[PATCH 02/35] block: add REQ_OP definitions and bi_op/op fields

mchristi
2016-01-11T20:21:56Z

The following patches separate the operation (write, read, discard,
etc) from the flags in bi_rw/cmd_flags. This patch adds definitions
for request/bio operations, adds fields to the request/bio to set
them, and some temporary compat code so the kernel/modules can use
either one. In the final patches this compat code will be removed
when everything is converted.

Also, in this patch the REQ_OPs match the REQ rq_flag_bits ones
for compat reasons while all the code is converted in this set. In the
last patches that will also be removed.

Signed-off-by: Mike Christie <mchristi@redhat.com>
---
block/blk-core.c | 19 ++++++++++++++++---
include/linux/blk_types.h | 15 ++++++++++++++-
include/linux/blkdev.h | 1 +
include/linux/fs.h | 37 +++++++++++++++++++++++++++++++++++--
4 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 9b887e3..954a450 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1697,7 +1697,8 @@ void init_request_from_bio(struct request *req, struct bio *bio)
{
req->cmd_type = REQ_TYPE_FS;

- req->cmd_flags |= bio->bi_rw & REQ_COMMON_MASK;
+ /* tmp compat. Allow users to set bi_op or bi_rw */
+ req->cmd_flags |= (bio->bi_rw | bio->bi_op) & REQ_COMMON_MASK;
if (bio->bi_rw & REQ_RAHEAD)
req->cmd_flags |= REQ_FAILFAST_MASK;

@@ -2032,6 +2033,12 @@ blk_qc_t generic_make_request(struct bio *bio)
struct bio_list bio_list_on_stack;
blk_qc_t ret = BLK_QC_T_NONE;

+ /* tmp compat. Allow users to set either one or both.
+ * This will be removed when we have converted
+ * everyone in the next patches.
+ */
+ bio->bi_rw |= bio->bi_op;
+
if (!generic_make_request_checks(bio))
goto out;

@@ -2101,6 +2108,12 @@ EXPORT_SYMBOL(generic_make_request);
*/
blk_qc_t submit_bio(struct bio *bio)
{
+ /* tmp compat. Allow users to set either one or both.
+ * This will be removed when we have converted
+ * everyone in the next patches.
+ */
+ bio->bi_rw |= bio->bi_op;
+
/*
* If it's a regular read/write or a barrier with data attached,
* go through the normal accounting stuff before submission.
@@ -2972,8 +2985,8 @@ EXPORT_SYMBOL_GPL(__blk_end_request_err);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
{
- /* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw */
- rq->cmd_flags |= bio->bi_rw & REQ_WRITE;
+ /* tmp compat. Allow users to set bi_op or bi_rw */
+ rq->cmd_flags |= bio_data_dir(bio);

if (bio_has_data(bio))
rq->nr_phys_segments = bio_phys_segments(q, bio);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 86a38ea..6e49c91 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -48,9 +48,15 @@ struct bio {
struct block_device *bi_bdev;
unsigned int bi_flags; /* status, command, etc */
int bi_error;
- unsigned long bi_rw; /* bottom bits READ/WRITE,
+ unsigned long bi_rw; /* bottom bits rq_flags_bits
* top bits priority
*/
+ /*
+ * this will be a u8 in the next patches and bi_rw can be shrunk to
+ * a u32. For compat in these transistional patches op is a int here.
+ */
+ int bi_op; /* REQ_OP */
+

struct bvec_iter bi_iter;

@@ -242,6 +248,13 @@ 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,
+};
+
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 29189ae..35b9eb3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -96,6 +96,7 @@ struct request {
struct request_queue *q;
struct blk_mq_ctx *mq_ctx;

+ int op;
u64 cmd_flags;
unsigned cmd_type;
unsigned long atomic_flags;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index afa9df4..afca758 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2405,15 +2405,48 @@ extern void make_bad_inode(struct inode *);
extern bool is_bad_inode(struct inode *);

#ifdef CONFIG_BLOCK
+
+static inline bool op_is_write(int op)
+{
+ switch (op) {
+ case REQ_OP_WRITE:
+ case REQ_OP_WRITE_SAME:
+ case REQ_OP_DISCARD:
+ return true;
+ default:
+ 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)
+{
+ /*
+ * tmp cpmpat. Allow users to set either op or rw, until
+ * all code is converted in the next patches.
+ */
+ if (op_is_write(bio->bi_op))
+ return WRITE;
+
+ return bio->bi_rw & (RW_MASK | 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)
+{
+ /*
+ * tmp cpmpat. Allow users to set either op or rw, until
+ * all code is converted in the next patches.
+ */
+ if (op_is_write(bio->bi_op))
+ return WRITE;
+
+ return bio->bi_rw & 1;
+}

extern void check_disk_size_change(struct gendisk *disk,
struct block_device *bdev);
--
1.8.3.1