diff options
Diffstat (limited to 'nuttx/fs/fat/fs_fat32util.c')
| -rw-r--r-- | nuttx/fs/fat/fs_fat32util.c | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/nuttx/fs/fat/fs_fat32util.c b/nuttx/fs/fat/fs_fat32util.c index 637e4d1a3..c70c4cb1e 100644 --- a/nuttx/fs/fat/fs_fat32util.c +++ b/nuttx/fs/fat/fs_fat32util.c @@ -858,7 +858,7 @@ ssize_t fat_cluster2sector(struct fat_mountpt_s *fs, uint32 cluster ) /**************************************************************************** * Name: fat_getcluster * - * Desciption: Get the cluster start sector into the FAT. + * Desciption: Get the next cluster start from the FAT. * * Return: <0: error, 0:cluster unassigned, >=0: start sector of cluster * @@ -880,7 +880,7 @@ ssize_t fat_getcluster(struct fat_mountpt_s *fs, uint32 clusterno) { size_t fatsector; unsigned int fatoffset; - unsigned int startsector; + unsigned int cluster; unsigned int fatindex; /* FAT12 is more complex because it has 12-bits (1.5 bytes) @@ -895,13 +895,14 @@ ssize_t fat_getcluster(struct fat_mountpt_s *fs, uint32 clusterno) if (fat_fscacheread(fs, fatsector) < 0) { /* Read error */ + break; } /* Get the first, LS byte of the cluster from the FAT */ - fatindex = fatoffset & SEC_NDXMASK(fs); - startsector = fs->fs_buffer[fatindex]; + fatindex = fatoffset & SEC_NDXMASK(fs); + cluster = fs->fs_buffer[fatindex]; /* With FAT12, the second byte of the cluster number may lie in * a different sector than the first byte. @@ -916,6 +917,7 @@ ssize_t fat_getcluster(struct fat_mountpt_s *fs, uint32 clusterno) if (fat_fscacheread(fs, fatsector) < 0) { /* Read error */ + break; } } @@ -925,21 +927,23 @@ ssize_t fat_getcluster(struct fat_mountpt_s *fs, uint32 clusterno) * on the fact that the byte stream is little-endian. */ - startsector |= (unsigned int)fs->fs_buffer[fatindex] << 8; + cluster |= (unsigned int)fs->fs_buffer[fatindex] << 8; /* Now, pick out the correct 12 bit cluster start sector value */ if ((clusterno & 1) != 0) { /* Odd.. take the MS 12-bits */ - startsector >>= 4; + + cluster >>= 4; } else { /* Even.. take the LS 12-bits */ - startsector &= 0x0fff; + + cluster &= 0x0fff; } - return startsector; + return cluster; } case FSTYPE_FAT16 : @@ -967,7 +971,7 @@ ssize_t fat_getcluster(struct fat_mountpt_s *fs, uint32 clusterno) /* Read error */ break; } - return FAT_GETFAT16(fs->fs_buffer, fatindex) & 0x0fffffff; + return FAT_GETFAT32(fs->fs_buffer, fatindex) & 0x0fffffff; } default: break; @@ -2198,20 +2202,21 @@ int fat_ffcacheflush(struct fat_mountpt_s *fs, struct fat_file_s *ff) * contents of ff_buffer. */ - if (ff->ff_bflags && (FFBUFF_DIRTY|FFBUFF_VALID) == (FFBUFF_DIRTY|FFBUFF_VALID)) - { + if (ff->ff_cachesector && + ff->ff_bflags && (FFBUFF_DIRTY|FFBUFF_VALID) == (FFBUFF_DIRTY|FFBUFF_VALID)) + { /* Write the dirty sector */ - ret = fat_hwwrite(fs, ff->ff_buffer, ff->ff_currentsector, 1); + ret = fat_hwwrite(fs, ff->ff_buffer, ff->ff_cachesector, 1); if (ret < 0) - { + { return ret; - } + } - /* No longer dirty */ + /* No longer dirty, but still valid */ ff->ff_bflags &= ~FFBUFF_DIRTY; - } + } return OK; } @@ -2228,12 +2233,12 @@ int fat_ffcacheread(struct fat_mountpt_s *fs, struct fat_file_s *ff, size_t sect { int ret; - /* ff->ff_currentsector holds the current sector that is buffered in + /* ff->ff_cachesector holds the current sector that is buffered in * ff->ff_buffer. If the requested sector is the same as this sector, then * we do nothing. Otherwise, we will have to read the new sector. */ - if (ff->ff_currentsector != sector || (ff->ff_bflags & FFBUFF_VALID) == 0) + if (ff->ff_cachesector != sector || (ff->ff_bflags & FFBUFF_VALID) == 0) { /* We will need to read the new sector. First, flush the cached * sector if it is dirty. @@ -2255,7 +2260,7 @@ int fat_ffcacheread(struct fat_mountpt_s *fs, struct fat_file_s *ff, size_t sect /* Update the cached sector number */ - ff->ff_currentsector = sector; + ff->ff_cachesector = sector; ff->ff_bflags |= FFBUFF_VALID; } return OK; |