state in filep->f_priv */ + + if (ret == OK) + { + filep->f_priv = ofile; + } + return ret; +} + +/**************************************************************************** + * Name: nxffs_close + * + * Description: + * This is the standard mountpoint close method. + * + ****************************************************************************/ + +int nxffs_close(FAR struct file *filep) +{ + FAR struct nxffs_volume_s *volume; + FAR struct nxffs_ofile_s *ofile; + int ret = -ENOSYS; + + fvdbg("Closing\n"); + + /* Sanity checks */ + + DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL); + + /* Recover the open file state from the struct file instance */ + + ofile = (FAR struct nxffs_ofile_s *)filep->f_priv; + + /* Recover the volume state from the open file */ + + volume = (FAR struct nxffs_volume_s *)filep->f_inode->i_private; + DEBUGASSERT(volume != NULL); + + /* Get exclusive access to the volume. Note that the volume exclsem + * protects the open file list. + */ + + ret = sem_wait(&volume->exclsem); + if (ret != OK) + { + ret = -errno; + fdbg("sem_wait failed: %d\n", ret); + goto errout; + } + + /* Decrement the reference count on the open file */ + + ret = OK; + if (ofile->crefs == 1) + { + /* Decrementing the reference count would take it zero. + * + * Remove the entry from the open file list. We do this early + * to avoid some chick-and-egg problems with file truncation. + */ + + nxffs_remofile(volume, ofile); + + /* Handle special finalization of the write operation. */ + + if ((ofile->oflags & O_WROK) != 0) + { + ret = nxffs_wrclose(volume, (FAR struct nxffs_wrfile_s *)ofile); + } + + /* Release all resouces held by the open file */ + + nxffs_freeofile(volume, ofile); + } + else + { + /* Just decrement the reference count */ + + ofile->crefs--; + } + + filep->f_priv = NULL; + + sem_post(&volume->exclsem); +errout: + return ret; +} + +/**************************************************************************** + * 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. + * + ****************************************************************************/ + +int nxffs_wrinode(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry) +{ + FAR struct nxffs_inode_s *inode; + uint32_t crc; + int namlen; + int ret; + + /* Seek to the inode header position and assure that it is in the volume + * cache. + */ + + nxffs_ioseek(volume, entry->hoffset); + ret = nxffs_rdcache(volume, volume->ioblock); + if (ret < 0) + { + fdbg("Failed to read inode header block %d: %d\n", + volume->ioblock, -ret); + goto errout; + } + + /* Get the length of the inode name */ + + namlen = strlen(entry->name); + DEBUGASSERT(namlen < CONFIG_NXFFS_MAXNAMLEN); /* This was verified earlier */ + + /* Initialize the inode header */ + + inode = (FAR struct nxffs_inode_s *)&volume->cache[volume->iooffset]; + memcpy(inode->magic, g_inodemagic, NXFFS_MAGICSIZE); + + inode->state = CONFIG_NXFFS_ERASEDSTATE; + inode->namlen = namlen; + + nxffs_wrle32(inode->noffs, entry->noffset); + nxffs_wrle32(inode->doffs, entry->doffset); + nxffs_wrle32(inode->utc, entry->utc); + nxffs_wrle32(inode->crc, 0); + nxffs_wrle32(inode->datlen, entry->datlen); + + /* Calculate the CRC */ + + crc = crc32((FAR const uint8_t *)inode, SIZEOF_NXFFS_INODE_HDR); + crc = crc32part((FAR const uint8_t *)entry->name, namlen, crc); + + /* Finish the inode header */ + + inode->state = INODE_STATE_FILE; + nxffs_wrle32(inode->crc, crc); + + /* Write the block with the inode header */ + + ret = nxffs_wrcache(volume); + if (ret < 0) + { + fdbg("Failed to write inode header block %d: %d\n", + volume->ioblock, -ret); + } + + /* The volume is now available for other writers */ + +errout: + sem_post(&volume->wrsem); + return ret; +} + +/**************************************************************************** + * 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. + * + ****************************************************************************/ + +int nxffs_updateinode(FAR struct nxffs_volume_s *volume, + FAR struct nxffs_entry_s *entry) +{ + FAR struct nxffs_ofile_s *ofile; + + /* Find the open inode structure matching this name */ + + ofile = nxffs_findofile(volume, entry->name); + if (ofile) + { + /* Yes.. the file is open. Update the FLASH offsets to inode headers */ + + ofile->entry.hoffset = entry->hoffset; + ofile->entry.noffset = entry->noffset; + ofile->entry.doffset = entry->doffset; + } + return OK; +} + |