diff options
Diffstat (limited to 'nuttx/fs')
| -rw-r--r-- | nuttx/fs/fat/fs_fat32.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/nuttx/fs/fat/fs_fat32.c b/nuttx/fs/fat/fs_fat32.c index 4dfda324f..8a7f6e29a 100644 --- a/nuttx/fs/fat/fs_fat32.c +++ b/nuttx/fs/fat/fs_fat32.c @@ -708,14 +708,6 @@ static ssize_t fat_write(FAR struct file *filep, const char *buffer, while (buflen > 0) { - /* Check if there is unwritten data in the file buffer */ - - ret = fat_ffcacheflush(fs, ff); - if (ret < 0) - { - goto errout_with_semaphore; - } - /* Check if the user has provided a buffer large enough to * hold one or more complete sectors. */ @@ -737,7 +729,8 @@ static ssize_t fat_write(FAR struct file *filep, const char *buffer, } /* We are not sure of the state of the file buffer so - * the safest thing to do is just invalidate it + * the safest thing to do is write back any dirty, cached sector + * and invalidate the current cache content. */ (void)fat_ffcacheinvalidate(fs, ff); @@ -770,6 +763,10 @@ static ssize_t fat_write(FAR struct file *filep, const char *buffer, if (filep->f_pos < ff->ff_size || sectorindex != 0) { + /* Read the current sector into memory (perhaps first flushing + * the old, dirty sector to disk). + */ + ret = fat_ffcacheread(fs, ff, ff->ff_currentsector); if (ret < 0) { @@ -778,9 +775,15 @@ static ssize_t fat_write(FAR struct file *filep, const char *buffer, } else { - /* But in this rare case, we do have to mark the unused cached - * buffer as the current buffer. - */ + /* Flush unwritten data in the sector cache. */ + + ret = fat_ffcacheflush(fs, ff); + if (ret < 0) + { + goto errout_with_semaphore; + } + + /* Now mark the clean cache buffer as the current sector. */ ff->ff_cachesector = ff->ff_currentsector; } |