What is the meaning of the following eCryptFS errors?

Issue

• The following errors in the "/var/log/messages":

$ grep 'ecryptfs_write_end' var/log/messages  | tail -n 5
Mar  6 08:42:14 server.example.com kernel: ecryptfs_write_end: Error encrypting page (upper index [0x000000000000c565])
Mar  6 08:42:14 server.example.com kernel: ecryptfs_write_end: Error encrypting page (upper index [0x000000000000c565])
Mar  6 08:42:14 server.example.com kernel: ecryptfs_write_end: Error encrypting page (upper index [0x000000000000c565])
Mar  6 08:42:14 server.example.com kernel: ecryptfs_write_end: Error encrypting page (upper index [0x000000000000c565])
Mar  6 08:42:14 server.example.com kernel: ecryptfs_write_end: Error encrypting page (upper index [0x000000000000c565])

are caused by writing to an ecryptfs filesystem with a full backing device

• The following errors in the "/var/log/messages":

$ grep 'ecryptfs_encrypt_page' var/log/messages | tail -n 5
Mar  6 08:42:14 server.example.com kernel: ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-28]
Mar  6 08:42:14 server.example.com kernel: ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-28]
Mar  6 08:42:14 server.example.com kernel: ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-28]
Mar  6 08:42:14 server.example.com kernel: ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-28]
Mar  6 08:42:14 server.example.com kernel: ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-28]

are caused by attempting to open a file which was written to the unencrypted backing device, via the crypted mount point