Help! My phone becomes unbootable suddenly

It is Samsung Galaxy Note 2, unrooted.
I factory reset my phone to stock ROM about a week ago. Suddenly it became unbootable today. I didn't do anything risky. If my memory serves, I simply updated an app one day before this incident.

It always stuck at the Samsung Galaxy Note 2 logo screen.
I can boot to recovery mode and download mode.

The following errors displayed when I booted to recovery mode:

Android system recovery < 3e >
KOT49H.N7100ZSUFNL1

E:failed to mount /efs (No such file or directory)
E:failed to mount /system ((No such file or directory))

# MANUAL MODE #
--Appling Multi-CSC
E:failed to mount /system (No such file or directory)
can't mount '/system' (No such file or directory)
E:failed to mount /cache (No such file or directory)
can't mount '/cache' (No such file or directory)
E:failed to mount /cache (No such file or directory)
E:can't mount /cache/recovery/last_recovery
E:failed to mount /data (No such file or directory)
E:can't mount /data/log/recovery_log.txt
E:failed to mount /system (No such file or directory)
E:failed to mount /cache (No such file or directory)
E:can't mount /cache/recovery/log
E:can't open /cache/recovery/log
E:failed to mount cache (No such file or recovery)
E:Can't mount /cache/recovery/last_log
E:can't open /cache/recovery/last_log
E:failed to mount /cache (No such file or recovery)
E:can't mount /cache/recovery/last_install
E:Can't open /cache/recovery/last_install
E:failed to mount /cache (No such file or recovery)

I tried to wipe cache partition. It didn't help.

1. How could I backup data in this case?
   I just need to get back my photos.

2. How could I fix and restore my phone?

Please help. Thanks a lot.

— modified on Dec 3, 2016, 6:35:43 AM

Could anyone help?