From 3eb40512530e4f64f819d8e723b6f41695dace5a Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Sat, 5 Oct 2024 16:02:55 +0200 Subject: cifs: Improve creating native symlinks pointing to directory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SMB protocol for native symlinks distinguish between symlink to directory and symlink to file. These two symlink types cannot be exchanged, which means that symlink of file type pointing to directory cannot be resolved at all (and vice-versa). Windows follows this rule for local filesystems (NTFS) and also for SMB. Linux SMB client currenly creates all native symlinks of file type. Which means that Windows (and some other SMB clients) cannot resolve symlinks pointing to directory created by Linux SMB client. As Linux system does not distinguish between directory and file symlinks, its API does not provide enough information for Linux SMB client during creating of native symlinks. Add some heuristic into the Linux SMB client for choosing the correct symlink type during symlink creation. Check if the symlink target location ends with slash, or last path component is dot or dot-dot, and check if the target location on SMB share exists and is a directory. If at least one condition is truth then create a new SMB symlink of directory type. Otherwise create it as file type symlink. This change improves interoperability with Windows systems. Windows systems would be able to resolve more SMB symlinks created by Linux SMB client which points to existing directory. Signed-off-by: Pali Rohár Signed-off-by: Steve French --- fs/smb/client/smb2inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/smb/client/smb2inode.c') diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c index 4e9e225520a6..e49d0c25eb03 100644 --- a/fs/smb/client/smb2inode.c +++ b/fs/smb/client/smb2inode.c @@ -1198,6 +1198,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, const unsigned int xid, struct cifs_tcon *tcon, const char *full_path, + bool directory, struct kvec *reparse_iov, struct kvec *xattr_iov) { @@ -1217,7 +1218,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, FILE_READ_ATTRIBUTES | FILE_WRITE_ATTRIBUTES, FILE_CREATE, - CREATE_NOT_DIR | OPEN_REPARSE_POINT, + (directory ? CREATE_NOT_FILE : CREATE_NOT_DIR) | OPEN_REPARSE_POINT, ACL_NO_MODE); if (xattr_iov) oparms.ea_cctx = xattr_iov; -- cgit