From 4bb9240e6350ec3e176decc8383082b188265fa8 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 24 Feb 2019 05:36:46 +0000
Subject: [PATCH] vdisk_fileio, async mode: Switch from kvec to bvec

This patch does not change any functionality.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7985 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_vdisk.c | 47 +++++++++++++++---------------
 1 file changed, 24 insertions(+), 23 deletions(-)

diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index b5baa00a3..4494720c8 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -266,9 +266,9 @@ struct vdisk_cmd_params {
 			struct iovec small_iv[4];
 		} sync;
 		struct {
-			struct kiocb iocb;
-			struct kvec  *kvec;
-			struct kvec small_kvec[4];
+			struct kiocb	iocb;
+			struct bio_vec	*bvec;
+			struct bio_vec	small_bvec[4];
 		} async;
 	};
 	struct scst_cmd *cmd;
@@ -3192,20 +3192,20 @@ static bool do_fileio_async(const struct vdisk_cmd_params *p)
 	}
 }
 
-static bool vdisk_alloc_kvec(struct scst_cmd *cmd, struct vdisk_cmd_params *p)
+static bool vdisk_alloc_bvec(struct scst_cmd *cmd, struct vdisk_cmd_params *p)
 {
 	int n;
 
 	n = scst_get_buf_count(cmd);
-	if (n <= ARRAY_SIZE(p->async.small_kvec)) {
-		p->async.kvec = &p->async.small_kvec[0];
+	if (n <= ARRAY_SIZE(p->async.small_bvec)) {
+		p->async.bvec = &p->async.small_bvec[0];
 		return true;
 	}
 
-	p->async.kvec = kmalloc_array(n, sizeof(*p->async.kvec),
+	p->async.bvec = kmalloc_array(n, sizeof(*p->async.bvec),
 				      cmd->cmd_gfp_mask);
-	if (p->async.kvec == NULL) {
-		PRINT_ERROR("Unable to allocate kvecv (%d)", n);
+	if (p->async.bvec == NULL) {
+		PRINT_ERROR("Unable to allocate bvec (%d)", n);
 		return false;
 	}
 
@@ -3253,10 +3253,10 @@ static enum compl_status_e fileio_exec_async(struct vdisk_cmd_params *p)
 	struct file *fd = virt_dev->fd;
 	struct iov_iter iter = { };
 	ssize_t length, total = 0;
-	struct kvec *kvec;
+	struct bio_vec *bvec;
+	struct page *page;
 	struct kiocb *iocb = &p->async.iocb;
-	uint8_t *address;
-	int dir, ret;
+	int offset, sg_cnt = 0, dir, ret;
 
 	switch (cmd->data_direction) {
 	case SCST_DATA_READ:
@@ -3270,31 +3270,32 @@ static enum compl_status_e fileio_exec_async(struct vdisk_cmd_params *p)
 		return CMD_FAILED;
 	}
 
-	if (!vdisk_alloc_kvec(cmd, p)) {
+	if (!vdisk_alloc_bvec(cmd, p)) {
 		scst_set_busy(cmd);
 		return CMD_SUCCEEDED;
 	}
 
 	p->execute_async = true;
 
-	kvec = p->async.kvec;
-	length = scst_get_buf_first(cmd, &address);
+	bvec = p->async.bvec;
+	length = scst_get_sg_page_first(cmd, &page, &offset);
 	while (length) {
-		*kvec++ = (struct kvec){
-			.iov_base = address,
-			.iov_len = length,
+		*bvec++ = (struct bio_vec){
+			.bv_page   = page,
+			.bv_offset = offset,
+			.bv_len    = length,
 		};
 		total += length;
-		length = scst_get_buf_next(cmd, &address);
+		sg_cnt++;
+		length = scst_get_sg_page_next(cmd, &page, &offset);
 	}
 
-	WARN_ON_ONCE(kvec - p->async.kvec != scst_get_buf_count(cmd));
+	WARN_ON_ONCE(sg_cnt != scst_get_buf_count(cmd));
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0)
-	iov_iter_kvec(&iter, dir, p->async.kvec, kvec - p->async.kvec, total);
+	iov_iter_bvec(&iter, dir, p->async.bvec, sg_cnt, total);
 #else
-	iov_iter_kvec(&iter, ITER_KVEC | dir, p->async.kvec,
-		      kvec - p->async.kvec, total);
+	iov_iter_bvec(&iter, ITER_BVEC | dir, p->async.bvec, sg_cnt, total);
 #endif
 	*iocb = (struct kiocb) {
 		.ki_pos = p->loff,