Need information on a filesystem error:

Question

I have console access to an embedded linux device. This device has flash memory part of which is partitioned as a FAT filesystem.

Its running linux-2.6.31.

However I am seeing these errors on the console these days and the FAT file system becomes read only.

111109:154925 FAT: Filesystem error (dev loop0)
111109:154925 fat_get_cluster: invalid cluster chain (i_pos 0)
111109:154925 FAT: Filesystem error (dev loop0)
111109:154925 fat_get_cluster: invalid cluster chain (i_pos 0)

I cannot understand why this happened? What is the root cause? And what is the fix? I would appreciate answers that can point me how to investigate the possible root cause of this issue on the device.

Answer 1

The most likely cause of this is the FAT file system has become corrupt through power loss or some other issue that prevented a file operation to be finished successfully.

Same as pulling a usb drive out of a PC without removing safely.

It can be repaired by using

/sbin/fsck.vfat -a /dev/<fat device>