Unable to mount ext4 partition in Dolphin. Error says it busy.

[rahulprabhakar]

During Live Boot session of 14.04.1 after copying data and rechecking contents on my backup partition (ext4) i did unmount partition from Dolphin file manager. There were no files open.

Now if i Boot the system again in the same Live Boot session and try to mount the same partition it shows the following error

An error occurred while accessing 'Recovery', the system responded: The requested operation has failed: Error mounting /dev/sda4 at /media/kubuntu/Recovery: Command-line `mount -t "ext4" -o "uhelper=udisks2,nodev,nosuid" "/dev/sda4" "/media/kubuntu/Recovery"' c mount: /dev/sda4 already mounted or /media/kubuntu/Recovery busy

What can i do to resolve this issue.

Output of dumpe2fs is pasted below with -h option to only display the superblock information and not any of the block group descriptor detail information.

kubuntu@kubuntu:~$ sudo dumpe2fs -h /dev/sda4
dumpe2fs 1.42.9 (4-Feb-2014)
Filesystem volume name: Recovery
Last mounted on: /media/root/Recovery
Filesystem UUID: ff662111-21b9-4cd6-8107-bcb61f0f4257
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 3964928
Block count: 15859712
Reserved block count: 792985
Free blocks: 2166123
Free inodes: 3789095
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 1020
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8192
Inode blocks per group: 512
Flex block group size: 16
Filesystem created: Sat Mar 5 17:28:28 2016
Last mount time: Sun Mar 6 11:24:11 2016
Last write time: Sun Mar 6 12:26:29 2016
Mount count: 9
Maximum mount count: -1
Last checked: Sat Mar 5 17:28:52 2016
Check interval: 0 (<none>)
Lifetime writes: 53 GB
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: d5ed119f-0f78-4106-b434-8bd5b5328d99
Journal backup: inode blocks
Journal features: (none)
Journal size: 128M
Journal length: 32768
Journal sequence: 0x0000046c
Journal start: 0

kubuntu@kubuntu:~$

[rahulprabhakar]

Resolved this issue By installing GParted in Live Session and executing Check Partition. Gparted showed following command in execution log

e2fsck -f -y -v -C 0 /dev/sda4

If executing this command from Terminal command would be - sudo e2fsck -f -y -v -C 0 /dev/sda4 where sda4 is desired device