CIFS: Request SMB2.1 leases

if server supports them and we need oplocks.

Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsfs.c

@@ -36,6 +36,7 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/namei.h>
+#include <linux/random.h>
 #include <net/ipv6.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -88,6 +89,10 @@ extern mempool_t *cifs_mid_poolp;
 
 struct workqueue_struct	*cifsiod_wq;
 
+#ifdef CONFIG_CIFS_SMB2
+__u8 cifs_client_guid[SMB2_CLIENT_GUID_SIZE];
+#endif
+
 static int
 cifs_read_super(struct super_block *sb)
 {
@@ -218,20 +223,25 @@ cifs_alloc_inode(struct super_block *sb)
 		return NULL;
 	cifs_inode->cifsAttrs = 0x20;	/* default */
 	cifs_inode->time = 0;
-	/* Until the file is open and we have gotten oplock
-	info back from the server, can not assume caching of
-	file data or metadata */
+	/*
+	 * Until the file is open and we have gotten oplock info back from the
+	 * server, can not assume caching of file data or metadata.
+	 */
 	cifs_set_oplock_level(cifs_inode, 0);
 	cifs_inode->delete_pending = false;
 	cifs_inode->invalid_mapping = false;
 	cifs_inode->vfs_inode.i_blkbits = 14;  /* 2**14 = CIFS_MAX_MSGSIZE */
 	cifs_inode->server_eof = 0;
 	cifs_inode->uniqueid = 0;
 	cifs_inode->createtime = 0;
-
-	/* Can not set i_flags here - they get immediately overwritten
-	   to zero by the VFS */
-/*	cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME;*/
+#ifdef CONFIG_CIFS_SMB2
+	get_random_bytes(cifs_inode->lease_key, SMB2_LEASE_KEY_SIZE);
+#endif
+	/*
+	 * Can not set i_flags here - they get immediately overwritten to zero
+	 * by the VFS.
+	 */
+	/* cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME; */
 	INIT_LIST_HEAD(&cifs_inode->openFileList);
 	INIT_LIST_HEAD(&cifs_inode->llist);
 	return &cifs_inode->vfs_inode;
@@ -1107,6 +1117,10 @@ init_cifs(void)
 	spin_lock_init(&cifs_file_list_lock);
 	spin_lock_init(&GlobalMid_Lock);
 
+#ifdef CONFIG_CIFS_SMB2
+	get_random_bytes(cifs_client_guid, SMB2_CLIENT_GUID_SIZE);
+#endif
+
 	if (cifs_max_pending < 2) {
 		cifs_max_pending = 2;
 		cFYI(1, "cifs_max_pending set to min of 2");

fs/cifs/cifsglob.h

@@ -361,6 +361,12 @@ struct smb_version_operations {
 				 const unsigned int);
 	/* push brlocks from the cache to the server */
 	int (*push_mand_locks)(struct cifsFileInfo *);
+	/* get lease key of the inode */
+	void (*get_lease_key)(struct inode *, struct cifs_fid *fid);
+	/* set lease key of the inode */
+	void (*set_lease_key)(struct inode *, struct cifs_fid *fid);
+	/* generate new lease key */
+	void (*new_lease_key)(struct cifs_fid *fid);
 };
 
 struct smb_version_values {
@@ -895,6 +901,7 @@ struct cifs_fid {
 #ifdef CONFIG_CIFS_SMB2
 	__u64 persistent_fid;	/* persist file id for smb2 */
 	__u64 volatile_fid;	/* volatile file id for smb2 */
+	__u8 lease_key[SMB2_LEASE_KEY_SIZE];	/* lease key for smb2 */
 #endif
 };
 
@@ -1012,6 +1019,9 @@ struct cifsInodeInfo {
 	u64  server_eof;		/* current file size on server -- protected by i_lock */
 	u64  uniqueid;			/* server inode number */
 	u64  createtime;		/* creation time on server */
+#ifdef CONFIG_CIFS_SMB2
+	__u8 lease_key[SMB2_LEASE_KEY_SIZE];	/* lease key for this inode */
+#endif
 #ifdef CONFIG_CIFS_FSCACHE
 	struct fscache_cookie *fscache;
 #endif

fs/cifs/dir.c

@@ -340,6 +340,8 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
 					 xid, &fid->netfid);
 		if (newinode) {
+			if (server->ops->set_lease_key)
+				server->ops->set_lease_key(newinode, fid);
 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 				newinode->i_mode = mode;
 			if ((*oplock & CIFS_CREATE_ACTION) &&
@@ -418,6 +420,9 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 	tcon = tlink_tcon(tlink);
 	server = tcon->ses->server;
 
+	if (server->ops->new_lease_key)
+		server->ops->new_lease_key(&fid);
+
 	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 			    &oplock, &fid, opened);
 
@@ -473,10 +478,14 @@ int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 	if (IS_ERR(tlink))
 		goto out_free_xid;
 
-	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
-			    &oplock, &fid, &created);
 	tcon = tlink_tcon(tlink);
 	server = tcon->ses->server;
+
+	if (server->ops->new_lease_key)
+		server->ops->new_lease_key(&fid);
+
+	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
+			    &oplock, &fid, &created);
 	if (!rc && server->ops->close)
 		server->ops->close(xid, tcon, &fid);
 

fs/cifs/file.c

@@ -177,8 +177,9 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 	int disposition;
 	int create_options = CREATE_NOT_DIR;
 	FILE_ALL_INFO *buf;
+	struct TCP_Server_Info *server = tcon->ses->server;
 
