block: bio: introduce helpers to get the 1st and last bvec

[cascardo/linux.git] / include / linux / bio.h

diff --git a/include/linux/bio.h b/include/linux/bio.h
index b9b6e04..cb68888 100644 (file)
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -310,6 +310,43 @@ static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
        bio->bi_flags &= ~(1U << bit);
 }
 
+static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
+{
+       *bv = bio_iovec(bio);
+}
+
+static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
+{
+       struct bvec_iter iter = bio->bi_iter;
+       int idx;
+
+       if (!bio_flagged(bio, BIO_CLONED)) {
+               *bv = bio->bi_io_vec[bio->bi_vcnt - 1];
+               return;
+       }
+
+       if (unlikely(!bio_multiple_segments(bio))) {
+               *bv = bio_iovec(bio);
+               return;
+       }
+
+       bio_advance_iter(bio, &iter, iter.bi_size);
+
+       if (!iter.bi_bvec_done)
+               idx = iter.bi_idx - 1;
+       else    /* in the middle of bvec */
+               idx = iter.bi_idx;
+
+       *bv = bio->bi_io_vec[idx];
+
+       /*
+        * iter.bi_bvec_done records actual length of the last bvec
+        * if this bio ends in the middle of one io vector
+        */
+       if (iter.bi_bvec_done)
+               bv->bv_len = iter.bi_bvec_done;
+}
+
 enum bip_flags {
        BIP_BLOCK_INTEGRITY     = 1 << 0, /* block layer owns integrity data */
        BIP_MAPPED_INTEGRITY    = 1 << 1, /* ref tag has been remapped */
@@ -318,16 +355,6 @@ enum bip_flags {
        BIP_IP_CHECKSUM         = 1 << 4, /* IP checksum */
 };
 
-#if defined(CONFIG_BLK_DEV_INTEGRITY)
-
-static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
-{
-       if (bio->bi_rw & REQ_INTEGRITY)
-               return bio->bi_integrity;
-
-       return NULL;
-}
-
 /*
  * bio integrity payload
  */
@@ -349,6 +376,16 @@ struct bio_integrity_payload {
        struct bio_vec          bip_inline_vecs[0];/* embedded bvec array */
 };
 
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
+{
+       if (bio->bi_rw & REQ_INTEGRITY)
+               return bio->bi_integrity;
+
+       return NULL;
+}
+
 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
 {
        struct bio_integrity_payload *bip = bio_integrity(bio);
@@ -795,6 +832,18 @@ static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
        return false;
 }
 
+static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
+                                                               unsigned int nr)
+{
+       return ERR_PTR(-EINVAL);
+}
+
+static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
+                                       unsigned int len, unsigned int offset)
+{
+       return 0;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 #endif /* CONFIG_BLOCK */