X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fblock%2Fbiodoc.txt;h=4dbb8be1c991c3b4049d69ff68c99c12e5f34ce3;hb=b98cb4b7fe0e83238501b48489e46b3e0dce9aaf;hp=8af392fc6ef0e74b115257b5d31bb4345cd09f9f;hpb=0de085bb474f64e4fdb2f1ff3268590792648c7b;p=linux-2.6-omap-h63xx.git

diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index 8af392fc6ef..4dbb8be1c99 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -2,7 +2,7 @@
 	=====================================================
 
 Notes Written on Jan 15, 2002:
-	Jens Axboe <axboe@suse.de>
+	Jens Axboe <jens.axboe@oracle.com>
 	Suparna Bhattacharya <suparna@in.ibm.com>
 
 Last Updated May 2, 2002
@@ -21,7 +21,7 @@ Credits:
 ---------
 
 2.5 bio rewrite:
-	Jens Axboe <axboe@suse.de>
+	Jens Axboe <jens.axboe@oracle.com>
 
 Many aspects of the generic block layer redesign were driven by and evolved
 over discussions, prior patches and the collective experience of several
@@ -477,9 +477,9 @@ With this multipage bio design:
   the same bi_io_vec array, but with the index and size accordingly modified)
 - A linked list of bios is used as before for unrelated merges (*) - this
   avoids reallocs and makes independent completions easier to handle.
-- Code that traverses the req list needs to make a distinction between
-  segments of a request (bio_for_each_segment) and the distinct completion
-  units/bios (rq_for_each_bio).
+- Code that traverses the req list can find all the segments of a bio
+  by using rq_for_each_segment.  This handles the fact that a request
+  has multiple bios, each of which can have multiple segments.
 - Drivers which can't process a large bio in one shot can use the bi_idx
   field to keep track of the next bio_vec entry to process.
   (e.g a 1MB bio_vec needs to be handled in max 128kB chunks for IDE)
@@ -664,14 +664,14 @@ in lvm or md.
 
 3.2.1 Traversing segments and completion units in a request
 
-The macros bio_for_each_segment() and rq_for_each_bio() should be used for
-traversing the bios in the request list (drivers should avoid directly
-trying to do it themselves). Using these helpers should also make it easier
-to cope with block changes in the future.
+The macro rq_for_each_segment() should be used for traversing the bios
+in the request list (drivers should avoid directly trying to do it
+themselves). Using these helpers should also make it easier to cope
+with block changes in the future.
 
-	rq_for_each_bio(bio, rq)
-		bio_for_each_segment(bio_vec, bio, i)
-			/* bio_vec is now current segment */
+	struct req_iterator iter;
+	rq_for_each_segment(bio_vec, rq, iter)
+		/* bio_vec is now current segment */
 
 I/O completion callbacks are per-bio rather than per-segment, so drivers
 that traverse bio chains on completion need to keep that in mind. Drivers
@@ -1097,7 +1097,7 @@ lock themselves, if required. Drivers that explicitly used the
 io_request_lock for serialization need to be modified accordingly.
 Usually it's as easy as adding a global lock:
 
-	static spinlock_t my_driver_lock = SPIN_LOCK_UNLOCKED;
+	static DEFINE_SPINLOCK(my_driver_lock);
 
 and passing the address to that lock to blk_init_queue().