diff options
| author | Suresh Jayaraman <sjayaraman@suse.de> | 2010-09-23 08:55:58 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-09-23 08:55:58 -0400 |
| commit | 5eebde23223aeb0ad2d9e3be6590ff8bbfab0fc2 (patch) | |
| tree | 7cfabe0191855550292b0a0c9b317315dffb2a50 /include/linux/nfs_mount.h | |
| parent | 63185942c5f138c62de16b4cbc7eee494a58fea8 (diff) | |
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>
Diffstat (limited to 'include/linux/nfs_mount.h')
| -rw-r--r-- | include/linux/nfs_mount.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h index 5d59ae861aa..576bddd72e0 100644 --- a/include/linux/nfs_mount.h +++ b/include/linux/nfs_mount.h @@ -71,4 +71,7 @@ struct nfs_mount_data { #define NFS_MOUNT_NORESVPORT 0x40000 #define NFS_MOUNT_LEGACY_INTERFACE 0x80000 +#define NFS_MOUNT_LOCAL_FLOCK 0x100000 +#define NFS_MOUNT_LOCAL_FCNTL 0x200000 + #endif |