kernel-fxtec-pro1x/fs/cifs/cifs_fs_sb.h
Jeff Layton d7c86ff8cd cifs: don't use vfsmount to pin superblock for oplock breaks
Filesystems aren't really supposed to do anything with a vfsmount. It's
considered a layering violation since vfsmounts are entirely managed at
the VFS layer.

CIFS currently keeps an active reference to a vfsmount in order to
prevent the superblock vanishing before an oplock break has completed.
What we really want to do instead is to keep sb->s_active high until the
oplock break has completed. This patch borrows the scheme that NFS uses
for handling sillyrenames.

An atomic_t is added to the cifs_sb_info. When it transitions from 0 to
1, an extra reference to the superblock is taken (by bumping the
s_active value). When it transitions from 1 to 0, that reference is
dropped and a the superblock teardown may proceed if there are no more
references to it.

Also, the vfsmount pointer is removed from cifsFileInfo and from
cifs_new_fileinfo, and some bogus forward declarations are removed from
cifsfs.h.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-12 18:08:01 +00:00

65 lines
2.8 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/radix-tree.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 */
struct cifs_sb_info {
struct radix_tree_root tlink_tree;
#define CIFS_TLINK_MASTER_TAG 0 /* is "master" (mount) tcon */
spinlock_t tlink_tree_lock;
struct nls_table *local_nls;
unsigned int rsize;
unsigned int wsize;
atomic_t active;
uid_t mnt_uid;
gid_t mnt_gid;
mode_t mnt_file_mode;
mode_t mnt_dir_mode;
unsigned int mnt_cifs_flags;
int prepathlen;
char *prepath; /* relative path under the share to mount to */
#ifdef CONFIG_CIFS_DFS_UPCALL
char *mountdata; /* mount options received at mount time */
#endif
struct backing_dev_info bdi;
struct delayed_work prune_tlinks;
};
#endif /* _CIFS_FS_SB_H */