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Commit 2a37ef94 authored by Jeff Layton's avatar Jeff Layton
Browse files

cifs: move buffer pointers into TCP_Server_Info 



We have several functions that need to access these pointers. Currently
that's done with a lot of double pointer passing. Instead, move them
into the TCP_Server_Info and simplify the handling.

Reviewed-and-Tested-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
parent ffc00e27

fs/cifs/cifsglob.h

+4 −0
Original line number Diff line number Diff line
@@ -291,9 +291,13 @@ struct TCP_Server_Info { 
	bool	sec_kerberosu2u;	/* supports U2U Kerberos */

	bool	sec_kerberos;		/* supports plain Kerberos */

	bool	sec_mskerberos;		/* supports legacy MS Kerberos */

	bool	large_buf;		/* is current buffer large? */

	struct delayed_work	echo; /* echo ping workqueue job */

	struct kvec *iov;	/* reusable kvec array for receives */

	unsigned int nr_iov;	/* number of kvecs in array */

	char	*smallbuf;	/* pointer to current "small" buffer */

	char	*bigbuf;	/* pointer to current "big" buffer */

	unsigned int total_read; /* total amount of data read in this pass */

#ifdef CONFIG_CIFS_FSCACHE

	struct fscache_cookie   *fscache; /* client index cache cookie */

#endif

fs/cifs/connect.c

+46 −55
Original line number Diff line number Diff line
@@ -320,27 +320,24 @@ cifs_echo_request(struct work_struct *work) 
}



static bool

allocate_buffers(char **bigbuf, char **smallbuf, unsigned int size,

		 bool is_large_buf)

allocate_buffers(struct TCP_Server_Info *server)

{

	char *bbuf = *bigbuf, *sbuf = *smallbuf;



	if (bbuf == NULL) {

		bbuf = (char *)cifs_buf_get();

		if (!bbuf) {

	if (!server->bigbuf) {

		server->bigbuf = (char *)cifs_buf_get();

		if (!server->bigbuf) {

			cERROR(1, "No memory for large SMB response");

			msleep(3000);

			/* retry will check if exiting */

			return false;

		}

	} else if (is_large_buf) {

	} else if (server->large_buf) {

		/* we are reusing a dirty large buf, clear its start */

		memset(bbuf, 0, size);

		memset(server->bigbuf, 0, sizeof(struct smb_hdr));

	}



	if (sbuf == NULL) {

		sbuf = (char *)cifs_small_buf_get();

		if (!sbuf) {

	if (!server->smallbuf) {

		server->smallbuf = (char *)cifs_small_buf_get();

		if (!server->smallbuf) {

			cERROR(1, "No memory for SMB response");

			msleep(1000);

			/* retry will check if exiting */
@@ -349,12 +346,9 @@ allocate_buffers(char **bigbuf, char **smallbuf, unsigned int size, 
		/* beginning of smb buffer is cleared in our buf_get */

	} else {

		/* if existing small buf clear beginning */

		memset(sbuf, 0, size);

		memset(server->smallbuf, 0, sizeof(struct smb_hdr));

	}



	*bigbuf = bbuf;

	*smallbuf = sbuf;



	return true;

}
@@ -576,7 +570,7 @@ dequeue_mid(struct mid_q_entry *mid, int malformed) 


static struct mid_q_entry *

find_cifs_mid(struct TCP_Server_Info *server, struct smb_hdr *buf,

	      int malformed, bool is_large_buf, char **bigbuf)

	      int malformed)

{

	struct mid_q_entry *mid = NULL;
@@ -596,19 +590,27 @@ find_cifs_mid(struct TCP_Server_Info *server, struct smb_hdr *buf, 
			mid->multiEnd = true;

			goto multi_t2_fnd;

		}

		if (!is_large_buf) {

		if (!server->large_buf) {

			/*FIXME: switch to already allocated largebuf?*/

			cERROR(1, "1st trans2 resp needs bigbuf");

		} else {

			/* Have first buffer */

			mid->resp_buf = buf;

			mid->largeBuf = true;

			*bigbuf = NULL;

			server->bigbuf = NULL;

		}

		return mid;

	}

	mid->resp_buf = buf;

	mid->largeBuf = is_large_buf;

	mid->largeBuf = server->large_buf;

	/* Was previous buf put in mpx struct for multi-rsp? */

	if (!mid->multiRsp) {

		/* smb buffer will be freed by user thread */

		if (server->large_buf)

			server->bigbuf = NULL;

		else

			server->smallbuf = NULL;

