CIFS: Reconnect durable handles for SMB2
On reconnects, we need to reopen file and then obtain all byte-range
locks held by the client. SMB2 protocol provides feature to make
this process atomic by reconnecting to the same file handle
with all it's byte-range locks. This patch adds this capability
for SMB2 shares.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 9d7341d..c7ad06f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -857,7 +857,7 @@
return NULL;
buf->ccontext.DataOffset = cpu_to_le16(offsetof
- (struct create_durable, Reserved));
+ (struct create_durable, Data));
buf->ccontext.DataLength = cpu_to_le32(16);
buf->ccontext.NameOffset = cpu_to_le16(offsetof
(struct create_durable, Name));
@@ -869,6 +869,30 @@
return buf;
}
+static struct create_durable *
+create_reconnect_durable_buf(struct cifs_fid *fid)
+{
+ struct create_durable *buf;
+
+ buf = kzalloc(sizeof(struct create_durable), GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->ccontext.DataOffset = cpu_to_le16(offsetof
+ (struct create_durable, Data));
+ buf->ccontext.DataLength = cpu_to_le32(16);
+ buf->ccontext.NameOffset = cpu_to_le16(offsetof
+ (struct create_durable, Name));
+ buf->ccontext.NameLength = cpu_to_le16(4);
+ buf->Data.Fid.PersistentFileId = fid->persistent_fid;
+ buf->Data.Fid.VolatileFileId = fid->volatile_fid;
+ buf->Name[0] = 'D';
+ buf->Name[1] = 'H';
+ buf->Name[2] = 'n';
+ buf->Name[3] = 'C';
+ return buf;
+}
+
static __u8
parse_lease_state(struct smb2_create_rsp *rsp)
{
@@ -924,12 +948,18 @@
}
static int
-add_durable_context(struct kvec *iov, unsigned int *num_iovec)
+add_durable_context(struct kvec *iov, unsigned int *num_iovec,
+ struct cifs_open_parms *oparms)
{
struct smb2_create_req *req = iov[0].iov_base;
unsigned int num = *num_iovec;
- iov[num].iov_base = create_durable_buf();
+ if (oparms->reconnect) {
+ iov[num].iov_base = create_reconnect_durable_buf(oparms->fid);
+ /* indicate that we don't need to relock the file */
+ oparms->reconnect = false;
+ } else
+ iov[num].iov_base = create_durable_buf();
if (iov[num].iov_base == NULL)
return -ENOMEM;
iov[num].iov_len = sizeof(struct create_durable);
@@ -1037,7 +1067,7 @@
(struct create_context *)iov[num_iovecs-1].iov_base;
ccontext->Next = sizeof(struct create_lease);
}
- rc = add_durable_context(iov, &num_iovecs);
+ rc = add_durable_context(iov, &num_iovecs, oparms);
if (rc) {
cifs_small_buf_release(req);
kfree(copy_path);