block: remove struct request buffer member

This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.

Convert old style drivers to just use bio_data().

For the discard payload use case, just reference the page
in the bio.

Signed-off-by: Jens Axboe <axboe@fb.com>

20 files changed, 49 insertions, 56 deletions

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 748dea4f34d..758da2287d9 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1406,7 +1406,7 @@ next_segment:
 
 		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
 		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
-		data = rq->buffer + 512 * cnt;
+		data = bio_data(rq->bio) + 512 * cnt;
 #ifdef DEBUG
 		printk("access to track %d, sector %d, with buffer at "
 		       "0x%08lx\n", track, sector, data);
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 96b629e1f0c..7e8a55f8917 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -1484,7 +1484,7 @@ repeat:
 	ReqCnt = 0;
 	ReqCmd = rq_data_dir(fd_request);
 	ReqBlock = blk_rq_pos(fd_request);
-	ReqBuffer = fd_request->buffer;
+	ReqBuffer = bio_data(fd_request->bio);
 	setup_req_params( drive );
 	do_fd_action( drive );
 
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 8f5565bf34c..5f69c910c3a 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2351,7 +2351,7 @@ static void rw_interrupt(void)
 	}
 
 	if (CT(COMMAND) != FD_READ ||
-	    raw_cmd->kernel_data == current_req->buffer) {
+	    raw_cmd->kernel_data == bio_data(current_req->bio)) {
 		/* transfer directly from buffer */
 		cont->done(1);
 	} else if (CT(COMMAND) == FD_READ) {
@@ -2640,7 +2640,7 @@ static int make_raw_rw_request(void)
 		raw_cmd->flags &= ~FD_RAW_WRITE;
 		raw_cmd->flags |= FD_RAW_READ;
 		COMMAND = FM_MODE(_floppy, FD_READ);
-	} else if ((unsigned long)current_req->buffer < MAX_DMA_ADDRESS) {
+	} else if ((unsigned long)bio_data(current_req->bio) < MAX_DMA_ADDRESS) {
 		unsigned long dma_limit;
 		int direct, indirect;
 
@@ -2654,13 +2654,13 @@ static int make_raw_rw_request(void)
 		 */
 		max_size = buffer_chain_size();
 		dma_limit = (MAX_DMA_ADDRESS -
-			     ((unsigned long)current_req->buffer)) >> 9;
+			     ((unsigned long)bio_data(current_req->bio))) >> 9;
 		if ((unsigned long)max_size > dma_limit)
 			max_size = dma_limit;
 		/* 64 kb boundaries */
-		if (CROSS_64KB(current_req->buffer, max_size << 9))
+		if (CROSS_64KB(bio_data(current_req->bio), max_size << 9))
 			max_size = (K_64 -
-				    ((unsigned long)current_req->buffer) %
+				    ((unsigned long)bio_data(current_req->bio)) %
 				    K_64) >> 9;
 		direct = transfer_size(ssize, max_sector, max_size) - fsector_t;
 		/*
@@ -2677,7 +2677,7 @@ static int make_raw_rw_request(void)
 		       (DP->read_track & (1 << DRS->probed_format)))))) {
 			max_size = blk_rq_sectors(current_req);
 		} else {
-			raw_cmd->kernel_data = current_req->buffer;
+			raw_cmd->kernel_data = bio_data(current_req->bio);
 			raw_cmd->length = current_count_sectors << 9;
 			if (raw_cmd->length == 0) {
 				DPRINT("%s: zero dma transfer attempted\n", __func__);
@@ -2731,7 +2731,7 @@ static int make_raw_rw_request(void)
 	raw_cmd->length = ((raw_cmd->length - 1) | (ssize - 1)) + 1;
 	raw_cmd->length <<= 9;
 	if ((raw_cmd->length < current_count_sectors << 9) ||
-	    (raw_cmd->kernel_data != current_req->buffer &&
+	    (raw_cmd->kernel_data != bio_data(current_req->bio) &&
 	     CT(COMMAND) == FD_WRITE &&
 	     (aligned_sector_t + (raw_cmd->length >> 9) > buffer_max ||
 	      aligned_sector_t < buffer_min)) ||
@@ -2739,7 +2739,7 @@ static int make_raw_rw_request(void)
 	    raw_cmd->length <= 0 || current_count_sectors <= 0) {
 		DPRINT("fractionary current count b=%lx s=%lx\n",
 		       raw_cmd->length, current_count_sectors);
-		if (raw_cmd->kernel_data != current_req->buffer)
+		if (raw_cmd->kernel_data != bio_data(current_req->bio))
 			pr_info("addr=%d, length=%ld\n",
 				(int)((raw_cmd->kernel_data -
 				       floppy_track_buffer) >> 9),
@@ -2756,7 +2756,7 @@ static int make_raw_rw_request(void)
 		return 0;
 	}
 
