pnfs: support multiple verfs per direct req
Support direct requests that span multiple pnfs data servers by
comparing nfs_pgio_header->verf to a cached verf in pnfs_commit_bucket.
Continue to use dreq->verf if the MDS is used / non-pNFS.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 2c0e08f..4ad7bc3 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -108,6 +108,97 @@
return atomic_dec_and_test(&dreq->io_count);
}
+/*
+ * nfs_direct_select_verf - select the right verifier
+ * @dreq - direct request possibly spanning multiple servers
+ * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs
+ * @ds_idx - index of data server in data server list, only valid if ds_clp set
+ *
+ * returns the correct verifier to use given the role of the server
+ */
+static struct nfs_writeverf *
+nfs_direct_select_verf(struct nfs_direct_req *dreq,
+ struct nfs_client *ds_clp,
+ int ds_idx)
+{
+ struct nfs_writeverf *verfp = &dreq->verf;
+
+#ifdef CONFIG_NFS_V4_1
+ if (ds_clp) {
+ /* pNFS is in use, use the DS verf */
+ if (ds_idx >= 0 && ds_idx < dreq->ds_cinfo.nbuckets)
+ verfp = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
+ else
+ WARN_ON_ONCE(1);
+ }
+#endif
+ return verfp;
+}
+
+
+/*
+ * nfs_direct_set_hdr_verf - set the write/commit verifier
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verfs
+ *
+ * Set the server's (MDS or DS) "seen" verifier
+ */
+static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq,
+ struct nfs_pgio_header *hdr)
+{
+ struct nfs_writeverf *verfp;
+
+ verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
+ hdr->data->ds_idx);
+ WARN_ON_ONCE(verfp->committed >= 0);
+ memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
+ WARN_ON_ONCE(verfp->committed < 0);
+}
+
+/*
+ * nfs_direct_cmp_hdr_verf - compare verifier for pgio header
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verf
+ *
+ * set the server's "seen" verf if not initialized.
+ * returns result of comparison between @hdr->verf and the "seen"
+ * verf of the server used by @hdr (DS or MDS)
+ */
+static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
+ struct nfs_pgio_header *hdr)
+{
+ struct nfs_writeverf *verfp;
+
+ verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
+ hdr->data->ds_idx);
+ if (verfp->committed < 0) {
+ nfs_direct_set_hdr_verf(dreq, hdr);
+ return 0;
+ }
+ return memcmp(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
+}
+
+#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
+/*
+ * nfs_direct_cmp_commit_data_verf - compare verifier for commit data
+ * @dreq - direct request possibly spanning multiple servers
+ * @data - commit data to validate against previously seen verf
+ *
+ * returns result of comparison between @data->verf and the verf of
+ * the server used by @data (DS or MDS)
+ */
+static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
+ struct nfs_commit_data *data)
+{
+ struct nfs_writeverf *verfp;
+
+ verfp = nfs_direct_select_verf(dreq, data->ds_clp,
+ data->ds_commit_index);
+ WARN_ON_ONCE(verfp->committed < 0);
+ return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf));
+}
+#endif
+
/**
* nfs_direct_IO - NFS address space operation for direct I/O
* @rw: direction (read or write)
@@ -168,6 +259,7 @@
kref_get(&dreq->kref);
init_completion(&dreq->completion);
INIT_LIST_HEAD(&dreq->mds_cinfo.list);
+ dreq->verf.committed = NFS_INVALID_STABLE_HOW; /* not set yet */
INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
spin_lock_init(&dreq->lock);
@@ -602,7 +694,7 @@
dprintk("NFS: %5u commit failed with error %d.\n",
data->task.tk_pid, status);
dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
- } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) {
+ } else if (nfs_direct_cmp_commit_data_verf(dreq, data)) {
dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid);
dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
}
@@ -811,13 +903,13 @@
if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
bit = NFS_IOHDR_NEED_RESCHED;
else if (dreq->flags == 0) {
- memcpy(&dreq->verf, &hdr->verf,
- sizeof(dreq->verf));
+ nfs_direct_set_hdr_verf(dreq, hdr);
bit = NFS_IOHDR_NEED_COMMIT;
dreq->flags = NFS_ODIRECT_DO_COMMIT;
} else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) {
- if (memcmp(&dreq->verf, &hdr->verf, sizeof(dreq->verf))) {
- dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+ if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr)) {
+ dreq->flags =
+ NFS_ODIRECT_RESCHED_WRITES;
bit = NFS_IOHDR_NEED_RESCHED;
} else
bit = NFS_IOHDR_NEED_COMMIT;