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linux-next/fs/cifs/cifs_fs_sb.h
Steve French 3d4ef9a153 smb3: fix redundant opens on root
In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share
over and over again in various places during mount and path revalidation
and also in statfs.  This patch cuts redundant traffic (opens and closes)
by simply keeping the directory handle for the root around (and reopening
it as needed on reconnect), so query calls don't require three round
trips to copmlete - just one, and eases load on network, client and
server (on mount alone, cuts network traffic by more than a third).

Also add a new cifs mount parm "nohandlecache" to allow users whose
servers might have resource constraints (eg in case they have a server
with so many users connecting to it that this extra handle per mount
could possibly be a resource concern).

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27 17:56:35 -05:00

77 lines
3.4 KiB
C

/*
* fs/cifs/cifs_fs_sb.h
*
* Copyright (c) International Business Machines Corp., 2002,2004
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
*/
#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 */
struct cifs_sb_info {
struct rb_root tlink_tree;
spinlock_t tlink_tree_lock;
struct tcon_link *master_tlink;
struct nls_table *local_nls;
unsigned int rsize;
unsigned int wsize;
unsigned long actimeo; /* attribute cache timeout (jiffies) */
atomic_t active;
kuid_t mnt_uid;
kgid_t mnt_gid;
kuid_t mnt_backupuid;
kgid_t mnt_backupgid;
umode_t mnt_file_mode;
umode_t mnt_dir_mode;
unsigned int mnt_cifs_flags;
char *mountdata; /* options received at mount time or via DFS refs */
struct delayed_work prune_tlinks;
struct rcu_head rcu;
char *prepath;
};
#endif /* _CIFS_FS_SB_H */