From 9cbc0b7339b0542a1d13922d2745a2636ce44853 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Tue, 9 Jul 2013 18:40:58 +0400 Subject: 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 Signed-off-by: Steven French --- fs/cifs/smb2pdu.c | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) (limited to 'fs/cifs/smb2pdu.c') diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 9d7341d696fc..c7ad06fc9d63 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -857,7 +857,7 @@ create_durable_buf(void) 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 @@ create_durable_buf(void) 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 @@ add_lease_context(struct kvec *iov, unsigned int *num_iovec, __u8 *oplock) } 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 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path, (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); -- cgit v1.2.3