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@xxxxxxxxxxxxxxx>
---
fs/nfs/direct.c | 84 ++++++++++++++++++++++++++++++++++++++++++-------
fs/nfs/nfs4filelayout.c | 3 ++
include/linux/nfs.h | 5 ++-
include/linux/nfs_xdr.h | 2 ++
4 files changed, 82 insertions(+), 12 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 9d968ca..53b86e6 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -90,7 +90,7 @@ struct nfs_direct_req {
int flags;
#define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */
#define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */
- struct nfs_writeverf verf; /* unstable write verifier */
+ struct nfs_writeverf verf; /* unstable write verifier */
};
static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops;
@@ -108,6 +108,70 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
return atomic_dec_and_test(&dreq->io_count);
}
+/*
+ * nfs_direct_set_or_cmp_hdr_verf - ensure that the same verifier is used
+ * for all requests (to each sever) in a
+ * direct io request.
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verfs
+ *
+ * If a verf has yet to be seen for the server associated with @hdr, set
+ * the verf for that server and return 0.
+ * If a verf has been seen for this server, compare @hdr->verf to it and
+ * return the result.
+ */
+static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
+ struct nfs_pgio_header *hdr)
+{
+ struct nfs_writeverf *ds_verf = &dreq->verf;
+ struct nfs_client *ds_clp = hdr->data.write->ds_clp;
+ int ds_idx = hdr->data.write->ds_idx;
+
+ if (ds_clp) {
+ /* pNFS is in use, use the DS verf */
+ if (ds_idx > dreq->ds_cinfo.nbuckets)
+ WARN_ON_ONCE(1);
+ else
+ ds_verf = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
+ }
+ if (ds_verf->committed < 0) {
+ memcpy(ds_verf, hdr->verf, sizeof(struct nfs_writeverf));
+ WARN_ON_ONCE(ds_verf->committed < 0);
+ return 0;
+ }
+ return memcmp(ds_verf, hdr->verf, sizeof(struct nfs_writeverf));
+}
+
+/*
+ * nfs_direct_cmp_commit_data_verf - check that a write verifier from a commit
+ * matches the verifier seen on write from
+ * the same server.
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verfs
+ *
+ * This function relies on nfs_direct_set_or_cmp_hdr_verf being called at least
+ * once to set the verf for this server - this is OK because both called (and
+ * only called) in the unstable write path.
+ *
+ * Compare @hdr->verf to it and return the result.
+ */
+static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
+ struct nfs_commit_data *data)
+{
+ struct nfs_writeverf *ds_verf = &dreq->verf;
+ int ds_idx = data->ds_commit_index;
+
+ if (data->ds_clp) {
+ /* pNFS is in use, use the DS verf */
+ if (ds_idx > dreq->ds_cinfo.nbuckets)
+ WARN_ON_ONCE(1);
+ else
+ ds_verf = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
+ }
+ WARN_ON_ONCE(ds_verf->committed < 0);
+ return memcmp(ds_verf, &data->verf, sizeof(struct nfs_writeverf));
+}
+
/**
* nfs_direct_IO - NFS address space operation for direct I/O
* @rw: direction (read or write)
@@ -168,6 +232,7 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
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 +667,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
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;
}
@@ -810,16 +875,13 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
} else if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) {
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));
- 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;
+ else {
+ if (dreq->flags == 0)
+ dreq->flags = NFS_ODIRECT_DO_COMMIT;
+
+ if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr))
bit = NFS_IOHDR_NEED_RESCHED;
- } else
+ else
bit = NFS_IOHDR_NEED_COMMIT;
}
}
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index cfd76bd..9a91f4f 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -603,6 +603,7 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
data->write_done_cb = filelayout_write_done_cb;
atomic_inc(&ds->ds_clp->cl_count);
data->ds_clp = ds->ds_clp;
+ data->ds_idx = idx;
fh = nfs4_fl_select_ds_fh(lseg, j);
if (fh)
data->args.fh = fh;
@@ -875,6 +876,8 @@ filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
for (i = 0; i < size; i++) {
INIT_LIST_HEAD(&buckets[i].written);
INIT_LIST_HEAD(&buckets[i].committing);
+ /* mark direct verifier as unset */
+ buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
}
spin_lock(cinfo->lock);
diff --git a/include/linux/nfs.h b/include/linux/nfs.h
index 3e794c1..610af51 100644
--- a/include/linux/nfs.h
+++ b/include/linux/nfs.h
@@ -46,6 +46,9 @@ static inline void nfs_copy_fh(struct nfs_fh *target, const struct nfs_fh *sourc
enum nfs3_stable_how {
NFS_UNSTABLE = 0,
NFS_DATA_SYNC = 1,
- NFS_FILE_SYNC = 2
+ NFS_FILE_SYNC = 2,
+
+ /* used by direct.c to mark verf as invalid */
+ NFS_INVALID_STABLE_HOW = -1
};
#endif /* _LINUX_NFS_H */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 239274d..f94d804 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1129,6 +1129,7 @@ struct pnfs_commit_bucket {
struct list_head committing;
struct pnfs_layout_segment *wlseg;
struct pnfs_layout_segment *clseg;
+ struct nfs_writeverf direct_verf;
};
struct pnfs_ds_commit_info {
@@ -1289,6 +1290,7 @@ struct nfs_write_data {
__u64 mds_offset; /* Filelayout dense stripe */
struct nfs_page_array pages;
struct nfs_client *ds_clp; /* pNFS data server */
+ int ds_idx; /* ds index if ds_clp is set */
};
/* used as flag bits in nfs_pgio_header */
--
1.8.5.2 (Apple Git-48)
--
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