[PATCH 1/9] smb/client: factor out cifs_new_dir_fileinfo()

[ChenXiaoSong <chenxiaosong@chenxiaosong.com>]

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

This patch was split out to make it easier to review.

Both readdir and notify can need directory private data before a
search handle exists. Move the common cifsFileInfo allocation and
initialization into a helper so those paths share the same setup.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 fs/smb/client/cifsproto.h |  2 ++
 fs/smb/client/file.c      | 24 ++++++++++++++++++++++++
 fs/smb/client/readdir.c   | 14 ++++++--------
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index c4ababcb51a3..dfbad6bc0a9b 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -267,6 +267,8 @@ void cifs_close_all_deferred_files(struct cifs_tcon *tcon);
 void cifs_close_all_deferred_files_sb(struct cifs_sb_info *cifs_sb);
 void cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon,
 					   struct dentry *dentry);
+struct cifsFileInfo *cifs_new_dir_fileinfo(struct file *file,
+					   struct tcon_link *tlink);
 
 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
 					     const char *path);
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 8b25d6c9ec5e..f1e854f381d9 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -660,6 +660,30 @@ cifs_down_write(struct rw_semaphore *sem)
 static void cifsFileInfo_put_work(struct work_struct *work);
 void serverclose_work(struct work_struct *work);
 
+struct cifsFileInfo *cifs_new_dir_fileinfo(struct file *file,
+					   struct tcon_link *tlink)
+{
+	struct cifsFileInfo *cfile, *old;
+
+	cfile = kzalloc_obj(struct cifsFileInfo);
+	if (!cfile)
+		return NULL;
+
+	spin_lock_init(&cfile->file_info_lock);
+	mutex_init(&cfile->fh_mutex);
+	cfile->invalidHandle = true;
+	cfile->tlink = cifs_get_tlink(tlink);
+
+	old = cmpxchg(&file->private_data, NULL, cfile);
+	if (old) {
+		cifs_put_tlink(cfile->tlink);
+		kfree(cfile);
+		return old;
+	}
+
+	return cfile;
+}
+
 struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 				       struct tcon_link *tlink, __u32 oplock,
 				       const char *symlink_target)
diff --git a/fs/smb/client/readdir.c b/fs/smb/client/readdir.c
index a50c86bbe60f..f108e719e683 100644
--- a/fs/smb/client/readdir.c
+++ b/fs/smb/client/readdir.c
@@ -355,20 +355,17 @@ _initiate_cifs_search(const unsigned int xid, struct file *file,
 	__u16 search_flags;
 	int rc = 0;
 
-	if (file->private_data == NULL) {
+	if (!file->private_data) {
 		tlink = cifs_sb_tlink(cifs_sb);
 		if (IS_ERR(tlink))
 			return PTR_ERR(tlink);
 
-		cifsFile = kzalloc_obj(struct cifsFileInfo);
-		if (cifsFile == NULL) {
+		cifsFile = cifs_new_dir_fileinfo(file, tlink);
+		if (!cifsFile) {
 			rc = -ENOMEM;
 			goto error_exit;
 		}
-		spin_lock_init(&cifsFile->file_info_lock);
-		file->private_data = cifsFile;
-		cifsFile->tlink = cifs_get_tlink(tlink);
-		tcon = tlink_tcon(tlink);
+		tcon = tlink_tcon(cifsFile->tlink);
 	} else {
 		cifsFile = file->private_data;
 		tcon = tlink_tcon(cifsFile->tlink);
@@ -1125,7 +1122,8 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
 	 * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 	 * '..'. Otherwise we won't be able to notify VFS in case of failure.
 	 */
-	if (file->private_data == NULL) {
+	cifsFile = file->private_data;
+	if (!cifsFile || cifsFile->invalidHandle) {
 		rc = initiate_cifs_search(xid, file, full_path);
 		cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 		if (rc)
-- 
2.54.0