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 0933a14..9e93c92 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -445,6 +445,14 @@
__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)]))