I'm trying to convert the hard drive partitions to ext4. I archived the files in /opt, formatted this partition in ext4 as in instructions, connect the modules from the modules-1.9.2.7-rtn-r5066-MIPS32r2.tgz, corrected fstab, restored the files from the archive back, and reboot the router... ext4 partition is not mounted and is not displayed in the mount, df -h, and ext4 support in /proc/filesystems appeared. In what may be the reason that the section is not mounted? (
Router Asus RT-N16 c iOS 1.9.2.7-rtn-r5362. Some logs:
	Code:
	[admin@WL-BCAEC5C484F0 root]$ cat /etc/fstab 
#device Mountpoint FStype Options Dump Pass#
/dev/sda1 none swap sw 0 0
/dev/sda2 /opt ext4 rw,noatime,barrier0 1 1
/dev/sda3 /tmp/mnt/disca_3 ext3 rw,noatime 1 1
[admin@WL-BCAEC5C484F0 root]$
 
	Code:
	[admin@WL-BCAEC5C484F0 root]$ mount
rootfs on / type rootfs (rw)
/dev/root on / type squashfs (ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devfs on /dev type tmpfs (rw,noatime)
devpts on /dev/pts type devpts (rw)
tmpfs on /tmp type tmpfs (rw,noatime)
usbfs on /proc/bus/usb type usbfs (rw)
nfsd on /proc/fs/nfsd type nfsd (rw)
/dev/discs/disca/part3 on /tmp/mnt/disca_3 type ext3 (rw,noatime,errors=continue,data=ordered)
[admin@WL-BCAEC5C484F0 root]$
 
	Code:
	[admin@WL-BCAEC5C484F0 root]$ df -h
Filesystem                Size      Used Available Use% Mounted on
rootfs                    4.6M      4.6M         0 100% /
/dev/root                 4.6M      4.6M         0 100% /
devfs                   100.0K      4.0K     96.0K   4% /dev
tmpfs                    61.9M    616.0K     61.3M   1% /tmp
/dev/discs/disca/part3
                          1.8T      1.7T         0 100% /tmp/mnt/disca_3
[admin@WL-BCAEC5C484F0 root]$
 
	Code:
	[admin@WL-BCAEC5C484F0 root]$ cat /proc/filesystems 
nodev	sysfs
nodev	rootfs
nodev	bdev
nodev	proc
nodev	sockfs
nodev	pipefs
nodev	anon_inodefs
nodev	tmpfs
nodev	inotifyfs
nodev	devpts
	ext3
	squashfs
nodev	ramfs
	vfat
nodev	usbfs
	ntfs
nodev	rpc_pipefs
nodev	nfsd
	ext4
[admin@WL-BCAEC5C484F0 root]$
 