-	if (raw_cmd->kernel_data != current_req->buffer) {
+	if (raw_cmd->kernel_data != bio_data(current_req->bio)) {
 		if (raw_cmd->kernel_data < floppy_track_buffer ||
 		    current_count_sectors < 0 ||
 		    raw_cmd->length < 0 ||
diff --git a/drivers/block/hd.c b/drivers/block/hd.c
index bf397bf108b..8a290c08262 100644
--- a/drivers/block/hd.c
+++ b/drivers/block/hd.c
@@ -464,11 +464,11 @@ static void read_intr(void)
 
 ok_to_read:
 	req = hd_req;
-	insw(HD_DATA, req->buffer, 256);
+	insw(HD_DATA, bio_data(req->bio), 256);
 #ifdef DEBUG
 	printk("%s: read: sector %ld, remaining = %u, buffer=%p\n",
 	       req->rq_disk->disk_name, blk_rq_pos(req) + 1,
-	       blk_rq_sectors(req) - 1, req->buffer+512);
+	       blk_rq_sectors(req) - 1, bio_data(req->bio)+512);
 #endif
 	if (hd_end_request(0, 512)) {
 		SET_HANDLER(&read_intr);
@@ -505,7 +505,7 @@ static void write_intr(void)
 ok_to_write:
 	if (hd_end_request(0, 512)) {
 		SET_HANDLER(&write_intr);
-		outsw(HD_DATA, req->buffer, 256);
+		outsw(HD_DATA, bio_data(req->bio), 256);
 		return;
 	}
 
@@ -624,7 +624,7 @@ repeat:
 	printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
 		req->rq_disk->disk_name,
 		req_data_dir(req) == READ ? "read" : "writ",
-		cyl, head, sec, nsect, req->buffer);
+		cyl, head, sec, nsect, bio_data(req->bio));
 #endif
 	if (req->cmd_type == REQ_TYPE_FS) {
 		switch (rq_data_dir(req)) {
@@ -643,7 +643,7 @@ repeat:
 				bad_rw_intr();
 				goto repeat;
 			}
-			outsw(HD_DATA, req->buffer, 256);
+			outsw(HD_DATA, bio_data(req->bio), 256);
 			break;
 		default:
 			printk("unknown hd-command\n");
diff --git a/drivers/block/mg_disk.c b/drivers/block/mg_disk.c
index eb59b124136..e352cac707e 100644
--- a/drivers/block/mg_disk.c
+++ b/drivers/block/mg_disk.c
@@ -479,7 +479,7 @@ static unsigned int mg_out(struct mg_host *host,
 
 static void mg_read_one(struct mg_host *host, struct request *req)
 {
-	u16 *buff = (u16 *)req->buffer;
+	u16 *buff = (u16 *)bio_data(req->bio);
 	u32 i;
 
 	for (i = 0; i < MG_SECTOR_SIZE >> 1; i++)
@@ -496,7 +496,7 @@ static void mg_read(struct request *req)
 		mg_bad_rw_intr(host);
 
 	MG_DBG("requested %d sects (from %ld), buffer=0x%p\n",
-	       blk_rq_sectors(req), blk_rq_pos(req), req->buffer);
+	       blk_rq_sectors(req), blk_rq_pos(req), bio_data(req->bio));
 
 	do {
 		if (mg_wait(host, ATA_DRQ,
@@ -514,7 +514,7 @@ static void mg_read(struct request *req)
 
 static void mg_write_one(struct mg_host *host, struct request *req)
 {
-	u16 *buff = (u16 *)req->buffer;
+	u16 *buff = (u16 *)bio_data(req->bio);
 	u32 i;
 
 	for (i = 0; i < MG_SECTOR_SIZE >> 1; i++)
@@ -534,7 +534,7 @@ static void mg_write(struct request *req)
 	}
 
