remarkable-linux/include/linux/nfs_mount.h
Suresh Jayaraman 5eebde2322 nfs: introduce mount option '-olocal_lock' to make locks local
NFS clients since 2.6.12 support flock locks by emulating fcntl byte-range
locks. Due to this, some windows applications which seem to use both flock
(share mode lock mapped as flock by Samba) and fcntl locks sequentially on
the same file, can't lock as they falsely assume the file is already locked.
The problem was reported on a setup with windows clients accessing excel files
on a Samba exported share which is originally a NFS mount from a NetApp filer.

Older NFS clients (< 2.6.12) did not see this problem as flock locks were
considered local. To support legacy flock behavior, this patch adds a mount
option "-olocal_lock=" which can take the following values:

   'none'  		- Neither flock locks nor POSIX locks are local
   'flock' 		- flock locks are local
   'posix' 		- fcntl/POSIX locks are local
   'all'		- Both flock locks and POSIX locks are local

Testing:

   - This patch was tested by using -olocal_lock option with different values
     and the NLM calls were noted from the network packet captured.

     'none'  - NLM calls were seen during both flock() and fcntl(), flock lock
   	       was granted, fcntl was denied
     'flock' - no NLM calls for flock(), NLM call was seen for fcntl(),
   	       granted
     'posix' - NLM call was seen for flock() - granted, no NLM call for fcntl()
     'all'   - no NLM calls were seen during both flock() and fcntl()

   - No bugs were seen during NFSv4 locking/unlocking in general and NFSv4
     reboot recovery.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-09-23 08:55:58 -04:00

78 lines
2.3 KiB
C

#ifndef _LINUX_NFS_MOUNT_H
#define _LINUX_NFS_MOUNT_H
/*
* linux/include/linux/nfs_mount.h
*
* Copyright (C) 1992 Rick Sladkey
*
* structure passed from user-space to kernel-space during an nfs mount
*/
#include <linux/in.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
/*
* WARNING! Do not delete or change the order of these fields. If
* a new field is required then add it to the end. The version field
* tracks which fields are present. This will ensure some measure of
* mount-to-kernel version compatibility. Some of these aren't used yet
* but here they are anyway.
*/
#define NFS_MOUNT_VERSION 6
#define NFS_MAX_CONTEXT_LEN 256
struct nfs_mount_data {
int version; /* 1 */
int fd; /* 1 */
struct nfs2_fh old_root; /* 1 */
int flags; /* 1 */
int rsize; /* 1 */
int wsize; /* 1 */
int timeo; /* 1 */
int retrans; /* 1 */
int acregmin; /* 1 */
int acregmax; /* 1 */
int acdirmin; /* 1 */
int acdirmax; /* 1 */
struct sockaddr_in addr; /* 1 */
char hostname[NFS_MAXNAMLEN + 1]; /* 1 */
int namlen; /* 2 */
unsigned int bsize; /* 3 */
struct nfs3_fh root; /* 4 */
int pseudoflavor; /* 5 */
char context[NFS_MAX_CONTEXT_LEN + 1]; /* 6 */
};
/* bits in the flags field visible to user space */
#define NFS_MOUNT_SOFT 0x0001 /* 1 */
#define NFS_MOUNT_INTR 0x0002 /* 1 */ /* now unused, but ABI */
#define NFS_MOUNT_SECURE 0x0004 /* 1 */
#define NFS_MOUNT_POSIX 0x0008 /* 1 */
#define NFS_MOUNT_NOCTO 0x0010 /* 1 */
#define NFS_MOUNT_NOAC 0x0020 /* 1 */
#define NFS_MOUNT_TCP 0x0040 /* 2 */
#define NFS_MOUNT_VER3 0x0080 /* 3 */
#define NFS_MOUNT_KERBEROS 0x0100 /* 3 */
#define NFS_MOUNT_NONLM 0x0200 /* 3 */
#define NFS_MOUNT_BROKEN_SUID 0x0400 /* 4 */
#define NFS_MOUNT_NOACL 0x0800 /* 4 */
#define NFS_MOUNT_STRICTLOCK 0x1000 /* reserved for NFSv4 */
#define NFS_MOUNT_SECFLAVOUR 0x2000 /* 5 */
#define NFS_MOUNT_NORDIRPLUS 0x4000 /* 5 */
#define NFS_MOUNT_UNSHARED 0x8000 /* 5 */
#define NFS_MOUNT_FLAGMASK 0xFFFF
/* The following are for internal use only */
#define NFS_MOUNT_LOOKUP_CACHE_NONEG 0x10000
#define NFS_MOUNT_LOOKUP_CACHE_NONE 0x20000
#define NFS_MOUNT_NORESVPORT 0x40000
#define NFS_MOUNT_LEGACY_INTERFACE 0x80000
#define NFS_MOUNT_LOCAL_FLOCK 0x100000
#define NFS_MOUNT_LOCAL_FCNTL 0x200000
#endif