diff options
Diffstat (limited to 'nuttx/fs/fat/fs_fat32util.c')
| -rw-r--r-- | nuttx/fs/fat/fs_fat32util.c | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/nuttx/fs/fat/fs_fat32util.c b/nuttx/fs/fat/fs_fat32util.c index c6680b6f0..f38cc3741 100644 --- a/nuttx/fs/fat/fs_fat32util.c +++ b/nuttx/fs/fat/fs_fat32util.c @@ -44,6 +44,7 @@ ****************************************************************************/ #include <nuttx/config.h> + #include <sys/types.h> #include <stdlib.h> #include <string.h> @@ -2303,7 +2304,8 @@ int fat_ffcacheinvalidate(struct fat_mountpt_s *fs, struct fat_file_s *ff) /* Then discard the current cache contents */ - ff->ff_bflags &= ~FFBUFF_VALID; + ff->ff_bflags &= ~FFBUFF_VALID; + ff->ff_cachesector = 0; } return OK; } @@ -2461,3 +2463,47 @@ int fat_nfreeclusters(struct fat_mountpt_s *fs, size_t *pfreeclusters) return OK; } +/**************************************************************************** + * Name: fat_nfreeclusters + * + * Desciption: + * Given the file position, set the correct current sector to access. + * + ****************************************************************************/ + +int fat_currentsector(struct fat_mountpt_s *fs, struct fat_file_s *ff, + off_t position) +{ + int sectoroffset; + + if (position <= ff->ff_size ) + { + /* sectoroffset is the sector number offset into the current cluster */ + + sectoroffset = SEC_NSECTORS(fs, position) & CLUS_NDXMASK(fs); + + /* The current cluster is the the first sector of the cluster plus + * the sector offset + */ + + ff->ff_currentsector = fat_cluster2sector(fs, ff->ff_currentcluster) + + sectoroffset; + + /* The remainder is the number of sectors left in the cluster to be + * read/written + */ + + ff->ff_sectorsincluster = fs->fs_fatsecperclus - sectoroffset; + + fvdbg("position=%d currentsector=%d sectorsincluster=%d\n", + position, ff->ff_currentsector, ff->ff_sectorsincluster); + + return OK; + } + + /* The position does not lie within the file */ + + return -ENOSPC; +} + + |