proc.c

linux 内核源代码

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	smb_setup_header(req, SMBlseek, 4, 0);
	WSET(req->rq_header, smb_vwv0, fileid);
	WSET(req->rq_header, smb_vwv1, mode);
	DSET(req->rq_header, smb_vwv2, offset);
	req->rq_flags |= SMB_REQ_NORETRY;

	result = smb_request_ok(req, SMBlseek, 2, 0);
	if (result < 0) {
		result = 0;
		goto out_free;
	}

	result = DVAL(req->rq_header, smb_vwv0);
out_free:
	smb_rput(req);
out:
	return result;
}

static int
smb_proc_open(struct smb_sb_info *server, struct dentry *dentry, int wish)
{
	struct inode *ino = dentry->d_inode;
	struct smb_inode_info *ei = SMB_I(ino);
	int mode, read_write = 0x42, read_only = 0x40;
	int res;
	char *p;
	struct smb_request *req;

	/*
	 * Attempt to open r/w, unless there are no write privileges.
	 */
	mode = read_write;
	if (!(ino->i_mode & (S_IWUSR | S_IWGRP | S_IWOTH)))
		mode = read_only;
#if 0
	/* FIXME: why is this code not in? below we fix it so that a caller
	   wanting RO doesn't get RW. smb_revalidate_inode does some 
	   optimization based on access mode. tail -f needs it to be correct.

	   We must open rw since we don't do the open if called a second time
	   with different 'wish'. Is that not supported by smb servers? */
	if (!(wish & (O_WRONLY | O_RDWR)))
		mode = read_only;
#endif

	res = -ENOMEM;
	if (! (req = smb_alloc_request(server, PAGE_SIZE)))
		goto out;

      retry:
	p = smb_setup_header(req, SMBopen, 2, 0);
	WSET(req->rq_header, smb_vwv0, mode);
	WSET(req->rq_header, smb_vwv1, aSYSTEM | aHIDDEN | aDIR);
	res = smb_simple_encode_path(req, &p, dentry, NULL);
	if (res < 0)
		goto out_free;
	smb_setup_bcc(req, p);

	res = smb_request_ok(req, SMBopen, 7, 0);
	if (res != 0) {
		if (mode == read_write &&
		    (res == -EACCES || res == -ETXTBSY || res == -EROFS))
		{
			VERBOSE("%s/%s R/W failed, error=%d, retrying R/O\n",
				DENTRY_PATH(dentry), res);
			mode = read_only;
			req->rq_flags = 0;
			goto retry;
		}
		goto out_free;
	}
	/* We should now have data in vwv[0..6]. */

	ei->fileid = WVAL(req->rq_header, smb_vwv0);
	ei->attr   = WVAL(req->rq_header, smb_vwv1);
	/* smb_vwv2 has mtime */
	/* smb_vwv4 has size  */
	ei->access = (WVAL(req->rq_header, smb_vwv6) & SMB_ACCMASK);
	ei->open = server->generation;

out_free:
	smb_rput(req);
out:
	return res;
}

/*
 * Make sure the file is open, and check that the access
 * is compatible with the desired access.
 */
int
smb_open(struct dentry *dentry, int wish)
{
	struct inode *inode = dentry->d_inode;
	int result;
	__u16 access;

	result = -ENOENT;
	if (!inode) {
		printk(KERN_ERR "smb_open: no inode for dentry %s/%s\n",
		       DENTRY_PATH(dentry));
		goto out;
	}

	if (!smb_is_open(inode)) {
		struct smb_sb_info *server = server_from_inode(inode);
		result = 0;
		if (!smb_is_open(inode))
			result = smb_proc_open(server, dentry, wish);
		if (result)
			goto out;
		/*
		 * A successful open means the path is still valid ...
		 */
		smb_renew_times(dentry);
	}

	/*
	 * Check whether the access is compatible with the desired mode.
	 */
	result = 0;
	access = SMB_I(inode)->access;
	if (access != wish && access != SMB_O_RDWR) {
		PARANOIA("%s/%s access denied, access=%x, wish=%x\n",
			 DENTRY_PATH(dentry), access, wish);
		result = -EACCES;
	}
out:
	return result;
}

static int 
smb_proc_close(struct smb_sb_info *server, __u16 fileid, __u32 mtime)
{
	struct smb_request *req;
	int result = -ENOMEM;

