Re: [PATCH v2 05/24] CIFS: Make transport routines work with SMB2

[Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Wed, 20 Jun 2012 18:30:45 +0400
Pavel Shilovsky <pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org> wrote:

> From: Pavel Shilovsky <piastry-7qunaywFIewox3rIn2DAYQ@public.gmane.org>
> 
> Signed-off-by: Pavel Shilovsky <piastry-7qunaywFIewox3rIn2DAYQ@public.gmane.org>
> ---
>  fs/cifs/Makefile        |    2 +-
>  fs/cifs/cifsglob.h      |    5 ++
>  fs/cifs/cifsproto.h     |    1 +
>  fs/cifs/smb1ops.c       |    1 +
>  fs/cifs/smb2ops.c       |   17 +++++
>  fs/cifs/smb2pdu.h       |   59 ++++++++++++++++++
>  fs/cifs/smb2proto.h     |    5 ++
>  fs/cifs/smb2transport.c |  151 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/cifs/transport.c     |   13 ++--
>  9 files changed, 246 insertions(+), 8 deletions(-)
>  create mode 100644 fs/cifs/smb2transport.c
> 
> diff --git a/fs/cifs/Makefile b/fs/cifs/Makefile
> index 4a77271..a73d7f8 100644
> --- a/fs/cifs/Makefile
> +++ b/fs/cifs/Makefile
> @@ -16,4 +16,4 @@ cifs-$(CONFIG_CIFS_DFS_UPCALL) += dns_resolve.o cifs_dfs_ref.o
>  
>  cifs-$(CONFIG_CIFS_FSCACHE) += fscache.o cache.o
>  
> -cifs-$(CONFIG_CIFS_SMB2) += smb2ops.o smb2maperror.o
> +cifs-$(CONFIG_CIFS_SMB2) += smb2ops.o smb2maperror.o smb2transport.o
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 6d18962..3575f0f 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -22,6 +22,7 @@
>  #include <linux/in.h>
>  #include <linux/in6.h>
>  #include <linux/slab.h>
> +#include <linux/mempool.h>
>  #include <linux/workqueue.h>
>  #include "cifs_fs_sb.h"
>  #include "cifsacl.h"
> @@ -218,6 +219,7 @@ struct smb_version_values {
>  	size_t		header_size;
>  	size_t		max_header_size;
>  	size_t		read_rsp_size;
> +	__le16		lock_cmd;
>  };
>  
>  #define HEADER_SIZE(server) (server->vals->header_size)
> @@ -812,6 +814,7 @@ typedef void (mid_callback_t)(struct mid_q_entry *mid);
>  /* one of these for every pending CIFS request to the server */
>  struct mid_q_entry {
>  	struct list_head qhead;	/* mids waiting on reply from this server */
> +	struct TCP_Server_Info *server;	/* server corresponding to this mid */
>  	__u64 mid;		/* multiplex id */
>  	__u32 pid;		/* process id */
>  	__u32 sequence_number;  /* for CIFS signing */
> @@ -1153,6 +1156,8 @@ void cifs_oplock_break(struct work_struct *work);
>  extern const struct slow_work_ops cifs_oplock_break_ops;
>  extern struct workqueue_struct *cifsiod_wq;
>  
> +extern mempool_t *cifs_mid_poolp;
> +
>  /* Operations for different SMB versions */
>  #define SMB1_VERSION_STRING	"1.0"
>  extern struct smb_version_operations smb1_operations;
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index 7ae25c2..80d35ee 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -68,6 +68,7 @@ extern char *cifs_compose_mount_options(const char *sb_mountdata,
>  extern struct mid_q_entry *AllocMidQEntry(const struct smb_hdr *smb_buffer,
>  					struct TCP_Server_Info *server);
>  extern void DeleteMidQEntry(struct mid_q_entry *midEntry);
> +extern void cifs_wake_up_task(struct mid_q_entry *mid);
>  extern int cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
>  			   unsigned int nvec, mid_receive_t *receive,
>  			   mid_callback_t *callback, void *cbdata,
> diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
