qubes-linux-kernel/patches.fixes/nfsd-06-sunrpc-cache-retry-cache-lookups-that-return-ETIMEDO.patch
2010-07-07 13:12:45 +02:00

128 lines
3.4 KiB
Diff

Patch-mainline: submitted 04aug2009
References: bnc#498708
From: NeilBrown <neilb@suse.de>
Date: Tue, 4 Aug 2009 15:06:38 +1000
Subject: [PATCH 08/12] sunrpc/cache: retry cache lookups that return -ETIMEDOUT
If cache_check returns -ETIMEDOUT, then the cache item is not
up-to-date, but there is no pending upcall.
This could mean the data is not available, or it could mean that the
good data has been stored in a new cache item.
So re-do the lookup and if that returns a new item, proceed using that
item.
Signed-off-by: NeilBrown <neilb@suse.de>
---
fs/nfsd/export.c | 18 ++++++++++++++++++
net/sunrpc/svcauth_unix.c | 23 ++++++++++++++++++++---
2 files changed, 38 insertions(+), 3 deletions(-)
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -787,9 +787,18 @@ exp_find_key(svc_client *clp, int fsid_t
memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
ek = svc_expkey_lookup(&key);
+ again:
if (ek == NULL)
return ERR_PTR(-ENOMEM);
err = cache_check(&svc_expkey_cache, &ek->h, reqp);
+ if (err == -ETIMEDOUT) {
+ struct svc_expkey *prev_ek = ek;
+ ek = svc_expkey_lookup(&key);
+ if (ek != prev_ek)
+ goto again;
+ if (ek)
+ cache_put(&ek->h, &svc_expkey_cache);
+ }
if (err)
return ERR_PTR(err);
return ek;
@@ -859,9 +868,18 @@ static svc_export *exp_get_by_name(svc_c
key.ex_path = *path;
exp = svc_export_lookup(&key);
+ retry:
if (exp == NULL)
return ERR_PTR(-ENOMEM);
err = cache_check(&svc_export_cache, &exp->h, reqp);
+ if (err == -ETIMEDOUT) {
+ struct svc_export *prev_exp = exp;
+ exp = svc_export_lookup(&key);
+ if (exp != prev_exp)
+ goto retry;
+ if (exp)
+ cache_put(&exp->h, &svc_export_cache);
+ }
if (err)
return ERR_PTR(err);
return exp;
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -662,13 +662,14 @@ static struct unix_gid *unix_gid_lookup(
static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
{
- struct unix_gid *ug;
+ struct unix_gid *ug, *prevug;
struct group_info *gi;
int ret;
ug = unix_gid_lookup(uid);
if (!ug)
return ERR_PTR(-EAGAIN);
+retry:
ret = cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle);
switch (ret) {
case -ENOENT:
@@ -677,6 +678,13 @@ static struct group_info *unix_gid_find(
gi = get_group_info(ug->gi);
cache_put(&ug->h, &unix_gid_cache);
return gi;
+ case -ETIMEDOUT:
+ prevug = ug;
+ ug = unix_gid_lookup(uid);
+ if (ug != prevug)
+ goto retry;
+ if (ug)
+ cache_put(&ug->h, &unix_gid_cache);
default:
return ERR_PTR(-EAGAIN);
}
@@ -687,7 +695,7 @@ svcauth_unix_set_client(struct svc_rqst
{
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6, sin6_storage;
- struct ip_map *ipm;
+ struct ip_map *ipm, *prev_ipm;
struct group_info *gi;
struct svc_cred *cred = &rqstp->rq_cred;
@@ -713,14 +721,23 @@ svcauth_unix_set_client(struct svc_rqst
ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
&sin6->sin6_addr);
+ retry:
if (ipm == NULL)
return SVC_DENIED;
switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
default:
BUG();
- case -EAGAIN:
case -ETIMEDOUT:
+ prev_ipm = ipm;
+ ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
+ &sin6->sin6_addr);
+ if (ipm != prev_ipm)
+ goto retry;
+ if (ipm)
+ cache_put(&ipm->h, &ip_map_cache);
+
+ case -EAGAIN:
return SVC_DROP;
case -ENOENT:
return SVC_DENIED;