cifsfs.c

Linux内核自带的cifs模块

/*
 *   fs/cifs/cifsfs.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2007
 *   Author(s): Steve French ([e-mail])
 *
 *   Common Internet FileSystem (CIFS) client
 *
 *   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.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* Note that BB means BUGBUG (ie something to fix eventually) */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/vfs.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include "cifsfs.h"
#include "cifspdu.h"
#define DECLARE_GLOBALS_HERE
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include <linux/mm.h>
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,9)
#include <linux/moduleparam.h>
#endif /* 2.6.9 */
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,19)
#include <linux/freezer.h>
#endif /* 2.6.19 */
#define CIFS_MAGIC_NUMBER 0xFF534D42	/* the first four bytes of SMB PDUs */

#ifdef CONFIG_CIFS_QUOTA
static struct quotactl_ops cifs_quotactl_ops;
#endif /* QUOTA */

#ifdef CONFIG_CIFS_EXPERIMENTAL
extern struct export_operations cifs_export_ops;
#endif /* EXPERIMENTAL */

int cifsFYI = 0;
int cifsERROR = 1;
int traceSMB = 0;
unsigned int oplockEnabled = 1;
unsigned int experimEnabled = 0;
unsigned int linuxExtEnabled = 1;
unsigned int lookupCacheEnabled = 1;
unsigned int multiuser_mount = 0;
unsigned int extended_security = CIFSSEC_DEF;
/* unsigned int ntlmv2_support = 0; */
unsigned int sign_CIFS_PDUs = 1;
extern struct task_struct *oplockThread; /* remove sparse warning */
struct task_struct *oplockThread = NULL;
/* extern struct task_struct * dnotifyThread; remove sparse warning */
static struct task_struct *dnotifyThread = NULL;
static const struct super_operations cifs_super_ops;
unsigned int CIFSMaxBufSize = CIFS_MAX_MSGSIZE;
module_param(CIFSMaxBufSize, int, 0);
MODULE_PARM_DESC(CIFSMaxBufSize, "Network buffer size (not including header). "
				 "Default: 16384 Range: 8192 to 130048");
unsigned int cifs_min_rcv = CIFS_MIN_RCV_POOL;
module_param(cifs_min_rcv, int, 0);
MODULE_PARM_DESC(cifs_min_rcv, "Network buffers in pool. Default: 4 Range: "
				"1 to 64");
unsigned int cifs_min_small = 30;
module_param(cifs_min_small, int, 0);
MODULE_PARM_DESC(cifs_min_small, "Small network buffers in pool. Default: 30 "
				 "Range: 2 to 256");
unsigned int cifs_max_pending = CIFS_MAX_REQ;
module_param(cifs_max_pending, int, 0);
MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server. "
				   "Default: 50 Range: 2 to 256");

extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;

extern struct kmem_cache *cifs_oplock_cachep;

static int
cifs_read_super(struct super_block *sb, void *data,
		const char *devname, int silent)
{
	struct inode *inode;
	struct cifs_sb_info *cifs_sb;
	int rc = 0;

	/* BB should we make this contingent on mount parm? */
	sb->s_flags |= MS_NODIRATIME | MS_NOATIME;
	sb->s_fs_info = kzalloc(sizeof(struct cifs_sb_info), GFP_KERNEL);
	cifs_sb = CIFS_SB(sb);
	if (cifs_sb == NULL)
		return -ENOMEM;

	rc = cifs_mount(sb, cifs_sb, data, devname);

	if (rc) {
		if (!silent)
			cERROR(1,
			       ("cifs_mount failed w/return code = %d", rc));
		goto out_mount_failed;
	}

	sb->s_magic = CIFS_MAGIC_NUMBER;
	sb->s_op = &cifs_super_ops;
/*	if (cifs_sb->tcon->ses->server->maxBuf > MAX_CIFS_HDR_SIZE + 512)
	    sb->s_blocksize =
		cifs_sb->tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE; */
#ifdef CONFIG_CIFS_QUOTA
	sb->s_qcop = &cifs_quotactl_ops;
#endif
	sb->s_blocksize = CIFS_MAX_MSGSIZE;
	sb->s_blocksize_bits = 14;	/* default 2**14 = CIFS_MAX_MSGSIZE */
	inode = iget(sb, ROOT_I);

