Unmount all fat partitions, executes dosfsck, then remount all fat partitions.
repair_vfat - no arguments
Sample output:
fsck.fat 3.0.28 (2015-05-16)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
Performing changes.
/dev/mmcblk0p1: 4 files, 6633/132264 clusters
fsck.fat 3.0.28 (2015-05-16)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
Performing changes.
/dev/mmcblk0p2: 1 files, 1/1048730 clusters
fsck.fat 3.0.28 (2015-05-16)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
FATs differ but appear to be intact. Using first FAT.
Performing changes.
/dev/mmcblk0p5: 29 files, 3222/132264 clusters
fsck.fat 3.0.28 (2015-05-16)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
Performing changes.
/dev/mmcblk0p6: 7 files, 11/1096290 clusters
fsck.fat 3.0.28 (2015-05-16)
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.
Performing changes.
/dev/mmcblk0p7: 5 files, 2198/132264 clusters