 	MG_DBG("requested %d sects (from %ld), buffer=0x%p\n",
-	       rem, blk_rq_pos(req), req->buffer);
+	       rem, blk_rq_pos(req), bio_data(req->bio));
 
 	if (mg_wait(host, ATA_DRQ,
 		    MG_TMAX_WAIT_WR_DRQ) != MG_ERR_NONE) {
@@ -585,7 +585,7 @@ ok_to_read:
 	mg_read_one(host, req);
 
 	MG_DBG("sector %ld, remaining=%ld, buffer=0x%p\n",
-	       blk_rq_pos(req), blk_rq_sectors(req) - 1, req->buffer);
+	       blk_rq_pos(req), blk_rq_sectors(req) - 1, bio_data(req->bio));
 
 	/* send read confirm */
 	outb(MG_CMD_RD_CONF, (unsigned long)host->dev_base + MG_REG_COMMAND);
@@ -624,7 +624,7 @@ ok_to_write:
 		/* write 1 sector and set handler if remains */
 		mg_write_one(host, req);
 		MG_DBG("sector %ld, remaining=%ld, buffer=0x%p\n",
-		       blk_rq_pos(req), blk_rq_sectors(req), req->buffer);
+		       blk_rq_pos(req), blk_rq_sectors(req), bio_data(req->bio));
 		host->mg_do_intr = mg_write_intr;
 		mod_timer(&host->timer, jiffies + 3 * HZ);
 	}
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index e76bdc074db..719cb1bc164 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -747,7 +747,7 @@ static void do_pcd_request(struct request_queue * q)
 			pcd_current = cd;
 			pcd_sector = blk_rq_pos(pcd_req);
 			pcd_count = blk_rq_cur_sectors(pcd_req);
-			pcd_buf = pcd_req->buffer;
+			pcd_buf = bio_data(pcd_req->bio);
 			pcd_busy = 1;
 			ps_set_intr(do_pcd_read, NULL, 0, nice);
 			return;
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index 19ad8f0c83e..fea7e76a00d 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -454,7 +454,7 @@ static enum action do_pd_io_start(void)
 		if (pd_block + pd_count > get_capacity(pd_req->rq_disk))
 			return Fail;
 		pd_run = blk_rq_sectors(pd_req);
-		pd_buf = pd_req->buffer;
+		pd_buf = bio_data(pd_req->bio);
 		pd_retries = 0;
 		if (pd_cmd == READ)
 			return do_pd_read_start();
@@ -485,7 +485,7 @@ static int pd_next_buf(void)
 	spin_lock_irqsave(&pd_lock, saved_flags);
 	__blk_end_request_cur(pd_req, 0);
 	pd_count = blk_rq_cur_sectors(pd_req);
-	pd_buf = pd_req->buffer;
+	pd_buf = bio_data(pd_req->bio);
 	spin_unlock_irqrestore(&pd_lock, saved_flags);
 	return 0;
 }
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index f5c86d523ba..9a15fd3c934 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -795,7 +795,7 @@ repeat:
 	}
 
 	pf_cmd = rq_data_dir(pf_req);
-	pf_buf = pf_req->buffer;
+	pf_buf = bio_data(pf_req->bio);
 	pf_retries = 0;
 
 	pf_busy = 1;
@@ -827,7 +827,7 @@ static int pf_next_buf(void)
 		if (!pf_req)
 			return 1;
 		pf_count = blk_rq_cur_sectors(pf_req);
-		pf_buf = pf_req->buffer;
+		pf_buf = bio_data(pf_req->bio);
 	}
 	return 0;
 }
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index a69dd93d1bd..36bcedfd930 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -563,7 +563,6 @@ skd_prep_discard_cdb(struct skd_scsi_request *scsi_req,
 
 	req = skreq->req;
 	blk_add_request_payload(req, page, len);
-	req->buffer = buf;
 }
 
 static void skd_request_fn_not_online(struct request_queue *q);
@@ -856,10 +855,10 @@ static void skd_end_request(struct skd_device *skdev,
 
