1 files changed, 89 insertions, 1 deletions

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);