# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.570   -> 1.571  
#	            fs/bio.c	1.27    -> 1.28   
#	 include/linux/bio.h	1.20    -> 1.21   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/09/20	axboe@burns.home.kernel.dk	1.571
# add bio_get_nr_vecs(), returns approximate number of pages that can
# be fitted into a bio for this target
# --------------------------------------------
#
diff -Nru a/fs/bio.c b/fs/bio.c
--- a/fs/bio.c	Fri Sep 20 09:22:09 2002
+++ b/fs/bio.c	Fri Sep 20 09:22:09 2002
@@ -322,6 +322,29 @@
 }
 
 /**
+ *	bio_get_nr_vecs		- return approx number of vecs
+ *	@bdev:  I/O target
+ *
+ *	Return the approximate number of pages we can send to this target.
+ *	There's no guarentee that you will be able to fit this number of pages
+ *	into a bio, it does not account for dynamic restrictions that vary
+ *	on offset.
+ */
+int bio_get_nr_vecs(struct block_device *bdev)
+{
+	request_queue_t *q = bdev_get_queue(bdev);
+	int nr_pages;
+
+	nr_pages = q->max_sectors >> (PAGE_SHIFT - 9);
+	if (nr_pages > q->max_phys_segments)
+		nr_pages = q->max_phys_segments;
+	if (nr_pages > q->max_hw_segments)
+		nr_pages = q->max_hw_segments;
+
+	return nr_pages;
+}
+
+/**
  *	bio_add_page	-	attempt to add page to bio
  *	@bio: destination bio
  *	@page: page to add
@@ -635,3 +658,4 @@
 EXPORT_SYMBOL(bio_phys_segments);
 EXPORT_SYMBOL(bio_hw_segments);
 EXPORT_SYMBOL(bio_add_page);
+EXPORT_SYMBOL(bio_get_nr_vecs);
diff -Nru a/include/linux/bio.h b/include/linux/bio.h
--- a/include/linux/bio.h	Fri Sep 20 09:22:09 2002
+++ b/include/linux/bio.h	Fri Sep 20 09:22:09 2002
@@ -206,6 +206,7 @@
 extern inline void bio_init(struct bio *);
 
 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
+extern int bio_get_nr_vecs(struct block_device *);
 
 #ifdef CONFIG_HIGHMEM
 /*