Initial import

1 files changed, 632 insertions, 0 deletions

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
new file mode 100644
index 000000000..1c5907019
--- /dev/null
+++ b/fs/cifs/smb2misc.c
@@ -0,0 +1,632 @@
+/*
+ *   fs/cifs/smb2misc.c
+ *
+ *   Copyright (C) International Business Machines  Corp., 2002,2011
+ *                 Etersoft, 2012
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *              Pavel Shilovsky (pshilovsky@samba.org) 2012
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Lesser General Public License as published
+ *   by the Free Software Foundation; either version 2.1 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This library is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU Lesser General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Lesser General Public License
+ *   along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/ctype.h>
+#include "smb2pdu.h"
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "smb2proto.h"
+#include "cifs_debug.h"
+#include "cifs_unicode.h"
+#include "smb2status.h"
+
+static int
+check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
+{
+	__u64 wire_mid = le64_to_cpu(hdr->MessageId);
+
+	/*
+	 * Make sure that this really is an SMB, that it is a response,
+	 * and that the message ids match.
+	 */
+	if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
+	    (mid == wire_mid)) {
+		if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
+			return 0;
+		else {
+			/* only one valid case where server sends us request */
+			if (hdr->Command == SMB2_OPLOCK_BREAK)
+				return 0;
+			else
+				cifs_dbg(VFS, "Received Request not response\n");
+		}
+	} else { /* bad signature or mid */
+		if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
+			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
+				 *(unsigned int *) hdr->ProtocolId);
+		if (mid != wire_mid)
+			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
+				 mid, wire_mid);
+	}
+	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
+	return 1;
+}
+
+/*
+ *  The following table defines the expected "StructureSize" of SMB2 responses
+ *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
+ *
+ *  Note that commands are defined in smb2pdu.h in le16 but the array below is
+ *  indexed by command in host byte order
+ */
+static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
+	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
+	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
+	/* SMB2_LOGOFF */ cpu_to_le16(4),
+	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
+	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
+	/* SMB2_CREATE */ cpu_to_le16(89),
+	/* SMB2_CLOSE */ cpu_to_le16(60),
+	/* SMB2_FLUSH */ cpu_to_le16(4),
+	/* SMB2_READ */ cpu_to_le16(17),
+	/* SMB2_WRITE */ cpu_to_le16(17),
+	/* SMB2_LOCK */ cpu_to_le16(4),
+	/* SMB2_IOCTL */ cpu_to_le16(49),
+	/* BB CHECK this ... not listed in documentation */
+	/* SMB2_CANCEL */ cpu_to_le16(0),
+	/* SMB2_ECHO */ cpu_to_le16(4),
+	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
+	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
+	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
+	/* SMB2_SET_INFO */ cpu_to_le16(2),
+	/* BB FIXME can also be 44 for lease break */
+	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
+};
+
+int
+smb2_check_message(char *buf, unsigned int length)
+{
+	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
+	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
+	__u64 mid = le64_to_cpu(hdr->MessageId);
+	__u32 len = get_rfc1002_length(buf);
+	__u32 clc_len;  /* calculated length */
+	int command;
+
+	/* BB disable following printk later */
+	cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
+		 __func__, length, len);
+
+	/*
+	 * Add function to do table lookup of StructureSize by command
+	 * ie Validate the wct via smb2_struct_sizes table above
+	 */
+
+	if (length < sizeof(struct smb2_pdu)) {
+		if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
+			pdu->StructureSize2 = 0;
+			/*
+			 * As with SMB/CIFS, on some error cases servers may
+			 * not return wct properly
+			 */
+			return 0;
+		} else {
+			cifs_dbg(VFS, "Length less than SMB header size\n");
+		}
+		return 1;
+	}
+	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
+		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
+			 mid);
+		return 1;
+	}
+
+	if (check_smb2_hdr(hdr, mid))
+		return 1;
+
+	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
+		cifs_dbg(VFS, "Illegal structure size %u\n",
+			 le16_to_cpu(hdr->StructureSize));
+		return 1;
+	}
+
+	command = le16_to_cpu(hdr->Command);
+	if (command >= NUMBER_OF_SMB2_COMMANDS) {
+		cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
+		return 1;
+	}
+
+	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
+		if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
+		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
+			/* error packets have 9 byte structure size */
+			cifs_dbg(VFS, "Illegal response size %u for command %d\n",
+				 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 */
+			cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
+				 le16_to_cpu(pdu->StructureSize2));
+			return 1;
+		}
+	}
+
+	if (4 + len != length) {
+		cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
+			 length, 4 + len, mid);
+		return 1;
+	}
+
+	clc_len = smb2_calc_size(hdr);
+
+	if (4 + len != clc_len) {
+		cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
+			 clc_len, 4 + len, mid);
+		/* create failed on symlink */
+		if (command == SMB2_CREATE_HE &&
+		    hdr->Status == STATUS_STOPPED_ON_SYMLINK)
+			return 0;
+		/* 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 due to implied bcc[0] */
+		if (clc_len == 4 + len + 1)
+			return 0;
+
+		/*
+		 * MacOS server pads after SMB2.1 write response with 3 bytes
+		 * of junk. Other servers match RFC1001 len to actual
+		 * SMB2/SMB3 frame length (header + smb2 response specific data)
+		 * Log the server error (once), but allow it and continue
+		 * since the frame is parseable.
