From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 8 Aug 2008 09:17:12 +0000 (+0200)
Subject: block: add bio_has_data() to detect whether a bio carries data or not
X-Git-Tag: v2.6.28-rc1~733^2~130
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=7a67f63b3233ff28e753854fe27891c44f8588ae;p=linux-2.6-omap-h63xx.git

block: add bio_has_data() to detect whether a bio carries data or not

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

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 0933a14e641..9e93c929947 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -445,6 +445,14 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 #define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
 
+/*
+ * Check whether this bio carries any data or not. A NULL bio is allowed.
+ */
+static inline int bio_has_data(struct bio *bio)
+{
+	return bio && bio->bi_io_vec != NULL;
+}
+
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
 #define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))