> index 728595f..8f87386 100644
> --- a/fs/cifs/smb1ops.c
> +++ b/fs/cifs/smb1ops.c
> @@ -445,4 +445,5 @@ struct smb_version_values smb1_values = {
>  	.header_size = sizeof(struct smb_hdr),
>  	.max_header_size = MAX_CIFS_HDR_SIZE,
>  	.read_rsp_size = sizeof(READ_RSP),
> +	.lock_cmd = cpu_to_le16(SMB_COM_LOCKING_ANDX),
>  };
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index f065e89..09530f4 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -18,10 +18,27 @@
>   */
>  
>  #include "cifsglob.h"
> +#include "smb2pdu.h"
> +#include "smb2proto.h"
> +
> +static __u64
> +smb2_get_next_mid(struct TCP_Server_Info *server)
> +{
> +	__u64 mid;
> +	/* for SMB2 we need the current value */
> +	spin_lock(&GlobalMid_Lock);
> +	mid = server->CurrentMid++;
> +	spin_unlock(&GlobalMid_Lock);
> +	return mid;
> +}
>  
>  struct smb_version_operations smb21_operations = {
> +	.setup_request = smb2_setup_request,
> +	.check_receive = smb2_check_receive,
> +	.get_next_mid = smb2_get_next_mid,
>  };
>  
>  struct smb_version_values smb21_values = {
>  	.version_string = SMB21_VERSION_STRING,
> +	.lock_cmd = SMB2_LOCK,
>  };
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index d35ac68..c7f52e3 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -27,6 +27,65 @@
>  #include <net/sock.h>
>  
>  /*
> + * Note that, due to trying to use names similar to the protocol specifications,
> + * there are many mixed case field names in the structures below.  Although
> + * this does not match typical Linux kernel style, it is necessary to be
> + * be able to match against the protocol specfication.
> + *
> + * SMB2 commands
> + * Some commands have minimal (wct=0,bcc=0), or uninteresting, responses
> + * (ie no useful data other than the SMB error code itself) and are marked such.
> + * Knowing this helps avoid response buffer allocations and copy in some cases.
> + */
> +
> +/* List of commands in host endian */
> +#define SMB2_NEGOTIATE_HE	0x0000
> +#define SMB2_SESSION_SETUP_HE	0x0001
> +#define SMB2_LOGOFF_HE		0x0002 /* trivial request/resp */
> +#define SMB2_TREE_CONNECT_HE	0x0003
> +#define SMB2_TREE_DISCONNECT_HE	0x0004 /* trivial req/resp */
> +#define SMB2_CREATE_HE		0x0005
> +#define SMB2_CLOSE_HE		0x0006
> +#define SMB2_FLUSH_HE		0x0007 /* trivial resp */
> +#define SMB2_READ_HE		0x0008
> +#define SMB2_WRITE_HE		0x0009
> +#define SMB2_LOCK_HE		0x000A
> +#define SMB2_IOCTL_HE		0x000B
> +#define SMB2_CANCEL_HE		0x000C
> +#define SMB2_ECHO_HE		0x000D
> +#define SMB2_QUERY_DIRECTORY_HE	0x000E
> +#define SMB2_CHANGE_NOTIFY_HE	0x000F
> +#define SMB2_QUERY_INFO_HE	0x0010
> +#define SMB2_SET_INFO_HE	0x0011
> +#define SMB2_OPLOCK_BREAK_HE	0x0012
> +
> +/* The same list in little endian */
> +#define SMB2_NEGOTIATE		cpu_to_le16(SMB2_NEGOTIATE_HE)
> +#define SMB2_SESSION_SETUP	cpu_to_le16(SMB2_SESSION_SETUP_HE)
> +#define SMB2_LOGOFF		cpu_to_le16(SMB2_LOGOFF_HE)
> +#define SMB2_TREE_CONNECT	cpu_to_le16(SMB2_TREE_CONNECT_HE)
> +#define SMB2_TREE_DISCONNECT	cpu_to_le16(SMB2_TREE_DISCONNECT_HE)
> +#define SMB2_CREATE		cpu_to_le16(SMB2_CREATE_HE)
> +#define SMB2_CLOSE		cpu_to_le16(SMB2_CLOSE_HE)
> +#define SMB2_FLUSH		cpu_to_le16(SMB2_FLUSH_HE)
> +#define SMB2_READ		cpu_to_le16(SMB2_READ_HE)
> +#define SMB2_WRITE		cpu_to_le16(SMB2_WRITE_HE)
> +#define SMB2_LOCK		cpu_to_le16(SMB2_LOCK_HE)
> +#define SMB2_IOCTL		cpu_to_le16(SMB2_IOCTL_HE)
