cifs: teach smb_send_rqst how to handle arrays of pages (97bc00b3) · Commits · 戴 / test

fs/cifs/transport.c

+54 −2

Original line number	Original line	Diff line number	Diff line
	@@ -28,6 +28,7 @@
	#include <linux/delay.h>		#include <linux/delay.h>
	#include <linux/freezer.h>		#include <linux/freezer.h>
	#include <linux/tcp.h>		#include <linux/tcp.h>
			#include <linux/highmem.h>
	#include <asm/uaccess.h>		#include <asm/uaccess.h>
	#include <asm/processor.h>		#include <asm/processor.h>
	#include <linux/mempool.h>		#include <linux/mempool.h>
	@@ -240,6 +241,38 @@ smb_send_kvec(struct TCP_Server_Info server, struct kvec iov, size_t n_vec,
	return rc;		return rc;
	}		}

			/**
			* rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
			* @rqst: pointer to smb_rqst
			* @idx: index into the array of the page
			* @iov: pointer to struct kvec that will hold the result
			*
			* Helper function to convert a slot in the rqst->rq_pages array into a kvec.
			* The page will be kmapped and the address placed into iov_base. The length
			* will then be adjusted according to the ptailoff.
			*/
			static void
			cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
			struct kvec *iov)
			{
			/*
			* FIXME: We could avoid this kmap altogether if we used
			* kernel_sendpage instead of kernel_sendmsg. That will only
			* work if signing is disabled though as sendpage inlines the
			* page directly into the fraglist. If userspace modifies the
			* page after we calculate the signature, then the server will
			* reject it and may break the connection. kernel_sendmsg does
			* an extra copy of the data and avoids that issue.
			*/
			iov->iov_base = kmap(rqst->rq_pages[idx]);

			/* if last page, don't send beyond this offset into page */
			if (idx == (rqst->rq_npages - 1))
			iov->iov_len = rqst->rq_tailsz;
			else
			iov->iov_len = rqst->rq_pagesz;
			}

	static int		static int
	smb_send_rqst(struct TCP_Server_Info server, struct smb_rqst rqst)		smb_send_rqst(struct TCP_Server_Info server, struct smb_rqst rqst)
	{		{
	@@ -247,7 +280,8 @@ smb_send_rqst(struct TCP_Server_Info server, struct smb_rqst rqst)
	struct kvec *iov = rqst->rq_iov;		struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;		int n_vec = rqst->rq_nvec;
	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);		unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
	size_t total_len;		unsigned int i;
			size_t total_len = 0, sent;
	struct socket *ssocket = server->ssocket;		struct socket *ssocket = server->ssocket;
	int val = 1;		int val = 1;

	@@ -258,8 +292,26 @@ smb_send_rqst(struct TCP_Server_Info server, struct smb_rqst rqst)
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,		kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
	(char *)&val, sizeof(val));		(char *)&val, sizeof(val));

	rc = smb_send_kvec(server, iov, n_vec, &total_len);		rc = smb_send_kvec(server, iov, n_vec, &sent);
			if (rc < 0)
			goto uncork;

			total_len += sent;

			/* now walk the page array and send each page in it */
			for (i = 0; i < rqst->rq_npages; i++) {
			struct kvec p_iov;

			cifs_rqst_page_to_kvec(rqst, i, &p_iov);
			rc = smb_send_kvec(server, &p_iov, 1, &sent);
			kunmap(rqst->rq_pages[i]);
			if (rc < 0)
			break;

			total_len += sent;
			}

			uncork:
	/* uncork it */		/* uncork it */
	val = 0;		val = 0;
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,		kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,

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