+		 */
+		if (clc_len < 4 /* RFC1001 header size */ + len) {
+			printk_once(KERN_WARNING
+				"SMB2 server sent bad RFC1001 len %d not %d\n",
+				len, clc_len - 4);
+			return 0;
+		}
+
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * The size of the variable area depends on the offset and length fields
+ * located in different fields for various SMB2 responses. SMB2 responses
+ * with no variable length info, show an offset of zero for the offset field.
+ */
+static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
+	/* SMB2_NEGOTIATE */ true,
+	/* SMB2_SESSION_SETUP */ true,
+	/* SMB2_LOGOFF */ false,
+	/* SMB2_TREE_CONNECT */	false,
+	/* SMB2_TREE_DISCONNECT */ false,
+	/* SMB2_CREATE */ true,
+	/* SMB2_CLOSE */ false,
+	/* SMB2_FLUSH */ false,
+	/* SMB2_READ */	true,
+	/* SMB2_WRITE */ false,
+	/* SMB2_LOCK */	false,
+	/* SMB2_IOCTL */ true,
+	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
+	/* SMB2_ECHO */ false,
+	/* SMB2_QUERY_DIRECTORY */ true,
+	/* SMB2_CHANGE_NOTIFY */ true,
+	/* SMB2_QUERY_INFO */ true,
+	/* SMB2_SET_INFO */ false,
+	/* SMB2_OPLOCK_BREAK */ false
+};
+
+/*
+ * Returns the pointer to the beginning of the data area. Length of the data
+ * area and the offset to it (from the beginning of the smb are also returned.
+ */
+char *
+smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
+{
+	*off = 0;
+	*len = 0;
+
+	/* error responses do not have data area */
+	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
+	    (((struct smb2_err_rsp *)hdr)->StructureSize) ==
+						SMB2_ERROR_STRUCTURE_SIZE2)
+		return NULL;
+
+	/*
+	 * Following commands have data areas so we have to get the location
+	 * of the data buffer offset and data buffer length for the particular
+	 * command.
+	 */
+	switch (hdr->Command) {
+	case SMB2_NEGOTIATE:
+		*off = le16_to_cpu(
+		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
+		*len = le16_to_cpu(
+		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
+		break;
+	case SMB2_SESSION_SETUP:
+		*off = le16_to_cpu(
+		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
+		*len = le16_to_cpu(
+		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
+		break;
+	case SMB2_CREATE:
+		*off = le32_to_cpu(
+		    ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
+		*len = le32_to_cpu(
+		    ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
+		break;
+	case SMB2_QUERY_INFO:
+		*off = le16_to_cpu(
+		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
+		*len = le32_to_cpu(
+		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
+		break;
+	case SMB2_READ:
+		*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
+		*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
+		break;
+	case SMB2_QUERY_DIRECTORY:
+		*off = le16_to_cpu(
+		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
+		*len = le32_to_cpu(
+		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
+		break;
+	case SMB2_IOCTL:
+		*off = le32_to_cpu(
+		  ((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
+		*len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
+		break;
+	case SMB2_CHANGE_NOTIFY:
+	default:
+		/* BB FIXME for unimplemented cases above */
+		cifs_dbg(VFS, "no length check for command\n");
+		break;
+	}
+
+	/*
+	 * Invalid length or offset probably means data area is invalid, but
+	 * we have little choice but to ignore the data area in this case.
