linux_dsm_epyc7002/include
Chuck Lever f092075dd3 NFS: Always use the same SETCLIENTID boot verifier
Currently our NFS client assigns a unique SETCLIENTID boot verifier
for each server IP address it knows about.  It's set to CURRENT_TIME
when the struct nfs_client for that server IP is created.

During the SETCLIENTID operation, our client also presents an
nfs_client_id4 string to servers, as an identifier on which the server
can hang all of this client's NFSv4 state.  Our client's
nfs_client_id4 string is unique for each server IP address.

An NFSv4 server is obligated to wipe all NFSv4 state associated with
an nfs_client_id4 string when the client presents the same
nfs_client_id4 string along with a changed SETCLIENTID boot verifier.

When our client unmounts the last of a server's shares, it destroys
that server's struct nfs_client.  The next time the client mounts that
NFS server, it creates a fresh struct nfs_client with a fresh boot
verifier.  On seeing the fresh verifer, the server wipes any previous
NFSv4 state associated with that nfs_client_id4.

However, NFSv4.1 clients are supposed to present the same
nfs_client_id4 string to all servers.  And, to support Transparent
State Migration, the same nfs_client_id4 string should be presented
to all NFSv4.0 servers so they recognize that migrated state for this
client belongs with state a server may already have for this client.
(This is known as the Uniform Client String model).

If the nfs_client_id4 string is the same but the boot verifier changes
for each server IP address, SETCLIENTID and EXCHANGE_ID operations
from such a client could unintentionally result in a server wiping a
client's previously obtained lease.

Thus, if our NFS client is going to use a fixed nfs_client_id4 string,
either for NFSv4.0 or NFSv4.1 mounts, our NFS client should use a
boot verifier that does not change depending on server IP address.
Replace our current per-nfs_client boot verifier with a per-nfs_net
boot verifier.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-22 16:45:46 -04:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
asm-generic asm-generic: Use __BITS_PER_LONG in statfs.h 2012-04-30 12:55:15 -07:00
crypto crypto: user - Fix lookup of algorithms with IV generator 2012-03-29 19:52:47 +08:00
drm Merge branch 'exynos-drm-fixes' of git://git.infradead.org/users/kmpark/linux-samsung into drm-intel-fixes 2012-04-12 17:42:01 +01:00
keys
linux NFS: Always use the same SETCLIENTID boot verifier 2012-05-22 16:45:46 -04:00
math-emu
media
misc
mtd
net sctp: check cached dst before using it 2012-05-10 23:15:47 -04:00
pcmcia
rdma
rxrpc
scsi [SCSI] libsas, libata: fix start of life for a sas ata_port 2012-04-23 12:11:47 +01:00
sound ALSA: hda - hide HDMI/ELD printks unless snd.debug=2 2012-04-10 14:53:55 +02:00
target
trace Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-04-04 10:04:42 -07:00
video
xen Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
Kbuild