1 files changed, 58 insertions, 198 deletions

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 8226d52504d0..b2afbc7bcb6b 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -134,7 +134,6 @@ enum {
 struct idetape_bh {
 	u32 b_size;
 	atomic_t b_count;
-	struct idetape_bh *b_reqnext;
 	char *b_data;
 };
 
@@ -228,10 +227,6 @@ typedef struct ide_tape_obj {
 	char *b_data;
 	int b_count;
 
-	int pages_per_buffer;
-	/* Wasted space in each stage */
-	int excess_bh_size;
-
 	/* Measures average tape speed */
 	unsigned long avg_time;
 	int avg_size;
@@ -303,9 +298,7 @@ static int idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 	struct idetape_bh *bh = pc->bh;
 	int count;
 
-	while (bcount) {
-		if (bh == NULL)
-			break;
+	if (bcount && bh) {
 		count = min(
 			(unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
 			bcount);
@@ -313,15 +306,10 @@ static int idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 					atomic_read(&bh->b_count), count);
 		bcount -= count;
 		atomic_add(count, &bh->b_count);
-		if (atomic_read(&bh->b_count) == bh->b_size) {
-			bh = bh->b_reqnext;
-			if (bh)
-				atomic_set(&bh->b_count, 0);
-		}
+		if (atomic_read(&bh->b_count) == bh->b_size)
+			pc->bh = NULL;
 	}
 
-	pc->bh = bh;
-
 	return bcount;
 }
 
@@ -331,22 +319,14 @@ static int idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 	struct idetape_bh *bh = pc->bh;
 	int count;
 
-	while (bcount) {
-		if (bh == NULL)
-			break;
+	if (bcount && bh) {
 		count = min((unsigned int)pc->b_count, (unsigned int)bcount);
 		drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
 		bcount -= count;
 		pc->b_data += count;
 		pc->b_count -= count;
-		if (!pc->b_count) {
-			bh = bh->b_reqnext;
-			pc->bh = bh;
-			if (bh) {
-				pc->b_data = bh->b_data;
-				pc->b_count = atomic_read(&bh->b_count);
-			}
-		}
+		if (!pc->b_count)
+			pc->bh = NULL;
 	}
 
 	return bcount;
@@ -355,24 +335,20 @@ static int idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
 {
 	struct idetape_bh *bh = pc->bh;
-	int count;
 	unsigned int bcount = pc->xferred;
 
 	if (pc->flags & PC_FLAG_WRITING)
 		return;
-	while (bcount) {
-		if (bh == NULL) {
+	if (bcount) {
+		if (bh == NULL || bcount > bh->b_size) {
 			printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 					__func__);
 			return;
 		}
-		count = min((unsigned int)bh->b_size, (unsigned int)bcount);
-		atomic_set(&bh->b_count, count);
+		atomic_set(&bh->b_count, bcount);
 		if (atomic_read(&bh->b_count) == bh->b_size)
-			bh = bh->b_reqnext;
-		bcount -= count;
+			pc->bh = NULL;
 	}
-	pc->bh = bh;
 }
 
 /*
@@ -439,24 +415,10 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 /* Free data buffers completely. */
 static void ide_tape_kfree_buffer(idetape_tape_t *tape)
 {
-	struct idetape_bh *prev_bh, *bh = tape->merge_bh;
-
-	while (bh) {
-		u32 size = bh->b_size;
-
-		while (size) {
-			unsigned int order = fls(size >> PAGE_SHIFT)-1;
-
-			if (bh->b_data)
-				free_pages((unsigned long)bh->b_data, order);
+	struct idetape_bh *bh = tape->merge_bh;
 
-			size &= (order-1);
-			bh->b_data += (1 << order) * PAGE_SIZE;
-		}
-		prev_bh = bh;
-		bh = bh->b_reqnext;
-		kfree(prev_bh);
-	}
+	kfree(bh->b_data);
+	kfree(bh);
 }
 