+	 */
+	if (*off > 4096) {
+		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
+		*len = 0;
+		*off = 0;
+	} else if (*off < 0) {
+		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
+			 *off);
+		*off = 0;
+		*len = 0;
+	} else if (*len < 0) {
+		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
+			 *len);
+		*len = 0;
+	} else if (*len > 128 * 1024) {
+		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
+		*len = 0;
+	}
+
+	/* return pointer to beginning of data area, ie offset from SMB start */
+	if ((*off != 0) && (*len != 0))
+		return (char *)(&hdr->ProtocolId[0]) + *off;
+	else
+		return NULL;
+}
+
+/*
+ * Calculate the size of the SMB message based on the fixed header
+ * portion, the number of word parameters and the data portion of the message.
+ */
+unsigned int
+smb2_calc_size(void *buf)
+{
+	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
+	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
+	int offset; /* the offset from the beginning of SMB to data area */
+	int data_length; /* the length of the variable length data area */
+	/* Structure Size has already been checked to make sure it is 64 */
+	int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
+
+	/*
+	 * StructureSize2, ie length of fixed parameter area has already
+	 * been checked to make sure it is the correct length.
+	 */
+	len += le16_to_cpu(pdu->StructureSize2);
+
+	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
+		goto calc_size_exit;
+
+	smb2_get_data_area_len(&offset, &data_length, hdr);
+	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
+
+	if (data_length > 0) {
+		/*
+		 * Check to make sure that data area begins after fixed area,
+		 * Note that last byte of the fixed area is part of data area
+		 * for some commands, typically those with odd StructureSize,
+		 * so we must add one to the calculation (and 4 to account for
+		 * the size of the RFC1001 hdr.
+		 */
+		if (offset + 4 + 1 < len) {
+			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
+				 offset + 4 + 1, len);
+			data_length = 0;
+		} else {
+			len = 4 + offset + data_length;
+		}
+	}
+calc_size_exit:
+	cifs_dbg(FYI, "SMB2 len %d\n", len);
+	return len;
+}
+
+/* Note: caller must free return buffer */
+__le16 *
+cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
+{
+	int len;
+	const char *start_of_path;
+	__le16 *to;
+	int map_type;
+
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
+		map_type = SFM_MAP_UNI_RSVD;
+	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
+		map_type = SFU_MAP_UNI_RSVD;
+	else
+		map_type = NO_MAP_UNI_RSVD;
+
+	/* Windows doesn't allow paths beginning with \ */
+	if (from[0] == '\\')
+		start_of_path = from + 1;
+	else
+		start_of_path = from;
+	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
+				   cifs_sb->local_nls, map_type);
+	return to;
+}
+
+__le32
+smb2_get_lease_state(struct cifsInodeInfo *cinode)
+{
+	__le32 lease = 0;
+
+	if (CIFS_CACHE_WRITE(cinode))
+		lease |= SMB2_LEASE_WRITE_CACHING;
+	if (CIFS_CACHE_HANDLE(cinode))
+		lease |= SMB2_LEASE_HANDLE_CACHING;
+	if (CIFS_CACHE_READ(cinode))
+		lease |= SMB2_LEASE_READ_CACHING;
+	return lease;
+}
+
+struct smb2_lease_break_work {
+	struct work_struct lease_break;
+	struct tcon_link *tlink;
+	__u8 lease_key[16];
+	__le32 lease_state;
+};
+
+static void
+cifs_ses_oplock_break(struct work_struct *work)
+{
+	struct smb2_lease_break_work *lw = container_of(work,
+				struct smb2_lease_break_work, lease_break);
+	int rc;
+
+	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
+			      lw->lease_state);
+	cifs_dbg(FYI, "Lease release rc %d\n", rc);
+	cifs_put_tlink(lw->tlink);
+	kfree(lw);
+}
+
+static bool
+smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
+		    struct smb2_lease_break_work *lw)
+{
+	bool found;
+	__u8 lease_state;
+	struct list_head *tmp;
+	struct cifsFileInfo *cfile;
+	struct TCP_Server_Info *server = tcon->ses->server;
+	struct cifs_pending_open *open;
+	struct cifsInodeInfo *cinode;
+	int ack_req = le32_to_cpu(rsp->Flags &