	if (!inode) {
		rc = -ENOMEM;
		goto out_no_root;
	}

	sb->s_root = d_alloc_root(inode);

	if (!sb->s_root) {
		rc = -ENOMEM;
		goto out_no_root;
	}

#ifdef CONFIG_CIFS_EXPERIMENTAL
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
		cFYI(1, ("export ops supported"));
		sb->s_export_op = &cifs_export_ops;
	}
#endif /* EXPERIMENTAL */

	return 0;

out_no_root:
	cERROR(1, ("cifs_read_super: get root inode failed"));
	if (inode)
		iput(inode);

out_mount_failed:
	if (cifs_sb) {
		if (cifs_sb->local_nls)
			unload_nls(cifs_sb->local_nls);
		kfree(cifs_sb);
	}
	return rc;
}

static void
cifs_put_super(struct super_block *sb)
{
	int rc = 0;
	struct cifs_sb_info *cifs_sb;

	cFYI(1, ("In cifs_put_super"));
	cifs_sb = CIFS_SB(sb);
	if (cifs_sb == NULL) {
		cFYI(1, ("Empty cifs superblock info passed to unmount"));
		return;
	}
	rc = cifs_umount(sb, cifs_sb);
	if (rc) {
		cERROR(1, ("cifs_umount failed with return code %d", rc));
	}
	unload_nls(cifs_sb->local_nls);
	kfree(cifs_sb);
	return;
}

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 15)
void * kzalloc(size_t size, unsigned flgs)
{
	void * buf;
	buf = kmalloc(size, flgs);
	if(buf != NULL)
		memset(buf, 0, size);
	return buf;
}
#endif

#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17)
static int
cifs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
#else
static inline mempool_t *
mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
{
        return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
                              (void *) kc);
}

static int
cifs_statfs(struct super_block *sb, struct kstatfs *buf)
{
#endif	
	int xid;
	int rc = -EOPNOTSUPP;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	cifs_sb = CIFS_SB(sb);
	pTcon = cifs_sb->tcon;

	buf->f_type = CIFS_MAGIC_NUMBER;

	/* instead could get the real value via SMB_QUERY_FS_ATTRIBUTE_INFO */
	buf->f_namelen = PATH_MAX; /* PATH_MAX may be too long - it would
				      presumably be total path, but note
				      that some servers (includinng Samba 3)
				      have a shorter maximum path */
	buf->f_files = 0;	/* undefined */
	buf->f_ffree = 0;	/* unlimited */

/* BB we could add a second check for a QFS Unix capability bit */
/* BB FIXME check CIFS_POSIX_EXTENSIONS Unix cap first FIXME BB */
    if ((pTcon->ses->capabilities & CAP_UNIX) && (CIFS_POSIX_EXTENSIONS &
			le64_to_cpu(pTcon->fsUnixInfo.Capability)))
	    rc = CIFSSMBQFSPosixInfo(xid, pTcon, buf);

    /* Only need to call the old QFSInfo if failed
    on newer one */
    if (rc)
	if (pTcon->ses->capabilities & CAP_NT_SMBS)
		rc = CIFSSMBQFSInfo(xid, pTcon, buf); /* not supported by OS2 */

	/* Some old Windows servers also do not support level 103, retry with
	   older level one if old server failed the previous call or we
	   bypassed it because we detected that this was an older LANMAN sess */
	if (rc)
		rc = SMBOldQFSInfo(xid, pTcon, buf);
	/* int f_type;
	   __fsid_t f_fsid;
	   int f_namelen;  */
	/* BB get from info in tcon struct at mount time call to QFSAttrInfo */
	FreeXid(xid);
	return 0;		/* always return success? what if volume is no
				   longer available? */
}

static int cifs_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	struct cifs_sb_info *cifs_sb;

	cifs_sb = CIFS_SB(inode->i_sb);