 	if ((io_flags & REQ_DISCARD) &&
 		(skreq->discard_page == 1)) {
+		struct bio *bio = req->bio;
 		pr_debug("%s:%s:%d, free the page!",
 			 skdev->name, __func__, __LINE__);
-		free_page((unsigned long)req->buffer);
-		req->buffer = NULL;
+		__free_page(bio->bi_io_vec->bv_page);
 	}
 
 	if (unlikely(error)) {
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index b02d53a399f..6b44bbe528b 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -549,7 +549,7 @@ static void redo_fd_request(struct request_queue *q)
 		case READ:
 			err = floppy_read_sectors(fs, blk_rq_pos(req),
 						  blk_rq_cur_sectors(req),
-						  req->buffer);
+						  bio_data(req->bio));
 			break;
 		}
 	done:
diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index c74f7b56e7c..523ee8fd4c1 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -342,7 +342,7 @@ static void start_request(struct floppy_state *fs)
 		swim3_dbg("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%u buf=%p\n",
 			  req->rq_disk->disk_name, req->cmd,
 			  (long)blk_rq_pos(req), blk_rq_sectors(req),
-			  req->buffer);
+			  bio_data(req->bio));
 		swim3_dbg("           errors=%d current_nr_sectors=%u\n",
 			  req->errors, blk_rq_cur_sectors(req));
 #endif
@@ -479,11 +479,11 @@ static inline void setup_transfer(struct floppy_state *fs)
 		/* Set up 3 dma commands: write preamble, data, postamble */
 		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
 		++cp;
-		init_dma(cp, OUTPUT_MORE, req->buffer, 512);
+		init_dma(cp, OUTPUT_MORE, bio_data(req->bio), 512);
 		++cp;
 		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
 	} else {
-		init_dma(cp, INPUT_LAST, req->buffer, n * 512);
+		init_dma(cp, INPUT_LAST, bio_data(req->bio), n * 512);
 	}
 	++cp;
 	out_le16(&cp->command, DBDMA_STOP);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index efe1b476173..283a30e8828 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -612,10 +612,10 @@ static void do_blkif_request(struct request_queue *rq)
 		}
 
 		pr_debug("do_blk_req %p: cmd %p, sec %lx, "
-			 "(%u/%u) buffer:%p [%s]\n",
+			 "(%u/%u) [%s]\n",
 			 req, req->cmd, (unsigned long)blk_rq_pos(req),
 			 blk_rq_cur_sectors(req), blk_rq_sectors(req),
-			 req->buffer, rq_data_dir(req) ? "write" : "read");
+			 rq_data_dir(req) ? "write" : "read");
 
 		if (blkif_queue_request(req)) {
 			blk_requeue_request(rq, req);
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c
index 1393b8871a2..ab3ea62e5df 100644
--- a/drivers/block/xsysace.c
+++ b/drivers/block/xsysace.c
@@ -661,7 +661,7 @@ static void ace_fsm_dostate(struct ace_device *ace)
 			rq_data_dir(req));
 
 		ace->req = req;
-		ace->data_ptr = req->buffer;
+		ace->data_ptr = bio_data(req->bio);
 		ace->data_count = blk_rq_cur_sectors(req) * ACE_BUF_PER_SECTOR;
 		ace_out32(ace, ACE_MPULBA, blk_rq_pos(req) & 0x0FFFFFFF);
 
@@ -733,7 +733,7 @@ static void ace_fsm_dostate(struct ace_device *ace)
 			 *      blk_rq_sectors(ace->req),
 			 *      blk_rq_cur_sectors(ace->req));
 			 */
-			ace->data_ptr = ace->req->buffer;
+			ace->data_ptr = bio_data(ace->req->bio);
 			ace->data_count = blk_rq_cur_sectors(ace->req) * 16;
 			ace_fsm_yieldirq(ace);
 			break;
diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index 27de5046708..968f9e52eff 100644
--- a/drivers/block/z2ram.c
+++ b/drivers/block/z2ram.c
@@ -87,13 +87,15 @@ static void do_z2_request(struct request_queue *q)
 		while (len) {
 			unsigned long addr = start & Z2RAM_CHUNKMASK;
 			unsigned long size = Z2RAM_CHUNKSIZE - addr;
+			void *buffer = bio_data(req->bio);
+
 			if (len < size)
 				size = len;
 			addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
 			if (rq_data_dir(req) == READ)
-				memcpy(req->buffer, (char *)addr, size);
+				memcpy(buffer, (char *)addr, size);
 			else
-				memcpy((char *)addr, req->buffer, size);
+				memcpy((char *)addr, buffer, size);
 			start += size;
 			len -= size;
 		}
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 16f69be820c..ee880382e3b 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -188,10 +188,9 @@ static ide_startstop_t ide_do_rw_disk(ide_drive_t *drive, struct request *rq,
 