	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	smb_setup_header(req, SMBclose, 3, 0);
	WSET(req->rq_header, smb_vwv0, fileid);
	DSET(req->rq_header, smb_vwv1, utc2local(server, mtime));
	req->rq_flags |= SMB_REQ_NORETRY;
	result = smb_request_ok(req, SMBclose, 0, 0);

	smb_rput(req);
out:
	return result;
}

/*
 * Win NT 4.0 has an apparent bug in that it fails to update the
 * modify time when writing to a file. As a workaround, we update
 * both modify and access time locally, and post the times to the
 * server when closing the file.
 */
static int 
smb_proc_close_inode(struct smb_sb_info *server, struct inode * ino)
{
	struct smb_inode_info *ei = SMB_I(ino);
	int result = 0;
	if (smb_is_open(ino))
	{
		/*
		 * We clear the open flag in advance, in case another
 		 * process observes the value while we block below.
		 */
		ei->open = 0;

		/*
		 * Kludge alert: SMB timestamps are accurate only to
		 * two seconds ... round the times to avoid needless
		 * cache invalidations!
		 */
		if (ino->i_mtime.tv_sec & 1) { 
			ino->i_mtime.tv_sec--;
			ino->i_mtime.tv_nsec = 0; 
		}
		if (ino->i_atime.tv_sec & 1) {
			ino->i_atime.tv_sec--;
			ino->i_atime.tv_nsec = 0;
		}
		/*
		 * If the file is open with write permissions,
		 * update the time stamps to sync mtime and atime.
		 */
		if ((server->opt.capabilities & SMB_CAP_UNIX) == 0 &&
		    (server->opt.protocol >= SMB_PROTOCOL_LANMAN2) &&
		    !(ei->access == SMB_O_RDONLY))
		{
			struct smb_fattr fattr;
			smb_get_inode_attr(ino, &fattr);
			smb_proc_setattr_ext(server, ino, &fattr);
		}

		result = smb_proc_close(server, ei->fileid, ino->i_mtime.tv_sec);
		/*
		 * Force a revalidation after closing ... some servers
		 * don't post the size until the file has been closed.
		 */
		if (server->opt.protocol < SMB_PROTOCOL_NT1)
			ei->oldmtime = 0;
		ei->closed = jiffies;
	}
	return result;
}

int
smb_close(struct inode *ino)
{
	int result = 0;

	if (smb_is_open(ino)) {
		struct smb_sb_info *server = server_from_inode(ino);
		result = smb_proc_close_inode(server, ino);
	}
	return result;
}

/*
 * This is used to close a file following a failed instantiate.
 * Since we don't have an inode, we can't use any of the above.
 */
int
smb_close_fileid(struct dentry *dentry, __u16 fileid)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	int result;

	result = smb_proc_close(server, fileid, get_seconds());
	return result;
}

/* In smb_proc_read and smb_proc_write we do not retry, because the
   file-id would not be valid after a reconnection. */

static void
smb_proc_read_data(struct smb_request *req)
{
	req->rq_iov[0].iov_base = req->rq_buffer;
	req->rq_iov[0].iov_len  = 3;

	req->rq_iov[1].iov_base = req->rq_page;
	req->rq_iov[1].iov_len  = req->rq_rsize;
	req->rq_iovlen = 2;

	req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;
}

static int
smb_proc_read(struct inode *inode, loff_t offset, int count, char *data)
{
	struct smb_sb_info *server = server_from_inode(inode);
	__u16 returned_count, data_len;
	unsigned char *buf;
	int result;
	struct smb_request *req;
	u8 rbuf[4];