+				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
+
+	lease_state = le32_to_cpu(rsp->NewLeaseState);
+
+	list_for_each(tmp, &tcon->openFileList) {
+		cfile = list_entry(tmp, struct cifsFileInfo, tlist);
+		cinode = CIFS_I(d_inode(cfile->dentry));
+
+		if (memcmp(cinode->lease_key, rsp->LeaseKey,
+							SMB2_LEASE_KEY_SIZE))
+			continue;
+
+		cifs_dbg(FYI, "found in the open list\n");
+		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
+			 le32_to_cpu(rsp->NewLeaseState));
+
+		server->ops->set_oplock_level(cinode, lease_state, 0, NULL);
+
+		if (ack_req)
+			cfile->oplock_break_cancelled = false;
+		else
+			cfile->oplock_break_cancelled = true;
+
+		queue_work(cifsiod_wq, &cfile->oplock_break);
+		kfree(lw);
+		return true;
+	}
+
+	found = false;
+	list_for_each_entry(open, &tcon->pending_opens, olist) {
+		if (memcmp(open->lease_key, rsp->LeaseKey,
+			   SMB2_LEASE_KEY_SIZE))
+			continue;
+
+		if (!found && ack_req) {
+			found = true;
+			memcpy(lw->lease_key, open->lease_key,
+			       SMB2_LEASE_KEY_SIZE);
+			lw->tlink = cifs_get_tlink(open->tlink);
+			queue_work(cifsiod_wq, &lw->lease_break);
+		}
+
+		cifs_dbg(FYI, "found in the pending open list\n");
+		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
+			 le32_to_cpu(rsp->NewLeaseState));
+
+		open->oplock = lease_state;
+	}
+	return found;
+}
+
+static bool
+smb2_is_valid_lease_break(char *buffer)
+{
+	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
+	struct list_head *tmp, *tmp1, *tmp2;
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses;
+	struct cifs_tcon *tcon;
+	struct smb2_lease_break_work *lw;
+
+	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
+	if (!lw)
+		return false;
+
+	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
+	lw->lease_state = rsp->NewLeaseState;
+
+	cifs_dbg(FYI, "Checking for lease break\n");
+
+	/* look up tcon based on tid & uid */
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each(tmp, &cifs_tcp_ses_list) {
+		server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list);
+
+		list_for_each(tmp1, &server->smb_ses_list) {
+			ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
+
+			spin_lock(&cifs_file_list_lock);
+			list_for_each(tmp2, &ses->tcon_list) {
+				tcon = list_entry(tmp2, struct cifs_tcon,
+						  tcon_list);
+				cifs_stats_inc(
+				    &tcon->stats.cifs_stats.num_oplock_brks);
+				if (smb2_tcon_has_lease(tcon, rsp, lw)) {
+					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);
+	kfree(lw);
+	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
+	return false;
+}
+
+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;
+
+	cifs_dbg(FYI, "Checking for oplock break\n");
+
+	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
+		return false;
+
+	if (rsp->StructureSize !=
+				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
+		if (le16_to_cpu(rsp->StructureSize) == 44)
+			return smb2_is_valid_lease_break(buffer);
+		else
+			return false;
+	}
+
+	cifs_dbg(FYI, "oplock level 0x%x\n", 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;
+
+				cifs_dbg(FYI, "file id match, oplock break\n");
+				cinode = CIFS_I(d_inode(cfile->dentry));
+
+				if (!CIFS_CACHE_WRITE(cinode) &&
+				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
+					cfile->oplock_break_cancelled = true;
+				else
+					cfile->oplock_break_cancelled = false;
+
+				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
+					&cinode->flags);
+
+				/*
+				 * Set flag if the server downgrades the oplock
+				 * to L2 else clear.
+				 */
+				if (rsp->OplockLevel)
+					set_bit(
+					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
+					   &cinode->flags);
+				else
+					clear_bit(
+					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
+					   &cinode->flags);
+
+				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);
+			cifs_dbg(FYI, "No matching file for oplock break\n");
+			return true;
+		}
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
+	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
+	return false;
+}