CIFS: Add oplock break support for SMB2

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 78225f5..01479a3 100644 (file)
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -142,8 +142,8 @@ smb2_check_message(char *buf, unsigned int length)
        }
 
        if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
-               if (hdr->Status == 0 ||
-                   pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2) {
+               if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
+                   pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
                        /* error packets have 9 byte structure size */
                        cERROR(1, "Illegal response size %u for command %d",
                                   le16_to_cpu(pdu->StructureSize2), command);
@@ -162,6 +162,9 @@ smb2_check_message(char *buf, unsigned int length)
        if (4 + len != clc_len) {
                cFYI(1, "Calculated size %u length %u mismatch mid %llu",
                        clc_len, 4 + len, mid);
+               /* Windows 7 server returns 24 bytes more */
+               if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
+                       return 0;
                /* server can return one byte more */
                if (clc_len == 4 + len + 1)
                        return 0;
@@ -356,3 +359,72 @@ cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
                                        CIFS_MOUNT_MAP_SPECIAL_CHR);
        return to;
 }
+
+bool
+smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
+{
+       struct smb2_oplock_break *rsp = (struct smb2_oplock_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 oplock break");
+
+       if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
+               return false;
+
+       if (le16_to_cpu(rsp->StructureSize) !=
+                               smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
+               return false;
+       }
+
+       cFYI(1, "oplock level 0x%d", rsp->OplockLevel);
+
+       /* 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);
+                               if (rsp->PersistentFid !=
+                                   cfile->fid.persistent_fid ||
+                                   rsp->VolatileFid !=
+                                   cfile->fid.volatile_fid)
+                                       continue;
+
+                               cFYI(1, "file id match, oplock break");
+                               cinode = CIFS_I(cfile->dentry->d_inode);
+
+                               if (!cinode->clientCanCacheAll &&
+                                   rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
+                                       cfile->oplock_break_cancelled = true;
+                               else
+                                       cfile->oplock_break_cancelled = false;
+
+                               smb2_set_oplock_level(cinode,
+                                 rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);
+
+                               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, "No matching file for oplock break");
+                       return true;
+               }
+       }
+       spin_unlock(&cifs_tcp_ses_lock);
+       cFYI(1, "Can not process oplock break for non-existent connection");
+       return false;
+}

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 2d88c90..8c72e07 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -65,6 +65,17 @@ smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
        server->in_flight--;
        if (server->in_flight == 0 && (optype & CIFS_OP_MASK) != CIFS_NEG_OP)
                rc = change_conf(server);
+       /*
+        * Sometimes server returns 0 credits on oplock break ack - we need to
+        * rebalance credits in this case.
+        */
+       else if (server->in_flight > 0 && server->oplock_credits == 0 &&
+                server->oplocks) {
+               if (server->credits > 1) {
+                       server->credits--;
+                       server->oplock_credits++;
+               }
+       }
        spin_unlock(&server->req_lock);
        wake_up(&server->request_q);
        if (rc)
@@ -502,6 +513,15 @@ smb2_is_status_pending(char *buf, struct TCP_Server_Info *server, int length)
        return true;
 }
 
+static int
+smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
+                    struct cifsInodeInfo *cinode)
+{
+       return SMB2_oplock_break(0, tcon, fid->persistent_fid,
+                                fid->volatile_fid,
+                                cinode->clientCanCacheRead ? 1 : 0);
+}
+
 struct smb_version_operations smb21_operations = {
        .setup_request = smb2_setup_request,
        .setup_async_request = smb2_setup_async_request,
@@ -519,6 +539,7 @@ struct smb_version_operations smb21_operations = {
        .dump_detail = smb2_dump_detail,
        .clear_stats = smb2_clear_stats,
        .print_stats = smb2_print_stats,
+       .is_oplock_break = smb2_is_valid_oplock_break,
        .need_neg = smb2_need_neg,
        .negotiate = smb2_negotiate,
        .negotiate_wsize = smb2_negotiate_wsize,
@@ -556,6 +577,7 @@ struct smb_version_operations smb21_operations = {
        .close_dir = smb2_close_dir,
        .calc_smb_size = smb2_calc_size,
        .is_status_pending = smb2_is_status_pending,
+       .oplock_response = smb2_oplock_response,
 };
 
 struct smb_version_values smb21_values = {

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e97c256..566d86b 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1941,3 +1941,33 @@ SMB2_set_info(const unsigned int xid, struct cifs_tcon *tcon,
                             current->tgid, FILE_BASIC_INFORMATION, 1,
                             (void **)&buf, &size);
 }
+
+int
+SMB2_oplock_break(const unsigned int xid, struct cifs_tcon *tcon,
+                 const u64 persistent_fid, const u64 volatile_fid,
+                 __u8 oplock_level)
+{
+       int rc;
+       struct smb2_oplock_break *req = NULL;
+
+       cFYI(1, "SMB2_oplock_break");
+       rc = small_smb2_init(SMB2_OPLOCK_BREAK, tcon, (void **) &req);
+
+       if (rc)
+               return rc;
+
+       req->VolatileFid = volatile_fid;
+       req->PersistentFid = persistent_fid;
+       req->OplockLevel = oplock_level;
+       req->hdr.CreditRequest = cpu_to_le16(1);
+
+       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 Oplock Break = %d", rc);
+       }
+
+       return rc;
+}

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index e6ddd1f..8a07457 100644 (file)
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -615,6 +615,16 @@ struct smb2_set_info_rsp {
        __le16 StructureSize; /* Must be 2 */
 } __packed;
 
+struct smb2_oplock_break {
+       struct smb2_hdr hdr;
+       __le16 StructureSize; /* Must be 24 */
+       __u8   OplockLevel;
+       __u8   Reserved;
+       __le32 Reserved2;
+       __u64  PersistentFid;
+       __u64  VolatileFid;
+} __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 d18339f..de554b7 100644 (file)
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -49,6 +49,8 @@ extern int smb2_setup_async_request(struct TCP_Server_Info *server,
                                    struct kvec *iov, unsigned int nvec,
                                    struct mid_q_entry **ret_mid);
 extern void smb2_echo_request(struct work_struct *work);
+extern bool smb2_is_valid_oplock_break(char *buffer,
+                                      struct TCP_Server_Info *srv);
 
 extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst,
                                   struct smb2_file_all_info *src);
@@ -133,5 +135,8 @@ extern int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon,
 extern int SMB2_set_info(const unsigned int xid, struct cifs_tcon *tcon,
                         u64 persistent_fid, u64 volatile_fid,
                         FILE_BASIC_INFO *buf);
+extern int SMB2_oplock_break(const unsigned int xid, struct cifs_tcon *tcon,
+                            const u64 persistent_fid, const u64 volatile_fid,
+                            const __u8 oplock_level);
 
 #endif                 /* _SMB2PROTO_H */