Sudden failure on certain DFS shares

We use CIFS on our CentOS 6 systems to access numerous DFS shares hosted on a Windows 2008 cluster. Until yesterday this had proved to be very reliable.

Late yesterday afternoon we discovered that on two shares we could no longer create a directory or filename containing more than ten characters.

The length of the parent directory structure is 83 characters and we want to create a new sub directory with 50 characters which is well within the 255 limit permitted on Windows servers.

The relevant mount entry is:

//xxxxxx.com/PRDFS/OTRS_Index_CUST\134Index /opt/otrs/var/article cifs  rw,relatime,sec=ntlm,cache=loose,unc=\\xxxxxx \OTRS_CUST_Index,username=xxx,domain=xxx,uid=48,forceuid,gid=48,forcegid,addr=10.135.16.55,file_mode=0775,dir_mode=0775,nounix,prepath=\Index,rsize=61440,wsize=65536,actimeo=1 0 0

The exact error message is:

fs/cifs/dir.c: Full path: \Index\2016\08\26\check_permissions_5714_623122911_1472217688_224561 inode = 0x(null)
fs/cifs/inode.c: Getting info on \Index\2016\08\26\check_permissions_5714_623122911_1472217688_224561
fs/cifs/transport.c: For smb_command 50
fs/cifs/transport.c: Sending smb: smb_len=210
fs/cifs/connect.c: RFC1002 header 0x23
fs/cifs/connect.c: invalid transact2 word count
fs/cifs/transport.c: cifs_sync_mid_result: cmd=50 mid=36157 state=4
Status code returned 0xc0000034 NT_STATUS_OBJECT_NAME_NOT_FOUND
fs/cifs/netmisc.c: Mapping smb error code 2 to POSIX err -2
fs/cifs/cifssmb.c: Send error in QPathInfo = -2

All the parent directories exist.

Any advice really would be most welcome.

TIA

Shaun

This issue was eventually traced to both Windows DFS servers losing access to the shared drive simultaneously.

The issue was resolved by rebooting the Windows servers and executing chkdsk.