 static void ide_tape_handle_dsc(ide_drive_t *);
@@ -861,117 +823,50 @@ out:
 }
 
 /*
- * The function below uses __get_free_pages to allocate a data buffer of size
- * tape->buffer_size (or a bit more). We attempt to combine sequential pages as
- * much as possible.
- *
- * It returns a pointer to the newly allocated buffer, or NULL in case of
- * failure.
+ * It returns a pointer to the newly allocated buffer, or NULL in case
+ * of failure.
  */
 static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,
-						  int full, int clear)
-{
-	struct idetape_bh *prev_bh, *bh, *merge_bh;
-	int pages = tape->pages_per_buffer;
-	unsigned int order, b_allocd;
-	char *b_data = NULL;
-
-	merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
-	bh = merge_bh;
-	if (bh == NULL)
-		goto abort;
-
-	order = fls(pages) - 1;
-	bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order);
-	if (!bh->b_data)
-		goto abort;
-	b_allocd = (1 << order) * PAGE_SIZE;
-	pages &= (order-1);
-
-	if (clear)
-		memset(bh->b_data, 0, b_allocd);
-	bh->b_reqnext = NULL;
-	bh->b_size = b_allocd;
-	atomic_set(&bh->b_count, full ? bh->b_size : 0);
+						  int full)
+{
+	struct idetape_bh *bh;
 
-	while (pages) {
-		order = fls(pages) - 1;
-		b_data = (char *) __get_free_pages(GFP_KERNEL, order);
-		if (!b_data)
-			goto abort;
-		b_allocd = (1 << order) * PAGE_SIZE;
-
-		if (clear)
-			memset(b_data, 0, b_allocd);
-
-		/* newly allocated page frames below buffer header or ...*/
-		if (bh->b_data == b_data + b_allocd) {
-			bh->b_size += b_allocd;
-			bh->b_data -= b_allocd;
-			if (full)
-				atomic_add(b_allocd, &bh->b_count);
-			continue;
-		}
-		/* they are above the header */
-		if (b_data == bh->b_data + bh->b_size) {
-			bh->b_size += b_allocd;
-			if (full)
-				atomic_add(b_allocd, &bh->b_count);
-			continue;
-		}
-		prev_bh = bh;
-		bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
-		if (!bh) {
-			free_pages((unsigned long) b_data, order);
-			goto abort;
-		}
-		bh->b_reqnext = NULL;
-		bh->b_data = b_data;
-		bh->b_size = b_allocd;
-		atomic_set(&bh->b_count, full ? bh->b_size : 0);
-		prev_bh->b_reqnext = bh;
+	bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+	if (!bh)
+		return NULL;
 
-		pages &= (order-1);
+	bh->b_data = kmalloc(tape->buffer_size, GFP_KERNEL);
+	if (!bh->b_data) {
+		kfree(bh);
+		return NULL;
 	}
 
-	bh->b_size -= tape->excess_bh_size;
-	if (full)
-		atomic_sub(tape->excess_bh_size, &bh->b_count);
-	return merge_bh;
-abort:
-	ide_tape_kfree_buffer(tape);
-	return NULL;
+	bh->b_size = tape->buffer_size;
+	atomic_set(&bh->b_count, full ? bh->b_size : 0);
+
+	return bh;
 }
 
 static int idetape_copy_stage_from_user(idetape_tape_t *tape,
 					const char __user *buf, int n)
 {
 	struct idetape_bh *bh = tape->bh;
-	int count;
 	int ret = 0;
 
-	while (n) {
-		if (bh == NULL) {
+	if (n) {
+		if (bh == NULL || n > bh->b_size - atomic_read(&bh->b_count)) {
 			printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 					__func__);
 			return 1;
 		}
-		count = min((unsigned int)
-				(bh->b_size - atomic_read(&bh->b_count)),
-				(unsigned int)n);
 		if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf,
-				count))
+				   n))
 			ret = 1;
-		n -= count;
-		atomic_add(count, &bh->b_count);
-		buf += count;
-		if (atomic_read(&bh->b_count) == bh->b_size) {
-			bh = bh->b_reqnext;
-			if (bh)
-				atomic_set(&bh->b_count, 0);
-		}
+		atomic_add(n, &bh->b_count);
+		if (atomic_read(&bh->b_count) == bh->b_size)
+			tape->bh = NULL;
 	}
-	tape->bh = bh;
+
 	return ret;
 }
 
@@ -979,30 +874,20 @@ static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
 				      int n)
 {
 	struct idetape_bh *bh = tape->bh;
-	int count;
 	int ret = 0;
 
