smb: client: don't break parent lease on Create

On SMB2_open_init() we have the chance to lookup for a cached
parent directory of the target file/dir, which means we can use
the it's lease key to avoid unnecessary (*) lease breaks.

(*) unnecessary because setting ParentLeaseKey is still a hint --
the server will still break the parent's lease whenever it sees fit.

Minor cleanup: remove @req arg from add_lease_context(), set
RequestedOplocklevel outside.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>

3 files changed, 46 insertions, 57 deletions

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 56bafd96cc5e..696a1d224dee 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -161,7 +161,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, const char *path,
 	struct cached_fids *cfids;
 	const char *npath;
 	int retries = 0, cur_sleep = 1;
-	__le32 lease_flags = 0;
 
 	if (cifs_sb->root == NULL)
 		return -ENOENT;
@@ -233,25 +232,6 @@ replay_again:
 			rc = -ENOENT;
 			goto out;
 		}
-		if (dentry->d_parent && server->dialect >= SMB30_PROT_ID) {
-			struct cached_fid *parent_cfid;
-
-			spin_lock(&cfids->cfid_list_lock);
-			list_for_each_entry(parent_cfid, &cfids->entries, entry) {
-				if (parent_cfid->dentry == dentry->d_parent) {
-					cifs_dbg(FYI, "found a parent cached file handle\n");
-					if (parent_cfid->has_lease && parent_cfid->time) {
-						lease_flags
-							|= SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE;
-						memcpy(pfid->parent_lease_key,
-						       parent_cfid->fid.lease_key,
-						       SMB2_LEASE_KEY_SIZE);
-					}
-					break;
-				}
-			}
-			spin_unlock(&cfids->cfid_list_lock);
-		}
 	}
 	cfid->dentry = dentry;
 	cfid->tcon = tcon;
@@ -285,7 +265,6 @@ replay_again:
 				   FILE_READ_EA,
 		.disposition = FILE_OPEN,
 		.fid = pfid,
-		.lease_flags = lease_flags,
 		.replay = !!(retries),
 	};
 
diff --git a/fs/smb/client/dir.c b/fs/smb/client/dir.c
index 1c6e5389c51f..23412156d12a 100644
--- a/fs/smb/client/dir.c
+++ b/fs/smb/client/dir.c
@@ -191,7 +191,6 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct cifs_open_parms oparms;
 	int rdwr_for_fscache = 0;
-	__le32 lease_flags = 0;
 
 	*oplock = 0;
 	if (tcon->ses->server->oplocks)
@@ -314,26 +313,6 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 		create_options |= CREATE_OPTION_READONLY;
 
 retry_open:
-	if (tcon->cfids && direntry->d_parent && server->dialect >= SMB30_PROT_ID) {
-		struct cached_fid *parent_cfid;
-
-		spin_lock(&tcon->cfids->cfid_list_lock);
-		list_for_each_entry(parent_cfid, &tcon->cfids->entries, entry) {
-			if (parent_cfid->dentry == direntry->d_parent) {
-				cifs_dbg(FYI, "found a parent cached file handle\n");
-				if (parent_cfid->has_lease && parent_cfid->time) {
-					lease_flags
-						|= SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE;
-					memcpy(fid->parent_lease_key,
-					       parent_cfid->fid.lease_key,
-					       SMB2_LEASE_KEY_SIZE);
-				}
-				break;
-			}
-		}
-		spin_unlock(&tcon->cfids->cfid_list_lock);
-	}
-
 	oparms = (struct cifs_open_parms) {
 		.tcon = tcon,
 		.cifs_sb = cifs_sb,
@@ -342,7 +321,6 @@ retry_open:
 		.disposition = disposition,
 		.path = full_path,
 		.fid = fid,
-		.lease_flags = lease_flags,
 		.mode = mode,
 	};
 	rc = server->ops->open(xid, &oparms, oplock, buf);
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 13e1362d6575..d478fc58ad70 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -2404,22 +2404,20 @@ int smb2_parse_contexts(struct TCP_Server_Info *server,
 
 static int
 add_lease_context(struct TCP_Server_Info *server,
-		  struct smb2_create_req *req,
 		  struct kvec *iov,
 		  unsigned int *num_iovec,
 		  u8 *lease_key,
-		  __u8 *oplock,
+		  __u8 oplock,
 		  u8 *parent_lease_key,
 		  __le32 flags)
 {
 	unsigned int num = *num_iovec;
 