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	smb_setup_header(req, SMBread, 5, 0);
	buf = req->rq_header;
	WSET(buf, smb_vwv0, SMB_I(inode)->fileid);
	WSET(buf, smb_vwv1, count);
	DSET(buf, smb_vwv2, offset);
	WSET(buf, smb_vwv4, 0);

	req->rq_page = data;
	req->rq_rsize = count;
	req->rq_callback = smb_proc_read_data;
	req->rq_buffer = rbuf;
	req->rq_flags |= SMB_REQ_NORETRY | SMB_REQ_STATIC;

	result = smb_request_ok(req, SMBread, 5, -1);
	if (result < 0)
		goto out_free;
	returned_count = WVAL(req->rq_header, smb_vwv0);

	data_len = WVAL(rbuf, 1);

	if (returned_count != data_len) {
		printk(KERN_NOTICE "smb_proc_read: returned != data_len\n");
		printk(KERN_NOTICE "smb_proc_read: ret_c=%d, data_len=%d\n",
		       returned_count, data_len);
	}
	result = data_len;

out_free:
	smb_rput(req);
out:
	VERBOSE("ino=%ld, fileid=%d, count=%d, result=%d\n",
		inode->i_ino, SMB_I(inode)->fileid, count, result);
	return result;
}

static int
smb_proc_write(struct inode *inode, loff_t offset, int count, const char *data)
{
	struct smb_sb_info *server = server_from_inode(inode);
	int result;
	u16 fileid = SMB_I(inode)->fileid;
	u8 buf[4];
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	VERBOSE("ino=%ld, fileid=%d, count=%d@%Ld\n",
		inode->i_ino, fileid, count, offset);

	smb_setup_header(req, SMBwrite, 5, count + 3);
	WSET(req->rq_header, smb_vwv0, fileid);
	WSET(req->rq_header, smb_vwv1, count);
	DSET(req->rq_header, smb_vwv2, offset);
	WSET(req->rq_header, smb_vwv4, 0);

	buf[0] = 1;
	WSET(buf, 1, count);	/* yes, again ... */
	req->rq_iov[1].iov_base = buf;
	req->rq_iov[1].iov_len = 3;
	req->rq_iov[2].iov_base = (char *) data;
	req->rq_iov[2].iov_len = count;
	req->rq_iovlen = 3;
	req->rq_flags |= SMB_REQ_NORETRY;

	result = smb_request_ok(req, SMBwrite, 1, 0);
	if (result >= 0)
		result = WVAL(req->rq_header, smb_vwv0);

	smb_rput(req);
out:
	return result;
}

/*
 * In smb_proc_readX and smb_proc_writeX we do not retry, because the
 * file-id would not be valid after a reconnection.
 */

#define SMB_READX_MAX_PAD      64
static void
smb_proc_readX_data(struct smb_request *req)
{
	/* header length, excluding the netbios length (-4) */
	int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;
	int data_off = WVAL(req->rq_header, smb_vwv6);

	/*
	 * Some genius made the padding to the data bytes arbitrary.
	 * So we must first calculate the amount of padding used by the server.
	 */
	data_off -= hdrlen;
	if (data_off > SMB_READX_MAX_PAD || data_off < 0) {
		PARANOIA("offset is larger than SMB_READX_MAX_PAD or negative!\n");
		PARANOIA("%d > %d || %d < 0\n", data_off, SMB_READX_MAX_PAD, data_off);
		req->rq_rlen = req->rq_bufsize + 1;
		return;
	}
	req->rq_iov[0].iov_base = req->rq_buffer;
	req->rq_iov[0].iov_len  = data_off;

	req->rq_iov[1].iov_base = req->rq_page;
	req->rq_iov[1].iov_len  = req->rq_rsize;
	req->rq_iovlen = 2;

	req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;
}

static int
smb_proc_readX(struct inode *inode, loff_t offset, int count, char *data)
{
	struct smb_sb_info *server = server_from_inode(inode);
	unsigned char *buf;
	int result;
	struct smb_request *req;
	static char pad[SMB_READX_MAX_PAD];

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	smb_setup_header(req, SMBreadX, 12, 0);
	buf = req->rq_header;
	WSET(buf, smb_vwv0, 0x00ff);
	WSET(buf, smb_vwv1, 0);
	WSET(buf, smb_vwv2, SMB_I(inode)->fileid);
	DSET(buf, smb_vwv3, (u32)offset);               /* low 32 bits */
	WSET(buf, smb_vwv5, count);
	WSET(buf, smb_vwv6, 0);
	DSET(buf, smb_vwv7, 0);
	WSET(buf, smb_vwv9, 0);
	DSET(buf, smb_vwv10, (u32)(offset >> 32));      /* high 32 bits */
	WSET(buf, smb_vwv11, 0);

