[PATCH 05/17] bio: cleanup rw usage
From: Tejun Heo
Date: Wed Apr 01 2009 - 09:47:23 EST
Impact: cleanup
bio confusingly uses @write_to_vm and @reading for data directions,
both of which mean the opposite of the usual block/bio convention of
using READ and WRITE w.r.t. IO devices. The only place where the
inversion is necessary is when caling get_user_pages_fast() in
bio_copy_user_iov() as the gup uses the VM convention of read/write
w.r.t. VM.
This patch converts all bio functions to use READ/WRITE rw parameter
and let the one place where inversion is necessary to rw == READ.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
block/blk-map.c | 10 +++++-----
fs/bio.c | 50 +++++++++++++++++++++++++-------------------------
include/linux/bio.h | 18 +++++++++---------
3 files changed, 39 insertions(+), 39 deletions(-)
diff --git a/block/blk-map.c b/block/blk-map.c
index b0b65ef..29aa60d 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -68,15 +68,15 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
int iov_count, unsigned int len, gfp_t gfp_mask)
{
struct bio *bio = ERR_PTR(-EINVAL);
- int read = rq_data_dir(rq) == READ;
+ int rw = rq_data_dir(rq);
if (!iov || iov_count <= 0)
return -EINVAL;
if (!map_data)
- bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
+ bio = bio_map_user_iov(q, NULL, iov, iov_count, rw, gfp_mask);
if (bio == ERR_PTR(-EINVAL))
- bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
+ bio = bio_copy_user_iov(q, map_data, iov, iov_count, rw,
gfp_mask);
if (IS_ERR(bio))
return PTR_ERR(bio);
@@ -177,7 +177,7 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
unsigned int len, gfp_t gfp_mask)
{
- int reading = rq_data_dir(rq) == READ;
+ int rw = rq_data_dir(rq);
int do_copy = 0;
struct bio *bio;
@@ -188,7 +188,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
do_copy = !blk_rq_aligned(q, kbuf, len) || object_is_on_stack(kbuf);
if (do_copy)
- bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
+ bio = bio_copy_kern(q, kbuf, len, gfp_mask, rw);
else
bio = bio_map_kern(q, kbuf, len, gfp_mask);
diff --git a/fs/bio.c b/fs/bio.c
index 80f61ed..70e5153 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -780,7 +780,7 @@ int bio_uncopy_user(struct bio *bio)
* @map_data: pointer to the rq_map_data holding pages (if necessary)
* @iov: the iovec.
* @iov_count: number of elements in the iovec
- * @write_to_vm: bool indicating writing to pages or not
+ * @rw: READ or WRITE
* @gfp_mask: memory allocation flags
*
* Prepares and returns a bio for indirect user io, bouncing data
@@ -789,8 +789,8 @@ int bio_uncopy_user(struct bio *bio)
*/
struct bio *bio_copy_user_iov(struct request_queue *q,
struct rq_map_data *map_data,
- struct sg_iovec *iov, int iov_count,
- int write_to_vm, gfp_t gfp_mask)
+ struct sg_iovec *iov, int iov_count, int rw,
+ gfp_t gfp_mask)
{
struct bio_map_data *bmd;
struct bio_vec *bvec;
@@ -823,7 +823,8 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
if (!bio)
goto out_bmd;
- bio->bi_rw |= (!write_to_vm << BIO_RW);
+ if (rw == WRITE)
+ bio->bi_rw |= 1 << BIO_RW;
ret = 0;
@@ -872,7 +873,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
*/
if (unlikely(map_data && map_data->null_mapped))
bio->bi_flags |= (1 << BIO_NULL_MAPPED);
- else if (!write_to_vm) {
+ else if (rw == WRITE) {
ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
if (ret)
goto cleanup;
@@ -897,7 +898,7 @@ out_bmd:
* @map_data: pointer to the rq_map_data holding pages (if necessary)
* @uaddr: start of user address
* @len: length in bytes
- * @write_to_vm: bool indicating writing to pages or not
+ * @rw: READ or WRITE
* @gfp_mask: memory allocation flags
*
* Prepares and returns a bio for indirect user io, bouncing data
@@ -905,21 +906,21 @@ out_bmd:
* call bio_uncopy_user() on io completion.
