Commit b42bf888 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Implement follow_link for SMB2 



that allows to access files through symlink created on a server.

Acked-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 3ae35cde

fs/cifs/cifsglob.h

+3 −0
Original line number Diff line number Diff line
@@ -308,6 +308,9 @@ struct smb_version_operations { 
	int (*create_hardlink)(const unsigned int, struct cifs_tcon *,

			       const char *, const char *,

			       struct cifs_sb_info *);

	/* query symlink target */

	int (*query_symlink)(const unsigned int, struct cifs_tcon *,

			     const char *, char **, struct cifs_sb_info *);

	/* open a file for non-posix mounts */

	int (*open)(const unsigned int, struct cifs_open_parms *,

		    __u32 *, FILE_ALL_INFO *);

fs/cifs/inode.c

+4 −0
Original line number Diff line number Diff line
@@ -549,6 +549,10 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info, 
		 * when Unix extensions are disabled - fake it.

		 */

		fattr->cf_nlink = 2;

	} else if (fattr->cf_cifsattrs & ATTR_REPARSE) {

		fattr->cf_mode = S_IFLNK;

		fattr->cf_dtype = DT_LNK;

		fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);

	} else {

		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;

		fattr->cf_dtype = DT_REG;

fs/cifs/link.c

+5 −19
Original line number Diff line number Diff line
@@ -509,6 +509,7 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) 
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	struct tcon_link *tlink = NULL;

	struct cifs_tcon *tcon;

	struct TCP_Server_Info *server;



	xid = get_xid();
@@ -519,25 +520,7 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) 
		goto out;

	}

	tcon = tlink_tcon(tlink);



	/*

	 * For now, we just handle symlinks with unix extensions enabled.

	 * Eventually we should handle NTFS reparse points, and MacOS

	 * symlink support. For instance...

	 *

	 * rc = CIFSSMBQueryReparseLinkInfo(...)

	 *

	 * For now, just return -EACCES when the server doesn't support posix

	 * extensions. Note that we still allow querying symlinks when posix

	 * extensions are manually disabled. We could disable these as well

	 * but there doesn't seem to be any harm in allowing the client to

	 * read them.

	 */

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&

	    !cap_unix(tcon->ses)) {

		rc = -EACCES;

		goto out;

	}

	server = tcon->ses->server;



	full_path = build_path_from_dentry(direntry);

	if (!full_path)
@@ -559,6 +542,9 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) 
	if ((rc != 0) && cap_unix(tcon->ses))

		rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,

					     cifs_sb->local_nls);

	else if (rc != 0 && server->ops->query_symlink)

		rc = server->ops->query_symlink(xid, tcon, full_path,

						&target_path, cifs_sb);



	kfree(full_path);

out:

fs/cifs/readdir.c

+3 −0
Original line number Diff line number Diff line
@@ -172,6 +172,9 @@ cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb) 
		if (cifs_dfs_is_possible(cifs_sb) &&

		    (fattr->cf_cifsattrs & ATTR_REPARSE))

			fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;

	} else if (fattr->cf_cifsattrs & ATTR_REPARSE) {

		fattr->cf_mode = S_IFLNK;

		fattr->cf_dtype = DT_LNK;

	} else {

		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;

		fattr->cf_dtype = DT_REG;

fs/cifs/smb2file.c

+1 −1
Original line number Diff line number Diff line
@@ -86,7 +86,7 @@ smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, 
	if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)

		memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);



	rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data);

	rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);

	if (rc)

		goto out;