> +#define SMB2_CANCEL		cpu_to_le16(SMB2_CANCEL_HE)
> +#define SMB2_ECHO		cpu_to_le16(SMB2_ECHO_HE)
> +#define SMB2_QUERY_DIRECTORY	cpu_to_le16(SMB2_QUERY_DIRECTORY_HE)
> +#define SMB2_CHANGE_NOTIFY	cpu_to_le16(SMB2_CHANGE_NOTIFY_HE)
> +#define SMB2_QUERY_INFO		cpu_to_le16(SMB2_QUERY_INFO_HE)
> +#define SMB2_SET_INFO		cpu_to_le16(SMB2_SET_INFO_HE)
> +#define SMB2_OPLOCK_BREAK	cpu_to_le16(SMB2_OPLOCK_BREAK_HE)
> +
> +#define NUMBER_OF_SMB2_COMMANDS	0x0013
> +
> +/* BB FIXME - analyze following length BB */
> +#define MAX_SMB2_HDR_SIZE 0x78 /* 4 len + 64 hdr + (2*24 wct) + 2 bct + 2 pad */
> +
> +/*
>   * SMB2 Header Definition
>   *
>   * "MBZ" :  Must be Zero
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index 08249ee..0e59afb 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -34,4 +34,9 @@ struct statfs;
>   */
>  extern int map_smb2_to_linux_error(char *buf, bool log_err);
>  
> +extern int smb2_check_receive(struct mid_q_entry *mid,
> +			      struct TCP_Server_Info *server, bool log_error);
> +extern int smb2_setup_request(struct cifs_ses *ses, struct kvec *iov,
> +			      unsigned int nvec, struct mid_q_entry **ret_mid);
> +
>  #endif			/* _SMB2PROTO_H */
> diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
> new file mode 100644
> index 0000000..b4b6b9a
> --- /dev/null
> +++ b/fs/cifs/smb2transport.c
> @@ -0,0 +1,151 @@
> +/*
> + *   fs/cifs/smb2transport.c
> + *
> + *   Copyright (C) International Business Machines  Corp., 2002, 2011
> + *                 Etersoft, 2012
> + *   Author(s): Steve French (sfrench-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org)
> + *              Jeremy Allison (jra-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org) 2006
> + *              Pavel Shilovsky (pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org) 2012
> + *
> + *   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
> + */
> +
> +#include <linux/fs.h>
> +#include <linux/list.h>
> +#include <linux/wait.h>
> +#include <linux/net.h>
> +#include <linux/delay.h>
> +#include <linux/uaccess.h>
> +#include <asm/processor.h>
> +#include <linux/mempool.h>
> +#include "smb2pdu.h"
> +#include "cifsglob.h"
> +#include "cifsproto.h"
> +#include "smb2proto.h"
> +#include "cifs_debug.h"
> +#include "smb2status.h"
> +
> +/*
> + * Set message id for the request. Should be called after wait_for_free_request
> + * and when srv_mutex is held.
> + */
> +static inline void
> +smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
> +{
> +	hdr->MessageId = get_next_mid(server);
> +}
> +
> +static struct mid_q_entry *
> +smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
> +		     struct TCP_Server_Info *server)
> +{
> +	struct mid_q_entry *temp;
> +
> +	if (server == NULL) {
> +		cERROR(1, "Null TCP session in smb2_mid_entry_alloc");
> +		return NULL;
> +	}
> +
> +	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
> +	if (temp == NULL)
> +		return temp;
> +	else {
> +		memset(temp, 0, sizeof(struct mid_q_entry));
> +		temp->mid = smb_buffer->MessageId;	/* always LE */
> +		temp->pid = current->pid;
> +		temp->command = smb_buffer->Command;	/* Always LE */
> +		temp->when_alloc = jiffies;
> +		temp->server = server;
> +
> +		/*
> +		 * The default is for the mid to be synchronous, so the
> +		 * default callback just wakes up the current task.
