linux_dsm_epyc7002/include/linux/lockd
Wendy Cheng 4373ea84c8 lockd: unlock lockd locks associated with a given server ip
For high-availability NFS service, we generally need to be able to drop
file locks held on the exported filesystem before moving clients to a
new server.  Currently the only way to do that is by shutting down lockd
entirely, which is often undesireable (for example, if you want to
continue exporting other filesystems).

This patch allows the administrator to release all locks held by clients
accessing the client through a given server ip address, by echoing that
address to a new file, /proc/fs/nfsd/unlock_ip, as in:

shell> echo 10.1.1.2 > /proc/fs/nfsd/unlock_ip

The expected sequence of events can be:
1. Tear down the IP address
2. Unexport the path
3. Write IP to /proc/fs/nfsd/unlock_ip to unlock files
4. Signal peer to begin take-over.

For now we only support IPv4 addresses and NFSv2/v3 (NFSv4 locks are not
affected).

Also, if unmounting the filesystem is required, we assume at step 3 that
clients using the given server ip are the only clients holding locks on
the given filesystem; otherwise, an additional patch is required to
allow revoking all locks held by lockd on a given filesystem.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger  <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

 fs/lockd/svcsubs.c          |   66 +++++++++++++++++++++++++++++++++++++++-----
 fs/nfsd/nfsctl.c            |   65 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/lockd/lockd.h |    7 ++++
 3 files changed, 131 insertions(+), 7 deletions(-)
2008-04-25 13:00:10 -04:00
..
bind.h NLM: Introduce an arguments structure for nlmclnt_init() 2008-01-30 02:06:07 -05:00
debug.h
lockd.h lockd: unlock lockd locks associated with a given server ip 2008-04-25 13:00:10 -04:00
nlm.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
share.h [PATCH] lockd endianness annotations 2006-10-20 10:26:40 -07:00
sm_inter.h lockd: introduce new function to encode private argument in SM_MON requests 2008-03-19 18:01:10 -04:00
xdr4.h NLM: Fix sparse warnings 2007-05-14 19:33:46 -04:00
xdr.h NLM: Fix sign of length of NLM variable length strings 2008-02-01 16:42:02 -05:00