-	if (!tcon->ses->server->ops->open)
+	if (!server->ops->open)
 		return -ENOSYS;
 
 	desired_access = cifs_convert_flags(f_flags);
@@ -218,9 +219,9 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 	if (backup_cred(cifs_sb))
 		create_options |= CREATE_OPEN_BACKUP_INTENT;
 
-	rc = tcon->ses->server->ops->open(xid, tcon, full_path, disposition,
-					  desired_access, create_options, fid,
-					  oplock, buf, cifs_sb);
+	rc = server->ops->open(xid, tcon, full_path, disposition,
+			       desired_access, create_options, fid, oplock, buf,
+			       cifs_sb);
 
 	if (rc)
 		goto out;
@@ -372,6 +373,7 @@ int cifs_open(struct inode *inode, struct file *file)
 	unsigned int xid;
 	__u32 oplock;
 	struct cifs_sb_info *cifs_sb;
+	struct TCP_Server_Info *server;
 	struct cifs_tcon *tcon;
 	struct tcon_link *tlink;
 	struct cifsFileInfo *cfile = NULL;
@@ -388,6 +390,7 @@ int cifs_open(struct inode *inode, struct file *file)
 		return PTR_ERR(tlink);
 	}
 	tcon = tlink_tcon(tlink);
+	server = tcon->ses->server;
 
 	full_path = build_path_from_dentry(file->f_path.dentry);
 	if (full_path == NULL) {
@@ -432,6 +435,9 @@ int cifs_open(struct inode *inode, struct file *file)
 	}
 
 	if (!posix_open_ok) {
+		if (server->ops->get_lease_key)
+			server->ops->get_lease_key(inode, &fid);
+
 		rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 				  file->f_flags, &oplock, &fid, xid);
 		if (rc)
@@ -440,8 +446,8 @@ int cifs_open(struct inode *inode, struct file *file)
 
 	cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 	if (cfile == NULL) {
-		if (tcon->ses->server->ops->close)
-			tcon->ses->server->ops->close(xid, tcon, &fid);
+		if (server->ops->close)
+			server->ops->close(xid, tcon, &fid);
 		rc = -ENOMEM;
 		goto out;
 	}
@@ -567,6 +573,9 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 	if (backup_cred(cifs_sb))
 		create_options |= CREATE_OPEN_BACKUP_INTENT;
 
+	if (server->ops->get_lease_key)
+		server->ops->get_lease_key(inode, &fid);
+
 	/*
 	 * Can not refresh inode by passing in file_info buf to be returned by
 	 * CIFSSMBOpen and then calling get_inode_info with returned buf since

fs/cifs/smb2file.c

@@ -63,6 +63,7 @@ smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path,
 	int rc;
 	__le16 *smb2_path;
 	struct smb2_file_all_info *smb2_data = NULL;
+	__u8 smb2_oplock[17];
 
 	smb2_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (smb2_path == NULL) {
@@ -78,11 +79,14 @@ smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path,
 	}
 
 	desired_access |= FILE_READ_ATTRIBUTES;
-	*oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
+	*smb2_oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
+
+	if (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
+		memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
 
 	rc = SMB2_open(xid, tcon, smb2_path, &fid->persistent_fid,
 		       &fid->volatile_fid, desired_access, disposition,
-		       0, 0, (__u8 *)oplock, smb2_data);
+		       0, 0, smb2_oplock, smb2_data);
 	if (rc)
 		goto out;
 
@@ -99,6 +103,7 @@ smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path,
 		move_smb2_info_to_cifs(buf, smb2_data);
 	}
 
+	*oplock = *smb2_oplock;
 out:
 	kfree(smb2_data);
 	kfree(smb2_path);

fs/cifs/smb2ops.c

@@ -555,6 +555,24 @@ smb2_mand_lock(const unsigned int xid, struct cifsFileInfo *cfile, __u64 offset,
 			 current->tgid, length, offset, type, wait);
 }
 
+static void
+smb2_get_lease_key(struct inode *inode, struct cifs_fid *fid)
+{
+	memcpy(fid->lease_key, CIFS_I(inode)->lease_key, SMB2_LEASE_KEY_SIZE);
+}
+
+static void
+smb2_set_lease_key(struct inode *inode, struct cifs_fid *fid)
+{
+	memcpy(CIFS_I(inode)->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
+}
+
+static void
+smb2_new_lease_key(struct cifs_fid *fid)
+{
+	get_random_bytes(fid->lease_key, SMB2_LEASE_KEY_SIZE);
+}
+
 struct smb_version_operations smb21_operations = {
 	.compare_fids = smb2_compare_fids,
 	.setup_request = smb2_setup_request,
@@ -616,6 +634,9 @@ struct smb_version_operations smb21_operations = {
 	.mand_lock = smb2_mand_lock,
 	.mand_unlock_range = smb2_unlock_range,
 	.push_mand_locks = smb2_push_mandatory_locks,
+	.get_lease_key = smb2_get_lease_key,
+	.set_lease_key = smb2_set_lease_key,
+	.new_lease_key = smb2_new_lease_key,
 };
 
 struct smb_version_values smb21_values = {