[PATCH] Document bi_sector and sector_t
authorRoger Gammans <roger@computer-surgery.co.uk>
Wed, 4 Oct 2006 11:37:45 +0000 (13:37 +0200)
committerJens Axboe <axboe@nelson.home.kernel.dk>
Wed, 4 Oct 2006 17:32:09 +0000 (19:32 +0200)
Signed-Off-By: Roger Gammans <rgammans@computer-surgery.co.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
include/linux/bio.h
include/linux/types.h

index 711c321..092dbd0 100644 (file)
@@ -70,7 +70,8 @@ typedef void (bio_destructor_t) (struct bio *);
  * stacking drivers)
  */
 struct bio {
-       sector_t                bi_sector;
+       sector_t                bi_sector;      /* device address in 512 byte
+                                                  sectors */
        struct bio              *bi_next;       /* request queue link */
        struct block_device     *bi_bdev;
        unsigned long           bi_flags;       /* status, command, etc */
index 406d4ae..750f085 100644 (file)
@@ -129,8 +129,12 @@ typedef            __s64           int64_t;
 /* this is a special 64bit data type that is 8-byte aligned */
 #define aligned_u64 unsigned long long __attribute__((aligned(8)))
 
-/*
+/**
  * The type used for indexing onto a disc or disc partition.
+ *
+ * Linux always considers sectors to be 512 bytes long independently
+ * of the devices real block size.
+ *
  * If required, asm/types.h can override it and define
  * HAVE_SECTOR_T
  */