[PATCH 02/45] block: add REQ_OP definitions and helpers

mchristi
2016-06-05T19:32:42Z

The following patches separate the operation (WRITE, READ, DISCARD,
etc) from the rq_flag_bits flags. This patch adds definitions for
request/bio operations (REQ_OPs) and adds request/bio accessors to
get/set the op.

In this patch the REQ_OPs match the REQ rq_flag_bits ones
for compat reasons while all the code is converted to use the
op accessors in the set. In the last patches the op will become a
number and the accessors and helpers in this patch will be dropped
or updated.

Signed-off-by: Mike Christie <mchristi@redhat.com>
---
include/linux/bio.h | 3 +++
include/linux/blk_types.h | 24 ++++++++++++++++++++++++
include/linux/blkdev.h | 10 +++++++++-
include/linux/fs.h | 26 ++++++++++++++++++++++++--
4 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 3bde942..09c5308 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -44,6 +44,9 @@
#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_SHIFT)
#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)

+#define bio_op(bio) (op_from_rq_bits((bio)->bi_rw))
+#define bio_set_op_attrs(bio, op, flags) ((bio)->bi_rw |= (op | flags))
+
/*
* upper 16 bits of bi_rw define the io priority of this bio
*/
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 77e5d81..6e60baa 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -242,6 +242,30 @@ enum rq_flag_bits {
#define REQ_HASHED (1ULL << __REQ_HASHED)
#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)

+enum req_op {
+ REQ_OP_READ,
+ REQ_OP_WRITE = REQ_WRITE,
+ REQ_OP_DISCARD = REQ_DISCARD,
+ REQ_OP_WRITE_SAME = REQ_WRITE_SAME,
+};
+
+/*
+ * tmp cpmpat. Users used to set the write bit for all non reads, but
+ * we will be dropping the bitmap use for ops. Support both until
+ * the end of the patchset.
+ */
+static inline int op_from_rq_bits(u64 flags)
+{
+ if (flags & REQ_OP_DISCARD)
+ return REQ_OP_DISCARD;
+ else if (flags & REQ_OP_WRITE_SAME)
+ return REQ_OP_WRITE_SAME;
+ else if (flags & REQ_OP_WRITE)
+ return REQ_OP_WRITE;
+ else
+ return REQ_OP_READ;
+}
+
typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE -1U
#define BLK_QC_T_SHIFT 16
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3d9cf32..49c2dbc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -200,6 +200,13 @@ struct request {
struct request *next_rq;
};

+#define req_op(req) (op_from_rq_bits((req)->cmd_flags))
+#define req_set_op(req, op) ((req)->cmd_flags |= op)
+#define req_set_op_attrs(req, op, flags) do { \
+ req_set_op(req, op); \
+ (req)->cmd_flags |= flags; \
+} while (0)
+
static inline unsigned short req_get_ioprio(struct request *req)
{
return req->ioprio;
@@ -597,7 +604,8 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)

#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)

-#define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1))
+#define rq_data_dir(rq) \
+ (op_is_write(op_from_rq_bits(rq->cmd_flags)) ? WRITE : READ)

/*
* Driver can handle struct request, if it either has an old style
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 65e4c51..62ca2f9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2465,14 +2465,36 @@ extern bool is_bad_inode(struct inode *);

#ifdef CONFIG_BLOCK
/*
+ * tmp cpmpat. Users used to set the write bit for all non reads, but
+ * we will be dropping the bitmap use for ops. Support both until
+ * the end of the patchset.
+ */
+static inline bool op_is_write(unsigned long flags)
+{
+ if (flags & (REQ_OP_WRITE | REQ_OP_WRITE_SAME | REQ_OP_DISCARD))
+ return true;
+ else
+ return false;
+}
+
+/*
* return READ, READA, or WRITE
*/
-#define bio_rw(bio) ((bio)->bi_rw & (RW_MASK | RWA_MASK))
+static inline int bio_rw(struct bio *bio)
+{
+ if (op_is_write(op_from_rq_bits(bio->bi_rw)))
+ return WRITE;
+
+ return bio->bi_rw & RWA_MASK;
+}

/*
* return data direction, READ or WRITE
*/
-#define bio_data_dir(bio) ((bio)->bi_rw & 1)
+static inline int bio_data_dir(struct bio *bio)
+{
+ return op_is_write(op_from_rq_bits(bio->bi_rw)) ? WRITE : READ;
+}

extern void check_disk_size_change(struct gendisk *disk,
struct block_device *bdev);