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
		return 0;
	else /* file mode might have been restricted at mount time
		on the client (above and beyond ACL on servers) for
		servers which do not support setting and viewing mode bits,
		so allowing client to check permissions is useful */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,10) 
		return vfs_permission(inode, mask);
#else
		return generic_permission(inode, mask, NULL);
#endif
}

static struct kmem_cache *cifs_inode_cachep;
static struct kmem_cache *cifs_req_cachep;
static struct kmem_cache *cifs_mid_cachep;
struct kmem_cache *cifs_oplock_cachep;
static struct kmem_cache *cifs_sm_req_cachep;
mempool_t *cifs_sm_req_poolp;
mempool_t *cifs_req_poolp;
mempool_t *cifs_mid_poolp;

static struct inode *
cifs_alloc_inode(struct super_block *sb)
{
	struct cifsInodeInfo *cifs_inode;
	cifs_inode = kmem_cache_alloc(cifs_inode_cachep, GFP_KERNEL);
	if (!cifs_inode)
		return NULL;
	cifs_inode->cifsAttrs = 0x20;	/* default */
	atomic_set(&cifs_inode->inUse, 0);
	cifs_inode->time = 0;
	/* Until the file is open and we have gotten oplock
	info back from the server, can not assume caching of
	file data or metadata */
	cifs_inode->clientCanCacheRead = FALSE;
	cifs_inode->clientCanCacheAll = FALSE;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
	cifs_inode->vfs_inode.i_blksize = CIFS_MAX_MSGSIZE;
#endif
	cifs_inode->vfs_inode.i_blkbits = 14;  /* 2**14 = CIFS_MAX_MSGSIZE */

	/* Can not set i_flags here - they get immediately overwritten
	   to zero by the VFS */
/*	cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME;*/
	INIT_LIST_HEAD(&cifs_inode->openFileList);
	return &cifs_inode->vfs_inode;
}

static void
cifs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
}

/*
 * cifs_show_options() is for displaying mount options in /proc/mounts.
 * Not all settable options are displayed but most of the important
 * ones are.
 */
static int
cifs_show_options(struct seq_file *s, struct vfsmount *m)
{
	struct cifs_sb_info *cifs_sb;

	cifs_sb = CIFS_SB(m->mnt_sb);

	if (cifs_sb) {
		if (cifs_sb->tcon) {
/* BB add prepath to mount options displayed */
			seq_printf(s, ",unc=%s", cifs_sb->tcon->treeName);
			if (cifs_sb->tcon->ses) {
				if (cifs_sb->tcon->ses->userName)
					seq_printf(s, ",username=%s",
					   cifs_sb->tcon->ses->userName);
				if (cifs_sb->tcon->ses->domainName)
					seq_printf(s, ",domain=%s",
					   cifs_sb->tcon->ses->domainName);
			}
		}
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
			seq_printf(s, ",posixpaths");
		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID) ||
		   !(cifs_sb->tcon->unix_ext))
			seq_printf(s, ",uid=%d", cifs_sb->mnt_uid);
		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID) ||
		   !(cifs_sb->tcon->unix_ext))
			seq_printf(s, ",gid=%d", cifs_sb->mnt_gid);
		seq_printf(s, ",rsize=%d", cifs_sb->rsize);
		seq_printf(s, ",wsize=%d", cifs_sb->wsize);
	}
	return 0;
}

#ifdef CONFIG_CIFS_QUOTA
int cifs_xquota_set(struct super_block *sb, int quota_type, qid_t qid,
		struct fs_disk_quota *pdquota)
{
	int xid;
	int rc = 0;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *pTcon;

	if (cifs_sb)
		pTcon = cifs_sb->tcon;
	else
		return -EIO;


	xid = GetXid();
	if (pTcon) {
		cFYI(1, ("set type: 0x%x id: %d", quota_type, qid));
	} else {
		rc = -EIO;
	}

	FreeXid(xid);
	return rc;
}

int cifs_xquota_get(struct super_block *sb, int quota_type, qid_t qid,
		    struct fs_disk_quota *pdquota)
{
	int xid;
	int rc = 0;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *pTcon;

	if (cifs_sb)
		pTcon = cifs_sb->tcon;
	else
		return -EIO;

	xid = GetXid();
	if (pTcon) {
		cFYI(1, ("set type: 0x%x id: %d", quota_type, qid));
	} else {
		rc = -EIO;