> +		 */
> +		temp->callback = cifs_wake_up_task;
> +		temp->callback_data = current;
> +	}
> +
> +	atomic_inc(&midCount);
> +	temp->mid_state = MID_REQUEST_ALLOCATED;
> +	return temp;
> +}
> +
> +static int
> +smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_hdr *buf,
> +		   struct mid_q_entry **mid)
> +{
> +	if (ses->server->tcpStatus == CifsExiting)
> +		return -ENOENT;
> +
> +	if (ses->server->tcpStatus == CifsNeedReconnect) {
> +		cFYI(1, "tcp session dead - return to caller to retry");
> +		return -EAGAIN;
> +	}
> +
> +	if (ses->status != CifsGood) {
> +		/* check if SMB2 session is bad because we are setting it up */
> +		if ((buf->Command != SMB2_SESSION_SETUP) &&
> +		    (buf->Command != SMB2_NEGOTIATE))
> +			return -EAGAIN;
> +		/* else ok - we are setting up session */
> +	}
> +	*mid = smb2_mid_entry_alloc(buf, ses->server);
> +	if (*mid == NULL)
> +		return -ENOMEM;
> +	spin_lock(&GlobalMid_Lock);
> +	list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
> +	spin_unlock(&GlobalMid_Lock);
> +	return 0;
> +}
> +
> +int
> +smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
> +		   bool log_error)
> +{
> +	unsigned int len = get_rfc1002_length(mid->resp_buf);
> +
> +	dump_smb(mid->resp_buf, min_t(u32, 80, len));
> +	/* convert the length into a more usable form */
> +	/* BB - uncomment with SMB2 signing implementation */
> +	/* if ((len > 24) &&
> +	    (server->sec_mode & (SECMODE_SIGN_REQUIRED|SECMODE_SIGN_ENABLED))) {
> +		if (smb2_verify_signature(mid->resp_buf, server))
> +			cERROR(1, "Unexpected SMB signature");
> +	} */
> +
> +	return map_smb2_to_linux_error(mid->resp_buf, log_error);
> +}
> +
> +int
> +smb2_setup_request(struct cifs_ses *ses, struct kvec *iov,
> +		   unsigned int nvec, struct mid_q_entry **ret_mid)
> +{
> +	int rc;
> +	struct smb2_hdr *hdr = (struct smb2_hdr *)iov[0].iov_base;
> +	struct mid_q_entry *mid;
> +
> +	smb2_seq_num_into_buf(ses->server, hdr);
> +
> +	rc = smb2_get_mid_entry(ses, hdr, &mid);
> +	if (rc)
> +		return rc;
> +	/* rc = smb2_sign_smb2(iov, nvec, ses->server);
> +	if (rc)
> +		delete_mid(mid); */
> +	*ret_mid = mid;
> +	return rc;
> +}
> +
> +/* BB add missing functions here */
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index bfbf0f9..bd51339 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -35,10 +35,8 @@
>  #include "cifsproto.h"
>  #include "cifs_debug.h"
>  
> -extern mempool_t *cifs_mid_poolp;
> -
> -static void
> -wake_up_task(struct mid_q_entry *mid)
> +void
> +cifs_wake_up_task(struct mid_q_entry *mid)
>  {
>  	wake_up_process(mid->callback_data);
>  }
> @@ -65,12 +63,13 @@ AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
>  	/*	do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
>  		/* when mid allocated can be before when sent */
>  		temp->when_alloc = jiffies;
> +		temp->server = server;
>  
>  		/*
>  		 * The default is for the mid to be synchronous, so the
>  		 * default callback just wakes up the current task.
>  		 */
> -		temp->callback = wake_up_task;
> +		temp->callback = cifs_wake_up_task;
>  		temp->callback_data = current;
>  	}
>  
> @@ -83,6 +82,7 @@ void
>  DeleteMidQEntry(struct mid_q_entry *midEntry)
>  {
>  #ifdef CONFIG_CIFS_STATS2
> +	__le16 command = midEntry->server->vals->lock_cmd;
>  	unsigned long now;
>  #endif
>  	midEntry->mid_state = MID_FREE;
> @@ -96,8 +96,7 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
>  	/* commands taking longer than one second are indications that
>  	   something is wrong, unless it is quite a slow link or server */
>  	if ((now - midEntry->when_alloc) > HZ) {
> -		if ((cifsFYI & CIFS_TIMER) &&
> -		    (midEntry->command != cpu_to_le16(SMB_COM_LOCKING_ANDX))) {
> +		if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
>  			printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
>  			       midEntry->command, midEntry->mid);
>  			printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",

Looks fine, but I wonder whether we'd be better off just getting rid of
the above warning and the lock_cmd field. The lock_cmd is only used
there, and that firing off warnings just because the call took more
than 1s seems goofy to me. We know that writes long past the EOF can
take a very long time with MS servers. Is the above warning really of
value?

That's a minor nit though and something we can remove later if we
decide to.

Reviewed-by: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>