I have compile source code as module. my command in Makefile is

gcc -D__KERNEL__ -DMODULE -DEXPORT_SYMTAB -DMODVERSIONS -DCONFIG_IP_VS_DEBUG -g -O2 -Wall -Wstrict-prototypes -I/usr/src/linux/include -include /usr/src/linux/include/linux/modversions.h -c -o ip_ftp.o ip_ftp.c

when i insmod -f ip_ftp.o some error is :
ip_ftp.o: unresolved symbol nr_free_pages
ip_ftp.o: unresolved symbol page_cache_size
ip_ftp.o: unresolved symbol ip_mc_join_group

To solve this problem i have add that line in ksyms.c. Then i compile ksyms.c with
gcc -D__KERNEL__ -DMODULE -DEXPORT_SYMTAB -DMODVERSIONS -DCONFIG_IP_VS_DEBUG -g -O2 -Wall -Wstrict-prototypes -I/usr/src/linux/include -include /usr/src/linux/include/linux/modversions.h -c -o ip_ksyms.o ksyms.c

Why when i try compile ip_ftp again, there is still unresolve symbol.
Thanks about the help

It seems like there is another module that this particular module is dependant on. Have you tried using 'modprobe' instead of 'insmod' to load the module? 'modprobe' will make an attempt at finding dependancies for the module you are loading, whereas 'insmod' will not.