*/
struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
- unsigned long uaddr, unsigned int len,
- int write_to_vm, gfp_t gfp_mask)
+ unsigned long uaddr, unsigned int len, int rw,
+ gfp_t gfp_mask)
{
struct sg_iovec iov;
iov.iov_base = (void __user *)uaddr;
iov.iov_len = len;
- return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
+ return bio_copy_user_iov(q, map_data, &iov, 1, rw, gfp_mask);
}
static struct bio *__bio_map_user_iov(struct request_queue *q,
struct block_device *bdev,
struct sg_iovec *iov, int iov_count,
- int write_to_vm, gfp_t gfp_mask)
+ int rw, gfp_t gfp_mask)
{
int i, j;
size_t tot_len = 0;
@@ -967,8 +968,8 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
const int local_nr_pages = end - start;
const int page_limit = cur_page + local_nr_pages;
- ret = get_user_pages_fast(uaddr, local_nr_pages,
- write_to_vm, &pages[cur_page]);
+ ret = get_user_pages_fast(uaddr, local_nr_pages, rw == READ,
+ &pages[cur_page]);
if (ret < local_nr_pages) {
ret = -EFAULT;
goto out_unmap;
@@ -1008,7 +1009,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
/*
* set data direction, and check if mapped pages need bouncing
*/
- if (!write_to_vm)
+ if (rw == WRITE)
bio->bi_rw |= (1 << BIO_RW);
bio->bi_bdev = bdev;
@@ -1033,14 +1034,14 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
* @bdev: destination block device
* @uaddr: start of user address
* @len: length in bytes
- * @write_to_vm: bool indicating writing to pages or not
+ * @rw: READ or WRITE
* @gfp_mask: memory allocation flags
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len, int write_to_vm,
+ unsigned long uaddr, unsigned int len, int rw,
gfp_t gfp_mask)
{
struct sg_iovec iov;
@@ -1048,7 +1049,7 @@ struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
iov.iov_base = (void __user *)uaddr;
iov.iov_len = len;
- return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
+ return bio_map_user_iov(q, bdev, &iov, 1, rw, gfp_mask);
}
/**
@@ -1057,20 +1058,19 @@ struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
* @bdev: destination block device
* @iov: the iovec.
* @iov_count: number of elements in the iovec
- * @write_to_vm: bool indicating writing to pages or not
+ * @rw: READ or WRITE
* @gfp_mask: memory allocation flags
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
- struct sg_iovec *iov, int iov_count,
- int write_to_vm, gfp_t gfp_mask)
+ struct sg_iovec *iov, int iov_count, int rw,
+ gfp_t gfp_mask)
{
struct bio *bio;
- bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
- gfp_mask);
+ bio = __bio_map_user_iov(q, bdev, iov, iov_count, rw, gfp_mask);
if (IS_ERR(bio))
return bio;
@@ -1219,23 +1219,23 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
* @data: pointer to buffer to copy
* @len: length in bytes
* @gfp_mask: allocation flags for bio and page allocation
- * @reading: data direction is READ
+ * @rw: READ or WRITE
*
* copy the kernel address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
- gfp_t gfp_mask, int reading)
+ gfp_t gfp_mask, int rw)
{
struct bio *bio;
struct bio_vec *bvec;
int i;
- bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
+ bio = bio_copy_user(q, NULL, (unsigned long)data, len, READ, gfp_mask);
if (IS_ERR(bio))
return bio;
- if (!reading) {
+ if (rw == WRITE) {
void *p = data;
bio_for_each_segment(bvec, bio, i) {
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 4bf7442..45f56d2 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -387,24 +387,24 @@ int bio_get_nr_vecs(struct block_device *bdev);
sector_t bio_sector_offset(struct bio *bio, unsigned short index,
unsigned int offset);
struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len,
- int write_to_vm, gfp_t gfp_mask);
+ unsigned long uaddr, unsigned int len, int rw,
+ gfp_t gfp_mask);
struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
- struct sg_iovec *iov, int iov_count,
- int write_to_vm, gfp_t gfp_mask);
+ struct sg_iovec *iov, int iov_count, int rw,
+ gfp_t gfp_mask);
void bio_unmap_user(struct bio *bio);
struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
- unsigned long uaddr, unsigned int len,
- int write_to_vm, gfp_t gfp_mask);
+ unsigned long uaddr, unsigned int len, int rw,
+ gfp_t gfp_mask);
struct bio *bio_copy_user_iov(struct request_queue *q,
struct rq_map_data *map_data,
- struct sg_iovec *iov, int iov_count,
- int write_to_vm, gfp_t gfp_mask);
+ struct sg_iovec *iov, int iov_count, int rw,
+ gfp_t gfp_mask);
int bio_uncopy_user(struct bio *bio);
struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
gfp_t gfp_mask);
struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
- gfp_t gfp_mask, int reading);
+ gfp_t gfp_mask, int rw);
void bio_set_pages_dirty(struct bio *bio);
void bio_check_pages_dirty(struct bio *bio);
void zero_fill_bio(struct bio *bio);
--
1.6.0.2
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