-	while (n) {
-		if (bh == NULL) {
+	if (n) {
+		if (bh == NULL || n > tape->b_count) {
 			printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 					__func__);
 			return 1;
 		}
-		count = min(tape->b_count, n);
-		if  (copy_to_user(buf, tape->b_data, count))
+		if (copy_to_user(buf, tape->b_data, n))
 			ret = 1;
-		n -= count;
-		tape->b_data += count;
-		tape->b_count -= count;
-		buf += count;
-		if (!tape->b_count) {
-			bh = bh->b_reqnext;
-			tape->bh = bh;
-			if (bh) {
-				tape->b_data = bh->b_data;
-				tape->b_count = atomic_read(&bh->b_count);
-			}
-		}
+		tape->b_data += n;
+		tape->b_count -= n;
+		if (!tape->b_count)
+			tape->bh = NULL;
 	}
 	return ret;
 }
@@ -1254,7 +1139,7 @@ static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)
 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 {
 	idetape_tape_t *tape = drive->driver_data;
-	int blocks, min;
+	int blocks;
 	struct idetape_bh *bh;
 
 	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
@@ -1269,31 +1154,16 @@ static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 	if (tape->merge_bh_size) {
 		blocks = tape->merge_bh_size / tape->blk_size;
 		if (tape->merge_bh_size % tape->blk_size) {
-			unsigned int i;
-
+			unsigned int i = tape->blk_size -
+				tape->merge_bh_size % tape->blk_size;
 			blocks++;
-			i = tape->blk_size - tape->merge_bh_size %
-				tape->blk_size;
-			bh = tape->bh->b_reqnext;
-			while (bh) {
-				atomic_set(&bh->b_count, 0);
-				bh = bh->b_reqnext;
-			}
 			bh = tape->bh;
-			while (i) {
-				if (bh == NULL) {
-					printk(KERN_INFO "ide-tape: bug,"
-							 " bh NULL\n");
-					break;
-				}
-				min = min(i, (unsigned int)(bh->b_size -
-						atomic_read(&bh->b_count)));
+			if (bh) {
 				memset(bh->b_data + atomic_read(&bh->b_count),
-						0, min);
-				atomic_add(min, &bh->b_count);
-				i -= min;
-				bh = bh->b_reqnext;
-			}
+				       0, i);
+				atomic_add(i, &bh->b_count);
+			} else
+				printk(KERN_INFO "ide-tape: bug, bh NULL\n");
 		}
 		(void) idetape_add_chrdev_write_request(drive, blocks);
 		tape->merge_bh_size = 0;
@@ -1321,7 +1191,7 @@ static int idetape_init_read(ide_drive_t *drive)
 					 " 0 now\n");
 			tape->merge_bh_size = 0;
 		}
-		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0);
 		if (!tape->merge_bh)
 			return -ENOMEM;
 		tape->chrdev_dir = IDETAPE_DIR_READ;
@@ -1368,23 +1238,18 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 {
 	idetape_tape_t *tape = drive->driver_data;
-	struct idetape_bh *bh;
+	struct idetape_bh *bh = tape->merge_bh;
 	int blocks;
 
 	while (bcount) {
 		unsigned int count;
 
-		bh = tape->merge_bh;
 		count = min(tape->buffer_size, bcount);
 		bcount -= count;
 		blocks = count / tape->blk_size;
-		while (count) {
-			atomic_set(&bh->b_count,
-				   min(count, (unsigned int)bh->b_size));
-			memset(bh->b_data, 0, atomic_read(&bh->b_count));
-			count -= atomic_read(&bh->b_count);
-			bh = bh->b_reqnext;
-		}
+		atomic_set(&bh->b_count, count);
+		memset(bh->b_data, 0, atomic_read(&bh->b_count));
+
 		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,
 				      tape->merge_bh);
 	}
@@ -1596,7 +1461,7 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
 				"should be 0 now\n");
 			tape->merge_bh_size = 0;
 		}
-		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+		tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0);
 		if (!tape->merge_bh)
 			return -ENOMEM;
 		tape->chrdev_dir = IDETAPE_DIR_WRITE;
@@ -1970,7 +1835,7 @@ static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
 	idetape_tape_t *tape = drive->driver_data;
 
 	ide_tape_flush_merge_buffer(drive);
-	tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);
+	tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1);
 	if (tape->merge_bh != NULL) {
 		idetape_pad_zeros(drive, tape->blk_size *
 				(tape->user_bs_factor - 1));
@@ -2201,11 +2066,6 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
 		tape->buffer_size = *ctl * tape->blk_size;
 	}
 	buffer_size = tape->buffer_size;
-	tape->pages_per_buffer = buffer_size / PAGE_SIZE;
-	if (buffer_size % PAGE_SIZE) {
-		tape->pages_per_buffer++;
-		tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE;
-	}
 
 	/* select the "best" DSC read/write polling freq */
 	speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);