[Samsung Galaxy SL i9003] Napstar:
Are you still able to boot into recovery or download mode.

If yes, then you still have some chance to recover your device, yourself.

As a last resort consider doing this.

If you could boot into download, then install any custom Kernel, so as to have root priviledge

and a good bash environment in recovery.

Now boot into recovery and check filesystem type of each partition, if it is correct.

And then try formatting them by yourself.

Here is my partition table information. (for Cyanogenmod9 alpha6 ROM)

root@android:/ # df
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 248564 32 248532 0% /dev
df: /mnt/.lfs: Function not implemented
/dev/block/stl11 31484 4148 27336 13% /cache
tmpfs 248564 0 248564 0% /mnt/asec
tmpfs 248564 0 248564 0% /mnt/obb
/dev/block/stl9 326552 270852 55700 83% /system
/dev/block/mmcblk0p3 1935128 257784 1677344 13% /data
/dev/block/stl10 74072 4148 69924 6% /dbdata
/dev/block/stl3 6064 5155 909 85% /efs
/dev/block/vold/179:17
3870240 3794432 75808 98% /mnt/emmc
/dev/block/vold/179:1
1595136 1340832 254304 84% /mnt/sdcard
/dev/block/vold/179:1
1595136 1340832 254304 84% /mnt/secure/asec
/dev/block/dm-0 6236 4424 1812 71% /mnt/asec/com.teamviewer.teamviewer.market.mobile-2
/dev/block/dm-1 6236 4508 1728 72% /mnt/asec/com.natenai.glowhockey-2
1|root@android:/ # mount
rootfs on / type rootfs (ro,relatime)
tmpfs on /dev type tmpfs (rw,nosuid,relatime,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
/sys/kernel/debug on /sys/kernel/debug type debugfs (rw,relatime)
/dev/block/stl6 on /mnt/.lfs type j4fs (rw,relatime)
none on /acct type cgroup (rw,relatime,cpuacct)
/dev/block/stl11 on /cache type ext4 (rw,nodev,noatime,nodiratime,commit=20,barrier=1,nobh,data=ordered,noauto_da_alloc)
tmpfs on /mnt/asec type tmpfs (rw,relatime,mode=755,gid=1000)
tmpfs on /mnt/obb type tmpfs (rw,relatime,mode=755,gid=1000)
none on /dev/cpuctl type cgroup (rw,relatime,cpu)
/dev/block/stl9 on /system type ext4 (ro,noatime,commit=20,barrier=1,nobh,data=ordered,noauto_da_alloc)
/dev/block/mmcblk0p3 on /data type ext4 (rw,noatime,commit=20,barrier=1,nobh,data=ordered,noauto_da_alloc)
/dev/block/stl10 on /dbdata type ext4 (rw,noatime,commit=20,barrier=0,nobh,nodelalloc,data=ordered,noauto_da_alloc)
/dev/block/stl3 on /efs type rfs (rw,nosuid,nodev,relatime,vfat,llw,check=no,gid/uid/rwx,iocharset=cp437)
debugfs on /debug type debugfs (rw,relatime)
/dev/block/vold/179:17 on /mnt/emmc type vfat (rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
/dev/block/vold/179:1 on /mnt/sdcard type vfat (rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
/dev/block/vold/179:1 on /mnt/secure/asec type vfat (rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
tmpfs on /mnt/sdcard/.android_secure type tmpfs (ro,relatime,size=0k,mode=000)
/dev/block/dm-0 on /mnt/asec/com.teamviewer.teamviewer.market.mobile-2 type vfat (ro,dirsync,nosuid,nodev,relatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
/dev/block/dm-1 on /mnt/asec/com.natenai.glowhockey-2 type vfat (ro,dirsync,nosuid,nodev,relatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
root@android:/ #