[PATCH] knfsd: nfsd: don't drop silently on upcall deferral
To avoid tying up server threads when nfsd makes an upcall (to mountd, to get
export options, to idmapd, for nfsv4 name<->id mapping, etc.), we temporarily
"drop" the request and save enough information so that we can revisit it
later.
Certain failures during the deferral process can cause us to really drop the
request and never revisit it.
This is often less than ideal, and is unacceptable in the NFSv4 case--rfc 3530
forbids the server from dropping a request without also closing the
connection.
As a first step, we modify the deferral code to return -ETIMEDOUT (which is
translated to nfserr_jukebox in the v3 and v4 cases, and remains a drop in the
v2 case).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index b0591cd..1137d09 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -787,15 +787,20 @@
key.ex_dentry = dentry;
exp = svc_export_lookup(&key);
- if (exp != NULL)
- switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
+ if (exp != NULL) {
+ int err;
+
+ err = cache_check(&svc_export_cache, &exp->h, reqp);
+ switch (err) {
case 0: break;
case -EAGAIN:
- exp = ERR_PTR(-EAGAIN);
+ case -ETIMEDOUT:
+ exp = ERR_PTR(err);
break;
default:
exp = NULL;
}
+ }
return exp;
}
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 727ab3b..b06bf9f 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -169,9 +169,11 @@
exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
}
- error = nfserr_dropit;
- if (IS_ERR(exp) && PTR_ERR(exp) == -EAGAIN)
+ if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN
+ || PTR_ERR(exp) == -ETIMEDOUT)) {
+ error = nfserrno(PTR_ERR(exp));
goto out;
+ }
error = nfserr_stale;
if (!exp || IS_ERR(exp))
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 4883d75..7a79c23 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -99,7 +99,7 @@
/*
* Called from nfsd_lookup and encode_dirent. Check if we have crossed
* a mount point.
- * Returns -EAGAIN leaving *dpp and *expp unchanged,
+ * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
* or nfs_ok having possibly changed *dpp and *expp
*/
int