nfsd: fix pNFS return on close semantics
For the sake of forgetful clients, the server should return the layouts
to the file system on 'last close' of a file (assuming that there are no
delegations outstanding to that particular client) or on delegreturn
(assuming that there are no opens on a file from that particular
client).
In theory the information is all there in current data structures, but
it's not efficiently available; nfs4_file->fi_ref includes references on
the file across all clients, but we need a per-(client, file) count.
Walking through lots of stateid's to calculate this on each close or
delegreturn would be painful.
This patch introduces infrastructure to maintain per-client opens and
delegation counters on a per-file basis.
[hch: ported to the mainline pNFS support, merged various fixes from Jeff]
Signed-off-by: Sachin Bhamare <sachin.bhamare@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 4f3bfeb..bde45d9 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -126,6 +126,7 @@
struct list_head dl_perfile;
struct list_head dl_perclnt;
struct list_head dl_recall_lru; /* delegation recalled */
+ struct nfs4_clnt_odstate *dl_clnt_odstate;
u32 dl_type;
time_t dl_time;
/* For recall: */
@@ -465,6 +466,17 @@
}
/*
+ * Per-client state indicating no. of opens and outstanding delegations
+ * on a file from a particular client.'od' stands for 'open & delegation'
+ */
+struct nfs4_clnt_odstate {
+ struct nfs4_client *co_client;
+ struct nfs4_file *co_file;
+ struct list_head co_perfile;
+ atomic_t co_odcount;
+};
+
+/*
* nfs4_file: a file opened by some number of (open) nfs4_stateowners.
*
* These objects are global. nfsd keeps one instance of a nfs4_file per
@@ -485,6 +497,7 @@
struct list_head fi_delegations;
struct rcu_head fi_rcu;
};
+ struct list_head fi_clnt_odstate;
/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
struct file * fi_fds[3];
/*
@@ -526,6 +539,7 @@
struct list_head st_perstateowner;
struct list_head st_locks;
struct nfs4_stateowner * st_stateowner;
+ struct nfs4_clnt_odstate * st_clnt_odstate;
unsigned char st_access_bmap;
unsigned char st_deny_bmap;
struct nfs4_ol_stateid * st_openstp;