libceph: introduce BVECS data type
In preparation for rbd "fancy" striping, introduce ceph_bvec_iter for
working with bio_vec array data buffers. The wrappers are trivial, but
make it look similar to ceph_bio_iter.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index d7b9605..c7dfcb8 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -76,6 +76,7 @@ enum ceph_msg_data_type {
#ifdef CONFIG_BLOCK
CEPH_MSG_DATA_BIO, /* data source/destination is a bio list */
#endif /* CONFIG_BLOCK */
+ CEPH_MSG_DATA_BVECS, /* data source/destination is a bio_vec array */
};
static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type)
@@ -87,6 +88,7 @@ static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type)
#ifdef CONFIG_BLOCK
case CEPH_MSG_DATA_BIO:
#endif /* CONFIG_BLOCK */
+ case CEPH_MSG_DATA_BVECS:
return true;
default:
return false;
@@ -139,6 +141,42 @@ struct ceph_bio_iter {
#endif /* CONFIG_BLOCK */
+struct ceph_bvec_iter {
+ struct bio_vec *bvecs;
+ struct bvec_iter iter;
+};
+
+#define __ceph_bvec_iter_advance_step(it, n, STEP) do { \
+ BUG_ON((n) > (it)->iter.bi_size); \
+ (void)(STEP); \
+ bvec_iter_advance((it)->bvecs, &(it)->iter, (n)); \
+} while (0)
+
+/*
+ * Advance @it by @n bytes.
+ */
+#define ceph_bvec_iter_advance(it, n) \
+ __ceph_bvec_iter_advance_step(it, n, 0)
+
+/*
+ * Advance @it by @n bytes, executing BVEC_STEP for each bio_vec.
+ */
+#define ceph_bvec_iter_advance_step(it, n, BVEC_STEP) \
+ __ceph_bvec_iter_advance_step(it, n, ({ \
+ struct bio_vec bv; \
+ struct bvec_iter __cur_iter; \
+ \
+ __cur_iter = (it)->iter; \
+ __cur_iter.bi_size = (n); \
+ for_each_bvec(bv, (it)->bvecs, __cur_iter, __cur_iter) \
+ (void)(BVEC_STEP); \
+ }))
+
+#define ceph_bvec_iter_shorten(it, n) do { \
+ BUG_ON((n) > (it)->iter.bi_size); \
+ (it)->iter.bi_size = (n); \
+} while (0)
+
struct ceph_msg_data {
struct list_head links; /* ceph_msg->data */
enum ceph_msg_data_type type;
@@ -149,6 +187,7 @@ struct ceph_msg_data {
u32 bio_length;
};
#endif /* CONFIG_BLOCK */
+ struct ceph_bvec_iter bvec_pos;
struct {
struct page **pages; /* NOT OWNER. */
size_t length; /* total # bytes */
@@ -170,6 +209,7 @@ struct ceph_msg_data_cursor {
#ifdef CONFIG_BLOCK
struct ceph_bio_iter bio_iter;
#endif /* CONFIG_BLOCK */
+ struct bvec_iter bvec_iter;
struct { /* pages */
unsigned int page_offset; /* offset in page */
unsigned short page_index; /* index in array */
@@ -336,6 +376,8 @@ extern void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
u32 length);
#endif /* CONFIG_BLOCK */
+void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
+ struct ceph_bvec_iter *bvec_pos);
extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
bool can_fail);
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 3156914..528ccc9 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -57,6 +57,7 @@ enum ceph_osd_data_type {
#ifdef CONFIG_BLOCK
CEPH_OSD_DATA_TYPE_BIO,
#endif /* CONFIG_BLOCK */
+ CEPH_OSD_DATA_TYPE_BVECS,
};
struct ceph_osd_data {
@@ -76,6 +77,7 @@ struct ceph_osd_data {
u32 bio_length;
};
#endif /* CONFIG_BLOCK */
+ struct ceph_bvec_iter bvec_pos;
};
};
@@ -410,6 +412,9 @@ void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
struct ceph_bio_iter *bio_pos,
u32 bio_length);
#endif /* CONFIG_BLOCK */
+void osd_req_op_extent_osd_data_bvec_pos(struct ceph_osd_request *osd_req,
+ unsigned int which,
+ struct ceph_bvec_iter *bvec_pos);
extern void osd_req_op_cls_request_data_pagelist(struct ceph_osd_request *,
unsigned int which,
@@ -419,6 +424,9 @@ extern void osd_req_op_cls_request_data_pages(struct ceph_osd_request *,
struct page **pages, u64 length,
u32 alignment, bool pages_from_pool,
bool own_pages);
+void osd_req_op_cls_request_data_bvecs(struct ceph_osd_request *osd_req,
+ unsigned int which,
+ struct bio_vec *bvecs, u32 bytes);
extern void osd_req_op_cls_response_data_pages(struct ceph_osd_request *,
unsigned int which,
struct page **pages, u64 length,