CIFS: Add SMB2.1 lease break support

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>

6 files changed, 157 insertions, 14 deletions

diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index 78fb2050e0d6..a93eec30a50d 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -38,6 +38,8 @@ void
 smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
 {
         oplock &= 0xFF;
+        if (oplock == SMB2_OPLOCK_LEVEL_NOCHANGE)
+                return;
         if (oplock == SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
                 cinode->clientCanCacheAll = true;
                 cinode->clientCanCacheRead = true;
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 01479a3fee8d..3a7f8bd5127d 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -148,6 +148,13 @@ smb2_check_message(char *buf, unsigned int length)
                         cERROR(1, "Illegal response size %u for command %d",
                                    le16_to_cpu(pdu->StructureSize2), command);
                         return 1;
+                } else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
+                           && (le16_to_cpu(pdu->StructureSize2) != 44)
+                           && (le16_to_cpu(pdu->StructureSize2) != 36)) {
+                        /* special case for SMB2.1 lease break message */
+                        cERROR(1, "Illegal response size %d for oplock break",
+                                   le16_to_cpu(pdu->StructureSize2));
+                        return 1;
                 }
         }
 
@@ -360,6 +367,84 @@ cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
         return to;
 }
 
+__le32
+smb2_get_lease_state(struct cifsInodeInfo *cinode)
+{
+        if (cinode->clientCanCacheAll)
+                return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING;
+        else if (cinode->clientCanCacheRead)
+                return SMB2_LEASE_READ_CACHING;
+        return 0;
+}
+
+__u8 smb2_map_lease_to_oplock(__le32 lease_state)
+{
+        if (lease_state & SMB2_LEASE_WRITE_CACHING) {
+                if (lease_state & SMB2_LEASE_HANDLE_CACHING)
+                        return SMB2_OPLOCK_LEVEL_BATCH;
+                else
+                        return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
+        } else if (lease_state & SMB2_LEASE_READ_CACHING)
+                return SMB2_OPLOCK_LEVEL_II;
+        return 0;
+}
+
+static bool
+smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
+{
+        struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
+        struct list_head *tmp, *tmp1, *tmp2;
+        struct cifs_ses *ses;
+        struct cifs_tcon *tcon;
+        struct cifsInodeInfo *cinode;
+        struct cifsFileInfo *cfile;
+
+        cFYI(1, "Checking for lease break");
+
+        /* look up tcon based on tid & uid */
+        spin_lock(&cifs_tcp_ses_lock);
+        list_for_each(tmp, &server->smb_ses_list) {
+                ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
+                list_for_each(tmp1, &ses->tcon_list) {
+                        tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
+
+                        cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
+                        spin_lock(&cifs_file_list_lock);
+                        list_for_each(tmp2, &tcon->openFileList) {
+                                cfile = list_entry(tmp2, struct cifsFileInfo,
+                                                     tlist);
+                                cinode = CIFS_I(cfile->dentry->d_inode);
+
+                                if (memcmp(cinode->lease_key, rsp->LeaseKey,
+                                           SMB2_LEASE_KEY_SIZE))
+                                        continue;
+
+                                cFYI(1, "lease key match, lease break 0x%d",
+                                     le32_to_cpu(rsp->NewLeaseState));
+
+                                smb2_set_oplock_level(cinode,
+                                  smb2_map_lease_to_oplock(rsp->NewLeaseState));
+
+                                if (rsp->Flags &
+                                    SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED)
+                                        cfile->oplock_break_cancelled = false;
+                                else
+                                        cfile->oplock_break_cancelled = true;
+
+                                queue_work(cifsiod_wq, &cfile->oplock_break);
+
+                                spin_unlock(&cifs_file_list_lock);
+                                spin_unlock(&cifs_tcp_ses_lock);
+                                return true;
+                        }
+                        spin_unlock(&cifs_file_list_lock);
+                }
+        }
+        spin_unlock(&cifs_tcp_ses_lock);
+        cFYI(1, "Can not process lease break - no lease matched");
+        return false;
+}
+
 bool
 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 {
@@ -377,7 +462,10 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 
         if (le16_to_cpu(rsp->StructureSize) !=
                                 smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
-                return false;
+                if (le16_to_cpu(rsp->StructureSize) == 44)
+                        return smb2_is_valid_lease_break(buffer, server);
+                else
+                        return false;
         }
 
