On Jan 28, 2008, at 9:56 PM, J. Bruce Fields wrote:
On Fri, Jan 25, 2008 at 12:17:30AM -0500, Wendy Cheng wrote:
The logic is implemented on top of linux nfsd procfs with core
functions
residing in lockd kernel module. Entry function is nlmsvc_resume_ip()
where it stores the requested ip interface into a linked-list
nlm_failover_list. The list entry count is nlm_failover_cnt and
access
protection is done by nlm_failover_mutex. Entry in
nlm_failover_ip_list
is a "nlm_failover_struct", defined in: include/linux/lockd/lockd.h.
The list is kept in descending order (newer entry first) based on
g_expire jiffies. For per ip grace period checking, the search
goes thru
the list. As soon as one match ip is found, the search stops. This
implies older entries will not be used and always expire before new
entry. This is to allow multiple entries (for the same ip) to be
added
into the list. The maximum size of the list entries is
NLM_FO_MAX_GP_CNT
(1024).
-- Wendy
The logic is implemented on top of linux nfsd procfs with core
functions
residing in lockd kernel module. Entry function is nlmsvc_resume_ip
() where
it stores the requested ip interface into a linked-list
nlm_failover_list.
The list entry count is nlm_failover_cnt and access protection is
done by
nlm_failover_mutex. Entry in nlm_failover_ip_list is a
"nlm_failover_struct",
defined in: include/linux/lockd/lockd.h.
The list is kept in descending order (newer entry first) based on
g_expire
jiffies. For per ip grace period checking, the search goes thru
the list.
As soon as one match ip is found, the search stops. This implies
older
entries will not be used and always expire before new entry. This
is to allow
multiple entries (for the same ip) to be added into the list. The
maximum size
of the list entries is NLM_FO_MAX_GP_CNT (1024).
Signed-off-by: S. Wendy Cheng <[EMAIL PROTECTED]>
Signed-off-by: Lon Hohberger <[EMAIL PROTECTED]>
fs/lockd/svc.c | 4 +
fs/lockd/svcsubs.c | 159 +++++++++++++++++++++++++++++++
++++++++++++-
include/linux/lockd/lockd.h | 14 +++
3 files changed, 174 insertions(+), 3 deletions(-)
--- linux-2/include/linux/lockd/lockd.h 2008-01-24
17:07:21.000000000 -0500
+++ linux-3/include/linux/lockd/lockd.h 2008-01-24
17:09:26.000000000 -0500
@@ -221,6 +221,20 @@ void nlmsvc_invalidate_all(void);
int nlmsvc_failover_path(struct nameidata *nd);
int nlmsvc_failover_ip(__be32 server_addr);
int nlmsvc_failover_setgrace(void *server_ip, int
ip_size);
+void nlmsvc_failover_reset(void);
+
+#define NLM_FO_MAX_GP_CNT 1024
+
+struct nlm_failover_struct {
+ struct list_head g_list; /* linked list */
+ unsigned long g_expire; /* grace period expire */
+ int g_size; /* g_key type: ipv4 or ipv6 */
+ union {
+ __be32 ipv4; /* ip v4 address */
+ __be32 ipv6[4]; /* ip v6 address */
+ } g_key;
+#define g_ip g_key.ipv6
+};
Only the second member of that union is every used; could we just get
rid of the union?
Also, is that the right choice of types? Maybe we should just use
struct in6_addr?
I agree with Bruce -- just use in_addr, and leave out the unused IPv6
stuff for now.
In some places, we just replace in_addr with in6_addr and simply map
IPv4 to IPv6 addresses, rather than setting up a union.
If the address is used as a hash and never displayed, using a mapped
IPv4 address is sufficient, and keeps things simple.
+
int
nlmsvc_failover_setgrace(void *server_ip, int ip_size)
Should this be
int nlmsvc_failover_setgrace(const struct in_addr *server_ip)
for now, and later we can change it to use in6_addr instead?
{
- /* implemented by resume_002.patch */
- return ENOSYS;
--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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