	Code:
	[admin@WL-BCAEC5C484F0 root]$ cat /tmp/syslog.log 
...
Jan  1 04:00:03 kernel: usbcore: registered new interface driver usbfs
Jan  1 04:00:03 kernel: usbcore: registered new interface driver hub
Jan  1 04:00:03 kernel: usbcore: registered new device driver usb
Jan  1 04:00:03 kernel: ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
Jan  1 04:00:03 kernel: USB20H mdio control register : 0x8000000c
Jan  1 04:00:03 kernel: ehci_hcd 0000:00:04.1: EHCI Host Controller
Jan  1 04:00:03 kernel: ehci_hcd 0000:00:04.1: new USB bus registered, assigned bus number 1
Jan  1 04:00:03 kernel: ehci_hcd 0000:00:04.1: irq 5, io mem 0x18004000
Jan  1 04:00:03 kernel: ehci_hcd 0000:00:04.1: USB 0.0 started, EHCI 1.00
Jan  1 04:00:03 kernel: usb usb1: configuration #1 chosen from 1 choice
Jan  1 04:00:03 kernel: hub 1-0:1.0: USB hub found
Jan  1 04:00:03 kernel: hub 1-0:1.0: 2 ports detected
Jan  1 04:00:03 kernel: usbcore: registered new interface driver usblp
Jan  1 04:00:03 kernel: usb 1-2: new high speed USB device using ehci_hcd and address 2
Jan  1 04:00:04 kernel: SCSI subsystem initialized
Jan  1 04:00:04 kernel: usb 1-2: configuration #1 chosen from 1 choice
Jan  1 04:00:04 kernel: Initializing USB Mass Storage driver...
Jan  1 04:00:04 kernel: scsi0 : SCSI emulation for USB Mass Storage devices
Jan  1 04:00:04 kernel: usbcore: registered new interface driver usb-storage
Jan  1 04:00:04 kernel: USB Mass Storage support registered.
Jan  1 04:00:04 kernel: NTFS driver 2.1.30 [Flags: R/O MODULE].
Jan  1 04:00:04 kernel: Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
Jan  1 04:00:04 portmap[311]: user 'rpc' not found, reverting to default uid
Jan  1 04:00:05 statd[313]: Version 1.1.6 Starting
Jan  1 04:00:05 statd[313]: statd running as root. chown /var/lib/nfs/sm to choose different user
Jan  1 04:00:06 kernel: scsi 0:0:0:0: Direct-Access     Seagate  FA GoFlex Desk   0155 PQ: 0 ANSI: 4
Jan  1 04:00:06 kernel: sd 0:0:0:0: [sda] 3907029167 512-byte hardware sectors (2000399 MB)
Jan  1 04:00:06 kernel: sd 0:0:0:0: [sda] Write Protect is off
Jan  1 04:00:06 kernel: sd 0:0:0:0: [sda] Assuming drive cache: write through
Jan  1 04:00:06 kernel:  sda: sda1 sda2 sda3
Jan  1 04:00:06 kernel: sd 0:0:0:0: [sda] Attached SCSI disk
...
Jan  1 04:00:23 kernel: Adding 506008k swap on /dev/sda1.  Priority:-1 extents:1 across:506008k
Jan  1 04:00:24 kernel: EXT4-fs (sda2): Unrecognized mount option "barrier0" or missing value
Jan  1 04:00:24 kernel: Unhandled kernel unaligned access[#1]:
Jan  1 04:00:24 kernel: Cpu 0
Jan  1 04:00:24 kernel: $ 0   : 00000000 00000062 800a5d2c 00000001
Jan  1 04:00:24 kernel: $ 4   : 810e6c40 00000000 ffffffff 80286250
Jan  1 04:00:24 kernel: $ 8   : 00000000 80316064 00003fff 756c6176
Jan  1 04:00:24 kernel: $12   : 00000000 000f7181 00000000 00000067
Jan  1 04:00:24 kernel: $16   : 810e6b78 873b6c00 800745fc ffffffea
Jan  1 04:00:24 kernel: $20   : 86d36740 810e6c40 800c0000 00000000
Jan  1 04:00:24 kernel: $24   : 00000001 8013e20c                  
Jan  1 04:00:24 kernel: $28   : 86cf8000 86cf9bd8 00000001 c0257a48
Jan  1 04:00:24 kernel: Hi    : 00000000
Jan  1 04:00:24 kernel: Lo    : 4c023000
Jan  1 04:00:24 kernel: epc   : 800a5d30 bd_release+0x4/0x38     Tainted: P       
Jan  1 04:00:24 kernel: ra    : c0257a48 ext4_group_desc_csum_verify+0x6a4/0x2ed8 [ext4]
Jan  1 04:00:24 kernel: Status: 1100bc03    KERNEL EXL IE 
Jan  1 04:00:24 kernel: Cause : 00000010
Jan  1 04:00:24 kernel: BadVA : 00000031
Jan  1 04:00:24 kernel: PrId  : 00019740
Jan  1 04:00:24 kernel: Modules linked in: ext4 crc16 jbd2 nfsd exportfs lockd sunrpc ntfs usb_storage sd_mod scsi_mod usblp ehci_hcd usbcore nf_nat_ftp nf_conntrack_ftp wl(P) et(P) igs(P) emf(P)
Jan  1 04:00:24 kernel: Process mount (pid: 397, threadinfo=86cf8000, task=86cce000)
Jan  1 04:00:24 kernel: Stack : 00000000 86cf9b50 00000000 00000000 00000000 00000003 00000000 00000000
Jan  1 04:00:24 kernel:         00000000 00000000 00000000 86e42000 00000000 00000000 00000000 00000000
Jan  1 04:00:24 kernel:         00000001 00000000 00000000 00000000 86cf9cb0 00000002 8735b500 802edc60
Jan  1 04:00:24 kernel:         00008000 86e42000 86e3c000 00490000 7ff13a78 80114c64 800794b4 80079c18
Jan  1 04:00:24 kernel:         878af188 8033c9c0 86cf9c7c c02755a0 873b6c00 800bc084 873b6c40 00000200
Jan  1 04:00:24 kernel:         ...
Jan  1 04:00:24 kernel: Call Trace:
Jan  1 04:00:24 kernel: [<800a5d30>] bd_release+0x4/0x38
Jan  1 04:00:24 kernel: [<c0257a48>] ext4_group_desc_csum_verify+0x6a4/0x2ed8 [ext4]
Jan  1 04:00:24 kernel: Code: 03e00008  ac83ffa0  8c83003c <8c620030> 2442ffff  14400003  ac620030  8c82003c  ac40002c 
Feb  8 19:27:35 USB storage: ext3 fs at /dev/discs/disca/part3 mounted to /tmp/mnt/disca_3
Feb  8 19:27:38 dropbear[391]: Exit before auth (user 'admin', 0 fails): Timeout before auth
Feb  8 19:27:43 dropbear[399]: Child connection from 192.168.1.115:37688
Feb  8 19:27:46 dropbear[399]: Password auth succeeded for 'admin' from 192.168.1.115:37688
[admin@WL-BCAEC5C484F0 root]$
 Does not mounted. Maybe have more some logs what I should to see? 
Maybe in this case the reason is the same as described wpte, here?