[PATCH 2/2] ceph: allocate sparse_ext map only for sparse reads

[Ilya Dryomov <idryomov@gmail.com>]

If mounted with sparseread option, ceph_direct_read_write() ends up
making an unnecessarily allocation for O_DIRECT writes.

Fixes: 03bc06c7b0bd ("ceph: add new mount option to enable sparse reads")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/ceph/file.c        | 2 +-
 net/ceph/osd_client.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 0df2ffc69e92..f17bc4dc629c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1558,7 +1558,7 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 		}
 
 		op = &req->r_ops[0];
-		if (sparse) {
+		if (!write && sparse) {
 			extent_cnt = __ceph_sparse_read_ext_count(inode, size);
 			ret = ceph_alloc_sparse_ext_map(op, extent_cnt);
 			if (ret) {
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 9b1168eb77ab..b24afec24138 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1173,6 +1173,8 @@ EXPORT_SYMBOL(ceph_osdc_new_request);
 
 int __ceph_alloc_sparse_ext_map(struct ceph_osd_req_op *op, int cnt)
 {
+	WARN_ON(op->op != CEPH_OSD_OP_SPARSE_READ);
+
 	op->extent.sparse_ext_cnt = cnt;
 	op->extent.sparse_ext = kmalloc_array(cnt,
 					      sizeof(*op->extent.sparse_ext),
-- 
2.46.1