summaryrefslogtreecommitdiffstats
path: root/fs/nfsd/nfs4layouts.c
diff options
context:
space:
mode:
authorJeff Layton <jlayton@poochiereds.net>2015-09-17 07:58:24 -0400
committerJ. Bruce Fields <bfields@redhat.com>2015-10-23 15:57:32 -0400
commitcc8a55320b5f1196bee5bd14e4bb2ebd3b983317 (patch)
treed5b6e13f764cc2c0a37d8676662302e09e1ec020 /fs/nfsd/nfs4layouts.c
parent4eaea13425078272895ec37814c6878d78b8db9f (diff)
downloadlinux-cc8a55320b5f1196bee5bd14e4bb2ebd3b983317.tar.bz2
nfsd: serialize layout stateid morphing operations
In order to allow the client to make a sane determination of what happened with racing LAYOUTGET/LAYOUTRETURN/CB_LAYOUTRECALL calls, we must ensure that the seqids return accurately represent the order of operations. The simplest way to do that is to ensure that operations on a single stateid are serialized. This patch adds a mutex to the layout stateid, and locks it when checking the layout stateid's seqid. The mutex is held over the entire operation and released after the seqid is bumped. Note that in the case of CB_LAYOUTRECALL we must move the increment of the seqid and setting into a new cb "prepare" operation. The lease infrastructure will call the lm_break callback with a spinlock held, so and we can't take the mutex in that codepath. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd/nfs4layouts.c')
-rw-r--r--fs/nfsd/nfs4layouts.c25
1 files changed, 21 insertions, 4 deletions
diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index ebf90e487c75..4a68ab901b4b 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -201,6 +201,7 @@ nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
INIT_LIST_HEAD(&ls->ls_perfile);
spin_lock_init(&ls->ls_lock);
INIT_LIST_HEAD(&ls->ls_layouts);
+ mutex_init(&ls->ls_mutex);
ls->ls_layout_type = layout_type;
nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
NFSPROC4_CLNT_CB_LAYOUT);
@@ -262,19 +263,23 @@ nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
status = nfserr_jukebox;
if (!ls)
goto out;
+ mutex_lock(&ls->ls_mutex);
} else {
ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
status = nfserr_bad_stateid;
+ mutex_lock(&ls->ls_mutex);
if (stateid->si_generation > stid->sc_stateid.si_generation)
- goto out_put_stid;
+ goto out_unlock_stid;
if (layout_type != ls->ls_layout_type)
- goto out_put_stid;
+ goto out_unlock_stid;
}
*lsp = ls;
return 0;
+out_unlock_stid:
+ mutex_unlock(&ls->ls_mutex);
out_put_stid:
nfs4_put_stid(stid);
out:
@@ -296,8 +301,6 @@ nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
trace_layout_recall(&ls->ls_stid.sc_stateid);
atomic_inc(&ls->ls_stid.sc_count);
- update_stateid(&ls->ls_stid.sc_stateid);
- memcpy(&ls->ls_recall_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
nfsd4_run_cb(&ls->ls_recall);
out_unlock:
@@ -494,6 +497,7 @@ nfsd4_return_file_layouts(struct svc_rqst *rqstp,
}
spin_unlock(&ls->ls_lock);
+ mutex_unlock(&ls->ls_mutex);
nfs4_put_stid(&ls->ls_stid);
nfsd4_free_layouts(&reaplist);
return nfs_ok;
@@ -608,6 +612,17 @@ nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
}
}
+static void
+nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
+{
+ struct nfs4_layout_stateid *ls =
+ container_of(cb, struct nfs4_layout_stateid, ls_recall);
+
+ mutex_lock(&ls->ls_mutex);
+ update_stateid(&ls->ls_stid.sc_stateid);
+ memcpy(&ls->ls_recall_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
+}
+
static int
nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
{
@@ -649,12 +664,14 @@ nfsd4_cb_layout_release(struct nfsd4_callback *cb)
trace_layout_recall_release(&ls->ls_stid.sc_stateid);
+ mutex_unlock(&ls->ls_mutex);
nfsd4_return_all_layouts(ls, &reaplist);
nfsd4_free_layouts(&reaplist);
nfs4_put_stid(&ls->ls_stid);
}
static struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
+ .prepare = nfsd4_cb_layout_prepare,
.done = nfsd4_cb_layout_done,
.release = nfsd4_cb_layout_release,
};