linux/fs/cifs/cifs_fs_sb.h
Paulo Alcantara c88f7dcd6d cifs: support nested dfs links over reconnect
Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.

Make the following case work:

* mount //root/dfs/link /mnt -o ...
  - final share: /server/share

* in server settings
  - change target folder of /root/dfs/link3 to /server/share2
  - change target folder of /root/dfs/link2 to /root/dfs/link3
  - change target folder of /root/dfs/link to /root/dfs/link2

* mount -o remount,... /mnt
 - refresh all dfs referrals
 - mark current connection for failover
 - cifs_reconnect() reconnects to root server
 - tree_connect()
   * checks that /root/dfs/link2 is a link, then chase it
   * checks that root/dfs/link3 is a link, then chase it
   * finally tree connect to /server/share2

If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).

Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-10 16:30:13 -06:00

77 lines
3.4 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 */
/*
*
* Copyright (c) International Business Machines Corp., 2002,2004
* Author(s): Steve French (sfrench@us.ibm.com)
*
*/
#include <linux/rbtree.h>
#ifndef _CIFS_FS_SB_H
#define _CIFS_FS_SB_H
#include <linux/backing-dev.h>
#define CIFS_MOUNT_NO_PERM 1 /* do not do client vfs_perm check */
#define CIFS_MOUNT_SET_UID 2 /* set current's euid in create etc. */
#define CIFS_MOUNT_SERVER_INUM 4 /* inode numbers from uniqueid from server */
#define CIFS_MOUNT_DIRECT_IO 8 /* do not write nor read through page cache */
#define CIFS_MOUNT_NO_XATTR 0x10 /* if set - disable xattr support */
#define CIFS_MOUNT_MAP_SPECIAL_CHR 0x20 /* remap illegal chars in filenames */
#define CIFS_MOUNT_POSIX_PATHS 0x40 /* Negotiate posix pathnames if possible*/
#define CIFS_MOUNT_UNX_EMUL 0x80 /* Network compat with SFUnix emulation */
#define CIFS_MOUNT_NO_BRL 0x100 /* No sending byte range locks to srv */
#define CIFS_MOUNT_CIFS_ACL 0x200 /* send ACL requests to non-POSIX srv */
#define CIFS_MOUNT_OVERR_UID 0x400 /* override uid returned from server */
#define CIFS_MOUNT_OVERR_GID 0x800 /* override gid returned from server */
#define CIFS_MOUNT_DYNPERM 0x1000 /* allow in-memory only mode setting */
#define CIFS_MOUNT_NOPOSIXBRL 0x2000 /* mandatory not posix byte range lock */
#define CIFS_MOUNT_NOSSYNC 0x4000 /* don't do slow SMBflush on every sync*/
#define CIFS_MOUNT_FSCACHE 0x8000 /* local caching enabled */
#define CIFS_MOUNT_MF_SYMLINKS 0x10000 /* Minshall+French Symlinks enabled */
#define CIFS_MOUNT_MULTIUSER 0x20000 /* multiuser mount */
#define CIFS_MOUNT_STRICT_IO 0x40000 /* strict cache mode */
#define CIFS_MOUNT_RWPIDFORWARD 0x80000 /* use pid forwarding for rw */
#define CIFS_MOUNT_POSIXACL 0x100000 /* mirror of SB_POSIXACL in mnt_cifs_flags */
#define CIFS_MOUNT_CIFS_BACKUPUID 0x200000 /* backup intent bit for a user */
#define CIFS_MOUNT_CIFS_BACKUPGID 0x400000 /* backup intent bit for a group */
#define CIFS_MOUNT_MAP_SFM_CHR 0x800000 /* SFM/MAC mapping for illegal chars */
#define CIFS_MOUNT_USE_PREFIX_PATH 0x1000000 /* make subpath with unaccessible
* root mountable
*/
#define CIFS_MOUNT_UID_FROM_ACL 0x2000000 /* try to get UID via special SID */
#define CIFS_MOUNT_NO_HANDLE_CACHE 0x4000000 /* disable caching dir handles */
#define CIFS_MOUNT_NO_DFS 0x8000000 /* disable DFS resolving */
#define CIFS_MOUNT_MODE_FROM_SID 0x10000000 /* retrieve mode from special ACE */
#define CIFS_MOUNT_RO_CACHE 0x20000000 /* assumes share will not change */
#define CIFS_MOUNT_RW_CACHE 0x40000000 /* assumes only client accessing */
#define CIFS_MOUNT_SHUTDOWN 0x80000000
struct cifs_sb_info {
struct rb_root tlink_tree;
spinlock_t tlink_tree_lock;
struct tcon_link *master_tlink;
struct nls_table *local_nls;
struct smb3_fs_context *ctx;
atomic_t active;
unsigned int mnt_cifs_flags;
struct delayed_work prune_tlinks;
struct rcu_head rcu;
/* only used when CIFS_MOUNT_USE_PREFIX_PATH is set */
char *prepath;
/* randomly generated 128-bit number for indexing dfs mount groups in referral cache */
uuid_t dfs_mount_id;
/*
* Indicate whether serverino option was turned off later
* (cifs_autodisable_serverino) in order to match new mounts.
*/
bool mnt_cifs_serverino_autodisabled;
/*
* Available once the mount has completed.
*/
struct dentry *root;
};
#endif /* _CIFS_FS_SB_H */