Return Code of the File Functions

On the FatFs API, most of file functions return common result code as enum type FRESULT. When a function succeeded, it returns zero, otherwise returns non-zero value that indicates type of error.

FR_OK (0)
The function succeeded.
FR_DISK_ERR
An unrecoverable error occured in the lower layer, disk_read(), disk_write() or disk_ioctl() function.
FR_INT_ERR
Assertion failed. An insanity is detected in the internal process. One of the following possibilities are suspected.
FR_NOT_READY
The disk drive cannot work due to incorrect medium removal or disk_initialize() function failed.
FR_NO_FILE
Could not find the file.
FR_NO_PATH
Could not find the path.
FR_INVALID_NAME
The given string is invalid as the path name.
FR_DENIED
The required access was denied due to one of the following reasons:
FR_EXIST
Any file or directory that has the same name is already existing.
FR_INVALID_OBJECT
The file/directory object is invalid or a null pointer is given.
FR_WRITE_PROTECTED
Any write mode action against the write-protected media.
FR_INVALID_DRIVE
Invalid drive number is specified in the path name. (Related option: _VOLUMES)
FR_NOT_ENABLED
Work area for the logical drive has not been registered by f_mount() function.
FR_NO_FILESYSTEM
There is no valid FAT volume on the drive.
FR_MKFS_ABORTED
The f_mkfs() function aborted before start in format due to a reason as follows:
FR_TIMEOUT
The function canceled due to a timeout of thread-safe control. (Related option: _TIMEOUT)
FR_LOCKED
The file access is rejected by file sharing control. (Related option: _FS_LOCK)
FR_NOT_ENOUGH_CORE
Not enough memory for the operation. There is one of the following reasons:
FR_TOO_MANY_OPEN_FILES
Number of open files has been reached maximum value and no more file can be opened. (Related option: _FS_LOCK)
FR_INVALID_PARAMETER
The given parameter is invalid or there is any inconsistent.