	}

multi_t2_fnd:

	dequeue_mid(mid, malformed);

	return mid;
@@ -715,12 +717,11 @@ cifs_demultiplex_thread(void *p) 
{

	int length;

	struct TCP_Server_Info *server = p;

	unsigned int pdu_length, total_read;

	char *buf = NULL, *bigbuf = NULL, *smallbuf = NULL;

	unsigned int pdu_length;

	char *buf = NULL;

	struct smb_hdr *smb_buffer = NULL;

	struct task_struct *task_to_wake = NULL;

	struct mid_q_entry *mid_entry;

	bool isLargeBuf = false;



	current->flags |= PF_MEMALLOC;

	cFYI(1, "Demultiplex PID: %d", task_pid_nr(current));
@@ -735,19 +736,18 @@ cifs_demultiplex_thread(void *p) 
		if (try_to_freeze())

			continue;



		if (!allocate_buffers(&bigbuf, &smallbuf,

				      sizeof(struct smb_hdr), isLargeBuf))

		if (!allocate_buffers(server))

			continue;



		isLargeBuf = false;

		smb_buffer = (struct smb_hdr *)smallbuf;

		buf = smallbuf;

		server->large_buf = false;

		smb_buffer = (struct smb_hdr *)server->smallbuf;

		buf = server->smallbuf;

		pdu_length = 4; /* enough to get RFC1001 header */



		length = read_from_socket(server, buf, pdu_length);

		if (length < 0)

			continue;

		total_read = length;

		server->total_read = length;



		/*

		 * The right amount was read from socket - 4 bytes,
@@ -773,7 +773,7 @@ cifs_demultiplex_thread(void *p) 
					  sizeof(struct smb_hdr) - 1 - 4);

		if (length < 0)

			continue;

		total_read += length;

		server->total_read += length;



		if (pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {

			cERROR(1, "SMB response too long (%u bytes)",
@@ -785,10 +785,11 @@ cifs_demultiplex_thread(void *p) 


		/* else length ok */

		if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {

			isLargeBuf = true;

			memcpy(bigbuf, smallbuf, total_read);

			smb_buffer = (struct smb_hdr *)bigbuf;

			buf = bigbuf;

			server->large_buf = true;

			memcpy(server->bigbuf, server->smallbuf,

			       server->total_read);

			smb_buffer = (struct smb_hdr *)server->bigbuf;

			buf = server->bigbuf;

		}



		/* now read the rest */
@@ -797,9 +798,9 @@ cifs_demultiplex_thread(void *p) 
				  pdu_length - sizeof(struct smb_hdr) + 1 + 4);

		if (length < 0)

			continue;

		total_read += length;

		server->total_read += length;



		dump_smb(smb_buffer, total_read);

		dump_smb(smb_buffer, server->total_read);



		/*

		 * We know that we received enough to get to the MID as we
@@ -810,27 +811,17 @@ cifs_demultiplex_thread(void *p) 
		 * 48 bytes is enough to display the header and a little bit

		 * into the payload for debugging purposes.

		 */

		length = checkSMB(smb_buffer, smb_buffer->Mid, total_read);

		length = checkSMB(smb_buffer, smb_buffer->Mid,

				  server->total_read);

		if (length != 0)

			cifs_dump_mem("Bad SMB: ", buf,

				      min_t(unsigned int, total_read, 48));

				min_t(unsigned int, server->total_read, 48));



		server->lstrp = jiffies;



		mid_entry = find_cifs_mid(server, smb_buffer, length,

					  isLargeBuf, &bigbuf);

		mid_entry = find_cifs_mid(server, smb_buffer, length);

		if (mid_entry != NULL) {

			if (mid_entry->multiRsp && !mid_entry->multiEnd)

				continue;



			/* Was previous buf put in mpx struct for multi-rsp? */

			if (!mid_entry->multiRsp) {

				/* smb buffer will be freed by user thread */

				if (isLargeBuf)

					bigbuf = NULL;

				else

					smallbuf = NULL;

			}

			if (!mid_entry->multiRsp || mid_entry->multiEnd)

				mid_entry->callback(mid_entry);

		} else if (length != 0) {

			/* response sanity checks failed */
@@ -849,9 +840,9 @@ cifs_demultiplex_thread(void *p) 
	} /* end while !EXITING */



	/* buffer usually freed in free_mid - need to free it here on exit */

	cifs_buf_release(bigbuf);

	if (smallbuf) /* no sense logging a debug message if NULL */

		cifs_small_buf_release(smallbuf);

	cifs_buf_release(server->bigbuf);

	if (server->smallbuf) /* no sense logging a debug message if NULL */

		cifs_small_buf_release(server->smallbuf);



	task_to_wake = xchg(&server->tsk, NULL);

	clean_demultiplex_info(server);