diff options
Diffstat (limited to 'net/ceph')
| -rw-r--r-- | net/ceph/osd_client.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 3b6657fe99b1..015bf9f64da7 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -419,8 +419,18 @@ void ceph_osdc_build_request(struct ceph_osd_request *req, p += 4; /* data */ - if (flags & CEPH_OSD_FLAG_WRITE) - req->r_request->hdr.data_off = cpu_to_le16(off); + if (flags & CEPH_OSD_FLAG_WRITE) { + u16 data_off; + + /* + * The header "data_off" is a hint to the receiver + * allowing it to align received data into its + * buffers such that there's no need to re-copy + * it before writing it to disk (direct I/O). + */ + data_off = (u16) (off & 0xffff); + req->r_request->hdr.data_off = cpu_to_le16(data_off); + } req->r_request->hdr.data_len = cpu_to_le32(data_len); BUG_ON(p > msg->front.iov_base + msg->front.iov_len); |