 	ledtrig_ide_activity();
 
-	pr_debug("%s: %sing: block=%llu, sectors=%u, buffer=0x%08lx\n",
+	pr_debug("%s: %sing: block=%llu, sectors=%u\n",
 		 drive->name, rq_data_dir(rq) == READ ? "read" : "writ",
-		 (unsigned long long)block, blk_rq_sectors(rq),
-		 (unsigned long)rq->buffer);
+		 (unsigned long long)block, blk_rq_sectors(rq));
 
 	if (hwif->rw_disk)
 		hwif->rw_disk(drive, rq);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 455e6491649..6a71bc7c913 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1544,7 +1544,6 @@ static int setup_clone(struct request *clone, struct request *rq,
 	clone->cmd = rq->cmd;
 	clone->cmd_len = rq->cmd_len;
 	clone->sense = rq->sense;
-	clone->buffer = rq->buffer;
 	clone->end_io = end_clone_request;
 	clone->end_io_data = tio;
 
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 0b2ccb68c0d..4dbfaee9aa9 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -82,8 +82,7 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 
 	block = blk_rq_pos(req) << 9 >> tr->blkshift;
 	nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
-
-	buf = req->buffer;
+	buf = bio_data(req->bio);
 
 	if (req->cmd_type != REQ_TYPE_FS)
 		return -EIO;
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 7ff473c871a..ee774ba3728 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -253,7 +253,7 @@ static int do_ubiblock_request(struct ubiblock *dev, struct request *req)
 	 * flash access anyway.
 	 */
 	mutex_lock(&dev->dev_mutex);
-	ret = ubiblock_read(dev, req->buffer, sec, len);
+	ret = ubiblock_read(dev, bio_data(req->bio), sec, len);
 	mutex_unlock(&dev->dev_mutex);
 
 	return ret;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0f3bddcb6b1..3cc82d3dec7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1018,8 +1018,6 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
 		return BLKPREP_DEFER;
 	}
 
-	req->buffer = NULL;
-
 	/* 
 	 * Next, walk the list, and fill in the addresses and sizes of
 	 * each segment.
@@ -1156,7 +1154,6 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 		BUG_ON(blk_rq_bytes(req));
 
 		memset(&cmd->sdb, 0, sizeof(cmd->sdb));
-		req->buffer = NULL;
 	}
 
 	cmd->cmd_len = req->cmd_len;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index efcbcd18286..06d154d20fa 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -739,14 +739,11 @@ static int sd_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
 
 	blk_add_request_payload(rq, page, len);
 	ret = scsi_setup_blk_pc_cmnd(sdp, rq);
-	rq->buffer = page_address(page);
 	rq->__data_len = nr_bytes;
 
 out:
-	if (ret != BLKPREP_OK) {
+	if (ret != BLKPREP_OK)
 		__free_page(page);
-		rq->buffer = NULL;
-	}
 	return ret;
 }
 
@@ -843,8 +840,9 @@ static void sd_unprep_fn(struct request_queue *q, struct request *rq)
 	struct scsi_cmnd *SCpnt = rq->special;
 
 	if (rq->cmd_flags & REQ_DISCARD) {
-		free_page((unsigned long)rq->buffer);
-		rq->buffer = NULL;
+		struct bio *bio = rq->bio;
+
+		__free_page(bio->bi_io_vec->bv_page);
 	}
 	if (SCpnt->cmnd != rq->cmd) {
 		mempool_free(SCpnt->cmnd, sd_cdb_pool);