	req->rq_page = data;
	req->rq_rsize = count;
	req->rq_callback = smb_proc_readX_data;
	req->rq_buffer = pad;
	req->rq_bufsize = SMB_READX_MAX_PAD;
	req->rq_flags |= SMB_REQ_STATIC | SMB_REQ_NORETRY;

	result = smb_request_ok(req, SMBreadX, 12, -1);
	if (result < 0)
		goto out_free;
	result = WVAL(req->rq_header, smb_vwv5);

out_free:
	smb_rput(req);
out:
	VERBOSE("ino=%ld, fileid=%d, count=%d, result=%d\n",
		inode->i_ino, SMB_I(inode)->fileid, count, result);
	return result;
}

static int
smb_proc_writeX(struct inode *inode, loff_t offset, int count, const char *data)
{
	struct smb_sb_info *server = server_from_inode(inode);
	int result;
	u8 *p;
	static u8 pad[4];
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	VERBOSE("ino=%ld, fileid=%d, count=%d@%Ld\n",
		inode->i_ino, SMB_I(inode)->fileid, count, offset);

	p = smb_setup_header(req, SMBwriteX, 14, count + 1);
	WSET(req->rq_header, smb_vwv0, 0x00ff);
	WSET(req->rq_header, smb_vwv1, 0);
	WSET(req->rq_header, smb_vwv2, SMB_I(inode)->fileid);
	DSET(req->rq_header, smb_vwv3, (u32)offset);	/* low 32 bits */
	DSET(req->rq_header, smb_vwv5, 0);
	WSET(req->rq_header, smb_vwv7, 0);		/* write mode */
	WSET(req->rq_header, smb_vwv8, 0);
	WSET(req->rq_header, smb_vwv9, 0);
	WSET(req->rq_header, smb_vwv10, count);		/* data length */
	WSET(req->rq_header, smb_vwv11, smb_vwv12 + 2 + 1);
	DSET(req->rq_header, smb_vwv12, (u32)(offset >> 32));

	req->rq_iov[1].iov_base = pad;
	req->rq_iov[1].iov_len = 1;
	req->rq_iov[2].iov_base = (char *) data;
	req->rq_iov[2].iov_len = count;
	req->rq_iovlen = 3;
	req->rq_flags |= SMB_REQ_NORETRY;

	result = smb_request_ok(req, SMBwriteX, 6, 0);
 	if (result >= 0)
		result = WVAL(req->rq_header, smb_vwv2);

	smb_rput(req);
out:
	return result;
}

int
smb_proc_create(struct dentry *dentry, __u16 attr, time_t ctime, __u16 *fileid)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	char *p;
	int result;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, PAGE_SIZE)))
		goto out;

	p = smb_setup_header(req, SMBcreate, 3, 0);
	WSET(req->rq_header, smb_vwv0, attr);
	DSET(req->rq_header, smb_vwv1, utc2local(server, ctime));
	result = smb_simple_encode_path(req, &p, dentry, NULL);
	if (result < 0)
		goto out_free;
	smb_setup_bcc(req, p);

	result = smb_request_ok(req, SMBcreate, 1, 0);
	if (result < 0)
		goto out_free;

	*fileid = WVAL(req->rq_header, smb_vwv0);
	result = 0;

out_free:
	smb_rput(req);
out:
	return result;
}

int
smb_proc_mv(struct dentry *old_dentry, struct dentry *new_dentry)
{
	struct smb_sb_info *server = server_from_dentry(old_dentry);
	char *p;
	int result;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, PAGE_SIZE)))
		goto out;

	p = smb_setup_header(req, SMBmv, 1, 0);
	WSET(req->rq_header, smb_vwv0, aSYSTEM | aHIDDEN | aDIR);
	result = smb_simple_encode_path(req, &p, old_dentry, NULL);
	if (result < 0)
		goto out_free;
	result = smb_simple_encode_path(req, &p, new_dentry, NULL);
	if (result < 0)
		goto out_free;
	smb_setup_bcc(req, p);

	if ((result = smb_request_ok(req, SMBmv, 0, 0)) < 0)
		goto out_free;
	result = 0;

out_free:
	smb_rput(req);
out:
	return result;
}