ceph: allocate sparse_ext map only for sparse reads

idryomov · idryomov · commit 18d44c5d062b · 2024-12-16T23:25:44.000+01:00
If mounted with sparseread option, ceph_direct_read_write() ends up making an unnecessarily allocation for O_DIRECT writes. Fixes: 03bc06c ("ceph: add new mount option to enable sparse reads") Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Alex Markuze <amarkuze@redhat.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
@@ -1552,7 +1552,7 @@ 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
@@ -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),

Original file line number	Diff line number	Diff line change
`@@ -1552,7 +1552,7 @@ ceph_direct_read_write(struct kiocb iocb, struct iov_iter iter,`
`1552`	`1552`	`}`
`1553`	`1553`
`1554`	`1554`	`op = &req->r_ops[0];`
`1555`		`- if (sparse) {`
	`1555`	`+ if (!write && sparse) {`
`1556`	`1556`	`extent_cnt = __ceph_sparse_read_ext_count(inode, size);`
`1557`	`1557`	`ret = ceph_alloc_sparse_ext_map(op, extent_cnt);`
`1558`	`1558`	`if (ret) {`
Original file line number	Diff line number	Diff line change
`@@ -1173,6 +1173,8 @@ EXPORT_SYMBOL(ceph_osdc_new_request);`
`1173`	`1173`
`1174`	`1174`	`int __ceph_alloc_sparse_ext_map(struct ceph_osd_req_op *op, int cnt)`
`1175`	`1175`	`{`
	`1176`	`+ WARN_ON(op->op != CEPH_OSD_OP_SPARSE_READ);`
	`1177`	`+`
`1176`	`1178`	`op->extent.sparse_ext_cnt = cnt;`
`1177`	`1179`	`op->extent.sparse_ext = kmalloc_array(cnt,`
`1178`	`1180`	`sizeof(*op->extent.sparse_ext),`