         cFYI(1, "oplock level 0x%d", rsp->OplockLevel);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 360d9079af49..630156f98cc7 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -513,6 +513,10 @@ static int
 smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
                      struct cifsInodeInfo *cinode)
 {
+        if (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
+                return SMB2_lease_break(0, tcon, cinode->lease_key,
+                                        smb2_get_lease_state(cinode));
+
         return SMB2_oplock_break(0, tcon, fid->persistent_fid,
                                  fid->volatile_fid,
                                  cinode->clientCanCacheRead ? 1 : 0);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 89d2824587b2..1572abefb378 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -911,7 +911,6 @@ parse_lease_state(struct smb2_create_rsp *rsp)
 {
         char *data_offset;
         struct create_lease *lc;
-        __u8 oplock = 0;
         bool found = false;
 
         data_offset = (char *)rsp;
@@ -932,19 +931,9 @@ parse_lease_state(struct smb2_create_rsp *rsp)
         } while (le32_to_cpu(lc->ccontext.Next) != 0);
 
         if (!found)
-                return oplock;
-
-        if (le32_to_cpu(lc->lcontext.LeaseState) & SMB2_LEASE_WRITE_CACHING) {
-                if (le32_to_cpu(lc->lcontext.LeaseState) &
-                                                SMB2_LEASE_HANDLE_CACHING)
-                        oplock = SMB2_OPLOCK_LEVEL_BATCH;
-                else
-                        oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
-        } else if (le32_to_cpu(lc->lcontext.LeaseState) &
-                                                SMB2_LEASE_READ_CACHING)
-                oplock = SMB2_OPLOCK_LEVEL_II;
+                return 0;
 
-        return oplock;
+        return smb2_map_lease_to_oplock(lc->lcontext.LeaseState);
 }
 
 int
@@ -2228,3 +2217,34 @@ SMB2_lock(const unsigned int xid, struct cifs_tcon *tcon,
 
         return smb2_lockv(xid, tcon, persist_fid, volatile_fid, pid, 1, &lock);
 }
+
+int
+SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon,
+                 __u8 *lease_key, const __le32 lease_state)
+{
+        int rc;
+        struct smb2_lease_ack *req = NULL;
+
+        cFYI(1, "SMB2_lease_break");
+        rc = small_smb2_init(SMB2_OPLOCK_BREAK, tcon, (void **) &req);
+
+        if (rc)
+                return rc;
+
+        req->hdr.CreditRequest = cpu_to_le16(1);
+        req->StructureSize = cpu_to_le16(36);
+        inc_rfc1001_len(req, 12);
+
+        memcpy(req->LeaseKey, lease_key, 16);
+        req->LeaseState = lease_state;
+
+        rc = SendReceiveNoRsp(xid, tcon->ses, (char *) req, CIFS_OBREAK_OP);
+        /* SMB2 buffer freed by function above */
+
+        if (rc) {
+                cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE);
+                cFYI(1, "Send error in Lease Break = %d", rc);
+        }
+
+        return rc;
+}
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index e818a5cc5bd8..da099225b1a9 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -693,6 +693,31 @@ struct smb2_oplock_break {
         __u64  VolatileFid;
 } __packed;
 
+#define SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED cpu_to_le32(0x01)
+
+struct smb2_lease_break {
+        struct smb2_hdr hdr;
+        __le16 StructureSize; /* Must be 44 */
+        __le16 Reserved;
+        __le32 Flags;
+        __u8   LeaseKey[16];
+        __le32 CurrentLeaseState;
+        __le32 NewLeaseState;
+        __le32 BreakReason;
+        __le32 AccessMaskHint;
+        __le32 ShareMaskHint;
+} __packed;
+
+struct smb2_lease_ack {
+        struct smb2_hdr hdr;
+        __le16 StructureSize; /* Must be 36 */
+        __le16 Reserved;
+        __le32 Flags;
+        __u8   LeaseKey[16];
+        __le32 LeaseState;
+        __le64 LeaseDuration;
+} __packed;
+
 /*
  *      PDU infolevel structure definitions
  *      BB consider moving to a different header
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 8b4d3712255b..7d25f8b14f93 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -48,6 +48,8 @@ extern struct mid_q_entry *smb2_setup_request(struct cifs_ses *ses,
 extern struct mid_q_entry *smb2_setup_async_request(
                         struct TCP_Server_Info *server, struct smb_rqst *rqst);
 extern void smb2_echo_request(struct work_struct *work);
+extern __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode);
+extern __u8 smb2_map_lease_to_oplock(__le32 lease_state);
 extern bool smb2_is_valid_oplock_break(char *buffer,
                                        struct TCP_Server_Info *srv);
 
@@ -151,5 +153,7 @@ extern int smb2_lockv(const unsigned int xid, struct cifs_tcon *tcon,
                       const __u64 persist_fid, const __u64 volatile_fid,
                       const __u32 pid, const __u32 num_lock,
                       struct smb2_lock_element *buf);
+extern int SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon,
+                            __u8 *lease_key, const __le32 lease_state);
 
 #endif                  /* _SMB2PROTO_H */