-	iov[num].iov_base = server->ops->create_lease_buf(lease_key, *oplock,
+	iov[num].iov_base = server->ops->create_lease_buf(lease_key, oplock,
 							  parent_lease_key, flags);
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = server->vals->create_lease_size;
-	req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_LEASE;
 	*num_iovec = num + 1;
 	return 0;
 }
@@ -3077,24 +3075,58 @@ SMB2_open_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
 	iov[1].iov_len = uni_path_len;
 	iov[1].iov_base = path;
 
-	if ((!server->oplocks) || (tcon->no_lease))
+	if ((!server->oplocks) || (tcon->no_lease) || !(server->capabilities & SMB2_GLOBAL_CAP_LEASING) ||
+	    (!(server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING) &&
+	     (oparms->create_options & CREATE_NOT_FILE)))
 		*oplock = SMB2_OPLOCK_LEVEL_NONE;
 
-	if (!(server->capabilities & SMB2_GLOBAL_CAP_LEASING) ||
-	    *oplock == SMB2_OPLOCK_LEVEL_NONE)
-		req->RequestedOplockLevel = *oplock;
-	else if (!(server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING) &&
-		  (oparms->create_options & CREATE_NOT_FILE))
-		req->RequestedOplockLevel = *oplock; /* no srv lease support */
-	else {
-		rc = add_lease_context(server, req, iov, &n_iov,
-				       oparms->fid->lease_key, oplock,
+	if (*oplock != SMB2_OPLOCK_LEVEL_NONE) {
+		/*
+		 * If server has dir leases support, we can always set ParentLeaseKey -- it's only a
+		 * hint to the server that we're not modifying parent itself, only the child.
+		 *
+		 * This avoids a leasebreak of the parent dir in most cases, but the server will
+		 * still emit one when required (e.g. concurrent opens with different options/modes).
+		 */
+		memset(oparms->fid->parent_lease_key, 0, SMB2_LEASE_KEY_SIZE);
+
+		if (*oparms->path) {
+			char *tmp_path;
+			int sep = oparms->cifs_sb ? CIFS_DIR_SEP(oparms->cifs_sb) : '\\';
+
+			tmp_path = strrchr(oparms->path, sep);
+			if (tmp_path) {
+				struct cached_fid *pcfid;
+				size_t i, len = strlen(tmp_path);
+
+				tmp_path = kstrdup(oparms->path, GFP_ATOMIC);
+				if (!tmp_path)
+					return -ENOMEM;
+
+				i = strlen(oparms->path) - len;
+				memset(&tmp_path[i], 0, len);
+
+				pcfid = lookup_cached_dir(tcon->cfids, tmp_path, CFID_LOOKUP_PATH);
+				kfree(tmp_path);
+				if (pcfid) {
+					memcpy(oparms->fid->parent_lease_key, pcfid->fid.lease_key,
+					       SMB2_LEASE_KEY_SIZE);
+					oparms->lease_flags |= SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE;
+					close_cached_dir(pcfid);
+				}
+			}
+		}
+
+		rc = add_lease_context(server, iov, &n_iov,
+				       oparms->fid->lease_key, *oplock,
 				       oparms->fid->parent_lease_key,
 				       oparms->lease_flags);
 		if (rc)
 			return rc;
 	}
 
+	req->RequestedOplockLevel = *oplock;
+
 	if (*oplock == SMB2_OPLOCK_LEVEL_BATCH) {
 		rc = add_durable_context(iov, &n_iov, oparms,
 					tcon->use_persistent);