Commit 88257360 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Move get_next_mid to ops struct 



Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 7f0adb53

fs/cifs/cifsglob.h

+7 −0
Original line number Diff line number Diff line
@@ -174,6 +174,7 @@ struct smb_version_operations { 
	void (*add_credits)(struct TCP_Server_Info *, const unsigned int);

	void (*set_credits)(struct TCP_Server_Info *, const int);

	int * (*get_credits_field)(struct TCP_Server_Info *);

	__u64 (*get_next_mid)(struct TCP_Server_Info *);

	/* data offset from read response message */

	unsigned int (*read_data_offset)(char *);

	/* data length from read response message */
@@ -399,6 +400,12 @@ set_credits(struct TCP_Server_Info *server, const int val) 
	server->ops->set_credits(server, val);

}



static inline __u64

get_next_mid(struct TCP_Server_Info *server)

{

	return server->ops->get_next_mid(server);

}



/*

 * Macros to allow the TCP_Server_Info->net field and related code to drop out

 * when CONFIG_NET_NS isn't set.

fs/cifs/cifsproto.h

+0 −1
Original line number Diff line number Diff line
@@ -114,7 +114,6 @@ extern int small_smb_init_no_tc(const int smb_cmd, const int wct, 
				void **request_buf);

extern int CIFS_SessSetup(unsigned int xid, struct cifs_ses *ses,

			     const struct nls_table *nls_cp);

extern __u64 GetNextMid(struct TCP_Server_Info *server);

extern struct timespec cifs_NTtimeToUnix(__le64 utc_nanoseconds_since_1601);

extern u64 cifs_UnixTimeToNT(struct timespec);

extern struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time,

fs/cifs/cifssmb.c

+4 −4
Original line number Diff line number Diff line
@@ -268,7 +268,7 @@ small_smb_init_no_tc(const int smb_command, const int wct, 
		return rc;



	buffer = (struct smb_hdr *)*request_buf;

	buffer->Mid = GetNextMid(ses->server);

	buffer->Mid = get_next_mid(ses->server);

	if (ses->capabilities & CAP_UNICODE)

		buffer->Flags2 |= SMBFLG2_UNICODE;

	if (ses->capabilities & CAP_STATUS32)
@@ -402,7 +402,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses) 


	cFYI(1, "secFlags 0x%x", secFlags);



	pSMB->hdr.Mid = GetNextMid(server);

	pSMB->hdr.Mid = get_next_mid(server);

	pSMB->hdr.Flags2 |= (SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS);



	if ((secFlags & CIFSSEC_MUST_KRB5) == CIFSSEC_MUST_KRB5)
@@ -782,7 +782,7 @@ CIFSSMBLogoff(const int xid, struct cifs_ses *ses) 
		return rc;

	}



	pSMB->hdr.Mid = GetNextMid(ses->server);

	pSMB->hdr.Mid = get_next_mid(ses->server);



	if (ses->server->sec_mode &

		   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
@@ -4762,7 +4762,7 @@ CIFSGetDFSRefer(const int xid, struct cifs_ses *ses, 


	/* server pointer checked in called function,

	but should never be null here anyway */

	pSMB->hdr.Mid = GetNextMid(ses->server);

	pSMB->hdr.Mid = get_next_mid(ses->server);

	pSMB->hdr.Tid = ses->ipc_tid;

	pSMB->hdr.Uid = ses->Suid;

	if (ses->capabilities & CAP_STATUS32)

fs/cifs/connect.c

+1 −1
Original line number Diff line number Diff line
@@ -3940,7 +3940,7 @@ CIFSTCon(unsigned int xid, struct cifs_ses *ses, 
	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,

			NULL /*no tid */ , 4 /*wct */ );



	smb_buffer->Mid = GetNextMid(ses->server);

	smb_buffer->Mid = get_next_mid(ses->server);

	smb_buffer->Uid = ses->Suid;

	pSMB = (TCONX_REQ *) smb_buffer;

	pSMBr = (TCONX_RSP *) smb_buffer_response;

fs/cifs/misc.c

+1 −88
Original line number Diff line number Diff line
@@ -212,93 +212,6 @@ cifs_small_buf_release(void *buf_to_free) 
	return;

}



/*

 * Find a free multiplex id (SMB mid). Otherwise there could be

 * mid collisions which might cause problems, demultiplexing the

 * wrong response to this request. Multiplex ids could collide if

 * one of a series requests takes much longer than the others, or

 * if a very large number of long lived requests (byte range

 * locks or FindNotify requests) are pending. No more than

 * 64K-1 requests can be outstanding at one time. If no

 * mids are available, return zero. A future optimization

 * could make the combination of mids and uid the key we use

 * to demultiplex on (rather than mid alone).

 * In addition to the above check, the cifs demultiplex

 * code already used the command code as a secondary

 * check of the frame and if signing is negotiated the

 * response would be discarded if the mid were the same

 * but the signature was wrong. Since the mid is not put in the

 * pending queue until later (when it is about to be dispatched)

 * we do have to limit the number of outstanding requests

 * to somewhat less than 64K-1 although it is hard to imagine

 * so many threads being in the vfs at one time.

 */

__u64 GetNextMid(struct TCP_Server_Info *server)

{

	__u64 mid = 0;

	__u16 last_mid, cur_mid;

	bool collision;



	spin_lock(&GlobalMid_Lock);



	/* mid is 16 bit only for CIFS/SMB */

	cur_mid = (__u16)((server->CurrentMid) & 0xffff);

	/* we do not want to loop forever */

	last_mid = cur_mid;

	cur_mid++;



	/*

	 * This nested loop looks more expensive than it is.

	 * In practice the list of pending requests is short,

	 * fewer than 50, and the mids are likely to be unique

	 * on the first pass through the loop unless some request

	 * takes longer than the 64 thousand requests before it

	 * (and it would also have to have been a request that

	 * did not time out).

	 */

	while (cur_mid != last_mid) {

		struct mid_q_entry *mid_entry;

		unsigned int num_mids;



		collision = false;

		if (cur_mid == 0)

			cur_mid++;



		num_mids = 0;

		list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {

			++num_mids;

			if (mid_entry->mid == cur_mid &&

			    mid_entry->mid_state == MID_REQUEST_SUBMITTED) {

				/* This mid is in use, try a different one */

				collision = true;

				break;

			}

		}



		/*

		 * if we have more than 32k mids in the list, then something

		 * is very wrong. Possibly a local user is trying to DoS the

		 * box by issuing long-running calls and SIGKILL'ing them. If

		 * we get to 2^16 mids then we're in big trouble as this

		 * function could loop forever.

		 *

		 * Go ahead and assign out the mid in this situation, but force

		 * an eventual reconnect to clean out the pending_mid_q.

		 */

		if (num_mids > 32768)

			server->tcpStatus = CifsNeedReconnect;



		if (!collision) {

			mid = (__u64)cur_mid;

			server->CurrentMid = mid;

			break;

		}

		cur_mid++;

	}

	spin_unlock(&GlobalMid_Lock);

	return mid;

}



/* NB: MID can not be set if treeCon not passed in, in that

   case it is responsbility of caller to set the mid */

void
@@ -334,7 +247,7 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , 


			/* Uid is not converted */

			buffer->Uid = treeCon->ses->Suid;

			buffer->Mid = GetNextMid(treeCon->ses->server);

			buffer->Mid = get_next_mid(treeCon->ses->server);

		}

		if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)

			buffer->Flags2 |= SMBFLG2_DFS;